Photocurable resin composition, optical molded body, optical device, and method for manufacturing optical molded body

Abstract

A photocurable resin composition which is a photocurable resin composition that can be used for an optical molded body, an in-plane retardation Re of a cured film produced using the above-described photocurable resin composition under specific conditions, as determined under specific conditions, is 18.0 nm or less.

Description

Technical Field

[0001] This invention relates to photocurable resin compositions, optical molded articles, optical devices, and methods for manufacturing optical molded articles. Background Technology

[0002] In recent years, thermoplastic resins and UV-curable resin compositions have been studied in optical system lenses from the viewpoint of heat resistance and low birefringence. Among these, methacrylic acid-based resin compositions are being investigated as thermoplastic resins. For example, the techniques described in Patent Document 1 and Patent Document 2 can be cited as techniques for methacrylic acid-based resin compositions.

[0003] Patent Document 1 describes a methacrylic resin composition with high heat resistance, highly controlled birefringence, high transmittance over a long optical path, and excellent hue and transparency. The composition comprises a methacrylic resin whose main chain contains at least a structural unit derived from an N-substituted maleimide monomer, has a glass transition temperature exceeding 120°C and below 160°C, a resin temperature of 270°C, and a shear rate of 1000 sec. -1 Under these conditions, the melt viscosity is below 250 Pa·s, and the absolute value of the photoelastic modulus is 1 × 10⁻⁶. -12 pa -1 The transmittance of the solution prepared by dissolving the resin composition in chloroform at a mass-volume percentage of 20% was measured to be 94% or more under conditions of an optical path length of 100 mm and a wavelength of 470 nm, and the transmittance was measured to be 96% or more under conditions of a wavelength of 700 nm.

[0004] Patent Document 2 describes a photocurable composition with the aim of providing a photocurable composition that is fast-curing, non-anaerobic, low-viscosity, low-odor, and has excellent storage stability, and in particular, a photocurable composition that produces a colorless and transparent product with excellent properties required for lenses, such as low optical strain, heat resistance, low water absorption, toughness, and high hardness. The photocurable composition is characterized by containing tricyclodecane skeleton di(meth)acrylate (A), a trifunctional or quadrifunctional secondary thiol (B), a pyrolysis photopolymerization initiator (C), and a hindered phenolic antioxidant (D). The photocurable composition does not contain primary thiol, and the content ratio (by weight) of components (A), (B), (C), and (D) is within the following range.

[0005] Ingredient (A) / Ingredient (B) = 75 / 25 ~ 95 / 5

[0006] Component (C): 2 to 10 parts by weight relative to 100 parts by weight of components (A) and (B) combined.

[0007] Component (D): 0.1 to 1 part by weight relative to 100 parts by weight of components (A) and (B) combined.

[0008] Existing technical documents

[0009] Patent documents

[0010] Patent Document 1: Japanese Patent Application Publication No. 2019-35015

[0011] Patent Document 2: Japanese Patent Application Publication No. 2022-32186 Summary of the Invention

[0012] The problem that the invention aims to solve

[0013] The present invention provides a photocurable resin composition capable of reducing the coloration of optically molded articles.

[0014] Methods for solving problems

[0015] To achieve the aforementioned objectives, the inventors conducted repeated and in-depth research. Their findings revealed a correlation between the in-plane phase difference Re of the photocurable resin composition, measured under specific conditions, and the coloring of the resulting optically molded article. Based on this insight, the inventors further conducted repeated and in-depth research, discovering that by using a photocurable resin composition with an in-plane phase difference Re of 18.0 nm or less, measured under specific conditions, the coloring of the optically molded article can be reduced, thus completing this invention. [1]

[0017] A photocurable resin composition is provided, which is a photocurable resin composition that can be used for optical molding, wherein the in-plane phase difference Re of the cured film prepared using the above-mentioned photocurable resin composition according to the following <curing film preparation conditions> is 18.0 nm or less, as measured according to the following <determination of in-plane phase difference Re>.

[0018] <Conditions for Curing Film Production>

[0019] A 3mm thick, 50mm x 50mm silicone sheet (material: silicone rubber, hardness: 50 degrees) with a 35mm φ circular hole is placed on a 0.7mm thick, 50mm x 50mm alkali-free glass. The aforementioned photocurable resin composition is filled into the circular hole. Then, a 0.7mm thick, 50mm x 50mm alkali-free glass is placed on top of the alkali-free glass. The glass is placed on an SUS laboratory lift platform and the height is adjusted. The photocurable resin composition is irradiated with 405nm LED light at 810mW for 3 minutes from above the alkali-free glass. The glass is then flipped over and irradiated with 405nm LED light at 810mW for 3 minutes. After natural cooling at 23°C for 30 minutes, the cured photocurable resin composition is demolded from the alkali-free glass and the silicone sheet to obtain a cured film of the photocurable resin composition.

[0020] <Determination of in-plane phase difference Re>

[0021] For the above-mentioned cured film, one hour after the LED light irradiation is completed, the in-plane phase difference Re at a distance of 10.0 mm from the center of the above-mentioned cured film is measured using a two-dimensional birefringence evaluation device at an ambient temperature of 23°C and under atmospheric conditions. [2]

[0023] According to the photocurable resin composition described above [1], after the cured film prepared using the photocurable resin composition according to the above <curable film preparation conditions> is subjected to the following <heat treatment>, the in-plane phase difference Re after heating, as measured by the following <determination of in-plane phase difference Re after heat treatment>, is 10.0 nm or less.

[0024] <Heat Treatment>

[0025] The cured film was heated from 23°C to 120°C at a constant rate over 1 hour, heated at 120°C for 1 hour, cooled from 120°C to 23°C at a constant rate over 3 hours, and then exothermized at 23°C for 3 hours.

[0026] <Determination of in-plane phase difference Re after heat treatment>

[0027] For the cured film, one hour after the completion of the above-mentioned heat treatment, the in-plane phase difference Re at a distance of 10.0 mm from the center of the cured film is measured using a two-dimensional birefringence evaluation device at an ambient temperature of 23°C and under atmospheric conditions. [3]

[0029] According to the photocurable resin composition described in [1] or [2] above, the yellowness (YI value) of the cured film prepared using the photocurable resin composition according to the above <curable film preparation conditions> is 6.50 or less when heated at 120°C for 1 hour, as measured according to ASTM E313-73. [4]

[0031] The photocurable resin composition according to any one of [1] to [3] above comprises one or more selected from the group consisting of monofunctional (meth)acrylate monomers and (meth)acrylate monomers with two or more functions. [5]

[0033] According to the photocurable resin composition described above [4], when the total content of the monofunctional (meth)acrylate monomer and the (meth)acrylate monomer with more than two functions is set to 100 parts by mass, the content of the (meth)acrylate monomer with more than two functions is 5.0 parts by mass or more and 90 parts by mass or less. [6]

[0035] According to the photocurable resin composition described in [4] or [5] above, the mass ratio of the content of the monofunctional (meth)acrylate monomer to the content of the (meth)acrylate monomer with more than two functions is 0.50 or more and 10.0 or less. [7]

[0037] The photocurable resin composition according to any one of [4] to [6] above, wherein the monofunctional (meth)acrylate monomer has an alicyclic skeleton. [8]

[0039] The photocurable resin composition according to any one of [4] to [7] above, wherein the (meth)acrylate monomer with more than two functions has an alicyclic skeleton. [9]

[0041] The photocurable resin composition according to any one of [4] to [8] above, wherein the above-mentioned (meth)acrylate monomer with more than two functions has a straight-chain hydrocarbon backbone.

[10]

[0043] The photocurable resin composition according to any one of [1] to [9] above further comprises an antioxidant.

[11]

[0045] The photocurable resin composition according to any one of [1] to

[10] above further comprises a photopolymerization initiator.

[12]

[0047] According to the photocurable resin composition described above

[11] , wherein the photopolymerization initiator comprises a photoradical polymerization initiator.

[13]

[0049] The photocurable resin composition according to any one of [1] to

[12] above further comprises a light stabilizer.

[14]

[0051] The photocurable resin composition according to any one of [1] to

[13] above can be used in casting.

[15]

[0053] The photocurable resin composition according to any one of [1] to

[14] above can be used for one or more lenses selected from the group consisting of lenses for virtual reality devices (VR lenses), lenses for mixed reality devices (MR lenses), lenses for augmented reality devices (AR lenses), lenses for extended reality devices (xR lenses), and lenses for head-mounted displays (HMD lenses).

[16]

[0055] An optical molding body comprising a cured product of the photocurable resin composition described in any one of [1] to

[15] above.

[17]

[0057] According to the optical molding body described above

[16] , wherein the optical molding body includes a lens.

[18]

[0059] According to the optical shaping body described above

[17] , the lens includes one or more of the following: a lens for virtual reality devices (VR lens), a lens for mixed reality devices (MR lens), a lens for augmented reality devices (AR lens), a lens for extended reality devices (xR lens), and a lens for head-mounted displays (HMD lens).

[19]

[0061] The optical molding body according to any one of

[16] to

[18] above, wherein the maximum thickness portion is 20.0 mm or less.

[20]

[0063] The optical molding body according to any one of

[16] to

[19] above, wherein the maximum thickness portion is 1.0 mm or more. [twenty one]

[0065] An optical device comprising the optical molding body described in any one of

[16] to

[20] above. [twenty two]

[0067] A method for manufacturing an optical molded body includes: a curing step, wherein the optical molded body is cured by irradiating the photocurable resin composition described in any one of [1] to

[15] with light; and a heating step, wherein the optical molded body is heated to reduce the coloring of the optical molded body. [twenty three]

[0069] According to the manufacturing method of the optical molded body described above

[22] , the heating temperature for heating the optical molded body in the heating process is 80°C or higher.

