Resin composition, optical element, optical apparatus, image pickup apparatus, and method for manufacturing optical element

Abstract

To provide a resin composition having small birefringence and being less likely to exhibit changes in optical performance even under a high humidity environment, even in a cured product after curing.SOLUTION: A resin composition of the present invention has a first monomer containing a polymerizable functional group of a difunctional (meth)acrylate having a fluorene skeleton, and at least one of a second monomer containing a polymerizable functional group of a monofunctional (meth)acrylate having an alicyclic skeleton, a polymer of the second monomer, and a third monomer containing a polymerizable functional group of a difunctional (meth)acrylate having an alicyclic skeleton. The total content of the first monomer, the second monomer, the polymer of the second monomer, and the third monomer is in a range of 70 mass% or more and 99.5 mass% or less.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present disclosure relates to a resin composition, an optical element, an optical device, an imaging device, and a method for manufacturing an optical element.

Background Art

[0002] As one of optical elements, a lens in which a cured product of a resin composition is provided on a transparent substrate such as glass is known. Such a lens is manufactured by using a mold, providing a resin composition between the substrate and the mold, and polymerizing or copolymerizing to form a cured product having a desired shape on the surface of the substrate. A lens manufactured by such a manufacturing method is called a replica element. Since the replica element can easily form a desired surface shape, it is effective for use as an aspherical lens or a Fresnel lens. An aspherical lens is a general term for lenses in which the curvature continuously changes from the center to the periphery of the lens. Patent Documents 1 and 2 disclose resin compositions that can be used for replica elements.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, since the cured product of the resin composition disclosed in Patent Document 1 has a high water absorption expansion rate, for example, there is a problem that the optical performance is likely to change in a high-humidity environment. In addition, the cured product of the resin composition disclosed in Patent Document 2 may have a large birefringence depending on the desired optical characteristics.

Means for Solving the Problems

[0005] To solve the above problems, the resin composition has a first monomer having a polymerizable functional group of a bifunctional (meth)acrylate having a fluorene skeleton represented by the following general formula (1), a second monomer having a polymerizable functional group of a monofunctional (meth)acrylate having an alicyclic skeleton represented by any one of the following general formulas (2) to (5), a polymer of the second monomer, and at least one of a third monomer having a polymerizable functional group of a bifunctional (meth)acrylate having an alicyclic skeleton represented by any one of the following general formulas (2) to (5), and the sum of the contents of the first monomer, the second monomer, the polymer of the second monomer, and the third monomer is in the range of 70% by mass or more and 99.5% by mass or less.

[0006]

Chemical formula

[0007] (In general formula (1), at least one of R 11 ~R 19 has a polymerizable functional group of (meth)acrylate, and the others are hydrogen atoms or organic groups.)

[0008]

Chemical formula

[0009]

Chemical formula

[0010]

Chemical formula

[0011]

Chemical formula

[0012] (In general formula (5), R is a hydrogen atom, an alkyl group, or a substituted or unsubstituted alkylene group.) [Advantages of the Invention]

[0013] According to the above aspect, it is possible to provide a resin composition that is less likely to change in optical performance even in a cured product after curing and even in a high-humidity environment, and has low birefringence. [Brief Description of the Drawings]

[0014]

Figure 1

Figure 2

Figure 3

Figure 4

[0015] Hereinafter, embodiments of the present disclosure will be described.

[0016] [Optical Element] FIG. 1 is a schematic diagram showing an optical element according to the first embodiment, and is a side cross-sectional view of the optical element 10 cut in the stacking direction by a straight line passing through the element center O of the optical element.

[0017] The optical element 10 has a transparent substrate 1 and a cured product 2. The optical element 10 is an optical element of a type called a replica lens in which a cured product is provided on the transparent substrate 1.

[0018] (Transparent Substrate) The transparent substrate 1 has a first surface 1A and a second surface 1B that are optical surfaces. The first surface 1A of the transparent substrate is one of the light incident surface or the light emitting surface, and the second surface 1B of the transparent substrate is the other of the light incident surface or the light emitting surface.

[0019] As the transparent substrate 1, a transparent resin or a transparent glass can be used. In this specification, "transparent" means that the transmittance of light in the wavelength range of 400 nm or more and 780 nm or less is 10% or more. It is preferable to use glass as the transparent substrate 1. For example, general optical glasses typified by silicate glass, borosilicate glass, and phosphate glass, quartz glass, and glass ceramics can be used.

[0020] In FIG. 1, the first surface 1A is concave spherical, and the second surface 1B is convex spherical, but the shape of the transparent substrate 1 is not particularly limited. The shape of the surface of the transparent substrate 1 that contacts the cured product 2 can be selected according to desired characteristics from a concave spherical surface, a convex spherical surface, an axially symmetric aspherical surface, a flat surface, etc. The transparent substrate 1 is preferably circular when viewed from above in the plane of FIG. 1. This is because the assembly accuracy is improved when the optical element 10 is used in an optical system described later as a lens.

[0021] (Cured product) The cured product 2 is provided in close contact with the first surface 1A of the transparent substrate. The cured product 2 is a cured product of a resin composition obtained by polymerizing or copolymerizing the resin composition 2a.

[0022] The resin composition 2a preferably has a first material, a second material, and a polymerization initiator.

[0023] The first material is a first monomer having a polymerizable functional group of a bifunctional (meth)acrylate having a fluorene skeleton represented by the general formula (1).

[0024] [Chemical formula]

[0025] Here, in the general formula (1), R 11 ~R 20At least two of them have polymerizable functional groups of (meth)acrylate, and the others are hydrogen atoms or organic groups. The organic group may have other polymerizable functional groups. The other polymerizable functional groups are, for example, vinyl groups and epoxy groups. In other words, R 11 ~R 20 may have an organic group having a vinyl group, an organic group having an epoxy group, etc.

[0026] The component of the polymer of the first monomer plays a role of increasing the refractive index and decreasing the water absorption expansion rate in the cured product 2. However, usually, the birefringence tends to increase.

[0027] The first monomer preferably has a fluorene skeleton represented by the general formula (6). The fluorene skeleton represented by this general formula (6) plays a role of showing a particularly high refractive index nd.

[0028]

Chemical formula

[0029] In the general formula (6), R1 and R3 are

[0030]

Chemical formula

[0031] any one of them, and R2 and R4 are any one of a hydrogen atom, CH2, and an alkyl group.)

[0032] The second material includes at least one of a second monomer having a polymerizable functional group of a monofunctional (meth)acrylate having an alicyclic skeleton represented by any of the following general formulas (2) to (5), a polymer of the second monomer, and a third monomer having a polymerizable functional group of a bifunctional (meth)acrylate having an alicyclic skeleton represented by any of the following general formulas (2) to (5).

[0033]

Chemical formula

[0034]

Chem.

[0035]

Chem.

[0036]

Chem.

[0037] In general formula (5), R is a hydrogen atom, an alkyl group, or a substituted or unsubstituted alkylene group.

