Cyclic olefin copolymer resin composition, lens, waveguide and prism

Abstract

To provide a cyclic olefin copolymer resin composition capable of: suppressing birefringence to an extremely small value even at a high-temperature range while suppressing any foreign matter such as white haze in molding or poor appearance; and obtaining an optical component with extremely small birefringence such as a lens even under not so severe mold conditions.SOLUTION: In this invention, provided is a resin composition comprising a cyclic olefin copolymer being a copolymer of ethylene or α-olefin and a cyclic olefin, which has: an absolute value of a photoelastic coefficient measured at 110°C of 10.0×10-12 Pa-1 or less; and a glass-transition temperature of 130°C or higher, and contains 0.5-2.8 mass% of a higher fatty acid ester.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a cyclic olefin copolymer resin composition, and a molded article and an optical part using the resin composition. [Background technology]

[0002] BACKGROUND ART In recent years, there has been active development of devices such as virtual reality (hereinafter referred to as VR) and augmented reality (hereinafter referred to as AR). Specifically, an example is a VR head-mounted display that displays computer-generated images or images captured by a stereo camera on a display for each eye placed near the eye, and uses a magnifying optical system placed between the display and the eye to magnify the image from close to the viewing angle of the human eye to beyond, giving the user the feeling that they are actually present in the image space. Similarly, an example is an AR head-mounted display in which an image is incident on a transparent waveguide using mirrors, diffraction gratings, and holographic elements, guided by total reflection, and then outputted in the direction of the user's eyes using mirrors, diffraction gratings, and holographic elements arranged in a way that breaks the total reflection, thereby allowing the real world to be observed as see-through due to the transparent waveguide, while the image light is superimposed on the real world using the above optical system.

[0003] These devices must be able to be worn comfortably by the viewer and must display images that do not feel strange to the viewer. There is also a demand for the entire device to be lightweight, small, and thin, and for it to display images that are highly immersive.

[0004] For example, when it comes to images, the image light is magnified, so the low resolution of the display can cause a screen door effect, where a mesh pattern is visible. To solve this problem, high-resolution displays with a resolution of 4K or higher (hereinafter referred to as 4K displays) are used. However, because the image on a 4K display is enlarged for viewing by the user, the resolution is not sufficient for the actual experience. In response to demand for more immersive images, there is a need to develop head-mounted displays that can support even higher resolutions.

[0005] Regarding the viewing angle, particularly in VR head-mounted displays, the magnifying optical system must be thin yet have a strong magnification ratio in order to magnify the image beyond the viewing angle while preventing the device from becoming large and bulky. As such an optical system, for example, Patent Documents 1 to 3 propose eyepiece optical systems that fold the optical path by using polarized light.

[0006] The basic configuration is conceptually shown in Figure 1. The basic configuration combines a circular polarization element 102 (e.g., a linear polarizer and a 1 / 4λ element bonded together), a half mirror 103, a lens 104, a 1 / 4λ element, and a reflective polarization element 106 with the function of separating polarized light (e.g., an optical element that reflects S-waves perpendicular to the plane of incidence and transmits P-waves parallel to the plane of incidence). Here, light emitted from the image display device 101 is converted into circularly polarized light by the circular polarization element 102 and transmitted through the half mirror 103. After passing through the lens 104, the 1 / 4λ element 105 applies a phase difference to the light and converts it into linearly polarized light. At this time, by aligning the transmission axis of the reflective polarization element 106 perpendicular to the axis of this linear polarization, the light is reflected by the reflective polarization element 106, turns its optical path, and is converted back into circularly polarized light by the 1 / 4λ element 105. The light passes through the lens, is reflected again by the half mirror, and passes through the lens a third time, where it is converted into linearly polarized light by a 1 / 4λ element, with its polarization axis set to be such that it passes through the reflective optical element, and the user can view the image after passing through the reflective polarizing element 106. This type of configuration (hereinafter referred to as a pancake lens configuration) results in an optical system in which light is folded, increasing the magnification factor of the lens and allowing a thin optical system to be applied to a head-mounted display.

[0007] However, in such optical systems, light passes through the lens three times, which means that the contribution of birefringence is tripled. If the polarization axis is not strictly controlled, problems arise, such as ghosts and flares caused by the image that should be reflected by the reflective polarizing element being transmitted, and a decrease in contrast caused by the image that should be transmitted being reflected again. In particular, when resin lenses are used instead of glass to reduce the weight of head-mounted displays, orientation birefringence caused by the orientation of the main chain that occurs during resin injection molding, and the influence of photoelasticity caused by residual internal stress or externally applied stress, cause the polarization axis of image light to rotate, resulting in serious problems such as the occurrence of ghosts, flares, and reduced contrast (see, for example, Patent Documents 3 and 4). Therefore, in order to solve these problems, low-birefringence resins are being developed.

[0008] Cyclic olefin copolymers have been favorably used in optical components such as imaging lenses due to their excellent optical properties, low moisture absorption, mechanical properties, and thermal properties (see, for example, Patent Documents 5 and 6). On the other hand, transparent resins such as cyclic olefin copolymers have a cyclic structure in the main chain, which causes polarization in the main chain direction and positive orientation birefringence, but because they do not have structural units with polarization perpendicular to the main chain to offset this birefringence, the orientation birefringence tends to be large.Similarly, it has been difficult to strictly control the repeating unit structure so that the positive and negative polarities cancel each other out and the photoelastic coefficient is zero while maintaining heat resistance.

[0009] Therefore, in the case of cyclic olefin copolymers, efforts have been made to satisfy low birefringence characteristics by molding lenses under molding conditions that minimize the generation of orientation birefringence, while performing an annealing treatment to remove internal strain, thereby relaxing the internal strain and reducing photoelasticity.

[0010] However, there is a limit to how much birefringence can be reduced by changing the molding conditions of the resin alone. Increasing the cylinder temperature to reduce orientation birefringence can cause problems such as yellowing due to thermal degradation of the resin, and the inability to mold lenses according to the design drawings under harsh molding conditions.

[0011] In addition, as VR head-mounted displays generate heat during use, dimensional changes occur, such as expansion of the lenses, and stress is applied to the adhesive joint with the lens barrel, causing stress birefringence, which poses a problem when displaying clear images. [Prior art documents] [Patent documents]

[0012] [Patent Document 1] U.S. Patent No. 6,563,638 [Patent Document 2] Patent No. 6386210 [Patent Document 3] Japanese Patent Application Publication No. 2020-85956 [Patent Document 4] Patent Publication No. 2021-92767 [Patent Document 5] Japanese Patent Application Publication No. 2018-72665 [Patent Document 6] Japanese Patent Application Laid-Open No. 2009-256504 Summary of the Invention [Problem to be solved by the invention]

[0013] Therefore, the present invention aims to provide a cyclic olefin copolymer resin composition that can suppress the generation of foreign matter such as haze and poor appearance during molding, while keeping birefringence extremely low even at high temperatures, and that can produce optical components such as lenses with extremely low birefringence even without harsh molding conditions. [Means for solving the problem]

[0014] As a result of intensive research conducted by the inventors to solve the above-mentioned problems, they discovered that by adding a specific higher fatty acid ester to a cyclic olefin copolymer in an amount at least twice the amount blended in a general resin composition, fluidity is dramatically improved and orientation birefringence is suppressed, while the higher fatty acid ester moves freely at a specific temperature, promoting the movement of the ring skeleton and side chains extending from the main chain of the resin and working to relieve internal strain, thereby making it possible to significantly reduce internal strain alone without deteriorating the surface shape even during the annealing process. Furthermore, the obtained cyclic olefin copolymer resin composition is capable of maintaining a low photoelastic coefficient in high-temperature environments, and when used as a VR lens, it is less likely to experience stress birefringence even when thermal expansion occurs due to heat generation from the display. As a result, it has been found possible to provide a high-quality VR headset that is less likely to distort images over long periods of time. Furthermore, the inventors have discovered that by limiting the formulation amount of the higher fatty acid ester within a specific range, it is possible to suppress the generation of foreign matter such as haze during molding and poor appearance, and by suppressing a decrease in strength such as bending strength, it is possible to provide a cyclic olefin copolymer resin composition that can suppress the occurrence of cracks and the like even when an optical film is bonded to the curved surface of a lens, thereby completing the present invention.

[0015] The present invention is as follows. [1] A resin composition containing a copolymer of ethylene or an α-olefin and a cyclic olefin, The absolute value of the photoelastic coefficient measured at 110°C is 10.0 x 10 -12 Pa -1 is as follows: The glass transition temperature is 130°C or higher, The cyclic olefin copolymer resin composition further contains 0.5 to 2.8 mass % of a higher fatty acid ester. [2] The cyclic olefin copolymer resin composition according to [1], wherein the higher fatty acid ester has two or less hydroxy groups in the molecule. [3] The polyhydric alcohol constituting the higher fatty acid ester is pentaerythritol distearate. The cyclic olefin copolymer resin composition according to [1] or [2], [4] The cyclic olefin copolymer resin composition according to any one of [1] to [3], characterized in that the proportion of ring skeleton constituent units in the main chain of the cyclic olefin copolymer is 36 mol % or more and 50 mol % or less. [5] The repeating units derived from the cyclic olefin in the cyclic olefin copolymer are bicyclo[2.2.1]-2-heptene and tetracyclo[4.4.0.1 2,5 .1 7,10 1. A cyclic olefin copolymer resin composition according to any one of [1] to [4], characterized in that the repeating units are derived from at least one compound selected from 1-, 2-, 3-, 4-, 5-, 6-, 7-, 8-, 9-, 10-, 11-, 12-, 13-, 14-, 15-, 16-, 17-, 18-, 19-, [6] The cyclic olefin copolymer resin composition according to any one of [1] to [5], characterized in that the weight average molecular weight Mw is 70,000 to 100,000. [7] The cyclic olefin copolymer resin composition according to any one of [1] to [6], which has a flexural strength of 70 MPa or more. [8] The cyclic olefin copolymer resin composition according to any one of [1] to [6], which has a flexural strength of 80 MPa or more. [9] The specific gravity of the pellets made of the cyclic olefin copolymer resin composition is 1.0 g / cm 3 The cyclic olefin copolymer resin composition according to any one of [1] to [8], characterized in that:

[10] A lens comprising the cyclic olefin copolymer resin composition according to any one of [1] to [9], and used in an ocular optical system.