[0070] Invention Effects

[0071] According to the present invention, a photocurable resin composition capable of reducing the coloration of optically molded articles can be provided. Detailed Implementation

[0072] The term "(meth)acrylate" in this specification includes both acrylate and methacrylate. The same applies to terms such as "(meth)acryloyl" and similar expressions.

[0073] For each component in this embodiment, one type can be used, or two or more types can be used in combination. In addition, the "~" symbol indicating the numerical range means above and below, including both the upper and lower limits.

[0074] (Photocurable resin composition)

[0075] In this embodiment, the photocurable resin composition (hereinafter also appropriately referred to as "resin composition") is a photocurable resin composition that can be used in optically molded articles.

[0076] In the photocurable resin composition of this embodiment, the in-plane phase difference Re of the cured film prepared using the photocurable resin composition according to the following <curing film preparation conditions> is 18.0 nm or less, as measured according to the following <determination of in-plane phase difference Re>.

[0077] <Conditions for Curing Film Production>

[0078] A 3mm thick, 50mm x 50mm silicone sheet (material: silicone rubber, hardness: 50 degrees) with a 35mm φ circular hole is placed on a 0.7mm thick, 50mm x 50mm alkali-free glass substrate. The aforementioned photocurable resin composition is filled into the circular hole. Another 0.7mm thick, 50mm x 50mm alkali-free glass substrate is then placed on top. The substrate is placed on an SUS-made laboratory lift platform with its height adjusted. The photocurable resin composition is irradiated with 405nm LED light at 810mW for 3 minutes from above the alkali-free glass. The substrate is then flipped, and irradiation with 405nm LED light at 810mW for another 3 minutes is performed. After irradiation with LED light, the substrate is allowed to cool naturally at 23°C for 30 minutes. The cured photocurable resin composition is then demolded from the alkali-free glass and the silicone sheet to obtain a cured film of the aforementioned photocurable resin composition.

[0079] <Determination of in-plane phase difference Re>

[0080] For the cured film, one hour after the LED light irradiation is completed, the in-plane phase difference Re at a distance of 10.0 mm from the center of the cured film is measured using a two-dimensional birefringence evaluation device at an ambient temperature of 23°C and atmospheric conditions.

[0081] The photocurable resin composition of this embodiment, by having the structure described above, can reduce the coloration of optically molded articles.

[0082] The photocurable resin composition may contain, for example, a polymeric compound. From the viewpoint of further reducing the coloration of the optically molded article, the polymeric compound preferably contains a (meth)acrylate monomer (A).

[0083] The properties of the photocurable resin composition are not particularly limited. However, from the viewpoint of being suitable for forming optically molded articles by injection molding or casting molding, the photocurable resin composition is preferably in liquid form.

[0084] Furthermore, from the viewpoint of increasing the design freedom of optically molded bodies, photocurable resin compositions are preferably used for molding using casting methods.

[0085] Next, specific examples will be given to illustrate the composition of the photocurable resin composition.

[0086] It should be noted that the photocurable resin composition may consist of a polymeric compound or contain components other than polymeric compounds. Specific examples of other components may include one or more selected from the group consisting of antioxidants (B), photopolymerization initiators (C), and light stabilizers (D) as described below.

[0087] <Polymerizing compounds>

[0088] The polymerizable compound can be any compound having a polymerizable functional group, and preferably a compound having a free radical polymerizable functional group. From the viewpoint of further reducing the coloration of the optically molded body, an example of a free radical polymerizable functional group is (meth)acryloyl. From the viewpoint of further reducing the coloration of the optically molded body, the polymerizable compound preferably contains a (meth)acrylate monomer (A).

[0089] <(Meth)acrylate monomer (A)>

[0090] (Meth)acrylate monomer (A) is a compound having a (meth)acryloyl group. (Meth)acrylate monomer (A) is a molecule that can bond with other molecules through free radical polymerization via the (meth)acryloyl group.

[0091] From the viewpoint of further reducing the coloring of optically molded articles, the (meth)acrylate monomer (A) preferably includes one or more selected from the group consisting of monofunctional (meth)acrylate monomers (A1) and (meth)acrylate monomers (A2) with two or more functions.

[0092] Regarding the content of the (meth)acrylate monomer (A2) with two or more functionalities in the photocurable resin composition of this embodiment, from the viewpoint of improving the crack resistance during the molding of the optical molded article and from the viewpoint of further reducing the coloring of the optical molded article, when the total content of the monofunctional (meth)acrylate monomer (A1) and the (meth)acrylate monomer (A2) with two or more functionalities is set to 100 parts by mass, it is preferably 5.0 parts by mass or more and 90 parts by mass or less, more preferably 10 parts by mass or more and 70 parts by mass or less, even more preferably 12 parts by mass or more and 50 parts by mass or less, even more preferably 15 parts by mass or more and 40 parts by mass or less, and even more preferably 18 parts by mass or more and 35 parts by mass or less.

[0093] From the viewpoint of further reducing the coloration of the optically molded body, the mass ratio of the content of monofunctional (meth)acrylate monomer (A1) in the photocurable resin composition of this embodiment to the content of difunctional or more (meth)acrylate monomer (A2) is preferably 0.50 or more and 10.0 or less, more preferably 1.00 or more and 8.00 or less, even more preferably 1.50 or more and 6.00 or less, even more preferably 1.80 or more and 5.00 or less, and even more preferably 2.00 or more and 4.50 or less.

[0094] <Monofunctional (meth)acrylate monomer (A1)>

[0095] Monofunctional (meth)acrylate monomers (A1) include, for example, one or more of the following groups: aromatic ring monofunctional (meth)acrylates; alicyclic monofunctional (meth)acrylates; linear monofunctional (meth)acrylates (e.g., monofunctional (meth)acrylate monomers having a linear hydrocarbon skeleton); branched monofunctional (meth)acrylates; and chain monofunctional (meth)acrylates.

[0096] The monofunctional (meth)acrylate monomer (A1) preferably comprises selected from isobornyl (meth)acrylate, dicyclopentyl (meth)acrylate (e.g., GM81HDA, manufactured by Kokusei Chemical Co., Ltd.), 3,3,5-trimethylcyclohexyl (meth)acrylate, 4-tert-butylcyclohexyl (meth)acrylate, dicyclopentenyl (meth)acrylate (e.g., FA-511AS, manufactured by Hitachi Chemical Co., Ltd.), dicyclopentenoxyethyl (meth)acrylate, tetrahydrofurfuryl (meth)acrylate, 2-hydroxyethyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, isobutyl (meth)acrylate, tert-butyl (meth)acrylate, isooctyl (meth)acrylate, 2-methoxyethyl (meth)acrylate, and methoxytriethylene glycol. (Meth)acrylate, 2-ethoxyethyl (meth)acrylate, 3-methoxybutyl (meth)acrylate, ethoxyethyl (meth)acrylate, butoxyethyl (meth)acrylate, ethoxydiethylene glycol (meth)acrylate, methoxydihexyl ethyl (meth)acrylate, ethyl diethylene glycol (meth)acrylate, cyclic trimethylolpropane methyl acetal mono(meth)acrylate, imide (meth)acrylate, isoamyl (meth)acrylate, ethoxylated succinic acid (meth)acrylate, trifluoroethyl (meth)acrylate, ω-carboxylated polycaprolactone mono(meth)acrylate, cyclohexyl (meth)acrylate, 2-(2-ethoxyethoxy)ethyl (meth)acrylate, stearate (meth)acrylate, (meth)acrylate Isostearyl acrylate (e.g., S-1800A, manufactured by Shin-Nakamura Chemical Industry Co., Ltd.), diethylene glycol monobutyl ether (meth)acrylate, lauryl acrylate (e.g., LA, manufactured by Osaka Organic Chemical Industry Co., Ltd.), isodecyl acrylate (meth)acrylate, octyl / decyl acrylate (meth)acrylate, tridecyl acrylate (meth)acrylate, caprolactone (meth)acrylate, ethoxylated (4)nonylphenol (meth)acrylate, methoxy polyethylene glycol (350) mono(meth)acrylate, methoxy polyethylene glycol (550) mono(meth)acrylate, phenoxyethyl acrylate (meth)acrylate, benzyl acrylate (meth)acrylate, methylphenoxyethyl acrylate (meth)acrylate, caprolactone-modified tetrahydrofurfuryl acrylate (meth)acrylate, (meth)propyl The group consisting of one or more of the following: tribromophenyl acrylate, ethoxylated tribromophenyl acrylate, 2-phenoxyethyl acrylate, ethylene oxide adduct of 2-phenoxyethyl acrylate, propylene oxide adduct of 2-phenoxyethyl acrylate, phenoxydiethylene glycol (meth)acrylate, 2-hydroxy-3-phenoxypropyl acrylate, 3-methacryloyloxymethylcyclohexene oxide, 3-(methacryloyloxymethylcyclohexene oxide), ethoxylated o-phenylphenol (meth)acrylate (e.g., A-LEN-10, manufactured by Shin-Nakamura Chemical Industry Co., Ltd.), 2-methacryloyloxy-2-methyladamantane, and 2-methacryloyloxy-2-ethyladamantane.

[0097] From the viewpoint of being able to further reduce the coloration of optically molded articles, the monofunctional (meth)acrylate monomer (A1) is more preferably one or more selected from the group consisting of lauryl (meth)acrylate and dicyclopentyl (meth)acrylate.

[0098] From the viewpoint of further reducing the coloring of optically molded articles, the monofunctional (meth)acrylate monomer (A1) preferably has an alicyclic backbone. From the viewpoint of further reducing the coloring of optically molded articles, the monofunctional (meth)acrylate monomer (A1) more preferably contains dicyclopentyl (meth)acrylate, and even more preferably contains dicyclopentyl methacrylate.