[0038] The alicyclic skeleton represented by general formula (2) is a tricyclodecane skeleton. The alicyclic skeleton represented by general formula (3) is an isobornyl skeleton. The alicyclic skeleton represented by general formula (4) is a dicyclopentenyl skeleton. The alicyclic skeleton represented by general formula (5) is an adamantane skeleton. A polymer obtained by polymerizing monomers having a tricyclodecane skeleton, an isobornyl skeleton, a dicyclopentenyl skeleton, and an adamantane skeleton functions to lower the water absorption expansion rate in cured product 2. Also, due to the alicyclic structure having its three-dimensional structure, it functions to suppress a decrease in birefringence caused by the first material.

[0039] The resin composition 2a of the present disclosure may further have a third monomer having a polymerizable functional group of a bifunctional (meth)acrylate having an alicyclic skeleton represented by the above general formulas (2) to (5).

[0040] In the resin composition 2a of the present disclosure, the sum of the contents of the first material and the second material is in the range of 70% by mass or more and 99.5% by mass or less. By setting the composition ratio of the resin composition 2a of the present disclosure as described above, when it is cured to form a cured product, it has a low water absorption expansion rate and excellent adhesion to a transparent substrate. When the sum of the above contents exceeds 99.5% by mass, the content of the polymerization initiator becomes relatively small, curing becomes difficult, the transfer accuracy of the cured product 2 becomes insufficient, and the optical performance tends to fluctuate. On the other hand, when it is less than 70% by mass, the water absorption expansion rate of the cured product 2 becomes high, and for example, in a high-humidity environment where the humidity is 80% or more, the optical performance tends to change easily.

[0041] Preferably, the resin composition 2a of the present disclosure has a content of the first monomer in the range of 10% by mass or more and 30% by mass or less. When it is in this range, it becomes easy to reduce birefringence and increase the refractive index nd of the d-line to 1.54 or more. When it is less than 10% by mass, it may be difficult to increase the refractive index nd of the d-line of the cured product 2 depending on the composition ratio. On the other hand, when it exceeds 30% by mass, the birefringence of the cured product 2 may increase depending on the composition ratio.

[0042] Further, preferably, in the resin composition 2a of the present disclosure, the sum of the contents of the second monomer, its polymer, and the third monomer is in the range of 40% by mass or more and 85.9% by mass or less. When it is in this range, it becomes easy to reduce birefringence and increase the refractive index nd of the d-line to 1.54 or more. When it is less than 40% by mass, the birefringence of the cured product 2 may increase depending on the composition ratio. On the other hand, when it exceeds 85.9% by mass, it may be difficult to increase the refractive index nd of the d-line of the cured product 2.

[0043] The resin composition 2a contains a polymerization initiator. The polymerization initiator may be a photoinitiator or a thermal polymerization initiator, and can be determined according to the manufacturing process selected. However, when performing replica molding for manufacturing an aspherical shape, from the viewpoint of a high curing rate, it is preferably a photoinitiator. Examples of commercially available photoinitiators include 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)-1-butanone, 1-hydroxycyclohexyl phenyl ketone, bis(2,4,6-trimethylbenzoyl)-phenylphosphine oxide, 4-phenylbenzophenone, 4-phenoxybenzophenone, 4,4'-diphenylbenzophenone, and 4,4'-diphenoxybenzophenone. The content of the photoinitiator in the resin composition 2a is preferably in the range of 0.01% by mass or more and 10% by mass or less. If the content of the photoinitiator is less than 0.01% by mass, sufficient reactivity cannot be obtained, and if it exceeds 10% by mass, the transmittance of the cured product 2 may decrease. Note that unreacted polymerization initiator remains in the cured product 2.

[0044] Also, the resin composition 2a may be added with a polymerization inhibitor, an antioxidant, a light stabilizer (HALS), an ultraviolet absorber, a silane coupling agent, a release agent, a pigment, a dye, etc., as necessary.

[0045] The cured product 2 preferably has a small birefringence, specifically, preferably within ±0.0004. The birefringence of the cured product 2 refers to the refractive index n of the S-polarization (in-plane direction of the incident plane) of the refractive index nd of the d-line (587.6 nm) d S and the refractive index n of the P-polarization (thickness direction) d pIt is the difference. The incident surface is the surface facing the first surface 1A of the transparent substrate. Further, the refractive index nd of the cured product 2 for the d-line (587.6 nm) is preferably 1.54 or more and 1.58 or less. When the refractive index is increased, the aspherical effect of the cured product, which is in a correlation with the product of the refractive index and the thickness, can be enhanced. When the cured product disclosed in Patent Document 2 is formed on a transparent substrate with the refractive index nd of 1.54 or more, birefringence may become large. However, according to the cured product 2 of the present disclosure, it is possible to provide a resin composition with small birefringence and difficult to change optical performance even in a high-humidity environment.

[0046] The cured product 2 preferably has high transparency. Specifically, the internal transmittance at a wavelength of 400 nm in terms of a thickness of 500 μm is preferably 70% or more.

[0047] Further, the Abbe number of the cured product 2 is preferably 30 or more and less than 45. If it is within these ranges, when the optical element 10 is used as a lens in an optical system, it is possible to cope with various optical designs.

[0048] In FIG. 1, the thickness of the cured product 2 is not uniform in the plane of the first surface 1A. That is, the shape of the surface of the cured product 2 on the side not in contact with the transparent substrate 1 is aspherical. In the present embodiment, it has a thickness distribution that is thin near the center O of the element and becomes the minimum thickness d1, and becomes the maximum thickness d2 at the peripheral portion of the element, but it does not necessarily have to be this shape. For example, it may have a thickness distribution such that the maximum thickness d2 is obtained near the center O of the element and the minimum thickness d1 is obtained at the peripheral portion of the element. The ratio of the maximum thickness d2 to the minimum thickness d1 of the cured product 2 is preferably greater than 1 and in the range of 30 or less. If it is greater than 30, since the difference in the thickness of the cured product 2 is large, there is a possibility that the surface accuracy cannot be maintained at a high level during curing shrinkage. More preferably, it is 8 or more. Note that the minimum thickness d1 is preferably 300 μm or less, and the maximum thickness d2 is preferably in the range of 10 μm or more and 1000 μm or less.

[0049] Further, the water absorption expansion rate of the cured product 2 provided on the transparent substrate 1 is preferably less than 0.30%. This is because fluctuations in optical properties due to water absorption expansion can be reduced. If the water absorption expansion rate is 0.30% or more, the change in the surface shape of the cured product 2 before and after water absorption is large, which may affect the image quality when used in an optical system. Therefore, it is preferably less than 0.20%, and more preferably 0.15% or less. The water absorption expansion rate is evaluated by a shape measuring instrument for the surface shape of the cured product 2 20 minutes after taking out the optical element 10 and placing it in a thermo-hygrostat at a temperature of 40°C and a humidity of 90% for 16 hours and then taking it out to a room temperature environment (23°C ± 2°C).

[0050] In addition, in this embodiment, the optical element 10 had an aspect having the transparent substrate 1, but depending on the optical properties of the optical element 10, it may not have the transparent substrate 1.

[0051] [Manufacturing method of optical element] The manufacturing method of the optical element of the above-described embodiment is not particularly limited, but an example of a suitable manufacturing process will be described. FIG. 2 is a schematic diagram showing the manufacturing method of the optical element according to the above-described embodiment.

