Optical elements, resin compositions, optical instruments, and imaging devices

Abstract

This provides a replica element with a low water absorption expansion coefficient, high refractive index, and excellent durability. [Solution] An optical element is provided on a transparent substrate, comprising a resin composition containing a polyfunctional urethane-modified (meth)acrylate compound, a bifunctional (meth)acrylate compound having a bisphenol skeleton, and a polymer obtained by polymerizing a polymerizable compound (monomer) having one of the following skeletons: tricyclodecane skeleton, isobornyl skeleton, dicyclopentenyl skeleton, or adamantane skeleton, and a cured product obtained by polymerizing and curing the resin composition.

Description

[Technical Field]

[0001] This disclosure relates to an optical element, a resin composition used in its manufacture, an optical instrument using the optical element, and an imaging device. [Background technology]

[0002] One type of optical element known is a lens in which a cured resin composition is provided on a transparent substrate such as glass. Such lenses are manufactured by using a mold, filling the space between the substrate and the mold with the resin composition, and polymerizing or copolymerizing it to form a cured material of the desired shape on the substrate surface. Lenses manufactured by this method are called replica elements. Replica elements are effective for use as aspherical lenses and Fresnel lenses because they can easily form the desired surface shape. An aspherical lens is a general term for a lens in which the curvature changes continuously 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] Japanese Patent Application Publication No. 6-298886 [Patent Document 2] U.S. Patent No. 7070862 [Overview of the Initiative] [Problems that the invention aims to solve]

[0004] However, the cured resin composition disclosed in Patent Document 1 has a high coefficient of water absorption and expansion, which presents a problem in that its optical performance is easily altered in high-humidity environments, for example. Furthermore, the cured resin composition disclosed in Patent Document 2 has a higher refractive index compared to Patent Document 1, which has the advantage of allowing for a lower resin thickness even with a large aspherical effect, and its coefficient of water absorption and expansion is lower than that of Patent Document 1. However, when the aspherical effect is increased, the film thickness increases, resulting in insufficient water absorption characteristics. In addition, there are considered to be issues with environmental durability. The object of the present invention is to provide a replica element with a low water absorption expansion coefficient, a high refractive index, and excellent durability. [Means for solving the problem]

[0005] A first embodiment for solving the above problem is a resin composition characterized by containing at least the following components (A) to (C). (A) Polyfunctional urethane-modified (meth)acrylate compound (B) Difunctional (meth)acrylate compounds having a bisphenol skeleton represented by the following general formula (1) (C) A polymer represented by the following general formula (6) having at least one alicyclic skeleton represented by the following structural formulas (2) to (4) and general formula (5).

[0006] [ka]

[0007] [ka] [In the above general formula (1), R1 and R2 each independently represent a hydrogen atom or a methyl group, and m and n represent numerical values.] In the above general formula (5), R is a hydrogen atom, an alkyl group, or a substituted or unsubstituted alkylene group. In the above general formula (6), R1 represents a hydrogen atom or a methyl group, n is 0 or 1, a is a numerical value, and X represents the alicyclic skeleton shown in any of the above structural formulas (2) to (4) and general formula (5). A second aspect for solving the above problems is an optical element including a cured product of the resin composition according to the first aspect, where the glass transition point of the cured product is 105°C or higher and 160°C or lower, and the refractive index of the cured product at the d line is 1.54 or higher. [Advantages of the Invention]

[0008] According to the above aspect, an optical element with a low water absorption expansion rate, less likely to have its optical performance fluctuate even in a high-temperature environment, and excellent durability can be provided. Further, a resin composition used for the optical element, an optical device using the optical element, and an imaging device can be provided. [Brief Description of the Drawings]

[0009] [Figure 1] It is a schematic diagram showing an embodiment of an optical element according to the present disclosure. [Figure 2] It is a schematic diagram showing an embodiment of a method for manufacturing an optical element according to the present disclosure. [Figure 3] It is a schematic diagram showing an embodiment of an imaging device according to the present disclosure. [Figure 4] It is a schematic diagram showing the thickness of a cured product in an optical element of an example. [Modes for Carrying Out the Invention]

[0010] Hereinafter, embodiments of the present disclosure will be described. [Optical Element] FIG. 1 is a schematic diagram showing an optical element according to the first embodiment, and is a side cross-sectional view obtained by cutting the optical element 10 in the stacking direction along a straight line passing through the element center O of the optical element 10. 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 a transparent substrate.