[0099] <2 or more functional (meth)acrylate monomers (A2)>

[0100] The (meth)acrylate monomer (A2) with two or more functions preferably includes one or more selected from the group consisting of alicyclic difunctional (meth)acrylate monomers and linear difunctional (meth)acrylate monomers.

[0101] Alicyclic difunctional (meth)acrylate monomers are difunctional (meth)acrylate monomers with an alicyclic hydrocarbon structure in their molecular structure. From the viewpoint of improving heat resistance, the number of carbon atoms in the alicyclic hydrocarbon structure is preferably 4 or more and 14 or less, more preferably 5 or more and 12 or less, and even more preferably 6 or more and 10 or less.

[0102] Alicyclic hydrocarbon structures can be either saturated or unsaturated. From the perspective of improving heat resistance, saturated hydrocarbon structures are preferred for alicyclic hydrocarbon structures.

[0103] Furthermore, the alicyclic hydrocarbon structure can be a monocyclic hydrocarbon structure, a fused-ring hydrocarbon structure, or a bridged-ring hydrocarbon structure. Alicyclic difunctional (meth)acrylate monomers can contain groups with these alicyclic hydrocarbon structures in their molecular structure, preferably containing divalent groups with alicyclic hydrocarbon structures.

[0104] Specific examples of monocyclic hydrocarbon groups include groups with cyclohexylene and cyclohexyl groups that have cycloalkane structures; and groups with cyclodectrienyl and cyclodectrienyl groups that have cycloolefin skeletons.

[0105] Specific examples of polycyclic hydrocarbon groups include tricyclodecanediyl, dicyclopentyl, and dicyclopentenyl groups that have a dicyclopentadiene skeleton; norbornanediyl, isobornanediyl, norbornyl, and isobornyl groups that have a norbornane skeleton; and adamantanediyl and adamantanealkyl groups that have an adamantane skeleton.

[0106] From the viewpoint of further reducing the coloring of optically molded parts, the cyclic hydrocarbon group in the alicyclic difunctional (meth)acrylate monomer is preferably a group having a dicyclopentadiene backbone.

[0107] Furthermore, from the viewpoint of reducing curing shrinkage during the molding of optically molded articles, the alicyclic difunctional (meth)acrylate monomer preferably includes tricyclodecanediethanol di(meth)acrylate, more preferably tricyclodecanediethanol di(meth)acrylate, and even more preferably tricyclodecanediethanol dimethacrylate (e.g., DCP, manufactured by Shin-Nakamura Chemical Industry Co., Ltd.).

[0108] Linear difunctional (meth)acrylate monomers are (meth)acrylates that have a linear structure in their molecular structure and have two (meth)acryloyl groups.

[0109] From the viewpoint of improving crack resistance during the molding of optical molded articles, the linear structure preferably includes divalent linear hydrocarbon groups. From the viewpoint of reducing liquid volume deviations caused by monomer volatilization during the molding of optical molded articles, the number of carbon atoms in the divalent linear hydrocarbon groups is, for example, 1 or more, preferably 2 or more, and more preferably 4 or more. Furthermore, from the viewpoint of improving heat resistance, the number of carbon atoms in the divalent linear hydrocarbon groups is preferably 20 or less, and more preferably 14 or less.

[0110] As a specific example of a linear difunctional (meth)acrylate monomer, di(meth)acrylate of an alkanediol can be cited.

[0111] The linear difunctional (meth)acrylate monomer preferably comprises selected from 1,6-hexanediol di(meth)acrylate (e.g., A-HD-N, manufactured by Shin-Nakamura Chemical Industry Co., Ltd.; HD-N, manufactured by Shin-Nakamura Chemical Industry Co., Ltd.), 1,9-nonanediol di(meth)acrylate (e.g., A-NOD-N, manufactured by Shin-Nakamura Chemical Industry Co., Ltd.; LIGHT ACRYLATE 1,9ND-A, manufactured by Kyoeisha Chemical Co., Ltd.; NOD-N, manufactured by Shin-Nakamura Chemical Industry Co., Ltd.; LIGHT ACRYLATE The group consisting of one or more of the following: 1,9-ND-M (manufactured by Kyoeisha Chemical Co., Ltd.); 1,10-decanediol di(meth)acrylate (e.g., A-DOD-N, manufactured by Shin-Nakamura Chemical Industry Co., Ltd.; DOD-N, manufactured by Shin-Nakamura Chemical Industry Co., Ltd.); 1,12-dodecanediol di(meth)acrylate (e.g., DDD, manufactured by Shin-Nakamura Chemical Industry Co., Ltd.; SR262, manufactured by Arkema Co., Ltd.); ethylene glycol di(meth)acrylate (e.g., SR206NS, manufactured by Arkema Co., Ltd.); triethylene glycol di(meth)acrylate (e.g., SR272, manufactured by Arkema Co., Ltd.); polyethylene glycol di(meth)acrylate (e.g., A-400, manufactured by Shin-Nakamura Chemical Industry Co., Ltd.); 1,3-butanediol di(meth)acrylate (e.g., BG, manufactured by Shin-Nakamura Chemical Industry Co., Ltd.); and 1,4-butanediol di(meth)acrylate (e.g., BD, manufactured by Shin-Nakamura Chemical Industry Co., Ltd.).

[0112] From the viewpoint of reducing cracks generated in optically molded articles, linear difunctional (meth)acrylate monomers more preferably include one or more (meth)acrylates selected from the group consisting of 1,12-dodecanediol di(meth)acrylate and 1,9-nonanediol di(meth)acrylate.

[0113] From the viewpoint of further reducing the coloring of optically molded articles, the (meth)acrylate monomer (A2) with two or more functionalities preferably has an alicyclic backbone. From the viewpoint of further reducing the coloring of optically molded articles, the (meth)acrylate monomer (A2) with two or more functionalities more preferably contains tricyclodecanediethanol di(meth)acrylate, and even more preferably contains tricyclodecanediethanol dimethacrylate.

[0114] From the viewpoint of further reducing the coloring of optically molded articles, the (meth)acrylate monomer (A2) with more than two functionalities preferably has a straight-chain hydrocarbon backbone. From the viewpoint of further reducing the coloring of optically molded articles, the (meth)acrylate monomer (A2) with more than two functionalities more preferably contains 1,12-dodecanediol di(meth)acrylate, and even more preferably contains 1,12-dodecanediol dimethacrylate.

[0115] <Antioxidant (B)>

[0116] The photocurable resin composition of this embodiment may further include an antioxidant (B). There are no particular limitations on the antioxidant (B), and known antioxidants may be used. The antioxidant (B) may, for example, include one or more selected from the group consisting of phenolic antioxidants, phosphorus antioxidants, sulfur-based antioxidants, hindered amine antioxidants, and thioether antioxidants.

[0117] Examples of phenolic antioxidants include 2,6-di-tert-butylhydroxytoluene and pentaerythritol tetrakis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate].

[0118] Commercially available phenolic antioxidants include, for example, ADK STAB series products manufactured by ADEKA Co., Ltd., such as AO-20, AO-30, AO-40, AO-50, AO-60 and AO-80.

[0119] Examples of phosphorus-based antioxidants include phosphines such as trialkylphosphine and triarylphosphine, as well as trialkyl phosphites and triaryl phosphites.

[0120] Commercially available phosphorus-based antioxidants include, for example, the ADK STAB series manufactured by ADEKA Co., Ltd., such as PEP-4C, PEP-8, PEP-24G, PEP-36, HP-10, 260, 522A, 329K, 1178, 1500, 135A and 3010.

[0121] Examples of sulfur-based antioxidants include dilaurate 3,3-thiodipropionate, dimyristyl 3,3'-thiodipropionate, distearate 3,3-thiodipropionate, lauryl stearate 3,3-thiodipropionate, pentaerythritol tetra(β-lauryl thiopropionate), and 3,9-bis(2-dodecylthioethyl)-2,4,8,10-tetraoxaspiro[5,5]undecane.

[0122] Examples of hindered amine antioxidants include bis(1,2,2,6,6-pentamethyl-4-piperidinyl) sebacate, methyl(1,2,2,6,6-pentamethyl-4-piperidinyl) sebacate, 2,4-bis[N-butyl-N-(1-cyclohexyloxy-2,2,6,6-tetramethylpiperidin-4-yl)amino]-6-(2-hydroxyethylamine)-1,3,5-triazine, bis(2,2,6,6-tetramethyl-1-(octoxy)-4-piperidin) sebacate, and bis(1,2,2,6,6-pentamethyl-4-piperidin) sebacate.

[0123] Commercially available hindered amine antioxidants include, for example, AL-72 from the ADK STAB series manufactured by ADEKA Corporation, and hindered amine antioxidants from the TINUVIN series manufactured by BASF, such as 111FDL, 123, 144, 152, 292 and 5100.

[0124] Examples of thioether-based antioxidants include bis(tetranyl) 3,3'-thiodipropionate and bis[3-(dodecylthio)propionate]2,2-bis[[3-(dodecylthio)-1-oxopropoxy]methyl]-1,3-propanediyl ester.

[0125] Commercially available thioether-based antioxidants include, for example, ADK STAB series products manufactured by ADEKA Co., Ltd., such as AO-26, AO-412S, and AO-503A.

[0126] From the viewpoint of further reducing the coloration of optically molded bodies, antioxidant (B) preferably includes one or more of the group consisting of phenolic antioxidants and thioether antioxidants. From the viewpoint of further reducing the coloration of optically molded bodies, antioxidant (B) is more preferably included in the group consisting of one or more of the group consisting of bis[3-(dodecylthio)propionic acid]2,2-bis[[3-(dodecylthio)-1-oxopropoxy]methyl]-1,3-propanediyl ester (e.g., ADK STAB AO-412S, manufactured by ADEKA Co., Ltd.) and pentaerythritol tetra[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate] (e.g., ADK STABAO-60, manufactured by ADEKA Co., Ltd.).