[0052] First, the transparent substrate 1 and the resin composition 2a are prepared (preparation step). In order to improve the adhesion between the transparent substrate 1 and the cured product 2, it is preferable to perform a pretreatment on the first surface 1A of the transparent substrate. If the transparent substrate 1 is glass, for example, silane coupling treatment, corona discharge treatment, UV ozone treatment, or plasma treatment can be selected. From the viewpoint of being able to further enhance the adhesion by directly chemically bonding the first surface 1A and the cured product 2, it is preferable to perform coupling treatment using a silane coupling agent. Specific coupling agents include, for example, hexamethyldisilazane, methyltrimethoxysilane, trimethylchlorosilane, and triethylchlorosilane.

[0053] The method for obtaining the resin composition 2a is not particularly limited. The means and time for mixing are not particularly limited, and it is preferable to mix so as to be uniform.

[0054] Subsequently, as shown in Fig. 2(a), the resin composition 2a is dropped onto the mold 4. The resin composition 2a is an ultraviolet-curable composition containing a photoinitiator. The transparent substrate 1 is placed on the ejector 5 and arranged at a position facing the mold 4. The mold 4 has, for example, an inverted shape of a desired aspherical shape on its surface, and can be produced by cutting a NiP-plated or electroless copper-plated metal base material such as stainless steel or steel with a precision machining machine. Further, a release agent may be applied to the surface of the mold 4 to control the release property of the resin. The type of the release agent is not particularly limited, and for example, there is a fluorine coating agent.

[0055] Subsequently, as shown in Fig. 2(b), the ejector 5 is lowered so that the mold 4 approaches the transparent substrate 1, whereby the resin composition 2a is provided on the transparent substrate 1 (installation step). The ejector 5 is further lowered so that the space between the mold 4 and the transparent substrate 1 is filled with the uncured resin composition 2a and formed into a desired shape (forming step).

[0056] Then, by irradiating ultraviolet rays from the second surface 1B side of the transparent substrate 1 using the ultraviolet light source 6, a cured product 2 which is a polymerized and cured product of the resin composition 2a is obtained (curing step, light irradiation step).

[0057] Thereafter, by releasing the polymerized and cured cured product 2 from the mold 4, an optical element 10 having an aspherical cured product 2 on the transparent substrate 1 is obtained. After the cured product 2 is formed, additional irradiation with ultraviolet rays or heat treatment may be performed in the air or in an oxygen-free atmosphere.

[0058] By the above manufacturing method, the optical element of the first embodiment can be manufactured. In the installation step, the resin composition 2a may be dropped onto both the mold 4 and the transparent substrate 1, or may be dropped only onto the transparent substrate 1. Further, when the resin composition 2a contains a thermal polymerization initiator as a curing initiator, the light irradiation step may be changed to a heat treatment step. Further, after the curing step, the transparent substrate 1 may be peeled off from the optical element 10, and only the cured product 2 may be used as the optical element 10.

[0059] [Optical instrument] Specific application examples of the optical element of the above-described embodiment include lenses that constitute optical devices (imaging optical systems) for cameras and video cameras, and lenses that constitute optical devices (projection optical systems) for liquid crystal projectors. Further, it can also be used for pickup lenses such as DVD recorders. These optical systems are composed of at least one lens disposed in a housing, and the above optical element can be used for at least one of those lenses.

[0060] [Imaging device] FIG. 3 is a schematic diagram showing the configuration of a single-lens reflex digital camera 600, which is an example of a preferred embodiment of an imaging device using the optical element of the above-described embodiment. In FIG. 3, a camera body 602 and a lens barrel 601 as an optical device are coupled, and the lens barrel 601 is a so-called interchangeable lens that is detachable from the camera body 602.

[0061] Light from a subject is photographed through an optical system composed of a plurality of lenses 603, 605, etc. disposed on the optical axis of the imaging optical system within the housing 620 of the lens barrel 601. The optical element of the first embodiment can be used, for example, for the lenses 603, 605. Here, the lens 605 is supported by an inner cylinder 604 and is movably supported with respect to the outer cylinder of the lens barrel 601 for focusing and zooming.

[0062] During the observation period before shooting, the light from the subject is reflected by the main mirror 607 inside the housing 621 of the camera body, passes through the prism 611, and then the photographed image is projected onto the photographer through the viewfinder lens 612. The main mirror 607 is, for example, a half mirror, and the light transmitted through the main mirror is reflected by the sub-mirror 608 in the direction of the AF (auto focus) unit 613. For example, this reflected light is used for distance measurement. Also, the main mirror 607 is mounted and supported on the main mirror holder 640 by adhesion or the like. During shooting, the main mirror 607 and the sub-mirror 608 are moved out of the optical path via a drive mechanism (not shown), the shutter 609 is opened, and the imaging element 610 receives the light that has entered from the lens barrel 601 and passed through the imaging optical system to form a photographed optical image. Further, the aperture 606 is configured to be able to change the brightness and depth of focus during shooting by changing the aperture area.

[0063] Here, although the imaging device has been described using a single-lens reflex digital camera, it can be similarly used for smartphones, compact digital cameras, drones, etc.

Example

[0064] Hereinafter, the description will be given with reference to examples and comparative examples. First, the evaluation methods of the examples and comparative examples will be described.

[0065] (Water absorption test) The water absorption expansion rate of the cured product of the optical element in the examples and comparative examples was evaluated using an optical element provided with the cured product on a transparent substrate.

[0066] First, the fabricated optical element was placed in a thermo-hygrostat at a temperature of 40 °C and a humidity of 90% for 16 hours. Subsequently, the optical element was taken out in a room temperature environment (23 °C ± 2 °C), and after 20 minutes, the surface shape of the cured product was evaluated using a shape measuring machine (Form Talysurf Laser, manufactured by TAYLOR HOBSON). The measurement was performed by linearly scanning the light from one end of the optical element through the center to the opposite end at a scanning speed of 0.5 mm / sec. The water absorption expansion rate [%] of the optical element was calculated using the following formula from the average thickness D0 before water absorption and the average thickness D1 after water absorption. Water absorption expansion ratio [%] = ((D1 - D0) / D0) × 100

[0067] The evaluation was conducted as follows. A: Those with no peeling of the cured product and a water absorption expansion ratio of less than 0.20% B: Those with no peeling of the cured product and a water absorption expansion ratio of less than 0.30% C: Those with peeling of the cured product or a water absorption expansion ratio of 0.30% or more

[0068] (Refractive index nd of the d-line, Abbe number νd, birefringence) For the refractive index nd, Abbe number νd, and birefringence of the cured products of the optical elements in the examples and comparative examples, samples for optical property evaluation were prepared and evaluated. Note that it is also possible to evaluate by peeling the transparent substrate from the optical element and taking out the cured product without using the samples for optical property evaluation. First, the method for preparing the samples for optical property evaluation will be described.

[0069] A spacer with a thickness of 500 μm and an uncured resin composition, which is a precursor of the cured product to be measured, were placed on a glass (S-TIH, manufactured by Ohara Corporation) with a thickness of 1 mm. A quartz glass with a thickness of 1 mm was placed thereon through the spacer, and the uncured resin composition was spread. Next, the spacer was removed, and glass S-TIM8 used for the element was further placed on the quartz glass, and from above, using a high-pressure mercury lamp (UL750, manufactured by HOYA CANDEO OPTRONICS), at 20 mW / cm 2 (=Illuminance at a wavelength of 405 nm passing through the quartz glass and S-TIM8) for 2500 seconds (50 J / cm 2 ) and irradiated with light. After curing the resin composition and peeling off the quartz glass, the annealed product at 80 °C for 16 hours was used as a sample for optical property evaluation. The shape of the cured cured product was 500 μm in thickness and 5 mm × 20 mm in size within the glass surface.

