Injection molded light guide member and head mounted display

Abstract

The invention provides an injection molded light guide member and a head mounted display having the same. Provided is an injection-molded light guide member capable of providing a high-resolution image without image distortion, while suppressing undesirable situations such as uneven brightness, uneven color, and rainbow patterns, even when a partial mirror having a reflectance characteristic with polarization selectivity is disposed in an input coupler, a waveguide unit, and an output coupler. This injection-molded light guide member is provided with: a base material part; an input coupler that enters light from the image display device into the light guide member; light guide parts on two opposite surfaces for guiding the incident light by a plurality of repeated reflections; and an output coupler that extracts light from the light guide body while causing the guided light to face an eye of an observer by means of refraction, diffraction, and reflection functions, the absolute value of the photoelastic coefficient being 10 * 10-12 Pa-1 or less, and a partially reflecting mirror that transmits a portion of the light and reflects the remaining light being formed on at least one of the three surfaces of the waveguide section and the output coupler.

Description

Technical Field

[0001] This invention relates to injection-molded light guide components and head-mounted displays. Background Technology

[0002] In recent years, the development of devices for Virtual Reality (VR), Augmented Reality (AR), and extended reality (XR), which are collectively referred to as virtual reality, has been actively underway.

[0003] The boundaries of these frameworks have become increasingly blurred. In particular, devices that allow visual recognition of the real world through a lens in front of the observer's eye (viewpoint) using a perspective approach belong to the category of AR head-mounted displays. Regarding the basic structure of AR head-mounted displays, their optical systems are specifically as follows... Figure 1 As shown.

[0004] Reference Figure 1 The basic structure of an AR head-mounted display is as follows: After generating image light using an image display device 12, the image light is incident into the transparent light guide member 11 via a prism, mirror, diffraction grating, or holographic element serving as an input coupler in the light incident section 111 of the transparent light guide member 11. After waveguided by the waveguide section (outer side waveguide section 113 and eye side waveguide section 112) within the aforementioned light guide member 11 using total internal reflection, the image light is output towards the user's eyes via a mirror, diffraction grating, or holographic element configured to disrupt total internal reflection, and extracted from the light extraction section 115. This allows the user to observe the real world (external light 14) through the transparent waveguide path via the pupil 13, while simultaneously observing the real world through the pupil 13 using the aforementioned optical system to superimpose the image light onto the real world. Such a device is disclosed in Patent Documents 1 and 2.

[0005] These devices require comfortable wear and viewing of images without discomfort. To achieve overall lightweighting, miniaturization, and thinning of the devices, and to display large-screen images with various information, a wide-viewing-angle optical system is essential. Furthermore, an optical system characterized by guiding image light waves into thin-walled light guide components is indispensable for realizing thin and lightweight devices. High-level implementation of these technologies is highly anticipated for applications in the post-smartphone era.

[0006] As an example of such an optical system, Patent Document 1 illustrates the following: Image light is collimated and incident into a waveguide path; diffraction is generated by a volumetric holographic optical element that records interference fringes with a tilted refractive index distribution, formed by an input coupler; total internal reflection is used to waveguide the light in the waveguide path; and the light is diffracted at the eye side by a volumetric holographic optical element formed by an output coupler, and extracted to the observer's eye side. Furthermore, Patent Document 2 illustrates a structure in which a plurality of wire grating mirrors are arranged alternately orthogonally on the output coupler with their reflection axes aligned.

[0007] Existing technical documents

[0008] Patent documents

[0009] Patent document 1: International Publication No. 2018 / 012108.

[0010] Patent Document 2: Japanese Patent Application Publication No. 2019-101370.

[0011] Patent document 3: Japanese Patent Application Publication No. 2021-162621.

[0012] Patent document 4: International Publication No. 2021 / 182598.

[0013] Patent document 5: Japanese Patent Application Publication No. 2023-059010. Summary of the Invention

[0014] However, in such optical systems, when the prisms, mirrors, diffraction gratings, and holographic elements used for the input and output couplers exhibit polarization selectivity, the image light may be adversely affected by the destruction or localized polarization of the image light during its waveguide journey within the light guide component. While glass light guide components minimize the impact of polarization selectivity and allow for the extraction of image light as designed, the high refractive index and flatness of the glass facing the waveguide are extremely expensive, becoming a major obstacle to the widespread adoption of AR headsets targeting the future smartphone era. Therefore, the use of resin waveguides and resin light guide components is required, but the impact of polarization selectivity has not yet been fully verified.

[0015] Furthermore, when using resin-based light guide components, as in the structure disclosed in Patent Document 3, if total internal reflection is required for waveguided image light in the waveguide section, there are no options for materials with a high refractive index like glass in the resin composition. The substrate has a low refractive index, thus leading to a problem of a larger critical angle. Additionally, waveguided light at an incident angle greater than the critical angle is required to maintain total internal reflection. Therefore, a narrow eye-tracking range cannot be designed because the image cannot be waveguided with a narrow spacing, and the viewing angle (the viewing angle of the virtual image), which is related to the size of the virtual image, cannot be expanded.

[0016] Furthermore, when using resin to manufacture light guide components, there is a problem of obtaining molded sheets with high flatness (parallelism). Prior art has involved the following research: injecting methyl methacrylate (MMA) monomer into a synthetic quartz cell with high mirror surface and a thickness tolerance of 1 μm, curing it through free radical polymerization to produce a cast plastic sheet, and then chemically and mechanically polishing the cast plastic sheet to produce a transparent sheet with high flatness (Patent Documents 3 and 4). However, due to the durability of the mold and the length of the processing steps, mass production is lacking. Furthermore, considering it as a lens for eyeglasses, it cannot have a curved surface for vision correction and it is difficult to give the frame a fixed shape. Therefore, there is an urgent need for light guide components obtained by injection molding.

[0017] Furthermore, while Patent Document 4 describes preferred flatness and parallelism for light guide plates with diffraction gratings manufactured by injection molding, it does not provide evaluation results for these characteristics in the embodiments, but merely shows ideal common ranges. Therefore, basically, in order to achieve high surface accuracy, grinding is a prerequisite, and for example, techniques that can be achieved even in cases such as bending of the light guide plate have not been sufficiently studied.

[0018] The present invention was made in view of the above circumstances. Its objective is to provide an injection-molded light guide component and a head-mounted display having the light guide component. Even if the injection-molded light guide component has a partial reflector with polarization-selective reflectivity characteristics disposed on at least one of the input coupler, waveguide, and output coupler, it can suppress defects such as uneven brightness, uneven color, and rainbow patterns, and can provide an image without deformation caused by surface damage.

[0019] This invention is the result of dedicated research conducted by the inventors in view of the aforementioned problems.

[0020] The inventors have discovered that by using a light guide component with sufficiently high heat resistance, a low photoelasticity, and formed from a thermoplastic resin composition having a ring structure in the main chain or side chains, exhibiting low anisotropy of residual stress during molding and excellent surface accuracy, it is possible to provide clear images with low post-molding birefringence and minimal influence of environmental changes on surface accuracy and dimensional variations. Furthermore, it has been discovered that by utilizing a partially reflecting mirror that transmits a portion of the light and reflects the remaining portion, a light guide component can be obtained that solves the aforementioned critical angle problem and imparts new functions.

[0021] That is, the present invention is as follows.

[0022] [1] An injection-molded light guide component is used in an image display device having an eyepiece optical system that guides light from an image display element toward an observer's eyeball. The injection-molded light guide component comprises: a substrate portion; an input coupler for incident light from the image display device into the light guide body; waveguide portions on opposite sides that waveguide the incident light through multiple repeated reflections; and an output coupler for directing the waveguided light toward the observer's eye and extracting light from the light guide component using any one of refraction, diffraction, and reflection. The absolute value of the photoelastic coefficient of the injection-molded light guide component is 10 × 10⁻⁶. -12 Pa -1 Hereinafter, on at least one of the three surfaces of the waveguide portion on both sides and the surface of the output coupler, a partial reflector is formed that transmits a portion of the light and reflects the remaining portion of the light. When the partial reflector is used for reflection at an incident angle of 30°, the difference between the reflectivity of the first polarized light (S-polarized light) and the P-polarized light (P-polarized light) (orthogonal to the first polarized light) is 10% or more and less than 40%. The in-plane phase difference within the effective area of ​​the waveguide portion is within 20 nm. The substrate portion is composed of a thermoplastic resin composition having a ring structure in the main chain or side chain, and the glass transition temperature (Tg) is 115 to 150°C.

[0023] [2] The injection-molded light guide component as described in [1] is characterized in that the shortest distance between the waveguide portions on both sides is 0.6 mm or more and 25 mm or less, the projected length of the waveguide direction of the light guide component is 10 mm or more and 50 mm or less, and the PV value (Peak-to-Valley) in the effective area for waveguide of light on both sides is 10.0 μm or less.

[0024] [3] The injection-molded light guide component as described in [1] or [2] is characterized in that one of the waveguide portions on both sides is an outer side waveguide portion, and the outer side waveguide portion is formed with a partial reflector that transmits a portion of the light and reflects the remaining portion of the light.

[0025] [4] The injection-molded light guide component as described in any one of [1] to [3] is characterized in that, in the reflection at the waveguide section, when the first polarized light with a wavelength of 500 to 600 nm as S-polarized light is incident from the light incident section, and after the light is waveguided by the waveguide section, when the light is extracted from the light extraction section via the output coupler, the value obtained by dividing the ratio (Tp / Tc) by the ratio (Rs / Rp) of the surface with the largest S-polarized light reflectivity to P-polarized light reflectivity of the partial reflector is 5 or more, and the ratio (Tp / Tc) is the ratio of the amount of light Tp extracted by the polarizing plate arranged with the first polarization axis aligned with the transmission axis to the amount of light Tc extracted by the polarizing plate arranged with the first polarization axis orthogonal to the transmission axis.

[0026] [5] The injection-molded light guide component as described in [4] is characterized in that the value obtained by dividing the ratio (Tp / Tc) by the ratio (Rs / Rp) of the surface with the largest ratio (Rs / Rp) is 10 or more.

[0027] [6] The injection-molded light guide component as described in any one of [1] to [5] is characterized in that the output coupler is formed with a partial reflector that transmits a portion of the light and reflects the remaining portion of the light.

[0028] [7] The injection-molded light guide component as described in any one of [1] to [6] is characterized in that the thermoplastic resin composition contains 0.5 to 2.8% by mass of a higher fatty acid ester.

[0029] [8] The injection-molded light guide component as described in any one of [1] to [7] is characterized in that the thermoplastic resin composition is a methacrylic resin composition.

[0030] [9] A head-mounted display, characterized in that the head-mounted display comprises any one of the injection-molded light guide components described in [1] to [8].

[0031]

[10] The head-mounted display as described in [9] is characterized in that, in at least one of the light output section and the eye-side waveguide section, the reflectivity of S-polarized light at an incident angle of 5° is greater than that of P-polarized light, and the difference between the reflectivity of S-polarized light and the reflectivity of P-polarized light is 5% or more.

[0032]

[11] The head-mounted display as described in [9] or

[10] is characterized in that, on a portion or all of the two sides of the waveguide portion on both sides, a partial reflector is formed to transmit a portion of light and reflect the remaining portion of light, so as to waveguide the light at an incident angle smaller than the critical angle of the substrate portion.

[0033]

[12] The head-mounted display as described in any one of [9] to

[11] is characterized in that the observer's eyeball is connected to the output coupler of the light guide component, and a linear polarizer is provided on a straight line extending outward.

[0034]

[13] The head-mounted display as described in any one of [9] to

[12] is characterized in that the observer's eyeball is connected to the output coupler of the light guide component, and a linear polarizer and a half-wave plate are sequentially provided from the outside along a straight line extending outward, or a linear polarizer and a phase difference layer that imparts a phase difference of half a wavelength are sequentially provided from the outside.

[0035] According to the present invention, an injection-molded light guide component and a head-mounted display having the injection-molded light guide component can be provided. When the injection-molded light guide component is provided with a partial reflector having polarization-selective reflectivity characteristics in the input coupler, waveguide section and output coupler, it can also suppress defects such as brightness non-uniformity, color non-uniformity and rainbow patterns and provide images. Attached Figure Description

[0036] Figure 1 This is a conceptual diagram of an optical system used to illustrate the basic components of an AR head-mounted display.

[0037] Figure 2A This is a conceptual diagram simulating an optical system of an AR head-mounted display equipped with a light guide component according to an embodiment of the present invention.

[0038] Figure 2B This is a conceptual diagram simulating an optical system of an AR head-mounted display equipped with a light guide component according to an embodiment of the present invention.

[0039] Figure 2C This is a conceptual diagram simulating an optical system of an AR head-mounted display equipped with a light guide component according to an embodiment of the present invention.

[0040] Figure 3 This is a conceptual diagram illustrating the measurement of polarization retention characteristics in an optical system with multiple viewpoints.

[0041] Figure 4 This diagram illustrates the vibration axes of S-polarized and P-polarized light reflected within the light guide component.

[0042] Figure 5It is a diagram illustrating the vibration axes of S-polarized and P-polarized light reflected from the ground, water surface, etc.

[0043] Figure 6 This is a conceptual diagram illustrating the configuration of polarized light when a linear polarizing plate is used to block strongly reflected external light.

[0044] Figure 7 This is a conceptual diagram illustrating a configuration that includes a linear polarizer and a phase détravisor to block strongly reflected external light and improve the light utilization efficiency of the waveguide within the light guide component.

[0045] Figure 8 This is a conceptual diagram for measuring the PV value of the substrate surface of the light incident part, waveguide part, input coupler, and output coupler.

[0046] Figure 9 This is an example of the polarization reflectivity characteristics of a partial reflector in this embodiment.

[0047] Figure 10A This is a conceptual diagram showing the outline of an experimental setup for evaluating the polarization retention characteristics when incident at an angle of 45° relative to the waveguide.

[0048] Figure 10B This is a conceptual diagram showing the outline of an experimental setup for evaluating the polarization retention characteristics when incident at an incident angle of 40° relative to the waveguide section.

[0049] Figure 11 This is a conceptual diagram of an image evaluation using the light guide component of this embodiment combined with an AR head-mounted device.

[0050] Figure 12 This is a conceptual diagram of molded article holding implemented as an example related to a method of holding a molded article in the air after molding, in Example 2.

[0051] Figure 13 This is a conceptual diagram of the configuration of an AR head-mounted device shown in Embodiment 16, one of the embodiments of this invention.

[0052] The reference numerals in the attached figures are explained below.

[0053] 11: Light guide components.

[0054] 12: Image display element.

[0055] 111: Light incident section.

[0056] 112: Eye-side waveguide section.

[0057] 113: External waveguide section.

[0058] 114: Output coupler.

[0059] 115: Light extraction section.

[0060] 13: Pupil.

[0061] 14: External light.

[0062] 71: Laser diode.

[0063] 72: Gran-Thompson prism polarizing element.

[0064] 73: Light guide components.

[0065] 731: Light incident section and input coupler.

[0066] 732: External waveguide section.

[0067] 733: Eye-side waveguide section.

[0068] 734: Output coupler.

[0069] 735: Light extraction section.

[0070] 74: Linear polarizing plate.

[0071] 75: Power meter.

[0072] 1111: Image display element.

[0073] 1112: Opening mask.

[0074] 1113: Collimating optical system.

[0075] 1114: Linear polarizing element.

[0076] 1115: Light guide components. Detailed Implementation

[0077] Hereinafter, a method for implementing the present invention (hereinafter referred to as "this embodiment") will be described in detail. The present invention is not limited to the following description and can be implemented in various modifications within the scope of its spirit.

[0078] In descriptions of light polarization states and phase differences, concepts such as linear polarization, circular polarization, elliptical polarization, and phase differences of 1 / 4λ (1 / 4 wavelength) and 1 / 2λ (1 / 2 wavelength) generally refer to states with a wide range of defined dimensions. Therefore, these errors do not hinder the essential effects of the present invention. Furthermore, the phase difference generated in each optical element is the phase difference of light relative to the wavelength λ. The wavelength λ can primarily be any wavelength within the visible light region, for example, λ = 587.6 nm, but is not limited to this.

[0079] [Explanation of Terminology]

[0080] In this specification, "hydrocarbon group" is a monovalent group, including straight-chain, branched, or cyclic saturated hydrocarbon groups, unsaturated hydrocarbon groups, or aromatic groups. For example, "hydrocarbon group" is a group selected from the group consisting of alkyl (e.g., the alkyl group described above), alkenyl (e.g., the alkenyl group described above), aryl (e.g., the aryl group described above), aryloxy (e.g., the aryloxy group described above), aralkyl (e.g., the aralkyl group described above), and alkoxy (e.g., the alkoxy group described above).

[0081] In this specification, "aliphatic hydrocarbon group" refers to a group after removing one or more hydrogen atoms bonded to an aliphatic carbon atom of an aliphatic compound. Specifically, a monovalent aliphatic hydrocarbon group refers to a group after removing one hydrogen atom bonded to an aliphatic carbon atom of an aliphatic compound, and a divalent aliphatic hydrocarbon group refers to a group after removing two hydrogen atoms bonded to an aliphatic carbon atom of an aliphatic compound. Furthermore, in this specification, "aliphatic hydrocarbon group" refers to a group whose main chain is an aliphatic hydrocarbon, which may contain an aromatic ring or the like in some parts. Examples of divalent aliphatic hydrocarbon groups include, for example, alkylene groups that may have substituents, cycloalkylene groups that may have substituents, alkenyl groups that may have substituents, cycloalkenyl groups that may have substituents, and alkyl polyalkenyl groups that may have substituents (preferably with 2 to 10 double bonds, more preferably 2 to 6, further preferably 2 to 4, and even more preferably 2).

[0082] In this specification, "aromatic hydrocarbon group" refers to the group formed by removing a hydrogen atom from the aromatic ring of an aromatic hydrocarbon compound. Specific examples include phenyl, biphenyl, tolyl, indene, naphthyl, anthracene, fluorenyl, pyrene, phenanthryl, and mesitylene.

[0083] In this specification, aryl alkyl groups include, for example, benzyl, phenylethyl, phenylpropyl, naphthylmethyl, naphthylethyl, naphthylpropyl, etc.

[0084] In this specification, aryl groups include, for example, phenyl, tolyl, xylyl, naphthyl, biphenyl, anthracene, phenanthrene, etc.

[0085] In this specification, alkyl groups can be linear or branched, and examples include methyl, ethyl, n-propyl, isopropyl, n-butyl, sec-butyl, isobutyl, tert-butyl, 2-methylbutyl, n-pentyl, 2-pentyl, 3-pentyl, 2,2-dimethylpropyl, n-hexyl, heptyl, n-octyl, 1,1,3,3-tetramethylbutyl, 2-ethylhexyl, nonyl, decyl, undecyl, dodecyl, etc.

[0086] In this specification, examples of halogen atoms include, for example, fluorine atoms, chlorine atoms, bromine atoms, and iodine atoms.

[0087] In this specification, alkoxy groups, for example, include methoxy, ethoxy, n-butoxy, methoxyethoxy, etc.

[0088] In this specification, examples of cycloalkyl groups include cyclopropyl, cyclopropylmethyl, cyclobutyl, cyclopentyl, cyclohexyl, cyclohexylmethyl, trimethylcyclohexyl, thujyl, norbornyl, borneol, norcaryl, caryl, menthyl, norpinyl, pinyl, 1-adamantyl, 2-adamantyl, etc.

[0089] [Injection-molded light guide components]

[0090] The injection-molded light guide component of this embodiment is an injection-molded light guide component (hereinafter, sometimes simply referred to as "light guide component") for an image display device having an eyepiece optical system that guides light from an image display element toward an observer's eyeball. The injection-molded light guide component is characterized by comprising: a substrate portion; an input coupler for incident light from the image display device into the light guide body; waveguide portions on opposite sides that waveguide the incident light through multiple repeated reflections; and an output coupler for directing the waveguided light toward the observer's eye and extracting light from the light guide body using any one of refraction, diffraction, and reflection; the absolute value of the photoelastic coefficient of the injection-molded light guide component is 10 × 10⁻⁶. -12 Pa -1 Hereinafter, on at least one of the three surfaces of the waveguide portion on both sides and the surface of the output coupler, a partial reflector is formed that transmits a portion of the light and reflects the remaining portion of the light. When the partial reflector is used for reflection at an incident angle of 30°, the difference between the reflectivity of the first polarized light (S-polarized light) and the P-polarized light (P-polarized light) (orthogonal to the first polarized light) is 10% or more and less than 40%. The in-plane phase difference within the effective area of ​​the waveguide portion is within 20 nm. The substrate portion is composed of a thermoplastic resin composition having a ring structure in the main chain or side chain, and the glass transition temperature (Tg) is 115 to 150°C.

[0091] According to the above-mentioned injection-molded light guide component, when partial reflectors with polarization-selective reflectivity characteristics are arranged in the input coupler, waveguide, and output coupler, it is also possible to suppress defects such as uneven brightness, uneven color, and rainbow patterns, and provide images.

[0092] The inventors have discovered that, by using a light guide component with sufficiently high heat resistance, a low photoelasticity, and formed from a thermoplastic resin composition having a ring structure in the main chain or side chains, and exhibiting low anisotropy of residual stress, it is possible to obtain a light guide component that can provide clear images with low birefringence after molding and minimal influence of environmental changes on surface accuracy and dimensional variations. Furthermore, it has been discovered that by utilizing a partially reflecting mirror that transmits a portion of the light and reflects the remaining portion, a light guide component can be obtained that solves the aforementioned critical angle problem and imparts new functions.

[0093] Specifically, by utilizing a partially reflective mirror (e.g., a design with 30% reflectivity and 70% transmittance) that transmits a portion of the light and reflects the remainder, a waveguide can be forcibly formed within the substrate of the light guide component through reflection, independent of the critical angle. Furthermore, a light guide component that can guide image light without damage using total internal reflection has been discovered, provided the incident angle is large enough.

[0094] In existing technologies, waveguide sections do not actively utilize partial reflectors. As another characteristic of partial reflectors, the inventors noted that, depending on the configuration of the reflector, the reflectivity exhibits polarization dependence, and thus its characteristics vary with the incident angle. Furthermore, as such a partial reflector, for example, when using a reflector with a reflectivity difference of 10% or more between the first polarized light and the second polarized light orthogonal to the first polarized light at an incident angle of 30°, even if the reflectivity is designed to be 30% in the unpolarized state—for example, using a partial reflector with 50% S-polarized reflectivity and 10% P-polarized reflectivity—and the input image light is incident with S-polarized light, the image light utilization efficiency corresponding to the number of reflections in the waveguide section can be improved.

[0095] However, the inventors discovered that when such a waveguide and output coupler have polarization-selective reflectivity (or transmittance) characteristics, the polarization state of the image light passing through the waveguide is disordered due to the birefringence of the resin substrate, resulting in uneven brightness, rainbow patterns, and color inhomogeneity of the image. By manufacturing a light guide component made of the low birefringence resin composition of the present invention, it is possible to provide a light guide component that does not produce uneven brightness, triple rainbow patterns, and color inhomogeneity of the image.

[0096] The injection-molded light guide component of this embodiment (hereinafter, sometimes simply referred to as "light guide component") can be any light guide component that includes other components (e.g., polarizing plate, waveplate, phase difference coating, metal mirror coating, anti-reflection coating, hard coating, other functional coatings, etc.) as long as it does not impair the effect of the present invention. The aforementioned other components may be one or more.

[0097] -constitute-

[0098] The shape of the light guide component is not particularly limited. Essential components include an input coupler for directing light into the light guide body, a waveguide section for waveguided light using repeated reflections, and an output coupler for extracting light. Furthermore, the light guide component includes a light incident section for directing light and a light extraction section for extracting the waveguided light to the outside. It should be noted that the exit section can have the same structure as the output coupler.

[0099] There are no particular restrictions on the input and output couplers. In addition to diffraction gratings made of gratings, volumetric holographic optical elements, and diffraction gratings made of liquid crystals, mirrors made of metal thin films and partial mirrors made of dielectric multilayer films can also be used.

[0100] When the input coupler is constructed using a reflective surface, a reflective mirror with no light loss and high reflectivity is preferred. Conversely, when it is constructed using a diffractive surface, a diffractive element with no light loss and high diffraction efficiency is preferred.

[0101] When the input coupler is configured as a transmissive surface, it is preferable to implement an anti-reflective coating that suppresses reflectivity.

[0102] In addition, the input coupler and output coupler do not need to be parallel to the two surfaces constituting the waveguide section; they can also be formed as inclined surfaces that constitute the prism section for bending image light by using reflection.

[0103] The waveguide section is preferably a structure capable of utilizing total internal reflection. However, when the critical angle is limited in terms of expanding the viewing angle and designing the eye movement range, a partial reflector is preferred. However, when a partial reflector is used, light intensity is attenuated through repeated reflection. Therefore, considering the brightness of the image light that the observer can visually recognize, it is preferable to set the reflectivity of the image light high by adjusting the reflectivity of the partial reflector and utilizing the polarized reflectivity characteristics. It should be noted that, even when using a partial reflector, if the condition for total internal reflection is met, the waveguide can be constructed without light loss, which is therefore more preferable.

[0104] Furthermore, the waveguide section has two surfaces. One surface is called the outer-side waveguide section, and the other surface is called the eye-side waveguide section. It should be noted that the eye-side waveguide section is the waveguide section closest to the observer's eyeball, and the other waveguide section is the outer-side waveguide section.

[0105] Here, refer to Figures 2A to 2C This section describes an example of the configuration of the light guide member in this embodiment. As an input coupler that places light from the image display element at the light incident portion of the light guide member, in... Figure 2A Using prisms, in Figure 2B The text discusses the use of diffraction gratings, holographic elements (holographic optical elements), and liquid crystal diffraction elements in [the context of holography]. Figure 2C The light is incident into the light guide component using a mirror, a partial mirror, and a polarizing beam splitter (reflective polarizing element). After total internal reflection in the waveguide section (outer side waveguide section and eye side waveguide section) within the light guide component, the image light is output towards the user's pupil via a mirror, diffraction grating, or holographic element configured as an output coupler to break total internal reflection. This image light is then extracted from the light extraction section, allowing the observer to observe the light passing through the light guide component through their pupil. It should be noted that... Figures 2A to 2C In this configuration, a linear polarizing element is positioned between the image display element and the light guide component. Alternatively, a collimating optical system (not shown) can be separately positioned between the image display element and the light guide component. Additionally, a correction prism can be attached to the output coupler.

[0106] Without compromising the effectiveness of the present invention, the surface of the light guide component of this embodiment can be further functionalized, for example, by hard coating, anti-reflection treatment, metal mirror treatment, phase retardation layer application, transparent conductive treatment, electromagnetic wave blocking treatment, or gas shielding treatment. The thickness of these functional layers is not particularly limited, and is typically in the range of 0.01 to 10 μm. When it is necessary to avoid reflection at the interface due to the refractive index difference between the substrate and the functional layer, it is preferable to control the refractive index difference between the substrate and the functional layer within ±0.05. Alternatively, by forming a thin wall, the double-image view caused by reflection at the substrate-functional layer interface and reflection at the functional layer-air interface can be reduced.

[0107] As a hard coating applied to the surface of the light guide component, it is formed, for example, as follows: a coating liquid prepared by dissolving or dispersing a silicone-based curable resin, a curable resin containing organic polymer composite inorganic particles, urethane acrylate, epoxy acrylate, polyfunctional acrylate, or other acrylates, and a photopolymerization initiator or thermal polymerization initiator in an organic solvent is applied to the light guide component obtained from the resin composition of this embodiment using a conventionally known coating method, and then dried and cured by light or heat, thereby forming the coating.

[0108] In addition, to improve adhesion before applying the hard coating, a method can be used, for example, to form the hard coating after pre-setting an easy-to-adhere layer, primer layer, anchoring layer, etc., whose composition contains inorganic microparticles.

[0109] As an anti-glare layer applied to the surface of the light guide component, it is formed by making ink from particles such as silica, melamine resin, and acrylic resin, applying them to other functional layers using conventional coating methods, and then thermally or photocuring them.

[0110] As an antireflective layer applied to the surface of a light guide component (which may include functional layers such as hard coatings), examples include layers composed of inorganic thin films such as metal oxides, fluorides, silicides, borides, nitrides, and sulfides; layers formed by stacking single or multiple layers of resins with different refractive indices such as acrylic resins and fluororesins; and layers formed by stacking thin layers of composite microparticles containing inorganic and organic compounds.

[0111] A reflector, a semi-reflector, or a partial reflector (where the reflectivity to transmittance ratio is not 50:50, for example, a partial reflector with 15% transmittance and 85% reflectivity) can be applied to the surface of a light guide component (which may include a functional layer such as a hard coating). A reflector is defined as having a reflectivity higher than that of the substrate itself. Any suitable material can be used; for example, it can be constructed by coating a thin layer of metal (e.g., silver or aluminum) onto the light guide component. When coating a thin metal layer, since the metal absorbs light, it is preferable to form a reflector by depositing a thin-film dielectric coating on the surface of the light guide component. Alternatively, the methods of coating metal and coating dielectric can be combined. Without compromising the function of the reflector, a protective film such as a SiO2 film, SiO film, or MgF film can be added to the surface of the reflector.

[0112] Depending on the thickness and number of coating layers, the reflectivity and transmittance of light can be controlled. In the method of depositing dielectrics, it is also possible to design a system that reflects light of any wavelength only.

[0113] -size-

[0114] The size of the injection-molded light guide component in this embodiment is not particularly limited, but it is preferably the same size as that of vision correction glasses. (Referring to...) Figures 2A to 2C When illustrating the example light guide component, for example, the length in the x-axis direction of the injection-molded light guide component is preferably 10 mm or more and 80 mm or less, more preferably 20 mm or more and 60 mm or less, and even more preferably 35 mm or more and 55 mm or less. If the length in the x-axis direction is short, the image display element of the eyewear may come into contact with the face. Furthermore, at this distance, by utilizing the light guide component of the present invention, waveguides can be constructed while maintaining the polarized light state, suppressing the influence of the partial reflector of the present invention, where the reflectivity difference between P-polarized and S-polarized light is 10% or more, thus enabling a clear image to be presented to the observer.

[0115] In addition, the length of the injection-molded light guide component in the y-axis direction is preferably 10 mm or more and 80 mm or less, more preferably 10 mm or more and 50 mm or less, and even more preferably 25 mm or more and 45 mm or less.

[0116] When the light guide component of this embodiment is used in an AR head-mounted device, and visual recognition of the outside is performed via the output coupler, a correction prism can be provided on the opposite side to enable visual recognition without distortion through vision. In this case, as the adhesive used to bond the correction prism to the light guide component, it is preferable to control the difference between the refractive index of the light guide component and the refractive index of the adhesive within ±0.05. In this case, deformation caused by the difference in refractive index between the joint and the light guide component and the correction prism can be sufficiently suppressed. Furthermore, optical elements such as a linear polarizer, a linear polarizer plate, a half-wavelength phase difference plate, and a phase difference layer imparting a half-wavelength phase difference can be further provided on the outer side of the correction prism.

[0117] (Waveguide Section)

[0118] The injection-molded light guide component of this embodiment includes two opposing waveguide sections that guide light from an image display element through multiple repeated reflections. The two waveguide sections can be an eye-side waveguide section on the side of the observer's eye and an outer-side waveguide section on the outer side opposite to the eye-side waveguide section.

[0119] The shortest distance between the outer-side waveguide and the eye-side waveguide, i.e., the shortest distance between the waveguides on both sides, is preferably 0.6 mm or more and 25 mm or less, more preferably 1 mm or more and 20 mm or less, and even more preferably 1.2 mm or more and 20 mm or less. In other preferred embodiments, the shortest distance between the waveguides on both sides is preferably 1 mm or more and 8 mm or less. From a lightweight viewpoint, a thickness of 8 mm or less is preferred, as it is difficult to maintain the strength of the light guide component when the thickness is less than 0.6 mm. In addition, the thinner the wall, the more likely it is to warp due to molding deformation, thermal deformation, etc., in the case of a resin-made light guide component, making it difficult to reproduce a flat or precise curved surface. Therefore, the shortest distance between the waveguides on both sides is more preferably 1.2 mm or more and 15 mm or less, even more preferably 1.5 mm or more and 7 mm or less, and particularly preferably 2 mm or more and 6 mm or less.

[0120] In the injection-molded light guide component of this embodiment, the waveguide portion can be planar or curved. When the waveguide portion is curved, in order to avoid changes in the incident angle during waveguide operation, it is preferable that when the distance between the waveguide portions on both sides of the light guide component is set to the thickness t, the radius of curvature Rmm on the eye side is designed to be R+tmm, which is larger than the radius of curvature Rmm corresponding to the thickness t.

