Optical molded article

Abstract

To provide an optical molding having high shape stability and optical performance stability even after storage in a high temperature and high humidity environment.SOLUTION: An optical molded article comprising a resin substrate, a moisture-proof layer, and an optical functional layer in this order, wherein the moisture-proof layer is an amorphous film containing aluminum, silicon, oxygen, and carbon, and the optical functional layer is an antireflection layer and / or a partial reflection film.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to an optical molded article. [Background technology]

[0002] Traditionally, glass has been used for optical molded products such as lenses and prisms, but in recent years, resin materials have begun to be used due to the need for greater design freedom, such as lighter and smaller sizes and aspherical lenses. Furthermore, along with the dramatic improvement in the performance of optical products in recent years, such as virtual reality (VR) and augmented reality (AR), the precision of the optical design inside optical products has also increased. Therefore, regardless of whether they are made of glass or resin, the requirements for stability of optical performance, such as shape stability and refractive index, for optical molded products are becoming increasingly strict, not only at room temperature but also in harsh environments such as high-temperature and high-humidity environments.

[0003] However, resin materials have the problem that their optical properties, such as product shape and refractive index, change due to moisture absorption. To solve this problem, attempts have been made to form a moisture-proof coating on the surface of an optical molded product made of a resin substrate. Patent Document 1 discloses a technology relating to an optical molded product whose surface in contact with the outside air is covered with a polycrystalline moisture-proof coating. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2006-146025 Summary of the Invention [Problem to be solved by the invention]

[0005] As a result of the inventors' investigations, it has become clear that optical molded articles containing moisture-proof coatings obtained by the above-mentioned conventional methods do not have sufficient moisture-proof properties and are unable to suppress performance changes due to moisture absorption during storage in a high-temperature, high-humidity environment.

[0006] Therefore, the present invention has been made in consideration of the above problems, and aims to provide an optical molded product that has high shape stability and optical performance stability even after storage in a high-temperature, high-humidity environment. [Means for solving the problem]

[0007] That is, the present invention is as follows. [1] An optical molded article including a resin substrate, a moisture-proof layer, and an optical functional layer in this order, the moisture-proof layer is an amorphous film containing aluminum, silicon, oxygen, and carbon; The optical functional layer is an anti-reflection film and / or a partially reflective film. An optical molded article characterized by: [2] The optical molded article according to [1], wherein the moisture-proof layer further contains nitrogen. [3] The moisture-proof layer is The optical molded article according to [1] or [2], characterized in that it comprises an aluminum-based composition layer containing aluminum, oxygen, and carbon. [4] In the moisture-proof layer, The aluminum-based composition layer includes a layer having a carbon content of 0.1 to 10 atomic %. The optical molded article according to [3], [5] In the moisture-proof layer, the total content of aluminum, oxygen, and carbon in the aluminum-based composition layer is 70 atomic % or more; The optical molded article according to [3] or [5], [6] The moisture-proof layer is a silicon-based composition layer containing silicon, oxygen, and nitrogen; The molded article for optical use according to any one of [1] to [5], characterized in that: [7] In the moisture-proof layer, The silicon-based composition layer includes a layer having a nitrogen content of 0.1 to 10 atomic %. The optical molded article according to [6], [8] In the moisture-proof layer, The total content of silicon, oxygen, and nitrogen in the silicon-based composition layer is 70 atomic % or more. The optical molded article according to [6] or [7], [9] The moisture-proof layer is The aluminum-based composition layer and the silicon-based composition layer are alternately laminated. The optical molded article according to any one of [6] to [8].

[10] The optical molded body according to [9], characterized in that in the moisture-proof layer, the ratio of the total thickness of the aluminum-based composition layers to the total thickness of the silicon-based composition layers (aluminum-based composition layers:silicon-based composition layers) is 1:4 to 4:1.

[11] The optical molded article according to

[10] , wherein the total number of layers in the alternating laminate structure is 6 or more.

[12] The optical molded article according to

[11] , wherein the moisture-proof layer covers the entire surface of the molded article and has a film thickness distribution of 10% or less.