[11] A waveguide comprising the cyclic olefin copolymer resin composition according to any one of [1] to [9] and having a thickness of 1.0 mm or less.

[12] A prism comprising the cyclic olefin copolymer resin composition according to any one of [1] to [9]. [Effects of the Invention]

[0016] The cyclic olefin copolymer resin composition of the present invention has transparency, heat resistance, and a high refractive index. Furthermore, by undergoing a specific annealing step, it is possible to obtain a molded product with extremely low birefringence while maintaining surface precision. Furthermore, since the photoelastic coefficient at high temperatures is low and stress birefringence is unlikely to occur when a display or the like heats up, clear images can be viewed. Furthermore, the cyclic olefin copolymer resin composition of the present invention has good mechanical properties such as bending strength, and therefore, an optical lens having an optical film laminated thereon can be obtained that does not crack even after reliability tests such as constant temperature and humidity tests. [Brief explanation of the drawings]

[0017] [Figure 1] FIG. 1 is a conceptual diagram of an optical system with a pancake lens configuration. [Figure 2] FIG. 2 is a conceptual diagram showing an outline of an experimental setup for evaluating image contrast using an optical system with a pancake lens configuration. [Figure 3] FIG. 3 shows an example of experimental results showing that ghosts and flares occur when birefringence occurs in the lenses used in the configuration shown in FIG. [Figure 4] FIG. 4 illustrates the image display method used to evaluate the image contrast of FIG. DETAILED DESCRIPTION OF THE INVENTION

[0018] Below, we will explain in detail the form for implementing the present invention (hereinafter referred to as the "present embodiment"). However, the present invention is not limited to the following description and can be implemented in various modifications within the scope of its gist. Furthermore, in descriptions of the polarization state and phase difference of light, concepts such as linear polarization, circular polarization, elliptical polarization, and a 1 / 4λ phase difference generally refer to broad states having a certain range. Therefore, errors in these terms do not interfere with the essential effects of the present invention. Furthermore, the phase difference generated by each optical element is the phase difference for light of wavelength λ, and the wavelength λ can be selected from any wavelength in the visible light range, for example, λ = 587.6 nm, but is not limited to this. In this embodiment, "A to B" indicating a numerical range means A or more and B or less unless otherwise specified.

[0019] <Cyclic olefin copolymer resin composition> The cyclic olefin copolymer resin composition of the present embodiment (hereinafter, sometimes simply referred to as the "resin composition") is a resin composition containing a cyclic olefin copolymer (hereinafter, sometimes referred to as the "cyclic olefin copolymer resin"), which is a copolymer of ethylene or an α-olefin and a cyclic olefin.

[0020] (cyclic olefin copolymer) The cyclic olefin copolymer contained in the resin composition of this embodiment includes a copolymer having a repeating unit derived from a cyclic olefin as an essential constituent unit. The cyclic olefin polymer is a copolymer (A1) of ethylene or an α-olefin with a cyclic olefin.

[0021] The cyclic olefin copolymer contained in the resin composition of this embodiment preferably contains at least one repeating unit (b) derived from a cyclic olefin selected from the group consisting of repeating units represented by the following general formula (II), repeating units represented by the following general formula (III), and repeating units represented by the following general formula (IV). From the viewpoint of further improving heat resistance and improving moldability while maintaining a good performance balance between the transparency and refractive index of the obtained molded article, it is more preferable that the cyclic olefin copolymer contains at least one repeating unit (a) derived from an olefin represented by the following general formula (I), and at least one repeating unit (b) derived from a cyclic olefin selected from the group consisting of repeating units represented by the following general formula (II), repeating units represented by the following general formula (III), and repeating units represented by the following general formula (IV).

[0022] [ka] In the above general formula (I), R 300 is a hydrogen atom or a straight-chain or or a branched hydrocarbon group.

[0023] [ka] In the above general formula (II), u is 0 or 1, v is 0 or a positive integer, preferably an integer of 0 or more and 2 or less, more preferably 0 or 1, w is 0 or 1, and R 61 ~R 78 and R a1 and R b1 may be the same or different and are a hydrogen atom, a halogen atom, an alkyl group having 1 to 20 carbon atoms, a halogenated alkyl group having 1 to 20 carbon atoms, a cycloalkyl group having 3 to 15 carbon atoms, or an aromatic hydrocarbon group having 6 to 20 carbon atoms; R 75 ~R 78 may be bonded to each other to form a monocyclic or polycyclic ring.

[0024] [ka] In the above general formula (III), x and d are integers of 0 or 1 or more, preferably 0 or more. is an integer of 2 or less, more preferably 0 or 1, y and z are 0, 1 or 2, and R 81 ~R 99 may be the same or different and are a hydrogen atom, a halogen atom, an aliphatic hydrocarbon group which is an alkyl group having 1 to 20 carbon atoms or a cycloalkyl group having 3 to 15 carbon atoms, an aromatic hydrocarbon group having 6 to 20 carbon atoms, or an alkoxy group; R 89 and R 90 and the carbon atom to which R is bonded. 93 or the carbon atom to which R 91 may be bonded directly or via an alkylene group having 1 to 3 carbon atoms, and when y=z=0, R 95 and R 92 or R 95 and R 99 may be bonded to each other to form a monocyclic or polycyclic aromatic ring.

[0025] [ka] In the above general formula (IV), R 100 , R 101 may be the same or different from each other. It often represents a hydrogen atom or a hydrocarbon group having 1 to 5 carbon atoms, and f is 1≦f≦18.

[0026] Olefin Monomer The olefin monomer, which is one of the copolymerization raw materials for the cyclic olefin copolymer according to this embodiment, undergoes addition copolymerization to form the constitutional unit represented by the above general formula (I). Specifically, an olefin monomer represented by the following general formula (Ia) corresponding to the above general formula (I) is used.

[0027] [ka] In the above general formula (Ia), R 300 represents a hydrogen atom or a linear or branched hydrocarbon group having 1 to 29 carbon atoms. Examples of the olefin monomer represented by the general formula (Ia) include ethylene and α-olefins, and specific 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. Among these, ethylene or propylene is preferred, and ethylene is particularly preferred, from the viewpoint of obtaining a molded article having better heat resistance, mechanical properties, and optical properties. Two or more types of olefin monomers represented by the above general formula (Ia) may be used.

[0028] In this embodiment, when the total number of structural units constituting the cyclic olefin copolymer (A) is taken as 100 mol%, the proportion of olefin-derived repeating units (a) ((a) / (A)×100 mol%) is preferably 5 mol% or more and 95 mol% or less, more preferably 40 mol% or more and 85 mol% or less, even more preferably 50 mol% or more and 64 mol% or less, and particularly preferably 50 mol% or more and 62 mol% or less. The proportion of the repeating unit (a) derived from olefin is: 13 It can be measured by C-NMR.

[0029] Cyclic olefin monomer (b) The cyclic olefin monomer (b) constituting the cyclic olefin copolymer resin is not particularly limited, and examples thereof include the cyclic olefin monomers described in paragraphs 0037 to 0063 of WO 2006 / 0118261.

[0030] The cyclic olefin monomer (b), which is one of the copolymerization raw materials for the cyclic olefin copolymer (A) according to this embodiment, is preferably one that undergoes addition copolymerization to form a repeating unit (b) derived from a cyclic olefin represented by the general formula (II), (III), or (IV). Specifically, the cyclic olefin monomers (b) represented by the general formulas (IIa), (IIIa), and (IVa), which correspond to the general formulas (II), (III), and (IV), respectively, are used.

[0031] [ka]

[0032] In the above general formula (IIa), u is 0 or 1, v is 0 or a positive integer, preferably an integer of 0 or more and 2 or less, more preferably 0 or 1, w is 0 or 1, and R 61 ~R 78 and R a1 and R b1 may be the same or different and are a hydrogen atom, a halogen atom, an alkyl group having 1 to 20 carbon atoms, a halogenated alkyl group having 1 to 20 carbon atoms, a cycloalkyl group having 3 to 15 carbon atoms, or an aromatic hydrocarbon group having 6 to 20 carbon atoms; R 75 ~R 78 may be bonded to each other to form a monocyclic or polycyclic ring.

[0033] [ka]

[0034] In the above general formula (IIIa), x and d are 0 or an integer of 1 or more, preferably an integer of 0 or more and 2 or less, more preferably 0 or 1, y and z are 0, 1, or 2, and R 81 ~R 99may be the same or different and are a hydrogen atom, a halogen atom, an aliphatic hydrocarbon group which is an alkyl group having 1 to 20 carbon atoms or a cycloalkyl group having 3 to 15 carbon atoms, an aromatic hydrocarbon group having 6 to 20 carbon atoms, or an alkoxy group; R 89 and R 90 and the carbon atom to which R is bonded. 93 or the carbon atom to which R 91 may be bonded directly or via an alkylene group having 1 to 3 carbon atoms, and when y=z=0, R 95 and R 92 or R 95 and R 99 may be bonded to each other to form a monocyclic or polycyclic aromatic ring.

[0035] [ka]

[0036] In the above general formula (IVa), R 100 , R 101 may be the same or different and represent a hydrogen atom or a hydrocarbon group having 1 to 5 carbon atoms, and f is 1≦f≦18.

[0037] By using the olefin monomer represented by the general formula (Ia) or the cyclic olefin monomer (b) represented by the general formula (IIa), (IIIa) or (IVa) as the copolymerization component, the solubility of the cyclic olefin copolymer (A) in a solvent is further improved, resulting in good moldability and improved product yield.

[0038] Specific examples of the cyclic olefin monomer (b) represented by general formula (IIa), (IIIa) or (IVa) include the compounds described in paragraphs 0037 to 0063 of WO 2006 / 0118261.

[0039] Specifically, bicyclo-2-heptene derivatives (bicyclohept-2-ene derivatives), tricyclo-3-decene derivatives, tricyclo-3-undecene derivatives, tetracyclo-3-dodecene derivatives, pentacyclo-4-pentadecene derivatives, pentacyclopentadecadiene derivatives, pentacyclo-3-pentadecene derivatives, pentacyclo-4-hexadecene derivatives, pentacyclo-3-hexadecene derivatives, hexacyclo-4-heptadecene derivatives, and heptacyclo-5-eicosene derivatives, heptacyclo-4-eicosene derivatives, heptacyclo-5-heneicosene derivatives, octacyclo-5-docosene derivatives, nonacyclo-5-pentacosene derivatives, nonacyclo-6-hexacosene derivatives, cyclopentadiene-acenaphthylene adducts, 1,4-methano-1,4,4a,9a-tetrahydrofluorene derivatives, 1,4-methano-1,4,4a,5,10,10a-hexahydroanthracene derivatives, and cycloalkylene derivatives having 3 to 20 carbon atoms.