[0121] For the waveguide section, the projected length in the waveguide direction is preferably 10 mm or more. It should be noted that the waveguide direction refers to the direction in which light travels through the waveguide. Furthermore, the projected length in the waveguide direction is preferably 10 mm or more and 50 mm or less, more preferably 12 mm or more and 45 mm or less, and even more preferably 15 mm or more and 40 mm or less. By utilizing the light guide component of the present invention, waveguide operation can be performed while maintaining the polarization state, suppressing the influence of the partial reflector of the present invention, where the reflectivity difference between P-polarized light and S-polarized light is 10% or more, thus providing the observer with a clear image.

[0122] Furthermore, partial reflectors can be formed on both waveguide sections, transmitting a portion of the light and reflecting the remainder. The partial reflectors can be formed on only one of the two waveguide sections, or on both. That is, partial reflectors that transmit a portion of the light and reflect the remainder can be formed on a portion or all of the two sides of the waveguide sections. When the partial reflectors are formed on only one of the two waveguide sections, it is preferable to form the partial reflector that transmits a portion of the light and reflects the remainder on the outer waveguide section.

[0123] (Input Coupler)

[0124] Within the scope of not impairing the effects of the present invention, there are no particular limitations as long as the input coupler of this embodiment is a component capable of waveguided light within the light guide member. Examples of input couplers include surface-embossed diffraction gratings, volumetric holographic optical elements, liquid crystal diffraction gratings, prism-shaped components with an anti-reflective coating applied to a portion of their surface, partial reflectors applied to a portion of their surface, reflectors, polarization beam splitters (including reflective polarizing elements), and the like. By setting the incident angle at the waveguide portion to be above the critical angle of the substrate portion of the light guide member or the outermost layer of the light guide member during reflection, total internal reflection can be used to waveguide light, reducing light loss. Furthermore, when light is incident on the waveguide portion at an incident angle less than the critical angle, waveguides independent of the critical angle can be achieved using the aforementioned optical elements or partial reflectors or reflectors. In particular, from the perspective of improving light utilization efficiency by blocking a portion of the light, it is preferable to use an optical element with polarization selectivity capable of maintaining the polarization state in the input coupler.

[0125] Here, polarization selectivity means that the polarization state of the light (the wavelength region used) incident on the aforementioned optical element has a difference of more than 5% in any of the diffraction efficiency, transmittance, or reflectance of either the S-wave or the P-wave relative to the other.

[0126] (Output Coupler)

[0127] The output coupler in this embodiment is not particularly limited as long as it is a component capable of waveguided light within the light guide member without impairing the effects of the present invention. Examples of output couplers include surface-embossed diffraction gratings, volumetric holographic optical elements, liquid crystal diffraction gratings, prism-shaped components with an anti-reflective coating applied to a portion of their surface, partial reflectors applied to a portion of their surface, reflectors, polarization beam splitters (including reflective polarizing elements), and the like. Furthermore, the output coupler can be configured to allow part or all of the waveguided light to reach the observer's eye (viewpoint) using refraction, diffraction, or reflection. The shape of the output coupler is not limited to a plane; it can simultaneously function as a curved surface, a convex lens, a concave lens, and a freeform surface. By employing such a freeform surface, a retinal direct scanning optical system can be constructed. It should be noted that, particularly for purposes such as improving light utilization efficiency and providing the function of blocking a portion of the light, it is preferable to use an optical element with polarization selectivity capable of maintaining the polarization state in the output coupler.

[0128] In addition, the output coupler preferably has a partial reflector that transmits a portion of the light and reflects the remaining portion of the light.

[0129] [Characteristics of Injection Molded Light Guide Components]

[0130] -Polarization maintaining characteristics-

[0131] The polarization retention characteristics of the injection-molded light guide component in this embodiment can be evaluated by the following method.

[0132] As a specific indicator, when first polarized light, parallel to the optical axis of the light guide component, is incident, the light intensity (Tp) obtained by a power meter is used as a reference, based on the ratio (Tp / Tc) of the light intensity obtained by the power meter when the polarized light is transmitted through a polarizing plate positioned in front of the light extraction section. This polarization is achieved by rotating the polarizing plate 90 degrees in front of the light emission section and positioning it to block the first polarized light. In the case of multiple viewpoints, such as... Figure 3 As shown, power meters are placed at multiple locations to obtain the total amount of light.

[0133] The preferred ratio (Tp / Tc) for each wavelength is explained below. This ratio (Tp / Tc) varies depending on the magnitude of the ratio (Rs / Rp) of the reflectivity Rs of S-polarized light to the reflectivity Rp of P-polarized light of the partial reflector. Therefore, it is standardized as a value obtained by dividing by the ratio (Rs / Rp) and used as an indicator. It should be noted that when there are multiple reflectivity designs for the partial reflectors, the value is obtained as the ratio (Rs / Rp) of the surface with the largest ratio (Rs / Rp) of polarized reflectivity (Tp / Tc).

[0134] When using a blue laser that emits light with a dominant wavelength of 450 nm, (Tp / Tc) / (Rs / Rp) (450 nm) is preferably 6 or more. (Tp / Tc) / (Rs / Rp) (450 nm) is more preferably 12 or more, further preferably 18 or more, and particularly preferably 30 or more.

[0135] Furthermore, when the incident blue laser light, which is polarized along an axis orthogonal to the incident plane including the incident light and the reflected light, is incident on the light guide member, the ratio (Tp / Tc) / (Rs / Rp) (450nm) is preferably 7 or more, more preferably 10 or more, even more preferably 25 or more, and particularly preferably 40 or more.

[0136] When the polarized light of the incident blue laser, which is a P-polarized light vibrating within the incident plane including the incident light and the reflected light, is incident on the light guide component, (Tp / Tc) / (Rs / Rp) (450nm) is preferably 5 or more, more preferably 7 or more, further preferably 10 or more, and particularly preferably 15 or more.

[0137] When using a green laser that emits light with a dominant wavelength of 530 nm, (Tp / Tc) / (Rs / Rp) (530 nm) is preferably 10 or more. (Tp / Tc) / (Rs / Rp) (530 nm) is more preferably 15 or more, more preferably 20 or more, even more preferably 30 or more, and particularly preferably 40 or more.

[0138] Furthermore, when the polarized light from the incident green laser, which vibrates along an axis orthogonal to the incident plane including the incident light and the reflected light, is incident on the light guide component, the ratio (Tp / Tc) / (Rs / Rp) (530nm) is preferably 10 or more, more preferably 50 or more, even more preferably 100 or more, and particularly preferably 300 or more.

[0139] When the polarized light from the incident green laser, which vibrates on the incident surface including the incident light and the reflected light, is incident on the light guide component, the ratio (Tp / Tc) / (Rs / Rp) (530nm) is preferably 5 or more, more preferably 10 or more, even more preferably 20 or more, and particularly preferably 40 or more.

[0140] When using a red laser that emits light with a dominant wavelength of 630 nm, (Tp / Tc) / (Rs / Rp) (630 nm) is preferably 10 or more. (Tp / Tc) / (Rs / Rp) (630 nm) is more preferably 15 or more, further preferably 20 or more, and particularly preferably 25 or more.

[0141] Furthermore, when the incident red laser light, which is polarized along an axis orthogonal to the incident plane including the incident light and the reflected light, is incident on the light guide member, the ratio (Tp / Tc) / (Rs / Rp) (630nm) is preferably 10 or more, more preferably 50 or more, even more preferably 100 or more, and particularly preferably 150 or more.

[0142] When the polarized light from the incident red laser, which vibrates along an axis orthogonal to the incident plane including the incident light and the reflected light, is incident on the light guide component, the ratio (Tp / Tc) / (Rs / Rp) (630nm) is preferably 5 or more, more preferably 7 or more, even more preferably 10 or more, and particularly preferably 20 or more.

[0143] Thus, by fabricating a light guide component with a high (Tp / Tc) ratio, it is possible to display clear images without uneven brightness, uneven color, or rainbow patterns. A light guide component with a high (Tp / Tc) ratio can be obtained by using a resin composition with excellent low birefringence properties, described later, and by injection molding as described in this invention.

[0144] -Difference in reflectivity between P-polarized and S-polarized light from some mirrors-

[0145] As one embodiment of the present invention, by using a light guide component with high polarization retention performance, for example, when a partial reflector with high reflectivity for S-polarized light is used in the waveguide and / or output coupler, by using a polarizing light source element for the incident image, the image light of S-polarized light is incident on the reflective surface of the light guide component, thereby improving light utilization efficiency.

[0146] At this time, the ratio (Rs / Rp) of the reflectivity Rs of the first polarized light (S-polarized light) and the reflectivity Rp of the second polarized light (P-polarized light) orthogonal to the first polarized light at an incident angle of 30° in the partial mirror formed in the waveguide and / or output coupler is preferably 1.2 or more, more preferably 1.4 or more, more preferably 1.8 or more, and particularly preferably 3.0 or more. On the other hand, if the ratio (Rs / Rp) is 9.0 or more, the sealing performance of the mirror deteriorates, which is not preferred. Therefore, the ratio (Rs / Rp) is preferably less than 9.0.

[0147] Furthermore, for partial reflectors, when reflecting light using a partial reflector at an incident angle of 30°, the difference in reflectivity between the first polarized light (S-polarized) and the P-polarized light (a second polarized light orthogonal to the first polarized light) is preferably 10% or more, more preferably 15% or more. Even more preferably, it is 20% or more, and more preferably 30% or more. However, if the difference in reflectivity is 40% or more, the sealing performance of the reflector deteriorates, which is not preferred; therefore, it is preferable to have a difference of less than 40%.

[0148] In a preferred embodiment of the present invention, one of the two waveguide portions is an outer side waveguide portion. The outer side waveguide portion is formed with a partial reflector that transmits a portion of the light and reflects the remaining portion of the light. For the partial reflector, when the partial reflector is used for reflection at an incident angle of 30°, the difference between the reflectivity of the first polarized light as S-polarized light and the P-polarized light as a second polarized light orthogonal to the first polarized light is 10% or more.

[0149] In another preferred embodiment, the output coupler is formed with a partial reflector that transmits a portion of the light and reflects the remaining portion of the light. For the partial reflector, when the partial reflector is used for reflection at an incident angle of 30°, the difference between the reflectivity of the first polarized light (S-polarized light) and the P-polarized light (P-polarized light) (orthogonal to the first polarized light) is 10% or more.

[0150] It should be noted that when the output coupler is configured with a single segment, i.e., when only one column of viewpoints is formed in the X-axis direction (multiple viewpoints are possible in the Y-axis direction), if a mirror with high S-polarization reflectivity is used in the light extraction section, light cannot be extracted from the eye side. Therefore, it is preferable to use mirrors with low S-polarization and P-polarization reflectivity only in the light extraction section, or in both the eye-side waveguide section and the light extraction section. Furthermore, during eye-side extraction, the light is often incident perpendicularly to the light extraction section. Therefore, a mirror with appropriate reflectivity at the incident angle when the waveguide is in place is preferable, but it is also preferable to use a partially reflective mirror with low reflectivity at an incident angle of 0° when extracting light.

[0151] Furthermore, in the case of a configuration with multiple output couplers and a plurality of viewpoints, the configuration is not limited to this. A mirror with a higher reflectivity for S-polarized light than for P-polarized light can be used in the eye-side waveguide and light extraction section. In this case, it is preferable to appropriately adjust the reflectivity of the output coupler and the reflectivity of the light extraction section to ensure that the amount of light at each viewpoint is equal.

[0152] When the surface of the waveguide, including the incident and reflecting surfaces, is horizontal relative to the ground, S-polarized light perpendicular to the incident / reflecting surfaces of the waveguide (along...) Figure 4 The polarized light vibrating along the Y-axis is P-polarized light in the reflection of light on the ground (in...). Figure 5 (Polarized light vibrating in the XY plane). Therefore, with the aim of reducing reflected light from objects and water surfaces, and to block S-polarized light vibrating horizontally on the ground (P-polarized light for the incident / reflecting surface of the waveguide), by sequentially setting the polarizing plate that blocks the S-polarized light on the ground into a straight line connecting the viewpoint (i.e., the observer's eyeball), the output coupler, and the external connection, it is possible to give it the function of polarized sunglasses (see [reference]). Figure 6 ).

[0153] In addition to linear polarizers, half-wavelength elements or phase difference layers imparting a half-wavelength phase difference can also be used. In this case, by adjusting the reflectivity characteristics of partial reflectors, partial reflectors with high reflectivity for the waveguide section are used in the output coupler and external waveguide section. An image display element emitting S-polarized light (for the waveguide section) exhibits high transmittance for light incident from the outside via the linear polarizer and half-wavelength element (P-polarized light for the waveguide section's incident / reflection surface). Furthermore, this design enables high reflectivity for image light display within a waveguide component (see reference). Figure 7 ).

[0154] As a phase difference layer that imparts a phase difference of 1 / 2 wavelength, it is possible to use thin films that align and cure liquid crystals at a specified angle.

[0155] For the injection-molded light guide component of this embodiment, in the reflection at the waveguide section, first polarized light with a wavelength of 500-600 nm (S-polarized light) is incident from the light incident section. After the light is waveguided by the waveguide section, when the light is extracted from the light emitting section via the output coupler, the ratio (Tp / Tc) of the transmittance Tp extracted by the polarizing plate arranged with the axis of the first polarization aligned with the transmission axis and the transmittance Tc extracted by the polarizing plate arranged with the axis of the first polarization orthogonal to the transmission axis, divided by the ratio (Rs / Rp) of the reflectance Rs of the S-polarized light and the reflectance Rp of the P-polarized light of the partial reflector, is preferably 5 or more. Furthermore, this ratio (Tp / Tc) is preferably 10 or more, more preferably 15 or more, and even more preferably 20 or more. It should be noted that when some reflectors have multiple reflectivity designs, the value is obtained by dividing (Tp / Tc) by the ratio (Rs / Rp) of the surface with the largest polarization reflectivity (Rs / Rp).

[0156] -Evaluation in Image Observation-

[0157] The light guide component of this embodiment can be evaluated by the method described in the embodiments described later.

[0158] As an evaluation in image observation, it is preferable to observe an image without uneven brightness, uneven color, rainbow patterns, or double images. By using the preferred light guide component in the present invention described later, it is possible to display images without uneven brightness, uneven color, rainbow patterns, or double images.

[0159] -Phase difference within the effective region-

[0160] For the light guide component in this embodiment, the average absolute value of the phase difference within the effective area when light passes through the waveguide portions on both sides in a vertical direction, i.e., the in-plane phase difference within the effective area of ​​the waveguide portion for waveguided light, is 20 nm or less, preferably 10 nm or less, more preferably 5 nm or less, and even more preferably 3 nm or less. By using a light guide component whose average absolute value of the phase difference within the effective area is within the range described above, brightness non-uniformity, color non-uniformity, and rainbow patterns are suppressed. In addition, in the case of a long optical path, ghosting (image overlap) is suppressed, enabling visual recognition of clear and high-resolution images.

[0161] Here, the effective area of ​​the light guide component refers to the area of ​​image light transmission (including the waveguide) that an observer wearing the head-mounted display can visually recognize when their eyes are within the designed eye movement range, after the light guide component is assembled into the frame of the head-mounted display. This is appropriately defined by the optical designer.

[0162] Therefore, products with protrusions or fitting mechanisms for assembly into the frame must have these parts removed. In the absence of a clearly defined effective area, the area is considered to include at least 80% of the projected area on the object surface, excluding the areas with protrusions and fitting mechanisms. The projected area refers to the area of ​​all or part of the waveguide portion projected onto a horizontal plane when a parallel ray parallel to the direction of gravity is irradiated from a point at infinity vertically above the light guide component, with the object surface being inspected as the upper surface (i.e., the parallel projected area). The phase difference within the effective area of ​​the light guide component can be specifically measured using the method described in the embodiments described later.

[0163] The method for obtaining the light guide component with the effective area described above can achieve an in-plane phase difference within the aforementioned range by applying the preferred resin composition and preferred molding conditions described later. Additionally, methods such as removing the gate and its surrounding area with high birefringence from the light guide component, or manufacturing it using a molded body formed by curing monomers flowing into the mold via photocuring or thermocuring, are also possible. However, methods involving removing the gate and its surrounding area result in significant material loss and reduced adjustment range during optical system assembly, making them less desirable. Furthermore, methods for manufacturing light guide components via curing reactions suffer from issues with the length of the cycle time required to obtain a light guide component, making it difficult to obtain a cured product without residual strain. Therefore, it is preferable to obtain the light guide component via injection molding.

[0164] -surface accuracy-

[0165] For the light guide component in this embodiment, it is necessary to accurately reproduce the specified surface shape of the optical design. When the surface shape deviates from the design, aberrations such as spherical aberration and astigmatism occur, causing problems in the displayed image, such as image distortion, overall image blurring, and local image blurring.

[0166] The preferred surface accuracy can be expressed as the PV value, which represents the difference between the maximum and minimum values ​​of the deviation from the designed shape. For the waveguide sections on both sides, the PV value in the effective area for waveguided light is preferably less than 15.0 μm. Furthermore, the PV value is more preferably less than 10.0 μm, even more preferably less than 5.0 μm, and particularly preferably less than 3.0 μm.

[0167] Furthermore, the surface shape is not limited to a plane; it can also be a concave curved surface, a convex curved surface, a spherical surface, a freeform surface, or other shapes. Regardless of the type of curved surface, by employing the preferred materials and molding methods shown in this invention, a light guide component with excellent surface accuracy can be obtained.

[0168] In a preferred embodiment of the present invention, the shortest distance between the waveguide portions on both sides is 0.6 mm or more and 25 mm or less, the projected length of the waveguide component in the waveguide direction is 10 mm or more and 50 mm or less, and the PV in the effective area for waveguide of light on both sides is 10.0 μm or less.

[0169] -Glass transition temperature-

[0170] The glass transition temperature (Tg) of the light guide component in this embodiment is preferably 115°C to 150°C.

[0171] A glass transition temperature (Tg) of 115°C or higher is preferred for ensuring heat resistance to heat generated by electronic devices such as head-mounted displays. Furthermore, if the heat resistance temperature is low, the dimensional changes at high temperatures become larger. Additionally, when optical films such as polarizing films are bonded to the light guide component, peeling may occur due to differences in dimensional changes. Conversely, a high heat resistance temperature is also preferred from the viewpoint of suppressing photoelastic birefringence caused by tension at the bonding interface with the optical film. A glass transition temperature (Tg) of 120°C or higher is more preferred, further preferred to be 125°C or higher, and most preferably 130°C or higher.

[0172] To reduce the birefringence of the resin lens, the mold temperature during the injection molding process (described later) needs to be maintained in a high-temperature range close to the glass transition temperature. Furthermore, when removing the resin light guide component, the cooling time needs to be extended to suppress deformation such as shrinkage marks. Therefore, in addition to the increased cycle time, the rapid cooling due to the temperature difference with room temperature can easily leave residual deformation within the resin light guide component. Therefore, from the viewpoint of sufficiently reducing the birefringence of the light guide component, in this embodiment, a glass transition temperature greater than 150°C is not preferred.

[0173] On the other hand, when the glass transition temperature (Tg) is below 150°C, melting processing under extreme high-temperature conditions can be avoided, thermal decomposition of resins and the like can be suppressed, and good products can be obtained. From the viewpoint of further obtaining the above-mentioned effects, the glass transition temperature (Tg) is preferably below 145°C, and more preferably below 140°C.

[0174] It should be noted that the glass transition temperature (Tg) can be determined according to JIS-K7121. Specifically, it can be obtained using the method described in the examples below.

[0175] The glass transition temperature of the aforementioned light guide component can be adjusted to the above range, for example, in the present invention described later, by making the substrate portion from a preferred resin composition. The glass transition temperature can be increased by having a ring structure in the main chain of the resin composition.

[0176] -Photoelastic coefficient CR-

[0177] In this embodiment, the absolute value of the photoelastic coefficient CR of the light guide component, |CR|, is 10.0 × 10⁻⁶. -12 Pa -1 The preferred value is 5.0 × 10⁻⁶. -12 Pa -1 Hereinafter, 3.0 × 10 is preferred. -12 Pa -1 Hereinafter, 1.0 × 10 is further preferred. -12 Pa -1 the following.

[0178] The photoelastic coefficient is described in various documents (e.g., see *General Chemistry* (No. 39, 1998, published by the Society's Publishing Center)) and is defined by the following equations (ia) and (ib). It can be seen that the closer the absolute value of the photoelastic coefficient CR is to zero, the smaller the change in birefringence caused by external force.

[0179] |CR|=|Δn| / σR (ia)

[0180] |Δn|=|nx-ny| (ib)

[0181] (In the formula, CR represents the photoelastic coefficient, σR represents the tensile stress, |Δn| represents the absolute value of birefringence, nx represents the refractive index in the tensile direction, and ny represents the refractive index in the direction perpendicular to the tensile direction in the plane.)

[0182] If the absolute value of the photoelastic coefficient CR of the light guide component in this embodiment, |CR|, is 10.0 × 10⁻⁶. -12 Pa -1 The following measures reduce birefringence caused by internal deformation during the molding of the light guide component. Furthermore, the stress birefringence caused by stress generated when fixing and bonding the light guide component to the lens barrel and fixture is sufficiently small. In optical devices utilizing polarized light, resin lenses that suppress ghosting, reduce contrast degradation, and produce clear images can be obtained. On the other hand, if the absolute value of the photoelastic coefficient CR, |CR|, is large, birefringence occurs, resulting in uneven brightness, uneven color, and rainbow patterns as described above, which is therefore undesirable.

[0183] It should be noted that after the light guide component is shredded, a vacuum compression molding machine is used to form a pressed film, thereby enabling the measurement of the photoelastic coefficient CR. Specifically, it can be determined using the method described in the embodiments below.

[0184] The absolute value of the photoelastic coefficient of the aforementioned light guide component can be adjusted to the aforementioned range, for example, in this embodiment described later, by making the substrate portion of the light guide component from a preferred resin composition. Preferably, the copolymerization ratio of monomers with a positive photoelastic coefficient to monomers with a negative photoelastic coefficient in the homopolymer is adjusted to an appropriate range. In the case of cyclic olefin copolymers, by adjusting the copolymerization ratio of structural units from α-olefins to structural units from cyclic olefins to an appropriate range, a cyclic olefin copolymer resin composition with a small absolute value of the photoelastic coefficient can be obtained. Furthermore, stress deformation can be mitigated by annealing, but heat treatment is required in the range of -35°C to near the glass transition temperature of the resin to sufficiently mitigate stress. During this process, the surface shape changes, resulting in focal deviation, etc., which is therefore not preferred. Therefore, it is preferable to mold the light guide component from a resin composition with a small photoelastic coefficient.

[0185] -Light transmittance-

[0186] In this embodiment, the light guide component allows light to pass through the waveguide sections on both sides in a manner that transmits vertically through both surfaces, enabling measurement using a spectrophotometer with a D65 light source and a 2° field of view. Regarding light transmittance, the ratio (T450 / T680) of the transmittance at a wavelength of 450 nm to the transmittance at a wavelength of 680 nm is preferably 0.95 to 1.03, more preferably 0.97 to 1.01, and even more preferably 0.98 to 1.00. If the ratio (T450 / T680) is within the above range, an image with good tonal quality can be obtained.

[0187] It should be noted that, specifically, the light transmittance can be measured using the methods described in the embodiments described later.

[0188] <Resin Composition>

[0189] In the light guide component of this embodiment, the substrate portion is composed of a resin composition. More specifically, the substrate portion is composed of a thermoplastic resin composition having a cyclic structure in the main chain or side chains. As this resin composition, it is not particularly limited as long as it contains a thermoplastic resin with both low birefringence and heat resistance properties to prevent rainbow patterns from occurring due to differences in the polarization reflectivity of some reflectors. As a resin capable of achieving highly low birefringence properties, it is preferable to contain a methacrylic resin. That is, the thermoplastic resin composition having a cyclic structure in the main chain or side chains is preferably a methacrylic resin composition, specifically a methacrylic resin composition having a cyclic structure in the main chain or side chains. Furthermore, as a thermoplastic resin composition having a cyclic structure in the main chain or side chains, a cyclic olefin copolymer resin composition containing a cyclic olefin copolymer is also preferred. In summary, it is preferable that the thermoplastic resin composition having a cyclic structure in the main chain or side chains contains a methacrylic resin or a cyclic olefin copolymer having a cyclic structure in the main chain or side chains; that is, it is preferable that it contains a methacrylic resin composition or a cyclic olefin copolymer resin composition containing a methacrylic resin having a cyclic structure in the main chain or side chains.

[0190] (Methacrylic resin)

[0191] As a methacrylic resin, to ensure sufficient heat resistance, a methacrylic resin comprising structural units (X) having a ring structure in the main chain and structural units derived from methacrylate monomers is particularly preferred. By comprising a methacrylic resin, and especially a methacrylic resin comprising structural units (X) having a ring structure in the main chain and methacrylate monomer units, it is possible to obtain a light guide component with high heat resistance, sufficiently small in-plane phase difference in the effective area, and sufficiently small photoelasticity.

[0192] [Methacrylic resins with a ring structure in the main chain]

[0193] The following describes the structural units of a methacrylate resin having a structural unit (X) with a ring structure in the main chain and structural units derived from methacrylate monomers.

[0194] -Structural units derived from methacrylate monomers-

[0195] Structural units derived from methacrylate monomers can be, for example, from monomers selected from the following classes of methacrylates. Examples of methacrylates include methyl methacrylate, ethyl methacrylate, n-propyl methacrylate, isopropyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, tert-butyl methacrylate, 2-ethylhexyl methacrylate, cyclopentyl methacrylate, cyclohexyl methacrylate, cyclooctyl methacrylate, tricyclodecyl methacrylate, dicyclooctyl methacrylate, tricyclododecyl methacrylate, isobornyl methacrylate, phenyl methacrylate, benzyl methacrylate, 1-phenylethyl methacrylate, 2-phenoxyethyl methacrylate, 3-phenylpropyl methacrylate, and 2,4,6-tribromophenyl methacrylate.

[0196] These monomers are sometimes used alone, and sometimes two or more are used together.

[0197] From the perspective of excellent transparency and weather resistance, structural units derived from methyl methacrylate and benzyl methacrylate are preferred as structural units derived from methacrylate monomers.

[0198] The structural units derived from methacrylate monomers may contain one or more types.

[0199] By appropriately adjusting the ratio of structural units (X) with ring structures in the main chain to structural units derived from methacrylate monomers, a light guide component with reduced birefringence caused by orientation and residual stress during molding and an absolute value of in-plane phase difference of 20 nm or less in the effective region can be obtained as the methacrylate resin included in the resin composition. Furthermore, by appropriately adjusting the above ratio, sufficient heat resistance can be imparted to the methacrylate resin. From these viewpoints, the content of structural units derived from methacrylate monomers is set to 100% by mass of methacrylate resin, preferably 50–97% by mass, more preferably 55–97% by mass, further preferably 55–95% by mass, even more preferably 60–93% by mass, and particularly preferably 60–90% by mass.

[0200] It should be noted that the content of structural units derived from methacrylate monomers can be determined by... 1H-NMR measurements and 13 The determination was obtained by C-NMR measurements. 1 H-NMR measurements and 13 C-NMR determination, for example, can be performed using deuterated chloroform (CDCl3) or deuterated dimethyl sulfoxide (DMSO-d6) as the determination solvent, and can be carried out at a determination temperature of 40°C.

[0201] -In the main chain, there is a structural unit (X) with a ring structure-

[0202] The following describes the structural unit (X) with a ring structure in the main chain.

[0203] The structural unit (X) having a ring structure in the main chain preferably comprises at least one structural unit selected from the group consisting of structural units from N-substituted maleimide monomers, glutarimide-based structural units, and lactone ring structural units. More preferably, it comprises only at least one structural unit selected from the group consisting of structural units from N-substituted maleimide monomers, glutarimide-based structural units, and lactone ring structural units. The structural unit (X) having a ring structure in the main chain can be one type or a combination of more than one type.

[0204] In other preferred embodiments, the methacrylic resin preferably has at least one structural unit selected from the group consisting of structural units derived from N-substituted maleimide monomers, glutarimide structural units, lactone ring structural units, and aromatic ring hydrogenated structural units. In cases where the methacrylic resin incorporates a ring structure into the main chain via a cyclization process, carboxylic acid side chains may remain, becoming a major cause of very high water absorption. This negatively impacts the adhesion of antireflective coatings, mirror coatings, and the adhesion to reflective polarizing elements. Therefore, structural units derived from N-substituted maleimide monomers or methacrylic resins having aromatic ring hydrogenated structural units are more preferred. In particular, from the viewpoint of easily controlling optical properties such as the photoelasticity coefficient without mixing with other thermoplastic resins, structural units derived from N-substituted maleimide monomers are especially preferred.

[0205] Furthermore, from the viewpoint that a ring structure that can improve heat resistance and control low birefringence can be obtained without adding acids or bases that would cause suppression of adhesion of reflective polarizing elements, an N-substituted maleimide monomer unit structure is particularly preferred.

[0206] --Structural units derived from N-substituted maleimide monomers--

[0207] Then, the structural units from N-substituted maleimide monomers are described.

[0208] The structural unit from the N-substituted maleimide monomer can be at least one structural unit selected from the group consisting of structural units represented by the following general formula (1) and structural units represented by the following general formula (2), preferably formed by both structural units represented by the following general formula (1) and the following general formula (2).

[0209] (1)

[0210] In general formula (1), R 1 R represents any one of arylalkyl groups having 7 to 14 carbon atoms and aryl groups having 6 to 14 carbon atoms. 2 and R 3 Each of the following can be independently represented: hydrogen atom, oxygen atom, sulfur atom, alkyl group having 1 to 12 carbon atoms, and aryl group having 6 to 14 carbon atoms.

[0211] In addition, in general formula (1), in R 2 Or R 3 In the case of aryl, R 2 Or R 3 It may or may not contain halogen atoms as substituents.

[0212] In addition, in general formula (1), R 1 It may or may not be substituted by halogen atoms, alkyl groups with 1 to 6 carbon atoms, alkoxy groups with 1 to 6 carbon atoms, nitro groups, benzyl groups, etc.

[0213] (2)

[0214] In general formula (2), R 4 R represents any one of hydrogen atoms, cycloalkyl groups having 3 to 12 carbon atoms, and alkyl groups having 1 to 12 carbon atoms. 5 and R 6 Each of the following can be independently represented: hydrogen atom, oxygen atom, sulfur atom, alkyl group having 1 to 12 carbon atoms, and aryl group having 6 to 14 carbon atoms.

[0215] The following are specific examples of monomers that form structural units represented by general formulas (1) and (2).

[0216] As monomers forming structural units represented by general formula (1) (N-arylmaleimides, N-aromatic substituted maleimides, etc.), examples include N-phenylmaleimide, N-benzylmaleimide, N-(2-chlorophenyl)maleimide, N-(4-chlorophenyl)maleimide, N-(4-bromophenyl)maleimide, N-(2-methylphenyl)maleimide, N-(2,6-dimethylphenyl)maleimide, N-(2-ethylphenyl)maleimide, N-(2-methoxyphenyl)maleimide, N-(2-nitrophenyl)maleimide, N-(2,4,6-trimethylphenyl)maleimide, N-(4-benzylphenyl)maleimide, N-(2,4,6-tribromophenyl)maleimide, N-naphthylmaleimide, N-anthraylmaleimide, 3-methyl-1-phenyl-1H-pyrrole-2,5-dione, 3,4-dimethyl-1-phenyl-1H-pyrrole-2,5-dione, 1,3-diphenyl-1H-pyrrole-2,5-dione, 1,3,4-triphenyl-1H-pyrrole-2,5-dione, etc.

[0217] Among these monomers, N-phenylmaleimide and N-benzylmaleimide are preferred from the viewpoint that the resulting methacrylic resin has excellent heat resistance and optical properties such as birefringence.

[0218] These monomers are sometimes used alone, and sometimes two or more are used together.

[0219] Examples of monomers that form the structural unit represented by general formula (2) include, for example, N-methylmaleimide, N-ethylmaleimide, N-n-propylmaleimide, N-isopropylmaleimide, N-n-butylmaleimide, N-isobutylmaleimide, N-sec-butylmaleimide, N-tert-butylmaleimide, N-n-pentylmaleimide, N-n-hexylmaleimide, and N-n-heptylmaleimide. N-octylmaleimide, N-laurylmaleimide, N-cyclopentylmaleimide, N-cyclohexylmaleimide, 1-cyclohexyl-3-methyl-1H-pyrrole-2,5-dione, 1-cyclohexyl-3,4-dimethyl-1H-pyrrole-2,5-dione, 1-cyclohexyl-3-phenyl-1H-pyrrole-2,5-dione, 1-cyclohexyl-3,4-diphenyl-1H-pyrrole-2,5-dione, etc.