[13] The optical molded article according to any one of [1] to

[12] , characterized in that the resin substrate is formed from one or more resins selected from the group consisting of methacrylic resins, polyester resins, carbonate resins, norbornene resins, and modified norbornene resins. [Effects of the Invention]

[0008] According to the present invention, it is possible to provide an optical molded article that has sufficient moisture-proofing properties and exhibits high stability of shape and optical performance even after storage in a high-temperature, high-humidity environment. DETAILED DESCRIPTION OF THE INVENTION

[0009] Below, we will explain in detail the form for implementing the present invention (hereinafter referred to as the ``present embodiment''), but the present invention is not limited to the following description and can be implemented in various modifications within the scope of its gist.

[0010] <Optical molded body> The optical molded article of this embodiment includes a resin substrate, a moisture-proof layer, and an optically functional layer, in this order. Here, "in this order" refers to the order of lamination (i.e., "laminated in this order"). The optical molded article of this embodiment may also include additional layers other than those described above. Examples of additional layers include functional layers such as an antifouling layer, a water-repellent layer, an oil-repellent layer, and a hard coat layer, as well as black coating layers for suppressing light incidence from the side, pretreatment layers for improving adhesion between each layer, and primer layers. The additional layers may be located anywhere, such as between the resin substrate and the moisture-proof layer, between the moisture-proof layer and the optically functional layer, or on the optically functional layer, as long as the effects of this embodiment are not impaired.

[0011] <Resin substrate> The resin substrate of this embodiment may be a resin molded body.

[0012] The shape of the resin substrate is not particularly limited, and various shapes such as a film / sheet, a flat plate, a curved surface, a bowl, a lens, a block, a sphere, a rod, a column, a cylinder, a tube, a fiber, etc. may be used. In addition to the above shapes, shapes having fine patterns formed on the surface may also be used. As a more specific example, the shape of the substrate of this embodiment may be a lens, a prism, a light guide, or a diffraction grating.

[0013] The method for producing the resin substrate is not particularly limited, and known methods can be used. Examples include injection molding, extrusion molding, compression molding, injection compression molding, vacuum molding, pressure molding, blow molding, cast polymerization, etc. Furthermore, the molded article obtained by the above-mentioned production methods may be further subjected to grinding or turning.

[0014] The size of the resin substrate is not particularly limited, but from the viewpoints of ease of handling in the film-forming step and productivity, it is preferably φ1 mm or more, more preferably φ5 mm or more, even more preferably φ10 mm or more, still more preferably φ20 mm or more, particularly preferably φ30 mm or more, and is preferably φ300 mm or less, more preferably φ200 mm or less, even more preferably φ150 mm or less, still more preferably φ120 mm or less, particularly preferably φ100 mm or less. The size may be the size of one surface of the substrate, or the diameter in the case of a substantially circular shape (for example, the length of the major axis in the case of an ellipse).

[0015] The thickness of the resin substrate is preferably 0.1 mm or more, more preferably 0.2 mm or more, even more preferably 0.3 mm or more, particularly preferably 0.5 mm or more, and preferably 100 mm or less, more preferably 50 mm or less, even more preferably 30 mm or less, and particularly preferably 25 mm or less. Here, thickness refers to the distance between the main surface of the resin substrate and its opposing surface. If the resin substrate is lens-shaped, the maximum distance in the optical axis direction between the light incident surface and its opposing surface is used. If the resin substrate is prism-shaped, the maximum distance between the light incident surface and its opposite surface (if there are multiple opposite surfaces, the farthest surface may be selected) or the distance between the bases of a polygonal prism is used, whichever is smaller. If the resin substrate is cylindrical or elliptical, the minimum outer diameter or the distance between the bases is used. In the case of a substrate in which light is incident laterally, such as a light guide plate, the maximum distance refers to the maximum distance between the light exit surface and its opposite surface.