[0070] For the obtained samples, the refractive indices nf of f-line (486.1 nm) of P-polarization (in the thickness direction) and S-polarization (in the plane of the incident surface), the refractive index nd of d-line (587.6 nm), and the refractive index nc of c-line (656.3 nm) were measured from the glass side. The measurement was carried out using a refractometer (KPR-30, manufactured by Shimadzu Corporation). The measurement was performed multiple times and the average value was taken as the refractive index at each wavelength.

[0071] Also, the birefringence is the refractive index n d S of S-polarization (in-plane direction) of the refractive index nd of d-line (587.6 nm) d p and the difference Δnd = n d S - n d p was defined as such.

[0072] Also, the Abbe number was calculated from each measured refractive index. The Abbe number νd was calculated by the following formula. Abbe number νd = (nd - 1) / (nf - nc)

[0073] (Evaluation of internal transmittance) The internal transmittance of the cured products of the optical elements in the examples and comparative examples was evaluated by preparing samples for optical property evaluation. Note that it is also possible to evaluate by peeling the transparent substrate from the optical element and taking out the cured product without using the sample for optical property evaluation. First, the method for preparing the sample for optical property evaluation will be described.

[0074] On a glass (BSL7, manufactured by Ohara Corporation) with a thickness of 1 mm, a spacer with a thickness of 500 μm and an uncured resin composition, which is a precursor of the cured product to be measured, were placed. A quartz glass with a thickness of 1 mm was placed thereon through the spacer, and the uncured resin composition was spread. Next, the spacer was removed, and glass S-TIM8 used for the element was further placed on the quartz glass. From above, using a high-pressure mercury lamp (UL750, manufactured by HOYA CANDEO OPTRONICS), 20 mW / cm 2(Illuminance at a wavelength of 405 nm through fused silica and S-TIM8) for 2500 seconds (50 J / cm 2 ), and the light was irradiated. After curing the resin composition and peeling off the fused silica, the sample annealed at 80 °C for 32 hours was used as a sample for optical property evaluation. The shape of the cured cured product was 500 μm in thickness and 5 mm × 20 mm in size within the glass surface.

[0075] For the obtained sample, using a spectrophotometer (UH4150, manufactured by Hitachi High-Technologies Corporation), the transmittance in the visible region (λ 400 to 700 nm) was measured and converted to the internal transmittance from the refractive indices of the glass substrate and the resin.

[0076] (Minimum thickness d1, maximum thickness d2) The minimum thickness d1 and the maximum thickness d2 of the cured products of the optical elements in the examples and comparative examples were evaluated using an optical element provided with a cured product on a transparent substrate.

[0077] First, the prepared optical element was placed in a constant temperature bath at 80 °C for 16 hours. Subsequently, the optical element was taken out in a room temperature environment (23 °C ± 2 °C), and after 20 minutes, the surface shape of the cured product was evaluated using a shape measuring machine (Form Talysurf Laser, manufactured by TAYLOR HOBSON). The measurement was performed by linearly scanning the light from one end of the optical element through the center part to the other end, and the scanning speed was 0.5 mm / sec. The vertical distance from the interface between the transparent substrate 1 and the cured product 2 to the measured surface shape of the cured product 2 was calculated to obtain the thickness D of the cured product 2. The thickness D is shown in Fig. 4. Further, the average value of the obtained thickness in the radial direction was defined as D0, the minimum thickness was defined as d1, and the maximum thickness was defined as d2.

[0078] [Fabrication of optical element] (Example 1) First, the resin composition 2a was prepared. As the first monomer having a polymerizable functional group of a bifunctional (meth)acrylate having a fluorene skeleton, 9,9-bis[4-(2-hydroxyethoxy)phenyl]fluorene diacrylate (A-1: bifunctional, A-BPEF, manufactured by Shin-Nakamura Chemical Co., Ltd.) was prepared.

[0079] Next, as the second monomer having a polymerizable functional group of a monofunctional (meth)acrylate having an alicyclic skeleton, dicyclopentenyl oxyethyl methacrylate (B-1: monofunctional, FA-512M, manufactured by Resonac Co., Ltd.) was prepared. Further, as the third monomer having a polymerizable functional group of a bifunctional (meth)acrylate having an alicyclic skeleton, tricyclodecane dimethanol diacrylate (C-1: bifunctional, A-DCP, manufactured by Shin-Nakamura Chemical Co., Ltd.) was prepared. Further, as a polymerization initiator, diphenyl(2,4,6-trimethylbenzoyl)phosphine oxide (D-1: photoinitiator, Omnirad TPO H, manufactured by IGM Resins Co., Ltd.) was prepared. Then, 29.4 parts by mass of the first monomer A-1, 29.4 parts by mass of the second monomer B-1, 39.2 parts by mass of the third monomer B-4, and 2 parts by mass of the polymerization initiator D-1 were put into a bottle and mixed uniformly to obtain the resin composition 2a of Example 1. The characteristics of the resin composition 2a of Example 1 are summarized in Table 1.

[0080] Next, using the manufacturing method shown in FIG. 2, the optical element shown in FIG. 1 was manufactured. As the transparent substrate 1, an optical glass (S-TIM8, manufactured by Ohara Inc.) having a diameter of 32 mm was prepared. The shape was such that one surface (the first surface 1A) had a concave spherical shape with an R of 40 mm, and the other surface (the second surface 1B) had a convex spherical shape with an R of 75 mm. As the mold 4, a NiP layer plated on a metal base material was machined by a precision machining machine to form a shape in which the aspherical shape of the cured product 2 to be molded was inverted.

[0081] Subsequently, the resin composition 2a of Example 1 was filled between the transparent substrate 1 and the mold 4. Then, in order to cure the resin composition 2a, ultraviolet light with an intensity of 20 mW / cm at a wavelength of 405 nm was irradiated onto the entire surface for 2500 seconds. After releasing the mold 4, by heating at 80°C for 24 hours, a cured product 2 was formed on the first surface 1A of the transparent substrate 1, and the optical element 10 of Example 1 was obtained. 2 of ultraviolet light was irradiated onto the entire surface for 2500 seconds. After releasing the mold 4, by heating at 80°C for 24 hours, a cured product 2 was formed on the first surface 1A of the transparent substrate 1, and the optical element 10 of Example 1 was obtained.

[0082] The water absorption expansion rate of the cured product 2 of the optical element of Example 1 was 0.12%, and since no peeling was observed, the evaluation was A. Also, the refractive index nd of the d-line of the cured product 2 of Example 1 was 1.575, and the Abbe number νd was 35.6. The birefringence was -0.00034, which was sufficiently small. Furthermore, the internal transmittance was 93.0%, which was good.