[0040] Among the cyclic olefin monomers (b) represented by general formula (IIa), (IIIa) or (IVa), the cyclic olefin represented by general formula (IIa) is preferred. Examples of the cyclic olefin monomer (b) represented by the general formula (IIa) include bicyclo[2.2.1]-2-heptene (also called "norbornene"), tetracyclo[4.4.0.1 2,5 .1 7,10 ]-3-dodecene (also called tetracyclododecene) is preferably used, and tetracyclo[4.4.0.1 2,5 .1 7,10 It is more preferable to use ]-3-dodecene. These cyclic olefins have a rigid ring structure, which is advantageous in that the elastic modulus of the copolymer and the molded article can be easily maintained.

[0041] When the total number of structural units constituting the main chain of the cyclic olefin copolymer (A) is taken as 100 mol%, the proportion of repeating units (ring skeleton structural units) (b) derived from the cyclic olefin monomer (b) ((b) / (A)×100 mol%) is preferably 5 mol% or more and 95 mol% or less, more preferably 15 mol% or more and 60 mol% or less, even more preferably 36 mol% or more and 50 mol% or less, and particularly preferably 38 mol% or more and 50 mol% or less. By setting the repeating unit (b) derived from the cyclic olefin monomer (b) within the above range, high heat resistance is imparted and a high elastic modulus is maintained, particularly even in high temperature regions, thereby suppressing shape deformation during the annealing process and making it possible to minimize surface deformation in optical lenses, prisms, etc.

[0042] The molecular weight of the cyclic olefin copolymer (A) according to this embodiment is not particularly limited, but is preferably a molecular weight that exhibits an intrinsic viscosity [η] measured in decalin at 135°C of 0.03 dl / g to 10 dl / g, more preferably 0.05 dl / g to 5 dl / g, and even more preferably 0.10 dl / g to 2 dl / g. When the molecular weight of the cyclic olefin copolymer (A) is equal to or greater than the lower limit, the mechanical strength of the molded article can be improved, and when the molecular weight is equal to or less than the upper limit, the moldability can be improved.

[0043] The resin composition according to the present embodiment is composed of a resin composition containing a thermoplastic resin such as a cyclic olefin copolymer. The resin composition may be a thermoplastic resin alone, or may be a mixture further containing other components (for example, additives described below).

[0044] (higher fatty acid esters) The cyclic olefin copolymer resin composition according to this embodiment contains a higher fatty acid ester in addition to the above-mentioned cyclic olefin copolymer (A).

[0045] The intended function of the present invention can be achieved by adding a specific amount of higher fatty acid ester to the cyclic olefin copolymer resin composition according to this embodiment. Furthermore, it is preferable to use a higher fatty acid ester having two or less hydroxy groups in the molecule as the higher fatty acid ester, since this allows for the production of optical components with small haze and good optical properties.

[0046] Furthermore, the content of higher fatty acid ester in the cyclic olefin copolymer resin composition according to this embodiment must be 0.5% by mass or more and 2.8% by mass or less, preferably 0.6% by mass or more and 2.5% by mass or less, 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. By mixing the higher fatty acid ester in the above range, the fluidity of the resin is dramatically improved and orientation birefringence is alleviated, and the higher fatty acid alone moves at temperatures near its melting point, promoting relaxation of the resin side chains and working to alleviate internal strain. Even in the annealing process, internal strain alone can be significantly reduced without deteriorating the surface shape. In addition, by controlling the formulation amount of the higher fatty acid ester within the above range, it is possible to suppress the occurrence of foreign matter such as haze and other defects in appearance during molding, thereby maintaining high shape precision of the molded product, and further to suppress the occurrence of staining of the mirror surface of the mold insert and clogging of the gas vent during molding.

[0047] Here, the higher fatty acid ester is an ester compound composed of a fatty acid having 6 or more carbon atoms and an alcohol. The higher fatty acid ester according to this embodiment is composed of the following polyhydric alcohol and fatty acid. Examples of the polyhydric alcohol include glycerin, pentaerythritol, diglycerin, triglycerin, polyglycerin, 1,2-ethanediol, dipentaerythritol, sorbitan, polyethylene glycol, polypropylene glycol, polybutylene glycol, α,α'-[(isopropylidene)di-4,1-phenylene]bis{ω-hydroxy-poly[oxy(methylethylene)]}, polyoxyethylene-laurylamine, polyoxyethylene-stearylamine, polyoxyethylene-oleylamine, polyoxyethylene polyoxypropylene pentaerythritol ether, polyethylene glycol polybutylene glycol pentaerythritol ether, poly Examples of the polyoxyethylene glycol include oxytetramethylene 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 diglycerol ether, polyoxypropylene sorbitol, polyoxybutylene polyoxyethylene pentaerythritol ether, polyoxyethylene methyl glucoside, and polyoxypropylene methyl glucoside. Examples of the fatty acids include saturated fatty acids such as hexanoic acid, heptanoic acid, octanoic acid, nonanoic acid, capric 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, elaidic acid, gadoleic acid, and eicosenoic acid; diunsaturated fatty acids such as linoleic acid, eicosadienoic acid, and docosadienoic acid; triunsaturated fatty acids such as linolenic acid, pinolenic acid, eleostearic acid, and eicosatrienoic acid; and tetraunsaturated fatty acids such as stearidonic acid, arachidonic acid, and eicosatetraenoic acid. Furthermore, in consideration of industrial uniformity when synthesizing or obtaining higher fatty acid esters, the additive is preferably a polyhydric alcohol having a high symmetry among polyhydric alcohols. Specifically, a polyhydric alcohol having a symmetry higher than C2 or C3 is preferred, more preferably a polyhydric alcohol having a symmetry higher than C2 or C3 and having no stereoisomers, even more preferably a polyhydric alcohol having a symmetry higher than C2 or C3 and having no stereoisomers, in which all hydroxy groups are equivalent, and particularly preferably pentaerythritol.

[0048] As mentioned above, the higher fatty acid ester preferably has two or less OH groups (hydroxy groups) in the molecule. By using a higher fatty acid ester with such a molecular structure, good dispersion in the resin composition is maintained and cloudiness, which can cause haze deterioration, is unlikely to occur. In addition, mold contamination due to bleeding during molding can be suppressed.

[0049] The higher fatty acid ester preferably has a melting point of 0° C. or higher, more preferably 10° C. or higher, even more preferably 25° C. or higher, and particularly preferably 35° C. or higher. When the melting point is in this temperature range, relaxation is unlikely to occur in a room temperature environment, and mold contamination due to bleed-out during molding and a decrease in mechanical strength can be suppressed.

[0050] The melting point of the higher fatty acid ester is the glass transition temperature (Tg 樹脂 ) more than 10℃ lower (Tg 樹脂 It is preferable that the melting point is -10°C or less, and more preferably Tg 樹脂 -20°C, particularly preferably Tg 樹脂 A melting point of -30°C or less is preferred. When the melting point of the higher fatty acid ester is in this temperature range, the shape of the molded body is less likely to change in the high temperature range where the main chain of the resin relaxes, and mold contamination due to bleed-out during molding can be suppressed. Furthermore, in an annealing process at a temperature range about 40°C lower than the glass transition temperature of the resin composition, deformation of the molded body can be suppressed, but the effect of alleviating birefringence is usually small. However, by using a higher fatty acid ester with a melting point in the above temperature range, the temperature is above the melting point and so it can move freely, promoting relaxation of the ring skeleton and side chains extending from the main chain of the resin, which can effectively reduce birefringence.

[0051] (Other additives) The cyclic olefin copolymer resin composition according to this embodiment may contain various additives as needed within the range that does not significantly impair the effects of the present invention. The additives are not particularly limited, and examples thereof include, in addition to the higher fatty acid esters, weathering stabilizers, heat stabilizers, antioxidants, light stabilizers such as hindered amine-based light stabilizers, ultraviolet absorbers, release agents, lubricants, thermoplastic resins other than cyclic olefin copolymers, metal deactivators, hydrochloric acid absorbers, slip agents, antiblocking agents, antifogging agents, softeners such as synthetic oils, paraffins, organic polysiloxanes, and mineral oils, plasticizers, flame retardants, antistatic agents, inorganic fillers such as organic fibers and pigments such as iron oxides, reinforcing materials such as glass fibers, carbon fibers, and metal whiskers, colorants, organic phosphorus compounds such as phosphites, phosphonites, and phosphate esters, other additives, and mixtures thereof.

[0052] -Glass transition temperature- The cyclic olefin copolymer resin composition according to the present embodiment preferably has a glass transition temperature (Tg) of 115° C. or more and 160° C. or less, more preferably 125 to 155° C., even more preferably 130 to 150° C., particularly preferably 135 to 150° C., and most preferably 140 to 150° C. The glass transition temperature can be measured by the midpoint method in accordance with JIS-K7121. The resin composition has a glass transition temperature of 115°C or higher, ensuring heat resistance even in high-temperature environments such as those generated by electronic devices in head-mounted displays and in some outdoor and in-vehicle environments. Furthermore, this is preferable because it can suppress photoelastic birefringence caused by tension at the bonding interface when a reflective polarizing element and a resin lens are bonded together.

[0053] On the other hand, when the glass transition temperature (Tg) of the cyclic olefin copolymer resin composition in this embodiment is 160°C or less, melt processing at extremely high temperatures can be avoided, thermal decomposition of the resin, etc. can be suppressed, and a good product can be obtained. The glass transition temperature (Tg) is preferably 155°C or less, more preferably 150°C or less, and even more preferably 140°C or less, in order to further obtain the above-mentioned effects. Furthermore, when the glass transition temperature of the cyclic olefin copolymer resin composition of this embodiment exceeds 160°C, the mold temperature needs to be kept high in the injection molding step described below in order to reduce the birefringence of the resin lens. However, when the resin lens is removed, a long cooling time needs to be taken in order to suppress deformation such as sink marks, lengthening the cycle time. In addition, rapid cooling due to the temperature difference from room temperature is likely to leave distortion in the resin lens, which is undesirable from the viewpoint of sufficiently reducing the birefringence of the resin lens.