[0016] The specific surface area of ​​the resin substrate is 0.1 mm when there is a fine shape on the surface of the substrate. -1 More than 0.3mm is preferable. -1 More preferably, 0.5 mm or more -1 Above is especially preferable, 10 mm -1 Less than 8mm is preferable -1 Less than 5mm is more preferable -1 The following is particularly preferred: When there is no fine shape on the surface of the substrate, the surface area is 0.01 mm-1 More than 0.1mm is preferable. -1 More preferably, 0.3 mm or more -1 Above is especially preferable, 5mm -1 Less than 4mm is preferable -1 Less than 3mm is more preferable -1 The following is particularly preferred. A specific surface area within this range is preferred from the viewpoint of the balance between the surface functionality as an optical element and the change in shape of the molded body due to the penetration of moisture from the surface of the molded body. Here, the specific surface area is the surface area per unit volume of the substrate.

[0017] The resin substrate may be a thermoplastic resin.

[0018] Examples of thermoplastic resins include methacrylic resins, polycarbonate resins, polyester resins, aramid resins, polyolefin resins, modified polyolefin resins, modified norbornene resins, norbornene resins, cyclic block copolymers (CBC), triacetyl cellulose (TAC), polyphenylene sulfide (PPS), polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polyethylene naphthalate (PEN), polyoxymethylene (POM), polyether ether ketone (PEEK), ABS resins, polyamides, and polyimides. Among these, since excellent transparency is desirable for optical applications, methacrylic resins, polycarbonate resins, polyester resins, modified norbornene resins, TAC, PET, and PEN are preferred, and any one selected from the group consisting of methacrylic resins, polyester resins, carbonate resins, modified norbornene resins, TAC, and PET is more preferred, and any one selected from the group consisting of methacrylic resins, polyester resins, carbonate resins, and modified norbornene resins is even more preferred, with methacrylic resins being particularly preferred from the viewpoint of low birefringence.

[0019] The thermoplastic resins may be used alone or in combination of two or more. Optionally, additives may be blended. The additives are not particularly limited as long as they can exhibit the effects of the present invention, and may be appropriately selected depending on the purpose.

[0020] (Methacrylic resin) When a methacrylic resin is used as the thermoplastic resin, a homopolymer of methyl methacrylate (MMA) or a copolymer of MMA and another monomer can be used. From the viewpoints of thermal stability, heat resistance, and low birefringence, it is preferable to use a copolymer, and it is more preferable to use a random copolymer. The composition of the methacrylic resin is not particularly limited, but may include 50 to 100 wt% of methacrylic acid ester monomer units (A), 0 to 30 wt% of structural units (B) having a ring structure in the main chain and / or side chain, and 0 to 20 wt% of other vinyl monomer units (C) copolymerizable with the methacrylic acid ester monomers.

[0021] Examples of the methacrylic acid ester monomer unit (A) include, but are not limited to, methyl methacrylate, ethyl methacrylate, n-propyl methacrylate, isopropyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, t-butyl methacrylate, 2-ethylhexyl methacrylate, cyclopentyl methacrylate, cyclohexyl methacrylate, cyclooctyl methacrylate, tricyclodecyl methacrylate, isobornyl methacrylate, phenyl methacrylate, benzyl methacrylate, 1-phenylethyl methacrylate, 2-phenoxyethyl methacrylate, 3-phenylpropyl methacrylate, and 2,4,6-tribromophenyl methacrylate. The methacrylic acid ester monomer is preferably methyl methacrylate, ethyl methacrylate, cyclohexyl methacrylate, phenyl methacrylate, or benzyl methacrylate from the viewpoint of heat resistance, optical properties, and weather resistance of the resulting methacrylic resin, and is preferably methyl methacrylate or benzyl methacrylate from the viewpoint of availability, etc. The methacrylic acid ester monomers may be used alone or in combination of two or more.