[0011] (Transparent Substrate) The transparent substrate 1 has an optical surface, a first surface 1A, and a second surface 1B. The first surface 1A of the transparent substrate 1 is either the light incident surface or the light emission surface, and the second surface 1B of the transparent substrate 1 is the other of the light incident surface or the light emission surface. The transparent substrate 1 can be a transparent resin or a transparent glass. In this specification, "transparent" means that the transmittance of light in the wavelength range of 400 nm to 780 nm is 10% or more. Glass is preferably used for the transparent substrate 1, and for example, general optical glass such as silicate glass, borosilicate glass, or phosphate glass, as well as quartz glass and glass ceramics can be used. Surface treatment with a silane coupling agent or the like may also be performed. Furthermore, a transparent organic resin layer that serves as a transparent adhesive or buffer layer may be provided between the transparent substrate 1 and the cured product 2 described later.

[0012] In Figure 1, the first surface 1A is a concave spherical shape and the second surface 1B is a convex spherical shape, 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 from concave spherical, convex spherical, axisymmetric aspherical, and planar surfaces according to desired characteristics. It is preferable that the transparent substrate 1 is circular when viewed from above in the direction of the paper in Figure 1. This is because it improves the assembly accuracy when the optical element 10 is used as a lens in the optical system described later.

[0013] (cured product) In Figure 1, the cured product 2 is provided in close contact with the first surface 1A of the transparent substrate 1. However, as mentioned above, a transparent adhesive or a transparent organic resin layer serving as a buffer layer may be provided between the transparent substrate 1 and the cured product 2. The cured product 2 is a cured product of a resin composition obtained by polymerizing or copolymerizing the resin composition. The resin composition preferably contains at least the following components (A) to (C), and further has component (D) as a polymerization initiator. (A) Polyfunctional urethane-modified (meth)acrylate compound (B) Difunctional (meth)acrylate compounds having a bisphenol skeleton represented by the following general formula (1) (C) A polymer represented by the following general formula (6) having at least one alicyclic skeleton represented by the following structural formulas (2) to (4) and general formula (5).

[0014] [ka]

[0015] [ka]

[0016] In the above general formula (1), R1 and R2 each independently represent a hydrogen atom or a methyl group, and m and n represent numerical values. m+n is preferably between 2 and 30. In the above general formula (5), R is a hydrogen atom, an alkyl group, or a substituted or unsubstituted alkylene group. In the above general formula (6), R1 represents a hydrogen atom or a methyl group, n is 0 or 1, a is a numerical value, and X represents an alicyclic skeleton shown in any of the above structural formulas (2) to (4) and general formula (5).

[0017] In general formula (6), the left end is the initiator, and the right end is the substituent that was attached at the time of polymerization termination.

[0018] The alicyclic skeleton shown in structural formula (2) is a tricyclodecane skeleton. The alicyclic skeleton shown in structural formula (3) is an isobornyl skeleton. The alicyclic skeleton shown in structural formula (4) is a dicyclopentenyl skeleton. The alicyclic skeleton shown in general formula (5) is an adamantane skeleton. Polymers obtained by polymerizing polymerizable compounds (monomers) having any of the tricyclodecane, isobornyl, dicyclopentenyl, and adamantane skeletons play a role in reducing the water absorption expansion coefficient in cured product 2. Furthermore, due to the alicyclic structure with its three-dimensional structure, it plays a role in suppressing the decrease in birefringence caused by component (A).

[0019] The resin composition of this disclosure may further contain a polymerizable compound having a monofunctional (meth)acrylate polymerizable functional group, which is the monomer of component (C) before polymerization, in order to perform the function of lowering the water absorption expansion rate. Furthermore, it may also contain a polymerizable compound having a bifunctional (meth)acrylate polymerizable functional group having an alicyclic skeleton represented by structural formulas (2) to (4) and general formula (5).

[0020] In this disclosure, the composition of components (A) to (C) is such that component (A) is 3 to 20 parts by mass, component (B) is 50 to 80 parts by mass, and component (C) is 5 to 30 parts by mass. Preferably, component (A) is 3 to 10 parts by mass, component (B) is 60 to 80 parts by mass, and component (C) is 5 to 20 parts by mass. Furthermore, if the monomer contains a polymerizable compound having a monofunctional (meth)acrylate polymerizable functional group, which is the monomer of component (C) before polymerization, it is preferable to add it to components (A) to (C) in an amount of 5 to 25 parts by mass, and the total amount with component (C) is preferably 10 to 30 parts by mass.

[0021] (A) Examples of components include compounds represented by the following general formulas (7) and (8).