[0054] -Photoelastic coefficient CR- The absolute value |CR| of the photoelastic coefficient CR of the cyclic olefin copolymer resin composition according to this embodiment is 10.0 × 10 -12 Pa -1 It can be less than or equal to 7.0×10 -12 Pa -1 or less, and more preferably 6.0 × 10 -12 Pa -1 or less, and more preferably 5.0 × 10 -12 Pa -1 It is particularly preferably 3.0 × 10 -12 Pa -1 The following is the result. The photoelastic coefficient is described in various documents (for example, see Chemical Review, No. 39, 1998 (published by the Academic Society Publishing Center)) and is defined by the following formulas (ia) and (ib): The closer the value of the photoelastic coefficient CR is to zero, the smaller the change in birefringence due to external force is. |CR|=|Δn| / σR (ia) |Δn|=|nx-ny| (ib) (In the formula, CR is the photoelastic coefficient, σR is the tensile stress, |Δn| is the absolute value of birefringence, nx is the refractive index in the stretching direction, and ny is the refractive index in the in-plane direction perpendicular to the stretching direction.) Therefore, the absolute value |CR| of the photoelastic coefficient CR of the resin composition is set to 10.0 × 10 -12 Pa -1 By satisfying the following conditions, it is possible to obtain a resin lens in which birefringence caused by internal strain generated during molding and stress birefringence caused by stress generated when fixing and adhering the lens to a lens barrel or jig are sufficiently small, thereby suppressing the occurrence of ghosts and deterioration of contrast in optical devices that use polarized light and providing clear images. The photoelastic coefficient CR can be measured by the method described in the examples below.

[0055] -Photoelastic coefficient CR under high temperature environment- The absolute value |CR| of the photoelastic coefficient CR of the cyclic olefin copolymer resin composition according to this embodiment in a 110°C environment is 10.0 × 10 -12 Pa -1 It is necessary that the density is equal to or less than 7.0×10 -12 Pa -1 or less, and more preferably 6.0 × 10 -12 Pa -1 or less, and more preferably 5.5 × 10 -12 Pa -1 or less, and particularly preferably 4.8x10 -12 Pa -1 The following is the result. By using a cyclic olefin copolymer resin composition within the above range, stress birefringence near the adhesive joint with the lens barrel, which occurs due to thermal expansion of the molded product in high-temperature environments or due to heat generation from the device, can be kept low, and as a result, a high-quality VR headset can be provided that is less likely to distort images over long periods of time. The photoelastic coefficient CR under a high temperature environment can be measured in a thermostatic chamber in the same manner as the above-mentioned method for measuring the photoelastic coefficient CR.

[0056] The absolute value of the photoelastic coefficient can be adjusted, for example, by adjusting the copolymerization composition ratio of the α-olefin-derived structural unit and the cyclic olefin-derived structural unit within an appropriate range, to obtain a cyclic olefin copolymer resin composition having a small absolute value of the photoelastic coefficient.

[0057] -Molecular weight and molecular weight distribution- The cyclic olefin copolymer resin composition according to this embodiment has a weight average molecular weight (Mw) in terms of polystyrene measured by gel permeation chromatography (GPC) in the range of preferably 50,000 to 170,000, more preferably 60,000 to 170,000, even more preferably 70,000 to 130,000, still more preferably 70,000 to 100,000, and particularly preferably 80,000 to 95,000. This is because the weight-average molecular weight (Mw) in the above range provides an excellent balance between mechanical strength and fluidity. However, if Mw is less than 80,000, mechanical properties such as bending strength will be reduced, and cracks may occur due to tension such as bending stress when an optical film such as a polarizing plate is attached to an optical component such as a lens, which is undesirable. Furthermore, the resin composition according to this embodiment has a broad molecular weight distribution due to a peak in the low molecular weight region derived from the higher fatty acid ester. Therefore, the molecular weight distribution Mw / Mn, which is the ratio of Mw to the number average molecular weight (Mn), is preferably in the range of 3.0 to 8.0, more preferably 4.0 to 7.0, and even more preferably 5.0 to 6.5. By having the ratio in this range, the flowability can be dramatically improved, the transferability during molding can be improved, and lenses with excellent surface precision can be obtained.

[0058] The weight average molecular weight (Mw), number average molecular weight (Mn), and Z average molecular weight (Mz) of the resin composition can be measured using the following apparatus and conditions. Measurement equipment: Agilent (PL-GPC220) Measurement conditions: Column: Two TSKguard column GMHHR-H(20)HT (7.8mm I.D. x 30cm) connected in series and use it. Column temperature: 145℃ Developing solvent: o-dichlorobenzene, containing 0.05% 2,6-di-t-butyl-4-methylphenol (BHT). Detector: RI (differential refractive index) detector Detection sensitivity: 3.0 mV / min Sample: The sample was weighed into a high-temperature filter so that the solution concentration was 1 mg / mL, 5 mL of eluent was added, and the mixture was heated at 145°C for 30 minutes and then shaken for 1 hour to dissolve the sample. Injection volume: 500μL Flow rate: 0.7mL / min Standard samples for the calibration curve: Use the following 10 types of polystyrene, each with a known monodisperse weight peak molecular weight and different molecular weights. Weight peak molecular weight (Mw) Standard sample 1 6,570,000 Standard sample 2 2,703,000 Standard sample 3 729,500 Standard sample 4 301,600 Standard sample 5 133,500 Standard sample 6 70,500 Standard sample 7 27,810 Standard sample 8 9,570 Standard sample 9 3,090 Standard sample 10 580 Under the above conditions, the RI detection intensity is measured against the elution time of the resin lens. Based on the calibration curves obtained by measuring the standard samples for the calibration curves, the weight average molecular weight (Mw), number average molecular weight (Mn), and Z average molecular weight (Mz) of the resin are determined, and the molecular weight distributions (Mw / Mn) and (Mz / Mw) are determined using these values.

[0059] -Melt flow rate- The cyclic olefin copolymer resin composition used in this embodiment preferably has low viscosity and high fluidity in a state equivalent to that at the time of injection, in order to improve the transferability of the lens shape. Specifically, the melt flow rate of the resin composition of this embodiment, as measured at 260°C under a load of 2.16 kg, is preferably in the range of 30 g / 10 min to 70 g / 10 min, more preferably 40 to 65 g / 10 min, and even more preferably 45 to 60 g / 10 min. By controlling the melt flow rate within these ranges, it is possible to suppress the occurrence of orientation birefringence while ensuring fluidity during injection molding, even in thin-walled molded articles. It is also possible to prevent dripping of the molten resin from the nozzle of the injection molding machine, thereby suppressing molding defects.

[0060] -Storage modulus at high temperatures- In order to reduce birefringence when applied to plastic optical components, the cyclic olefin copolymer resin composition used in this embodiment is preferably subjected to the annealing process described in JP 2020-185742 A to relieve residual stress. At this time, annealing is performed at a first heat treatment temperature of Tg-15°C to Tg-2°C of the resin composition, and by maintaining a high storage modulus at this time, deterioration of the surface precision of the lens shape can be suppressed. A preferred value for the elastic modulus in such a high temperature range is a storage elastic modulus of 1800 MPa or more, more preferably 2000 MPa or more, and even more preferably 2300 MPa or more in a temperature range of Tg-15° C. When the storage elastic modulus is in this range, deformation of the lens shape in the first heat treatment step can be reduced. The storage modulus is a value measured in accordance with ISO 6721-4, and specifically, can be measured by the method described in the examples below.

[0061] -Bending strength- The cyclic olefin copolymer resin composition used in this embodiment may be used as an optical film laminated to a reflective polarizing element or the like after molding, such as in a resin lens. In this case, the resin lens and the reflective polarizing element each expand or shrink due to heat or water absorption, and the difference in dimensional change at this time generates bending stress. This may cause cracks or breaks in the resin lens of the reflective polarizing element-laminated lens. To prevent such defects (cracks or breaks), the resin composition of this embodiment preferably has high bending strength. Specifically, the bending strength is preferably 70 MPa or more, more preferably 75 MPa or more, even more preferably 80 MPa or more, and particularly preferably 85 MPa or more. When the bending strength is within these ranges, cracks and the like are less likely to occur in the resin lens even when the reflective polarizing element-bonded lens is subjected to a reliability test. The bending strength is a value measured in accordance with ISO 178, and specifically, can be measured by the method described in the examples below.

[0062] -Flexural modulus- When the cyclic olefin copolymer resin composition used in this embodiment is applied to a resin lens or a reflective polarizing element, it expands or contracts due to heat or water absorption, respectively, and the difference in dimensional change at this time causes bending stress. As a result, the resin lens of the reflective polarizing element-bonded lens may not maintain the shape as designed and may become deformed. To prevent such defects, it is preferable that the bending modulus of the resin composition of this embodiment is large. Specifically, the flexural modulus is preferably 2500 MPa or more, more preferably 3000 MPa or more, even more preferably 3200 MPa or more, and particularly preferably 3300 MPa or more. When the flexural modulus is within this range, even when an optical film such as a reflective polarizing element is attached to the curved surface of the lens, the surface shape of the resin lens is less likely to be distorted by bending stress before and after a reliability test. The flexural modulus is a value measured in accordance with ISO 178, and specifically, can be measured by the method described in the examples below.

[0063] <Pellets> A method for obtaining pellets according to an embodiment of the present invention will now be described. The pellets according to this embodiment are made of the cyclic olefin copolymer resin composition according to this embodiment, and can be obtained, for example, by extruding the resin composition in a molten state from the die or nozzle of an extruder in the form of strands, cooling and solidifying the strands in a water bath, and then cutting them into the desired particle size using a pelletizer.

[0064] In addition, fine chips generated by chipping or cracking during pelletizing may not melt in the screw when a molded product is obtained, remaining in the molded product and potentially becoming foreign matter. Therefore, underwater cutting, in which the strand is cut in a high-temperature molten state, is a suitable method for obtaining pellets. However, pellets obtained by underwater cutting are prone to voids forming inside the pellets upon cooling, and the air contained in the voids can cause oxidative degradation of the resin during molding, resulting in the generation of burnt foreign matter within the molding machine. Therefore, a more preferable method is to cool the strand obtained from the extruder in a water bath, then lift the strand into the atmosphere and cut it in a pelletizer. To prevent the generation of chips, methods can be used in which the temperature of the water bath and the position and height of a guide to prevent strand disturbance are adjusted to control the temperature of the strand before sending it to the pelletizer, or a sieve-based particle size classification method.