[0083] The cured product 2 in the optical element of Example 1 had a shape where the thickness was minimum at the center and maximum at the peripheral part. The minimum thickness d1 was 50 μm, the maximum thickness d2 was 400 μm, and d2 / d1 was 8.0. The characteristics of the cured product 2 of Example 1 are summarized in Table 2.

[0084]

Table 1

[0085]

Table 2

[0086] In Table 1, the types of the first monomer, the second monomer, the polymer, the third monomer, other monomers, and the initiator are as follows.

[0087] [First Material] (First Monomer) A-1: 9,9-bis[4-(2-hydroxyethoxy)phenyl]fluorene diacrylate (bifunctional, A-BPEF, manufactured by Shin-Nakamura Chemical Co., Ltd.) [Second Material] (Second Monomer) B-1: Dicyclopentenyl oxyethyl methacrylate (monofunctional, FA-512M, manufactured by Resonaak Co., Ltd.) B-2: Polymer of dicyclopentenyl oxyethyl methacrylate (monofunctional, FA-512M, manufactured by Resonaak Co., Ltd.) B-3: Dicyclopentanyl methacrylate (monofunctional, FA-513M, manufactured by Resonaak Co., Ltd.) B-4: Dicyclopentanyl methacrylate (monofunctional, FA-513M, manufactured by Resonaas Co., Ltd.) polymer B-5: Isobornyl methacrylate (monofunctional, IB-X, manufactured by Kyoeisha Chemical Co., Ltd.) B-6: 2-Ethyl-2-methacryloyloxyadamantane (monofunctional, manufactured by Tokyo Chemical Industry Co., Ltd.) (The third monomer) C-1: Dimethylol-tricyclodecane diacrylate (bifunctional, A-DCP, manufactured by Shin-Nakamura Chemical Co., Ltd.) [Others] (Other monomers) E-1: Ethoxylated bisphenol A diacrylate (bifunctional, ABE-300, manufactured by Shin-Nakamura Chemical Co., Ltd.) E-2: Trimethylolpropane trimethacrylate (trifunctional, TMPT, manufactured by Shin-Nakamura Chemical Co., Ltd.) (Initiator) D-1: Diphenyl(2,4,6-trimethylbenzoyl)phosphine oxide (photoinitiator, Omnirad TPO H, manufactured by IGM Resins Co., Ltd.)

[0088] (Example 2) In Example 2, the composition ratio of the resin composition is different from that of Example 1. Specifically, 19.6 parts by mass of the first monomer A-1, 39.2 parts by mass of the second monomer B-1, 39.2 parts by mass of the third monomer C-1, and 2 parts by mass of the polymerization initiator D-1 were put into a bottle and mixed uniformly to obtain the resin composition 2a of Example 2. The characteristics of the resin composition 2a of Example 2 are summarized in Table 1. This is different from Example 1 in that it was prepared. Also, the shape of Mold 4 is different from that of Example 1. Except for these points, the optical element of Example 2 was produced in the same manner as in Example 1.

[0089] The water absorption expansion rate of the cured product of the optical element of Example 2 was 0.13%, and since no peeling was observed, the evaluation was A. Also, the refractive index nd of the d-line of the cured product 2 of Example 2 was 1.561, and the Abbe number νd was 39.5. The birefringence was -0.00026, which was sufficiently small. Furthermore, the internal transmittance at a thickness of 500 μm and a wavelength of 400 nm was 92.0%, which was good.

[0090] The cured product in the optical element of Example 2 had a shape where the thickness was minimum at the central part and maximum at the peripheral part. The minimum thickness d1 was 30 μm, the maximum thickness d2 was 380 μm, and d2 / d1 was 12.7. The characteristics of the cured product 2 of Example 2 are summarized in Table 2.

[0091] (Example 3) In Example 3, the composition ratio of the resin composition is different from that of Example 1. Specifically, 10.8 parts by mass of the first monomer A-1, 48.0 parts by mass of the second monomer B-1, 39.2 parts by mass of the third monomer C-1, and 2 parts by mass of the polymerization initiator D-1 were put into a bottle and mixed uniformly to obtain the resin composition 2a of Example 3. The optical element of Example 3 was produced in the same manner as in Example 1 except for other points. The characteristics of the resin composition 2a of Example 3 are summarized in Table 1.

[0092] The water absorption expansion rate of the cured product of the optical element of Example 3 was 0.14%, and since no peeling was confirmed, the evaluation was A. Also, the refractive index nd of the d-line of the cured product 2 of Example 3 was 1.549, and the Abbe number νd was 44.3. The birefringence was -0.00019, which was sufficiently small. Furthermore, the internal transmittance at a thickness of 500 μm and a wavelength of 400 nm was 93.0%, which was good.

[0093] The cured product in the optical element of Example 3 had a shape where the thickness was minimum at the central part and maximum at the peripheral part. The minimum thickness d1 was 50 μm, the maximum thickness d2 was 400 μm, and d2 / d1 was 8.0. The characteristics of the cured product 2 of Example 3 are summarized in Table 2.

[0094] (Example 4) Example 4 differs from Example 1 in the composition of the resin composition. First, as the second monomer of the monofunctional (meth)acrylate having an alicyclic skeleton, dicyclopentenyl oxyethyl methacrylate (B-1: monofunctional, FA-512M, manufactured by Resonac Co., Ltd.) was prepared. After mixing 100 parts by mass of this dicyclopentenyl oxyethyl methacrylate and 100 parts by mass of toluene, 1 part by mass of AIBN (2,2'-azobis(isobutyronitrile), manufactured by Tokyo Chemical Industry Co., Ltd.) was mixed. Then, while bubbling with nitrogen gas, it was heated at 60 °C for 6 hours, then reprecipitated and purified with 1000 parts by mass of methanol, filtered, and vacuum dried to obtain a polymer of the second monomer. The weight average molecular weight (Mw) of the polymer was 183,000 in terms of polymethyl methacrylate conversion. This was designated as the dicyclopentenyl oxyethyl methacrylate polymer (B-2). Specifically, the composition was 23.5 parts by mass of the first monomer A-1, 29.4 parts by mass of the second monomer B-1, 15.7 parts by mass of the polymer B-2 of the second monomer, 29.4 parts by mass of the third monomer C-1, and 2 parts by mass of the polymerization initiator D-1. These were placed in a bottle and mixed uniformly to obtain the resin composition 2a of Example 4. The optical element of Example 4 was produced in the same manner as in Example 1 except for the above. The characteristics of the resin composition 2a of Example 4 are summarized in Table 1.

[0095] The water absorption expansion rate of the cured product of the optical element of Example 4 was 0.11%, and since no peeling was confirmed, the evaluation was A. Also, the refractive index nd of the d-line of the cured product 2 of Example 4 was 1.568, and the Abbe number νd was 37.8. The birefringence was -0.00029, which was sufficiently small. Furthermore, the internal transmittance at a thickness of 500 μm and a wavelength of 400 nm was 91.0%, which was good.

[0096] The cured product of the optical element of Example 4 had a shape in which the thickness was minimum at the center and maximum at the peripheral portion. The minimum thickness d1 was 50 μm, the maximum thickness d2 was 400 μm, and d2 / d1 was 8.0. The characteristics of the cured product 2 of Example 4 are summarized in Table 2.

