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 capable of being used for an optical molded body, the photocurable resin composition having an absorbance at a wavelength of 405 nm of 0.300 or less as determined by a specific method.

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. In particular, the photocurable composition obtained has excellent properties required for lenses, such as colorless transparency, 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 surface unevenness 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 absorbance at 405 nm of the photocurable resin composition, measured under specific conditions, and the surface unevenness 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 absorbance of 0.300 or less at 405 nm, measured under specific conditions, the surface unevenness of the optically molded article can be reduced, thus completing the present invention. [1]

[0017] A photocurable resin composition, which is a photocurable resin composition suitable for use in optically molded articles, wherein the absorbance A of the photocurable resin composition at a wavelength of 405 nm is measured according to the following <Measurement Method>. 405 It is below 0.300.

[0018] <Determination Method>

[0019] A sample was prepared by dissolving the above-mentioned photocurable resin composition in isopropanol at a mass ratio of 7:93. The sample was then placed in a sample cell with an optical path length of 10 mm. The transmitted light intensity I of the light passing through the sample cell when light with a wavelength of 405 nm and an incident light intensity I0 was incident on the sample cell was measured. The absorbance A at a wavelength of 405 nm was calculated using the following formula (1). 405 .

[0020] (1): A 405 =-log 10 (I / I0) [2]

[0022] According to the photocurable resin composition described above [1], wherein the absorbance A is... 405 It is above 0.010. [3]

[0024] The photocurable resin composition according to [1] or [2] above contains (meth)acrylate monomers. [4]

[0026] According to the photocurable resin composition described above [3], the (meth)acrylate monomer comprises one or more selected from the group consisting of monofunctional (meth)acrylate monomers and (meth)acrylate monomers with two or more functions. [5]

[0028] According to the photocurable resin composition described above [3] or [4], wherein the (meth)acrylate monomer comprises a (meth)acrylate monomer having an alicyclic backbone. [6]

[0030] According to the photocurable resin composition described above [5], the (meth)acrylate monomer having an alicyclic skeleton comprises one or more skeletons selected from the group consisting of adamantane skeleton, norbornene skeleton and dicyclopentadiene skeleton. [7]

[0032] According to the photocurable resin composition described in [5] or [6] above, when the total content of the (meth)acrylate monomer is set to 100 parts by mass, the content of the (meth)acrylate monomer having an alicyclic skeleton is 30 parts by mass or more and 100 parts by mass or less. [8]

[0034] The photocurable resin composition according to any one of [3] to [7] above, wherein the (meth)acrylate monomer comprises a (meth)acrylate monomer having a straight-chain hydrocarbon backbone. [9]

[0036] The photocurable resin composition according to any one of [1] to [8] above further comprises a photopolymerization initiator.

[10]

[0038] According to the photocurable resin composition described above [9], the photopolymerization initiator comprises a photoradical polymerization initiator.

[11]

[0040] According to the photocurable resin composition described in [9] or

[10] above, when the total content of (meth)acrylate monomer is set to 100 parts by mass, the content of the photopolymerization initiator is 0.10 parts by mass or more and 10 parts by mass or less.

[12]

[0042] The photocurable resin composition according to any one of [1] to

[11] above further comprises an antioxidant.

[13]

[0044] According to the photocurable resin composition described above

[12] , when the total content of (meth)acrylate monomer is set to 100 parts by mass, the content of the antioxidant is 0.010 parts by mass or more and 10 parts by mass or less.

[14]

[0046] The photocurable resin composition according to any one of [1] to

[13] above further comprises a light stabilizer.

[15]

[0048] According to the photocurable resin composition described above

[14] , when the total content of (meth)acrylate monomer is set to 100 parts by mass, the content of the light stabilizer is 0.010 parts by mass or more and 5 parts by mass or less.

[16]

[0050] According to any one of the above-mentioned photocurable resin compositions [1] to

[15] , wherein when the total amount of the above-mentioned photocurable resin composition is set to 100% by mass, the content of (meth)acrylate monomer is 80% by mass or more and less than 100% by mass.

[17]

[0052] The photocurable resin composition according to any one of [1] to

[16] above can be used in casting.

[18]

[0054] An optically molded body comprising a cured product of the photocurable resin composition described in any one of [1] to

[17] above.

[19]

[0056] According to the optical molding body described above

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

[20]

[0058] According to the optical shaping body described above

[19] , 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). [twenty one]

[0060] The optical molding body according to any one of

[18] to

[20] above, wherein the maximum thickness portion is 20.0 mm or less. [twenty two]

[0062] The optical molding body according to any one of

[18] to

[21] above, wherein the maximum thickness of the optical molding body is 1.0 mm or more. [twenty three]

[0064] An optical device comprising the optical molding body described in any one of

[18] to

[22] above. [twenty four]

[0066] A method for manufacturing an optically shaped object, comprising:

[0067] In the thickening process, an irradiation device with a light source peak at a wavelength above 360 ​​nm and below 410 nm is used to irradiate the photocurable resin composition, thereby increasing the viscosity of the photocurable resin composition; and

[0068] In the curing process, after the thickening process described above, the photocurable resin composition is irradiated with light using an irradiation device having a light source peak at a wavelength of 360 nm or higher and 410 nm or lower, thereby curing the photocurable resin composition.

[25]

[0070] According to the method for manufacturing an optical molded body described above

[24] , after the thickening process and before the curing process, an upper mold setting process is further included, in which an upper mold for molding is set on the photocurable resin composition.