[0065] <Molded bodies and optical components> Next, the molded article according to the embodiment of the present invention will be described. The molded article according to this embodiment contains the cyclic olefin copolymer resin composition according to this embodiment. The molded article according to this embodiment contains the cyclic olefin copolymer resin composition according to this embodiment, and therefore has an excellent balance of transparency and refractive index. Therefore, it can be suitably used as an optical component in an optical system that requires highly accurate image identification. Optical components are components used in optical equipment, and specific examples include fθ lenses, imaging lenses, sensor lenses, prisms, light guide plates, waveguides, and eyepieces. In particular, since the cyclic olefin copolymer resin composition according to this embodiment is included, it has low birefringence and excellent heat resistance, and can suppress the occurrence of stress birefringence in high-temperature environments, so that stress birefringence is unlikely to occur even in environments where heat is generated by displays of VR headsets, AR headsets, etc., or chips such as CPUs and GPUs, and high-definition images can be displayed. Therefore, it is particularly suitable for prisms, waveguides, and eyepieces used in VR headsets and AR headsets.

[0066] When the molded article according to the present embodiment is used for optical applications, it is essential that the molded article transmits light, and therefore it is preferable that the molded article have a good light transmittance. The light transmittance is defined as a spectral light transmittance or a total light transmittance depending on the application.

[0067] -Light transmittance of molded body- When the molded article of this embodiment is expected to be used in all light or multiple wavelength ranges, it is necessary for the molded article to have a high total light transmittance, and the total light transmittance when no anti-reflection film is provided on the surface is 85% or more, preferably 88 to 93%. A total light transmittance of 85% or more can ensure the necessary amount of light. Known methods can be used to measure the total light transmittance, and the measuring device is not limited. For example, a method in accordance with ASTM D1003 can be used in which the cyclic olefin copolymer resin composition of this embodiment is molded into a sheet with a thickness of 3 mm, and the total light transmittance of the sheet obtained by molding the cyclic olefin resin composition of this embodiment is measured using a haze meter.

[0068] -Light transmittance of molded body- Furthermore, in the case of an optical system used only in a specific wavelength range, such as a laser optical system, the molded article of this embodiment can be used even if the total light transmittance is not high, as long as the spectral light transmittance in that wavelength range is good. In this case, the spectral light transmittance at the wavelength used without an anti-reflection film on the surface is preferably 85% or more, more preferably 86% to 93%. A spectral light transmittance of 85% or more can ensure the necessary amount of light. Furthermore, known methods and devices can be used for measurement, and a specific example is a spectrophotometer.

[0069] Furthermore, the molded article according to this embodiment has excellent light transmittance for light with a wavelength of 450 nm to 800 nm. When used as an optical component, the light transmittance can be further improved by providing a known anti-reflection film on the surface.

[0070] - Shape of molded body - The molded article according to this embodiment can be used in various forms such as a sphere, a rod, a plate, a column, a cylinder, a tube, a fiber, a film, or a sheet. The method for molding the cyclic olefin copolymer resin composition according to this embodiment to obtain a molded article is not particularly limited, and known methods can be used. Depending on the application and shape, for example, extrusion molding, injection molding, inflation molding, blow molding, extrusion blow molding, injection blow molding, press molding, vacuum molding, powder slush molding, calendar molding, foam molding, etc. can be applied. Among these, injection molding is preferred from the viewpoints of moldability and productivity. Furthermore, molding conditions can be appropriately selected depending on the intended use or molding method. For example, the resin temperature during injection molding is typically selected from the range of 150°C to 400°C, preferably 200°C to 350°C, and more preferably 230°C to 330°C.

[0071] When the molded article according to this embodiment is used as a lens, its shape is not particularly limited. It is preferable that the molded article is flat or has a convex or concave surface in the region including the optical axis of the lens. In addition to the lens portion, it may have a convex or concave portion for fixing to the housing. The shape of the lens may be spherical, aspherical, or free-form within the effective diameter. It may also be cylindrical, forming a curved surface only in one axis.

[0072] The size of the lens is not particularly limited, but is preferably Φ10 mm or more and Φ100 mm or less, more preferably Φ20 mm or more and Φ80 mm or less, and even more preferably Φ25 mm or more and Φ60 mm or less.

[0073] The shape of the lens within its effective diameter can be expressed using the radius of curvature R (unit: mm). The lens has a first surface and a second surface opposite each other, each defined with a radius of curvature R. When a circle of radius R is drawn from the center of curvature outside the lens, a portion of the circumference defines the lens surface shape. In this case, the line connecting the centers of curvature of the first surface and the second surface of the lens is defined as the optical axis of the lens. The radius of curvature of the lens is expressed as a positive number when the first surface side of the optical axis is convex or the second surface is concave toward the first surface side, whereas the radius of curvature is expressed as a negative number when the first surface is concave or the second surface is convex toward the second surface side. In the present invention, the radius of curvature R that defines the lens shape is not particularly limited. Except for the case where the lens is flat (absolute value of the radius of curvature R = ∞), the absolute value of the radius of curvature R is preferably 10 mm or more and 500 mm or less, more preferably 20 mm or more and 300 mm or less, and particularly preferably 30 mm or more and 200 mm or less. By using a shape within this range, the lens can be molded with a high yield. When the spherical surface of the resin lens is aspherical, the surface shape can be a rotationally symmetric aspherical surface in which the amount of sag z of the surface complies with the following equation 1.

number

[0074] Although the embodiments of the present invention have been described above, these are merely examples of the present invention, and various other configurations can also be adopted. Furthermore, the present invention is not limited to the above-described embodiment, and modifications and improvements within the scope of achieving the object of the present invention are included in the present invention. [Example]

[0075] The present invention will be explained in more detail below with reference to examples, but the present invention is not limited to these examples in any way.

[0076] [Examples 1 to 9 and Comparative Examples 1 to 7] In each of the examples and comparative examples, various physical properties were measured or evaluated by the following methods, and the results are shown in Table 2.

[0077] The raw materials used in the examples and comparative examples described later are shown below. (1) Additives Pentaerythritol tetrakis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate]: BASF "Irganox 1010" Pentaerythritol distearate: NOF Corporation "Unistar H-476D" Pentaerythritol tetrastearate: NOF Corporation "Unistar H-476" Pentaerythritol monostearate: Kao Corporation's "Excepearl PE-MS" Diglycerin stearate: "Rikemal S-71-D" manufactured by Riken Vitamin Co., Ltd. Ester of triglycerin and oleic acid: A distilled mixture is used. As the triglycerin fatty acid ester, for example, the compounds described in JP-A Nos. 2006-232714, 2002-275308, and 10-165152 can be used.

[0078] (2) Cyclic olefin copolymer Here, the following cyclic olefin copolymer (A) was synthesized by a method similar to the synthesis example described in the examples of WO 2008 / 068897.

[0079] Synthesis Example 1: Cyclic olefin copolymer (A) First, VO(OC2H5)Cl2 was diluted with cyclohexane to prepare a vanadium catalyst with a vanadium concentration of 6.7 mmol / L in cyclohexane.1.5 Cl 1.5 ) was diluted with cyclohexane to prepare an organoaluminum compound catalyst having an aluminum concentration of 107 mmol / L-hexane. Then, ethylene and tetracyclo[4.4.0.1] were continuously polymerized in a stirred polymerization vessel (inner diameter 500 mm, reaction volume 100 L). 2,5 .1 7,10 A copolymerization reaction with ]-3-dodecene was carried out. Here, ethylene was supplied into the polymerization reactor together with hydrogen gas. The flow rate of hydrogen gas was adjusted to obtain the desired molecular weight. When carrying out this copolymerization reaction, the vanadium catalyst prepared by the above method was supplied into the polymerization reactor in an amount such that the vanadium catalyst concentration relative to the cyclohexane used as the polymerization solvent in the polymerization reactor was 0.6 mmol / L. In addition, ethyl aluminum sesquichloride, an organoaluminum compound, was supplied into the polymerization reactor in an amount such that Al / V = 18.0. The polymerization temperature was set to 8°C, and the polymerization pressure was set to 1.8 kg / cm. 2 G was continuously copolymerized. Ethylene and tetracyclo[4.4.0.1 2,5 .1 7,10 To the copolymer solution of ethylene and tetracyclo[4.4.0.1]-3-dodecene, water and a 25% by mass aqueous solution of sodium hydroxide as a pH adjuster were added to terminate the polymerization reaction. The catalyst residues present in the copolymer were removed (decalcified) from the copolymer solution. 2,5 .1 7,10 Irganox 1010 was added as a stabilizer to a cyclohexane solution (polymer concentration 7.7% by mass) of a copolymer of 1-3-dodecene and 2-isopropyl-2-propanediol (2-isopropyl-2-propanediol) in an amount of 0.4 parts by mass per 100 parts by mass of the copolymer. Then, before entering the flash drying process, the mixture was temporarily dried in a 1.0 m 3 The mixture was mixed for 1 hour using a stirring tank. 20kg / cm as heat source 2A cyclohexane solution of the copolymer, with the concentration of the copolymer in the cyclohexane solution set to 5% by mass, was supplied at a rate of 150 kg / h to a double-pipe heater (outer pipe diameter 2B, inner pipe diameter 3 / 4B, length 21 m) using G steam, and heated to 180°C. 25kg / cm as heat source 2 Using a double-tube flash dryer (outer tube diameter 2B, inner tube diameter 3 / 4B, length 27m) and a flash hopper (volume 200L) using G steam, most of the unreacted monomers were removed from the cyclohexane solution of the copolymer that had undergone the heating process, along with the polymerization solvent cyclohexane, to obtain flash-dried molten ethylene and tetracyclo[4.4.0.1 2,5 .1 7,10 A random copolymer (cyclic olefin copolymer) with ]-3-dodecene was obtained. The cyclic olefin copolymer was extruded using a vented twin-screw kneading extruder and pelletized using an underwater pelletizer attached to the extruder outlet. The resulting pellets were dried with hot air at a temperature of 100°C for 4 hours to obtain cyclic olefin copolymer (A). The composition ratio of the cyclic olefin copolymer (A) is 13 C-NMR measurement confirmed that the ratio of CH to CH2 was such that the specified amount of olefin was copolymerized in a molar ratio of 60-67% and cyclotetracyclo[4.4.0.12,5.17,10]-3-dodecene in a ratio of 33-40%.