[0022] By appropriately adjusting the ratio of the methacrylic acid ester monomer units (A) of the methacrylic resin to the structural units (B) having a ring structure in the main chain and / or side chain and the other vinyl-based monomer units (C) copolymerizable with the methacrylic acid ester monomers (described later), the resin-made optical element of this embodiment can be provided with sufficient thermal stability and heat resistance, a good hue, low moisture absorption, and reduced birefringence caused by orientation during molding or residual stress. From these perspectives, the content of the methacrylic acid ester monomer units (A) is preferably 50 wt% or more, more preferably 55 wt% or more, and even more preferably 60 wt% based on 100 wt% of the methacrylic resin. It is also preferably 100 wt% or less, more preferably 95 wt% or less, and even more preferably 90 wt% or less.

[0023] The structural unit (B) having a ring structure in the main chain and / or side chain is not limited to the following, but it is preferable that the structural unit (B) has at least one structural unit selected from the group consisting of a maleimide structural unit (B-1), a glutaric anhydride structural unit (B-2), a glutarimide structural unit (B-3), a lactone ring structural unit (B-4), an acid anhydride structural unit (B-5), an aromatic structural unit (B-6), and an alicyclic structural unit (B-7). The structural unit (B) having a ring structure in the main chain and / or side chain may be used alone or in combination of two or more kinds.

[0024] As the maleimide structural unit (B-1) constituting the methacrylic resin, a structural unit represented by the following general formula (1) is preferably used. [ka] In the general formula (1), R 1represents any one selected from the group consisting of a hydrogen atom, an alkyl group having 1 to 14 carbon atoms, a cycloalkyl group having 3 to 14 carbon atoms, an alkoxy group having 1 to 14 carbon atoms, an arylalkyl group having 7 to 14 carbon atoms, and an aryl group having 6 to 14 carbon atoms, and the alkyl group, cycloalkyl group, alkoxy group, arylalkyl group, and aryl group may have a substituent on a carbon atom.

[0025] Monomers for forming the maleimide-based structural unit (B-1) include, but are not limited to, maleimides such as N-methylmaleimide, N-ethylmaleimide, Nn-propylmaleimide, N-isopropylmaleimide, Nn-butylmaleimide, N-isobutylmaleimide, Nt-butylmaleimide, Nn-pentylmaleimide, Nn-hexylmaleimide, Nn-heptylmaleimide, Nn-octylmaleimide, and N-laurylmaleimide. N-Alkyl group-substituted maleimides such as N-cyclopentylmaleimide, N-cyclohexylmaleimide, 1-cyclohexyl-3-methyl-1H-pyrrole-2,5-dione, 1-cyclohexyl-3,4-dimethyl-1H-pyrrole-2,5-dione, 1-cyclohexyl-3-phenyl-1H-pyrrole-2,5-dione, and 1-cyclohexyl-3,4-diphenyl-1H-pyrrole-2,5-dione; N-cycloalkyl group-substituted maleimides such as N-cyclopentylmaleimide, N-cyclohexylmaleimide, 1-cyclohexyl-3-methyl-1H-pyrrole-2,5-dione, 1-cyclohexyl-3,4-dimethyl-1H-pyrrole-2,5-dione, and 1-cyclohexyl-3,4-diphenyl-1H-pyrrole-2,5-dione; N-phenylmaleimide, N-benzylmaleimide, N-(2-chlorophenyl)maleimide, N-(4-chlorophenyl)maleimide, N-(4-bromophenyl)maleimide, N-(2-methylphenyl)maleimide, N-(2,6-dimethylphenyl)maleimide, N-(2-ethylphenyl)maleimide, N-(2-methoxyphenyl)maleimide, N-(2-nitrophenyl)maleimide, N-(2,4,6-trimethylphenyl)maleimide, N-(4 N-aryl group-substituted maleimides such as N-(2,4,6-tribromophenyl)maleimide, N-naphthylmaleimide, N-anthracenylmaleimide, 3-methyl-1-phenyl-1H-pyrrole-2,5-dione, 3,4-dimethyl-1-phenyl-1H-pyrrole-2,5-dione, 1,3-diphenyl-1H-pyrrole-2,5-dione, and 1,3,4-triphenyl-1H-pyrrole-2,5-dione are examples of maleimides usable in the present invention. The maleimide structural unit (B-1) may be used alone or in combination of two or more.