[0097] (Example 5) Example 5 differs from Example 1 in the composition of the resin composition. As other monomers, ethoxylated bisphenol A diacrylate (E-1: ABE-300, bifunctional, manufactured by Shin-Nakamura Chemical Co., Ltd.) having no fluorene skeleton and alicyclic skeleton was used. Specifically, the composition was 19.6 parts by mass of the first monomer A-1, 44.1 parts by mass of the second monomer B-1, 29.4 parts by mass of the third monomer C-1, 4.9 parts by mass of E-1, and 2 parts by mass of the polymerization initiator D-1. These were put into a bottle and mixed uniformly to obtain the resin composition 2a of Example 5. The optical element of Example 5 was produced in the same manner as in Example 1 except for other points. The characteristics of the resin composition 2a of Example 5 are summarized in Table 1.

[0098] The water absorption expansion rate of the cured product of the optical element of Example 5 was 0.13%, and since no peeling was confirmed, the evaluation was A. Also, the refractive index nd of the d-line of the cured product 2 of Example 5 was 1.563, and the Abbe number νd was 38.9. The birefringence was -0.00028, which was sufficiently small. Furthermore, the internal transmittance at a thickness of 500 μm and a wavelength of 400 nm was 90.0%, which was good.

[0099] The cured product in the optical element of Example 5 had a shape in which the thickness was minimum at the center and maximum at the peripheral portion. The minimum thickness d1 was 50 μm, the maximum thickness d2 was 400 μm, and d2 / d1 was 8.0. The characteristics of the cured product 2 of Example 5 are summarized in Table 2.

[0100] (Example 6) Example 6 differs from Example 5 in the composition ratio of the resin composition. Specifically, the composition was 10.8 parts by mass of the first monomer A-1, 48 parts by mass of the second monomer B-1, 29.4 parts by mass of the third monomer C-1, 9.8 parts by mass of E-1, and 2 parts by mass of the polymerization initiator D-1. These were put into a bottle and mixed uniformly to obtain the resin composition 2a of Example 6. The optical element of Example 6 was produced in the same manner as in Example 5 except for other points. The characteristics of the resin composition 2a of Example 6 are summarized in Table 1.

[0101] The water absorption expansion rate of the cured product of the optical element of Example 6 was 0.14%, and since no peeling was observed, the evaluation was A. Also, for the cured product 2 of Example 6, the refractive index nd of the d-line was 1.552 and the Abbe number νd was 42.7. The birefringence was -0.00023, which was sufficiently small. Furthermore, the internal transmittance at a thickness of 500 μm and a wavelength of 400 nm was 89.0%, which was good.

[0102] The cured product in the optical element of Example 6 had a shape where the thickness was minimum at the center and maximum at the peripheral portion. The minimum thickness d1 was 50 μm, the maximum thickness d2 was 400 μm, and d2 / d1 was 8.0. The characteristics of the cured product 2 of Example 6 are summarized in Table 2.

[0103] (Example 7) In Example 7, the composition of the resin composition was different from that of Example 1. Dicyclopentanyl methacrylate (B-3: FA-513M, manufactured by Resonac Co., Ltd.) was used as the second monomer. Specifically, the composition was 29.4 parts by mass of the first monomer A-1, 29.4 parts by mass of the second monomer B-3, 39.2 parts by mass of the third monomer C-1, and 2 parts by mass of the polymerization initiator D-1. These were put into a bottle and mixed uniformly to obtain the resin composition 2a of Example 7. The optical element of Example 7 was produced in the same manner as in Example 1 except for other points. The characteristics of the resin composition 2a of Example 7 are summarized in Table 1.

[0104] The water absorption expansion rate of the cured product of the optical element of Example 7 was 0.11%, and since no peeling was observed, the evaluation was A. Also, for the cured product 2 of Example 7, the refractive index nd of the d-line was 1.571 and the Abbe number νd was 35.8. The birefringence was -0.00035, which was sufficiently small. Furthermore, the internal transmittance at a thickness of 500 μm and a wavelength of 400 nm was 93.0%, which was good.

[0105] The cured product in the optical element of Example 7 had a shape where the thickness was minimum at the center and maximum at the peripheral portion. The minimum thickness d1 was 50 μm, the maximum thickness d2 was 400 μm, and d2 / d1 was 8.0. The characteristics of the cured product 2 of Example 7 are summarized in Table 2.

[0106] (Example 8) In Example 8, the composition of the resin composition is different from that of Example 7. As the second monomer of the monofunctional (meth)acrylate having an alicyclic skeleton, dicyclopentanyl methacrylate (B-3: monofunctional, FA-513M, manufactured by Resonac Co., Ltd.) was used. After mixing 100 parts by mass of this dicyclopentanyl methacrylate and 100 parts by mass of toluene, 1 part by mass of AIBN (2,2'-azobis(isobutyronitrile), manufactured by Tokyo Chemical Industry Co., Ltd.) was mixed. Then, while bubbling with nitrogen gas, it was heated at 60 °C for 6 hours, then reprecipitated and purified with 1000 parts by mass of methanol, filtered, and vacuum dried to obtain a polymer of the second monomer. The weight average molecular weight (Mw) of the polymer was 173,000 in terms of polymethyl methacrylate. This was designated as the dicyclopentanyl methacrylate polymer (B-4). Specifically, the composition was 29.4 parts by mass of the first monomer A-1, 29.4 parts by mass of the second monomer B-3, 9.8 parts by mass of the polymer B-4 of the second monomer, 29.4 parts by mass of the third monomer C-1, and 2 parts by mass of the polymerization initiator D-1. These were put into a bottle and mixed uniformly to obtain the resin composition 2a of Example 8. The optical element of Example 8 was produced in the same manner as in Example 7 except for this. The characteristics of the resin composition 2a of Example 8 are summarized in Table 1.

[0107] The water absorption expansion rate of the cured product of the optical element of Example 8 was 0.09%, and since no peeling was confirmed, the evaluation was A. Also, the refractive index nd of the d-line of the cured product 2 of Example 8 was 1.570, and the Abbe number νd was 35.8. The birefringence was -0.00036, which was sufficiently small. Furthermore, the internal transmittance at a thickness of 500 μm and a wavelength of 400 nm was 93.0%, which was good.

[0108] The cured product of the optical element of Example 8 had a shape in which the thickness was minimum at the center and maximum at the peripheral edge. The minimum thickness d1 was 50 μm, the maximum thickness d2 was 400 μm, and d2 / d1 was 8.0. The characteristics of the cured product 2 of Example 8 are summarized in Table 2.

[0109] (Example 9) Example 9 differs from Example 1 in the composition of the resin composition. Isobornyl methacrylate (B-5: IB-X, manufactured by Kyoeisha Chemical Co., Ltd.) was used as the second monomer. Specifically, the composition was 29.4 parts by mass of the first monomer A-1, 29.4 parts by mass of the second monomer B-5, 39.2 parts by mass of the third monomer C-1, and 2 parts by mass of the polymerization initiator D-1. These were placed in a bottle and mixed uniformly to obtain the resin composition 2a of Example 9. The optical element of Example 9 was produced in the same manner as in Example 1 except for other points. The characteristics of the resin composition 2a of Example 9 are summarized in Table 1.