[0080] The weight average molecular weight of the resulting cyclic olefin copolymer (A) was measured by GPC and calculated as a standard polystyrene equivalent value. The GPC measurement was carried out under the following conditions. Measurement equipment: Agilent (PL-GPC220) Measurement conditions: Column: Two TSKguard column GMHHR-H(20)HT (7.8mm I.D. x 30cm) connected in series and use it. Column temperature: 145℃ Developing solvent: o-dichlorobenzene, containing 0.05% 2,6-di-t-butyl-4-methylphenol (BHT). Detector: RI (differential refractive index) detector Detection sensitivity: 3.0 mV / min Sample: The sample was weighed into a high-temperature filter so that the solution concentration was 1 mg / mL, 5 mL of eluent was added, and the mixture was heated at 145°C for 30 minutes and then shaken for 1 hour to dissolve the sample. Injection volume: 500μL Flow rate: 0.7mL / min Standard samples for the calibration curve: Use the following 10 types of polystyrene, each with a known monodisperse weight peak molecular weight and different molecular weights. Weight peak molecular weight (Mw) Standard sample 1 6,570,000 Standard sample 2 2,703,000 Standard sample 3 729,500 Standard sample 4 301,600 Standard sample 5 133,500 Standard sample 6 70,500 Standard sample 7 27,810 Standard sample 8 9,570 Standard sample 9 3,090 Standard sample 10 580 Under the above conditions, the RI detection intensity is measured against the elution time of the resin lens. Based on the calibration curves obtained by measuring the standard samples for the calibration curves, the weight average molecular weight (Mw), number average molecular weight (Mn), and Z average molecular weight (Mz) of the resin are determined, and the molecular weight distributions (Mw / Mn) and (Mz / Mw) are determined using these values.

[0081] <Preparation of Cyclic Olefin Copolymer Resin Composition> The components were melt-kneaded in the amounts shown in Table 2 using an OMega30H (screw diameter 30 mm, L / d=60) manufactured by STEER JAPAN to obtain samples of cyclic olefin copolymer resin compositions for each of the Examples and Comparative Examples.

[0082] Example 1 100 parts by mass of cyclic olefin copolymer (A) was dry-blended with 0.8 parts by mass of pentaerythritol distearate, a fatty acid ester composed of a tetrahydric alcohol and a fatty acid. The resulting blend pellets were fed into the hopper of a vented twin-screw extruder (screw diameter 30 mm, L / D = 60, manufactured by Omega Corporation) under a nitrogen atmosphere and kneaded at a cylinder temperature of 250°C and a resin pressure rate of 10 kg / h. After water cooling in a water bath, the mixture was pelletized using a pelletizer. The weight average molecular weight of the obtained pellets was 90,000, and the residual amount of pentaerythritol distearate was 0.6 wt%. Other properties are shown in the table.

[0083] Example 2 Pellets were obtained in the same manner as in Example 1, except that the amount of pentaerythritol distearate dry blended as a compounding additive was 1.5 parts by mass. The weight average molecular weight of the obtained pellets was 85,000, and the residual amount of pentaerythritol distearate was 1.3 wt%. Other properties are shown in the table.

[0084] Example 3 Pellets were obtained in the same manner as in Example 1, except that the amount of pentaerythritol distearate dry blended as a compounding additive was 1.1 parts by mass. The weight average molecular weight of the obtained pellets was 80,000, and the residual amount of pentaerythritol distearate was 0.9 wt%. Other properties are shown in the table.

[0085] Example 4 Pellets were obtained in the same manner as in Example 1, except that the amount of pentaerythritol distearate dry blended as a compounding additive was 1.5 parts by mass. The weight average molecular weight of the obtained pellets was 94,000, and the residual amount of pentaerythritol distearate was 1.3 wt%. Other properties are shown in the table.

[0086] Example 5 Pellets were obtained in the same manner as in Example 1, except that the amount of pentaerythritol distearate dry blended as a compounding additive was 1.9 parts by mass. The weight average molecular weight of the obtained pellets was 80,000, and the residual amount of pentaerythritol distearate was 1.7 wt%. Other properties are shown in the table.

[0087] Example 6 Pellets were obtained in the same manner as in Example 1, except that the amount of pentaerythritol distearate dry blended as a compounding additive was 2.7 parts by mass. The weight average molecular weight of the obtained pellets was 80,000, and the residual amount of pentaerythritol distearate was 2.5 wt%. Other properties are shown in the table.

[0088] Example 7 Pellets were obtained in the same manner as in Example 1, except that the amount of pentaerythritol tetrastearate dry blended as a compounding additive was 1.5 parts by mass. The weight average molecular weight of the obtained pellets was 88,000, and the residual amount of pentaerythritol tetrastearate was 1.3 wt%. Other properties are shown in the table.

[0089] Example 8 Pellets were obtained in the same manner as in Example 1, except that the amount of pentaerythritol distearate as compounding additives was 0.9 parts by mass and the amount of a dry blend of pentaerythritol tetrastearate was 0.5 parts by mass. The weight average molecular weight of the obtained pellets was 90,000, the residual amount of pentaerythritol distearate was 0.8 wt%, and the residual amount of pentaerythritol tetrastearate was 0.4 wt%. Other properties are shown in the table.

[0090] Example 9 Pellets were obtained in the same manner as in Example 2, except that underwater cutting was used when obtaining the pellets. The weight average molecular weight of the obtained pellets was 85,000, and the residual amount of pentaerythritol distearate was 1.3 wt%. Other properties are shown in the table.

[0091] (Comparative Example 1) Pellets were obtained in the same manner as in Example 1, except that the amount of pentaerythritol distearate dry blended as a compounding additive was 0.5 parts by mass. The weight-average molecular weight of the obtained pellets was 94,000, and the residual amount of pentaerythritol distearate was 0.3 wt%. Other properties are shown in the table.

[0092] (Comparative Example 2) Pellets were obtained in the same manner as in Example 1, except that the amount of pentaerythritol distearate dry blended as a compounding additive was 3.2 parts by mass. The weight average molecular weight of the obtained pellets was 85,000, and the residual amount of pentaerythritol distearate was 3.0 wt%. Other properties are shown in the table.

[0093] (Comparative Example 3) Pellets were obtained in the same manner as in Example 1, except that the amount of pentaerythritol distearate dry blended as a compounding additive was 3.2 parts by mass. The weight average molecular weight of the obtained pellets was 83,000, and the residual amount of pentaerythritol distearate was 3.0 wt%. Other properties are shown in the table.

[0094] Comparative Example 4 Pellets were obtained in the same manner as in Example 1, except that the amount of pentaerythritol distearate dry blended as a compounding additive was 4.2 parts by mass. The weight-average molecular weight of the obtained pellets was 79,000, and the residual amount of pentaerythritol distearate was 4.0 wt%. Other properties are shown in the table.

[0095] (Comparative Example 5) Pellets were obtained in the same manner as in Example 1, except that the amount of pentaerythritol monostearate dry blended as a compounding additive was 1.0 part by mass. The weight-average molecular weight of the obtained pellets was 85,000, and the residual amount of pentaerythritol monostearate was 0.8 wt%. Other properties are shown in the table.

[0096] (Comparative Example 6) Pellets were obtained in the same manner as in Example 1, except that the amount of a dry blend of a distilled product of diglycerin and oleic acid ester (Rikemal DO-100: manufactured by Riken Vitamin Co., Ltd.) used as a compounding additive was 1.0 part by mass. The weight-average molecular weight of the obtained pellets was 85,000, and the residual amount of diglycerin and oleic acid ester was 0.8 wt%. Other properties are shown in the table.

[0097] (Comparative Example 7) Pellets were obtained in the same manner as in Example 1, except that the amount of a dry blend of triglycerin and oleic acid ester (a mixture of monoester, diester, and triester; the mass ratio of the esters is shown in Table 2) was 1.0 part by mass as a compounding additive. The weight-average molecular weight of the obtained pellets was 85,000, and the residual amount of triglycerol diolate was 0.8 wt%. Other properties are shown in the table.

[0098] <Evaluation> The samples obtained in the above-mentioned Examples and Comparative Examples were evaluated as follows. (1) Measurement of the proportion of ring structures in a resin composition The proportion of ring structures in each sample of the cyclic olefin copolymer resin composition produced in the above-mentioned Production Examples and Production Comparative Examples was analyzed by the following procedure. First, 5.0 grams of the cyclic olefin resin composition was dissolved in 50 mL of cyclohexane, and then 300 mL of methanol was added to perform reprecipitation. The methanol-insoluble matter was separated by filtration. The solvent was evaporated, and the solid matter was separated. The solid matter was quantified so that the sample concentration was 5.0 wt / vol%, and 1.0 mL of o-dichlorobenzene-D4 was added. The sample was left to stand at room temperature for 16 hours or more to completely dissolve the sample. 13 C-NMR measurements were carried out. For quantification, the ratio of CH to CH was calculated from the ratio of the sum of the integral values ​​of all peaks observed in the range of 51.2 ppm to 36.8 ppm (k) to the sum of the integral values ​​of all peaks observed in the range of 36.8 ppm to 29.3 ppm (l). Using formula (I), it was confirmed that a predetermined amount of olefin and cyclotetracyclo[4.4.0.12,5.17,10]-3-dodecene were copolymerized in a molar ratio of n% olefin and ((100-n)%) cyclotetracyclo[4.4.0.12,5.17,10]-3-dodecene. n(%)=(4×l-2×k) / (4×lk)×100 (I) In addition, 13 The C-NMR measurement conditions are as follows: Measurement equipment: Bruker Biospin AVANCE3 500HD Prodigy Measurement solvent: o-dichlorobenzene-d4 ·Measurement temperature: 25℃ Observation frequency: 125MHz Pulse sequence: 13 C quantitative Accumulation count: 700 times Relaxation time: 10 seconds Sample concentration: 5.0wt / vol%