[0022] [ka]

[0023] In the above general formula (7), R4 and R5 are each independently hydrogen or a methyl group, R6 and R7 are each independently a hydrocarbon group having 1 to 10 carbon atoms, R8 is an isocyanate residue, R9 is a polyol residue or a polyester residue, and q is 0 or an integer less than or equal to 10.

[0024] [ka]

[0025] In the above general formula (8), R 10 R is a hydrocarbon group having 1 to 10 carbon atoms. 11 is a substituent represented by the following general formula (9) or (10).

[0026] [ka]

[0027] In the above general formulas (9) and (10), R 13 ,R 14 and R 16 Each is independently either a hydrogen atom or a methyl group, and R 15 It is a hydrocarbon group having 1 to 10 carbon atoms.

[0028] Furthermore, the weight-average molecular weight (Mw) of component (C) is preferably in the range of 35,000 to 300,000. If it is less than 35,000, the yield will decrease in the manufacturing method of cured product 2 described later. Also, if it exceeds 300,000, the compatibility with other components may not be sufficient.

[0029] The polymerization initiator as component (D) may be either a polymerization initiator or a thermal polymerization initiator, and can be determined by the selected manufacturing process. However, when replica molding is performed to produce an aspherical shape, a photopolymerization initiator is preferred in terms of its fast curing speed. Examples of commercially available photopolymerization initiators include 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)-1-butanone, 1-hydroxycyclohexylphenyl ketone, bis(2,4,6-trimethylbenzoyl)-phenylphosphine oxide, 4-phenylbenzophenone, 4-phenoxybenzophenone, 4,4'-diphenylbenzophenone, and 4,4'-diphenoxybenzophenone. The content of the photopolymerization initiator in the resin composition is preferably 0.01 parts by mass or more and 10 parts by mass or less per 100 parts by mass of the total of components (A) to (C) and the polymerizable compounds added as needed. If the amount of photopolymerization initiator is less than 0.01 parts by mass, sufficient reactivity cannot be obtained, and if it exceeds 10 parts by mass, the transmittance of cured product 2 may decrease. Furthermore, unreacted polymerization initiator remains in cured product 2.

[0030] Furthermore, the resin composition may contain polymerization inhibitors, antioxidants, light stabilizers (HALS), ultraviolet absorbers, silane coupling agents, mold release agents, pigments, dyes, etc., as needed.

[0031] Furthermore, the refractive index nd of the d-line (587.6 nm) of the cured product 2 according to this disclosure is 1.54 or higher, and preferably 1.58 or lower. Increasing the refractive index can enhance the aspherical effect of the cured product 2, which is correlated with the product of the refractive index and thickness. In the cured product disclosed in Patent Document 2, when the refractive index nd was set to 1.54 or higher and formed on a transparent substrate, the birefringence sometimes became large. However, according to this disclosure, it is possible to provide a cured product 2 with a small birefringence that does not easily change optical performance even in a high-humidity environment.

[0032] Furthermore, the glass transition temperature (Tg) of cured material 2 is preferably between 100°C and 180°C, and more preferably between 105°C and 160°C. If the glass transition temperature is below 100°C, distortion will occur in the image at high temperatures, and if it is above 180°C, the resin or glass may crack or the resin may peel off the glass during environmental testing.

[0033] In Figure 1, the thickness of the cured material 2 is not uniform within the plane of the first surface 1A. That is, the shape of the surface on the side of the cured material 2 that is not in contact with the transparent substrate 1 is aspherical. In this embodiment, the thickness distribution is such that it is thin near the center O of the optical element 10, with a minimum thickness d1, and has a maximum thickness d2 at the periphery of the optical element 10, but it does not necessarily have to be this shape. For example, the thickness distribution may be such that the maximum thickness d2 is near the center O of the optical element 10, and the minimum thickness d1 is at the periphery of the element. It is preferable that the ratio of the maximum thickness d2 to the minimum thickness d1 of the cured material 2 is greater than 1 and in the range of 30 or less. If it is greater than 30, the difference in thickness of the cured material 2 is large, and there is a risk that the surface accuracy cannot be maintained with high precision during curing shrinkage. It is more preferable to be 8 or more. It is preferable that 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.

[0034] Furthermore, it is preferable that the water absorption expansion rate of the cured material 2 provided on the transparent substrate 1 is less than 0.50%. This is because it minimizes the fluctuation in optical properties due to water absorption expansion. If the water absorption expansion rate is 0.50% or higher, the change in the surface shape of the cured material 2 before and after water absorption is large, which may affect the image quality when used in an optical system. Therefore, it is preferable that it be less than 0.30%. The water absorption expansion rate is measured using a water absorption expansion meter, which measures the rate of change in length from 0% humidity to 90% humidity at a temperature of 60°C.