[26]

[0072] The method for manufacturing an optical molded body according to

[24] or

[25] above further includes a coating step of coating the above-mentioned photocurable resin composition onto a lower mold for molding, wherein the above-mentioned thickening step is performed after the above-mentioned coating step.

[27]

[0074] The method for manufacturing an optical molded body according to any one of

[24] to

[26] above, wherein the thickening process includes: irradiating the photocurable resin composition with light at an irradiation intensity of 90mW or more and 130mW or less using an irradiation device having a light source peak at a wavelength of 360nm or more and 410nm or less.

[28]

[0076] The method for manufacturing an optical molded body according to any one of

[24] to

[27] above, wherein the thickening process includes: irradiating the photocurable resin composition with light for an irradiation time of 1 second to 300 seconds using an irradiation device having a light source peak at a wavelength of 360 nm or more and 410 nm or less.

[29]

[0078] The method for manufacturing an optical molded body according to any one of

[24] to

[28] above, wherein the thickening step includes: irradiating the photocurable resin composition with light at a cumulative light intensity of 50 mJ or more and 20.0 J or less using an irradiation device having a light source peak at a wavelength of 360 nm or more and 410 nm or less.

[30]

[0080] The method for manufacturing an optical molded body according to any one of

[24] to

[29] above, wherein, in the above thickening process, the thickness of the above photocurable resin composition is 15.0 mm or less.

[31]

[0082] The method for manufacturing an optical molded body according to any one of

[24] to

[30] above, wherein the photocurable resin composition comprises any one of [1] to

[17] above.

[0083] Invention Effects

[0084] According to the present invention, a photocurable resin composition that can reduce surface unevenness of optically molded articles can be provided. Detailed Implementation

[0085] The term "(meth)acrylate" in this specification includes both acrylate and methacrylate. The same applies to terms such as "(meth)acryloyl" and similar expressions.

[0086] For each component in this embodiment, one type may be used, or two or more types may be used in combination. Additionally, the "~" symbol, indicating a numerical range, represents "above" or "below," including both upper and lower limits.

[0087] (Photocurable resin composition)

[0088] The photocurable resin composition of this embodiment (hereinafter also appropriately referred to as "resin composition") is a photocurable resin composition that can be used in optically molded articles.

[0089] The absorbance A of the photocurable resin composition of this embodiment at a wavelength of 405 nm was measured according to the following <Measurement Method>. 405 It is below 0.300.

[0090] <Determination Method>

[0091] A sample was prepared by dissolving the photocurable resin composition in isopropanol at a mass ratio of 7:93. The sample was then placed in a sample cell with an optical path length of 10 mm, and the transmitted light intensity I was measured when light with a wavelength of 405 nm and an incident light intensity I0 was incident on the sample cell. The absorbance A at a wavelength of 405 nm was calculated using the following formula (2). 405 .

[0092] (2): A 405 =-log 10 (I / I0)

[0093] The photocurable resin composition of this embodiment, by having the structure described above, can reduce surface unevenness of the optically molded body.

[0094] The photocurable resin composition may contain, for example, a polymeric compound. From the viewpoint of further reducing surface unevenness of the optically molded article, the polymeric compound preferably contains a (meth)acrylate monomer (A).

[0095] 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.

[0096] Furthermore, from the viewpoint of increasing the design freedom of optically molded bodies, photocurable resin compositions are preferably used for molding using casting methods.

[0097] Next, specific examples will be given to illustrate the composition of the photocurable resin composition.

[0098] 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.

[0099] <Polymerizing compounds>

[0100] 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 surface unevenness of the optically molded body, examples of free radical polymerizable functional groups include (meth)acryloyl groups. From the viewpoint of further reducing surface unevenness of the optically molded body, the polymerizable compound preferably contains a (meth)acrylate monomer (A).

[0101] <(Meth)acrylate monomer (A)>

[0102] (Meth)acrylate monomer (A) is a compound containing an acryloyl group. (Meth)acrylate monomer (A) is a molecule that can bond with other molecules through free radical polymerization via the (meth)acryloyl group.

[0103] From the viewpoint of improving the strength of the optically molded article obtained from the photocurable resin composition, the (meth)acrylate monomer (A) preferably includes one or more selected from the group consisting of a monofunctional (meth)acrylate monomer (A1) and a (meth)acrylate monomer (A2) with two or more functions.

[0104] Regarding the content of monofunctional (meth)acrylate monomer (A1) in the photocurable resin composition of this embodiment, from the viewpoint of further reducing surface unevenness of the optically molded article, when the total content of (meth)acrylate monomer (A) is set to 100 parts by mass, it is preferably 0 parts by mass or more and 99 parts by mass or less, more preferably 10 parts by mass or more and 95 parts by mass or less, even more preferably 30 parts by mass or more and 90 parts by mass or less, even more preferably 50 parts by mass or more and 90 parts by mass or less, even more preferably 60 parts by mass or more and 85 parts by mass or less, and even more preferably 70 parts by mass or more and 85 parts by mass or less.

[0105] From the viewpoint of further reducing surface unevenness of the optically molded body, when the total content of (meth)acrylate monomer (A) is set to 100 parts by mass, the content of (meth)acrylate monomer (A2) with two or more functions in the photocurable resin composition of this embodiment is preferably 1 part by mass or more and 100 parts by mass or less, more preferably 5 parts by mass or more and 90 parts by mass or less, even more preferably 10 parts by mass or more and 70 parts by mass or less, even more preferably 10 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 15 parts by mass or more and 30 parts by mass or less.