[0099] (2) Measurement of additive content The amount of additives in each sample of the cyclic olefin copolymer resin composition produced in the above Production Examples and Production Comparative Examples was analyzed by the following procedure. First, 5.0 g of the cyclic olefin resin composition was added to 50 mL of cyclohexane and stirred at 40°C for at least 1 hour to dissolve it. 200 mL of methanol was then added to perform a reprecipitation operation, and the methanol-soluble portion was separated. The solvent for the methanol-soluble portion was evaporated, and the dissolved component was concentrated and separated as a solid. The solid portion was weighed so that the sample concentration was 5.0 wt / vol%, and 1.0 mL of CDCl3 was added. The sample was left at room temperature for at least 30 minutes to completely dissolve the sample, and 1000 ppm of DMSO was added as an internal standard (weight is (w) mg). 1 H-NMR measurements were carried out. The integral value (ab) of the 6H component of DMSO alone was calculated by subtracting the integral value (b) of pentaerythritol tetrakis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate] (BASF Irganox 1010) observed at 2.79-2.88 ppm from the integral value (a) of DMSO at 2.56-2.65 ppm. The percentage content (x) of each compound was quantified using the following formula (II) based on the integral value (y) of the peak observed in the following chemical shift range, the molecular weight (M) of the additive, and the number of equivalent proton peaks (z). x(%)=(w / 78.1×y / (ab)×6 / z×M) / 5000×100 (II) In particular, for additives of higher fatty acid esters, the integral value of the peak derived from α-hydrogen in the higher fatty acid moiety observed at 2.0 to 2.5 ppm was quantified using formula (II) where y is the integral value, M is the molecular weight, and z is the number of hydrogen atoms derived from equivalent α-hydrogen. For additives corresponding to the examples, the integral range, M, and z are shown below. Pentaerythritol distearate Integral range: 2.27 ppm to 2.38 ppm M=669.09 z=4 Pentaerythritol tetrastearate Integral range: 2.27 ppm to 2.38 ppm M=1201.99 z=8 In addition,1 The H-NMR measurement conditions are as follows: Measurement equipment: Bruker Biospin AVANCE3 500HD Prodigy Measurement solvent: CDCl3 ·Measurement temperature: 25℃ Observation frequency: 500MHz Number of times accumulated: 128 Sample concentration: 5.0wt / vol%

[0100] (3) Measurement of glass transition temperature The glass transition temperature (Tg) (°C) of each sample prepared in the above Preparation Examples and Comparative Examples was measured in accordance with JIS-K7121. A differential scanning calorimeter (DSC8000, manufactured by Perkin-Lumer Japan Co., Ltd.) was used under conditions of a nitrogen gas 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 (first heating), held at 200°C for 5 minutes to completely melt, then cooled from 200°C to 40°C at a rate of 10°C / min, held at 40°C for 5 minutes, and heated again under the same heating conditions (second heating). The DSC curve obtained during this heating period was measured. The glass transition temperature (Tg) (°C) was determined as the intersection of the step-like change portion of the second heating curve with a straight line equidistant from each baseline extension.

[0101] (4) MFR For each sample produced in the above-mentioned Production Examples and Production Comparative Examples, the melt flow rate of the cyclic olefin copolymer resin composition was measured at a temperature of 260°C and a load of 2.16 kg using a melt indexer (manufactured by Toyo Seiki Seisakusho) under conditions in accordance with JIS K7210 Method A.

[0102] (5) Specific gravity of pellets For each sample produced in the above-mentioned Production Examples and Production Comparative Examples, the density of each pellet was measured using an electronic densimeter MDS-300 (manufactured by Alpha Mirage Co., Ltd.).

[0103] (6) Measurement of absolute value of photoelastic coefficient Each sample of the cyclic olefin copolymer resin composition produced in the above-mentioned Production Examples and Production Comparative Examples was pressed into a film using a vacuum compression molding machine to prepare a measurement sample. Specific sample preparation conditions were as follows: a vacuum compression molding machine (Shinto Metal Industries, SFV-30) was used to preheat the resin lens at 250°C under reduced pressure (approximately 10 kPa) for 10 minutes, and then the resin lens was cut out and compressed at 250°C and approximately 10 MPa for 5 minutes. After the vacuum and pressure were released, the film was transferred to a cooling compression molding machine and cooled to solidify. The resulting pressed film was aged for at least 24 hours in a constant temperature and humidity chamber adjusted to 23°C and 60% humidity, and then test specimens (approximately 150 μm thick and 6 mm wide) were cut out for measurement. The photoelastic coefficient CR (Pa −1 ) was measured using a birefringence measuring device described in detail in Polymer Engineering and Science 1999, 39, 2349-2357. The film-like test piece was placed on a film tensioning device similarly installed in a constant temperature and humidity chamber with a chuck distance of 80 mm. Next, a birefringence measuring device (Uniopto, ABR-100) was positioned so that the laser light path of the device was located at the center of the film, and the birefringence of the test piece was measured while applying a tensile stress at a strain rate of 0.1 mm / min. From the relationship between the measured birefringence (|Δn|) and the tensile stress (σR), the slope of the line was calculated by least squares approximation, and the photoelastic coefficient (CR) (Pa -1 ) was calculated using data for the tensile stress range of 0N≦σR≦20N. CR=|Δn| / σR Here, the birefringence (Δn) has the following value. |Δn|=|nx-ny| (nx: refractive index in the stretching direction, ny: refractive index in the in-plane direction perpendicular to the stretching direction)

[0104] (7) Storage modulus at high temperatures The pellets of each sample produced in the above-mentioned Production Examples and Production Comparative Examples were dried at 80 to 100°C for 24 hours and injection-molded using an injection molding machine (manufactured by The Japan Steel Works, Ltd., J100ADS-110U) in accordance with JIS-K7152-1 to produce 4.0 mm thick ISO 3167 A-type dumbbell test specimens. The molding temperature was set at 250°C. The 4 mm thick (ISO 3167 A-type dumbbell test specimens) were annealed at 99°C for 16 hours and then left to stand in an environment of 23°C and 50% humidity for at least 24 hours to condition them. The storage modulus of the ISO dumbbell test specimens was measured using the following equipment and under the following measurement conditions. Measuring device: EPLEXOR 500N (GABO) Measurement mode: Tensile / Temperature sweep Atmosphere: Nitrogen Static strain-load limit: 0.4%-100N (error 0.035%) Dynamic strain-load limit: 0.2%-80N (error 0.015%) Contact load: 1N Measurement temperature: 0~200℃ Heating rate: 3°C / min Frequency: 1Hz Sample shape: ISO3167 A-type dumbbell test piece Measurement gap: 30 mm

[0105] (8) Measurement of bending strength and bending modulus Pellets of the resin composition prepared in the above-described Production Example were dried at 80 to 100°C for 24 hours and injection-molded using an injection molding machine (manufactured by The Japan Steel Works, Ltd., J100ADS-110U) according to JIS-K7152-1 to prepare 4.0 mm thick ISO 3167 A-type dumbbell test specimens. The molding temperature was set at 250°C. The center of this test specimen was cut out to prepare a molded specimen measuring 80 mm in length, 10 mm in width, and 4.0 mm in thickness. A bending test was performed according to ISO 178 using a low-load universal testing machine (manufactured by Instron) at a measurement temperature of 23°C, a test speed of 2 mm / min, and a support distance of 64 mm. Six measurements were performed, and the flexural strength (MPa) and flexural modulus (MPa) were calculated as the average values.

[0106] (9) Evaluation of black foreign matter in molded products The above-mentioned A-type dumbbell test pieces were observed under a microscope to evaluate the presence or absence of burnt foreign matter. They were classified according to the following criteria. Good: Few burnt foreign objects. ×: There are many burnt foreign matters.

[0107] (10) Molding a φ45mm biconvex lens by injection molding Each sample of the cyclic olefin copolymer resin composition obtained in the Examples and Comparative Examples was injection molded using an injection molding machine (FANUC, S-2000i50B). A plano-convex lens with an optical axis thickness of 7.0 mm and a diameter of 45 mm was used for the mold. The first surface, which includes the optical axis, was convex, with an aspherical shape having a radius of curvature of R95 mm, a conic constant k of -1.12452, and no even-order constants. The second surface, which includes the optical axis, was convex, with a radius of curvature of R68 mm. (When the second surface is viewed as positive, it is expressed as a spherical surface with a radius of curvature R = -68 mm.) The effective diameter of the lens was 41 mm, and a 2 mm-wide protruding flange was provided on the outer periphery of the lens surface, resulting in an overall diameter of 45 mm. Molding was performed with a cylinder temperature set at Tg + 120 to Tg + 130°C of the resin composition used, and a mold temperature set at Tg to Tg - 15°C of the resin composition used. The holding pressure was set at 90 to 100 MPa for 6 seconds in the first stage, and then at 80 MPa for 3 seconds from the second stage onwards to alleviate stress distortion inside the molded product. Molding was performed with an injection speed set at 10 to 20 mm / s, resulting in a φ45 mm biconvex lens. The lens shape was measured using an NH-3SPs (manufactured by Mitaka Kohki Co., Ltd.), and the molding conditions were adjusted appropriately to obtain a lens of the desired shape.

[0108] (11) Phase difference within the effective diameter of the resin lens The φ45 mm biconvex lens prepared in (10) above was measured for the surface distribution of the phase difference of the lens from the optical axis direction at a wavelength of 520 nm using a birefringence evaluation system PA-300-L manufactured by Photonic Lattice, and the average value (nm) of the absolute value of the phase difference was calculated by specifying an area within the effective diameter (φ41 mm) of the lens. The average value of three lenses was used as the measured value. For the lenses made from the samples of the Examples and Comparative Examples, the value of the phase difference within the effective diameter of the lens measured using the lens after molding was taken as the initial Re. The lens was then heat-treated at the first heat treatment step temperature specified in the annealing step described in JP 2020-185742 A, and the phase difference within the lens effective diameter was measured using the quenched lens, and the measured value was the single-stage annealing Re. Furthermore, according to the annealing step described in JP 2020-185742 A, the lens was heat-treated at the first heat treatment step temperature, gradually cooled to 90°C over 50 minutes, and annealed at 90°C for 1 hour. The phase difference within the lens effective diameter was measured using the lens, and the measured value was the two-stage annealing Re.

[0109] (12) Observation of the appearance of resin lenses The appearance of the resin lenses obtained in the examples and comparative examples was observed and judged according to the following criteria. 〇: Highly transparent molded product with no white haze (cloudiness) △: Slight cloudiness is observed. ×: Cloudiness is observed, and streaky white haze is visible.