[0035] In this embodiment, the optical element 10 had a transparent substrate 1, but depending on the optical properties of the optical element 10, it may not have to have a transparent substrate 1.

[0036] [Manufacturing method for optical elements] The method for manufacturing the optical element according to the above-described embodiment is not particularly limited, but an example of a preferred manufacturing process will be described. Figure 2 is a schematic diagram showing the method for manufacturing the optical element according to the above-described embodiment.

[0037] First, a transparent substrate 1 and a resin composition 3 are prepared (preparation step). To improve the adhesion between the transparent substrate 1 and the cured product 2, it is preferable to pre-treat 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 that adhesion can be further improved by directly chemically bonding the first surface 1A and the cured product 2, it is preferable to perform the coupling treatment using a silane coupling agent. Specific coupling agents include, for example, hexamethyldisilazane, methyltrimethoxysilane, trimethylchlorosilane, and triethylchlorosilane. The method for obtaining the resin composition 3 is not particularly limited. The means and time for mixing are not particularly limited, but it is preferable to mix them until they are uniform.

[0038] Next, as shown in Figure 2(a), the resin composition 3 is dropped onto the mold 4. In this embodiment, the resin composition 3 is an ultraviolet-curable composition containing a photopolymerization initiator. The transparent substrate 1 is placed on the ejector 5 and positioned opposite the mold 4. The mold 4 is, for example, a mold that has a desired aspherical inverted shape on its surface and can be manufactured by cutting a metal base material such as stainless steel or steel that has been NiP plated or oxygen-free copper plated with a precision machining tool. The surface of the mold 4 may also be coated with a release agent to control the release properties of the resin. The type of release agent is not particularly limited, but for example, a fluorine coating agent can be used.

[0039] Next, as shown in Figure 2(b), the ejector 5 is lowered so that the mold 4 approaches the transparent substrate 1, thereby providing the resin composition 3 to the transparent substrate 1 (installation step). The ejector 5 is lowered further so that the uncured resin composition 3 is filled between the mold 4 and the transparent substrate 1, and the desired shape is formed (molding step).

[0040] Then, by irradiating the transparent substrate 1 with ultraviolet light from the second surface 1B side using an ultraviolet light source 6, a cured product 2, which is a polymer of the resin composition 3, is obtained (curing step, light irradiation step).

[0041] Subsequently, by releasing the cured material 2 from the mold 4, an optical element 10 having an aspherical cured material 2 on a transparent substrate 1 is obtained. Alternatively, after forming the cured material 2, additional irradiation with ultraviolet light or heat treatment may be performed in air or an oxygen-free atmosphere.

[0042] The optical element of this embodiment can be manufactured by the above manufacturing method. In the installation step, the resin composition 3 may be dropped onto both the mold 4 and the transparent substrate 1, or it may be dropped only onto the transparent substrate 1. Also, if the resin composition 3 contains a thermal polymerization initiator as a curing initiator, the light irradiation step may be changed to a heat treatment step. Furthermore, after the curing step, the transparent substrate 1 may be peeled off the optical element 10, and only the cured product 2 may be used as the optical element 10.

[0043] [Optical equipment] Specific examples of applications for the optical element of the above-described embodiment include lenses that constitute optical equipment (photographic optical systems) for cameras and video cameras, and lenses that constitute optical equipment (projection optical systems) for liquid crystal projectors. It can also be used in pickup lenses for DVD recorders and the like. These optical systems consist of at least one lens arranged within the housing, and the above-described optical element can be used in at least one of these lenses.

[0044] [Imaging device] Figure 3 is a schematic diagram showing the configuration of a single-lens reflex digital camera 100, which is an example of a preferred embodiment of an imaging device using the optical elements of the embodiment described above. In Figure 3, the camera body 12 and the lens barrel 11, which is an optical device, are coupled together, and the lens barrel 11 is a so-called interchangeable lens that can be attached to and detached from the camera body 12.

[0045] Light from the subject is captured through an optical system consisting of multiple lenses 13, 15, etc., arranged on the optical axis of the imaging optical system within the housing 30 of the lens barrel 11. The optical elements of this embodiment can be used, for example, as lenses 13 and 15. Here, lens 15 is supported by an inner barrel 14 and is movably supported relative to the outer barrel of the lens barrel 11 for focusing and zooming.