[0127] From the viewpoint of further reducing the coloration of the optically molded body, the content of antioxidant (B) in the photocurable resin composition of this embodiment is preferably 0.010 parts by mass or more and 10 parts by mass or less relative to 100 parts by mass of (meth)acrylate monomer (A), more preferably 0.050 parts by mass or more and 5.0 parts by mass or less, even more preferably 0.10 parts by mass or more and 3.0 parts by mass or less, even more preferably 0.20 parts by mass or more and 2.0 parts by mass or less, and even more preferably 0.50 parts by mass or more and 1.5 parts by mass or less.

[0128] Regarding the content of antioxidant (B) in the photocurable resin composition of this embodiment, when the total amount of solid components in the photocurable resin composition (the total amount of components remaining as solid matter when the cured product is made) is set to 100% by mass, from the viewpoint of further reducing the coloration of the optically molded article, it is preferably 0.010% by mass or more and 5.0% by mass or less, more preferably 0.050% by mass or more and 4.0% by mass or less, even more preferably 0.10% by mass or more and 3.0% by mass or less, even more preferably 0.50% by mass or more and 2.0% by mass or less, and even more preferably 0.90% by mass or more and 1.0% by mass or less.

[0129] <Photopolymerization Initiator (C)>

[0130] The photocurable resin composition of this embodiment may further include a photopolymerization initiator (C). There are no particular limitations on the photopolymerization initiator (C), and any known polymerization initiator may be used.

[0131] From the viewpoint of stably forming optically shaped bodies at low temperatures, the photopolymerization initiator (C) preferably comprises a photoradical polymerization initiator. A photoradical polymerization initiator is a compound that generates free radicals by irradiation with ultraviolet or visible light.

[0132] Examples of photoradical polymerization initiators include acylphosphine oxide initiators, oxyphenyl acetate initiators, benzoylformic acid initiators, and hydroxyphenyl ketone initiators.

[0133] Examples of photopolymerization initiators (C) include benzophenone, miconazole, 4,4'-bis(diethylamino)benzophenone, xanthonesone, thioxanthonesone, isopropyl xanthonesone, 2,4-diethylthioxanthonesone, 2-ethylanthraquinone, acetophenone, 2-hydroxy-2-methyl-4'-isopropylphenylacetone, isopropyl benzoin ether, isobutyl benzoin ether, 2,2-diethoxyacetophenone, 2,2-dimethoxy-2-phenylacetophenone, camphorquinone, benzoanthrone, ethyl 4-dimethylaminobenzoate, isoamyl 4-dimethylaminobenzoate, 4,4'-bis(tert-butylperoxycarbonyl)benzophenone, 3,4,4'-tris(tert-butylperoxycarbonyl)benzophenone, and 3,3',4,4'-tetra(tert-butylperoxycarbonyl)benzophenone. 3,3',4,4'-Tetra(tert-hexylperoxycarbonyl)benzophenone, 3,3'-Di(methoxycarbonyl)-4,4'-Di(tert-butylperoxycarbonyl)benzophenone, 3,4'-Di(methoxycarbonyl)-4,3'-Di(tert-butylperoxycarbonyl)benzophenone, 4,4'-Di(methoxycarbonyl)-3,3'-Di(tert-butylperoxycarbonyl)benzophenone, 2-(4'-methoxystyryl)-4,6-bis(trichloromethyl)triazine, 2-(3',4'-dimethoxystyryl)-4,6-bis(trichloromethyl)triazine, 2-(2',4'-dimethoxystyryl)-4,6-bis(trichloromethyl)triazine, 2-(2'-methoxyphenyl) Vinyl)-4,6-bis(trichloromethyl)triazine, 2-(4'-pentoxystyryl)-4,6-bis(trichloromethyl)triazine, 4-[p-N,N-di(ethoxycarbonylmethyl)]-2,6-bis(trichloromethyl)triazine, 1,3-bis(trichloromethyl)-5-(2'-chlorophenyl)triazine, 1,3-bis(trichloromethyl)-5-(4'-methoxyphenyl)triazine, 2-(p-dimethylaminostyryl)benzoxazole, 2-(p-dimethylaminostyryl)benzothiazole, 2-mercaptobenzothiazole, 3,3'-carbonylbis(7-diethylaminocoumarin), 2-(o-chlorophenyl)-4,4',5,5'-tetraphenyl-1,2'-biimidazole, 2, 2'-Bis(2-chlorophenyl)-4,4',5,5'-tetra(4-ethoxycarbonylphenyl)-1,2'-biimidazole, 2,2'-bis(2,4-dichlorophenyl)-4,4',5,5'-tetraphenyl-1,2'-biimidazole, 2,2'-bis(2,4-dibromophenyl)-4,4',5,5'-tetraphenyl-1,2'-biimidazole, 2,2'-bis(2,4,6-trichlorophenyl)-4,4',5,5'-tetraphenyl-1,2'-biimidazole, 3-(2-methyl-2-dimethylaminopropionyl)carbazole, 3,6-bis(2-methyl-2-morpholinopropionyl)-9-n-dodecylcarbazole, bis(η5-2,4-cyclopentadien-1-yl)-bis(2,6-Difluoro-3-(1H-pyrrolo-1-yl)phenyl)titanium, 1-hydroxycyclohexylphenyl ketone, 2-hydroxy-2-methyl-1-phenyl-1-propanone, 1-[4-(2-hydroxyethoxy)phenyl]-2-hydroxy-2-methyl-1-propanone, 2-hydroxy-1-{4-[4-(2-hydroxy-2-methylpropionyl)benzyl]phenyl}-2-methyl-1-propanone, 2-methyl-1-[4-(methylthio)phenyl]-2-morpholino-1-propanone, 2-(dimethylamino)-1-(4-morpholinophenyl)-2-benzyl-1-butanone, 2-(dimethylamino)-2-[(4-methylphenyl)methyl]- 1-[4-(4-morpholinyl)phenyl]-1-butanone, 2-[2-oxo-2-phenylacetoxyethoxy]ethyl oxyphenylacetate, 2-[2-hydroxyethoxy]ethyl oxyphenylacetate, methyl benzoylformate, bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide, 2,4,6-trimethylbenzoyl diphenylphosphine oxide, 2,4,6-trimethylbenzoyl diphenylphosphine ester, 1-[4-(phenylthio)phenyl]-1,2-octanedione 2-(O-benzoyl oxime), 1-[9-ethyl-6-(2-methylbenzoyl)-9H-carbazole-3-yl]-acetone-1-(O-acetyl oxime), etc.

[0134] From the viewpoint of further reducing the coloration of the optically molded body, the photopolymerization initiator (C) preferably contains a hydroxyphenyl ketone initiator, more preferably 1-hydroxycyclohexylphenyl ketone (e.g., Omnirad 184, manufactured by IGM Resins).

[0135] From the viewpoint of improving the curability of the photocurable resin composition, the content of photopolymerization initiator (C) in the photocurable resin composition of this embodiment is preferably 0.10 parts by mass or more, more preferably 0.50 parts by mass or more, even more preferably 1.0 parts by mass or more, even more preferably 2.0 parts by mass or more, and even more preferably 3.0 parts by mass or more, relative to 100 parts by mass of (meth)acrylate monomer (A).

[0136] From the viewpoint of improving the uniformity of the thickness of the photocurable resin composition during curing, the content of photopolymerization initiator (C) in the photocurable resin composition of this embodiment is preferably 10 parts by mass or less, more preferably 8.0 parts by mass or less, even more preferably 6.0 parts by mass or less, even more preferably 5.0 parts by mass or less, and even more preferably 4.5 parts by mass or less, relative to 100 parts by mass of (meth)acrylate monomer (A).

[0137] From the viewpoints of improving the curability of the photocurable resin composition and improving the uniformity of the thickness of the photocurable resin composition during curing, the content of photopolymerization initiator (C) in the photocurable resin composition of this embodiment is preferably 0.10 parts by mass or more and 10 parts by mass or less relative to 100 parts by mass of (meth)acrylate monomer (A), more preferably 0.50 parts by mass or more and 8.0 parts by mass or less, further preferably 1.0 parts by mass or more and 6.0 parts by mass or less, further preferably 2.0 parts by mass or more and 5.0 parts by mass or less, and further preferably 3.0 parts by mass or more and 4.5 parts by mass or less.

[0138] Regarding the content of photopolymerization initiator (C) in the photocurable resin composition of this embodiment, when the total amount of solid components in the photocurable resin composition (the total amount of components remaining as solid substances when the cured product is made) is set to 100% by mass, from the viewpoint of further reducing the coloration of the optically molded article, it is preferably 0.10% by mass or more and 10% by mass or less, more preferably 1.0% by mass or more and 8.0% by mass or less, even more preferably 2.0% by mass or more and 6.0% by mass or less, even more preferably 3.0% by mass or more and 5.0% by mass or less, and even more preferably 3.5% by mass or more and 4.0% by mass or less.

[0139] <Light Stabilizer (D)>

[0140] The photocurable resin composition of this embodiment may further include a light stabilizer (D). There are no particular limitations on the light stabilizer (D), and known light stabilizers can be used. By including the light stabilizer (D), the photocurable resin composition can improve its colorfastness.

[0141] From the viewpoint of further improving colorfastness, the light stabilizer (D) preferably contains a hindered amine light stabilizer.