[0026] The content of the maleimide structural unit (B-1) is preferably 1 to 70 mass %, more preferably 3 to 60 mass %, and even more preferably 5 to 40 mass %, based on 100 mass % of the methacrylic resin. When the content of the maleimide structural unit (B-1) is within the above range, a resin having good moldability, heat resistance, optical properties, low birefringence, and low water absorption can be obtained, which is preferable.

[0027] The methacrylic resin containing the maleimide structural unit (B-1) may further contain, as necessary, structural units derived from other monomers copolymerizable with the methacrylic acid ester monomer unit (A) and the maleimide structural unit (B-1), such as aromatic vinyl monomer units and unsaturated nitrile monomer units. The aromatic vinyl monomer is not particularly limited, but examples thereof include styrene and α-methylstyrene, with styrene being preferred. The unsaturated nitrile monomer is not particularly limited, but may be acrylonitrile, methacrylonitrile, Examples of the acrylonitrile include acrylonitrile and ethacrylonitrile, with acrylonitrile being preferred.

[0028] As the glutaric anhydride structural unit (B-2) constituting the methacrylic resin, a structural unit represented by the following general formula (2) is preferably used. [ka] In the general formula (2), R 1 and R 2 are each independently a hydrogen atom or a substituted or unsubstituted alkyl group having 1 to 6 carbon atoms, and the alkyl group may be substituted with a hydroxyl group.

[0029] The method for forming the glutaric anhydride structural unit (B-2) is not particularly limited, and examples thereof include a method in which a monomer having a structure represented by the following general formula (3) is copolymerized with a monomer constituting the methacrylic acid ester monomer unit (A) described above, followed by cyclization by heat treatment in the presence / absence of a catalyst. [ka] In the general formula (3), R 1 represents a hydrogen atom or a substituted or unsubstituted alkyl group having 1 to 6 carbon atoms, and the alkyl group may be substituted with a hydroxyl group. R 2 represents a hydrogen atom or a t-butyl group.

[0030] Furthermore, the monomer having the structure represented by general formula (3) may remain unreacted in the methacrylic resin, as long as the effects of the present invention can be achieved.

[0031] The glutarimide structural unit (B-3) constituting the methacrylic resin may be formed after the resin polymerization. As the (B-3) structural unit, a structural unit represented by the following general formula (4) is preferably used. [ka] In the general formula (4), R 1 and R 2 are each independently a hydrogen atom or a substituted or unsubstituted alkyl group having 1 to 6 carbon atoms, and the alkyl group may be substituted with a hydroxyl group. Also, R 3 represents any one selected from the group consisting of a hydrogen atom, a substituted or unsubstituted alkyl group having 1 to 6 carbon atoms, a cycloalkyl group having 6 to 14 carbon atoms, and a substituted or unsubstituted aryl group having 6 to 18 carbon atoms. Particularly preferably, R 1 , R 2 , and R 3 are all methyl groups.

[0032] The glutarimide structural unit (B-3) may be used alone or in combination of two or more.

[0033] The content of the glutarimide structural unit (B-3) is preferably 1 to 70% by mass, more preferably 3 to 60% by mass, based on 100% by mass of the methacrylic resin. A content of the glutarimide structural unit (B-3) within the above range is preferred because it results in a resin with excellent moldability, heat resistance, optical properties, and low birefringence. The content of the glutarimide structural unit (B-3) can be calculated, for example, by the method described in paragraphs

[0136] and

[0137] of WO 2015 / 098096.

[0034] The methacrylic resin containing the glutarimide structural unit (B-3) may further contain an aromatic vinyl monomer unit, if necessary. The aromatic vinyl monomer is not particularly limited, but examples thereof include styrene and α-methylstyrene, with styrene being preferred.