[0110] The water absorption expansion rate of the cured product of the optical element of Example 9 was 0.10%, and since no peeling was confirmed, the evaluation was A. Also, the refractive index nd of the d-line of the cured product 2 of Example 9 was 1.571, and the Abbe number νd was 35.8. The birefringence was -0.00034, which was sufficiently small. Furthermore, the internal transmittance at a thickness of 500 μm and a wavelength of 400 nm was 93.0%, which was good.

[0111] The cured product in the optical element of Example 9 had a shape in which the thickness was minimum at the center and maximum at the peripheral edge. The minimum thickness d1 was 50 μm, the maximum thickness d2 was 400 μm, and d2 / d1 was 8.0. The characteristics of the cured product 2 of Example 9 are summarized in Table 2.

[0112] (Example 10) Example 10 differs from Example 1 in the composition of the resin composition. 2-Ethyl-2-methacryloyloxyadamantane (B-6: manufactured by Tokyo Chemical Industry Co., Ltd.) was used as the second monomer. Specifically, the composition was 29.4 parts by mass of the first monomer A-1, 29.4 parts by mass of the second monomer B-6, 39.2 parts by mass of the third monomer C-1, and 2 parts by mass of the polymerization initiator D-1. These were placed in a bottle and mixed uniformly to obtain the resin composition 2a of Example 10. The optical element of Example 10 was produced in the same manner as in Example 1 except for other points. The characteristics of the resin composition 2a of Example 10 are summarized in Table 1.

[0113] The water absorption expansion rate of the cured product of the optical element of Example 10 was 0.10%, and since no peeling was observed, the evaluation was A. Further, the refractive index nd of the d-line of the cured product 2 of Example 10 was 1.575, and the Abbe number νd was 35.6. The birefringence was -0.00034, which was sufficiently small. Furthermore, the internal transmittance at a thickness of 500 μm and a wavelength of 400 nm was 93.0%, which was good.

[0114] The cured product in the optical element of Example 10 had a shape where the thickness was minimum at the center and maximum at the peripheral edge. The minimum thickness d1 was 50 μm, the maximum thickness d2 was 400 μm, and d2 / d1 was 8.0. The characteristics of the cured product 2 of Example 10 are summarized in Table 2.

[0115] (Comparative Example 1) Comparative Example 1 differs from Example 5 in the composition ratio of the resin composition. Specifically, the composition was 19.6 parts by mass of the first monomer A-1, 9.8 parts by mass of the second monomer B-1, 29.4 parts by mass of the third monomer C-1, 39.2 parts by mass of E-1, and 2 parts by mass of the polymerization initiator D-1. These were put into a bottle and mixed uniformly to obtain the resin composition 2a of Comparative Example 1. An optical element of Comparative Example 2 was produced in the same manner as in Example 5 except for other points. The characteristics of the resin composition 2a of Comparative Example 1 are summarized in Table 1.

[0116] The water absorption expansion rate of the cured product of the optical element of Comparative Example 1 was 0.17%, and since no peeling was observed, the evaluation was A. Further, the refractive index nd of the d-line of the cured product 2 of Comparative Example 1 was 1.571, and the Abbe number νd was 35.2. The birefringence was -0.00043. Furthermore, the internal transmittance at a thickness of 500 μm and a wavelength of 400 nm was 90.0%, which was good.

[0117] The cured product in the optical element of Comparative Example 1 had a shape where the thickness was minimum at the center and maximum at the peripheral edge. The minimum thickness d1 was 50 μm, the maximum thickness d2 was 400 μm, and d2 / d1 was 8.0. The characteristics of the cured product 2 of Comparative Example 1 are summarized in Table 2.

[0118] (Comparative Example 2) Comparative Example 2 differs from Example 1 in the composition of the resin composition. Trimethylolpropane trimethacrylate (E-2:TMPT, trifunctional, manufactured by Shin-Nakamura Chemical Co., Ltd.) having no fluorene skeleton and alicyclic skeleton was used. Specifically, the composition was 29.4 parts by mass of the first monomer A-1, 4.9 parts by mass of the second monomer B-1, 29.4 parts by mass of the third monomer C-1, 34.3 parts by mass of E-2, and 2 parts by mass of the polymerization initiator D-1. These were put into a bottle and mixed uniformly to obtain the resin composition 2a of Comparative Example 2. The optical element of Comparative Example 2 was produced in the same manner as in Example 1 except for the above. The characteristics of the resin composition 2a of Comparative Example 2 are summarized in Table 1.

[0119] Since the water absorption expansion rate of the cured product of the optical element of Comparative Example 2 was 0.35%, the evaluation was C. Further, the refractive index nd of the d-line of the cured product 2 of Comparative Example 2 was 1.573, and the Abbe number νd was 35.6. The birefringence was -0.00046. Furthermore, the internal transmittance at a thickness of 500 μm and a wavelength of 400 nm was 90.0%, which was good.

[0120] The cured product of the optical element of Comparative Example 3 had a shape in which the thickness was minimum at the center and maximum at the peripheral portion. The minimum thickness d1 was 50 μm, the maximum thickness d2 was 400 μm, and d2 / d1 was 8.0. The characteristics of the cured product 2 of Comparative Example 3 are summarized in Table 2.

[0121] From Table 2, in Examples 1 to 10 where the sum of the contents of the first monomer, the second monomer, the polymer of the second monomer, and the third monomer was in the range of 70% by mass or more and 99.5% by mass or less, the water absorption expansion rate was less than 0.30%, and the birefringence was as small as less than 0.0004.

[0122] From the above, it was found that according to the present disclosure, it is possible to provide a resin composition having a small birefringence and being less likely to change optical performance even in a high-humidity environment.

[0123] The disclosure of this embodiment includes the following configurations and methods.

[0124] (Configuration 1) A first monomer having a polymerizable functional group of a bifunctional (meth)acrylate having a fluorene skeleton represented by the following general formula (1), a second monomer having a polymerizable functional group of a monofunctional (meth)acrylate having an alicyclic skeleton represented by any one of the following general formulas (2) to (5), a polymer of the second monomer, and at least one of a third monomer having a polymerizable functional group of a bifunctional (meth)acrylate having an alicyclic skeleton represented by any one of the following general formulas (2) to (5), a resin composition, characterized in that the sum of the contents of the first monomer, the second monomer, the polymer of the second monomer, and the third monomer is in the range of 70% by mass or more and 99.5% by mass or less.

[0125]

Chemical formula

[0126] (In the general formula (1), at least two of R 11 ~R 20 have a polymerizable functional group of (meth)acrylate, and the others are a hydrogen atom or an organic group.)

[0127]

Chemical formula

[0128]

Chemical formula

[0129]

Chemical formula

[0130]

Chemical formula

[0131] (In general formula (5), R is a hydrogen atom, an alkyl group, or a substituted or unsubstituted alkylene group.)

[0132] (Constitution 2) The resin composition according to Constitution 1, wherein the first monomer is represented by the following general formula (6).

[0133] [Chemical formula]

[0134] (In general formula (6), R1 and R3 are)

[0135] [Chemical formula]

[0136] any one of them, and R2 and R4 are any one of a hydrogen atom, CH2, and an alkyl group.)

[0137] (Constitution 3) The resin composition according to Constitution 1 or 2, wherein the content of the first monomer is in the range of 10% by mass or more and 30% by mass or less.