[0220] Among these monomers, from the viewpoint of excellent weather resistance of methacrylic resins, N-methylmaleimide, N-ethylmaleimide, N-isopropylmaleimide, and N-cyclohexylmaleimide are preferred. Since the demand for excellent low moisture absorption in optical materials has been increasing in recent years, N-cyclohexylmaleimide with alicyclic groups on the side chain is particularly preferred.

[0221] These monomers can be used individually or in combination of two or more.

[0222] In the methacrylic resin of this embodiment, from the perspective of being able to exhibit highly controlled birefringence characteristics, it is particularly preferred to use both the structural unit represented by general formula (1) and the structural unit represented by general formula (2).

[0223] The molar ratio (X1 / X2) of the content (X1) of the structural unit represented by formula (1) to the content (X2) of the structural unit represented by general formula (2) is preferably greater than 0 and less than 15, more preferably greater than 0 and less than 10.

[0224] When the molar ratio (X1 / X2) is within this range, the light guide component of this embodiment maintains transparency and does not yellow. In addition, it exhibits good heat resistance and good photoelastic properties without compromising environmental resistance.

[0225] The content of structural units from N-substituted maleimide monomers is set to 100% by mass for methacrylic resins, preferably in the range of 5 to 40% by mass, and more preferably in the range of 5 to 35% by mass.

[0226] Within this range, methacrylic resins achieve more significant improvements in heat resistance. Furthermore, they exhibit even better improvements in weather resistance, low water absorption, and optical properties. It should be noted that setting the content of structural units from N-substituted maleimide monomers to 40% by mass or less is effective in preventing a decrease in the reactivity of monomer components during polymerization and a decline in the physical properties of methacrylic resins due to an increase in the amount of unreacted and residual monomers.

[0227] Furthermore, by appropriately adjusting the content of structural units from the N-substituted maleimide monomer within this range, it is possible to obtain a light guide component with reduced birefringence caused by orientation and residual stress during molding, and an absolute value of the in-plane phase difference within the effective area of ​​20 nm or less. The optimal content of structural units from the N-substituted maleimide monomer varies depending on the type of N-substituted maleimide. For example, when methyl methacrylate is used as the methacrylate monomer and N-phenylmaleimide and N-cyclohexylmaleimide are used as the N-substituted maleimide monomers, it is preferable to adjust the content within the range of 79–83% by mass of structural units from methyl methacrylate, 6–8% by mass of structural units from N-phenylmaleimide, and 11–13% by mass of structural units from N-cyclohexylmaleimide.

[0228] N-substituted maleimides leave behind acidic components such as maleic acid and fumaric acid as byproducts during the manufacturing process, but the amount of acidic components can be significantly reduced during the purification process. Furthermore, if stored in a high-temperature and high-humidity environment, hydrolysis and ring-opening will similarly generate maleic acid, fumaric acid, and other acidic components as byproducts. The formation of these acidic components can be suppressed by storing them at a low temperature in a dark place with controlled humidity. In addition, methacrylic resins with N-substituted maleimides in the main chain have the advantage of easily controlling the residual amounts of acidic and basic components without resorting to cyclization processes using acids or bases. Therefore, resins with low levels of acidic components can be obtained.

[0229] Without prejudice to the purpose of the invention, in the resin composition, the methacrylic resin having structural units from N-substituted maleimide monomers may contain structural units from other monomers capable of copolymerizing with structural units from methacrylate monomers and structural units from N-substituted maleimide monomers.

[0230] Examples of other monomers that can be copolymerized include aromatic vinyl monomers; unsaturated nitrile monomers; acrylates having cyclohexyl, benzyl, or alkyl groups having 1 to 18 carbon atoms; glycidyl compounds; and unsaturated carboxylic acids.

[0231] Examples of aromatic vinyl monomers include styrene, α-methylstyrene, and divinylbenzene.

[0232] Examples of unsaturated nitriles include acrylonitrile, methacrylonitrile, and ethyl acrylonitrile.

[0233] Examples of acrylates mentioned above include methyl acrylate, ethyl acrylate, propyl acrylate, isopropyl acrylate, and butyl acrylate.

[0234] Examples of glycidyl compounds mentioned above include glycidyl (meth)acrylate.

[0235] Examples of unsaturated carboxylic acids include acrylic acid, methacrylic acid, itaconic acid, maleic acid, fumaric acid, and their semi-esters or anhydrides.

[0236] The structural units derived from other copolymerizable monomers may have only one type or more types.

[0237] As for the content of these structural units from other monomers that can copolymerize, the methacrylic resin is set to 100% by mass, preferably 0 to 10% by mass, more preferably 0 to 9% by mass, and even more preferably 0 to 8% by mass.

[0238] If the content of structural units from other monomers is within this range, the molding processability and mechanical properties of the resin can be improved without compromising the original effect of introducing ring structures into the main chain, and therefore this is preferred.

[0239] It should be noted that the content of structural units from N-substituted maleimide monomers and the content of structural units from other monomers capable of copolymerization can be determined by... 1 H-NMR measurements and 13 The determination was obtained by C-NMR measurements. 1 H-NMR measurements and 13 C-NMR determination, for example, can be performed using deuterated chloroform (CDCl3) or deuterated dimethyl sulfoxide (DMSO-d6) as the determination solvent, and can be carried out at a determination temperature of 40°C.

[0240] --Glutarimide structural unit--

[0241] As a methacrylic resin having glutarimide structural units in the main chain, examples include methacrylic resins having glutarimide structural units as described in Japanese Patent Application Publication No. 2006-249202, Japanese Patent Application Publication No. 2007-009182, Japanese Patent Application Publication No. 2007-009191, Japanese Patent Application Publication No. 2011-186482, and Japanese Re-publication Patent No. 2012 / 114718, which can be formed by the methods described in the publications.

[0242] The glutarimide structural units constituting the methacrylic resin of this embodiment can be formed after resin polymerization.

[0243] Specifically, the glutarimide structural unit can be represented by the following general formula (3).

[0244] (3)

[0245] In the above general formula (3), it is preferred that R 7 and R 8 Each can be independently a hydrogen atom or a methyl group, R 9 It is any one of hydrogen atom, methyl, butyl, cyclohexyl, more preferably, R 7 For methyl, R 8 For hydrogen atoms, R 9 It is a methyl group.

[0246] Glutarimide structural units can contain only a single type or multiple types.

[0247] In methacrylic resins having glutarimide structural units, the content of glutarimide structural units is set to 100% by mass, preferably in the range of 3 to 70% by mass, and more preferably in the range of 3 to 60% by mass.

[0248] If the content of glutarimide structural units is within the above range, a resin with good molding processability, heat resistance, and optical properties can be obtained, and therefore it is preferred.

[0249] Furthermore, by appropriately adjusting the content of glutarimide-based structural units within this range, it is possible to obtain a light guide component with reduced birefringence caused by orientation and residual stress during molding, and an absolute value of the in-plane phase difference within the effective region of less than 20 nm. According to general formula (3), R... 7 ~R 9 The types of substituents and the optimal content of glutarimide structural units vary. For example, when R... 7 and R 8 It is a hydrogen atom and R 9 When the methyl group is used, if the content of the glutarimide structural unit is in the range of 3 to 10% by mass, a light guide component with reduced birefringence caused by orientation or residual stress during molding and an absolute value of in-plane phase difference of less than 20 nm in the effective area can be obtained.

[0250] It should be noted that the content of glutarimide structural units in methacrylic resins can be determined using the methods described in the aforementioned patent documents.

[0251] Depending on the requirements, methacrylic resins having glutarimide-based structural units may also contain aromatic vinyl units.

[0252] There are no particular limitations on the aromatic vinyl monomers; examples include styrene and α-methylstyrene, with styrene being preferred.

[0253] The content of aromatic vinyl units in methacrylic resins having glutarimide structural units is not particularly limited, but the content of methacrylic resins having glutarimide structural units is set to 100% by mass, preferably 0 to 20% by mass.

[0254] If the content of aromatic vinyl units is within the above range, it is preferred to have both heat resistance and excellent photoelastic properties.

[0255] For example, when a methyl methacrylate-styrene copolymer obtained by copolymerizing methyl methacrylate as a methacrylate monomer and styrene as an aromatic vinyl monomer is subjected to glutarimide treatment to obtain a resin, by adjusting the percentage of structural units from methyl methacrylate (25–90% by mass), structural units from styrene (5–15% by mass), and glutarimide structural units (5–70% by mass), it is possible to obtain a light guide component with reduced birefringence caused by orientation and residual stress during molding and an absolute value of in-plane phase difference of less than 20 nm in the effective area.

[0256] In addition, as another effect, by copolymerizing monomers with low water absorption such as styrene, the water absorption rate of the resulting methacrylic resin and the resin composition thereof can be reduced, thereby preventing the peeling of reflective polarizing elements after reliability testing in high humidity environments and suppressing the deterioration of lens surface accuracy.

[0257] --Lactone ring structural unit--

[0258] Methacrylic acid resins having lactone ring structural units in the main chain can be formed, for example, by the methods described in Japanese Patent Application Publication Nos. 2001-151814, 2004-168882, 2005-146084, 2006-96960, 2006-171464, 2007-63541, 2007-297620, and 2010-180305.

[0259] The lactone ring structural units constituting the methacrylic resin of this embodiment can be formed after resin polymerization.

[0260] As the lactone ring structural unit in this embodiment, a six-membered ring is preferred due to the excellent stability of the ring structure.

[0261] As a six-membered ring lactone ring structural unit, for example, the structure shown by the following general formula (4) is particularly preferred.

[0262] (4)

[0263] In the above general formula (4), R 10 R 11 and R 12 Organic residues consisting of hydrogen atoms or 1 to 20 carbon atoms, which are independent of each other.

[0264] Examples of organic residues include saturated aliphatic hydrocarbon groups (alkyl groups, etc.) with 1 to 20 carbon atoms, such as methyl, ethyl, and propyl; unsaturated aliphatic hydrocarbon groups (alkenyl groups, etc.) with 2 to 20 carbon atoms, such as vinyl and propenyl; aromatic hydrocarbon groups (aryl groups, etc.) with 6 to 20 carbon atoms, such as phenyl and naphthyl; and groups obtained by substituting one or more hydrogen atoms in these saturated aliphatic hydrocarbon groups, unsaturated aliphatic hydrocarbon groups, and aromatic hydrocarbon groups with at least one group selected from the group consisting of hydroxyl, carboxyl, ether, and ester groups.

[0265] The lactone ring structural unit can be formed, for example, by copolymerizing an acrylic monomer with hydroxyl groups with a methacrylate monomer such as methyl methacrylate, introducing hydroxyl and ester groups, or introducing hydroxyl and carboxyl groups into the molecular chain, and then undergoing de-alcoholization (esterification) or dehydration condensation (hereinafter also referred to as "cyclization condensation reaction") between these hydroxyl and ester groups or between hydroxyl and carboxyl groups.

[0266] Examples of acrylic monomers with hydroxyl groups used in polymerization include 2-(hydroxymethyl)acrylic acid, 2-(hydroxyethyl)acrylic acid, alkyl 2-(hydroxymethyl)acrylates (e.g., methyl 2-(hydroxymethyl)acrylate, ethyl 2-(hydroxymethyl)acrylate, isopropyl 2-(hydroxymethyl)acrylate, n-butyl 2-(hydroxymethyl)acrylate, tert-butyl 2-(hydroxymethyl)acrylate), and alkyl 2-(hydroxyethyl)acrylates. 2-(hydroxymethyl)acrylic acid and alkyl 2-(hydroxymethyl)acrylates, which are monomers having hydroxyalkyl groups, are preferred, and methyl 2-(hydroxymethyl)acrylate and ethyl 2-(hydroxymethyl)acrylates are particularly preferred.

[0267] The content of lactone ring structural units in methacrylic resins having lactone ring structural units in the main chain is preferably 5 to 40% by mass, more preferably 5 to 35% by mass, relative to 100% by mass of the methacrylic resin.

[0268] If the content of lactone ring structural units is within this range, it is possible to maintain molding processability while exhibiting the effects of improved solvent resistance and increased surface hardness, which are characteristic of introducing the ring structure. Furthermore, by appropriately adjusting the content of lactone ring structural units within this range, it is possible to obtain a light guide component that reduces birefringence caused by orientation or residual stress during molding and has an absolute value of less than 20 nm for the in-plane phase difference within the effective region.

[0269] It should be noted that the content of lactone ring structures in methacrylic resins can be determined using the methods described in the aforementioned patent documents.

[0270] Methacrylic resins with lactone ring structural units in the main chain can also have structural units from other monomers that can copolymerize with the structural units from methacrylate monomers and structural units from acrylic monomers having hydroxyl groups.

[0271] Other monomers capable of copolymerization include, for example, styrene, vinyltoluene, α-methylstyrene, α-hydroxymethylstyrene, α-hydroxyethylstyrene, acrylonitrile, methacrylonitrile, methyl allyl alcohol, ethylene, propylene, 4-methyl-1-pentene, vinyl acetate, 2-hydroxymethyl-1-butene, methyl vinyl ketone, N-vinylpyrrolidone, N-vinylcarbazole, and other monomers with polymerizable double bonds.

[0272] These other monomers (structural units) may have only one type or more than two types.

[0273] In particular, by copolymerizing low-absorbency monomers such as styrene, the water absorption rate of the resulting methacrylic resin and the resin composition thereof can be reduced.

[0274] The content of these structural units from other monomers that can copolymerize is preferably 0 to 20% by mass relative to 100% by mass of the methacrylic resin, more preferably less than 10% by mass from the viewpoint of weather resistance, and even more preferably less than 7% by mass.

[0275] The methacrylic resin in this embodiment may have only one of the structural units derived from other monomers capable of copolymerization, or it may have two or more of these structural units.

[0276] --Methacrylic resins containing aromatic ring hydrogenated structural units--

[0277] In addition, methacrylic resins containing aromatic ring hydrogenated structural units are preferred as methacrylic resins.

[0278] As a method for manufacturing methacrylic resins having aromatic ring hydrogenated structural units, a method is used to manufacture a nuclear hydrogenated polymer by hydrogenating a copolymer of an aromatic vinyl compound and a (meth)acrylate in the presence of a hydrogenation catalyst and a reaction solvent.

[0279] The following is a specific example of a method for manufacturing a methacrylic resin containing aromatic ring hydrogenated structural units, obtained by hydrogenating a copolymer of an aromatic vinyl compound and a (meth)acrylate.

[0280] Examples of aromatic vinyl compounds used in polymerization include styrene, α-methylstyrene, vinyltoluene, α-hydroxymethylstyrene, α-hydroxyethylstyrene, p-hydroxystyrene, alkoxystyrene, and chlorostyrene, but styrene is preferred. Furthermore, copolymerization of two or more aromatic vinyl compounds is also possible. In particular, the use of styrene with a substituent at the α-position improves the heat resistance of the resin, and is therefore preferred.

[0281] In the case of copolymers of aromatic vinyl compounds and (meth)acrylates, the composition of the copolymer's structural units is not necessarily consistent with the composition of the added monomers, but is determined by the amount of monomers actually entering the copolymer through the polymerization reaction. For the ratio of the copolymer's structural units, if the polymerization rate is 100%, it will be consistent with the composition ratio of the added monomers. However, in practice, most copolymers are manufactured with polymerization rates of 50-80%. More reactive monomers are more likely to enter the copolymer. Therefore, the composition of the added monomers will deviate from the composition of the copolymer's structural units, thus requiring appropriate adjustment of the added monomer composition ratio.

[0282] In the hydrogenation reaction of this invention, the molar ratio (A / B) of the structural unit of the copolymer of aromatic vinyl compound and (meth)acrylate used in the hydrogenation reaction is preferably 0.25 or more and 4.0 or less, where the structural unit (A molar) from the (meth)acrylate monomer is relative to the structural unit (B molar) from the aromatic vinyl compound monomer. If the molar ratio (A / B) is less than 0.25, the mechanical strength is sometimes poor, making it impractical. If the molar ratio (A / B) is greater than 4.0, there are fewer aromatic rings after hydrogenation, and therefore, the performance improvement effect, such as the increase in glass transition temperature, brought about by the hydrogenation reaction is sometimes insufficient.

[0283] In addition, without prejudice to the purpose of the present invention, methacrylic resins containing aromatic ring hydrogenated structural units may also contain structural units from other monomers that can copolymerize with the aromatic ring hydrogenated structural units.

[0284] The content of these structural units from other monomers that can copolymerize is preferably 0 to 20% by mass relative to 100% by mass of the methacrylic resin, more preferably less than 10% by mass from the viewpoint of weather resistance, and even more preferably less than 7% by mass.

[0285] The methacrylic resin in this embodiment may have only one of the structural units derived from other monomers capable of copolymerization, or it may have two or more of these structural units.

[0286] - Manufacturing method of methacrylic resins-

[0287] The following describes a method for manufacturing the methacrylic resin according to this embodiment.

[0288] --Method for manufacturing methacrylic resins containing structural units derived from N-substituted maleimide monomers--

[0289] As a method for manufacturing methacrylic resins (hereinafter, sometimes referred to as "maleimide copolymers") having structural units derived from N-substituted maleimide monomers on the main chain, any of the following polymerization methods can be cited: bulk polymerization, solution polymerization, suspension polymerization, precipitation polymerization, and emulsion polymerization. From the viewpoint of reducing the amount of residual monomers and impurities contained in the light guide component, suspension polymerization, bulk polymerization, and solution polymerization are preferred, and solution polymerization is more preferred.

[0290] As for the method of adding the polymerization initiator, there are no particular restrictions as long as it is added variably based on the residual monomer concentration in the polymerization solution rather than a fixed addition rate; it can be added continuously or intermittently. In the case of intermittent addition of the polymerization initiator, the amount added per unit time is not considered for the time during which no initiator is added.

[0291] In the manufacturing method of this embodiment, batch, semi-batch, and continuous polymerization can be used as polymerization forms. Here, batch polymerization refers to a process where the total amount of raw material is added to the reactor, the reaction begins and continues, and the product is recovered after the reaction is complete. Semi-batch polymerization refers to a process where either raw material input or product recovery is performed simultaneously during the reaction. Continuous polymerization refers to a process where both raw material input and product recovery are performed simultaneously during the reaction. In this embodiment, from the viewpoint of precisely controlling the copolymer composition, reducing the amount of residual N-substituted maleimide at the end of polymerization, and reducing byproducts related to hue and fluorescence, a so-called semi-batch polymerization method is preferred. This semi-batch polymerization method involves loading a portion of the monomer into the reactor before polymerization begins, initiating polymerization by adding a polymerization initiator, and then supplying the remaining monomer.

[0292] As the manufacturing method in this embodiment, a continuous process is preferred for the following reasons. When a polymerization reaction is carried out using a single fully mixed reactor, it has the advantage of reducing the difference in monomer composition between components with different molecular weights in the methacrylic resin. However, since a large amount of unreacted monomer remains after polymerization, it tends to have an adverse effect on the color tone. On the other hand, when using a plug flow reactor, the amount of unreacted monomer can be reduced. However, it tends to increase the difference in monomer composition between components with different molecular weights in the methacrylic resin. When multiple fully mixed reactors or a fully mixed reactor and a plug flow reactor are connected in series, the amount of unreacted monomer can also be reduced, but it tends to increase the difference in monomer composition between the components mentioned above.

[0293] In order to maintain the hue and transmittance of the light guide component obtained by using methacrylic resin and the composition thereof and to reduce the content of fluorescent luminescent material, it is preferable to set the total mass of unreacted N-substituted maleimide remaining after polymerization to be 1000 ppm or less relative to 100% of the polymerization solution at the end of polymerization, more preferably 10 ppm or more and 500 ppm or less.

[0294] Furthermore, when N-aryl maleimides such as N-phenylmaleimide are used as N-substituted maleimides, the total mass of unreacted N-aryl maleimides remaining after polymerization is preferably 500 ppm or less, more preferably 10 ppm or more and 500 ppm or less, and even more preferably 10 ppm or more and 50 ppm or less, relative to 100 ppm by mass of the polymerization solution at the end of polymerization.

[0295] Within these ranges, the content of fluorescent substances in the methacrylate resin and the resulting light guide component can be suppressed, which is therefore preferable. However, in order to set the amount of unreacted N-substituted maleimide to less than 10 ppm by mass, it is necessary to increase the polymerization temperature or increase the amount of polymerization initiator. Therefore, the thermally modified maleimide and the increase of active free radicals lead to deterioration of the color tone of the methacrylate resin, which is not preferred. As a method for controlling the amount of unreacted N-substituted maleimide within the above-mentioned range after polymerization, a semi-batch polymerization method can be cited. In the semi-batch polymerization method, it is preferable that, from the start of the polymerization initiator until 30 minutes later, the total mass of all monomers supplied for polymerization (e.g., methacrylate, N-substituted maleimide, and any other monomers) is set to 100% by mass, and 5 to 35% by mass of methacrylate monomer is added as a supplement. In other words, it is preferable to add 65-95% by mass of the total monomers supplied for polymerization into the reactor before adding the polymerization initiator, out of a total mass of 100% by mass. Then, 5-35% by mass of the remaining methacrylate monomer is added 30 minutes after the start of the polymerization initiator addition. With the total mass of all monomers supplied for polymerization set at 100% by mass, the amount of methacrylate monomer added is more preferably 10-30% by mass. When the amount of methacrylate monomer added is within the above range, unreacted N-substituted maleimide reacts with the added methacrylate monomer, and the amount of unreacted N-substituted maleimide after polymerization can be controlled within the above range, which is therefore preferable.

[0296] The start time and rate of addition of monomers can be appropriately selected based on the polymerization conversion rate. Furthermore, without hindering the effects of the invention or reducing the amount of unreacted N-substituted maleimide, a monomer mixture containing N-substituted maleimide monomers and other monomers can be added in addition to the methacrylate monomer.

[0297] By employing the semi-batch polymerization method described above, the amount of unreacted N-substituted maleimide monomers in the second half of the polymerization time can be reduced, minimizing the generation of fluorescent luminescent substances in the devolatilization process described later. This allows for the acquisition of methacrylic resins and compositions thereof that exhibit good hue even in light guide components with long optical path lengths, and is therefore preferred.

[0298] The following is a detailed explanation of a method for manufacturing methacrylic resins having structural units derived from N-substituted maleimide monomers, specifically the case where the resin is manufactured using a solution polymerization method with semi-batch free radical polymerization.

[0299] In semi-batch polymerization, it is preferable that, from the start of adding the polymerization initiator until 30 minutes later, the total mass of all monomers supplied for polymerization (methacrylate, N-substituted maleimide, and any other monomers) is set at 100% by mass, and 5-35% by mass of methacrylate monomer is added as a supplement. In other words, it is preferable that 65-95% by mass of the total mass of all monomers supplied for polymerization is charged into the reactor before the start of polymerization, and the remaining 5-35% by mass of methacrylate monomer is added as a supplement after 30 minutes from the start of adding the polymerization initiator.

[0300] The amount of methacrylate monomer added is set to 100% by mass, more preferably 10 to 30% by mass, based on the total mass of all monomers supplied to the polymerization.

[0301] The timing and rate of monomer addition can be appropriately selected based on the polymerization conversion rate.

[0302] In addition, within the range that does not impede the effects of the present invention or the improvement of the conversion rate of N-substituted maleimide monomers, in addition to methacrylate monomers, a monomer mixture containing N-substituted maleimide monomers and other monomers may be added.

[0303] By employing the semi-batch polymerization method described above, the conversion rate of N-substituted maleimide monomers in the second half of the polymerization time can be increased, the content of fluorescent luminescent substances can be reduced, and a resin with excellent light transmittance, long optical path length, easy control of the molecular weight distribution of the obtained polymer, and flowability particularly suitable for injection molding, as well as a composition of the resin, can be obtained, which is therefore preferred.

[0304] (Polymerization solvent)

[0305] As for the polymerization solvent used, there are no particular restrictions as long as it is a solvent that can appropriately maintain the viscosity of the reaction solution, so as to improve the solubility of the maleimide copolymer obtained by polymerization and prevent gelation.

[0306] As specific polymerization solvents, aromatic hydrocarbons such as toluene, xylene, ethylbenzene, and cumene can be used; esters such as methyl isobutyrate; ketones such as methyl isobutyl ketone, butyl cellosolve, methyl ethyl ketone, and cyclohexanone; and polar solvents such as dimethylformamide and 2-methylpyrrolidone can be used.

[0307] These can be used individually or in combination of two or more.

[0308] In addition, within the range that does not hinder the solubility of the polymerization product during polymerization, it can be used as a polymerization solvent in combination with alcohols such as methanol, ethanol, and isopropanol.

[0309] The amount of solvent used in polymerization is not particularly limited, as long as it allows polymerization to proceed, prevents the formation of copolymers and the precipitation of monomers during production, and can be easily removed. For example, when the total amount of the compounded monomers is set to 100% by mass, it is preferably set to 10 to 200% by mass, more preferably 25 to 200% by mass, even more preferably 50 to 200% by mass, and even more preferably 50 to 150% by mass.

[0310] In this embodiment, it is also preferable to use a method in which the total amount of the monomers being polymerized is set to 100% by mass, the amount of solvent used in polymerization is within the range of 100% by mass or less, and polymerization is carried out while the solvent concentration is appropriately changed during polymerization.

[0311] More specifically, examples include methods such as adding 40-60% by mass at the initial stage of polymerization, adding the remaining 60-40% by mass during polymerization, and finally setting the total amount of monomers to 100% by mass, so that the amount of solvent is in the range of 100% by mass or less.

[0312] This method can improve polymerization conversion rate and control molecular weight distribution, thus obtaining resins and resin compositions with excellent injection molding properties, and is therefore preferred.

[0313] In solution polymerization, it is important to minimize the dissolved oxygen concentration in the polymerization solution; for example, the dissolved oxygen concentration is preferably below 10 ppm. The dissolved oxygen concentration can be measured, for example, using a dissolved oxygen meter (DO meter B-505, manufactured by Iijima Electronics Co., Ltd.). Methods for reducing the dissolved oxygen concentration include, appropriately, bubbling an inert gas into the polymerization solution, repeatedly pressurizing the container containing the polymerization solution with an inert gas to approximately 0.2 MPa and then releasing the pressure before polymerization, and introducing an inert gas into the container containing the polymerization solution.

[0314] The polymerization temperature is not particularly limited to any temperature at which polymerization takes place, but is preferably 70–180°C, more preferably 80–160°C, even more preferably 90–150°C, and still more preferably 100–150°C. From a production point of view, it is preferable to set it to 70°C or higher, and to suppress side reactions during polymerization and obtain polymers with the desired molecular weight and quality, it is preferable to set it to 180°C or lower.

[0315] In addition, regarding the polymerization time, it is not particularly limited as long as the required degree of polymerization can be obtained at the required conversion rate. From the point of view of productivity, it is preferred to be 2 to 15 hours, more preferably 3 to 12 hours, and even more preferably 4 to 10 hours.

[0316] (Polymerization initiator)

[0317] As a polymerization initiator, any initiator commonly used in free radical polymerization can be used, such as cumene hydroperoxide, dicumene hydroperoxide, di-tert-butyl peroxide, lauroyl peroxide, benzoyl peroxide, tert-butyl peroxyisopropyl carbonate, tert-amyl peroxy-2-ethylhexanoate, tert-amyl peroxyisononanoate, 1,1-di(tert-butyl peroxy)cyclohexane, etc.; azo compounds such as 2,2'-azobis(isobutyronitrile), 1,1'-azobis(cyclohexaneformitrile), 2,2'-azobis(2,4-dimethylpentanonitrile), dimethyl-2,2'-azobisisobutyrate, etc.

[0318] They can be used individually or in combination of two or more.

[0319] These polymerization initiators can be added at any stage as long as they are in the process of polymerization.

[0320] The amount of polymerization initiator added can be 0.01 to 1% by mass when the total amount of monomers used in the polymerization is set to 100% by mass, preferably 0.05 to 0.5% by mass.

[0321] As for the method of adding the polymerization initiator, there are no particular limitations as long as it is added variably based on the residual monomer concentration in the polymerization solution rather than a fixed addition rate; it can be added continuously or intermittently. In the case of intermittent addition of the polymerization initiator, the amount added per unit time is not considered in relation to the time during which it is not added.

[0322] In this embodiment, it is preferable to appropriately select the type and amount of polymerization initiator, as well as the polymerization temperature, so that the ratio of the total amount of free radicals generated by the polymerization initiator to the total amount of unreacted monomers remaining in the reaction system is always below a constant value.

[0323] By employing these methods, the generation of oligomers and low molecular weight substances in the later stages of polymerization can be suppressed, or overheating during polymerization can be suppressed to achieve polymerization stability.

[0324] (Chain transfer agent)

[0325] During polymerization, chain transfer agents can be added as needed.

[0326] As chain transfer agents, chain transfer agents commonly used in free radical polymerization can be used, such as thiols like n-butylthiol, n-octylthiol, n-decylthiol, n-dodecylthiol, and 2-ethylhexyl mercaptoacetate; halogens like carbon tetrachloride, dichloromethane, and tribromomethane; and unsaturated hydrocarbons like α-methylstyrene dimer, α-terpinene, dipentene, and terpinene.

[0327] They can be used individually or in combination of two or more.

[0328] These chain transfer agents can be added at any stage of the polymerization reaction, as long as they are in progress, without any particular limitation.

[0329] The amount of chain transfer agent added can be 0.01 to 1 part by mass when the total amount of monomers used in the polymerization is set to 100 parts by mass, preferably 0.05 to 0.5 parts by mass.

[0330] There are no particular limitations on the method for recovering polymer from the polymer liquor obtained through solution polymerization. For example, one method may be to add the polymer liquor in the presence of an excess of unsuitable solvents such as hydrocarbon solvents or alcohol solvents that are insoluble in the polymer obtained through polymerization, and then perform pretreatment such as liquid-liquid extraction or solid-liquid extraction on the unreacted monomers to separate them from the polymer liquor using a homogenizer (emulsification dispersion); or another method may be to separate the polymerization solvent and unreacted monomers and recover the polymer products through a process called devolatilization.

[0331] Here, the devolatilization process refers to the process of removing volatile components such as polymerization solvents, residual monomers, and reaction byproducts under heating / reduced pressure conditions.

[0332] Examples of devices used in the aforementioned devolatilization process include devolatilization devices consisting of a tubular heat exchanger and a devolatilization tank. In addition, examples of devices with rotating parts include thin-film evaporators such as the Wiprene and EXeva manufactured by Kobe Steel Environmental Solutions, and the KONTRO and tilting-blade KONTRO manufactured by Hitachi, Ltd., as well as extruders with vents that provide sufficient residence time and surface area to fully utilize devolatilization performance.

[0333] It can also be used in devolatilization processes that combine any two or more of these devices.

[0334] For resin compositions constituting light guide components used in applications emphasizing high image contrast, it is important to suppress reaction byproducts exhibiting fluorescence. To suppress the formation of these byproducts and obtain methacrylic resins with good color tone, methods such as: extending the polymerization time as much as possible to improve monomer conversion, or altering the addition rate of the polymerization initiator according to the concentration of unreacted monomers in the polymerization solution; performing polymerization while appropriately changing the solvent concentration; supplementing with other monomers highly reactive with residual N-substituted maleimide monomers during the latter half of polymerization; or adding compounds highly reactive with N-substituted maleimide, such as α-terpinene, at the end of polymerization.

[0335] From the perspective of improving the color scheme, it is preferable to use a devolatilization device whose main structure consists of a heat exchanger and a pressure reducing vessel, and which does not have a rotating part in its structure.

[0336] Specifically, a devolatilization device consisting of a devolatilization tank and a discharge device can be used, wherein the devolatilization tank is configured to have a heat exchanger disposed on its upper part and a pressure reducing unit attached to a pressure reducing vessel having a size capable of devolatilization, and the discharge device is a gear pump or the like for discharging the devolatilized polymer.

[0337] In the aforementioned devolatilization apparatus, the polymerization solution is preheated in a heat exchanger located above a vacuum vessel and heated, and then fed into a devolatilization tank under heating / depressurization conditions to separate and remove the polymerization solvent, unreacted raw material mixture, polymerization byproducts, etc., from the copolymer. Examples of heat exchangers include multi-tube heat exchangers, finned heat exchangers, and plate-type heat exchangers with flat flow paths and heaters. By using a devolatilization apparatus without a rotating part as described above, methacrylic resins with good color tone can be obtained, and this is therefore preferred.

[0338] In this embodiment, a flat-plate heat exchanger having a flat-plate flow path and a heater is preferably used as the heat exchanger disposed on the upper part of the pressure reducing vessel. More preferably, a flat-plate heat exchanger having a flat-plate flow path and a heater, wherein the flat-plate flow path has a stacked structure, and the stacked structure has a plurality of slit-shaped flow paths with a rectangular cross-section on the same plane.