[0142] Examples of hindered amine-based light stabilizers include (1,2,2,6,6-pentamethylpiperidin-4-yl) methacrylate, bis(2,2,6,6-tetramethyl-1-(octoxy)-4-piperidinyl) sebacate, a substance consisting of 70% by mass of the reaction product of 1,1-dimethylethyl hydroperoxide and octane and 30% by mass of polypropylene, bis(1,2,2,6,6-pentamethyl-4-piperidinyl)[[3,5-bis(1,1-dimethylethyl)-4-hydroxyphenyl]methyl]butylmalonate, and bis(1,2,2,6,6-pentamethyl-4-piperidinyl) sebacate and methyl-1,2,2,6,6-pentamethyl Mixtures of 4-piperidinyl sebacate, bis(2,2,6,6-tetramethyl-4-piperidinyl) sebacate, tetra(2,2,6,6-tetramethyl-4-piperidin) ester of 1,2,3,4-butanetetracarboxylate, tetra(1,2,2,6,6-pentamethyl-4-piperidin) ester of 1,2,3,4-butanetetracarboxylate, mixtures of 2,2,6,6-tetramethyl-4-piperidin ester of 1,2,3,4-butanetetracarboxylate and tridecyl ester of 1,2,3,4-butanetetracarboxylate, mixtures of 1,2,2,6,6-pentamethyl-4-piperidin ester of 1,2,3,4-butanetetracarboxylate and tridecyl ester of 1,2,3,4-butanetetracarboxylate, etc.

[0143] From the viewpoint of further improving colorfastness, the light stabilizer (D) preferably contains 1,2,2,6,6-pentamethyl-4-piperidinium methacrylate (e.g., ADK STAB LA-82, manufactured by ADEKA Co., Ltd.).

[0144] Regarding the content of light stabilizer (D) in the photocurable resin composition of this embodiment, when the total amount of solid components in the photocurable resin composition (the total amount of components remaining as solid substances when the cured product is made) is set to 100% by mass, from the viewpoint of further reducing the coloration of the optically molded article, it is preferably 0.0010% by mass or more, more preferably 0.0050% by mass or more, even more preferably 0.010% by mass or more, even more preferably 0.050% by mass or more, and even more preferably 0.090% by mass or more.

[0145] Regarding the content of light stabilizer (D) in the photocurable resin composition of this embodiment, when the total amount of solid components in the photocurable resin composition (the total amount of components that remain as solid substances when the cured product is made) is set to 100% by mass, from the viewpoint of reducing exudation, it is preferably 1.00% by mass or less, more preferably 0.60% by mass or less, even more preferably 0.50% by mass or less, even more preferably 0.40% by mass or less, and even more preferably 0.30% by mass or less.

[0146] From the viewpoints of further reducing the coloration of the optically molded body and reducing exudation, when the total amount of solid components in the photocurable resin composition (the total amount of components remaining as solid matter when the cured product is made) is set to 100% by mass, the content of light stabilizer (D) in the photocurable resin composition of this embodiment is preferably 0.0010% by mass or more and 1.00% by mass or less, more preferably 0.0050% by mass or more and 0.60% by mass or less, even more preferably 0.010% by mass or more and 0.50% by mass or less, even more preferably 0.050% by mass or more and 0.40% by mass or less, and even more preferably 0.090% by mass or more and 0.30% by mass or less.

[0147] <Other Ingredients>

[0148] The photocurable resin composition may include one or more selected from the group consisting of fillers, curing accelerators, plasticizers, heat stabilizers, flame retardants, antistatic agents, defoamers, silane coupling agents, ultraviolet absorbers, surfactants, and leveling agents as specific examples of other components besides polymerizable compounds (e.g., (meth)acrylate monomers (A)), antioxidants (B), photopolymerization initiators (C), and light stabilizers (D).

[0149] <Method for manufacturing photocurable resin compositions>

[0150] The photocurable resin composition of this embodiment can be obtained by mixing a polymeric compound (e.g., (meth)acrylate monomer (A)) with other components such as an antioxidant (B), a photopolymerization initiator (C), or a light stabilizer (D) as needed, using conventionally known methods.

[0151] <Physical Properties of Photocurable Resin Compositions>

[0152] Next, the physical properties of the photocurable resin composition will be described.

[0153] The in-plane phase difference Re, measured according to the following <Measurement of In-Plane Phase Difference Re>, is described for the cured film prepared using the photocurable resin composition of this embodiment according to the <Curing Film Preparation Conditions> below.

[0154] From the viewpoint of further reducing the coloration of the optically molded body, the in-plane phase difference Re of the photocurable resin composition of this embodiment is preferably 18.0 nm or less, more preferably 17.0 nm or less, even more preferably 15.0 nm or less, even more preferably 13.0 nm or less, even more preferably 12.0 nm or less, even more preferably 10.0 nm or less, even more preferably 8.0 nm or less, even more preferably 7.0 nm or less, even more preferably 5.0 nm or less.

[0155] The lower limit of the in-plane phase difference Re of the photocurable resin composition in this embodiment is not particularly limited. For example, it can be 0.0 nm or more, 0.1 nm or more, 0.5 nm or more, 1.0 nm or more, 2.0 nm or more, or 3.0 nm or more.

[0156] From the viewpoint of further reducing the coloration of the optically molded body, the in-plane phase difference Re of the photocurable resin composition of this embodiment is preferably 0.0 nm or more and 18.0 nm or less, more preferably 0.0 nm or more and 17.0 nm or less, even more preferably 0.0 nm or more and 15.0 nm or less, even more preferably 0.0 nm or more and 13.0 nm or less, even more preferably 0.0 nm or more and 12.0 nm or less, even more preferably 0.0 nm or more and 10.0 nm or less, even more preferably 0.0 nm or more and 8.0 nm or less, even more preferably 0.0 nm or more and 7.0 nm or less, even more preferably 0.0 nm or more and 5.0 nm or less.

[0157] <Conditions for Curing Film Production>

[0158] A 3mm thick, 50mm x 50mm silicone sheet (material: silicone rubber, hardness: 50 degrees) with a 35mm φ circular hole is placed on a 0.7mm thick, 50mm x 50mm alkali-free glass substrate. The aforementioned photocurable resin composition is filled into the circular hole. Another 0.7mm thick, 50mm x 50mm alkali-free glass substrate is then placed on top. The substrate is placed on an SUS-made laboratory lift platform with its height adjusted. The photocurable resin composition is irradiated with 405nm LED light at 810mW for 3 minutes from above the alkali-free glass. The substrate is then flipped, and irradiation with 405nm LED light at 810mW for another 3 minutes is performed. After irradiation with LED light, the substrate is allowed to cool naturally at 23°C for 30 minutes. The cured photocurable resin composition is then demolded from the alkali-free glass and the silicone sheet to obtain a cured film of the aforementioned photocurable resin composition.

[0159] Here, the more specific manufacturing conditions for the cured film of the photocurable resin composition of this embodiment can be, for example, the conditions described in the examples.

[0160] <Determination of in-plane phase difference Re>

[0161] For the cured film, one hour after the LED light irradiation is completed, the in-plane phase difference Re at a distance of 10.0 mm from the center of the cured film is measured using a two-dimensional birefringence evaluation device at an ambient temperature of 23°C and atmospheric conditions.

[0162] More specifically, in this embodiment, the in-plane phase difference Re can be measured according to the method described in the examples.

[0163] Next, the in-plane phase difference Re after heating, measured according to the following <Measurement of In-plane Phase Difference Re after Heat Treatment>, is explained after the curing film prepared using the photocurable resin composition of this embodiment according to the <Curing Film Preparation Conditions> described above is subjected to the following <Heat Treatment>.

[0164] <Heat Treatment>

[0165] The cured film was heated from 23°C to 120°C at a constant rate over 1 hour, heated at 120°C for 1 hour, cooled from 120°C to 23°C at a constant rate over 3 hours, and then exothermized at 23°C for 3 hours.

[0166] <Determination of in-plane phase difference Re after heat treatment>

[0167] For the cured film, one hour after the completion of the above-mentioned heat treatment, the in-plane phase difference Re at a distance of 10.0 mm from the center of the cured film is measured using a two-dimensional birefringence evaluation device at an ambient temperature of 23°C and under atmospheric conditions.

[0168] From the viewpoint of further reducing the coloration of the optically molded body, the in-plane phase difference Re of the photocurable resin composition after heating in this embodiment is preferably 10.0 nm or less, more preferably 8.0 nm or less, even more preferably 6.0 nm or less, even more preferably 5.0 nm or less, even more preferably 4.0 nm or less, even more preferably 3.5 nm or less, even more preferably 3.0 nm or less, and even more preferably 2.5 nm or less.

[0169] The lower limit of the in-plane phase difference Re after heating of the photocurable resin composition in this embodiment is not particularly limited. For example, it can be 0.0 nm or more, 0.1 nm or more, 0.5 nm or more, 1.0 nm or more, or 1.5 nm or more.

[0170] From the viewpoint of further reducing the coloration of the optically molded body, the in-plane phase difference Re of the photocurable resin composition after heating in this embodiment is preferably 0.0 nm or more and 10.0 nm or less, more preferably 0.0 nm or more and 8.0 nm or less, even more preferably 0.0 nm or more and 6.0 nm or less, even more preferably 0.0 nm or more and 5.0 nm or less, even more preferably 0.0 nm or more and 4.0 nm or less, even more preferably 0.0 nm or more and 3.5 nm or less, even more preferably 0.0 nm or more and 3.0 nm or less, and even more preferably 0.0 nm or more and 2.5 nm or less.

[0171] In this embodiment of the photocurable resin composition, the yellowness (YI value) of the cured film prepared using the photocurable resin composition according to the above-described <curing film preparation conditions>, when heated at 120°C for 1 hour, is described according to ASTM E313-73.