[0035] The lactone ring structural unit (B-4) constituting the methacrylic resin may be formed after the resin polymerization. As the (B-4) structural unit, a structural unit represented by the following general formula (5) is preferably used. [ka] In the general formula (5), R 1 , R 2 , and R 3 are each independently a hydrogen atom or an organic group having a carbon number of 1 to 20. The organic group may contain an oxygen atom. The lactone ring structural unit (B-4) may be used alone or in combination of two or more.

[0036] The lactone ring structural unit can be formed, for example, by copolymerizing an acrylic acid monomer having a hydroxy group with a methacrylic acid ester monomer such as methyl methacrylate to introduce a hydroxy group and an ester group or a carboxyl group into the molecular chain, and then causing dealcoholization (esterification) or dehydration condensation (hereinafter also referred to as a "cyclization condensation reaction") between the hydroxy group and the ester group or the carboxyl group.

[0037] Examples of the acrylic acid monomer having a hydroxy group to be used in the polymerization include 2-(hydroxymethyl)acrylic acid, 2-(hydroxyethyl)acrylic acid, alkyl 2-(hydroxymethyl)acrylate, and alkyl 2-(hydroxyethyl)acrylate, and preferred are methyl 2-(hydroxymethyl)acrylate and ethyl 2-(hydroxymethyl)acrylate.

[0038] The content of the lactone ring structural unit (B-4) is preferably 1 to 70 mass %, more preferably 3 to 60 mass %, and even more preferably 5 to 40 mass %, based on 100 mass % of the methacrylic resin. When the content of the lactone ring structural unit (B-4) is within the above range, a resin having good moldability, heat resistance, optical properties, low birefringence, solvent resistance, and surface hardness can be obtained, which is preferable.

[0039] The methacrylic resin containing the lactone ring structural unit (B-4) may further contain an aromatic vinyl monomer unit, if necessary. The aromatic vinyl monomer is not particularly limited, but examples thereof include styrene and α-methylstyrene, with styrene being preferred.

[0040] The acid anhydride structural unit (B-5) constituting the methacrylic resin can be formed using, for example, an acid anhydride such as maleic anhydride, a half ester of the acid anhydride with a linear or branched alcohol having 1 to 20 carbon atoms, or an α,β-ethylenically unsaturated carboxylic acid.

[0041] The content of the acid anhydride structural unit (B-5) is preferably 1 to 70% by mass, more preferably 3 to 60% by mass, and even more preferably 5 to 40% by mass, based on 100% by mass of the methacrylic resin. When the content of the acid anhydride structural unit (B-5) is within the above range, a resin having good moldability, heat resistance, optical properties, and low birefringence can be obtained, which is preferable.

[0042] The methacrylic resin containing the acid anhydride structural unit (B-5) may further contain structural units derived from other monomers copolymerizable with the methacrylic acid ester monomer unit (A) and the acid anhydride structural unit (B-5), such as aromatic vinyl monomer units and unsaturated nitrile monomer units, as necessary.

[0043] The aromatic vinyl monomer is not particularly limited, but examples thereof include styrene and α-methylstyrene, with styrene being preferred. The unsaturated nitrile monomer is not particularly limited, but examples thereof include acrylonitrile, methacrylonitrile, and ethacrylonitrile, with acrylonitrile being preferred.

[0044] As the aromatic structural unit (B-6) constituting the methacrylic resin, a structure represented by the following general formula (6) is preferably used. [ka] In the general formula (6), R 1 represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms, and the alkyl group may be substituted with, for example, a hydroxyl group. R 2 is any one selected from the group consisting of a hydrogen atom, an alkyl group having 1 to 12 carbon atoms, an alkoxy group having 1 to 12 carbon atoms, an aryl group having 6 to 8 carbon atoms, and an aryloxy group having 6 to 8 carbon atoms; R 2 may all be the same group or different groups. 2 In general formula (6), n represents an integer of 0 to 5.