[0339] The polymerization solution supplied to the devolatilization unit is conveyed from the central part of the heat exchanger to the slit-shaped flow path and heated. The heated polymerization solution is then supplied from the slit-shaped flow path to a depressurized vessel integrated with the heat exchanger for flash evaporation.

[0340] This method of devouring is sometimes referred to as rapid devouring, and in this invention, it will also be referred to as rapid devouring.

[0341] The polymerization solution supplied to the devolatilization unit is conveyed from the central part of the heat exchanger to the slit-shaped flow path and heated. The heated polymerization solution is then fed from the slit-shaped flow path into a depressurized vessel integrated with the heat exchanger for flash evaporation.

[0342] This type of devouring method is sometimes referred to as rapid devouring, and in this invention, it will also be referred to as rapid devouring.

[0343] The processing temperature in the devolatilization apparatus is between the glass transition temperature (Tg) of the methacrylic resin and 100°C, and between the glass transition temperature (Tg) and 160°C. Specifically, the processing temperature is preferably 150–350°C, more preferably 180–310°C, and even more preferably 200–290°C. By setting the temperature above the lower limit mentioned above, residual volatile components can be suppressed; by setting the temperature below the upper limit mentioned above, coloring and decomposition of the obtained methacrylic resin can be suppressed.

[0344] The vacuum level inside the devolatilization tank can be set in the range of 5 to 300 Torr, preferably in the range of 10 to 200 Torr. If the vacuum level is below 300 Torr, unreacted monomers or mixtures of unreacted monomers and polymerization solvents can be effectively separated and removed without reducing the thermal stability and quality of the obtained thermoplastic copolymer. If the vacuum level is above 5 Torr, industrial implementation is easier.

[0345] The average residence time in the devolatilization tank can be 5 to 60 minutes, preferably 5 to 45 minutes. If the average residence time is within this range, devolatilization can be carried out effectively, and coloring and decomposition caused by the thermal modification of the polymer can be suppressed, so it is preferred.

[0346] The polymer recovered through the devolatilization process is processed into granules using a process known as granulation.

[0347] In the granulation process, at least one conveying granulation device selected from gear pumps with multi-hole molds as auxiliary equipment, single-screw extruders, and twin-screw extruders is used to extrude molten resin in the form of strands, and the resin is processed into granules by cold cutting, air hot cutting, underwater wire harness cutting, and underwater cutting.

[0348] In this embodiment, in order to obtain a highly controlled resin composition, it is preferable to use a granulation method that minimizes the contact between the resin composition, which is in a molten state at high temperature, and allows for rapid cooling and solidification.

[0349] In this case, it is preferable to reduce the temperature of the molten resin to the extent possible, and to minimize the residence time from the outlet of the porous mold to the surface of the cooling water, while also using a higher temperature of the cooling water as possible, and to carry out granulation under feasible conditions.

[0350] For example, the melting resin temperature is preferably 220 to 280°C, more preferably 230 to 270°C, the residence time from the porous mold outlet to the cooling water surface is preferably less than 5 seconds, more preferably less than 3 seconds, and the cooling water temperature is preferably in the range of 30 to 80°C, more preferably 40 to 60°C.

[0351] By implementing the process within these ranges of molten resin temperature and cooling water temperature, it is possible to obtain methacrylic resins and their compositions with less coloring and lower moisture content, which is therefore preferred.

[0352] From the viewpoint of thermal stability and product quality, it is preferable to have a lower content of residual monomers in the methacrylate resin after the devolatilization process. Specifically, the content of methacrylate monomers is preferably 3000 ppm by mass or less, more preferably 2000 ppm by mass or less. The content of N-substituted maleimide monomers is preferably 200 ppm by mass or less, more preferably 100 ppm by mass or less, in total.

[0353] In addition, the content of residual polymerization solvent is preferably 500 ppm by mass or less, more preferably 300 ppm by mass or less.

[0354] --Method for manufacturing methacrylic resins containing glutarimide structural units--

[0355] As a method for manufacturing methacrylic resins having glutarimide-based structural units in the main chain, any one of the following polymerization methods can be cited: bulk polymerization, solution polymerization, suspension polymerization, precipitation polymerization, and emulsion polymerization. Suspension polymerization, bulk polymerization, and solution polymerization are preferred, and solution polymerization is even more preferred.

[0356] In the manufacturing method of this embodiment, as a polymerization method, for example, any one of batch polymerization, semi-batch polymerization, or continuous polymerization can be used.

[0357] In the manufacturing method of this embodiment, a method of polymerizing monomers by free radical polymerization is preferred.

[0358] Methacrylic resins having glutarimide structural units in their main chain, such as those described in Japanese Patent Application Publication No. 2006-249202, Japanese Patent Application Publication No. 2007-009182, Japanese Patent Application Publication No. 2007-009191, Japanese Patent Application Publication No. 2011-186482, and International Publication No. 2012 / 114718, can be formed by the methods described in those publications.

[0359] The following is a detailed description of an example of a method for manufacturing methacrylic resins having glutarimide structural units, in which solution polymerization is used to manufacture the resin via batch free radical polymerization.

[0360] First, a (meth)acrylate polymer is produced by polymerizing (meth)acrylates such as methyl methacrylate. In the case where an aromatic vinyl unit is included in a methacrylate resin having glutarimide structural units, a (meth)acrylate-aromatic vinyl copolymer is produced by copolymerizing the (meth)acrylate with an aromatic vinyl monomer (e.g., styrene).

[0361] Examples of solvents used in polymerization include aromatic hydrocarbons such as toluene, xylene, and ethylbenzene; and ketones such as methyl ethyl ketone and methyl isobutyl ketone.

[0362] These solvents can be used alone or in combination of two or more.

[0363] The amount of solvent used during polymerization is not particularly limited, as long as it allows polymerization to proceed, does not cause precipitation of copolymers or monomers during production, and can be easily removed. For example, when the total amount of the compounded monomers is set to 100% by mass, 10 to 200% by mass is preferred. The amount of solvent used during polymerization is more preferably 25 to 200% by mass, more preferably 50 to 200% by mass, and even more preferably 50 to 150% by mass.

[0364] The polymerization temperature is not particularly limited to any temperature at which polymerization takes place, but is preferably 50–200°C, more preferably 80–200°C. Further preferably, the polymerization temperature is 90–150°C, even more preferably 100–140°C, and still more preferably 100–130°C. From a production point of view, the polymerization temperature is preferably set to 50°C or higher, and to suppress side reactions during polymerization and obtain polymers with the desired molecular weight and quality, it is preferably set to 200°C or lower.

[0365] As for the aggregation time, there is no particular limitation as long as the desired conversion rate is met. However, from the point of view of productivity, it is preferred to be 0.5 to 15 hours, more preferably 2 to 12 hours, and even more preferably 4 to 10 hours.

[0366] During polymerization, polymerization initiators and chain transfer agents can be added as needed.

[0367] There are no particular limitations on the polymerization initiator; for example, polymerization initiators disclosed in the preparation method of methacrylic resin having structural units derived from the above-described N-substituted maleimide monomer can be used.

[0368] These polymerization initiators can be used alone or in combination of two or more.

[0369] These polymerization initiators can be added at any stage as long as they are in the process of polymerization.

[0370] The amount of polymerization initiator added can be set appropriately according to the combination of monomers and reaction conditions, and there is no particular limitation. When the total amount of monomers used in polymerization is set to 100% by mass, it can be set to 0.01 to 1% by mass, preferably 0.05 to 0.5% by mass.

[0371] As a chain transfer agent, chain transfer agents used in conventional free radical polymerization can be used, such as the chain transfer agents disclosed in the section on the manufacturing method of methacrylic resins having structural units derived from N-substituted maleimide monomers.

[0372] They can be used individually or in combination of two or more.

[0373] These chain transfer agents can be added at any stage of the polymerization reaction, as long as they are in progress, without any particular limitation.

[0374] The amount of chain transfer agent added is not particularly limited as long as it is within the range that can achieve the desired degree of polymerization under the polymerization conditions used. Preferably, when the total amount of monomers used in the polymerization is set to 100% by mass, it can be 0.01 to 1% by mass, preferably 0.05 to 0.5% by mass.

[0375] The appropriate method for adding polymerization initiators and chain transfer agents in the polymerization process can be, for example, the method described in the preparation method of methacrylic resin having structural units derived from the above-mentioned N-substituted maleimide monomers.

[0376] The dissolved oxygen concentration in the polymerization solution may, for example, be a value disclosed in a method for preparing a methacrylic resin having structural units derived from the aforementioned N-substituted maleimide monomer.

[0377] Then, an imidization reaction (imidization step) is carried out by reacting the above-mentioned (meth)acrylate polymer or the above-mentioned methacrylate-aromatic vinyl copolymer with an imidizing agent. This allows the manufacture of methacrylate resins having glutarimide structural units.

[0378] There are no particular limitations on the imidizing agent mentioned above, as long as it can generate a glutarimide structural unit represented by the above general formula (3).

[0379] Specifically, ammonia or primary amines can be used as imidizing agents. Examples of such primary amines include methylamine, ethylamine, n-propylamine, isopropylamine, n-butylamine, isobutylamine, tert-butylamine, n-hexylamine, and other primary amines containing aliphatic hydrocarbon groups; and cyclohexylamine and other primary amines containing alicyclic hydrocarbon groups.

[0380] Among the above imidizing agents, ammonia, methylamine, and cyclohexylamine are preferred from the perspectives of cost and physical properties, with methylamine being particularly preferred.

[0381] In this imidization process, by adjusting the addition ratio of the imidizing agent, the content of glutarimide structural units in the obtained methacrylic resin having glutarimide structural units can be adjusted.

[0382] There are no particular limitations on the method for carrying out the above imidization reaction. Conventionally known methods can be used, for example, imidization reaction can be carried out by using an extruder or a batch reaction tank.

[0383] There are no particular limitations on the extruder used; for example, a single-screw extruder, a twin-screw extruder, or a multi-screw extruder can be used. Among these, a twin-screw extruder is preferred. With a twin-screw extruder, the mixing of the raw material polymer and the imidizing agent can be facilitated.

[0384] Examples of twin-screw extruders include non-meshing co-rotating, meshing co-rotating, non-meshing counter-rotating, and meshing counter-rotating types.

[0385] The extruders in the above example can be used individually or in series in multiples.

[0386] In addition, the extruder is equipped with a vent that can reduce the pressure to below atmospheric pressure, which can remove byproducts or monomers such as imidizing agents and methanol from the reaction, making it particularly preferred.

[0387] When manufacturing methacrylic resins having glutarimide-based structural units, in addition to the imidization step described above, an esterification step can be included to treat the carboxyl groups of the resin using an esterifying agent such as dimethyl carbonate. In this case, catalysts such as trimethylamine, triethylamine, and tributylamine can also be used in combination for treatment.

[0388] For the esterification process, similar to the imidization process described above, it can be carried out, for example, by using an extruder or a batch reaction tank.

[0389] Furthermore, to remove excess esterifying agents, methanol, and other byproducts or monomers, it is preferable to install a vent on the device capable of reducing pressure to below atmospheric pressure. In this case, if carboxyl esterification cannot be performed, residual carboxyl groups will increase the resin's water absorption rate, leading to deterioration of the surface accuracy of the light guide component during reliability tests in high-humidity environments. Additionally, if esterifying agents such as dimethyl carbonate and amines are not sufficiently devolatilized, acidic and alkaline substances will remain, which is therefore undesirable.

[0390] For methacrylic resins that have undergone imidization and esterification processes as needed, they are melted and extruded in a wire-like manner from an extruder with a multi-hole die, and then processed into granules using methods such as cold cutting, air hot cutting, underwater wire harness cutting, and underwater cutting.

[0391] In addition, to reduce the amount of foreign matter in the resin, it is preferable to use a method that involves dissolving the methacrylic resin in organic solvents such as toluene, methyl ethyl ketone, and dichloromethane, filtering the resulting methacrylic resin solution, and then volatilizing the organic solvent.

[0392] From the viewpoint of reducing fluorescence intensity (the content of fluorescent luminescent substances), it is preferable to perform imidization in a batch reaction tank after polymerization and not to use a twin-screw extruder that is subject to shear forces.

[0393] The imidization reaction is preferably carried out at 130–250°C, more preferably at 150–230°C, and even more preferably at 170–190°C. Furthermore, the reaction time is preferably 10 minutes to 5 hours, more preferably 30 minutes to 2 hours.

[0394] From the viewpoint of reducing fluorescence intensity, it is preferable to perform a devolatilization process after the imidization step, followed by an esterification step as needed, and then perform granulation after devolatilization using the devolatilization method described in the above-mentioned method for preparing methacrylic resins having structural units derived from N-substituted maleimide monomers.

[0395] --Method for manufacturing methacrylic resins containing lactone ring structural units--

[0396] As a method for manufacturing methacrylic resins having lactone ring structural units in the main chain, a method is used to form lactone ring structures by cyclization reaction after polymerization. Preferably, the monomer is polymerized by free radical polymerization using a solution polymerization method with a solvent, based on promoting the cyclization reaction.

[0397] In the manufacturing method of this embodiment, as a polymerization method, for example, any one of batch polymerization, semi-batch polymerization, or continuous polymerization can be used.

[0398] Methacrylic acid resins having lactone ring structural units in the main chain can be formed, for example, by the methods described in Japanese Patent Application Publication Nos. 2001-151814, 2004-168882, 2005-146084, 2006-96960, 2006-171464, 2007-63541, 2007-297620, and 2010-180305.

[0399] The following is an example of a method for manufacturing methacrylic resins having lactone ring structural units, specifically illustrating the case where the resin is manufactured by solution polymerization in a batch manner via free radical polymerization.

[0400] As a method for manufacturing methacrylic resins having lactone ring structural units, a method is used to form lactone ring structures by cyclization reaction after polymerization, preferably by solution polymerization using a solvent to promote cyclization reaction.

[0401] Examples of solvents used in polymerization include aromatic hydrocarbons such as toluene, xylene, and ethylbenzene; and ketones such as methyl ethyl ketone and methyl isobutyl ketone.

[0402] These solvents can be used alone or in combination of two or more.

[0403] As for the amount of solvent during polymerization, there are no particular limitations as long as the conditions that allow polymerization to proceed and inhibit gelation are met. For example, when the total amount of the complexed monomers is set to 100% by mass, it is preferable to set it to 50 to 200% by mass, and more preferably 100 to 200% by mass.

[0404] To effectively suppress gelation of the polymerization solution and promote the cyclization reaction after polymerization, polymerization is preferably carried out in a manner where the concentration of the polymer generated in the reaction mixture after polymerization is 50% by mass or less. Furthermore, it is preferable to appropriately add a polymerization solvent to the reaction mixture and control the concentration to be 50% by mass or less as described above.

[0405] There are no particular limitations on the method of appropriately adding the polymerization solvent to the reaction mixture; for example, the polymerization solvent can be added continuously or intermittently.

[0406] The added polymerization solvent can be a single solvent or a mixture of two or more solvents.

[0407] As for the polymerization temperature, any temperature at which polymerization takes place is acceptable and there are no particular limitations. From a production point of view, 50 to 200°C is preferred, and 80 to 180°C is more preferred.

[0408] As for the aggregation time, it is acceptable as long as the desired conversion rate is met, and there are no particular restrictions. From the point of view of productivity, it is preferred to be 0.5 to 10 hours, and more preferably 1 to 8 hours.

[0409] During polymerization, polymerization initiators or chain transfer agents can be added as needed.

[0410] There are no particular limitations on the polymerization initiator; for example, polymerization initiators disclosed in the above-described method for preparing methacrylic resins having structural units derived from N-substituted maleimide monomers can be used.

[0411] These polymerization initiators can be used alone or in combination of two or more.

[0412] These polymerization initiators can be added at any stage as long as they are in the process of polymerization.

[0413] The amount of polymerization initiator added can be set appropriately according to the combination of monomers and reaction conditions, without any particular limitation. When the total amount of monomers used in polymerization is set to 100% by mass, it can be set to 0.05 to 1% by mass.

[0414] As a chain transfer agent, chain transfer agents used in conventional free radical polymerization can be used, such as the chain transfer agents disclosed in the section on the manufacturing method of methacrylic resins having structural units derived from N-substituted maleimide monomers.

[0415] They can be used individually or in combination of two or more.

[0416] These chain transfer agents can be added at any stage of the polymerization reaction, as long as they are in progress, without any particular limitation.

[0417] The amount of chain transfer agent added is not particularly limited as long as it is within the range that can achieve the desired degree of polymerization under the polymerization conditions used. Preferably, when the total amount of monomers used in the polymerization is set to 100% by mass, it can be 0.05 to 1% by mass.

[0418] Preferred methods for adding polymerization initiators and chain transfer agents in the polymerization process can be, for example, the methods described in the above-described method for manufacturing methacrylic resins having structural units derived from N-substituted maleimide monomers.

[0419] The concentration of dissolved oxygen in the polymerization solution can be, for example, the value disclosed in the above-described method for manufacturing methacrylic resins having structural units derived from N-substituted maleimide monomers.

[0420] The methacrylic acid resin with lactone ring structural units in this embodiment can be obtained by cyclization reaction after the above polymerization reaction is completed. Therefore, it is preferable to supply the lactone cyclization reaction in a solvent-containing state without removing the polymerization solvent from the polymerization reaction solution.

[0421] For copolymers obtained by polymerization, heat treatment is used to induce a cyclization condensation reaction between hydroxyl (hydroxyl) groups and ester groups present in the molecular chain of the copolymer, thereby forming an lactone ring structure.

[0422] During the heat treatment to form the lactone ring structure, reaction equipment equipped with a vacuum device or a devolatilization device for removing alcohols that may be produced as byproducts of cyclization condensation, or an extruder equipped with a devolatilization device, can also be used.

[0423] In order to promote the cyclization condensation reaction during the formation of the lactone ring structure, a cyclization condensation catalyst can be used for heating treatment as needed.

[0424] Specific examples of cyclization condensation catalysts include, for instance, monoalkyl, dialkyl, or trialkyl phosphites such as methyl phosphite, ethyl phosphite, phenyl phosphite, dimethyl phosphite, diethyl phosphite, diphenyl phosphite, trimethyl phosphite, and triethyl phosphite; monoalkyl, dialkyl, or trialkyl phosphite esters such as methyl phosphite, ethyl phosphite, 2-ethylhexyl phosphite, octyl phosphite, isodecanyl phosphite, lauryl phosphite, stearyl phosphite, isostearyl phosphite, dimethyl phosphite, diethyl phosphite, di-2-ethylhexyl phosphite, diisodecyl phosphite, dilauryl phosphite, disostearyl phosphite, diisostearyl phosphite, trimethyl phosphite, triethyl phosphite, triisodecyl phosphite, trilauryl phosphite, tristearyl phosphite, and triisostearyl phosphite; and organozinc compounds such as zinc acetate, zinc propionate, and octyl zinc.

[0425] These can be used individually or in combination of two or more.

[0426] The amount of cyclization condensation catalyst used is not particularly limited, but for example, it is preferably 0.01 to 3% by mass, more preferably 0.05 to 1% by mass, relative to 100% by mass of the methacrylic resin.

[0427] If the amount of catalyst used is 0.01% by mass or more, the reaction rate of the cyclization condensation reaction is effectively increased. If the amount of catalyst used is less than 3% by mass, the coloring of the obtained polymer and the cross-linking of the polymer are effectively prevented, making it difficult to melt-form.

[0428] There is no particular limitation on the timing of addition of the catalyst for cyclization condensation. For example, it can be added at the beginning of the cyclization condensation reaction, during the reaction, or at both of these stages.

[0429] During cyclization condensation reactions in the presence of a solvent, devolatilization can also occur simultaneously.

[0430] The apparatus used in the case of simultaneously performing cyclization condensation reaction and devolatilization process is not particularly limited. It can be a devolatilization device consisting of a heat exchanger and a devolatilization tank or an extruder with vent holes. In addition, it is preferred to have an apparatus in series with the devolatilization device and the extruder, and more preferably a twin-screw extruder with vent holes.

[0431] As for the twin-screw extruder with vent holes used, an extruder with vent holes having a plurality of vent ports is preferred.

[0432] When using an extruder with vents, the reaction processing temperature is preferably 150–350°C, more preferably 200–300°C. If the reaction processing temperature is below 150°C, the cyclization condensation reaction may become incomplete, sometimes resulting in an increase in residual volatile components. Conversely, if the reaction processing temperature is above 350°C, it may sometimes cause discoloration and decomposition of the resulting polymer.

[0433] When using an extruder with vents, the vacuum level is preferably 10 to 500 Torr, more preferably 10 to 300 Torr. If the vacuum level is greater than 500 Torr, volatile components may sometimes remain. Conversely, if the vacuum level is less than 10 Torr, industrial implementation may sometimes become difficult.

[0434] When carrying out the above-mentioned cyclization condensation reaction, it is also preferable to add alkaline earth metal and / or amphoteric metal salts of organic acids during granulation in order to deactivate the residual cyclization condensation catalyst.

[0435] Alkaline earth metal and / or amphoteric metal salts that are organic acids, such as calcium acetoacetate, calcium stearate, zinc acetate, zinc octanoate, zinc 2-ethylhexanoate, etc., can be used.

[0436] After undergoing the cyclization and condensation reaction process, the methacrylic resin is melted and extruded in a wire-like form from an extruder with a porous die, and then processed into granules using cold cutting, air hot cutting, underwater wire harness cutting, and underwater cutting methods.

[0437] It should be noted that the aforementioned lactone formation for forming lactone ring structural units can be carried out after the manufacture of the resin and before the manufacture of the resin composition (described later), or it can be carried out during the manufacture of the resin composition, together with the melt blending of the resin and other components.

[0438] From the viewpoint of reducing fluorescence intensity (the content of fluorescent luminescent substances), it is preferable to perform lactone cyclization in a batch reaction tank after polymerization without using a twin-screw extruder subjected to shear forces. From the viewpoint of reducing fluorescence intensity, it is preferable to perform granulation after the lactone cyclization step, following the devolatilization method described in the above-described method for preparing methacrylic resins having structural units derived from N-substituted maleimide monomers.

[0439] --Method for manufacturing methacrylic resins containing aromatic ring hydrogenated structural units--

[0440] As a method for manufacturing methacrylic resins having aromatic ring hydrogenated structural units, a method for manufacturing nuclear hydrogenated polymers is used by hydrogenating a copolymer of an aromatic vinyl compound and a (meth)acrylate in the presence of a hydrogenation catalyst and a reaction solvent.

[0441] The polymerization of monomers containing aromatic vinyl compounds and (meth)acrylates can be carried out using known methods, as long as the free radical polymerization method is simple to use industrially. Free radical polymerization can appropriately select known methods such as bulk polymerization, solution polymerization, emulsion polymerization, and suspension polymerization; however, to avoid the presence of water during the hydrogenation reaction, bulk polymerization or solution polymerization is preferred. In the manufacturing method of this embodiment, as the polymerization form, for example, any of batch polymerization, semi-batch polymerization, and continuous polymerization can be used.

[0442] As a method for manufacturing methacrylic resins containing aromatic ring hydrogenated structural units, for example, it can be formed by the methods described in Japanese Patent Application Publication No. 2006-291184, Japanese Patent Application Publication No. 2014-77043, and Japanese Patent Application Publication No. 2014-77044.

[0443] The following is a specific example of a method for manufacturing a methacrylic resin containing aromatic ring hydrogenated structural units, obtained by hydrogenating a copolymer of an aromatic vinyl compound and a (meth)acrylate.

[0444] As a solvent used in polymerization, it is necessary to consider the solvent's own stability under reaction conditions, good solubility of the copolymer before and after hydrogenation (copolymers of aromatic vinyl compounds and (meth)acrylates and nucleopolymers obtained by hydrogenating aromatic rings), and rapid reaction. Furthermore, a high ignition point of the solvent is also important when considering the potential for devolatilization of the solvent components after the reaction. Examples of solvents that meet these conditions include hydrocarbon compounds such as n-pentane, n-hexane, n-octane, and cyclohexane; ether compounds such as 1,4-dioxane, tetrahydrofuran, ethylene glycol dimethyl ether, and diethylene glycol dimethyl ether; amide compounds such as dimethylformamide and dimethylacetamide; and ester compounds, with ether compounds and ester compounds being particularly preferred. Tetrahydrofuran is particularly preferred as an ether compound. These solvents can be used alone or in combination of two or more.

[0445] As an ester compound, a carboxylic acid ester compound is preferred. The carboxylic acid ester compound is an aliphatic ester compound, preferably a compound represented by the following general formula (5).

[0446] R 51 -COO-R 52 (5)

[0447] In general formula (5), R 51 R is an alkyl group having 1 to 6 carbon atoms. 52 It is an alkyl group having 1 to 6 carbon atoms. As R 51 and R 52Examples of ester compounds include methyl, ethyl, propyl, isopropyl, butyl, isobutyl, pentyl, hexyl, and cyclohexyl. Methyl acetate, ethyl acetate, n-butyl acetate, amyl acetate, methyl propionate, ethyl propionate, n-propyl propionate, n-butyl propionate, methyl butyrate, methyl isobutyrate, n-butyl butyrate, methyl valerate, and methyl hexanoate are used, and methyl acetate, ethyl acetate, methyl propionate, methyl isobutyrate, and methyl butyrate are particularly preferred.

[0448] The concentration of the copolymer (a copolymer of aromatic vinyl compounds and (meth)acrylates and a nucleopolymer obtained by hydrogenating the aromatic ring) in the solution during the hydrogenation reaction is typically 1 to 50% by weight, preferably 3 to 30% by weight, and more preferably 5 to 25% by weight. If the copolymer concentration is too high, it is not preferred due to considerations such as reduced reaction rate or increased solution viscosity leading to inconvenience in handling; if the concentration is too low, it is not preferred from a productivity and economic perspective.

[0449] The water concentration in the polymer solution before hydrogenation is 0.5% by weight or less, preferably 0.2% by weight or less, and more preferably 0.05% by weight or less. If the water content is greater than 0.5% by weight, the resulting nuclear hydrogenated polymer (particles, powder) may sometimes be colored, making it less desirable as an optical material.

[0450] During polymerization, polymerization initiators and chain transfer agents can be added as needed, but sulfur content can hinder hydrogenation reactions, so it is preferable to avoid sulfur as much as possible.

[0451] As a polymerization initiator, any polymerization initiator that does not have a sulfur functional group is acceptable and there are no particular limitations. For example, polymerization initiators disclosed in the preparation method of methacrylic resin having the structural units derived from N-substituted maleimide monomers can be used.

[0452] These polymerization initiators can be used alone or in combination of two or more.

[0453] These polymerization initiators can be added at any stage as long as they are in the process of polymerization.

[0454] The amount of polymerization initiator added can be set appropriately according to the combination of monomers and reaction conditions, and there is no particular limitation. When the total amount of monomers used in polymerization is set to 100% by mass, it can be 0.05 to 1% by mass.

[0455] Preferred methods for adding polymerization initiators and chain transfer agents in the polymerization process can be, for example, the methods described in the above-described method for preparing methacrylic resins having structural units derived from N-substituted maleimide monomers.

[0456] The concentration of dissolved oxygen in the polymerization solution can be, for example, the value disclosed in the above-described method for manufacturing methacrylic resins having structural units derived from N-substituted maleimide monomers.

[0457] Chain transfer agents are not necessarily required. Furthermore, when using them, it is preferable to use tetrahalides such as carbon tetrachloride, carbon tetrabromide, and carbon tetraiodide, or styrene dimers such as 2,4-diphenyl-4-methyl-1-pentene. Commonly used thiol-based chain transfer agents introduce sulfur functional groups to the polymer terminus, which hinders the hydrogenation reaction of aromatic rings, and are therefore not preferred.

[0458] They can be used individually or in combination of two or more.

[0459] These chain transfer agents can be added at any stage of the polymerization reaction, as long as they are in progress, without any particular limitation.

[0460] The amount of chain transfer agent added is not particularly limited as long as it is within the range that can achieve the desired degree of polymerization under the polymerization conditions used. Preferably, when the total amount of monomers used in the polymerization is set to 100% by mass, it can be 0.05 to 1% by mass.

[0461] It should be noted that when thiol-based chain transfer agents are not typically used, the thermal decomposability of the raw material polymer decreases. However, for methacrylic resins containing aromatic ring hydrogenated structural units, the decomposition temperature and other physical properties depend only on the hydrogenation rate. If the hydrogenation rate is the same, the use of thiol-based chain transfer agents does not affect the decomposition temperature.

[0462] As a catalyst used in a hydrogenation reaction (hydrogenation catalyst), any catalyst with hydrogenation activity is acceptable, and there are no particular limitations. Specifically, examples include nickel, ruthenium, rhodium, palladium, and platinum. Among these, palladium supported on a support is particularly preferred because it exhibits high reaction rates, does not cause side reactions in the solvent, and remains stable before and after the reaction. Commonly used catalyst supports include activated carbon, alumina (Al₂O₃), silica (SiO₂), silica-alumina (SiO₂-Al₂O₃), diatomaceous earth, and zirconium oxide. There are no limitations on the catalyst support used in this invention, but activated carbon, alumina, or zirconium oxide are preferred.

[0463] The loading of palladium metal on the support is typically in the range of 0.01 to 50% by weight, preferably 0.05 to 20% by weight, and more preferably 0.1 to 10% by weight. Economically, it is preferable to use as little expensive palladium as possible; however, when activated carbon or zirconium oxide is used as the support, palladium can be loaded with high dispersion. Furthermore, the reaction rate per unit of palladium is very high, thus maintaining a sufficient reaction rate even when the palladium loading is set to 0.1 to 1.0% by weight. It should be noted that known methods such as pulse adsorption of carbon monoxide are used to determine the dispersion of palladium.

[0464] As precursors to palladium, known salts or complexes such as palladium chloride, palladium nitrate, and palladium acetate can be used. When impregnated and loaded onto a support, the precursor is prepared into a solution. Examples of precursor / solvent combinations include palladium chloride / hydrochloric acid solution, palladium chloride / sodium chloride solution, palladium nitrate / water, palladium nitrate / hydrochloric acid solution, palladium acetate / hydrochloric acid solution, and palladium acetate / organic solvent.

[0465] The preferred conditions for hydrogenation reactions are a temperature of 60–250°C, a hydrogen pressure of 3–30 MPa, and a reaction time of 3–20 hours. If the reaction temperature is too low, the reaction rate slows down; if the reaction temperature is too high, side reactions such as polymer decomposition and solvent hydrogenation decomposition may occur, making these conditions undesirable. Furthermore, the reaction rate is slow at low hydrogen pressures; conversely, further increasing the hydrogen pressure requires a high-pressure-resistant reactor, making this economically undesirable.

[0466] By separating the hydrogenation catalyst and volatile components (solvents, etc.) from the polymer solution after the hydrogenation reaction, a nuclear hydrogenated polymer can be obtained.

[0467] Catalyst separation can be carried out by known methods such as filtration or centrifugation. Considering factors such as coloration and impact on mechanical properties, the concentration of residual catalyst metal in the polymer needs to be minimized, preferably below 10 ppm, and more preferably below 1 ppm.

[0468] After separating the catalyst, as a method for purifying the polymer by separating volatile components such as solvent from the obtained nuclear hydrogenated polymer solution, it is preferable to perform granulation after devolatilization by the devolatilization method described in the above-described method for preparing methacrylic resin having structural units derived from N-substituted maleimide monomers.

[0469] <<Additives>>

[0470] The resin composition constituting the light guide component of this embodiment may contain various additives without significantly impairing the effects of the present invention.

[0471] As an additive, there are no particular limitations. Examples include antioxidants, hindered amine light stabilizers and other light stabilizers, ultraviolet absorbers, release agents, other thermoplastic resins other than methacrylic resins, paraffinic processing oils, naphthenic processing oils, aromatic processing oils, paraffin wax, organopolysiloxanes, mineral oils and other softeners / plasticizers, flame retardants, antistatic agents, organic fibers, iron oxides and other pigments and other inorganic fillers, glass fibers, carbon fibers, metal whiskers and other reinforcing agents, colorants, phosphites, phosphonites, phosphates and other organophosphorus compounds, other additives or mixtures thereof.

[0472] -Antioxidants-

[0473] Preferably, the resin composition of the light guide component constituting the light guide component of this embodiment contains an antioxidant that inhibits deterioration and discoloration during molding or use.

[0474] The antioxidants described herein are not limited to the following substances; examples include hindered phenolic antioxidants, phosphorus-based antioxidants, and sulfur-based antioxidants. One or more of these antioxidants may be used.

[0475] Furthermore, from the viewpoint of improving thermal stability and suppressing molding defects, it is preferable to use multiple heat stabilizers together. For example, it is preferable to use at least one selected from phosphorus-based antioxidants and sulfur-based antioxidants together with a hindered phenolic antioxidant.