[0138] (Constitution 4) The resin composition according to any one of Constitutions 1 to 3, wherein the sum of the contents of the second monomer, the polymer of the second monomer, and the third monomer is in the range of 40% by mass or more and 85.9% by mass or less.

[0139] (Constitution 5) The resin composition according to any one of Constitutions 1 to 4, which has the second monomer and the third monomer.

[0140] (Constitution 6) A transparent substrate, and a cured product of the resin composition according to any one of Constitutions 1 to 5 provided on the transparent substrate, and an optical element characterized by comprising the same.

[0141] (Configuration 7) The refractive index nd of the cured product is in the range of 1.54 or more and 1.58 or less, The optical element according to Configuration 6, wherein the Abbe number νd of the cured product is in the range of 30 or more and less than 45.

[0142] (Configuration 8) The optical element according to Configuration 6 or 7, wherein the difference between the refractive index in the plane of the surface of the cured product facing the substrate and the refractive index in the thickness direction of the cured product is within 0.0004.

[0143] (Configuration 9) The optical element according to any one of Configurations 6 to 8, wherein the internal transmittance of the cured product at a wavelength of 400 nm in terms of a thickness of 500 μm is 70% or more.

[0144] (Configuration 10) The transparent substrate has a first concave spherical surface, The optical element according to any one of Configurations 6 to 9, wherein the cured product is provided on the first surface.

[0145] (Configuration 11) The optical element according to Configuration 10, wherein the ratio of the maximum thickness d2 to the minimum thickness d1 of the cured product is greater than 1 and in the range of 30 or less.

[0146] (Configuration 12) The optical element according to Configuration 11, wherein the minimum thickness d1 is 300 μm or less, and the maximum thickness d2 is in the range of 10 μm or more and 1000 μm or less.

[0147] (Configuration 13) The optical element according to any one of Configurations 6 to 12, wherein the water absorption expansion rate of the cured product is less than 0.30%.

[0148] (Configuration 14) An optical device having a housing and an optical system having at least one lens disposed within the housing, An optical device, wherein at least one of the lenses is the optical element according to any one of Configurations 6 to 13.

[0149] (Configuration 15) An imaging device including a housing, an optical system having at least one lens disposed within the housing, and an imaging element that receives light that has passed through the optical system, An imaging device, wherein at least one of the lenses is the optical element according to any one of Configurations 6 to 13.

[0150] (Method 1) A preparation step of preparing a transparent substrate and the resin composition according to any one of Configurations 1 to 5, An installation step of forming and providing the resin composition on the transparent substrate using a mold, A curing step of polymerizing or copolymerizing the resin composition to form a cured product, A method for manufacturing an optical element, characterized by including the above steps.

[0151] (Method 2) The method for manufacturing an optical element according to Method 1, wherein the curing step includes a light irradiation step of polymerizing or copolymerizing the resin composition by light irradiation.

Explanation of Reference Numerals

[0152] 1 Transparent substrate 1A First surface 1B Second surface 2 Cured product 2a Resin composition 4 Mold 5 Injector 10 Optical element 600 Single-lens reflex digital camera (imaging device) 601 Lens barrel (interchangeable lens, optical device) 602 Camera body 603 Lens (optical element) 604 Inner cylinder 605 Lens (optical element) 606 Diaphragm 607 Main mirror 608 Sub-mirror 609 Shutter 610 Image sensor 611 Prism 621 Housing

Claims

1. a first monomer having a polymerizable functional group of a bifunctional (meth)acrylate having a fluorene skeleton represented by the following general formula (1); a second monomer having a polymerizable functional group of a monofunctional (meth)acrylate having an alicyclic skeleton represented by any one of the following general formulas (2) to (5), a polymer of the second monomer, and a third monomer having a polymerizable functional group of a bifunctional (meth)acrylate having an alicyclic skeleton represented by any one of the following general formulas (2) to (5), and having at least one of them; a resin composition, wherein the sum of the contents of the first monomer, the second monomer, the polymer of the second monomer, and the third monomer is in the range of 70% by mass or more and 99.5% by mass or less. 【Chemical 1】 (In the general formula (1), R １１ ~R ２０ At least two of the groups have a polymerizable functional group of (meth)acrylate, and the others are hydrogen atoms or organic groups. 【Chemical Formula 2】 【Chemical Formula 3】 [Chemical Formula 4] 【Chemical Formula 5】 (In general formula (5), R is a hydrogen atom, an alkyl group, a substituted or unsubstituted alkylene group.)

2. The resin composition according to claim 1, wherein the first monomer is represented by the following general formula (6). 【Chemical Formula 6】 (In general formula (6), R １ and R ３ are 【Chemical Formula 7】 is any one of them, and R ２ and R ４ is either a hydrogen atom, CH ２ or an alkyl group. )

3. The resin composition according to claim 1, wherein the content of the first monomer is in the range of 10% by mass or more and 30% by mass or less.

4. The resin composition according to claim 1, wherein the sum of the contents of the second monomer, the polymer of the second monomer, and the third monomer is in the range of 40% by mass or more and 85.9% by mass or less.

5. The resin composition according to claim 1, wherein the resin composition has the second monomer and the third monomer.

6. a transparent substrate; and a cured product of the resin composition according to any one of claims 1 to 5 provided on the transparent substrate, and an optical element characterized by comprising the same.

7. The refractive index nd of the cured product is in the range of 1.54 or more and 1.58 or less, and The Abbe number νd of the cured product is in the range of 30 or more and less than 45. The optical element according to claim 6.

8. The difference between the refractive index in the plane of the surface of the cured product facing the transparent substrate and the refractive index in the thickness direction of the cured product is within 0.0004. The optical element according to claim 6.

9. The internal transmittance of the cured product at a wavelength of 400 nm in terms of a thickness of 500 μm is 70% or more. The optical element according to claim 6.

10. The transparent substrate has a first concave spherical surface, and The cured product is provided on the first surface. The optical element according to claim 9.

11. The optical element according to claim 9, wherein the ratio of the maximum thickness d2 to the minimum thickness d1 of the cured product is greater than 1 and in the range of 30 or less.

12. The optical element according to claim 11, wherein the minimum thickness d1 is 300 μm or less and the maximum thickness d2 is in the range of 10 μm or more and 1000 μm or less.

13. The optical element according to claim 6, wherein the water absorption expansion rate of the cured product is less than 0.30%.

14. An optical device having a housing and an optical system having at least one lens disposed within the housing, The optical device, wherein at least one of the lenses is the optical element according to claim 6.

15. An imaging device having a housing, an optical system having at least one lens disposed within the housing, and an imaging element that receives light that has passed through the optical system, The imaging device, wherein at least one of the lenses is the optical element according to claim 6.

16. A preparation step of preparing a transparent substrate and the resin composition according to any one of claims 1 to 5; An installation step of forming and providing the resin composition on the transparent substrate using a mold; A curing step of polymerizing or copolymerizing the resin composition to form a cured product; A method for manufacturing an optical element, characterized by including the above steps.

17. The method for manufacturing an optical element according to claim 16, wherein the curing step includes a light irradiation step of polymerizing or copolymerizing the resin composition by light irradiation.

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