[0046] During the observation period before shooting, light from the subject is reflected by the main mirror 17 inside the camera body housing 31, passes through the prism 21, and the image is projected to the photographer through the viewfinder lens 22. The main mirror 17 is, for example, a half-mirror, and the light that passes through the main mirror is reflected by the sub-mirror 18 towards the AF (autofocus) unit 23, and this reflected light is used, for example, for distance measurement. The main mirror 17 is attached and supported by the main mirror holder 40 by adhesive or the like. During shooting, the main mirror 17 and sub-mirror 18 are moved out of the optical path via a drive mechanism (not shown), the shutter 19 is opened, and the image sensor 20 receives the light that has entered from the lens barrel 11 and passed through the shooting optical system to form a shooting image. The aperture 16 is configured to change the brightness and depth of field during shooting by changing the aperture area.

[0047] Although this explanation uses a single-lens reflex digital camera to describe the imaging device, it can be similarly used with smartphones, compact digital cameras, drones, and other devices. [Examples]

[0048] The following will provide examples and comparative examples. First, the methods for measuring and evaluating the physical properties of the examples and comparative examples will be explained.

[0049] (Molecular weight of component (C)) Weight-average molecular weight (Mw) is a value expressed in terms of polymethyl methacrylate and can be measured, for example, by gel permeation chromatography (GPC). More specifically, a calibration curve is created from the elution time and weight-average molecular weight using a polymethyl methacrylate resin with a known monodisperse weight-average molecular weight (Mw) that is available as a reagent, and an analytical gel column that elutes high molecular weight components first. Then, the weight-average molecular weight (Mw) can be determined based on the obtained calibration curve. Specifically, a RID-20A (Shimadzu Corporation) differential refractive index detector, an LF-404 (Resonac Corporation) analytical column, an LF-G (Resonac Corporation) guard column, and tetrahydrofuran as the eluent were used.

[0050] (Glass transition temperature (Tg) of the cured product) The resin composition was filled into two 100mm x 100mm x 5mm quartz substrates via a 0.2m spacer, and the intensity at a wavelength of 405nm was 10mW / cm². 2 A cured material was obtained by irradiating the entire surface with ultraviolet light for 200 seconds. The obtained cured material was cut into strips measuring 5 mm wide x 20 mm long x 0.2 mm thick, and the elastic modulus behavior was measured from 24°C to 230°C using a dynamic viscoelasticity measuring device (Rheogel-E4000, manufactured by UBM Co., Ltd.) with a length of 14.2 mm, to determine the glass transition point.

[0051] (Refractive index of line d: nd) The refractive index nd of the cured optical elements in the examples and comparative examples was evaluated by preparing samples for optical property evaluation. Alternatively, it is also possible to peel the transparent substrate from the optical element, extract the cured material, and evaluate it without using samples for optical property evaluation. First, the method for preparing the samples for optical property evaluation will be described.

[0052] A glass with a thickness of 1 mm (S-TIH, manufactured by Ohara Corporation) was placed with a spacer with a thickness of 500 μm and an uncured resin composition, which is a precursor of a cured product to be measured. A quartz glass with a thickness of 1 mm was placed on it 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 it, using a high-pressure mercury lamp (UL750, manufactured by HOYA CANDEO OPTRONICS), at 20 mW / cm 2 (= illuminance at a wavelength of 405 nm through quartz glass and S-TIM8) for 2500 seconds (50 J / cm 2 ), light was irradiated. After curing the resin composition and peeling off the quartz glass, the one annealed at 80 °C for 16 hours was used as a sample for optical property evaluation. The shape of the cured product cured by such a method was 500 μm in thickness and 5 mm × 20 mm in size within the glass surface.

[0053] For the obtained sample, the refractive index nd of the d-line (587.6 nm) of P-polarization (in the thickness direction) and S-polarization (in the plane direction of the incident plane) was measured from the glass side using a refractometer (KPR-30, manufactured by Shimadzu Corporation). The measurement was performed multiple times, and the average value was used as the refractive index.

[0054] (Water absorption expansion rate) For the cured products of the optical elements in the examples and comparative examples, a cured product of 5 mm × 20 mm (measurement site: 15 mm) × 0.2 mm was produced, and the expansion amount from a temperature of 60 °C and a humidity of 0% to 90% was measured using a water absorption expansion rate meter (TMA8310 / HUM: manufactured by Rigaku). From the length D0 at 60 °C and 0% and the length D1 at 60 °C and 90%, the water absorption expansion rate [%] of the optical element was calculated using the following formula. Water absorption expansion rate [%] = ((D1 - D0) / D0) × 100 The evaluation was performed as follows. A: Those with a water absorption expansion rate of less than 0.30% B: Those with a water absorption expansion rate of 0.50% or less C: Those with a water absorption expansion rate exceeding 0.50%

[0055] (Strain in a high-temperature environment)​The optical elements of the examples and comparative examples were compared by imaging at room temperature (23°C ± 2°C) and at a lens barrel temperature of 80°C. The evaluation criteria are as follows. ○: No distortion was observed in imaging at 80°C compared to imaging at room temperature. △: Slight distortion was observed in imaging at 80°C compared to imaging at room temperature. ×: Distortion was observed in imaging at 80°C compared to imaging at room temperature.