[0476] As hindered phenolic antioxidants, they are not limited to the following substances, for example, pentaerythritol tetra[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate], thiodiethylenebis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate], octadecyl-3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate, 3,3',3'',5,5',5''-hexa-tert-butyl-a,a',a''-(trimethylbenzene-2,4,6-triyl)tri-p-cresol, 4,6-bis(octylthiomethyl)-o-cresol, 4,6-bis(dodecylthiomethyl)-o-cresol, ethylenebis(ethylene oxide)bis[3-(5-tert-butyl-4-hydroxy-m-tolyl)propionate], hexamethylenebis[3-(3,5-di-tert-butyl-4-hydroxy-m-tolyl)propionate], etc. [-di-tert-butyl-4-hydroxyphenyl)propionate], 1,3,5-tris(3,5-di-tert-butyl-4-hydroxybenzyl)-1,3,5-triazine-2,4,6(1H,3H,5H)-trione, 1,3,5-tris[(4-tert-butyl-3-hydroxy-2,6-xylyl)methyl]-1,3,5-triazine-2,4,6(1H,3H,5H)-trione, 2,6-di-tert-butyl-4-(4,6-bis(octylthio)-1,3,5-triazine-2-ylamine)phenol, 2-[1-(2-hydroxy-3,5-di-tert-pentylphenyl)ethyl]-4,6-di-tert-pentylphenyl acrylate, 2-tert-butyl-4-methyl-6-(2-hydroxy-3-tert-butyl-5-methylbenzyl)phenyl acrylate, etc.

[0477] Pentaerythritol tetra[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate], octadecyl-3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate, and 2-[1-(2-hydroxy-3,5-di-tert-pentylphenyl)ethyl]-4,6-di-tert-pentylphenyl acrylate are particularly preferred.

[0478] In addition, hindered phenolic antioxidants can be commercially available phenolic antioxidants. These commercially available phenolic antioxidants are not limited to the following substances: for example, Irganox 1010 (Irganox 1010: pentaerythritol tetra[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate], manufactured by BASF), Irganox 1076 (Irganox 1076: octadecyl-3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate, manufactured by BASF), Irganox 1330 (Irganox 1330: 3,3',3'',5,5',5''-hexa-tert-butyl-a,a',a''-(trimethylbenzene-2,4,6-triyl)tri-p-cresol, manufactured by BASF), Irganox 3114 (Irganox 1010: pentaerythritol tetra[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate ... 3114: 1,3,5-tris(3,5-di-tert-butyl-4-hydroxybenzyl)-1,3,5-triazine-2,4,6(1H,3H,5H)-trione, manufactured by BASF; Irganox 3125 (Irganox 3125, manufactured by BASF); ADK STAB AO-60 (pentaerythritol tetra[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate], manufactured by ADEKA company); ADK STAB AO-80 (3,9-bis{2-[3-(3-tert-butyl-4-hydroxy-5-methylphenyl)propionyloxy]-1,1-dimethylethyl}-2,4,8,10-tetraoxellaspiro[5,5]undecane, manufactured by ADEKA company); Sumilizer BHT (Sumilizer BHT (manufactured by Sumitomo Chemical Co., Ltd.), Cyanox 1790 (manufactured by Cytec Industries Inc.), Sumilizer GA-80 (manufactured by Sumitomo Chemical Co., Ltd.), Sumilizer GS (Sumilizer GS: 2-[1-(2-hydroxy-3,5-di-tert-pentylphenyl)ethyl]-4,6-di-tert-pentylphenyl acrylate, manufactured by Sumitomo Chemical Co., Ltd.), Sumilizer GM (Sumilizer GM: 2-tert-butyl-4-methyl-6-(2-hydroxy-3-tert-butyl-5-methylbenzyl)phenyl acrylate, manufactured by Sumitomo Chemical Co., Ltd.), Vitamin E (manufactured by Eisai Co., Ltd.), etc.

[0479] Among these commercially available phenolic antioxidants, from the viewpoint of imparting thermal stability to the resin, Irganox 1010, ADK STAB AO-60, ADK STAB AO-80, Irganox 1076, and Sumilizer GS are preferred.

[0480] They can be used individually or in combination with two or more.

[0481] Furthermore, phosphorus-based antioxidants, as mentioned above, are not limited to the following substances; for example, tris(2,4-di-tert-butylphenyl) phosphite, bis(2,4-bis(1,1-dimethylethyl)-6-methylphenyl)ethyl phosphite, tetra(2,4-di-tert-butylphenyl)(1,1-biphenyl)-4,4'-dimethylbisphosphite, bis(2,4-di-tert-butylphenyl)pentaerythritol diphosphite, and bis(2,6-di-tert-butyl-4... (-methylphenyl) pentaerythritol diphosphite, bis(2,4-dicumylphenyl) pentaerythritol diphosphite, tetra(2,4-tert-butylphenyl)(1,1-biphenyl)-4,4'-diylbisphosphite, di-tert-butyl-m-tolylphosphite, 4-[3-[(2,4,8,10-tetra-tert-butyldibenzo[d,f][1,3,2]dioxanecycloheptene)-6-yloxy]propyl]-2-methyl-6-tert-butylphenol, etc.

[0482] Furthermore, commercially available phosphorus-based antioxidants can also be used as phosphorus-based antioxidants. As commercially available phosphorus-based antioxidants, they are not limited to substances such as Irgafos 168 (Irgafos 168: tris(2,4-di-tert-butylphenyl) phosphite, manufactured by BASF), Irgafos 12 (Irgafos 12: tris[2-[[2,4,8,10-tetra-tert-butyldibenzo[d,f][1,3,2]dioxanecyclohepten-6-yl]oxy]ethyl]amine, manufactured by BASF), Irgafos 38 (Irgafos 38: bis(2,4-bis(1,1-dimethylethyl)-6-methylphenyl) ethyl phosphite, manufactured by BASF), ADK STAB 329K (ADK STAB-229K, manufactured by ADEKA company), and ADK STAB PEP-36 (ADK STAB... PEP-36 (manufactured by ADEKA company), ADK STAB PEP-36A (manufactured by ADEKA company), ADK STAB PEP-8 (manufactured by ADEKA company), ADK STAB HP-10 (manufactured by ADEKA company), ADK STAB 2112 (manufactured by ADEKA company), ADK STAB 1178 (manufactured by ADEKA company), ADK STAB 1500 (manufactured by ADEKA company), Sandstab P-EPQ (manufactured by Clariant company), Weston 618 (manufactured by Weston company). 618 (manufactured by General Electric Company (GE)), Weston 619G (manufactured by General Electric Company (GE)), Ultranox 626 (manufactured by General Electric Company (GE)), Sumilizer GP (Sumilizer GP: 4-[3-[(2,4,8,10-tetra-tert-butyldibenzo[d,f][1,3,2]dioxanecycloheptene)-6-yloxy]propyl]-2-methyl-6-tert-butylphenol, manufactured by Sumitomo Chemical Co., Ltd.), HCA (9,10-dihydro-9-oxy-10-phosphorylphenanthrene-10-oxide, manufactured by Sanko Co., Ltd.), etc.

[0483] Among these commercially available phosphorus-based antioxidants, from the viewpoint of their effect on imparting thermal stability to the resin and their combined effect with various antioxidants, Irgafos 168, ADK STAB PEP-36, ADK STAB PEP-36A, ADK STAB HP-10, and ADK STAB 1178 are particularly preferred, with ADK STAB PEP-36A and ADK STAB PEP-36 being particularly preferred.

[0484] These phosphorus-based antioxidants can be used alone or in combination with two or more.

[0485] Furthermore, as a sulfur-based antioxidant, it is not limited to the following substances, for example, 2,4-bis(dodecylthiomethyl)-6-methylphenol (Irganox 1726, manufactured by BASF), 2,4-bis(octylthiomethyl)-6-methylphenol (Irganox 1520L, manufactured by BASF), 2,2-bis{[3-(dodecylthio)-1-oxypropoxy]methyl}propane-1,3-diylbis[3-dodecylthio]propionate (ADK STAB AO-412S, manufactured by ADEKA company), 2,2-bis{[3-(dodecylthio)-1-oxypropoxy]methyl}propane-1,3-diylbis[3-dodecylthio]propionate (KEMINOX PLS, manufactured by CHEMIPRO KASEI, Japan). (manufactured by KAISHA,LTD.), di(tridecyl)3,3'-thiodipropionate (AO-503, manufactured by ADEKA company), etc.

[0486] Among these commercially available sulfur antioxidants, ADK STAB AO-412S and KEMINOX PLS are preferred from the perspectives of their effect on imparting thermal stability to the resin, their synergistic effect with various antioxidants, and their operability.

[0487] These sulfur-based antioxidants can be used alone or in combination with two or more.

[0488] The amount of antioxidant is only required to achieve the effect of improving thermal stability. Since there are concerns that excessive content may cause problems such as exudation during processing, the amount of antioxidant is preferably 5 parts by weight or less, more preferably 3 parts by weight or less, even more preferably 1 part by weight or less, even more preferably 0.8 parts by weight or less, even more preferably 0.01 to 0.8 parts by weight, and particularly preferably 0.01 to 0.5 parts by weight, relative to 100 parts by weight of methacrylic resin.

[0489] Regarding the content of antioxidants, any amount sufficient to improve thermal stability is acceptable. When the content is excessive, problems such as exudation may occur during processing. Therefore, relative to 100% by mass of methacrylic resin, it is preferably 5% by mass or less, more preferably 3% by mass or less, even more preferably 1% by mass or less, even more preferably 0.8% by mass or less, even more preferably 0.01 to 0.8% by mass, and particularly preferably 0.01 to 0.5% by mass.

[0490] There are no particular limitations on the timing of adding antioxidants. Examples include: adding them after polymerization begins in the monomer solution before polymerization; adding them to the polymer solution after polymerization and mixing them before supplying them to the devolatilization process; adding them to the molten polymer after devolatilization and mixing them before granulation; and adding and mixing them during the melt extrusion of the devolatilized and granulated granules. From the viewpoint of preventing thermal degradation and discoloration during the devolatilization process, it is preferable to add the antioxidant to the polymer solution after polymerization and mixing it before the devolatilization process, and then supply it to the devolatilization process.

[0491] -Hindered amine light stabilizers-

[0492] The resin composition constituting the light guide component of this embodiment may contain a hindered amine light stabilizer.

[0493] Hindered amine light stabilizers are not particularly limited, but are preferably compounds containing three or more ring structures. Here, the ring structure is preferably at least one selected from the group consisting of aromatic rings, aliphatic rings, aromatic heterocycles, and non-aromatic heterocycles. When a compound has two or more ring structures, the ring structures may be the same or different from each other.

[0494] As a hindered amine light stabilizer, it is not limited to the following substances, for example, specifically, bis(1,2,2,6,6-pentamethyl-4-piperidinyl)[[3,5-bis(1,1-dimethylethyl)-4-hydroxyphenyl]methyl]butylmalonate, a mixture of bis(1,2,2,6,6-pentamethyl-4-piperidinyl) sebacate and methyl 1,2,2,6,6-pentamethyl-4-piperidinyl sebacate, and bis(2,2,6,6-tetramethyl-4-piperidinyl) Sebacic acid ester, N,N'-bis(2,2,6,6-tetramethyl-4-piperidinyl)-N,N'-dicarboxyhexanediamine, dibutylamine-1,3,5-triazine-N,N'-bis(2,2,6,6-tetramethyl-4-piperidinyl)-1,6-hexanediamine and N-(2,2,6,6-tetramethyl-4-piperidinyl)butylamine condensate, poly[{6-(1,1,3,3-tetramethylbutyl)amino-1,3,5-triazine-2,4-diyl}{(2,2,6,6- Tetramethyl-4-piperidinyl)imino} hexamethylene {(2,2,6,6-tetramethyl-4-piperidinyl)imino}, tetra(1,2,2,6,6-pentamethyl-4-piperidinyl)butane-1,2,3,4-tetracarboxylic acid ester, tetra(2,2,6,6-tetramethyl-4-piperidinyl)butane-1,2,3,4-tetracarboxylic acid ester, 1,2,2,6,6-pentamethyl-4-piperidinol and β,β,β',β'-tetramethyl-2,4,8,10-tetraoxazolo[5] [5.5]Reaction product of undecane-3,9-diethanol, 2,2,6,6-tetramethyl-4-piperidinol and β,β,β',β'-tetramethyl-2,4,8,10-tetraoxazolo[5.5]undecane-3,9-diethanol, bis(1-undecoxy-2,2,6,6-tetramethylpiperidin-4-yl) carbonate, 1,2,2,6,6-pentamethyl-4-piperidinyl methacrylate, 2,2,6,6-tetramethyl-4-piperidinyl methacrylate, etc.

[0495] Among these, preferred compounds containing three or more ring structures include bis(1,2,2,6,6-pentamethyl-4-piperidinyl)[[3,5-bis(1,1-dimethylethyl)-4-hydroxyphenyl]methyl]butyl malonate, dibutylamine-1,3,5-triazine-N,N'-bis(2,2,6,6-tetramethyl-4-piperidinyl)-1,6-hexanediamine and N-(2,2,6,6-tetramethyl-4-piperidinyl)butylamine, and poly[{6-(1,1,3,3-tetramethylbutyl)amino-1,3,5-triazine-2,4- Dimethyl {(2,2,6,6-tetramethyl-4-piperidinyl)imino} hexamethylene {(2,2,6,6-tetramethyl-4-piperidinyl)imino}, the reaction product of 1,2,2,6,6-pentamethyl-4-piperidinol with β,β,β',β'-tetramethyl-2,4,8,10-tetraoxaspiro[5.5]undecane-3,9-diethanol, and the reaction product of 2,2,6,6-tetramethyl-4-piperidinol with β,β,β',β'-tetramethyl-2,4,8,10-tetraoxaspiro[5.5]undecane-3,9-diethanol.

[0496] The content of the hindered amine light stabilizer is only required to achieve the effect of improving light stability. Since excessive content may cause problems such as exudation during processing, the content is preferably 5% by mass or less, more preferably 3% by mass or less, further preferably 1% by mass or less, even more preferably 0.8% by mass or less, even more preferably 0.01 to 0.8% by mass, and particularly preferably 0.01 to 0.5% by mass, relative to 100% by mass of the methacrylic resin.

[0497] -UV absorber-

[0498] The resin composition may contain a UV absorber.

[0499] There are no particular limitations on the type of ultraviolet absorber, but it is preferred to use an ultraviolet absorber with a maximum absorption wavelength in the range of 280 to 380 nm. Examples of ultraviolet absorbers include benzotriazole compounds, benzotriazine compounds, benzophenone compounds, oxobenzophenone compounds, benzoic acid ester compounds, phenolic compounds, oxazole compounds, cyanoacrylate compounds, and benzoxazinone compounds.

[0500] Examples of benzotriazole compounds include 2,2'-methylenebis[4-(1,1,3,3-tetramethylbutyl)-6-(2H-benzotriazole-2-yl)phenol], 2-(3,5-di-tert-butyl-2-hydroxyphenyl)-5-chlorobenzotriazole, 2-(2H-benzotriazole-2-yl)-p-cresol, 2-(2H-benzotriazole-2-yl)-4,6-bis(1-methyl-1-phenylethyl)phenol, 2-benzotriazole-2-yl-4,6-di-tert-butylphenol, 2-[5-chloro(2H)-benzotriazole-2-yl]-4-methyl-6-tert-butylphenol, 2-(2H-benzotriazole-2-yl)-4,6-di-tert-butylphenol, 2-(2H-benzotriazole-2-yl)-4-(1,1,3-tetramethylbutyl)phenol, and 2-(2H-benzotriazole-2-yl)-4-(1,1,3-tetramethylbutyl)phenol. 3,3-Tetramethylbutyl)phenol, 2-(2H-benzotriazol-2-yl)-4-methyl-6-(3,4,5,6-tetrahydrophthalimidemethyl)phenol, reaction product of 3-(3-(2H-benzotriazol-2-yl)-5-tert-butyl-4-hydroxyphenyl)methyl propionate / polyethylene glycol 300, 2-(2H-benzotriazol-2-yl)-6-(linear and side-chain dodecyl)-4-methylphenol, 2-(5-methyl-2-hydroxyphenyl)benzotriazole, 2-[2-hydroxy-3,5-bis(α,α-dimethylbenzyl)phenyl]-2H-benzotriazole, 3-(2H-benzotriazol-2-yl)-5-(1,1-dimethylethyl)-4-hydroxy-C7-9 side-chain and linear alkyl esters.

[0501] Among them, benzotriazole compounds with a molecular weight of 400 or more are preferred. For example, commercially available products include Kemisorb 2792 (manufactured by CHEMIPRO, Japan), ADK STAB LA31 (manufactured by ADEKA company), and TINUVIN 234 (manufactured by BASF).

[0502] Examples of benzotriazine compounds include 2-mono(hydroxyphenyl)-1,3,5-triazine compounds, 2,4-bis(hydroxyphenyl)-1,3,5-triazine compounds, and 2,4,6-tris(hydroxyphenyl)-1,3,5-triazine compounds. Specifically, examples include 2,4-diphenyl-6-(2-hydroxy-4-methoxyphenyl)-1,3,5-triazine, 2,4-diphenyl-6-(2-hydroxy-4-ethoxyphenyl)-1,3,5-triazine, 2,4-diphenyl-(2-hydroxy-4-propoxyphenyl)-1,3,5-triazine, 2,4-diphenyl-(2-hydroxy-4-butoxyphenyl)-1,3,5-triazine, and 2,4-diphenyl-6-(2-hydroxy-4-butoxyphenyl)-1,3,5-triazine. 2,4-Diphenyl-6-(2-hydroxy-4-hexyloxyphenyl)-1,3,5-triazine, 2,4-Diphenyl-6-(2-hydroxy-4-octyloxyphenyl)-1,3,5-triazine, 2,4-Diphenyl-6-(2-hydroxy-4-dodecyloxyphenyl)-1,3,5-triazine, 2,4-Diphenyl-6-(2-hydroxy-4-benzyloxyphenyl)-1,3,5-triazine, 2,4-Diphenyl-6-(2-hydroxy-4-butoxyethoxy)-1,3,5-triazine, 2,4-bis(2-hydroxy-4-butoxyphenyl)-6-(2,4-dibutoxyphenyl)-1,3,5-triazine, 2,4,6-tris(2-hydroxy-4-methoxyphenyl) 2,4,6-Tris(2-hydroxy-4-ethoxyphenyl)-1,3,5-triazine, 2,4,6-Tris(2-hydroxy-4-propoxyphenyl)-1,3,5-triazine, 2,4,6-Tris(2-hydroxy-4-butoxyphenyl)-1,3,5-triazine, 2,4,6-Tris(2-hydroxy-4-butoxyphenyl)-1,3,5-triazine, 2,4,6-Tris(2-hydroxy-4-hexyloxyphenyl)-1,3,5-triazine, 2,4,6-Tris(2-hydroxy-4-octyloxyphenyl)-1,3,5-triazine, 2,4,6-Tris(2-hydroxy-4-dodecyloxyphenyl)-1,3,5-triazine, 2,4,6-Tris(2-hydroxy-4-benz ... Triazine, 2,4,6-tris(2-hydroxy-4-ethoxyethoxyphenyl)-1,3,5-triazine, 2,4,6-tris(2-hydroxy-4-butoxyethoxyphenyl)-1,3,5-triazine, 2,4,6-tris(2-hydroxy-4-propoxyethoxyphenyl)-1,3,5-triazine, 2,4,6-tris(2-hydroxy-4-methoxycarbonylpropoxyphenyl)-1,3,5-triazine, 2,4,6-tris(2-hydroxy-4-ethoxycarbonylethoxyphenyl)-1,3,5-triazine, 2,4,6-tris(2-hydroxy-4-ethoxycarbonylethoxyphenyl)-1,3,5-triazine, 2,4,6-tris(2-hydroxy-4-(1-(2-ethoxyhexyloxy)-1-oxopropane-2-yloxy)phenyl)-1,3,5-triazine, 2,4,6-Tris(2-hydroxy-3-methyl-4-methoxyphenyl)-1,3,5-triazine, 2,4,6-tris(2-hydroxy-3-methyl-4-ethoxyphenyl)-1,3,5-triazine, 2,4,6-tris(2-hydroxy-3-methyl-4-propoxyphenyl)-1,3,5-triazine, 2,4,6-tris(2-hydroxy-3-methyl-4-butoxyphenyl)-1,3,5-triazine, 2,4,6- Tris(2-hydroxy-3-methyl-4-butoxyphenyl)-1,3,5-triazine, 2,4,6-tris(2-hydroxy-3-methyl-4-hexyloxyphenyl)-1,3,5-triazine, 2,4,6-tris(2-hydroxy-3-methyl-4-octyloxyphenyl)-1,3,5-triazine, 2,4,6-tris(2-hydroxy-3-methyl-4-dodecyloxyphenyl)-1,3,5-triazine, 2,4,6- Tris(2-hydroxy-3-methyl-4-benzyloxyphenyl)-1,3,5-triazine, 2,4,6-tris(2-hydroxy-3-methyl-4-ethoxyethoxyphenyl)-1,3,5-triazine, 2,4,6-tris(2-hydroxy-3-methyl-4-butoxyethoxyphenyl)-1,3,5-triazine, 2,4,6-tris(2-hydroxy-3-methyl-4-propoxyethoxyphenyl)-1,3,5-triazine 2,4,6-Tris(2-hydroxy-3-methyl-4-methoxycarbonylpropyloxyphenyl)-1,3,5-triazine, 2,4,6-Tris(2-hydroxy-3-methyl-4-ethoxycarbonylethyloxyphenyl)-1,3,5-triazine, 2,4,6-Tris(2-hydroxy-3-methyl-4-(1-(2-ethoxyhexyloxy)-1-oxopropane-2-yloxy)phenyl)-1,3,5-triazine, etc.

[0503] As benzotriazine compounds, commercially available products can be used, such as Kemisorb 102 (manufactured by CHEMIPRO, Japan), LA-F70 (manufactured by ADEKA company), LA-46 (manufactured by ADEKA company), TINUVIN405 (manufactured by BASF), TINUVIN460 (manufactured by BASF), TINUVIN479 (manufactured by BASF), and TINUVIN1577FF (manufactured by BASF).

[0504] From the viewpoint of high compatibility with acrylic resins and excellent ultraviolet absorption characteristics, ultraviolet absorbers having a 2,4-bis(2,4-dimethylphenyl)-6-[2-hydroxy-4-(3-alkyloxy-2-hydroxypropyloxy)-5-α-cumylphenyl]-s-triazine skeleton ("alkoxy" refers to long-chain alkoxy such as octoxy, nonoxy, and decoxy) are further preferred.

[0505] As ultraviolet absorbers, benzotriazole compounds and benzotriazine compounds with a molecular weight of 400 or more are preferred, especially from the viewpoint of compatibility with resin and volatility upon heating. Furthermore, benzotriazine compounds are particularly preferred from the viewpoint of suppressing the decomposition of the ultraviolet absorber itself due to heating during extrusion processing.

[0506] In addition, the melting point (Tm) of the above-mentioned ultraviolet absorber is preferably 80°C or higher, more preferably 100°C or higher, even more preferably 130°C or higher, and even more preferably 160°C or higher.

[0507] For the ultraviolet absorber, the weight reduction rate when heated from 23°C to 260°C at a rate of 20°C / min is preferably 50% or less, more preferably 30% or less, even more preferably 15% or less, even more preferably 10% or less, and even more preferably 5% or less.

[0508] These ultraviolet absorbers can be used alone or in combination of two or more. By combining two ultraviolet absorbers with different structures, it is possible to absorb ultraviolet light over a wide wavelength range.

[0509] The content of the ultraviolet absorber is not particularly limited, as long as it does not hinder the heat resistance, damp heat resistance, thermal stability, and molding processability, and is sufficient to achieve the effects of the present invention. It is preferably 0.1 to 5 parts by weight, more preferably 0.2 to 4 parts by weight, more preferably 0.25 to 3 parts by weight, and even more preferably 0.3 to 3 parts by weight, relative to 100 parts by weight of the methacrylic resin. Within this range, the ultraviolet absorption performance and molding properties are well-balanced.

[0510] -Mold Release Agent-

[0511] The resin composition may contain a release agent. The release agent is not limited to substances such as fatty acid esters, fatty acid amides, fatty acid metal salts, hydrocarbon lubricants, alcohol lubricants, polyalkylene glycols, carboxylic acid esters, and hydrocarbon paraffinic mineral oils.

[0512] There are no particular limitations on the fatty acid esters that can be used as the aforementioned release agent; any previously known substances can be used.

[0513] As fatty acid esters, for example, ester compounds can be made of fatty acids with 12 to 32 carbon atoms, such as lauric acid, palmitic acid, heptadecanic acid, stearic acid, oleic acid, arachidic acid, and behenic acid, with monoaliphatic alcohols such as palmitol, stearyl alcohol, and behenicol, as well as polyaliphatic alcohols such as glycerol, pentaerythritol, dipentaerythritol, and sorbitan; and complex ester compounds of fatty acids and polyaliphatic organic acids with monoaliphatic alcohols or polyaliphatic alcohols.

[0514] Examples of such fatty acid ester-based lubricants include cetyl palmitate, butyl stearate, stearyl stearate, stearyl citrate, glyceryl monocaprylate, glyceryl monodecanoate, glyceryl monolaurate, glyceryl monopalmitate, glyceryl dipalmitate, glyceryl monostearate, glyceryl distearate, glyceryl tristearate, glyceryl monooleate, glyceryl dioleate, glyceryl trioleate, glyceryl monolinoleate, glyceryl monobehenate, glyceryl mono-12-hydroxystearate, glyceryl di-12-hydroxystearate, glyceryl tri-12-hydroxystearate, glyceryl diacetyl monostearate, glyceryl citrate fatty acid ester, pentaerythritol adipate stearate, partially saponified lignite ester, pentaerythritol tetrastearate, dipentaerythritol hexastearate, and sorbitan tristearate.

[0515] These fatty acid ester lubricants can be used alone or in combination of two or more.

[0516] As commercially available products, examples include the RIKEMAL series, POEM series, RIKESTER series, and RIKEMASTER series manufactured by Riken Vitamin Co., Ltd.; and the EXCEL series, RHEODOL series, EXCEPARL series, and COCONARD series manufactured by Kao Corporation. More specifically, examples include RIKEMAL S-100, RIKEMAL H-100, POEM V-100, RIKEMALB-100, RIKEMAL HC-100, RIKEMAL S-200, POEM B-200, RIKESTER EW-200, RIKESTER EW-400, EXCEL S-95, and RHEODOL MS-50.

[0517] There are no particular restrictions on fatty acid amides; previously known fatty acid amides can be used.

[0518] Examples of fatty acid amides include, for instance, saturated fatty acid amides such as lauryl amide, palmitamide, stearamide, behenamide, and hydroxystearamide; unsaturated fatty acid amides such as oleamide, erucamide, and castor oil amide; substituted amides such as N-stearylstearamide, N-oleyloleamide, N-stearyloleamide, N-oleylstearamide, N-stearylerucamide, and N-oleylpalmitamide; hydroxymethyl amides such as hydroxymethylstearamide and hydroxymethylbehenamide; and methylene bis-stearamide, ethylene bis-decanoamide, ethylene bis-laurateamide, and ethylene bis-stearamide (ethylene bis-stearamide). Dimethyl bis(stearyl)amide, ethylene bis(isostearyl)amide, ethylene bis(hydroxystearyl)amide, ethylene bis(benzyl)amide, hexamethylene bis(stearyl)amide, hexamethylene bis(benzyl)amide, hexamethylene bis(hydroxystearyl)amide, N,N'-distearate adipamide, N,N'-distearate sebacic acid amide, and other saturated fatty acid diamides; ethylene bis(oleyl)amide, hexamethylene bis(oleyl)amide, N,N'-dioleyl adipamide, N,N'-dioleyl sebacic acid amide, and other unsaturated fatty acid diamides; m-xylene bis(stearyl)amide, N,N'-distearate isophthalic acid amide, and other aromatic diamides, etc.

[0519] These fatty acid amides can be used alone or in combination of two or more.

[0520] As commercially available products, examples include the DIAMIDO series (manufactured by Nippon Chemical Co., Ltd.), the Amide series (amide series) (manufactured by Nippon Chemical Co., Ltd.), the Nikka Amide series (manufactured by Nippon Chemical Co., Ltd.), the hydroxymethylamide series, the diamide series, the SLIPAX series (manufactured by Nippon Chemical Co., Ltd.), the Kao wax series (manufactured by Kao Corporation), the fatty acid amide series (manufactured by Kao Corporation), and the ethylene bis-stearamide series (manufactured by Daiichi Chemical Co., Ltd.).

[0521] Fatty acid metal salts refer to metal salts of higher fatty acids, such as lithium stearate, magnesium stearate, calcium stearate, calcium laurate, calcium ricinoleate, strontium stearate, barium stearate, barium laurate, barium ricinoleate, zinc stearate, zinc laurate, zinc ricinoleate, zinc 2-ethylhexanoate, lead stearate, dilead stearate, lead naphthenate, calcium 12-hydroxystearate, lithium 12-hydroxystearate, etc. Among them, calcium stearate, magnesium stearate, and zinc stearate are particularly preferred from the perspective of excellent processability and extremely excellent transparency of the obtained transparent resin composition.

[0522] As commercially available products, examples include the SZ series, SC series, SM series, and SA series manufactured by Sakai Chemical Industry Co., Ltd.

[0523] From the viewpoint of maintaining transparency, the content of the above-mentioned fatty acid metal salt is preferably 0.2% by mass or less relative to 100% by mass of the resin composition.

[0524] The above-mentioned release agents can be used alone or in combination with two or more.

[0525] As a release agent for use, it is preferred to have a decomposition start temperature of 200°C or higher. Here, the decomposition start temperature can be determined by the 1% mass loss temperature based on TGA.

[0526] Regarding the content of the release agent, any amount sufficient to achieve the desired effect is acceptable. Excessive content may lead to problems such as seepage during processing and poor extrusion due to screw slippage. Therefore, relative to 100% by mass of the methacrylic resin, it is preferably 5% by mass or less, more preferably 3% by mass or less, further preferably 1% by mass or less, even more preferably 0.8% by mass or less, even more preferably 0.01 to 0.8% by mass, and particularly preferably 0.01 to 0.5% by mass. Adding an amount within the above range tends to suppress poor demolding during injection molding, while also suppressing the decrease in transparency caused by the addition of the release agent. Therefore, this is preferable.

[0527] The amount of mold release agent should be sufficient to achieve the desired effect. Excessive amounts may cause problems such as seepage during processing and poor extrusion due to screw slippage. Therefore, relative to 100 parts by weight of methacrylic resin, the amount of mold release agent is preferably 5 parts by weight or less, more preferably 3 parts by weight or less, further preferably 1 part by weight or less, even more preferably 0.8 parts by weight or less, even more preferably 0.01 to 0.8 parts by weight, and particularly preferably 0.01 to 0.5 parts by weight. Adding an amount within the above range not only suppresses the reduction in transparency caused by the addition of mold release agent but also tends to suppress poor demolding during injection molding.

[0528] In mold release agents where concerns such as seepage during processing and poor extrusion due to screw slippage cannot be resolved even with increased release agent content, their effects as plasticizers can be expected by increasing their addition amount. Specifically, it is possible to prepare resin compositions that contribute to improved flowability during molding, excellent formability of thin-walled molded sheets, and excellent transferability of fine shapes. Furthermore, when performing an annealing process to reduce residual stress in the molded article, if the melting point Tm of the release agent is in a temperature range 30 to 80°C lower than the Tg of the resin composition, annealing at a temperature of approximately Tg-35 to 50°C allows the release agent to function within the same temperature range to promote stress relief, thereby reducing residual stress. Furthermore, by performing the annealing process in a temperature range sufficiently lower than the Tg of the resin composition, it is possible to obtain light guide components that suppress shape deformation of the molded article, maintain surface accuracy after molding, and have good surface accuracy.

[0529] (Other thermoplastic resins)

[0530] Without prejudice to the purpose of the present invention, the resin composition constituting the light guide component of this embodiment may also include other thermoplastic resins besides methacrylic resins for the purpose of adjusting birefringence and improving flexibility.

[0531] Other thermoplastic resins include, for example, polyacrylates such as polybutyl acrylate; styrene-based polymers such as polystyrene, styrene-butyl acrylate copolymers, styrene-acrylonitrile copolymers, and acrylonitrile-butadiene-styrene block copolymers; in addition, examples include acrylic rubber particles with a 3- to 4-layer structure disclosed in Japanese Patent Application Publication Nos. 59-202213, 63-27516, 51-129449, and 52-56150; rubber polymers disclosed in Japanese Patent Application Publication Nos. 60-17406 and 8-245854; and graft copolymer particles containing methacrylic acid rubber obtained by multi-stage polymerization disclosed in International Publication No. 2014-002491.