[0110] (13) Molding a φ41mm plano-convex lens by injection molding Each sample of the cyclic olefin copolymer resin composition obtained in the Examples and Comparative Examples was injection molded using an injection molding machine (FANUC, S-2000i50B). A plano-convex lens with an optical axis thickness of 3.2 mm and a diameter of 41 mm was used for the mold. The resulting aspheric shape had a convex surface with a radius of curvature of R95.077 mm on the surface including the optical axis, and the conic constant k was set to -1.465, with even-order aspheric constants D=2.169E-07, E=-2.106E-10, and F=-1.796E-13. Molding was performed with a cylinder temperature set to Tg + 120 to Tg + 135°C of the resin composition used and a mold temperature set to Tg - 15°C of the resin composition used. The first-stage holding pressure was 60 MPa for 4 seconds, followed by a second-stage holding pressure of 40 MPa for 3 seconds to alleviate stress distortion within the molded product. Molding was performed at an injection speed of 10 mm / s to obtain a φ41 mm plano-convex lens. The lens shape was measured using an NH-3SPs (manufactured by Mitaka Kohki Co., Ltd.), and molding conditions were adjusted appropriately to obtain a lens of the desired shape. The resulting lens was then annealed under the conditions specified for the annealing process described in JP 2020-185742 A. The lens was then ultrasonically cleaned using a cleaning solution containing water and a surfactant, then vacuum dried at 80°C for 6 hours, after which an anti-reflection coating was applied to the flat surface by vapor deposition.

[0111] (14) Contrast when used with a pancake lens For the φ45mm biconvex lens manufactured in (10) above, a lens was prepared by bonding a wire grid polarizer to the convex surface, with reference to the contents of JP 2024-4491 A, and the contrast in a pancake lens configuration was evaluated using this lens. A simulation device was created in a darkroom to simulate the principle of the head-mounted display with a pancake lens configuration shown in Figure 2. The optical data used as the basis for creating the device is shown in Table 1. The Type column in Table 1 indicates the surface shape, d is the refractive index of the d line, ν d is the Abbe number based on the d-line, and thickness is the distance between each surface. In the type column, SPH means that the surface shape is spherical, and ASP means that the surface shape is aspherical. The radius of curvature R, conic constant k, and even-order aspherical coefficients D, E, F, and G that represent the surface shape are expressed using the aspherical calculation formula in Equation 1. An infinity radius of curvature means a flat surface. The surface number is calculated by tracing the backward ray from the virtual image position to the image display element surface, with the exit pupil position being surface 1. In the simulated device, a smartphone 30 (AQUOS sense6, SH-M19 manufactured by Sharp Corporation) was placed and an image was output. The image displayed was a grid pattern of black ■s surrounded by white lines, as shown in Figure 4. The display was set up so that the diameter of the circumscribing circle of the area consisting of the nine black ■s and the white lines surrounding them matched the effective diameter of the image display area, or the diameter of the circumscribing circle was more than 90% of the effective diameter of the image display area. The image light then passes through a circular polarization element 33 (a combination of an absorption-type linear polarization element and a quarter-wave plate, manufactured by Kenko Tokina Co., Ltd., 49S ZX C-PL) with the linear polarization element facing the smartphone 30, where it is converted into circularly polarized light (e.g., counterclockwise circular polarization when viewed from the direction of travel). The image light then passes through a half-mirror element 34 (the entrance surface is anti-reflection coated, and the exit surface is a dielectric multilayer half mirror, with a transmittance:reflectance = 50%:50%). The image light then passes through a quarter-wave plate 35 (a Nippon Kayaku Co., Ltd. element consisting of a 40 mm diameter WA140T sandwiched between two 0.7 mm thick glass plates with AR coating on one side, with the AR coating facing outward), where it is converted into linearly polarized light (first linearly polarized light). Whether the combination of the circular polarization element 33 and quarter-wave plate 35 results in linear polarization can be confirmed separately, and whether light can be blocked using a linear polarization element can be confirmed. Further, a light shielding portion 39 is provided outside the quarter-wave plate 35 to shield unnecessary light such as stray light due to reflection. Next, the reflective polarizing element bonded lens 36 is positioned so that image light is incident from the resin lens side 361, and is bonded and fixed to the lens barrel. At this time, the axis of the incident linearly polarized light is set to coincide with the reflection axis of the reflective polarizing element 362, so that after passing through the resin lens, the light is reflected by the reflective polarizing element 362 and the optical path is folded back. The light again passes through the resin lens 361 and the quarter-wave plate 35, where it is converted into circularly polarized light (e.g., left-handed circularly polarized light as viewed from the direction of travel), and is then reflected by the half mirror element 34, where it is converted into circularly polarized light (e.g., right-handed circularly polarized light as viewed from the direction of travel). After passing through the quarter-wave plate 35, it is converted into second linearly polarized light whose axis is rotated 90 degrees from the first linearly polarized light, which passes through the resin lens 361, and then passes through the reflective polarizing element 362 because the polarization coincides with the transmission axis. Furthermore, the polarizing element side surface of the circular polarizing element 37 is positioned toward the reflective polarizing element bonded lens 362 so that the second linearly polarized light is transmitted. The images were taken using a Canon EOS RP digital single-lens camera 38 (with a standard zoom lens RF24-105mm F4-F7.1 IS STM). If the image was out of focus, the position of the smartphone 30 was adjusted within a range of 1 to 3 mm. The shooting conditions were ISO 8000, focal length 31 mm, exposure time 1 / 250 second, and aperture value f / 5.6. For an image with a black square in the center, the contrast was calculated by inputting the luminance of the black square and the luminance of the adjacent white lines into Equation 4. The contrast values ​​between the nine black squares and the adjacent white lines were averaged to determine the image contrast for the evaluation of the present invention. The luminance value of the image was also calculated using ImageJ. As shown in Figure 3, when a reflective polarizing element-bonded lens with large birefringence is used, ghosts and flares occur, reducing contrast. Equation 4: Image contrast = (average brightness of the white line adjacent to the black ■ - average brightness of the black ■) / (average brightness of the white line adjacent to the black ■ + average brightness of the black ■)

[0112] [Table 1]

[0113] (15) How the image appears when the display is overheating The experimental device with the pancake lens configuration prepared in (14) above was left in an oven at 110°C for 15 minutes, and then removed and immediately thereafter visually evaluated for the image quality. The evaluation was based on the following criteria: 〇: There is no difference in the image when viewed at room temperature. △: A slight decrease in image contrast was observed compared to images viewed at room temperature. ×: A decrease in contrast was observed compared to the image viewed at room temperature.

[0114] (16) Appearance evaluation after thermal cycle test Ten reflective polarizing element-bonded lenses used in the pancake lens configuration prepared in (14) above were subjected to a thermal cycle test in a thermo-hygrostat (Espec Corporation's low-temperature thermo-hygrostat PL-2J), with 20 cycles of one cycle at -30°C for one hour and one at 60°C for one hour. The appearance of the reflective polarizing element-bonded lenses was evaluated according to the following criteria, and the number of defective lenses was counted. The measurement results are shown in Table 2. The number of defective lenses measured can be evaluated according to the following criteria. Good: Good appearance with no wrinkles, bubbles, peeling, etc. Defective: Cracks in the lens or wrinkles, bubbles, or peeling in the reflective return element are found.

[0115] [Table 2]

[0116] As described above, the molded articles (lenses) made from the cyclic olefin copolymer resin compositions obtained in Examples 1 to 8 exhibited low birefringence after two-stage annealing and an excellent balance of performance in terms of appearance defects, mold contamination, and surface precision. Furthermore, even when used as a VR lens with a pancake lens configuration, ghosts and flare due to birefringence were observed near the gate of the molded lens, but good contrast was observed in the observed image. In Example 9, pellets were obtained using an underwater cut during pelletizing, which tended to increase the number of burnt foreign matter, but other properties were as excellent as in the other Examples. On the other hand, Comparative Example 1, which contained only 0.3% by mass of higher fatty acid ester, did not reduce birefringence, and Comparative Example 2, which contained 3.0% by mass of higher fatty acid ester, showed a reduction in birefringence, but was inferior in performance to the Examples in terms of poor appearance, mold fouling, and surface precision. Comparative Example 3, which used a resin with a low Tg and contained 1.5% by mass of higher fatty acid ester, was inferior in performance in terms of PV value after annealing and image visibility during heat generation. Comparative Example 4, which used a resin with a high Tg and contained 4.0% by mass of higher fatty acid ester, was inferior in performance in terms of poor appearance and image visibility during heat generation. Furthermore, Comparative Examples 5 to 7, which used higher fatty acids with three or more hydroxy groups, were also inferior in performance to the Examples in terms of poor appearance, mold fouling, and surface precision.

Claims

1. A resin composition comprising a cyclic olefin copolymer, which is a copolymer of ethylene or an α-olefin and a cyclic olefin, The absolute value of the photoelastic coefficient measured at 110°C is 10.0 x 10 －１２ Pa －１ is as follows: The glass transition temperature is 130°C or higher, The cyclic olefin copolymer resin composition further comprises 0.5 to 2.8 mass % of a higher fatty acid ester.

2. 2. The cyclic olefin copolymer resin composition according to claim 1, wherein the higher fatty acid ester has two or less hydroxy groups in the molecule.

3. 3. The cyclic olefin copolymer resin composition according to claim 1, wherein the polyhydric alcohol constituting the higher fatty acid ester is pentaerythritol distearate.

4. 3. The cyclic olefin copolymer resin composition according to claim 1, wherein the proportion of ring skeleton constituent units in the main chain of the cyclic olefin copolymer is 36 mol % or more and 50 mol % or less.

5. The repeating units derived from the cyclic olefin in the cyclic olefin copolymer are bicyclo[2.2.1]-2-heptene and tetracyclo[4.4.0.1]-heptene. 2,5 .1 7,10 3. The cyclic olefin copolymer resin composition according to claim 1, wherein the repeating units are derived from at least one compound selected from the group consisting of cycloolefin copolymers, ...

6. 3. The cyclic olefin copolymer resin composition according to claim 1, wherein the weight average molecular weight Mw is 70,000 to 100,000.

7. 3. The cyclic olefin copolymer resin composition according to claim 1, wherein the flexural strength is 70 MPa or more.

8. 3. The cyclic olefin copolymer resin composition according to claim 1, wherein the flexural strength is 80 MPa or more.

9. The specific gravity of the pellets made of the cyclic olefin copolymer resin composition is 1.0 g / cm ３ The cyclic olefin copolymer resin composition according to claim 1 or 2, characterized in that

10. A lens comprising the cyclic olefin copolymer resin composition according to claim 1 or 2, and used in an ocular optical system.

11. A waveguide comprising the cyclic olefin copolymer resin composition according to claim 1 or 2, and having a thickness of 1.0 mm or less.

12. A prism comprising the cyclic olefin copolymer resin composition according to claim 1 or 2.

Images