[0056] (Temperature cycle test) The optical elements of the examples and comparative examples were subjected to a temperature cycling test consisting of three cycles: 5 hours in a 60°C constant temperature bath, followed by 5 hours in a -30°C constant temperature bath. The presence or absence of cracks or peeling was checked. Elements without cracks or peeling were marked with "○", and those with cracks or peeling were marked with "×".

[0057] (Minimum thickness d1, maximum thickness d2) The minimum thickness d1 and maximum thickness d2 of the cured optical elements in the examples and comparative examples were evaluated using optical elements on which the cured material was provided on a transparent substrate. First, the fabricated optical element was placed in a constant temperature bath at 80°C for 16 hours. Next, the optical element was removed to room temperature (23°C ± 2°C), and after 20 minutes, the surface shape of the cured material was evaluated using a shape measuring instrument (Form Talysurf Laser, manufactured by TaylorHobson). The measurement was performed by scanning the optical element in a straight line from one end to the center and then to the opposite end, with a scanning speed of 0.5 mm / sec. The vertical distance from the interface between the transparent substrate and the cured material to the measured surface shape of the cured material was calculated to obtain the thickness D of the cured material. Figure 4 shows the thickness D. Furthermore, the radial average of the obtained thicknesses was defined as D0, the minimum thickness as d1, and the maximum thickness as d2.

[0058] [Fabrication of optical elements] The components used in the examples and comparative examples are as follows: (A) component A-1: Polyfunctional urethane-modified (meth)acrylate (R of general formula (8)) 10 R is a hydrocarbon group with 2 carbon atoms. 11This is shown by the general formula (10), and R 15 is a hydrocarbon group with 2 carbon atoms (-(CH2)2-), R 16 (Hydrogen) A-2: Polyfunctional urethane-modified (meth)acrylate (In general formula (7), R4 and R5 are hydrogen atoms, R6 to R8 are hydrocarbon groups with 4 carbon atoms (-(CH2)4-), and q is an average of 6)

[0059] (B) Component B-1: Diacrylate, an EO adduct of bisphenol A (structural formula (11) below, m+n=3.0)

[0060] [ka] B-2: Dimethacrylate, an EO adduct of bisphenol A (structural formula (12) below, m+n=2.3; the sum of m+n is a decimal because m+n is a mixture of multiple substances such as 2, 3, and 4, and this is the average).

[0061] [ka]

[0062] (C) Component C-1: Dicyclopentamethacrylate polymer (where X in general formula (6) is structural formula (2), n=0) C-2: Dicyclopentenyloxyethyl methacrylate polymer (where X in general formula (6) is structural formula (3), n=1) C-3: Isovonyl methacrylate polymer (where X in general formula (6) is structural formula (4), n=0) C-4: 2-ethyl-2-methacryloyl oxyadamantane polymer (where X in general formula (6) is general formula (5), R is an ethyl group, n=0)

[0063] (D) Component (Photopolymerization Initiator) D-1: Diphenyl(2,4,6-trimethylbenzoyl)phosphine oxide (structural formula (13) below)

[0064] [ka]

[0065] (E) Component (Other components) E-1: Dicyclopentamethacrylate (structural formula (14) below)

[0066] [ka]

[0067] E-2: Dicyclopentenyloxyethyl methacrylate (structural formula (15) below)

[0068] [ka]

[0069] E-3: Isovonyl methacrylate (structural formula (16) below)

[0070] [ka]

[0071] E-4: 2-Ethyl-2-methacryloyloxyandaman (structural formula (17) below)

[0072] [ka]

[0073] (Example 1) Each component (A) through (E) listed in Table 1 was placed in a bottle in the parts by mass listed in Table 1 and mixed uniformly to obtain a resin composition. Next, the optical element shown in Figure 1 was manufactured using the manufacturing method shown in Figure 2. A 32 mm diameter optical glass (S-TIM8, manufactured by Ohara Corporation) was prepared as the transparent substrate 1. The shape was such that one surface (first surface 1A) was a concave spherical shape with a radius of R40 mm, and the other surface (second surface 1B) was a convex spherical shape with a radius of R75 mm. For the mold 4, a NiP layer plated on a metal base material was cut using a precision machining tool to form a shape that was an inversion of the aspherical shape of the hardened product 2 to be molded.