[0532] From the viewpoint of obtaining good optical and mechanical properties, styrene-acrylonitrile copolymers and rubber-containing graft copolymer particles with grafted portions on the surface layer are preferred, wherein the grafted portions are composed of a composition that is compatible with a methacrylic resin containing a structural unit (X) having a ring structure in the main chain.

[0533] From the viewpoint of improving the impact strength and optical properties of the molded articles obtained from the composition of this embodiment, the average particle size of the aforementioned acrylic rubber particles, methacrylic rubber graft copolymer particles, and rubber polymer is preferably 0.03 to 1 μm, and more preferably 0.05 to 0.5 μm.

[0534] As for the content of other thermoplastic resins, when the methacrylic resin is set to 100 parts by weight, it is preferably 0 to 50 parts by weight, and more preferably 0 to 25 parts by weight.

[0535] (Higher fatty acid esters)

[0536] The preferred resin composition contains higher fatty acid esters.

[0537] By adding a specific amount of higher fatty acid esters to the resin composition, the target function of the present invention can be exhibited.

[0538] Furthermore, for the aforementioned higher fatty acid esters, it is preferable to use higher fatty acid esters having two or fewer hydroxyl groups within the molecule. This is because it is possible to obtain optical components with low haze and good optical properties.

[0539] Furthermore, the content of higher fatty acid esters in the resin composition is preferably 0.5% by mass or more and 2.8% by mass or less, more preferably 0.6% by mass or more and 2.5% by mass or less, even more preferably 0.7% by mass or more and 1.7% by mass or less, and even more preferably 0.8% by mass or more and 1.3% by mass or less.

[0540] By mixing the higher fatty acid esters within the aforementioned range, the resin's fluidity is drastically improved and orientation birefringence is mitigated. Furthermore, only the higher fatty acids act at temperatures near their melting points, thereby promoting the mitigation of resin side chains and mitigating internal deformation. The surface shape is not deteriorated during the annealing process, and internal deformation is preferentially reduced only.

[0541] Furthermore, by controlling the dosage of the higher fatty acid ester within the aforementioned range, foreign matter such as white fog and poor appearance during molding can be suppressed, maintaining high shape accuracy of the molded product. Additionally, it can suppress contamination of the mold insert surface and blockage of the exhaust port during molding.

[0542] It should be noted that the description of higher fatty acid esters can refer to the record in the (higher fatty acid esters) section described later.

[0543] <Cyclic olefin copolymer resin composition>

[0544] The resin composition constituting the light guide component of this embodiment is preferably a cyclic olefin copolymer resin composition.

[0545] Cyclic olefin copolymer resin compositions are resin compositions comprising copolymers of ethylene or α-olefins with cyclic olefins, i.e., cyclic olefin copolymers (hereinafter, sometimes referred to as "cyclic olefin copolymer resins").

[0546] (Cyclic olefin copolymer)

[0547] In this embodiment, the cyclic olefin copolymer, whose main chain ring structure includes cyclic olefins, comprises copolymers in which structural units from cyclic olefins are required structural units.

[0548] The cyclic olefin copolymer is preferably a copolymer of ethylene or α-olefin with a cyclic olefin.

[0549] Preferably, the cyclic olefin copolymer resin composition of this embodiment contains a structural unit (b) of at least one cyclic olefin selected from the group consisting of structural units represented by general formula (II), general formula (III), and general formula (IV). From the viewpoint of being able to maintain a good balance between the transparency and refractive index of the obtained molded article and further improve heat resistance or improve moldability, it is more preferable to contain a structural unit (a) of at least one olefin represented by general formula (I) and a structural unit (b) of at least one cyclic olefin selected from the group consisting of structural units represented by general formula (II), general formula (III), and general formula (IV).

[0550]

[0551] In the above general formula (I), R 300 A straight-chain or branched hydrocarbon group representing 1 to 29 hydrogen or carbon atoms.

[0552]

[0553] In the above general formula (II), u is 0 or 1, v is 0 or a positive integer, preferably an integer greater than or equal to 0 and less than or equal to 2, more preferably 0 or 1, w is 0 or 1, and R 61 ~R 78 and R a1 and R b1 They can be the same or different from each other, and can be hydrogen atoms, halogen atoms, alkyl groups with 1 to 20 carbon atoms, haloalkyl groups with 1 to 20 carbon atoms, cycloalkyl groups with 3 to 15 carbon atoms, or aromatic hydrocarbon groups with 6 to 20 carbon atoms, R 75 ~R 78 They may bond with each other to form a single ring or multiple rings, or they may not bond with each other.

[0554]

[0555] In the above general formula (III), x and d are integers of 0 or 1 or higher, preferably integers of 0 or higher and less than 2, more preferably 0 or 1, y and z are 0, 1 or 2, and R 81 ~R 99 They can be the same or different from each other, consisting of hydrogen atoms, halogen atoms, alkyl groups with 1 to 20 carbon atoms or cycloalkyl groups with 3 to 15 carbon atoms (i.e., aliphatic hydrocarbon groups), aromatic hydrocarbon groups with 6 to 20 carbon atoms or alkoxy groups, R 89 and R 90 Bonded carbon atoms and R 93 Bonded carbon atoms or R 91 The bonded carbon atoms can be directly bonded or bonded via alkylene groups having 1 to 3 carbon atoms. Additionally, when y = z = 0, R... 95 With R 92 Or R 95 With R 99 They may bond with each other to form monocyclic or polycyclic aromatic rings, or they may not bond with each other.

[0556]

[0557] In the above general formula (IV), R 100 R 101 They can be the same or different from each other, representing hydrocarbon groups with 1 to 5 hydrogen or carbon atoms, where f is 1 ≤ f ≤ 18.

[0558] (Olefin monomers)

[0559] The olefin monomers, which are one of the copolymerization raw materials of the cyclic olefin copolymer in this embodiment, are added to copolymerize to form a structural unit represented by the above general formula (I).

[0560] Specifically, an olefin monomer represented by the following general formula (Ia) corresponding to the above general formula (I) is used.

[0561]

[0562] In the above general formula (Ia), R 300 A straight-chain or branched hydrocarbon group representing 1 to 29 hydrogen or carbon atoms.

[0563] Examples of olefin monomers represented by the above general formula (Ia) include ethylene or α-olefins. Specifically, examples include ethylene, propylene, 1-butene, 1-pentene, 1-hexene, 3-methyl-1-butene, 3-methyl-1-pentene, 3-ethyl-1-pentene, 4-methyl-1-pentene, 4-methyl-1-hexene, 4,4-dimethyl-1-hexene, 4,4-dimethyl-1-pentene, 4-ethyl-1-hexene, 3-ethyl-1-hexene, 1-octene, 1-decene, 1-dodecene, 1-tetradecene, 1-hexadecene, 1-octadecene, and 1-eicosene. From the viewpoint of obtaining molded articles with superior heat resistance, mechanical properties, and optical properties, ethylene or propylene is preferred, and ethylene is particularly preferred. Two or more olefin monomers represented by the above general formula (Ia) may be used.

[0564] In this embodiment, when all structural units constituting the cyclic olefin copolymer are set to 100 mol%, the proportion of structural units from olefins is preferably 5 mol% or more and 95 mol% or less, more preferably 40 mol% or more and 85 mol% or less, further preferably 50 mol% or more and 64 mol% or less, and particularly preferably 50 mol% or more and 62 mol% or less.

[0565] It should be noted that the proportion of structural units from olefins can be determined by... 13 C-NMR determination.

[0566] (Cyclic olefin monomers)

[0567] There is no particular limitation on the cyclic olefin monomers constituting the cyclic olefin copolymer resin. For example, the cyclic olefin monomers described in paragraphs

[0037] to

[0063] of International Publication No. 2006 / 0118261 can be cited.

[0568] Preferably, the cyclic olefin monomer, which is one of the copolymerization raw materials for the cyclic olefin copolymer of this embodiment, is added copolymerized to form a structural unit (b) of a cyclic olefin represented by the above general formula (II), the above general formula (III), or the above general formula (IV). Specifically, cyclic olefin monomers represented by general formulas (IIa), (IIIa), and (IVa), which correspond to the above general formulas (II), (III), and (IV), respectively, are used.

[0569]

[0570] In the above general formula (IIa), u is 0 or 1, v is 0 or a positive integer, preferably an integer greater than or equal to 0 and less than or equal to 2, more preferably 0 or 1, w is 0 or 1, and R 61 ~R 78 and R a1 and Rb1 They can be the same or different from each other, and can be hydrogen atoms, halogen atoms, alkyl groups with 1 to 20 carbon atoms, haloalkyl groups with 1 to 20 carbon atoms, cycloalkyl groups with 3 to 15 carbon atoms, or aromatic hydrocarbon groups with 6 to 20 carbon atoms, R 75 ~R 78 They may bond with each other to form a single ring or multiple rings, or they may not bond with each other.

[0571]

[0572] In the above general formula (IIIa), x and d are integers of 0 or 1 or higher, preferably integers of 0 or higher and less than 2, more preferably 0 or 1, y and z are 0, 1 or 2, and R 81 ~R 99 They can be the same or different from each other, consisting of hydrogen atoms, halogen atoms, alkyl groups with 1 to 20 carbon atoms or cycloalkyl groups with 3 to 15 carbon atoms (i.e., aliphatic hydrocarbon groups), aromatic hydrocarbon groups with 6 to 20 carbon atoms or alkoxy groups, R 89 and R 90 Bonded carbon atoms and R 93 Bonded carbon atoms or R 91 The bonded carbon atoms can be directly bonded or bonded via alkylene groups having 1 to 3 carbon atoms. Additionally, when y = z = 0, R... 95 With R 92 Or R 95 With R 99 They may bond with each other to form monocyclic or polycyclic aromatic rings, or they may not bond with each other.

[0573]

[0574] In the above general formula (IVa), R 100 and R 101 They can be the same or different from each other, representing hydrocarbon groups with 1 to 5 hydrogen or carbon atoms, where f is 1 ≤ f ≤ 18.

[0575] As a copolymer component, the cyclic olefin copolymer (A) has improved solubility in solvents by using olefin monomers represented by the above general formula (Ia) and cyclic olefin monomers represented by general formulas (IIa), (IIIa) or (IVa), thus resulting in good moldability and improved product yield.

[0576] For specific examples of cyclic olefin monomers represented by general formulas (IIa), (IIIa) or (IVa), compounds described in paragraphs

[0037] to

[0063] of International Publication No. 2006 / 0118261 can be used.

[0577] Specifically, examples include bicyclic-2-heptene derivatives (bicyclic hept-2-ene derivatives), tricyclic-3-decene derivatives, tricyclic-3-undecene derivatives, tetracyclic-3-dodecene derivatives, pentacyclic-4-pentadecaene derivatives, pentacyclic pentadecadiene derivatives, pentacyclic-3-pentadecaene derivatives, pentacyclic-4-hexadecene derivatives, pentacyclic-3-hexadecene derivatives, hexacyclic-4-heptadecene derivatives, and heptacyclic-5-eicosene derivatives. Compounds, heptacyclic-4-eicosene derivatives, heptacyclic-5-docosene derivatives, octacyclic-5-docosene derivatives, nonacyclic-5-pentacyclic derivatives, nonacyclic-6-hexacyclic derivatives, cyclopentadiene-acenaphthene adducts, 1,4-methylene-1,4,4a,9a-tetrahydrofluorene derivatives, 1,4-methylene-1,4,4a,5,10,10a-hexahydroanthracene derivatives, and cycloalkylene derivatives with 3 to 20 carbon atoms.

[0578] Furthermore, among the cyclic olefin monomers represented by general formula (IIa), (IIIa) or (IVa), the cyclic olefin monomer represented by general formula (IIa) is preferred.

[0579] As the cyclic olefin monomer represented by the above general formula (IIa), bicyclo[2.2.1]-2-heptene (also known as "norbornene") and tetracyclo[4.4.0.1]-2-heptene are preferred. 2，5 1. 7，10 ]-3-Dodecene (also known as tetracyclododecene), more preferably tetracyclo[4.4.0.1] 2，5 1. 7，10 ]-3-Dodecene. These cyclic olefins have a rigid ring structure, and therefore have the advantage of easily maintaining the elastic modulus of copolymers and molded articles.

[0580] When all structural units constituting the main chain of the cyclic olefin copolymer are set to 100 mol%, the proportion of structural units (cyclic skeleton structural units) from the cyclic olefin monomer is preferably 5 mol% or more and 95 mol% or less, more preferably 15 mol% or more and 60 mol% or less, further preferably 36 mol% or more and 50 mol% or less, and particularly preferably 38 mol% or more and 50 mol% or less.

[0581] By using structural units derived from cyclic olefin monomers within the aforementioned range, it exhibits high heat resistance and maintains a high elastic modulus, particularly in high-temperature regions. This enables the suppression of shape deformation caused by the annealing process, thereby minimizing surface deformation of the light guide component of the present invention.

[0582] The molecular weight of the cyclic olefin copolymer in this embodiment is not particularly limited, but preferably the intrinsic viscosity [η] measured in naphthalene at 135°C shows a molecular weight of 0.03 dl / g to 10 dl / g, more preferably a molecular weight of 0.05 dl / g to 5 dl / g, and even more preferably a molecular weight of 0.10 dl / g to 2 dl / g.

[0583] If the molecular weight of the cyclic olefin copolymer is above the lower limit mentioned above, the mechanical strength of the molded article can be improved. Conversely, if the molecular weight is below the upper limit mentioned above, the moldability can be improved.

[0584] (Higher fatty acid esters)

[0585] Preferably, the cyclic olefin copolymer resin composition of this embodiment contains, in addition to the above-mentioned cyclic olefin copolymer, higher fatty acid esters.

[0586] The objective function of the present invention can be achieved by adding a specific amount of higher fatty acid esters to the cyclic olefin copolymer resin composition of this embodiment.

[0587] Furthermore, this is because, for the aforementioned higher fatty acid esters, it is preferable to use higher fatty acid esters with two or fewer hydroxyl groups in the molecule, which can yield optical components with low haze and good optical properties.

[0588] Furthermore, the content of higher fatty acid esters in the cyclic olefin copolymer resin composition of this embodiment is preferably 0.5% by mass or more and 2.8% by mass or less, more preferably 0.6% by mass or more and 2.5% by mass or less, even more preferably 0.7% by mass or more and 1.7% by mass or less, and even more preferably 0.8% by mass or more and 1.3% by mass or less.

[0589] By mixing the higher fatty acid esters within the aforementioned range, the resin's fluidity is drastically improved and orientation birefringence is mitigated. Furthermore, only the higher fatty acids act at temperatures near their melting points, thereby promoting the mitigation of resin side chains and mitigating internal deformation. The surface shape is not deteriorated during the annealing process, and internal deformation is preferentially reduced only.

[0590] Furthermore, by controlling the dosage of the higher fatty acid ester within the aforementioned range, foreign matter such as white fog and appearance defects during molding can be suppressed, maintaining high shape accuracy of the molded product. Moreover, it can also suppress contamination of the mold insert surface and blockage of the exhaust port during molding.

[0591] Here, the higher fatty acid ester is an ester compound composed of fatty acids having 6 or more carbon atoms and an alcohol. The higher fatty acid ester of this embodiment is composed of the following polyols and fatty acids.

[0592] Examples of such polyols include glycerol, pentaerythritol, diglycerol, triglycerol, polyglycerol, 1,2-ethylene glycol, dipentaerythritol, sorbitan, polyethylene glycol, polypropylene glycol, polybutanediol, α,α'-[(isopropylidene)bis-4,1-phenylene]bis{ω-hydroxy-poly[oxy(methylethylene)]}, polyoxyethylene-laurylamine, polyoxyethylene-stearylamine, polyoxyethylene-oleylamine, polyoxyethylene-polyoxypropylene pentaerythritol ether, and polyethylene glycol. Polybutylene glycol pentaerythritol ether, polyoxytetramethylene polyoxyethylene glycol, polyoxytetramethylene polyoxypropylene glycol, trimethylolpropane-tris(polyoxytetramethylene-polyoxypropylene) ether, polyoxyethylene-bisphenol A ether, polyoxypropylene-bisphenol A ether, polyoxyethylene-polyoxypropylene-bisphenol A ether, 1-thioglycerol, polyoxypropylene diglyceride, polyoxypropylene sorbitol, polyoxybutylene polyoxyethylene pentaerythritol ether, polyoxyethylene methyl glucoside, polyoxypropylene methyl glucoside, etc.

[0593] Examples of the fatty acids mentioned include saturated fatty acids such as hexanoic acid, heptanoic acid, caprylic acid, nonanoic acid, decanoic acid, lauric acid, myristic acid, palmitic acid, and stearic acid; monounsaturated fatty acids such as crotonic acid, myristoleic acid, palmitoleic acid, sapienic acid, oleic acid, transoleic acid, codoleic acid, and eicosapentaenoic acid; diunsaturated fatty acids such as linoleic acid, eicosapentaenoic acid, and docosahexaenoic acid; triunsaturated fatty acids such as linolenic acid, terpineic acid, tung oil acid, and eicosatrienoic acid; and tetraunsaturated fatty acids such as octadecanoic acid, arachidonic acid, and eicosapentaenoic acid.

[0594] Furthermore, for additives, considering the industrial singularity in synthesizing or obtaining higher fatty acid esters, polyols with high symmetry are preferred. Specifically, polyols with higher symmetry than C2 or C3 are preferred, more preferably polyols with higher polyol symmetry than C2 or C3 and without stereoisomers, and even more preferably polyols with higher polyol symmetry than C2 or C3 and all hydroxyl groups equivalent as polyols without stereoisomers, particularly pentaerythritol.

[0595] As described above, for the higher fatty acid ester, the number of OH groups (hydroxyl groups) within the molecule is preferably two or less. By using higher fatty acid esters with this molecular structure, good dispersion in the resin composition is maintained, and white turbidity, which is the main cause of haze deterioration, is less likely to occur. In addition, mold contamination caused by exudation during molding can be suppressed.

[0596] Furthermore, the melting point of the higher fatty acid ester is preferably above 0°C, more preferably above 10°C, even more preferably above 25°C, and particularly preferably above 35°C. Being in this temperature range, it is difficult for the temperature to decrease at room temperature, thus suppressing mold contamination and decreased mechanical strength caused by exudation during molding.

[0597] Furthermore, the melting point of the higher fatty acid ester is preferably 10°C or more lower than the glass transition temperature (Tg) of the resin composition of this embodiment (Tg-10°C or less), more preferably Tg-20°C, and particularly preferably Tg-30°C or less.

[0598] By placing the melting point of the higher fatty acid ester in such a temperature range, it is difficult to cause shape changes in the molded body in the high-temperature region where the main chain of the resin is moderate, thus suppressing mold contamination caused by exudation during molding.

[0599] Furthermore, in annealing processes at temperatures approximately 40°C lower than the glass transition temperature of the resin composition, while shape deformation of the molded article can be suppressed, the mitigation effect on birefringence is generally small. However, by using higher fatty acid esters with melting points within the aforementioned temperature range, which are above their melting points at the same temperature, they can function freely, promoting the mitigation of the ring backbone and side chains extending from the resin main chain, thereby effectively reducing birefringence.

[0600] (Other additives)

[0601] To the extent that it does not significantly impair the effects of the present invention, various additives may be included in the cyclic olefin copolymer resin composition of this embodiment as needed.

[0602] As for the additives mentioned, there are no particular limitations. In addition to the higher fatty acid esters, examples include, for instance, weather stabilizers, heat stabilizers, antioxidants, light stabilizers such as hindered amine light stabilizers, ultraviolet absorbers, release agents, lubricants, other thermoplastic resins other than cyclic olefin copolymers, metal passivators, hydrochloric acid absorbers, slip agents, anti-caking agents, anti-fogging agents, synthetic oils, paraffin wax, organopolysiloxanes, mineral oils and other softeners, plasticizers, flame retardants, antistatic agents, organic fibers, iron oxides and other pigments and other inorganic fillers, glass fibers, carbon fibers, metal whiskers and other reinforcing materials, colorants, phosphites, phosphonites, phosphates and other organophosphorus compounds, other additives, or mixtures thereof.

[0603] <Method for manufacturing resin composition>

[0604] As for the method of manufacturing the resin composition, there is no particular limitation as long as a resin composition that satisfies the requirements of the present invention can be obtained. For example, methods of mixing using a mixing machine such as an extruder, heated roller, kneader, drum mixer, or Banbury mixer can be cited. Among these, from a production perspective, it is preferable to use an extruder for mixing. As for the mixing temperature, it can be set according to the preferred processing temperature of the polymer constituting the methacrylic resin and the other resins mixed in; as a reference, it is in the range of 140 to 300°C, preferably in the range of 180 to 280°C. In addition, for the purpose of reducing volatile matter, it is preferable to provide an exhaust port on the extruder.

[0605] Here, in the resin composition of the substrate portion constituting the light guide component of this embodiment, the residual solvent amount (residual solvent amount) is preferably less than 1000 ppm by mass, more preferably less than 800 ppm by mass, and even more preferably less than 700 ppm by mass.

[0606] Here, residual solvent refers to the polymerization solvent used during polymerization (excluding alcohols) and the solvent used when redissolving the resin obtained through polymerization. Specifically, examples of polymerization solvents include aromatic hydrocarbons such as toluene, xylene, ethylbenzene, and cumene; ketones such as methyl isobutyl ketone, butyl cellosolve, methyl ethyl ketone, and cyclohexanone; and polar solvents such as dimethylformamide and 2-methylpyrrolidone. Examples of solvents used for redissolution include toluene, methyl ethyl ketone, and dichloromethane.

[0607] The residual alcohol content (residual alcohol content) of the resin composition is preferably less than 500 ppm by mass, more preferably less than 400 ppm by mass, and even more preferably less than 350 ppm by mass.

[0608] Here, residual alcohols refer to alcohols produced as byproducts of cyclization condensation reactions. Specifically, examples include aliphatic alcohols such as methanol, ethanol, and isopropanol.

[0609] The amounts of residual solvent and residual alcohol mentioned above can be determined by gas chromatography.

[0610] Regardless of the method chosen, it is preferable to prepare the composition while minimizing oxygen and water.

[0611] For example, the concentration of dissolved oxygen in the polymerization solution during solution polymerization is preferably less than 300 ppm in the polymerization process. Furthermore, in manufacturing methods using extruders or the like, the oxygen concentration within the extruder is preferably less than 1% by volume, and more preferably less than 0.8% by volume. The water content of the methacrylic resin is preferably adjusted to 1000 ppm by mass or less, and more preferably to 500 ppm by mass or less.

[0612] If within these ranges, it becomes easier and more advantageous to prepare compositions that meet the requirements of the present invention.

[0613] <Characteristics of the Resin Composition>

[0614] -Glass transition temperature-

[0615] The glass transition temperature (Tg) of the resin composition is preferably 105°C to 160°C. More preferably, it is 110°C to 155°C, even more preferably 115°C to 150°C, and most preferably 120°C to 150°C.

[0616] It should be noted that the glass transition temperature can be determined according to JIS-K7121 using the midpoint method. The glass transition temperature of the above-mentioned resin composition is 105°C or higher, ensuring heat resistance even in high-temperature environments such as those from head-mounted displays and electronic devices, as well as in some outdoor and automotive environments. Furthermore, it maintains its shape even at high temperatures, making it preferable from the viewpoint of improving adhesion when bonded to various optical films.

[0617] On the other hand, when the glass transition temperature (Tg) is below 160°C, melting processing under extreme high-temperature conditions is avoided, thermal decomposition of resins and other materials is suppressed, and a good product can be obtained. From the viewpoint of further obtaining the above-mentioned effects, the glass transition temperature (Tg) is preferably below 155°C, more preferably below 150°C, and even more preferably below 140°C.

[0618] Furthermore, when the glass transition temperature is greater than 150°C, the mold temperature needs to be kept high in the injection molding process described later to reduce the birefringence of the resin light guide component. When removing the light guide component, the cooling time needs to be extended to suppress deformation such as shrinkage marks, which increases the cycle time. In addition, due to the temperature difference with room temperature, rapid cooling makes it easy for residual deformation to remain in the light guide component. From the viewpoint of fully reducing the birefringence of the light guide component, this is not preferred.

[0619] -Photoelastic coefficient CR-

[0620] For the resin composition, the absolute value of the photoelastic coefficient CR, |CR|, is preferably 10.0 × 10⁻⁶. -12 Pa -1 Hereinafter, 5.0 × 10 is preferred. -12 Pa -1 Hereinafter, 3.0 × 10 is further preferred. -12 Pa -1 Hereinafter, 1.0 × 10 is further preferred. -12 Pa -1The photoelastic coefficient, as documented in various literatures (e.g., see *General Chemistry* (No. 39, 1998, published by the Society's Publication Center)), is defined by the following equations (ia) and (ib). It can be seen that the closer the photoelastic coefficient CR is to zero, the smaller the change in birefringence caused by external forces.

[0621] |CR|=|Δn| / σR (ia)

[0622] |Δn|=|nx-ny| (ib)

[0623] (In the formula, CR represents the photoelastic coefficient, σR represents the tensile stress, |Δn| represents the absolute value of birefringence, nx represents the refractive index in the tensile direction, and ny represents the refractive index in the direction perpendicular to the tensile direction in the plane.)

[0624] If the absolute value of the photoelastic coefficient CR of the above resin composition, |CR|, is 3.0 × 10⁻⁶. -12 Pa -1 The following light guide components, which produce photoelastic birefringence due to stress and dimensional temperature changes when fixing or bonding the lens to the lens barrel or fixture, are sufficiently small to obtain a clear image.

[0625] -Molecular weight and molecular weight distribution-

[0626] The weight-average molecular weight (Mw) of the resin composition, as determined by gel permeation chromatography (GPC) based on polymethyl methacrylate, is preferably in the range of 80,000 to 170,000, more preferably in the range of 90,000 to 170,000, even more preferably in the range of 100,000 to 150,000, and still more preferably in the range of 110,000 to 150,000. If the weight-average molecular weight (Mw) is within the above range, the balance between mechanical strength and flowability is also excellent.

[0627] It should be noted that the weight-average molecular weight (Mw), number-average molecular weight (Mn), and Z-average molecular weight (Mz) of the above-mentioned resin composition can be determined using the following apparatus and conditions.

[0628] Determination apparatus: Gel permeation chromatography (HLC-8320GPC) manufactured by Tosoh Corporation.

[0629] The measurement conditions are as follows.

[0630] Chromatographic columns: Connect one TSKguardcolumn SuperH-H, two TSKgel SuperHM-M, and one TSKgel SuperH2500 in series for use.

[0631] Column temperature: 40℃.

[0632] Developing solvent: tetrahydrofuran, flow rate: 0.6 mL / min, 2,6-di-tert-butyl-4-methylphenol (BHT) was added at 0.1 g / L as an internal standard.

[0633] Detector: RI (Differential Refraction) detector.

[0634] Detection sensitivity: 3.0 mV / min.

[0635] Sample: 0.02 g of light guide component in 20 mL of tetrahydrofuran solution.

[0636] Injection volume: 10 μL.

[0637] Standard samples for the standard curve: Use the following 10 polymethyl methacrylates (PMMA Calibration Kit MM-10) with known and different monodisperse weight peak molecular weights (made by Polymer Laboratories).

[0638]

[0639] Under the above conditions, the RI detection intensity relative to the dissolution time of the light guide component was measured.

[0640] Based on the standard curves obtained by measuring the standard samples mentioned above, the weight-average molecular weight (Mw), number-average molecular weight (Mn), and Z-average molecular weight (Mz) of the light guide component are calculated. Using these values, the molecular weight distributions (Mw / Mn) and (Mz / Mw) are determined.

[0641] -Saturated water absorption rate-

[0642] The saturated water absorption rate of the resin composition can be determined by the measurement method described in the examples described later.

[0643] The saturated water absorption rate is preferably in the range of 0.005% to 3%, more preferably in the range of 0.007% to 2.5%, and even more preferably in the range of 0.01% to 2.0%. By using a resin composition within this range to construct the substrate portion of the light guide component, in addition to maintaining good adhesion to the anti-reflective coating and the reflective coating, high surface accuracy can also be maintained after high temperature and high humidity tests.

[0644] -Melt viscosity-

[0645] For the resin composition, to improve the transferability of the lens shape, a low viscosity and high flowability are preferred, equivalent to the state at injection molding. Therefore, a melt viscosity of [value missing] at 270°C and 1000 sec is desirable. -1Under ideal conditions, the viscosity is preferably 20–235 Pa·sec, more preferably 20–230 Pa·sec, even more preferably 30–180 Pa·sec, and particularly preferably 50–150 Pa·sec. If the melt viscosity is less than 20 Pa·sec, it becomes difficult to control the resin flow during injection, making it difficult to maintain pressure smoothly. This leads to problems such as a deterioration in the surface accuracy of the lens (deviation from the design value or the radius of curvature used as a reference) and surface accuracy degradation caused by shrinkage marks after molding. On the other hand, if the melt viscosity is greater than 235 Pa·sec, the transferability of the lens shape deteriorates due to the decreased resin fluidity. In particular, molding thin-walled lenses becomes significantly difficult. If the resin is forcibly pressed into the mold, the light guide component adheres to the mold, and problems arise such as gaps, cracks, and discoloration and foreign matter caused by resin burn-off during demolding due to failure.

[0646] It should be noted that the melt viscosity is a value measured according to JIS-K7199.

[0647] [Manufacturing method of light guide component]

[0648] The light guide component of this embodiment is formed by molding the above-described resin composition and bonding various components together. From a production point of view, injection molding or injection compression molding is preferred as the manufacturing method of the light guide component of this embodiment.

[0649] Typically, injection molding consists of the following steps: (1) an injection step in which resin is melted and filled into a cavity of a mold with controlled temperature; (2) a pressure holding step in which pressure is applied into the cavity until the gate is sealed and a pressure holding step in which an amount of resin equivalent to the amount of molten resin filled in the injection step is injected into the mold and cooled and shrunk; (3) a cooling step in which the molded article is held until the resin is cooled after the pressure holding is released; and (4) a step in which the mold is opened and the cooled molded article is removed.

[0650] In this embodiment, the temperature setting from the nozzle tip to the center of the injection molding machine barrel is based on the glass transition temperature (Tg) of the methacrylic resin composition used, and is set to Tg+120 to Tg+180°C, preferably Tg+100°C to Tg+160°C, and more preferably Tg+110°C to Tg+150°C.

[0651] Here, molding temperature refers to the control temperature of the belt heater wound around the injection nozzle. By setting it to the above temperature range, the molten resin flows fully, allowing molding to proceed while suppressing degradation caused by resin thermal decomposition. Higher molding temperatures result in higher resin fluidity and make it more difficult to produce oriented birefringence. However, under high-temperature conditions, in addition to the adverse effects of resin thermal decomposition on color tone, transmittance, and haze, gas is generated during injection molding. This generated gas fills the mold, and the gas forced into the grooves during resin filling cannot escape, inhibiting resin filling and thus reducing mold transfer efficiency. The molding temperature should be appropriately selected while observing the condition of the light guide components.

[0652] By raising the mold temperature to near the glass transition temperature (Tg), the birefringence of the light guide component can be reduced. Furthermore, it is preferable to set the actual surface temperature to the desired temperature, rather than the set mold temperature. Specifically, the mold temperature for injection molding the light guide of this embodiment is preferably set to the range of (Tg-30)°C to (Tg+10)°C, relative to the glass transition temperature (Tg) of the resin composition used. More preferably, it is set to (Tg-25)°C to (Tg+5)°C, and even more preferably, it is set to (Tg-20)°C to (Tg)°C. By setting the mold temperature within the above range, the birefringence of the resin composition can be reduced, and furthermore, a light guide component with suppressed warping and good surface accuracy can be obtained. If the mold temperature is less than (Tg-30)°C, the orientation degree increases, and there is a tendency for increased birefringence. In addition, the fluidity of the resin within the mold decreases, therefore, the light guide component develops thickness inhomogeneity, and there is a tendency for surface accuracy to deteriorate. On the other hand, if the temperature is above (Tg+10)℃, the surface accuracy will deteriorate due to the effects of heat on the adhesion of the mold and the shrinkage or warping caused by heat. Therefore, the mold temperature is preferably within the above range.

[0653] The cooling time during injection molding can be set appropriately, but it is preferable to be as long as possible. By cooling slowly, the deformation generated during molding is mitigated by the annealing effect, which tends to reduce birefringence.