[0106] From the viewpoint of further reducing surface unevenness of the optically molded body, the mass ratio of the content of monofunctional (meth)acrylate monomer (A1) to the content of difunctional or more (meth)acrylate monomer (A2) in the photocurable resin composition of this embodiment is preferably 0.0 or more, more preferably 0.1 or more and 10.0 or less, even more preferably 0.5 or more and 8.0 or less, even more preferably 1.0 or more and 7.0 or less, even more preferably 1.5 or more and 6.0 or less, even more preferably 2.0 or more and 5.0 or less, even more preferably 3.0 or more and 4.5 or less.

[0107] From the viewpoint of further reducing surface unevenness of the optically molded body, the (meth)acrylate monomer (A) preferably comprises a (meth)acrylate monomer having an alicyclic backbone. From the viewpoint of further reducing surface unevenness of the optically molded body, the (meth)acrylate monomer having an alicyclic backbone is more preferably having one or more backbones selected from the group consisting of adamantane backbone, norbornene backbone, and dicyclopentadiene backbone. From the viewpoint of further reducing surface unevenness of the optically molded body, the (meth)acrylate monomer having an alicyclic backbone is further preferably comprising one or more backbones selected from the group consisting of dicyclopentyl methacrylate and isoborneol methacrylate.

[0108] From the viewpoint of further reducing surface unevenness of the optically molded body, when the total content of (meth)acrylate monomer (A) is set to 100 parts by mass, the content of (meth)acrylate monomer having an alicyclic backbone in the photocurable resin composition of this embodiment is preferably 30 parts by mass or more and 100 parts by mass or less, more preferably 40 parts by mass or more and 100 parts by mass or less, even more preferably 45 parts by mass or more and 100 parts by mass or less, even more preferably 50 parts by mass or more and 100 parts by mass or less, even more preferably 60 parts by mass or more and 100 parts by mass or less, even more preferably 70 parts by mass or more and 100 parts by mass or less, even more preferably 75 parts by mass or more and 95 parts by mass or less, even more preferably 80 parts by mass or more and 90 parts by mass or less.

[0109] From the viewpoint of further reducing surface unevenness of the optically shaped body, the (meth)acrylate monomer (A) preferably contains a (meth)acrylate monomer having a straight-chain hydrocarbon backbone, and more preferably contains 1,12-dodecanediol di(meth)acrylate.

[0110] From the viewpoint of further reducing surface unevenness of the optically molded body, when the total amount of the photocurable resin composition is set to 100% by mass, the content of (meth)acrylate monomer (A) in the photocurable resin composition of this embodiment is preferably 80% by mass or more and less than 100% by mass, more preferably 85% by mass or more and 99% by mass or less, even more preferably 90% by mass or more and 98% by mass or less, even more preferably 92% by mass or more and 97% by mass or less, and even more preferably 93% by mass or more and 96% by mass or less.

[0111] <Monofunctional (meth)acrylate monomer (A1)>

[0112] The monofunctional (meth)acrylate monomer (A1) includes, 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, etc.

[0113] The monofunctional (meth)acrylate monomer (A1) is preferably 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 methacrylate, 3-methoxybutyl methacrylate, ethoxyethyl methacrylate, butoxyethyl methacrylate, ethoxydiethylene glycol methacrylate, methoxydihexyl methacrylate, ethyl diethylene glycol methacrylate, cyclic trimethylolpropane methyl acetal mono(meth)acrylate, imide methacrylate, isoamyl methacrylate, ethoxylated succinic acid methacrylate, trifluoroethyl methacrylate, ω-carboxylated polycaprolactone mono(meth)acrylate, cyclohexyl methacrylate, 2-(2-ethoxyethoxy)ethyl methacrylate, stearyl methacrylate, meth... 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.), isodecanyl acrylate, octyl / decyl acrylate, tridecyl 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, benzyl acrylate, methylphenoxyethyl acrylate, caprolactone-modified tetrahydrofurfuryl 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.

[0114] From the viewpoint of further reducing surface unevenness of optically shaped articles, the monofunctional (meth)acrylate monomer (A1) preferably comprises a monofunctional (meth)acrylate monomer having an alicyclic backbone, more preferably comprises dicyclopentyl (meth)acrylate, and even more preferably comprises dicyclopentyl methacrylate.

[0115] <2 or more functional (meth)acrylate monomers (A2)>

[0116] 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.

[0117] 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.

[0118] 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.

[0119] 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.

[0120] 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.

[0121] 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.

[0122] From the viewpoint of further reducing surface unevenness of optically shaped bodies, the cyclic hydrocarbon group in the alicyclic difunctional (meth)acrylate monomer is preferably a group having a dicyclopentadiene backbone.

[0123] 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.).

[0124] Linear difunctional (meth)acrylate monomers are (meth)acrylates that have a linear structure in their molecular structure and have two (meth)acryloyl groups.

[0125] 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.

[0126] As a specific example of a linear difunctional (meth)acrylate monomer, di(meth)acrylate of an alkanediol can be cited.

[0127] 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.).

[0128] From the viewpoint of further reducing surface unevenness of the optically molded article, the (meth)acrylate monomer (A2) with two or more functionalities preferably has an alicyclic backbone. From the viewpoint of further reducing surface unevenness of the optically molded article, the (meth)acrylate monomer (A2) with two or more functionalities more preferably contains tricyclodecanediethanol di(meth)acrylate, and even more preferably contains tricyclodecanediethanol dimethacrylate.