[0172] From the viewpoint of further reducing the coloration of the optically molded body, the YI value of the photocurable resin composition of this embodiment is preferably 6.50 or less, more preferably 6.00 or less, even more preferably 5.50 or less, even more preferably 5.00 or less, even more preferably 4.00 or less, even more preferably 3.00 or less, even more preferably 2.50 or less, even more preferably 2.00 or less, and even more preferably 1.50 or less.

[0173] The lower limit of the YI value of the photocurable resin composition in this embodiment is not particularly limited. For example, it can be 0.00 or more, 0.01 or more, 0.05 or more, or 0.10 or more.

[0174] From the viewpoint of further reducing the coloration of the optically molded body, the YI value of the photocurable resin composition of this embodiment is preferably 0.00 or more and 6.50 or less, more preferably 0.00 or more and 6.00 or less, even more preferably 0.00 or more and 5.50 or less, even more preferably 0.00 or more and 5.00 or less, even more preferably 0.00 or more and 4.00 or less, even more preferably 0.00 or more and 3.00 or less, even more preferably 0.00 or more and 2.50 or less, even more preferably 0.00 or more and 2.00 or less, even more preferably 0.00 or more and 1.50 or less.

[0175] From the viewpoint of improving the heat resistance of the optical molded body, the glass transition temperature Tg of the photocurable resin composition of this embodiment is preferably 100°C or higher, more preferably 110°C or higher, even more preferably 115°C or higher, even more preferably 120°C or higher, even more preferably 125°C or higher, and even more preferably 130°C or higher.

[0176] From the viewpoint of further reducing the coloration of the optically molded body, the glass transition temperature Tg of the photocurable resin composition of this embodiment is preferably 250°C or less, more preferably 230°C or less, even more preferably 210°C or less, even more preferably 190°C or less, even more preferably 170°C or less, even more preferably 150°C or less, and even more preferably 140°C or less.

[0177] From the viewpoint of improving the heat resistance of the optical molded article and further reducing the coloring of the optical molded article, the glass transition temperature Tg of the photocurable resin composition of this embodiment is preferably 100°C or higher and 250°C or lower, more preferably 110°C or higher and 230°C or lower, even more preferably 115°C or higher and 210°C or lower, even more preferably 120°C or higher and 190°C or lower, even more preferably 125°C or higher and 170°C or lower, even more preferably 130°C or higher and 150°C or lower, and even more preferably 130°C or higher and 140°C or lower.

[0178] <Uses of UV-curable resin compositions>

[0179] Next, the uses of the photocurable resin composition will be explained.

[0180] The photocurable resin composition of this embodiment can reduce the coloring of optical molded articles formed from the photocurable resin composition, and therefore can be used in methods for forming optical molded articles such as injection molding, compression molding, injection compression molding, extrusion molding, solution casting, and casting. In particular, the photocurable resin composition of this embodiment can be used in the casting process.

[0181] The photocurable resin composition of this embodiment can reduce the coloring of optical molded articles formed from the photocurable resin composition. Therefore, the use of optical molded articles formed from the photocurable resin composition is not particularly limited and can be used for various purposes.

[0182] The photocurable resin composition of this embodiment is preferably used for lenses, for example. As a lens, it may include, for example, one or more selected from the group consisting of spherical lenses, aspherical lenses, biconvex lenses, plano-convex lenses, convex meniscus lenses, biconcave lenses, plano-concave lenses, and concave meniscus lenses.

[0183] The photocurable resin composition of this embodiment can, for example more preferably, be used in one or more lenses selected from the group consisting of lenses for virtual reality devices (VR lenses), mixed reality devices (MR lenses), augmented reality devices (AR lenses), extended reality devices (xR lenses), and head-mounted display lenses (HMD lenses).

[0184] The photocurable resin composition of this embodiment can preferably be used, for example, as a cover plate for a display (hereinafter also referred to as a cover display). As a cover display, it may include, for example, one or more types selected from the group consisting of front cover displays and full-cover displays.

[0185] The photocurable resin composition of this embodiment can, for example, more preferably, be used in one or more overlay displays selected from the group consisting of overlay displays for virtual reality devices (VR devices), overlay displays for mixed reality devices (MR devices), overlay displays for augmented reality devices (AR devices), overlay displays for extended reality devices (xR devices), and overlay displays for head-mounted displays (HMDs).

[0186] (Optically shaped body)

[0187] The optical molded body of this embodiment comprises a cured product of the photocurable resin composition of this embodiment. The optical molded body of this embodiment can be manufactured using the photocurable resin composition of this embodiment. The optical molded body can be manufactured from the photocurable resin composition of this embodiment by any method, such as injection molding, compression molding, injection compression molding, extrusion molding, solution casting, and casting.

[0188] The optical molding body of this embodiment includes a lens. The lens may include, for example, one or more types selected from the group consisting of a spherical lens, an aspherical lens, a biconvex lens, a plano-convex lens, a convex meniscus lens, a biconcave lens, a plano-concave lens, and a concave meniscus lens.

[0189] The lens in this embodiment includes one or more types selected from the group consisting of lenses for virtual reality devices (VR lenses), lenses for mixed reality devices (MR lenses), lenses for augmented reality devices (AR lenses), lenses for extended reality devices (xR lenses), and lenses for head-mounted displays (HMD lenses).

[0190] The optical molding body of this embodiment includes a cover plate for a display (covered display). As a covered display, it includes, for example, one or more types selected from the group consisting of front covered displays and full-surface covered displays.

[0191] The overlay display in this embodiment includes one or more types selected from the group consisting of an overlay display for virtual reality devices (VR devices), an overlay display for mixed reality devices (MR devices), an overlay display for augmented reality devices (AR devices), an overlay display for extended reality devices (xR devices), and an overlay display for head-mounted displays (HMDs).

[0192] The thickest part of an optical molded body is the part with the greatest thickness of the optical components within it. The location of the thickest part of the optical molded body is not particularly limited and can be appropriately set according to the application, etc.

[0193] For example, in this embodiment, the optically shaped body preferably has a maximum thickness of 1.0 mm or more, more preferably 1.1 mm or more, even more preferably 1.2 mm or more, even more preferably 1.5 mm or more, even more preferably 2.0 mm or more, even more preferably 3.0 mm or more, even more preferably 4.0 mm or more, and even more preferably 5.0 mm or more.

[0194] For example, in this embodiment, the maximum thickness of the optical molded body is preferably 20.0 mm or less, more preferably 19.9 mm or less, even more preferably 19.8 mm or less, even more preferably 19.5 mm or less, even more preferably 18.0 mm or less, even more preferably 17.0 mm or less, even more preferably 16.0 mm or less, and even more preferably 15.0 mm or less.

[0195] For example, in this embodiment, the optical forming body preferably has a maximum thickness of 1.0 mm or more and 20.0 mm or less, more preferably 1.1 mm or more and 19.9 mm or less, even more preferably 1.2 mm or more and 19.8 mm or less, even more preferably 1.5 mm or more and 19.5 mm or less, even more preferably 2.0 mm or more and 19.0 mm or less, even more preferably 3.0 mm or more and 18.0 mm or less, even more preferably 4.0 mm or more and 17.0 mm or less, even more preferably 5.0 mm or more and 16.0 mm or less, and even more preferably 5.0 mm or more and 15.0 mm or less.

[0196] It should be noted that the photocurable resin composition of this embodiment can reduce the coloring of optical molded articles, and therefore can also be applied to optical molded articles with a thickness of 1.0 mm or more.

[0197] <Manufacturing Method of Optical Molded Objects>

[0198] The manufacturing method of the optical molded body in this embodiment includes the following steps.

[0199] • Curing process: The optically molded body is produced by curing the light-curable resin composition by irradiating it with light.

[0200] • Heating process: By heating the optical molded body, the coloring of the optical molded body is reduced.

[0201] <Curing Process>

[0202] In the curing process, a photocurable resin composition is cured by irradiating it with light, thereby producing an optically molded body. The type and shape of the apparatus used in the curing process vary appropriately depending on the properties of the photocurable resin composition used in the optically molded body or the shape of the optically molded body, and therefore are not particularly limited. Furthermore, the curing conditions in the curing process (wavelength of the irradiated light, intensity of the irradiated light, irradiation time, or atmosphere during irradiation (temperature, humidity, air pressure, or type of gas, etc.)) vary appropriately depending on the properties of the photocurable resin composition used in the optically molded body or the shape of the optically molded body, and therefore are not particularly limited.

[0203] The optically molded body of this embodiment is preferably formed by irradiating the photocurable resin composition of this embodiment with LED light to polymerize and cure the photocurable resin composition.

[0204] LED light can also be ultraviolet light. Ultraviolet light includes UVC (Ultraviolet C) with a wavelength of 200~280nm, UVB (Ultraviolet B) with a wavelength of 280~315nm, and UVA (Ultraviolet A) with a wavelength of 315~405nm.

[0205] When using ultraviolet light, light sources such as sunlight, chemical lamps, mercury lamps, metal halide lamps, or UV LEDs can be used.

[0206] From the viewpoint of improving the appearance of the obtained optically molded article, the irradiation intensity of ultraviolet light is preferably 500 mW or more and 1000 mW or less, more preferably 700 mW or more and 950 mW or less, more preferably 750 mW or more and 900 mW or less, and more preferably 800 mW or more and 850 mW or less. Furthermore, the irradiation intensity of ultraviolet light refers to the intensity of ultraviolet light irradiation.