[0654] In the manufacturing of the light guide component of this embodiment, residual stress generated by injection molding is mitigated, and an annealing process can be performed to reduce birefringence of the light guide. The annealing temperature is based on the glass transition temperature (Tg) of the resin composition, preferably in the range of (Tg-50)℃ to (Tg)℃, more preferably in the range of (Tg-40)℃ to (Tg-5)℃, and even more preferably in the range of (Tg-30)℃ to (Tg-10)℃. If the annealing temperature is within the above range, residual stress can be eliminated from the light guide without deformation. Alternatively, after a single annealing at a high temperature, the resin composition can be gradually cooled to a low temperature of approximately Tg-50℃ and then subjected to additional annealing. If the resin composition is rapidly cooled from a high temperature, internal deformation may occur, leading to increased birefringence. Furthermore, for annealing within the temperature range of approximately Tg-50℃, a photoelastic modulus of 3 × 10⁻⁶ is preferred. -12 Pa -1 The above-mentioned resin compositions, which contain a large amount of plasticizer at least 0.5 parts by weight relative to 100 parts by weight of resin, are particularly effective. The plasticizer works within the same temperature range, thereby promoting the moderation of internal deformation of the resin and having the effect of reducing birefringence.

[0655] Furthermore, for resin compositions containing a large amount of plasticizer (0.5 parts by mass or more relative to 100 parts by mass of the resin), annealing at approximately (Tg-50) °C to (Tg-20) °C near the melting point of the plasticizer is also effective. In this case, as described above, the plasticizer acts within the same temperature range to promote the mitigation of internal deformation of the resin, suppressing changes in surface shape under high-temperature conditions, and reducing birefringence caused by annealing.

[0656] Furthermore, the injection speed can be appropriately selected based on the desired thickness and size of the light guide component; for example, it can be appropriately selected from a range of 2 to 1000 mm / s. When the thickness of the thinnest part is about 1 mm, it is preferable to set the injection speed high in order to finish the injection before the skin layer is formed. When the thickness of the thinnest part is 4 mm or more, it is preferable to set the injection speed to 1 to 20 mm / s. In addition, in order to suppress the abrupt change in the flow rate of the resin composition into the mold at thin-walled sections such as the gate, it is preferable to appropriately change the injection speed when passing through the gate and after passing through the gate.

[0657] Furthermore, the pressure used for holding pressure can be appropriately selected according to the shape of the light guide component to be obtained, for example, within the range of 30 to 120 MPa. Here, the pressure used for holding pressure refers to the pressure maintained by the screw used to further deliver molten resin from the gate after the molten resin has been filled.

[0658] When light guide components are formed by injection molding, even when the molded body is cooled to around room temperature, the temperature of each surface contact is uneven. Due to these temperature differences, the surface shape of the molded body changes, leading to anisotropic changes. Especially when the surface shape is complex, the residual stress from molding eases over time, and consequently, the dimensions change with strong anisotropy. Therefore, it is difficult to obtain a light guide component that can deformably waveguide an image.

[0659] Therefore, it is preferable that after injection molding, after removing the light guide component from the mold, the surfaces related to the optical design are kept for a specified time, such as one day, to avoid contact with metal or other thermally conductive objects. Specifically, without cutting off the gate, keeping the runner and sprue intact, the sprue is inserted into and held in a test tube rack, and the sprue section is fixed to a tray with tape, etc., and kept in the air with the optically effective surfaces exposed for one day. This makes the temperature distribution of each surface uniform, and even after several days, it is difficult for the surface shape to change, resulting in a molded product with good surface accuracy.

[0660] [Head-mounted display]

[0661] The head-mounted display of this embodiment is characterized by having a light guide component as described in this embodiment.

[0662] The light guide component of this embodiment can suppress defects such as uneven brightness, uneven color, and rainbow patterns, and provide images. Therefore, a head-mounted display equipped with this light guide component can suppress defects such as uneven brightness, uneven color, and rainbow patterns, and provide images.

[0663] In this embodiment of the head-mounted display, in at least one of the light output section and the eye-side waveguide section, the reflectivity of S-polarized light at an incident angle of 30° is greater than the reflectivity of P-polarized light, and the difference between the reflectivity of S-polarized light and the reflectivity of P-polarized light is preferably 5% or more. More preferably, the difference between the reflectivity of S-polarized light and the reflectivity of P-polarized light at an incident angle of 30° is 10% or more, and even more preferably 15% or more.

[0664] In the head-mounted display of this embodiment, it is preferable that partial reflectors are formed on a portion or all of the two sides of the waveguide portion on both sides of the light guide member, transmitting a portion of the light and reflecting the remaining portion of the light. Alternatively, these partial reflectors may be formed on a portion or all of one side of the two waveguide portions, or they may be formed on all of the two waveguide portions.

[0665] In the head-mounted display of this embodiment, it is preferable to waveguide the light with an incident angle larger than that of the substrate portion. While ensuring sufficient light utilization efficiency, it is preferable to waveguide the light with an incident angle smaller than that of the critical angle of the substrate portion of the light guide component.

[0666] In the head-mounted display of this embodiment, such as Figure 6 As shown, the observer's eyeball is preferably connected to the output coupler of the light guide component, and a linear polarizer is provided on the straight line extending outward. If a head-mounted display has this structure, it functions as polarized sunglasses.

[0667] Furthermore, in the head-mounted display with the structure described above, in addition to having a linear polarizer, the head-mounted display may also have a half-wavelength element or a retardation layer that imparts a half-wavelength phase difference. Preferably, as... Figure 7 As shown, the head-mounted display connects the observer's eyeball to the output coupler of the light guide component. A linear polarizer and a half-wave plate are sequentially arranged from the outside side along a straight line extending outwards, or a linear polarizer and a phase difference layer imparting a half-wavelength phase difference are sequentially arranged from the outside side. By adjusting the reflectivity characteristics of some mirrors, mirrors with high reflectivity for S-polarized light are used in the output coupler and the outside waveguide. An image display element emitting S-polarized light (towards the waveguide) displays high transmittance for light incident from the outside. Furthermore, a structure can be designed to display high reflectivity for image light waveguided within the light guide component.

[0668] The head-mounted display of this embodiment can be manufactured using the light guide component of this embodiment through known methods.

[0669] Example

[0670] The present invention is described below with specific embodiments and comparative examples, but is not limited thereto.

[0671] (Evaluation of resin composition and light guide component)

[0672] The following describes a method for measuring the properties of light guide components made of resin compositions and resin compositions.

[0673] <Determination of Flexural Strength and Flexural Modulus>

[0674] By drying the resin composition particles produced in the synthesis example described below at 80–100°C for 24 hours, and then injection molding the methacrylic resin composition using an injection molding machine (Toshiba Machine Co., Ltd., EX-100SX) according to JIS-K6717, a type A dumbbell-shaped test piece with a thickness of 4.0 mm was produced, conforming to ISO 3167. Alternatively, a type A dumbbell-shaped test piece with a thickness of 4.0 mm was produced by injection molding a cyclic olefin copolymer resin composition using an injection molding machine (Japan Steel Works Co., Ltd., J100ADS-110U) according to JIS-K7152-1.

[0675] The central portion of the test piece was cut out to prepare a shaped piece with a length of 80 mm, a width of 10 mm, and a thickness of 4.0 mm. A bending test was conducted according to ISO 178 using a low-load universal testing machine (manufactured by Instrand) at a testing temperature of 23°C, a testing speed of 2 mm / min, and a support distance of 64 mm. Six measurements were performed, and the average value was used to calculate the bending strength (MPa).

[0676] <Analysis of Structural Units>

[0677] In the light guide components manufactured in the embodiments and comparative examples described later, for each structural unit after the substrate portion is shredded, unless otherwise stated, by... 1 H-NMR measurements and 13 C-NMR determination is used to identify each structural unit in the resin composition and calculate its quantity. 1 H-NMR measurements and 13 The measurement conditions for C-NMR are as follows.

[0678] Measurement equipment: JNM-ECZ400S manufactured by Nippon Electronics Co., Ltd.

[0679] Determination solvent: CDCl3 or d6-DMSO.

[0680] Measurement temperature: 40℃.

[0681] It should be noted that when the main chain of the methacrylic resin contains a lactone ring structure, this was confirmed by the methods described in Japanese Patent Application Publication No. 2001-151814 and Japanese Patent Application Publication No. 2007-297620.

[0682] <Specificity of the ring structure ratio of cyclic olefin copolymers>

[0683] In the light guide components manufactured in the embodiments and comparative examples described later, for each structural unit after the substrate portion is shredded, by... 13 C-NMR determination is used to identify each structural unit in the resin composition and calculate its quantity.

[0684] First, 5.0 g of the cyclic olefin resin composition was dissolved in 50 mL of cyclohexane, followed by the addition of 300 mL of methanol for reprecipitation. The mixture was then filtered to separate the methanol-insoluble components. The solvent was allowed to evaporate, and the solid components were collected. The solid components were quantified at a concentration of 5.0 wt / vol%. 1.0 mL of o-dichlorobenzene-d4 was added, and the mixture was allowed to stand at room temperature for at least 16 hours to ensure complete dissolution. 13 C-NMR determination.

[0685] For quantification, the ratio of CH to CH2 is calculated as the sum of the integral values ​​k of all peaks observed in the range of 51.2 ppm to 36.8 ppm and the sum of the integral values ​​l of all peaks observed in the range of 36.8 ppm to 29.3 ppm, respectively. Using the following formula (i), the ratio of a specified amount of olefin to cyclotetracyclo[4.4.0.12, 5.17, 10]-3-dodecene in a molar ratio of n% to ((100-n)%) of cyclotetracyclo[4.4.0.1]. 2，5 1. 7，10 ]-3-dodecene copolymer.

[0686] n (%) = (4×l-2×k) / (4×lk)×100 (i)

[0687] It should be noted that, 13 The C-NMR measurement conditions are as follows.

[0688] Measurement equipment: AVANCE 3500HD Prodigy, manufactured by Bruker Biospin company.

[0689] Solvent used for determination: o-dichlorobenzene-d4.

[0690] Measurement temperature: 25℃.

[0691] Observation frequency: 125MHz.

[0692] Pulse sequence: 13 C quantification.

[0693] Number of integration operations: 700.

[0694] Cool-down time: 10 seconds.

[0695] Sample concentration: 5.0 wt / vol.

[0696] <Determination of Plasticizer Content in Resin Compositions>

[0697] The dosage added to the light guide components manufactured in the embodiments and comparative examples described later was analyzed through the following operations.

[0698] First, the substrate portion of the light guide component was cut out. 5.0 g of the resin composition constituting the substrate was added to 100 mL of chloroform (or 50 mL of cyclohexane in the case of a cyclic olefin copolymer). The mixture was stirred at 40°C for at least 1 hour to dissolve the resin. The solution was then placed in a dropping funnel and added dropwise to 1 L of methanol stirred with a stir bar for approximately 0.5–1 hour to allow for reprecipitation. After all the methanol had been added, the mixture was allowed to stand for 1 hour. Then, it was filtered using a membrane filter (Advantec Toyo Co., Ltd., T05A090C).

[0699] For the filtrate, a rotary evaporator was used with a bath temperature of 40°C and a vacuum gradually reduced from the initial setting of 390 Torr to 30 Torr to remove the solvent. The remaining soluble components in the flask were then recovered as the methanol-soluble components. The solid components were measured at a sample concentration of 5.0 wt / vol%, and 1.0 mL of CDCl3 was added. The mixture was allowed to stand at room temperature for at least 30 minutes to allow the sample to completely dissolve. Then, 1000 ppm of DMSO (dimethyl sulfoxide) (mg by weight) was added as an internal standard. 1 H-NMR determination.

[0700] For volume determination, the integral value (a) corresponding only to the 6H of DMSO is subtracted from the integral value (b) of the components observed at 2.79–2.88 ppm, such as pentaerythritol tetra[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate]: BASF "Irganox 1010", tris(2,4-di-tert-butylphenyl) phosphite: BASF "Irgafos 168" and other heat stabilizers and release agents. The result is used as the integral value (ab) for DMSO only. Furthermore, the percentage content (x) of each compound is quantified using the integral value (y) of the peak observed within the following chemical shift range, the molecular weight (M) of the additive, the number of peaks with equivalent protons (z), and the following formula (ii).

[0701] x (%) = (w / 78.1×y / (ab)×6 / z×M) / 5000×100 (ii)

[0702] In particular, for additives containing higher fatty acid esters, quantification is performed using the integrated value y of the peak from the α-hydrogen at the higher fatty acid site observed at 2.0–2.5 ppm, the molecular weight M, the equivalent number of hydrogens from the α-hydrogen z, and formula (II). The integration range and M, z are shown below for the additives corresponding to the examples.

[0703] Pentaerythritol distearate

[0704] Integration range: 2.27ppm~2.38ppm; M=669.09; z=4.

[0705] Pentaerythritol tetrastearate

[0706] Integration range: 2.27ppm~2.38ppm; M=1201.99; z=8.

[0707] It should be noted that, 1 The determination conditions for H-NMR are as follows.

[0708] Measurement equipment: AVANCE 3500HD Prodigy, manufactured by Bruker Biospin company.

[0709] Solvent used for determination: CDCl3.

[0710] Measurement temperature: 25℃.

[0711] Observation frequency: 500MHz.

[0712] Number of integration operations: 128.

[0713] Sample concentration: 5.0 wt / vol.

[0714] <Molecular weight and molecular weight distribution (1)>

[0715] In the light guide components manufactured in the examples and comparative examples described later, the weight-average molecular weight (Mw), number-average molecular weight (Mn), and Z-average molecular weight (Mz) after the portion of the light guide component was cut out were measured under the apparatus and conditions described below. It should be noted that the ring structure contained in the main chain is composed of cyclic olefins. When the light guide component is manufactured using a resin composition containing a copolymer of ethylene or α-olefin and a cyclic olefin, i.e., a cyclic olefin copolymer, the measurements were taken under the conditions described in <Molecular Weight and Molecular Weight Distribution (2)> described later.

[0716] Determination apparatus: Gel permeation chromatography (HLC-8320GPC) manufactured by Tosoh Corporation.

[0717] The measurement conditions are as follows.

[0718] Chromatographic columns: Connect one TSKguardcolumn SuperH-H, two TSKgel SuperHM-M, and one TSKgel SuperH2500 in series for use.

[0719] Column temperature: 40℃.

[0720] Developing solvent: tetrahydrofuran, flow rate: 0.6 mL / min, 2,6-di-tert-butyl-4-methylphenol (BHT) was added at 0.1 g / L as an internal standard.

[0721] Detector: RI (Differential Refraction) detector.

[0722] Detection sensitivity: 3.0 mV / min.

[0723] Sample: 20 mL of tetrahydrofuran solution containing 0.02 g of a methacrylic resin composition.

[0724] Injection volume: 10 μL.

[0725] Standard samples for the standard curve: Use the following 10 polymethyl methacrylates (PMMA Calibration Kit MM-10) with known and different monodisperse weight peak molecular weights (made by Polymer Laboratories).

[0726]

[0727] Under the above conditions, the RI detection intensity relative to the dissolution time of the methacrylic resin composition was determined.

[0728] Based on the standard curves obtained by measuring the standard samples mentioned above, the weight-average molecular weight (Mw), number-average molecular weight (Mn), and Z-average molecular weight (Mz) of the methacrylic resin composition were determined, and the molecular weight distribution (Mw / Mn) and (Mz / Mw) were determined using these values.

[0729] <Molecular weight and molecular weight distribution (2)>

[0730] In the light guide components manufactured in the examples and comparative examples described later, the resin composition used contains a ring structure in the main chain composed of cyclic olefins. In the case of a resin composition containing a copolymer of ethylene or α-olefin and a cyclic olefin, i.e., a cyclic olefin copolymer, the weight-average molecular weight (Mw), number-average molecular weight (Mn), and Z-average molecular weight (Mz) after cutting out a portion of the light guide component were measured under the apparatus and conditions described below.

[0731] Measurement device: Agilent Technologies (PL-GPC220).

[0732] The measurement conditions are as follows.

[0733] Chromatographic column: Two TSKguardcolumn GMHHR-H(20)HT (7.8 mm I.D. × 30 cm) are connected in series for use.

[0734] Column temperature: 145℃.

[0735] Developing solvent: o-dichlorobenzene. Contains 0.05% 2,6-di-tert-butyl-4-methylphenol (BHT).

[0736] Detector: RI (Differential Refraction) detector.

[0737] Detection sensitivity: 3.0 mV / min.

[0738] Sample: Weigh the sample to a concentration of 1 mg / mL and place it in a high-temperature filter. Add 5 mL of eluent and heat at 145 °C for 30 minutes. Shake for 1 hour to dissolve the sample.

[0739] Injection volume: 500μL.

[0740] Flow rate: 0.7 mL / min.

[0741] Standard curve using standard samples: The following 10 polystyrene samples with known and different monodisperse weight peak molecular weights were used.

[0742]

[0743] Under the above conditions, the RI detection intensity relative to the dissolution time of the resin lens was measured.

[0744] Based on the standard curves obtained by measuring the standard samples mentioned above, the weight-average molecular weight (Mw), number-average molecular weight (Mn), and Z-average molecular weight (Mz) of the resin were determined. Using these values, the molecular weight distribution (Mw / Mn) and (Mz / Mw) were determined.

[0745] <Determination of Glass Transition Temperature>

[0746] The glass transition temperature (Tg) (°C) was determined according to JIS-K7121.

[0747] First, in the light guide components manufactured in the examples and comparative examples described later, after being conditioned under standard conditions (23°C, 50%RH) (placed at 23°C for 1 week), as test pieces, four points (four locations) were cut from the portion cut out of the light guide component, each containing approximately 10mg.

[0748] Then, using a differential scanning calorimeter (Perkin Elmer Japan, Diamond DSC) at a nitrogen flow rate of 25 mL / min, the sample was heated from room temperature (23°C) to 200°C at a rate of 10°C / min (single heating), held at 200°C for 5 minutes to allow complete melting, and then cooled from 200°C to 40°C at a rate of 10°C / min, held at 40°C for 5 minutes. Further, the sample was heated again under the same conditions (second heating). During this period, the intersection point (glass transition temperature of the methacrylic resin composition) of the step-like change curve during the second heating and the straight line equidistant from the extensions of each baseline in the longitudinal direction was determined according to JIS-K7121.

[0749] A differential scanning calorimeter (PerkinElmer, Japan, DSC 8000) was used under nitrogen flow rate of 25 mL / min. The sample was heated from room temperature (23°C) to 200°C at a rate of 10°C / min (single heating), held at 200°C for 5 minutes to allow complete melting, then cooled from 200°C to 40°C at a rate of 10°C / min, held at 40°C for 5 minutes, and then heated again under the same conditions (second heating). The glass transition temperature (Tg) (°C) was determined by intersecting the step-like change portion of the differential scanning calorimeter (DSC) curve during the second heating with the straight line equidistant from the extensions of the baselines along the vertical axis. Four measurements were taken for each sample, and the arithmetic mean of the four measurements (rounded to the nearest decimal) was used as the final value.

[0750] <Determination of the absolute value of the photoelastic coefficient (CR)>

[0751] A vacuum compression molding machine was used to form a mold of the portion after the substrate portion of the light guide component manufactured in the embodiments and comparative examples described later, which was then used as a test sample.

[0752] As for specific sample preparation conditions, a vacuum compression molding machine (SFV-30 type, manufactured by Shinto Metal Industries, Ltd.) was used. After preheating for 10 minutes at 260°C and reduced pressure (approximately 10 kPa), the portion cut from the light guide component was compressed for 5 minutes at 260°C and approximately 10 MPa. After depressurization and release of pressure, the sample was transferred to a cooling compression molding machine for cooling and solidification. The resulting mold was cured in a constant temperature and humidity chamber at 23°C and 60% humidity for more than 24 hours, and then test pieces (approximately 150 μm thick and 6 mm wide) were cut out for measurement.

[0753] The photoelastic coefficient CR (Pa) was measured using a birefringence measuring apparatus detailed in *Polymer Engineering and Science* (1999, 39, 2349-2357). -1 ).

[0754] The membrane-like test piece was placed in a membrane stretching apparatus (manufactured by Imoto Manufacturing Co., Ltd.) also set up in a constant temperature and humidity chamber, with the distance between the clamps being 50 mm. Then, the apparatus was configured such that the laser path of the birefringence measuring device (manufactured by Otsuka Electronics, RETS-100) was located at the center of the membrane, and tensile stress was applied at a strain rate of 50% / min (clamp distance: 50 mm, clamp movement speed: 5 mm / min), while the birefringence of the test piece was measured.

[0755] Based on the relationship between birefringence (Δn) and tensile stress (σR) obtained through measurement, the slope of the straight line is approximated using the least squares method, and the photoelastic coefficient (CR) (Pa) is calculated. -1 The calculations used data where the tensile stress was between 2.5 MPa ≤ σR ≤ 10 MPa.

[0756] CR=Δn / σR

[0757] Here, birefringence (Δn) is the value shown below.

[0758] Δn=nx-ny

[0759] (nx: refractive index in the stretching direction, ny: refractive index in the plane perpendicular to the stretching direction.)

[0760] <Phase difference within the effective area of ​​the light guide component>

[0761] For the light guide components obtained through the examples and comparative examples, with one of the two surfaces constituting the waveguide as the lower surface, the surface distribution of the phase difference in the effective region was measured using a PA-300-L birefringence evaluation system manufactured by Photonic Lattice Inc. at a wavelength of 520 nm. The region was specified within the effective region, and the average value (nm) of the absolute value of the phase difference was calculated.

[0762] <Measurement of PV value for surface accuracy of light guide components>

[0763] The surface accuracy was measured using the NH-3SPs (manufactured by Mitaka Koki Co., Ltd.), a non-contact 3D measuring machine, with a fixed fixture positioned so that the surface under test faced the objective lens side of the NH-3SPs. A 100x lens was used as the objective lens. When the shape of the light guide component had a protrusion that interfered with the objective lens and made it difficult to measure the shape, the protrusion was removed before measurement, or a rotating stage was used.

[0764] exist Figure 8 In the configuration shown, measurements are taken at a point 1 / 50th of the length offset inward from the outer periphery of the light guide along both the x-axis and z-axis directions. For PV value measurement, measurements are performed on all surfaces related to the waveguide of the image light, and the value of the surface with the highest PV value is taken as the PV value of the light guide.

[0765] During the measurement, the measurement interval m in the x-axis direction was set to 1 / 1000 of the longest part of the light guide in the x-axis direction, and the measurement interval in the z-axis direction was set to 1 / 10 of the longest part of the light guide in the z-axis direction. It should be noted that when the light guide surface has a diffraction-functional area, the PV value is calculated by measuring the surface area after removing that area.

[0766] The smaller the PV value, the higher the flatness of the light guide, the better the appearance after the warp and thickness unevenness are suppressed, and the better the image quality.

[0767] It should be noted that when the area of ​​the light guide is large, for example, the length in the z-axis direction is 50 mm and it is located away from the z-axis direction of the stage, the measurement range is divided into two parts with a length of 25 mm in the z-axis direction to make the measurement range equal, and the average value of each measurement result is taken as the PV value.

[0768] <Polarized reflectivity characteristics of partial reflectors in light guide components>

[0769] Using a device from the Shimadzu UV-2600 spectrophotometer, which includes a large sample chamber, a variable incident angle device, a light guide component setting axis, and a large polarizer assembly, the polarization reflectivity of a partial reflector formed on a light guide component obtained through the examples and comparative examples was measured.

[0770] For the incident light aperture mask, a rectangular aperture mask with an opening of 5mm was used. The angle of incidence relative to the partial reflecting mirror surface was adjusted to be 15 to 60 degrees. The angle-variable integrating sphere was set to the angle at which the reflected light entered, and the reflectivity was measured. To avoid the influence of reflected light from other surfaces of the sample on the measurement, the surfaces other than the measurement surface were sanded with sandpaper, coated with black paint, and then the measurement was performed.

[0771] An example of the measurement results after coating a portion of the reflective mirror with a reflectivity set to 35% is shown below. Figure 9 In various wavelengths of blue (450nm), green (530nm), and red (630nm), it was confirmed that the reflectivity of polarized light varies with the incident angle.

[0772] For the reflectivity at an incident angle of 30 degrees, there is a difference of about 17% between Rs and Rp, and Rs / Rp is 1.8.

[0773] <Polarization retention characteristics (Tp / Tc) of light guide components>

[0774] according to Figure 10A or Figure 10B The components were arranged in the positions shown, and the polarization retention characteristics (Tp / Tc) of the light guide component obtained through the embodiments and comparative examples were measured.

[0775] A Gran-Thompson prism-type polarizing element 72 (a polarizing element that transmits linearly polarized light with specific vibrations and cannot transmit linearly polarized light vibrating along an axis orthogonal to the vibration axis of the linearly polarized light) is configured as a linear polarizer, orthogonal to the axis of the light from the laser source 71 (which, depending on the measured wavelength, uses any one of blue, green, or red laser sources; hereinafter, sometimes abbreviated as blue LD, green LD, or red LD). The light from the laser source 71 is incident from a direction perpendicular to the light incident portion 731 of the light guide member 73, thus directing the laser beam into the member. After waveguided by the outer side waveguide portion 732 and the eye-side waveguide portion 733 of the light guide member, the light extracted by the output coupler 734 is subjected to an extinction ratio of 10 via the linear polarizer 74 (manufactured by SIGMAKOKI CO.,LTD., SPF-50C-32, 500nm conditions). 4 The power meter 75 configured above measured the optical output.

[0776] For incident polarized light, when a linear polarizer 72 is configured to transmit S-polarized light with a vibration axis perpendicular to the incident surface in the waveguide section of the light guide, the light output when the transmission axis of the linear polarizer 74 also transmits the S-polarized light is taken as Tp, and the light output when the linear polarizer 74 is rotated 90 degrees and P-polarized light is transmitted and measured is taken as Tc. The polarization retention characteristic (Tp / Tc) of the S-polarized light is then calculated. The influence of the difference between the reflectivity of the S-polarized light and the reflectivity of the P-polarized light at an incident angle of 30° for some of the mirrors is removed from the evaluation. Therefore, the value obtained by dividing the obtained polarization retention characteristic (Tp / Tc) of the S-polarized light by the ratio of polarized reflectivity (Rs / Rp) is taken as the measured value. When designing the reflectivity of multiple mirrors, the value obtained by dividing the (Tp / Tc) by the largest value of the ratio of polarized reflectivity (Rs / Rp) is taken as the measured value.

[0777] Similarly, for incident polarized light, when a linear polarizer 72 is configured to receive P-polarized light with a vibration axis parallel to the incident plane in the waveguide section of the light guide, the light output when the transmission axis of the linear polarizer 74 also transmits the P-polarized light is taken as Tp, and the light output when the linear polarizer 74 is rotated 90 degrees and S-polarized light is transmitted and measured is taken as Tc. The polarization retention characteristic (Tp / Tc) of the P-polarized light is then calculated. Then, the influence of the difference between the reflectivity of S-polarized light and the reflectivity of P-polarized light at an incident angle of 30° for some of the mirrors is removed for evaluation. Therefore, the value obtained by multiplying the obtained polarization retention characteristic (Tp / Tc) of S-polarized light by the ratio of polarized reflectivity (Rs / Rp) is taken as the measured value. When designing the reflectivity of multiple mirrors, the value obtained by multiplying the largest value of the ratio of polarized reflectivity (Rs / Rp) by the aforementioned (Tp / Tc) is taken as the measured value.

[0778] Measurements were performed using lasers of blue, green, and red wavelengths, respectively.

[0779] <Light extraction efficiency of light guide components>

[0780] The aforementioned polarization retention properties (Tp / Tc) were measured. Figure 10A or Figure 10B The positional relationships shown were used to measure the light utilization efficiency of the light guide components obtained through the embodiments and comparative examples.

[0781] First of all, Figure 10A or Figure 10B In the configuration, a power meter 75 is installed in front of the laser source 71 that outputs green light and the light from the Gran-Thompson prism polarizing element 72, and just before it enters the light guide component, to measure the light output T0.

[0782] Then, similarly to the determination of the aforementioned polarization retention characteristic (Tp / Tc), the method was used... Figure 10A or Figure 10B The components are arranged in a specific positional relationship. The light from the green laser source is incident on the waveguide component, and the light intensity of the laser emitted from the light extraction unit is measured by a power meter 75 via a linear polarizer 74.

[0783] The light extraction efficiency was determined based on the ratio of the light output Tp measured by the light extraction unit to the initial light output T0 incident on the waveguide component. The S-polarized light Tp / T0 under the condition of S-polarized light incident on the reflecting surface of the waveguide component and the P-polarized light Tp / T0 under the condition of P-polarized light incident on the reflecting surface of the waveguide component were measured respectively.

[0784] <Image Evaluation>

[0785] The image was evaluated using the light guide components obtained through the embodiments and comparative examples. For example... Figure 11 As shown, a simulation device embodying the principle of an AR head-mounted display was created in a dark room.

[0786] In this simulation device, a miniature OLED panel 111 (manufactured by Seeya company, SY103WAM13-00) is configured to output an image. The image is displayed as a white screen. Image light is directed from the light incident section 1151 of the light guide member 115 into the light guide member 115 via an aperture mask 112, a collimating optical system 113, and a linear polarizer 114. Then, after waveguide formation in the waveguide section, a camera captures the image light output from the light guide member via the light output section through the output coupler.

[0787] For the captured images, as condition 1, an evaluation was conducted according to the following criteria based on the viewpoints of uneven brightness, uneven color, and iridescence.

[0788] No uneven brightness, uneven color, or rainbow patterns were observed: A.

[0789] Slight unevenness in brightness was observed: B.

[0790] Uneven brightness and color were observed: C.

[0791] Uneven brightness, uneven color, and rainbow patterns were observed: D.

[0792] Then, for the captured image, as condition 2, the presence or absence of image deformation is determined according to the following criteria.

[0793] No image deformation was observed: A.

[0794] Slight image distortion was observed: B.

[0795] Observed image deformation: C.

[0796] Obvious image distortion was observed: D.

[0797] [raw material]

[0798] The following shows the raw materials used in the embodiments and comparative examples described later.

[0799] [Monomers that constitute methacrylic resins]

[0800] Methyl methacrylate (MMA): manufactured by Asahi Kasei Co., Ltd.

[0801] N-Phenylonmaleimide (PMI): Manufactured by Nippon Shokubai Co., Ltd.

[0802] N-cyclohexylmaleimide (CMI): manufactured by Nippon Shokubai Co., Ltd.

[0803] Styrene: Manufactured by Fujifilm and Waku Pure Chemical Industries, Ltd.

[0804] α-Methylstyrene: Manufactured by Fujifilm and Koh Genuine Chemicals Co., Ltd.

[0805] 2-(hydroxymethyl)acrylate (MHMA): Manufactured by Combi-Blocks company.

[0806] [[Organic solvents]]

[0807] Meta-xylene (mXy): manufactured by Mitsubishi Gas Chemical Co., Ltd.

[0808] Methyl isobutyrate: Manufactured by Kanto Chemical Co., Ltd.

[0809] Toluene: Manufactured by Fujifilm and Wako Pure Chemical Industries, Ltd.

[0810] [Polymerization initiator]

[0811] 1,1-Di(tert-butylperoxide)cyclohexane: manufactured by Nippon Oil Co., Ltd.

[0812] tert-amyl peroxide-2-ethylhexanoate: manufactured by ARKEMA Yoshitomi, Ltd., “Luperox 575”.

[0813] Tert-amyl peroxide isonononate: manufactured by ARKEMA Yoshitomi, Ltd.

[0814] [Chain transfer agent]

[0815] Octylthiol: Manufactured by Chevron Phillips Chemical Company.

[0816] n-Dodecyl mercaptan: Manufactured by Fujifilm and Kohden Chemical Industries, Ltd.

[0817] [[additive]]

[0818] Pentaerythritol tetra[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate]: BASF, “Irganox 1010”.

[0819] Tris(2,4-di-tert-butylphenyl) phosphite: manufactured by BASF, “Irgafos168”.

[0820] RIKEMAL H-100: Manufactured by Riken Vitamin Co., Ltd.

[0821] ADK STAB 2112: Made by ADEKA company.

[0822] Stearyl phosphate / distearate phosphate mixture: manufactured by Sakai Chemical Industry Co., Ltd.

[0823] ADK STAB PEP-36: Manufactured by ADEKA company.

[0824] Octadecyl-3-(3,5-di-tert-butyl-4-hydroxyphenyl)-propionate: manufactured by BASF, “Irganox1076”.

[0825] Monomethylamine: Manufactured by Mitsubishi Gas Chemical Co., Ltd.

[0826] Dimethyl carbonate: Manufactured by Fujifilm and Kazuko Pure Chemicals Co., Ltd.

[0827] Triethylamine: Manufactured by Fujifilm and Koh Geny Pharmaceutical Co., Ltd.

[0828] Pentaerythritol distearate: "Unistar H-476D" manufactured by NOF Co., Ltd.

[0829] Pentaerythritol tetrastearate: "Unistar H-476" manufactured by NOF Co., Ltd.