[0129] From the viewpoint of further reducing surface unevenness of the optically molded article, the (meth)acrylate monomer (A2) with more than two functionalities preferably has a straight-chain hydrocarbon backbone. From the viewpoint of further reducing surface unevenness of the optically molded article, 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.

[0130] <Antioxidant (B)>

[0131] 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.

[0132] Examples of phenolic antioxidants include 2,6-di-tert-butylhydroxytoluene and pentaerythritol tetrakis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate].

[0133] 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.

[0134] Examples of phosphorus-based antioxidants include phosphines such as trialkylphosphine and triarylphosphine, as well as trialkyl phosphites and triaryl phosphites.

[0135] 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.

[0136] 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.

[0137] 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.

[0138] 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.

[0139] 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.

[0140] 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.

[0141] 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.).

[0142] From the viewpoint of further reducing the coloration of the optically molded body, when the total content of (meth)acrylate monomer (A) is set to 100 parts by mass, 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, 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.

[0143] From the viewpoint of further reducing the coloration of the optically molded body, 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 antioxidant (B) in the photocurable resin composition of this embodiment 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.

[0144] <Photopolymerization Initiator (C)>

[0145] 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.

[0146] 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.

[0147] Examples of photoradical polymerization initiators include acylphosphine oxide initiators, oxyphenyl acetate initiators, benzoylformic acid initiators, and hydroxyphenyl ketone initiators.

[0148] 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.

[0149] From the viewpoint of further reducing surface unevenness of the optically shaped body, the photopolymerization initiator (C) preferably contains a hydroxyphenyl ketone initiator, more preferably 1-hydroxycyclohexylphenyl ketone (e.g., Omnirad 184, manufactured by IGM Resins).

[0150] From the viewpoint of further reducing surface unevenness of the optically molded body, when the content of (meth)acrylate monomer (A) is set to 100 parts by mass, 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.

[0151] From the viewpoint of improving the uniformity of the thickness of the photocurable resin composition during curing, when the content of (meth)acrylate monomer (A) is set to 100 parts by weight, the content of photopolymerization initiator (C) in the photocurable resin composition of this embodiment is preferably 10 parts by weight or less, more preferably 8.0 parts by weight or less, even more preferably 6.0 parts by weight or less, even more preferably 5.0 parts by weight or less, and even more preferably 4.5 parts by weight or less.

[0152] From the viewpoint of further reducing surface unevenness of the optically molded body and improving the uniformity of thickness during curing of the photocurable resin composition, when the content of (meth)acrylate monomer (A) is set to 100 parts by mass, 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, more preferably 0.50 parts by mass or more and 8.0 parts by mass or less, even more preferably 1.0 parts by mass or more and 6.0 parts by mass or less, even more preferably 2.0 parts by mass or more and 5.0 parts by mass or less, and even more preferably 3.0 parts by mass or more and 4.5 parts by mass or less.

[0153] From the viewpoint of further reducing surface unevenness of the optically molded body, 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 photopolymerization initiator (C) in the photocurable resin composition of this embodiment 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 4.5% by mass or less.

[0154] <Light Stabilizer (D)>

[0155] 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.

[0156] From the viewpoint of further improving colorfastness, the light stabilizer (D) preferably contains a hindered amine light stabilizer.

[0157] 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-piperidin) 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-piperidin) sebacate and methyl-1,2,2,6,6- sebacate. Mixtures of pentamethyl-4-piperidine esters, bis(2,2,6,6-tetramethyl-4-piperidine) sebacate, tetra(2,2,6,6-tetramethyl-4-piperidine) ester of 1,2,3,4-butanetetracarboxylate, tetra(1,2,2,6,6-pentamethyl-4-piperidine) ester of 1,2,3,4-butanetetracarboxylate, mixtures of 2,2,6,6-tetramethyl-4-piperidine 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-piperidine ester of 1,2,3,4-butanetetracarboxylate and tridecyl ester of 1,2,3,4-butanetetracarboxylate, etc.

[0158] 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.).

[0159] From the viewpoint of further improving the colorfastness of the optically molded article, when the total content of (meth)acrylate monomer (A) is set to 100 parts by mass, the content of light stabilizer (D) in the photocurable resin composition of this embodiment is preferably 0.010 parts by mass or more and 5 parts by mass or less, more preferably 0.050 parts by mass or more and 1.0 parts by mass or less, even more preferably 0.060 parts by mass or more and 0.50 parts by mass or less, even more preferably 0.080 parts by mass or more and 0.20 parts by mass or less, and even more preferably 0.090 parts by mass or more and 0.11 parts by mass or less.

[0160] From the viewpoint of further reducing surface unevenness of the optically molded body, 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, 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, even more preferably 0.090% by mass or more, even more preferably 0.094% by mass or more, and even more preferably 0.095% by mass or more.

[0161] From the viewpoint of reducing exudation, 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, the content of light stabilizer (D) in the photocurable resin composition of this embodiment is preferably 1.0% 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.

[0162] From the viewpoints of further reducing surface unevenness 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 1.0% 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, even more preferably 0.090% by mass or more and 0.30% by mass or less, even more preferably 0.094% by mass or more and 0.20% by mass or less, and even more preferably 0.095% by mass or more and 0.10% by mass or less.

[0163] <Other Ingredients>

[0164] 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).

[0165] <Method for manufacturing photocurable resin compositions>

[0166] The photocurable resin composition of this embodiment can be obtained by mixing a polymerizable 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.

[0167] <Physical Properties of Photocurable Resin Compositions>

[0168] Next, the physical properties of the photocurable resin composition will be described.