[0074] Next, the resin composition was filled between the transparent substrate 1 and the mold 4. Afterward, an intensity of 10 mW / cm² was obtained at a wavelength of 405 nm. 2 The entire surface was irradiated with ultraviolet light for 200 seconds. After demolding mold 4, the surface was heated at 80°C for 24 hours to form a cured product 2 on the first surface 1A of the transparent substrate 1, thereby obtaining the optical element 10 of Example 1. The above evaluations were performed on the obtained optical element. The evaluation results are shown in Table 1.

[0075] (Examples 2 to 5, Comparative Examples 1 and 2) Optical elements were fabricated and evaluated in the same manner as in Example 1, except that the composition of the resin composition was changed to the composition shown in Table 1. The evaluation results are shown in Table 1.

[0076] [Table 1]

[0077] [Included components] This embodiment includes the following configuration. (Composition 1) A resin composition characterized by containing at least the following components (A) to (C). (A) Polyfunctional urethane-modified (meth)acrylate compound (B) Difunctional (meth)acrylate compounds having a bisphenol skeleton represented by the following general formula (1) (C) A polymer represented by the following general formula (6) having at least one alicyclic skeleton represented by the following structural formulas (2) to (4) and general formula (5).

[0078] [ka]

[0079] [ka] [In the above general formula (1), R1 and R2 each independently represent a hydrogen atom or a methyl group, and m and n represent numerical values.] In the above general formula (5), R is a hydrogen atom, an alkyl group, or a substituted or unsubstituted alkylene group. In the above general formula (6), R1 represents a hydrogen atom or a methyl group, n is 0 or 1, a is a numerical value, and X represents the alicyclic skeleton shown in any of the above structural formulas (2) to (4) and general formula (5). (Configuration 2) The resin composition according to configuration 1, characterized in that it contains component (A) in a proportion of 3 parts by mass or more and 20 parts by mass or less, component (B) in a proportion of 50 parts by mass or more and 80 parts by mass or less, and component (C) in a proportion of 5 parts by mass or more and 30 parts by mass or less.

[0080] (Composition 3) The resin composition according to configuration 1 or 2, characterized in that the aforementioned component (A) is a compound represented by the following general formula (7).

[0081] [ka] [In the above general formula (7), R4 and R5 are each independently hydrogen or a methyl group, R6 and R7 are each independently a hydrocarbon group having 1 to 10 carbon atoms, R8 is an isocyanate residue, R9 is a polyol residue or a polyester residue, and q is 0 or an integer less than or equal to 10.] (Composition 4) The resin composition according to configuration 1 or 2, characterized in that the aforementioned component (A) is a compound represented by the following general formula (8).

[0082] [ka] [In the above general formula (8), R10 R is a hydrocarbon group having 1 to 10 carbon atoms. 11 is a substituent represented by the following general formula (9) or (10).

[0083] [ka] [In the above general formulas (9) and (10), R 13 ,R 14 and R 16 Each is independently either a hydrogen atom or a methyl group, and R 15 This is a hydrocarbon group having 1 to 10 carbon atoms.

[0084] (Composition 5) The resin composition according to any one of configurations 1 to 4, further characterized by containing a polymerizable compound having a polymerizable functional group of a monofunctional (meth)acrylate having at least one of the alicyclic skeletons represented by the above structural formulas (2) to (4) and general formula (5). (Composition 6) A resin composition according to any one of configurations 1 to 5, further characterized by containing a polymerization initiator.

[0085] (Composition 7) An optical element comprising a cured product of a resin composition according to any one of the components 1 to 6, The glass transition temperature of the cured product is 105°C or higher and 160°C or lower. An optical element characterized in that the refractive index of the cured material at the d-line is 1.54 or higher. (Composition 8) The optical element according to configuration 7, further comprising a transparent substrate, wherein the cured product is provided on the transparent substrate. (Composition 9) The transparent substrate has a first surface with a concave spherical shape, The optical element according to configuration 8, wherein the cured material is provided on the first surface. (Composition 10) An optical element according to any one of configurations 7 to 9, wherein the cured product has a water absorption expansion rate of 0.50% or less at 60°C and humidity from 0% to 90%. (Composition 11) The optical element according to any one of configurations 7 to 10, characterized in that the refractive index of the cured material at the d line is 1.58 or less. (Composition 12) The optical element according to any one of configurations 7 to 11, characterized in that the ratio of the maximum thickness d2 to the minimum thickness d1 of the cured material is greater than 1 and 30 or less. (Composition 13) The minimum thickness d1 is 300 μm or less. The optical element according to configuration 12, wherein the maximum thickness d2 is in the range of 10 μm or more and 1000 μm or less.