[0830] (Synthesis Example 1 [Methacrylic A-based Resin Composition A])

[0831] Measure 318.7 kg of methyl methacrylate (hereinafter referred to as MMA), 35.5 g of N-phenylmaleimide (hereinafter referred to as PMI), 63.7 kg of N-cyclohexylmaleimide (hereinafter referred to as CMI), 0.341 kg of n-octylthiol as a chain transfer agent, and 225.1 kg of m-xylene (hereinafter referred to as mXy), and add them to a 1.25 m³ container equipped with a jacket-based temperature control device and a stirring blade. 3 The mixture is stirred in the reactor to obtain a mixed monomer solution.

[0832] Then, 116.9 kg of mXy was measured and added to tank 1 to prepare additional solvent.

[0833] Measure 104.5 kg of MMA and 85.5 kg of mXy and place them in tank 2, stir, and obtain the supplementary MMA solution.

[0834] Nitrogen-based bubbling was performed on the internal liquid of the reactor at a rate of 30 L / min for 1 hour, and nitrogen-based bubbling was performed on tank 1 and tank 2 at a rate of 10 L / min for 30 minutes respectively to remove dissolved oxygen.

[0835] Then, steam was blown into the jacket to raise the solution temperature in the reactor to 125°C. While stirring at 50 rpm, a polymerization initiator solution consisting of 0.457 kg of 1,1-di(tert-butylperoxide)cyclohexane dissolved in 2.67 kg of mXy was added at a rate of 1 kg / h to initiate polymerization. It should be noted that during polymerization, the solution temperature in the reactor was controlled at 125 ± 2°C based on the jacket temperature regulation. Thirty minutes after the start of polymerization, the addition rate of the polymerization initiator solution was reduced to 0.25 kg / h, and then mXy was added from tank 1 at a rate of 29.24 kg / h for 3.5 hours.

[0836] Then, 4 hours after the start of polymerization, the addition rate of the polymerization initiator solution was increased to 0.75 kg / h, and supplementary MMA solution for 2 hours was added from tank 2 at 95 kg / h.

[0837] Furthermore, 6 hours after the start of polymerization, the addition rate of the polymerization initiator solution was reduced to 0.25 kg / hour, and the addition was stopped 7 hours after the start of polymerization.

[0838] Eight hours after the start of polymerization, a polymerization solution containing methacrylic resin was obtained. 0.261 kg of Irganox 1010 as an antioxidant, 0.784 kg of Irgafos 168, and 0.784 kg of RIKEMAL H-100 as a release agent were added to the solution.

[0839] The obtained polymerization solution is then fed to a concentration device consisting of a tubular heat exchanger preheated to 250°C and a vaporization tank for devolatilization. The vacuum level of the vaporization tank is set to 10–15 Torr. The resin flowing down from the vaporization tank is discharged by a screw pump, extruded from a drawing die, and water-cooled before granulation to obtain granules of methacrylic resin composition A having N-substituted maleimide structural units.

[0840] The obtained particles had a glass transition temperature (Tg) of 133℃ and a flexural strength of 66 MPa. Other properties are summarized in the table. Additionally, based on... 1 The oxygen weight ratio determined by the monomer composition from the H-NMR composition is 29% by weight.

[0841] (Synthesis Example 2 [Methacrylic Acid Resin Composition B])

[0842] A monomer composition consisting of 75,000 mol% MMA, 24,998 mol% styrene, and 0.002 mol% tert-amyl peroxide-2-ethylhexanoate as a polymerization initiator was continuously fed at a rate of 1 kg / h into a 10 L fully mixed tank equipped with helical ribbon blades, and continuous polymerization was carried out at an average residence time of 2.5 hours and a polymerization temperature of 150 °C. The polymer was continuously extracted from the bottom of the tank with a constant liquid level and fed to a concentration unit consisting of a tubular heat exchanger and a vaporization tank for devolatilization. The vacuum level in the vaporization tank was set to 10–15 Torr. The resin flowing down from the vaporization tank was discharged using a screw pump, extruded from a drawing die, water-cooled, granulated, and introduced into a desolventizing unit to obtain granular methyl methacrylate-styrene copolymer.

[0843] The copolymer was dissolved in methyl isobutyrate to prepare a 10% (w / w) methyl isobutyrate solution. 500 parts by weight of the 10% (w / w) methyl isobutyrate solution of the copolymer and 1 part by weight of 10% (w / w) Pd / C (manufactured by NE CHEMCAT CORPORATION) as a hydrogenation catalyst were added to a 1000 mL autoclave. The mixture was maintained at a hydrogen pressure of 9 MPa and 200°C for 15 hours to hydrogenate the aromatic double bonds in the styrene portion of the copolymer. The hydrogenation catalyst was removed by a filter, and 0.04 parts by weight of RIKEMAL H-100 was added to the polymer solution. After mixing, the mixture was fed to a concentration device consisting of a tubular heat exchanger and a vaporization tank for devolatilization. The vacuum degree of the vaporization tank was set to 10–15 Torr. The resin flowing from the vaporization tank was discharged using a gear pump, extruded from a drawing die, and water-cooled before granulation to obtain methacrylic resin composition B particles.

[0844] The obtained particles have a glass transition temperature (Tg) of 119°C and a flexural strength of 95 MPa. Other properties are summarized in the table. Additionally, the oxygen weight percentage, calculated based on the monomer composition ratio, is 24% by weight. 1 The H-NMR composition was determined.

[0845] (Synthesis Example 3 [Methacrylic Acid Resin Composition C])

[0846] 2.25 kg of methyl methacrylate, 0.32 kg of methyl 2-(hydroxymethyl)acrylate, 0.024 kg of styrene, 0.025 parts by mass of n-dodecyl mercaptan (as a chain transfer agent relative to 100 parts by mass of all monomers finally added to the reactor), 0.025 parts by mass of ADK STAB 2112, and 5.39 kg of toluene were added to the reactor. Nitrogen was introduced into the reactor, and the temperature was raised to 105°C while stirring.

[0847] As an initial initiator, a solution consisting of 0.20 kg of toluene and 0.014 kg of tert-amyl peroxyisononanoate was added dropwise to the polymerization tank over 10 minutes, while polymerization was carried out at 105°C–110°C. Further, after 10 minutes, a solution consisting of 0.26 kg of toluene and 0.017 kg of tert-amyl peroxyisononanoate was added dropwise over 3 hours. Simultaneously with the addition of this initiator solution, a solution consisting of 2.75 kg of methyl methacrylate, 0.40 kg of methyl 2-(hydroxymethyl)acrylate, and 0.24 kg of styrene was added dropwise over 3 hours, while polymerization was carried out at 105–110°C, followed by a 2-hour curing period.

[0848] A mixture of 4.5 g of stearyl phosphate / distearate phosphate and 72 g of toluene was added to the obtained polymer solution, and a cyclization condensation reaction was carried out at 90–110 °C for 1.5 hours. Then, 0.10 parts by mass of RIKEMAL H-100 relative to the total amount of monomers finally added to the reactor were added, and the mixture was stirred.

[0849] Uses a device with four front exhaust outlets and one rear exhaust outlet. A 42mm devolatilization extruder was used to perform cyclization condensation reaction and devolatilization treatment on the obtained polymer liquid at a barrel temperature of 220℃, 120rpm, and a resin rate of 5kg / hour to obtain granules of methacrylic resin composition C.

[0850] The obtained particles have a glass transition temperature (Tg) of 127°C and a flexural strength of 98 MPa. Furthermore, the oxygen weight percentage, calculated based on the monomer composition ratio, is 31% by weight. 1 The H-NMR composition was determined.

[0851] (Synthesis Example 4 [Methacrylic Acid Resin Composition D])

[0852] A co-rotating twin-screw extruder with a screw diameter of 40 mm was used. The extruder barrel temperature was set to 275°C, and the screw speed was set to 150 rpm. Polymethyl methacrylate (PMMA), containing 0.1 parts by weight of RIKEMAL H-100 (based on a total polymer mass of 108,000), was fed from the hopper at a rate of 20 kg / h. Nitrogen was introduced into the extruder at a flow rate of 200 mL / min. The resin was melted by a kneading block, and after filling the hopper, 1.8 parts by weight of monomethylamine relative to 100 parts by weight of the raw resin were injected through the nozzle to initiate an imidization reaction. A reverse thread was placed at the end of the reaction zone (before the vent) to fill it with resin. The pressure at the vent was reduced to 50 Torr to remove reaction byproducts and excess monomethylamine. The resin exiting the die at the extruder outlet was cooled in a water bath and then granulated using a granulator to obtain the imide resin.

[0853] Then, using a co-rotating twin-screw extruder with a screw diameter of 40 mm, the extruder barrel temperature was set to 255°C, the screw speed to 150 rpm, and the obtained imide resin was fed at 20 kg / hr. The resin was melted by a kneading block, and after filling, a mixture of dimethyl carbonate and triethylamine as esterifying agents was injected through the nozzle to reduce the carboxylic acid groups in the resin. The ratio of dimethyl carbonate to triethylamine was 3.2 parts by weight relative to 100 parts by weight of imide resin. The pressure at the vent was reduced to 50 Torr to remove reaction byproducts and excess dimethyl carbonate. After the resin exiting the die at the extruder outlet as a strand was cooled in a water bath, it was granulated using a granulator to obtain granules of methacrylic acid resin composition D with a glutarimide structure.

[0854] The obtained particles have a glass transition temperature (Tg) of 122°C and a flexural strength of 127 MPa. Furthermore, the oxygen weight percentage, calculated based on the monomer composition ratio, is 31% by weight. This monomer composition ratio is based on... 1 The H-NMR composition was determined.

[0855] (Synthesis Example 5 [Methacrylic Acid Resin Composition E])

[0856] Measure 298.5 kg of MMA, 37.0 kg of PMI, 104.5 kg of CMI, 0.23 kg of n-octylthiol as a chain transfer agent, and 247.0 kg of mXy, and add them to a 1.25 m³ container equipped with a jacket-based temperature control device and stirring blades. 3 The reactor is stirred to obtain a mixed monomer solution.

[0857] Then, measure 123.0 kg of mXy and add it to container 1.

[0858] Measure 110.0 kg of MMA and 80.0 kg of mXy and place them in tank 2, then stir to prepare a supplementary monomer solution.

[0859] Nitrogen-based bubbling was performed on the internal liquid of the reactor at a rate of 30 L / min for 1 hour, and nitrogen-based bubbling was performed on tanks 1 and 2 at a rate of 10 L / min for 30 minutes respectively to remove dissolved oxygen.

[0860] Then, steam is blown into the jacket to raise the temperature of the solution in the reactor to 124°C. While stirring at 50 rpm, a polymerization initiator solution consisting of 0.35 kg of 1,1-di(tert-butylperoxy)cyclohexane dissolved in 4.652 kg of mXy is added at a rate of 1 kg / h to start polymerization. mXy is added from tank 1 at a rate of 30.75 kg / h for 4 hours.

[0861] It should be noted that during polymerization, the solution temperature inside the reactor is controlled at 124±2℃ by jacket-based temperature regulation.

[0862] Then, from 4 hours to 6 hours later, a monomer solution containing MMA is added from tank 2 at a rate of 95 kg / h.

[0863] Furthermore, for the polymerization initiator solution, the addition rate is reduced to 0.25 kg / h after 0.5 hours of polymerization, to 0.75 kg / h after 4 hours, to 0.5 kg / h after 6 hours, and the addition of the polymerization initiator solution is stopped after 7 hours of polymerization. Then, polymerization continues for another 3 hours to obtain a polymerization solution containing methacrylic resin with ring structure units in the main chain.

[0864] 0.83 kg of ADK STAB PEP-36, 0.28 kg of Irgafos168, 0.44 kg of Irganox 1076, and 1.10 kg of RIKEMAL H-100 were added to the polymerization solution under stirring.

[0865] The obtained polymerization solution is then fed to a concentration device consisting of a tubular heat exchanger preheated to 260°C and a vaporization tank for devolatilization. The vacuum level of the vaporization tank is set to 10–15 Torr. The resin flowing from the vaporization tank is discharged by a screw pump, extruded from a drawing die, and water-cooled before granulation to obtain granules of methacrylic resin E having N-substituted maleimide structural units.

[0866] The obtained particles had a glass transition temperature (Tg) of 146℃, a melt viscosity of 210 Pa·sec, and a flexural strength of 59 MPa. Additionally, according to... 1 The oxygen weight ratio determined by the H-NMR composition is 28 by weight.

[0867] (Synthetic Example 6 [Resin Composition F of Cyclic Olefin Copolymer])

[0868] First, vanadium catalysts with a vanadium concentration of 6.7 mmol / L cyclohexane were prepared by diluting VO(OC2H5)Cl2 with cyclohexane. Then, ethyl sesquichloride (Al(C2H5)) was diluted with cyclohexane. 1.5 Cl 1.5 An organoaluminum compound catalyst with an aluminum concentration of 107 mmol / L-hexane was prepared.

[0869] Then, using a stirred polymerizer (500 mm inner diameter, 100 L reaction volume), the reaction of ethylene with tetracyclo[4.4.0.1] was carried out continuously. 2，5 1. 7，10 The copolymerization of 3-dodecene was carried out. Here, ethylene and hydrogen were supplied together into the polymerizer. The hydrogen flow rate was adjusted to achieve the desired molecular weight. During this copolymerization reaction, a vanadium catalyst prepared by the above method was supplied into the polymerizer at a concentration of 0.6 mmol / L relative to cyclohexane used as the polymerization solvent. Additionally, ethyl sesquichloride, an organoaluminum compound, was supplied into the polymerizer at an Al / V ratio of 18.0. The polymerization temperature was set to 8°C, and the polymerization pressure was set to 1.8 kg / cm²G, and the copolymerization reaction was carried out continuously.

[0870] Ethylene extracted from the polymerizer and tetracyclic [4.4.0.1] 2，5 .1 7，10 In a copolymer solution of 3-dodecene, water and a 25% by mass aqueous solution of sodium hydroxide as a pH adjuster were added to stop the polymerization reaction. Additionally, catalyst residue present in the copolymer was removed (de-ashed) from the copolymer solution. After the above de-ashing treatment, the copolymer was reacted with tetracyclo[4.4.0.1]. 2，5 .1 7，10Irganox 1010 as a stabilizer was added to a cyclohexane solution (polymer concentration 7.7% by mass) of the copolymer of 3-dodecene at a rate of 0.4 parts by mass relative to 100 parts by mass of the copolymer. Then, before proceeding to the flash drying process, an effective volume of 1.0 m³ was temporarily used. 3 Mix in the mixing tank for 1 hour.

[0871] Used as a heat source at 20kg / cm² 2 In a double-tube heater (outer tube diameter 2B, inner tube diameter 3 / 4B, length 21m) of steam, a cyclohexane solution of the copolymer with a concentration of 5% by mass in the cyclohexane solution is supplied at a rate of 150 kg / h and heated to 180°C.

[0872] Used as a heat source at 25kg / cm² 2 A double-tube flash dryer (outer tube diameter 2B, inner tube diameter 3 / 4B, length 27m) and a flash hopper (volume 200L) are used to remove cyclohexane, which serves as the polymerization solvent, and most of the unreacted monomers from the cyclohexane solution of the copolymer obtained through the above heating process, thereby obtaining molten ethylene and tetracyclohexane [4.4.0.1] after flash drying. 2，5 .1 7，10 Random copolymers of 3-dodecene (cyclic olefin copolymers).

[0873] The cyclic olefin copolymer was extruded using a twin-screw compounding extruder with a vent, and then granulated using an underwater granulator installed at the extruder outlet. The resulting granules were dried with hot air at 100°C for 4 hours to obtain the cyclic olefin copolymer resin composition F.

[0874] pass 13 C-NMR determination confirmed the compositional ratio of the cyclic olefin copolymer. The results showed that, based on the CH to CH2 ratio, a specified amount of olefin (62 mol%) and a tetracyclic copolymer (38 mol%) were present. [4.4.0.1] 2，5 1. 7 ，10 ]-3-dodecene copolymer. Glass transition temperature (Tg) is 142°C, and flexural strength is 78 MPa. Furthermore, the oxygen weight percentage, calculated based on the monomer composition, is 0% by weight. Other properties are listed in the table.

[0875] (Synthesis Example 7 [Methacrylic Acid Resin Composition G])

[0876] 2.25 kg of methyl methacrylate, 1.25 kg of methyl 2-(hydroxymethyl)acrylate, 0.025 parts by mass of n-dodecyl mercaptan (as a chain transfer agent relative to 100 parts by mass of all monomers), 0.025 parts of ADK STAB2112, and 6.25 kg of toluene were added to a 30 L reactor equipped with a stirring device with paddle-shaped blades, a temperature sensor, a cooling pipe, and a nitrogen inlet pipe. Nitrogen gas was introduced into the reactor, and the temperature was raised to 105 °C while stirring.

[0877] While refluxing, 0.05 parts by mass of tert-amyl peroxyisononanoate relative to 100 parts by mass of all monomers were added to the polymerization tank. Then, 0.1 parts by mass of tert-amyl peroxyisononanoate were added dropwise over 2 hours. Polymerization was carried out under reflux conditions at a polymerization temperature of 105-110°C for another 6 hours.

[0878] 6.3 g of a mixture of stearyl phosphate and distearate phosphate was added to the obtained polymer solution, and a cyclization condensation reaction was carried out at 90–110 °C for 5 hours. Then, 0.15 parts by mass of RIKEMAL H-100 relative to 100 parts by mass of the total monomers were added, and the mixture was stirred.

[0879] Uses a device with four front exhaust outlets and one rear exhaust outlet. The obtained polymer solution was subjected to cyclization condensation reaction and devolatilization treatment using a 42mm devolatilization extruder at 120 rpm, which is equivalent to 2.2 kg / hour of resin, to obtain granules of methacrylic resin composition H.

[0880] The obtained particles have a glass transition temperature (Tg) of 133°C and a flexural strength of 71 MPa. Furthermore, the oxygen weight percentage, calculated based on the monomer composition ratio, is 33% by weight. This monomer composition ratio is based on... 1 The H-NMR composition was determined.

[0881] (Synthetic Example 8 [Methacrylic Acid Resin Composition J])

[0882] 381 kg of MMA, 0 kg of PMI, 37 kg of CMI, 0.38 kg of n-octylthiol (as a chain transfer agent), and 225.1 kg of mXy were measured and added to a 1.25 m³ container equipped with a jacket-based temperature control device and stirring blades. 3 In the reactor, the mixture was stirred to obtain a mixed monomer solution. Furthermore, in the same manner as in Synthesis Example 1, resin composition J particles were obtained.

[0883] The obtained particles have a glass transition temperature (Tg) of 124°C and a flexural strength of 110 MPa. Furthermore, the oxygen weight percentage, calculated based on the monomer composition ratio, is 30.9% by weight.1 The H-NMR composition was determined.

[0884] (Example 1)

[0885] [Forming of light guide components]

[0886] Using the methacrylic resin composition A obtained in Synthesis Example 1, the mixture was injected into an injection molding machine (FANUC company, S-2000i50B, screw diameter...) (26mm) was injection molded. A method for obtaining... Figure 10A The mold for a light guide component of the shape shown (with a waveguide thickness of 2.9 mm, a waveguide distance of 21 mm for the main ray within the light guide component, and a projected length of 18 mm in the waveguide direction). The light incident section, the outer side waveguide section, the eye-side waveguide section (including the light emitting section), and the output coupler are all planar.

[0887] The barrel temperature was set to Tg + 120°C of the resin composition used, and the mold temperature was set to the actual temperature of Tg - 15°C of the resin composition used. The substrate portion of the light guide component was molded. The holding pressure was set to 105 MPa for 5 seconds in the first stage, and then 70 MPa for 3 seconds in the second stage to mitigate internal stress deformation of the molded part. The injection speed was set to an initial speed of 5 mm / s, reduced to 1 mm / s at the gate, and then filled at 4 mm / s beyond the gate, thus performing injection molding to obtain the light guide component of Example 1.

[0888] The surface shape of the obtained molded sheet is measured and placed on a metal tray. The shape of each surface of the light guide component is measured using NH-3SPs (manufactured by Mitaka Optical Co., Ltd.). The molding conditions are adjusted appropriately to obtain the specified shape, and a light guide component of the specified shape is obtained.

[0889] Then, the waveguide component was cleaned using water and a detergent solution containing surfactants via ultrasonic treatment. After vacuum drying at 70°C for 6 hours, an anti-reflective coating was applied to the light incident portion, and partial reflectors with a reflectivity set to 35% in unpolarized light were deposited on the external / eye-side waveguide portion and the output coupler. At a wavelength of 530 nm, the partial reflector had an incident angle of 30 degrees and a reflectivity ratio of Rs / Rp of 1.8, with a reflectivity difference of 17% between Rs and Rp.

[0890] Furthermore, the in-plane phase difference within the effective region of the waveguide (measured within a range where the projected area of ​​the measurement area on the measurement object surface is 90% of the projected area of ​​the entire measurement object surface) is 13 nm. The PV values ​​for each surface are: 2 μm for the incident waveguide, 7.1 μm for the outer waveguide, 12.3 μm for the eye-side waveguide, and 10.4 μm for the output coupler.

[0891] Other evaluation results for the light guide component are shown in Table 1.

[0892] It should be noted that, for the PV values ​​of each surface on the second day after molding, the light incident part is 1.3μm, the external waveguide part is 4.5μm, the eye-side waveguide part is 5.6μm, and the output coupler is 4.6μm. For the PV values ​​of each surface after 5 days, the light incident part is 2.2μm, the external waveguide part is 6.7μm, the eye-side waveguide part is 11.5μm, and the output coupler is 10.5μm.

[0893] (Example 2)

[0894] After injection molding in Example 1, the molded sheet, with the gate not cut off and the runner and sprue remaining, is fixed in the following manner: the sprue is fixed to a plastic tray, such as... Figure 12 The flow channel was fixed with transparent tape in a manner that allowed the light guide component to float in the air, and left to stand for one day in an indoor environment where the temperature was controlled at 23°C. Then, vapor deposition was performed in the same manner as in Example 1, and various measurements were conducted.

[0895] In addition, the PV values ​​for each surface are 0.9 μm for the light incident part, 1.4 μm for the external waveguide part, 3.6 μm for the eye-side waveguide part, and 4.2 μm for the output coupler.

[0896] Other evaluation results for the light guide component are shown in Table 1.

[0897] (Example 3)

[0898] Except for the partial reflector with the reflectivity of the outer side waveguide, eye side waveguide, and output coupler set to 40%, the light guide component was fabricated in the same manner as in Example 2. At a wavelength of 530 nm, the partial reflector has an Rs / Rp ratio of 1.4 at an incident angle of 30 degrees, and the reflectivity difference between Rs and Rp is 13%.

[0899] Other evaluation results for the light guide component are shown in Table 1.

[0900] (Example 4)

[0901] Except for the partial reflector in which the reflectivity of the outer side waveguide, the eye side waveguide, and the output coupler is set to 50%, the light guide component was fabricated in the same manner as in Example 2. At a wavelength of 530 nm, the partial reflector has an incident angle of 30 degrees and an Rs / Rp ratio of 1.3, with a reflectivity difference of 15% between Rs and Rp.

[0902] Other evaluation results for the light guide component are shown in Table 1.

[0903] (Example 5)

[0904] As a light guide component, it is used to obtain Figure 10B A mold for a light guide component (with a waveguide thickness of 5.0 mm, a waveguide distance of approximately 21 mm for the main ray within the light guide component, and a projected length of 30 mm in the waveguide direction) was used. The reflectivity of the outer side waveguide, the eye side waveguide, and the output coupler was 50%. The Rs / Rp of the partial reflector under the 530 nm wavelength condition was 3.0 at an incident angle of 30 degrees, and the reflectivity difference between Rs and Rp was 50%. Furthermore, a partial reflector with a reflectivity difference of 30% between Rs and Rp at an incident angle of 5 degrees was implemented. Otherwise, the light guide component was fabricated in the same manner as in Example 2.

[0905] Other evaluation results for the light guide component are shown in Table 1.

[0906] (Example 6)

[0907] The light guide component obtained after injection molding was annealed at 115°C for 1 hour before being transferred to the process of vapor deposition on each surface. Otherwise, the light guide component was fabricated in the same manner as in Example 2.

[0908] For each surface, the PV value is 2.1 μm for the incident portion, 3.2 μm for the outer side waveguide portion, 8.5 μm for the eye side waveguide portion, and 8.1 μm for the output coupler.

[0909] Other evaluation results for the light guide component are shown in Table 1.

[0910] (Example 7)

[0911] The light guide component obtained after injection molding was annealed at 85°C for 4 hours before being transferred to the process of vapor deposition on each surface. Otherwise, the light guide component was fabricated in the same manner as in Example 2.

[0912] For the PV values ​​of each surface, the light incident part is 1.0 μm, the outer side waveguide part is 2.2 μm, the eye side waveguide part is 5.1 μm, and the output coupler is 4.5 μm.

[0913] Other evaluation results for the light guide component are shown in Table 1.

[0914] (Example 8)

[0915] The methacrylic resin composition A obtained in Synthesis Example 1 was set at 100 parts by weight, and 1.3 parts by weight of a fatty acid ester composed of a tetrahydric alcohol and a fatty acid, namely pentaerythritol tetrastearate (manufactured by Nippon Oil Co., Ltd., "Unistar H-476"), was dry-mixed. Using a twin-screw extruder with vents (screw diameter 30 mm, L / D = 60, manufactured by STEER JAPAN, Omega 30H), the resulting mixed granules were fed into a hopper under nitrogen conditions, and melt-mixed at a barrel temperature of 250°C and a resin pressure of 10 kg / h. After water cooling in a water bath, the mixture was granulated using a granulator to obtain resin composition H.

[0916] The resulting particles had a weight-average molecular weight of 123,000 and a residual amount of pentaerythritol tetrastearate of 0.8% by weight. The light guide component was fabricated under the same conditions as in Example 2, except that the resin composition thus obtained was used.

[0917] Other evaluation results for the light guide component are shown in Table 1.

[0918] (Example 9)

[0919] The light guide component obtained after injection molding was annealed at 85°C for 4 hours before the process of vapor deposition on each surface was transferred. Otherwise, the light guide component was manufactured in the same manner as in Example 8.

[0920] Other evaluation results for the light guide component are shown in Table 1.

[0921] (Examples 10-13)

[0922] Except for using resin compositions B to E obtained in each synthesis example, the light guide component was fabricated under the same conditions as in Example 1.

[0923] The evaluation results for the light guide component are shown in Table 2.

[0924] (Example 14)

[0925] The methacrylic resin composition F obtained in Synthesis Example 6 was set at 100 parts by weight, and 1.2 parts by weight of a fatty acid ester composed of a tetrahydric alcohol and a fatty acid, namely pentaerythritol distearate (manufactured by Nippon Oil Co., Ltd., "Unistar H-476D"), was dry-mixed. Using a twin-screw extruder with vents (screw diameter 30 mm, L / D = 60, manufactured by STEER JAPAN, Omega 30H), the resulting mixed granules were fed into a hopper under nitrogen conditions, and melt-mixed at a barrel temperature of 250°C and a resin pressure of 10 kg / h. After water cooling in a water bath, the mixture was granulated using a granulator to obtain resin composition I.

[0926] The obtained particles had a weight-average molecular weight of 90,000 and a residual amount of pentaerythritol distearate of 0.9% by weight. Other properties are described in Table 2.

[0927] The ratio of 62 mol% to 38 mol% olefins in the obtained cyclic olefin copolymer particles was confirmed to be cyclotetracyclic [4.4.0.1]. 2，5 1. 7，10 [-3-dodecene copolymer. Additionally, the glass transition temperature (Tg) is 137°C, and the flexural strength is 77 MPa. Furthermore, the oxygen weight percentage calculated based on the monomer composition is 0% by weight.]

[0928] Using the resin composition I thus obtained, an injection molding machine (FANUC company, S-2000i50B, screw diameter) was used. (26mm) was injection molded. As the mold, [the following was used] Figure 10A The light guide component has the shape shown. The light incident section, the outer side waveguide section, the eye-side waveguide section (including the light emitting section), and the output coupler are all planar.

[0929] The barrel temperature was set to Tg + 120°C of the resin composition used, and the mold temperature was set to the actual temperature of Tg - 15°C of the resin composition used for molding the light guide component. The holding pressure was set to 125 MPa for 5 seconds in the first stage, and then 90 MPa for 3 seconds in the second stage to mitigate internal stress deformat...

Claims

1. An injection-molded light guide component, used in an image display device having an eyepiece optical system that guides light from an image display element toward an observer's eyeball, characterized in that, The injection-molded light guide component includes: Substrate portion; An input coupler for allowing light from the image display element to enter the light guide body; Two opposing waveguide sections, which waveguide incident light through repeated reflections; and An output coupler that utilizes any one of refraction, diffraction, and reflection to direct light after it has passed through a waveguide toward an observer's eye and extract light from the light guide component. The absolute value of the photoelastic coefficient of the injection-molded light guide component is 10 × 10⁻⁶. -12 Pa -1 the following, On at least one of the three surfaces—the waveguides on both sides and the surface of the output coupler—a partial reflector is formed that transmits a portion of the light and reflects the remaining portion. When the partial reflector is used for reflection at an incident angle of 30°, the difference in reflectivity between the first polarized light (S-polarized) and the second polarized light (P-polarized), which is orthogonal to the first polarized light, is greater than 10% and less than 40%. The in-plane phase difference within the effective region of the waveguide is within 20 nm. The substrate portion is composed of a thermoplastic resin composition having a ring structure in the main chain or side chain, and the glass transition temperature Tg is 115–150°C.

2. The injection-molded light guide component as described in claim 1, characterized in that, The shortest distance between the waveguide sections on both sides is 0.6 mm or more and 25 mm or less. The projected length of the light guide component along the waveguide direction is more than 10 mm and less than 50 mm. The peak-to-valley values ​​within the effective waveguide region of both waveguide sections are below 10.0 μm.

3. The injection-molded light guide component as described in claim 1 or 2, characterized in that, One of the waveguide sections on the two sides is the outer side waveguide section. The outer side waveguide portion has a partially reflecting mirror that transmits a portion of the light and reflects the remaining portion of the light.

4. The injection-molded light guide component as described in claim 1 or 2, characterized in that, In the reflection at the waveguide section, first polarized light with a wavelength of 500-600 nm as S-polarized light is incident. After the light is waveguided by the waveguide section, when the light is extracted from the light extraction section via the output coupler, the value obtained by dividing the ratio Tp / Tc by the ratio Rs / Rp of the surface with the largest S-polarized light reflectivity to P-polarized light reflectivity of the partial reflector is 5 or more. The ratio Tp / Tc is the ratio of the amount of light Tp extracted by the polarizing plate arranged with the first polarization axis aligned with the transmission axis to the amount of light Tc extracted by the polarizing plate arranged with the first polarization axis orthogonal to the transmission axis.

5. The injection-molded light guide component as described in claim 4, characterized in that, The value obtained by dividing the ratio Tp / Tc by the ratio Rs / Rp of the face with the largest ratio Rs / Rp is 10 or greater.

6. The injection-molded light guide component as described in claim 1 or 2, characterized in that, The output coupler is formed with a partial reflector that transmits a portion of the light and reflects the remaining portion of the light.

7. The injection-molded light guide component as described in claim 1 or 2, characterized in that, The thermoplastic resin composition contains 0.5 to 2.8% by weight of higher fatty acid esters.

8. The injection-molded light guide component as described in claim 1 or 2, characterized in that, The thermoplastic resin composition is a methacrylic resin composition.

9. A head-mounted display, characterized in that, The head-mounted display includes the injection-molded light guide component as described in claim 1 or 2.

10. The head-mounted display as claimed in claim 9, characterized in that, In at least one of the light output section and the eye-side waveguide section, the reflectivity of S-polarized light at an incident angle of 5° is greater than that of P-polarized light, and the difference between the reflectivity of S-polarized light and the reflectivity of P-polarized light is more than 5%.

11. The head-mounted display as claimed in claim 9, characterized in that, Partial reflectors are formed on a portion or all of the two surfaces of the waveguide portion on both sides, transmitting a portion of the light and reflecting the remaining portion of the light. The light is waveguided at an incident angle smaller than the critical angle of the substrate portion.

12. The head-mounted display as claimed in claim 9, characterized in that, The observer's eyeball is connected to the output coupler of the light guide component, which has a linear polarizer extending outward in a straight line.

13. The head-mounted display as claimed in claim 9, characterized in that, The observer's eyeball is connected to the output coupler of the light guide component. On a straight line extending outward, a linear polarizer and a half-wave plate are sequentially provided from the outside side, or a linear polarizer and a phase difference layer that imparts a phase difference of 1 / 2 wavelength are sequentially provided from the outside side.

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