[0169] The absorbance A of the photocurable resin composition of this embodiment at a wavelength of 405 nm, measured according to the following <Measurement Method>. 405 Please provide an explanation.

[0170] From the perspective of reducing surface unevenness of optically shaped objects, absorbance A 405 The value is 0.300 or less, preferably 0.250 or less, more preferably 0.200 or less, even more preferably 0.150 or less, even more preferably 0.100 or less, even more preferably 0.050 or less, and even more preferably 0.030 or less.

[0171] From the viewpoint that a photocurable resin composition can be cured with light at a wavelength of 405 nm, absorbance A 405 Preferably, it is 0.000 or more, more preferably 0.005 or more, even more preferably 0.010 or more, and even more preferably 0.015 or more.

[0172] From the perspective of reducing surface unevenness of optically shaped objects, absorbance A 405 Preferably, the value is 0.000 or more and 0.300 or less, more preferably 0.005 or more and 0.250 or less, even more preferably 0.010 or more and 0.200 or less, even more preferably 0.010 or more and 0.150 or less, even more preferably 0.010 or more and 0.100 or less, even more preferably 0.010 or more and 0.050 or less, even more preferably 0.015 or more and 0.030 or less.

[0173] <Determination Method>

[0174] A sample was prepared by dissolving the photocurable resin composition in isopropanol at a mass ratio of 7:93. The sample was then placed in a sample cell with an optical path length of 10 mm, and light with a wavelength of 405 nm and an incident light intensity I0 was incident into the sample cell. The transmitted light intensity I was measured. After measurement, the absorbance A at a wavelength of 405 nm was calculated using the following formula (3). 405 .

[0175] (3): A 405 =-log 10 (I / I0)

[0176] More specifically, in this embodiment, the <measurement method> can be performed according to the method described in the examples.

[0177] <Uses of UV-curable resin compositions>

[0178] Next, the uses of the photocurable resin composition will be explained.

[0179] The photocurable resin composition of this embodiment can reduce surface unevenness of optical molded articles, 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 casting.

[0180] The photocurable resin composition of this embodiment can reduce surface unevenness of the optical molded article. Therefore, the use of the optical molded article formed by the photocurable resin composition is not particularly limited and can be used for various purposes.

[0181] 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.

[0182] 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).

[0183] 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.

[0184] 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).

[0185] (Optical shaped body)

[0186] 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.

[0187] The optical molded body of this embodiment can be manufactured using the photocurable resin composition of this embodiment, by the manufacturing method of the optical molded body of this embodiment described later.

[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 surface unevenness 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 optically shaped objects)

[0198] Hereinafter, the steps of the manufacturing method of the optical molded body of this embodiment, as well as the raw materials used in the manufacturing method of the optical molded body of this embodiment, will be described.

[0199] It should be noted that the photocurable resin composition used in the manufacturing method of the optical molded body of this embodiment preferably includes the photocurable resin composition of this embodiment.

[0200] The manufacturing method of the optical molded body in this embodiment includes the following steps.

[0201] • Thickening process: The photocurable resin composition is irradiated with light using an irradiation device with a light source peak at a wavelength of 360nm or higher and 410nm or lower, thereby increasing the viscosity of the photocurable resin composition.

[0202] • Curing process: After the thickening process, the photocurable resin composition is irradiated with light using an irradiation device with a light source peak at a wavelength of 360 nm or higher and 410 nm or lower, thereby curing the photocurable resin composition.

[0203] The method for manufacturing an optical molded body according to this embodiment, by having the above-described configuration, can reduce surface unevenness of the optical molded body.

[0204] <Thickening process>

[0205] In the thickening process, an irradiation device with a light source peak at a wavelength of 360 nm or higher and 410 nm or lower is used to irradiate the photocurable resin composition, thereby increasing the viscosity of the photocurable resin composition. The type and shape of the device used in the thickening process 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 curing conditions in the thickening 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 optical molding or the shape of the optical molding, and therefore are not particularly limited.

[0206] From the viewpoint of reducing surface unevenness of the optically molded body, the light source peak of the irradiation device used in the thickening process of this embodiment is located at a wavelength of 360 nm or more and 410 nm or less, preferably at a wavelength of 370 nm or more and 410 nm or less, more preferably at a wavelength of 380 nm or more and 410 nm or less, even more preferably at a wavelength of 390 nm or more and 410 nm or less, and even more preferably at a wavelength of 400 nm or more and 410 nm or less.

[0207] In the thickening process of this embodiment, from the viewpoint of further reducing surface unevenness of the optically molded body, the irradiation intensity when irradiating the photocurable resin composition with an irradiation device having a light source peak at a wavelength of 360 nm or more and 410 nm or less is preferably 90 mW or more and 130 mW or less, more preferably 100 mW or more and 120 mW or less, even more preferably 105 mW or more and 115 mW or less, and even more preferably 110 mW.

[0208] In other words, from the viewpoint of further reducing surface unevenness of the optically molded body, the thickening process of this embodiment includes: irradiating the photocurable resin composition with light at the above-mentioned irradiation intensity (preferably 90mW or more and 130mW or less, more preferably 100mW or more and 120mW or less, even more preferably 105mW or more and 115mW or less, and even more preferably 110mW) using an irradiation device having a light source peak at a wavelength of 360nm or more and 410nm or less.