[0207] From the viewpoint of improving the appearance of the resulting optically shaped article, the cumulative light intensity of ultraviolet irradiation is preferably 100 J or more and 500 J or less, more preferably 150 J or more and 400 J or less, even more preferably 200 J or more and 350 J or less, and even more preferably 250 J or more and 300 J or less. It should be noted that the cumulative light intensity of ultraviolet irradiation refers to the total cumulative light intensity of ultraviolet radiation.

[0208] <Heating Process>

[0209] In the heating process, the coloring of the optical molded body is reduced by heating the optical molded body.

[0210] It should be noted that the reason why heating the optically shaped body can reduce the coloration of the optically shaped body is not clear, but it is speculated to be the following reason.

[0211] It is believed that organic free radicals generated during the curing of the photocurable resin composition sometimes remain in the optically molded body after the curing process. It is thought that the increased coloration of the optically molded body is due to these residual organic free radicals.

[0212] It is believed that heating the optically molded body after the curing process reduces the amount of residual organic free radicals or the chemical structures generated due to residual organic free radicals. Therefore, it is believed that heating the optically molded body after the curing process can reduce the coloration of the optically molded body.

[0213] In the heating process, the type and shape of the apparatus used vary appropriately depending on the properties of the photocurable resin composition used in the optical molding or the shape of the optical molding, and therefore are not particularly limited. Furthermore, the heating conditions in the heating process (heating unit, heating temperature, heating time, heating rate, cooling rate, or the atmosphere during heating (temperature, humidity, air pressure, or type of gas, etc.)) vary appropriately depending on the properties of the photocurable resin composition used in the optical molding or the shape of the optical molding, and therefore are not particularly limited.

[0214] In the heating process, from the viewpoint of further reducing the coloring of the optical molded body, the heating temperature for heating the optical molded body is preferably 80°C or higher, more preferably 90°C or higher, even more preferably 100°C or higher, even more preferably 110°C or higher, and even more preferably 115°C or higher.

[0215] In the heating process, from the viewpoint of reducing deformation of the optical molded body, the heating temperature for heating the optical molded body is preferably lower than the glass transition temperature Tg+20°C of the photocurable resin composition. In other words, in the heating process, from the viewpoint of reducing deformation of the optical molded body, the heating temperature for heating the optical molded body is preferably lower than the glass transition temperature Tg+20°C of the optical molded body.

[0216] For example, when the glass transition temperature Tg of the photocurable resin composition is X [°C], in the heating process, from the viewpoint of reducing the deformation of the optical molded body, the heating temperature for heating the optical molded body is preferably less than (X+20) [°C], more preferably less than (X+10) [°C], even more preferably less than (X+5) [°C], even more preferably less than X [°C], even more preferably less than (X-3) [°C], even more preferably less than (X-5) [°C], even more preferably less than (X-7) [°C], and even more preferably less than (X-10) [°C].

[0217] In the heating process, from the viewpoint of further reducing the coloration of the optical molded body, when the glass transition temperature Tg of the photocurable resin composition is X [°C], the heating temperature of the optical molded body is preferably 80°C or higher and less than (X+20) [°C], more preferably 90°C or higher and less than (X+10) [°C], even more preferably 100°C or higher and less than (X+5) [°C], even more preferably 110°C or higher and less than X [°C], even more preferably 115°C or higher and less than (X-3) [°C], even more preferably 115°C or higher and less than (X-5) [°C], even more preferably 115°C or higher and less than (X-7) [°C], and even more preferably 115°C or higher and less than (X-10) [°C].

[0218] In the heating process, from the viewpoint of further reducing the coloration of the optical molded body, the heating time for heating the optical molded body is preferably 1 minute or more, more preferably 5 minutes or more, even more preferably 10 minutes or more, even more preferably 20 minutes or more, even more preferably 30 minutes or more, even more preferably 40 minutes or more, even more preferably 50 minutes or more, and even more preferably 55 minutes or more.

[0219] In the heating process, there is no particular limit to the upper limit of the heating time for heating the optical forming body; for example, it can be less than 120 minutes or less than 90 minutes.

[0220] In the heating process, from the viewpoint of further reducing the coloration of the optical molded body, the heating time for heating the optical molded body is preferably 1 minute or more and 120 minutes or less, more preferably 5 minutes or more and 120 minutes or less, even more preferably 10 minutes or more and 120 minutes or less, even more preferably 20 minutes or more and 120 minutes or less, even more preferably 30 minutes or more and 120 minutes or less, even more preferably 40 minutes or more and 90 minutes or less, even more preferably 50 minutes or more and 90 minutes or less, even more preferably 55 minutes or more and 90 minutes or less.

[0221] (Optical equipment)

[0222] The optical device of this embodiment includes the optical molding body of this embodiment. The type of optical device in this embodiment is not particularly limited. Examples of optical devices in this embodiment include virtual reality devices (VR devices), mixed reality devices (MR devices), augmented reality devices (AR devices), extended reality devices (xR devices), and head-mounted displays (HMD devices).

[0223] The embodiments of the present invention have been described above, but these are merely examples of the present invention, and various configurations other than those described above are also possible.

[0224] Furthermore, the present invention is not limited to the embodiments described above, and modifications and improvements made within the scope of not impairing the effects of the present invention are included in the present invention.

[0225] Example

[0226] Hereinafter, this embodiment will be described in detail with reference to the examples and other relevant documents. It should be noted that this embodiment is not limited in any way by the descriptions in these examples.

[0227] First, the materials used in each example are shown.

[0228] Polymerizable compound: (meth)acrylate monomer (A)

[0229] Monofunctional (meth)acrylate monomer (A1): GM81HDA (dicyclopentyl methacrylate, manufactured by Guojing Chemical Co., Ltd.)

[0230] 2 or more functional (meth)acrylate monomers (A2)1:DCP (tricyclodecanediethanol dimethacrylate, manufactured by Shin-Nakamura Chemical Industry Co., Ltd.)

[0231] (A2)2: DDD (1,12-dodecanediol dimethacrylate, manufactured by Shin-Nakamura Chemical Industry Co., Ltd.) is a 2-functional or higher (meth)acrylate monomer.

[0232] • Antioxidants (B)

[0233] Antioxidant 1: Thioether-based antioxidant (bis[3-(dodecylthio)propionic acid]2,2-bis[[3-(dodecylthio)-1-oxopropoxy]methyl]-1,3-propanediyl ester, manufactured by ADEKA Co., Ltd., product name: ADK STAB AO-412S) (hereinafter also referred to as AO-412S)

[0234] Antioxidant 2: Phenolic antioxidant (Pentaerythritol tetra[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate], manufactured by ADEKA Co., Ltd., product name: ADK STAB AO-60) (hereinafter also referred to as AO-60)

[0235] Photopolymerization initiator (C)

[0236] Photopolymerization initiator 1: Photoradical polymerization initiator (1-hydroxycyclohexylphenyl ketone, manufactured by IGM Resins, product name: Omnirad 184)

[0237] • Light stabilizer (D)

[0238] Light stabilizer 1: Hindered amine light stabilizer (1,2,2,6,6-pentamethyl-4-piperidinyl methacrylate, manufactured by ADEKA Corporation, product name: ADK STAB LA-82) (hereinafter also referred to as LA-82)

[0239] (Examples 1-2, Comparative Example 1)

[0240] The components were combined in the manner shown in Table 1 to obtain a liquid photocurable resin composition. It should be noted that the units for the composition in Table 1 are parts by mass.

[0241] The physical properties of the photocurable resin compositions or their cured products obtained in each example were determined by the following methods. The results are shown in Table 1.

[0242] <Determination of in-plane phase difference Re>

[0243] Using the photocurable resin compositions of each example, the in-plane phase difference Re of the cured film prepared according to the <Curing Film Preparation Conditions> below, as measured according to the <Determination of In-Plane Phase Difference Re> below, was determined.

[0244] <Conditions for Curing Film Production>

[0245] A 3mm thick, 50mm x 50mm silicone sheet (material: silicone rubber, hardness: 50 degrees) with a 35mm φ circular hole is placed on a 0.7mm thick, 50mm x 50mm alkali-free glass (product name: JIS R 3202, lightly chamfered glass plate, manufactured by TestPiece). After filling the circular hole portion of the silicone sheet with a photocurable resin composition, a 0.7mm thick, 50mm x 50mm alkali-free glass sheet (product name: JIS R 3202, lightly chamfered glass plate, manufactured by TestPiece) is further placed on top. At this time, it is confirmed that no air bubbles are introduced. Hereinafter, the component formed by placing a silicone sheet on the above-mentioned alkali-free glass, filling the circular hole portion of the silicone sheet with a photocurable resin composition, and then further placing alkali-free glass on top is sometimes referred to as a laminate.

[0246] The obtained laminate was placed on a SUS-made laboratory lift platform with its height adjusted. Using an LED irradiation device (CCS, product name: 405nm-120mm air-cooled intermittent irradiation device, model: HLDL-120505-NWPSC), the photocurable resin composition was irradiated with 405nm LED light at 810mW for 3 minutes from above the alkali-free glass. Then, the laminate was flipped and irradiated with 405nm LED light at 810mW for 3 minutes. After irradiation, the laminate was allowed to cool naturally at 23°C for 30 minutes. After natural cooling, the cured photocurable resin composition was demolded from the alkali-free glass and silicone wafer to obtain the cured film of the photocurable resin composition.

[0247] It should be noted that the intensity of the LED light irradiation was measured using an ultraviolet cumulative photometer (product name: UIT-250, manufactured by USHIO Electric Co., Ltd.).

[0248] <Determination of in-plane phase difference Re>

[0249] For each example of the cured film, one hour after the LED light irradiation is completed, the in-plane phase difference Re at a distance of 10.0 mm from the center of the cured film is measured using a two-dimensional birefringence evaluation device at an ambient temperature of 23°C and under atmospheric conditions, according to the following <Measurement Conditions for In-Plane Phase Difference Re> and the following <Measurement Procedure>.