[0086] (Composition 14) An optical instrument comprising a housing and an optical system having at least one lens disposed within the housing, An optical instrument characterized in that at least one of the lenses is an optical element according to any one of configurations 7 to 13. (Composition 15) An imaging device comprising a housing, an optical system having at least one lens disposed within the housing, and an image sensor that receives light passing through the optical system, An imaging device characterized in that at least one of the lenses is an optical element according to any one of configurations 7 to 13. [Explanation of symbols]

[0087] 1: Transparent substrate, 2: Cured product, 3: Resin composition, 10: Optical element

Claims

1. A resin composition characterized by containing at least the following components (A) to (C). (A) Polyfunctional urethane-modified (meth)acrylate compound (B) Difunctional (meth)acrylate compounds having a bisphenol skeleton represented by the following general formula (1) (C) A polymer represented by the following general formula (6) having at least one of the alicyclic skeletons represented by the following structural formulas (2) to (4) and general formula (5). 【Chemistry 1】 【Chemistry 2】 [In the above general formula (1), R 1 and R 2 Each of these independently represents a hydrogen atom or a methyl group, and m and n represent numerical values. In the above general formula (5), R is a hydrogen atom, an alkyl group, or a substituted or unsubstituted alkylene group. In the above general formula (6), R 1 represents a hydrogen atom or a methyl group, n is 0 or 1, a is a numerical value, and X represents the alicyclic skeleton shown in any of the above structural formulas (2) to (4) and general formula (5).

2. The resin composition according to claim 1, characterized in that it contains component (A) in a proportion of 3 parts by mass or more and 20 parts by mass or less, component (B) in a proportion of 50 parts by mass or more and 80 parts by mass or less, and component (C) in a proportion of 5 parts by mass or more and 30 parts by mass or less.

3. The resin composition according to claim 1, characterized in that the component (A) is a compound represented by the following general formula (7). 【Transformation 3】 〔In the above general formula (7), R 4 and R 5 are each independently hydrogen or a methyl group, R 6 and R 7 are each independently a hydrocarbon group having 1 to 10 carbon atoms, R 8 is an isocyanate residue, R 9 is a polyol residue or a polyester residue, and q is 0 or an integer of 10 or less.〕

4. The resin composition according to claim 1, characterized in that the aforementioned component (A) is a compound represented by the following general formula (8). 【Chemistry 4】 [In the above general formula (8), R 10 R is a hydrocarbon group having 1 to 10 carbon atoms. 11 is a substituent represented by the following general formula (9) or (10). 【Transformation 5】 [In the above general formulas (9) and (10), R 13 , R 14 and R 16 Each is independently either a hydrogen atom or a methyl group, R 15 This is a hydrocarbon group having 1 to 10 carbon atoms.

5. The resin composition according to claim 1, further characterized by containing a polymerizable compound having a polymerizable functional group of a monofunctional (meth)acrylate having at least one of the alicyclic skeletons represented by the above structural formulas (2) to (4) and general formula (5).

6. The resin composition according to claim 1, further characterized by containing a polymerization initiator.

7. An optical element comprising a cured product of the resin composition according to any one of claims 1 to 6, The glass transition temperature of the cured product is 105°C or higher and 160°C or lower. An optical element characterized in that the refractive index of the cured material at the d-line is 1.54 or higher.

8. The optical element according to claim 7, further comprising a transparent substrate, wherein the cured product is provided on the transparent substrate.

9. The transparent substrate has a first surface with a concave spherical shape, The optical element according to claim 8, wherein the cured material is provided on the first surface.

10. The optical element according to claim 7, wherein the cured product has a water absorption expansion rate of 0.50% or less at 60°C and humidity from 0% to 90%.

11. The optical element according to claim 7, characterized in that the refractive index of the cured material at the d line is 1.58 or less.

12. The optical element according to claim 7, characterized in that the ratio of the maximum thickness d2 to the minimum thickness d1 of the cured material is greater than 1 and 30 or less.

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

14. An optical instrument comprising a housing and an optical system having at least one lens disposed within the housing, An optical device characterized in that at least one of the lenses is the optical element described in claim 7.

15. An imaging device comprising a housing, an optical system having at least one lens disposed within the housing, and an image sensor that receives light that has passed through the optical system, An imaging device characterized in that at least one of the lenses is the optical element described in claim 7.

Images