[0209] In the thickening process of this embodiment, from the viewpoint of further reducing surface unevenness of the optically molded body, the irradiation time when irradiating the photocurable resin composition with an irradiation device having a light source peak at a wavelength of 360 nm or more and 410 nm or less is preferably 1 second or more and 300 seconds or less, more preferably 10 seconds or more and 240 seconds or less, even more preferably 30 seconds or more and 120 seconds or less, even more preferably 45 seconds or more and 90 seconds or less, and even more preferably 50 seconds or more and 70 seconds or less.

[0210] In other words, from the viewpoint of further reducing surface unevenness of the optically molded body, the thickening process of this embodiment includes: irradiating the photocurable resin composition with light using an irradiation device having a light source peak at a wavelength of 360 nm or more and 410 nm or less for the aforementioned irradiation time (preferably 1 second or more and 300 seconds or less, more preferably 10 seconds or more and 240 seconds or less, even more preferably 30 seconds or more and 120 seconds or less, even more preferably 45 seconds or more and 90 seconds or less, even more preferably 50 seconds or more and 70 seconds or less).

[0211] In the thickening process of this embodiment, from the viewpoint of further reducing surface unevenness of the optically molded body, the cumulative light intensity when irradiating the photocurable resin composition with an irradiation device having a light source peak at a wavelength of 360 nm or more and 410 nm or less is preferably 50 mJ or more and 20.0 J or less, more preferably 100 mJ or more and 15.0 J or less, even more preferably 1.0 J or more and 10.0 J or less, even more preferably 5.0 J or more and 8.0 J or less, and even more preferably 6.0 J or more and 7.0 J or less.

[0212] In other words, from the viewpoint of further reducing surface unevenness of the optically molded body, the thickening process of this embodiment includes: irradiating the photocurable resin composition with light using an irradiation device having a light source peak at a wavelength of 360 nm or more and 410 nm or less, with the aforementioned cumulative light intensity (preferably 50 mJ or more and 20.0 J or less, more preferably 100 mJ or more and 15.0 J or less, even more preferably 1.0 J or more and 10.0 J or less, even more preferably 5.0 J or more and 8.0 J or less, even more preferably 6.0 J or more and 7.0 J or less).

[0213] In the thickening process, from the viewpoint of further reducing surface unevenness of the optically molded body, the thickness of the photocurable resin composition is preferably 1.0 mm or more and 20.0 mm or less, more preferably 1.5 mm or more and 19.0 mm or less, even more preferably 2.0 mm or more and 18.0 mm or less, even more preferably 2.5 mm or more and 17.0 mm or less, even more preferably 2.7 mm or more and 16.0 mm or less, and even more preferably 2.9 mm or more and 15.0 mm or less.

[0214] <Curing Process>

[0215] In the curing process, an irradiation device with a light source peak at a wavelength above 360 ​​nm and below 410 nm is used to irradiate the photocurable resin composition, thereby curing the photocurable resin composition. The curing process is performed after the thickening process.

[0216] 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 optical molding or the shape of the optical molding, 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 optical molding or the shape of the optical molding, and therefore are not particularly limited.

[0217] The light irradiating the photocurable resin composition can be, for example, ultraviolet light. Ultraviolet light includes UVC (Ultraviolet C) with a wavelength of 200-280 nm, UVB (Ultraviolet B) with a wavelength of 280-315 nm, and UVA (Ultraviolet A) with a wavelength of 315-405 nm.

[0218] When using ultraviolet light, light sources such as sunlight, chemical lamps, mercury lamps, metal halide lamps, or UV LEDs can be used.

[0219] 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.

[0220] From the viewpoint of improving the appearance of the resulting optically shaped article, the cumulative light intensity of ultraviolet irradiation is preferably 30 J or more and 200 J or less, more preferably 50 J or more and 150 J or less, even more preferably 70 J or more and 120 J or less, and even more preferably 90 J or more and 100 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.

[0221] The manufacturing method of the optical molded body in this embodiment may also include the following steps.

[0222] • Coating process: The process of applying the light-curable resin composition to the lower mold for molding.

[0223] • Upper mold setting process: The process of setting the upper mold for molding onto the UV-curable resin composition.

[0224] <Coating Process>

[0225] In the coating process, the photocurable resin composition is applied to the lower mold for molding. From the viewpoint of facilitating the application of the photocurable resin composition, the thickening process is preferably performed after the coating process.

[0226] <Upper mold setting process>

[0227] In the upper mold setting process, an upper mold for molding is set onto the photocurable resin composition. From the viewpoint of reducing leakage of the photocurable resin composition between the upper mold and the lower mold during upper mold setting, the upper mold setting process is preferably performed after the thickening process and before the curing process.

[0228] (Optical equipment)

[0229] 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).

[0230] 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.

[0231] 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.

[0232] Example

[0233] Hereinafter, this embodiment will be described in detail with reference to examples, etc. However, this embodiment is not limited in any way by the description in these examples.

[0234] First, the materials used in each example are shown.

[0235] Polymerizable compound: (meth)acrylate monomer (A)

[0236] Monofunctional (meth)acrylate monomer (A1): GM81HDA (dicyclopentyl methacrylate, manufactured by Guojing Chemical Co., Ltd.)

[0237] 2 or more functional (meth)acrylate monomers (A2)1: DDD (1,12-dodecanediol dimethacrylate, manufactured by Shin-Nakamura Chemical Industry Co., Ltd.)

[0238] 2-functional or higher (meth)acrylate monomers (A2)2:DCP (tricyclodecanediethanol dimethacrylate, manufactured by Shin-Nakamura Chemical Industry Co., Ltd.)