[0250] <Conditions for measuring in-plane phase difference Re>

[0251] • Apparatus: Two-dimensional birefringence evaluation apparatus (Product name: WPA-200, manufactured by Photonic Lattice)

[0252] Analysis software: WPA-view

[0253] • Measurement temperature: 23℃

[0254] • Atmospheric pressure

[0255] • Selected area: Within a radius of 17.5 mm from the center of the cured film.

[0256] • Analysis area: Within a radius of 10.0 mm from the center of the cured film.

[0257] • Measurement field of view: 30mm × 40mm

[0258] • Birefringence pixel count: 384×288 pixels

[0259] • Lens: Standard lens (f 1.25)

[0260] User settings

[0261] Automatic exposure adjustment: Automatic exposure adjustment is performed during measurement.

[0262] Noise Filter: Automatic Application

[0263] Masking of dark areas: Apply masking (10.0%)

[0264] Axial setting: Slow axis

[0265] Measurement accuracy: High precision

[0266] Measurement mode: 3-wavelength measurement

[0267] Material coefficient: Automatic

[0268] <Measurement Steps>

[0269] (S1) After turning on the power to the device and starting the software (WPA-view), wait at least 30 minutes for it to stabilize.

[0270] (S2) After placing the curing film on the light source stage, adjust the height of the camera unit while retracting the curing film into the area of ​​the light source stage reflected in the camera preview window. At this time, prevent the curing film from floating off the light source stage. Additionally, visually confirm in the preview window that no external light is reflected.

[0271] (S3) While rotating the scale of the lens, focus on the cured film. In the measurement of the cured film, align the scale of the lens with "4".

[0272] (S4) The above conditions were set in the user settings. Next, the cured film was temporarily removed, and the baseline was measured. The baseline was measured for each cured film.

[0273] (S5) After re-preparing the cured film, the measurement was carried out.

[0274] (S6) On the analysis screen, after adjusting the selected area to enter the measurement field of view as described above, measure the in-plane phase difference Re, etc.

[0275] <Determination of in-plane phase difference Re after heating>

[0276] The cured films prepared using the photocurable resin composition according to the above-described <curing film preparation conditions> were subjected to the following <heat treatment>. The in-plane phase difference Re after heating, as measured according to the following <determination of in-plane phase difference Re after heat treatment>, was determined for each example of the cured film after the following <heat treatment>.

[0277] It should be noted that the heating of the curing film in each example begins more than 1 hour but within 3 hours after the curing film is made.

[0278] <Heat Treatment>

[0279] The cured film was heated from 23°C to 120°C at a constant rate in 1 hour, heated at 120°C for 1 hour, cooled from 120°C to 23°C at a constant rate in 3 hours, and further heat-released at 23°C for 3 hours.

[0280] <Measurement of in-plane retardation Re after heat treatment>

[0281] For the cured film, 1 hour after the completion of the above <heat treatment>, in accordance with the above <measurement conditions of in-plane retardation Re> and the above <measurement procedure>, using a two-dimensional birefringence evaluation device, the in-plane retardation Re at a distance of 10.0 mm from the center of the cured film was measured at an ambient temperature of 23°C and under atmospheric conditions.

[0282] [Measurement of YI value]

[0283] The yellowness index (YI value) measured according to ASTM E313-73 when the cured film of each example was heated at 120°C for 1 hour was measured. The measurement conditions of the YI value are as shown in the following <measurement conditions of YI value>.

[0284] <Measurement conditions of YI value>

[0285] Measuring device: Spectrophotometer for color and haze (Product name: COH-7700, manufactured by Nippon Denshoku Industries Co., Ltd.)

[0286] Film thickness: 3 mm

[0287] Film diameter: 35 mm φ

[0288] [Table 1]

[0289]

[0290] This application claims priority based on Japanese Patent Application No. 2024-012827 filed on January 31, 2024, and incorporates the entire contents disclosed therein herein.

Claims

1. A photocurable resin composition, which is a photocurable resin composition suitable for use in optically molded articles, The cured film prepared using the aforementioned photocurable resin composition according to the following <curing film preparation conditions> has an in-plane phase difference Re of 18.0 nm or less, as measured according to the following <determination of in-plane phase difference Re>. <Conditions for Curing Film Production> A 3mm thick, 50mm × 50mm silicone sheet with a 35mm φ circular hole is placed on a 0.7mm thick, 50mm × 50mm alkali-free glass substrate. The silicone sheet is made of silicone rubber with a hardness of 50 degrees. After filling the circular hole with the photocurable resin composition, another 0.7mm thick, 50mm × 50mm alkali-free glass substrate is placed on top. The substrate is placed on an SUS-made laboratory lift platform with adjustable height. The photocurable resin composition is irradiated with 405nm LED light at 810mW for 3 minutes from above the alkali-free glass. After flipping the substrate, it is irradiated with 405nm LED light at 810mW for another 3 minutes. After natural cooling at 23°C for 30 minutes, the cured photocurable resin composition is demolded from the alkali-free glass and the silicone sheet to obtain the cured film of the photocurable resin composition. <Determination of in-plane phase difference Re> For the cured film, one hour after the LED light irradiation is completed, the in-plane phase difference Re at a distance of 10.0 mm from the center of the cured film is measured using a two-dimensional birefringence evaluation device at an ambient temperature of 23°C and atmospheric conditions.

2. The photocurable resin composition according to claim 1, wherein, After subjecting the cured film prepared using the aforementioned photocurable resin composition according to the <curing film preparation conditions> to the following <heat treatment>, the in-plane phase difference Re after heating, as measured according to the following <determination of in-plane phase difference Re after heat treatment>, is 10.0 nm or less. <Heat Treatment> The cured film was heated from 23°C to 120°C at a constant rate over 1 hour, heated at 120°C for 1 hour, and then cooled from 120°C to 23°C at a constant rate over 3 hours. Finally, it was heated at 23°C for 3 hours to release heat. <Determination of in-plane phase difference Re after heat treatment> For the cured film, one hour after the completion of the <heat treatment>, the in-plane phase difference Re at a distance of 10.0 mm from the center of the cured film is measured using a two-dimensional birefringence evaluation device at an ambient temperature of 23°C and under atmospheric conditions.

3. The photocurable resin composition according to claim 1 or 2, wherein, The yellowness (YI) of the cured film prepared using the aforementioned photocurable resin composition according to the aforementioned <Curing Film Preparation Conditions>, when heated at 120°C for 1 hour, is measured according to ASTM E313-73 and is below 6.

50.

4. The photocurable resin composition according to any one of claims 1 to 3, comprising one or more selected from the group consisting of monofunctional (meth)acrylate monomers and (meth)acrylate monomers with two or more functions.

5. The photocurable resin composition according to claim 4, wherein, When the total content of the monofunctional (meth)acrylate monomer and the (meth)acrylate monomer with two or more functions is set to 100 parts by mass, the content of the (meth)acrylate monomer with two or more functions is 5.0 parts by mass or more and 90 parts by mass or less.

6. The photocurable resin composition according to claim 4 or 5, wherein, The mass ratio of the content of the monofunctional (meth)acrylate monomer to the content of the difunctional or more functional (meth)acrylate monomer is 0.50 or more and 10.0 or less.

7. The photocurable resin composition according to any one of claims 4 to 6, wherein, The monofunctional (meth)acrylate monomer has an alicyclic skeleton.

8. The photocurable resin composition according to any one of claims 4 to 7, wherein, The (meth)acrylate monomers with two or more functions have an alicyclic backbone.

9. The photocurable resin composition according to any one of claims 4 to 8, wherein, The (meth)acrylate monomers with two or more functions have a straight-chain hydrocarbon backbone.

10. The photocurable resin composition according to any one of claims 1 to 9, further comprising an antioxidant.

11. The photocurable resin composition according to any one of claims 1 to 10, further comprising a photopolymerization initiator.

12. The photocurable resin composition according to claim 11, wherein, The photopolymerization initiator includes a photoradical polymerization initiator.

13. The photocurable resin composition according to any one of claims 1 to 12, further comprising a light stabilizer.

14. The photocurable resin composition according to any one of claims 1 to 13, which can be used in casting.

15. The photocurable resin composition according to any one of claims 1 to 14, which can be used for one or more lenses selected from the group consisting of lenses for virtual reality devices (VR lenses), lenses for mixed reality devices (MR lenses), lenses for augmented reality devices (AR lenses), lenses for extended reality devices (xR lenses), and lenses for head-mounted displays (HMD lenses).

16. An optically molded article comprising a cured product of the photocurable resin composition according to any one of claims 1 to 15.

17. The optically shaped article according to claim 16, wherein, The optical molding includes a lens.

18. The optically shaped article according to claim 17, wherein, The lens includes one or more types selected from the group consisting of a VR lens for virtual reality devices, a MR lens for mixed reality devices, an AR lens for augmented reality devices, an xR lens for extended reality devices, and an HMD lens for head-mounted displays.

19. The optically shaped article according to any one of claims 16 to 18, wherein, The maximum thickness is less than 20.0 mm.

20. The optically shaped article according to any one of claims 16 to 19, wherein, The maximum thickness is 1.0 mm or more.

21. An optical device comprising the optical molding body according to any one of claims 16 to 20.

22. A method for manufacturing an optically shaped object, comprising: The curing process involves curing the photocurable resin composition according to any one of claims 1 to 15 by irradiating it with light, thereby producing an optically molded body; as well as The heating process involves heating the optical molded body to reduce its coloration.

23. The method for manufacturing an optically shaped object according to claim 22, wherein, In the heating process, the heating temperature for heating the optical molding body is above 80°C.

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