[0239] 2-functional or higher (meth)acrylate monomers (A2)3: A-DCP (tricyclodecanedimethyl diacrylate, manufactured by Shin-Nakamura Chemical Industry Co., Ltd.)

[0240] • Antioxidants (B)

[0241] 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)

[0242] 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)

[0243] Photopolymerization initiator (C)

[0244] Photopolymerization initiator 1: Photoradical polymerization initiator (1-hydroxycyclohexylphenyl ketone, manufactured by IGM Resins, product name: Omnirad 184)

[0245] Photopolymerization initiator 2: Photoradical polymerization initiator (2,4,6-trimethylbenzoyl diphenylphosphine oxide, manufactured by IGMresins, product name: Omnirad TPO H)

[0246] • Light stabilizer (D)

[0247] 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)

[0248] (Examples 1-5, Comparative Examples 1-4)

[0249] The components were combined in the manner shown in Table 1 to obtain a liquid photocurable resin composition. The units for the composition in Table 1 are parts by mass.

[0250] 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.

[0251] <Determination of absorbance at 405 nm>

[0252] Using the photocurable resin compositions of each example, the absorbance A at a wavelength of 405 nm was measured according to the following <Test Method>. 405 .

[0253] <Determination Method>

[0254] A sample was prepared by mixing a photocurable resin composition and isopropyl alcohol (manufactured by Tokyo Chemical Industry Co., Ltd., product name: Isopropyl Alcohol) in a mass ratio of 7:93 to dissolve the photocurable resin composition in the isopropyl alcohol. Next, the sample was placed in a sample cell with a 10 mm optical path length (material: ES quartz glass, optical path length 10 mm, optical path width 10 mm, type: two-sided transparent, product name: standard quartz cell for spectrophotometer (two-sided transparent)). According to the following <Absorbance Measurement Conditions>, light with a wavelength of 405 nm and an incident light intensity I0 was incident on the sample cell, and the transmitted light intensity I was measured. Then, the absorbance A at a wavelength of 405 nm was calculated using the following formula (4). 405 .

[0255] (4): A 405 =-log 10 (I / I0)

[0256] <Absorbance Measurement Conditions>

[0257] Measuring apparatus: Ultraviolet-Vis-NearInfrared Spectrophotometer (manufactured by Japan Spectrophotometer Co., Ltd., product name: V770)

[0258] Measurement method: Transmission method

[0259] Measurement wavelength: 405nm

[0260] Reference solution: Isopropyl alcohol (manufactured by Tokyo Chemical Industry Co., Ltd., product name: Isopropyl Alcohol)

[0261] Detectors: Photomultiplier tube, cooled PbS photoconductive element

[0262] <Evaluation of Surface Inhomogeneity>

[0263] Using the photocurable resin compositions of each example, optical molded articles were manufactured according to the <Preparation Conditions for Optical Molded Articles> below. The surface unevenness of the manufactured optical molded articles was evaluated according to the <Evaluation Method> below.

[0264] <Fabrication conditions for optical molded objects>

[0265] A 3.0mm thick, 50mm x 50mm silicone wafer (material: silicone rubber, hardness: 50 degrees) with a 35mm φ circular hole is placed on a 2.0mm thick, 50mm x 50mm single-sided mirror-finished SUS304 substrate (product name: SUS304-BA, manufactured by Standard Test Piece). After filling the circular hole portion of the silicone wafer with a photocurable resin composition, a 0.7mm thick, 50mm x 50mm alkali-free glass (product name: JIS R 3202 lightly chamfered glass plate, manufactured by Test Piece) is further placed on it. At this time, it is confirmed that no air bubbles are introduced. Hereinafter, the laminate in which the silicone wafer is placed on the SUS304 substrate and the circular hole portion of the silicone wafer is filled with a photocurable resin composition, and then the alkali-free glass is further placed on it, is sometimes referred to as a laminate.

[0266] 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 110mW for 1 minute from above the alkali-free glass. After 30 seconds of irradiation, the laminate was irradiated with 405nm LED light at 810mW for 2 minutes. Following 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 SUS304 substrate, silicone wafer, and alkali-free glass to obtain the optically molded body.

[0267] It should be noted that the illuminance of the LED light was measured using a 405nm illuminance meter (USHIO, product name: UIT150).

[0268] <Evaluation Methods>

[0269] A 2mm thick, 100mm x 100mm alkali-free glass (manufactured by Test Piece Co., Ltd., JIS R 3202 (glass plate) silk-faced) was placed on white paper (manufactured by Tanosee PPC Paper Type FW A4 PPCFW-A4). Furthermore, the fabricated optical model was placed on the alkali-free glass. In this state, the optical model was observed under white LED illumination with an intensity of 300 lux or more and 500 lux or less. Specifically, the pattern projected onto the white paper due to the surface unevenness of the optical model was observed.

[0270] The proportion of the pattern projected onto the white paper due to surface unevenness of the optical molded body to the surface of the optical molded body in contact with the SUS304 substrate is defined as proportion R. Cases where proportion R is 0% or more but less than 2% are defined as A, cases where it is 2% or more but less than 20% are defined as B, and cases where it is 20% or more but less than 100% are defined as C.

[0271] [Table 1]

[0272]

[0273] This application claims priority based on Japanese Patent Application No. 2024-012816, filed on January 31, 2024, the entire contents of which are incorporated herein by reference.

Claims

1. A photocurable resin composition, which is a photocurable resin composition suitable for use in optically molded articles, wherein the absorbance A of the photocurable resin composition at a wavelength of 405 nm is measured according to the following <Measurement Method>. 405 Below 0.300 <Determination Method> A sample was prepared by dissolving the photocurable resin composition in isopropanol at a mass ratio of 7:

93. The sample was then placed in a sample cell with an optical path length of 10 mm. The transmitted light intensity I was measured when light with a wavelength of 405 nm and an incident light intensity I0 was incident on the sample cell. The absorbance A at a wavelength of 405 nm was calculated using the following formula (1). 405 , (1):A 405 =-log 10 (I / I0)。 2. The photocurable resin composition according to claim 1, wherein, The absorbance A 405 It is above 0.

010.

3. The photocurable resin composition according to claim 1 or 2, comprising (meth)acrylate monomer.

4. The photocurable resin composition according to claim 3, wherein, The (meth)acrylate monomer comprises 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 3 or 4, wherein, The (meth)acrylate monomer comprises a (meth)acrylate monomer having an alicyclic backbone.

6. The photocurable resin composition according to claim 5, wherein, The (meth)acrylate monomer having an alicyclic skeleton comprises one or more skeletons selected from the group consisting of adamantane skeleton, norbornene skeleton and dicyclopentadiene skeleton.

7. The photocurable resin composition according to claim 5 or 6, wherein, When the total content of the (meth)acrylate monomer is set to 100 parts by mass, the content of the (meth)acrylate monomer having an alicyclic skeleton is 30 parts by mass or more and 100 parts by mass or less.

8. The photocurable resin composition according to any one of claims 3 to 7, wherein, The (meth)acrylate monomer comprises a (meth)acrylate monomer having a straight-chain hydrocarbon backbone.

9. The photocurable resin composition according to any one of claims 1 to 8, further comprising a photopolymerization initiator.

10. The photocurable resin composition according to claim 9, wherein, The photopolymerization initiator includes a photoradical polymerization initiator.

11. The photocurable resin composition according to claim 9 or 10, wherein, When the total content of (meth)acrylate monomer is set to 100 parts by mass, the content of the photopolymerization initiator is 0.10 parts by mass or more and 10 parts by mass or less.

12. The photocurable resin composition according to any one of claims 1 to 11, further comprising an antioxidant.

13. The photocurable resin composition according to claim 12, wherein, When the total content of (meth)acrylate monomer is set to 100 parts by mass, the content of the antioxidant is 0.010 parts by mass or more and 10 parts by mass or less.

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

15. The photocurable resin composition according to claim 14, wherein, When the total content of (meth)acrylate monomer is set to 100 parts by mass, the content of the light stabilizer is 0.010 parts by mass or more and 5 parts by mass or less.

16. The photocurable resin composition according to any one of claims 1 to 15, wherein, When the total amount of the photocurable resin composition is set to 100% by mass, the content of (meth)acrylate monomer is 80% by mass or more and less than 100% by mass.

17. The photocurable resin composition according to any one of claims 1 to 16, which can be used in casting.

18. An optically molded article comprising a cured product of the photocurable resin composition according to any one of claims 1 to 17.

19. The optically shaped article according to claim 18, wherein, The optical molding includes a lens.

20. The optically shaped article according to claim 19, 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.

21. The optically shaped article according to any one of claims 18 to 20, wherein, The maximum thickness is less than 20.0 mm.

22. The optically shaped article according to any one of claims 18 to 21, wherein, The maximum thickness of the optically shaped body is 1.0 mm or more.

23. An optical device comprising the optical molding body according to any one of claims 18 to 22.

24. A method for manufacturing an optically shaped object, comprising: In the thickening process, an irradiation device with a light source peak at a wavelength above 360 ​​nm and below 410 nm is used to irradiate the photocurable resin composition, thereby increasing the viscosity of the photocurable resin composition; and In the curing process, after the thickening process, the photocurable resin composition is irradiated with light using an irradiation device having a light source peak at a wavelength of 360 nm or higher and 410 nm or lower, thereby curing the photocurable resin composition.

25. The method for manufacturing an optically shaped object according to claim 24, wherein, After the thickening process and before the curing process, there is also an upper mold setting process, which involves setting an upper mold for molding on the photocurable resin composition.

26. The method for manufacturing an optically shaped object according to claim 24 or 25, wherein, It also includes a coating process of applying the photocurable resin composition to a lower mold for molding. The thickening process is performed after the coating process.

27. The method for manufacturing an optically shaped article according to any one of claims 24 to 26, wherein, The thickening process includes: irradiating the photocurable resin composition with light at an intensity of 90mW to 130mW using an irradiation device having a light source peak at a wavelength of 360nm or higher and 410nm or lower.

28. The method for manufacturing an optically shaped article according to any one of claims 24 to 27, wherein, The thickening process includes: irradiating the photocurable resin composition with light using an irradiation device having a light source peak at a wavelength of 360 nm or higher and 410 nm or lower for an irradiation time of 1 second or higher and 300 seconds or lower.

29. The method for manufacturing an optically shaped article according to any one of claims 24 to 28, wherein, The thickening process includes: irradiating the photocurable resin composition with light using an irradiation device having a light source peak at a wavelength of 360 nm or higher and 410 nm or lower, with a cumulative light intensity of 50 mJ or higher and 20.0 J or lower.

30. The method for manufacturing an optically shaped article according to any one of claims 24 to 29, wherein, In the thickening process, the thickness of the photocurable resin composition is less than 15.0 mm.

31. The method for manufacturing an optically shaped article according to any one of claims 24 to 30, wherein, The photocurable resin composition comprises any one of the photocurable resin compositions according to claims 1 to 17.

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