[0045] Specific examples of the monomer represented by the general formula (6) include, but are not limited to, styrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, 2,4-dimethylstyrene, 2,5-dimethylstyrene, 3,4-dimethylstyrene, 3,5-dimethylstyrene, p-ethylstyrene, m-ethylstyrene, o-ethylstyrene, p-tert-butylstyrene, 1-vinylnaphthalene, 2-vinylnaphthalene, 1,1-diphenylethylene, isopropenylbenzene (α-methylstyrene), isopropenyltoluene, isopropenylethylbenzene, isopropenylpropylbenzene, isopropenylbutylbenzene, isopropenylpentylbenzene, isopropenylhexylbenzene, and isopropenyloctylbenzene. Of the above, styrene and α-methylstyrene are preferred, and styrene is more preferred from the viewpoints of imparting fluidity and reducing unreacted monomers by improving the polymerization conversion rate.

[0046] The content of the aromatic structural unit (B-6) is 100% by mass of the methacrylic resin. The content of the aromatic structural unit (B-6) in the above range is preferably from 1 to 30% by mass, more preferably from 3 to 25% by mass, and even more preferably from 5 to 20% by mass. When the content of the aromatic structural unit (B-6) is in the above range, a resin having good moldability, heat resistance, optical properties, and low birefringence can be obtained, which is preferable.

[0047] As the alicyclic structural unit (B-7) constituting the methacrylic resin, a saturated alicyclic hydrocarbon compound having a vinyl group is preferably used.

[0048] The number of carbon atoms constituting the alicyclic structure is usually 4 to 30, preferably 5 to 20, more preferably 5 to 15, and most preferably 6, from the viewpoints of mechanical strength, heat resistance, and moldability.

[0049] Specific examples of such monomers include vinylcyclohexane, isopropenylcyclohexane, 4-methylisopropenylcyclohexane, 3-methylisopropenylcyclohexane, 4-methylvinylcyclohexane, and 3-methylvinylcyclohexane.

[0050] Such structural units can be formed, for example, by copolymerizing a vinylcycloalkane monomer with a methacrylic acid ester monomer such as methyl methacrylate. Alternatively, they can be formed by copolymerizing a vinylcycloalkene monomer or an aromatic vinyl monomer with a methacrylic acid ester monomer such as methyl methacrylate to introduce an unsaturated alicyclic group or an aromatic ring into the molecular chain, followed by hydrogenation. In the hydrogenation reaction, all carbon-carbon unsaturated bonds, including aromatic rings, are hydrogenated, preferably 80% or more, more preferably 95% or more, and even more preferably 99 to 100%.

[0051] Examples of the vinylcycloalkene monomer used in the polymerization include 4-vinylcyclohexene, 4-isopropenylcyclohexene, 1-methyl-4-vinylcyclohexene, 2-methyl-4-vinylcyclohexene, 1-methyl-4-isopropenylcyclohexene, and 2-methyl-4-isopropenylcyclohexene.

[0052] Examples of aromatic vinyl monomers used in the polymerization include styrene, α-methylstyrene, α-ethylstyrene, α-propylstyrene, α-isopropylstyrene, α-t-butylstyrene, 2-methylstyrene, 3-methylstyrene, 4-methylstyrene, 2,4-diisopropylstyrene, 2,4-dimethylstyrene, 4-t-butylstyrene, 5-t-butyl-2-methylstyrene, 4-monochlorostyrene, dichlorostyrene, 4-monofluorostyrene, and 4-phenylstyrene.

[0053] The content of the alicyclic structural unit (B-7) is preferably 1 to 70 mass%, more preferably 3 to 60 mass%, and even more preferably 5 to 40 mass%, based on 100 mass% of the methacrylic resin. When the content of the alicyclic structural unit (B-7) is within the above range, a resin having good moldability, heat resistance, optical properties, and low birefringence can be obtained, which is preferable.

[0054] Other vinyl monomer units (C) copolymerizable with methacrylate monomer units include acrylate monomer units (C-1), vinyl cyanide monomer units (C- 2), and other monomer units (C-3). The other vinyl-based monomer units (C) copolymerizable with the methacrylic acid ester monomer may be used alone or in combination of two or more.

[0055] The (C) monomer unit can be selected from an appropriate material depending on the properties required of the methacrylic resin of this embodiment. When properties such as thermal stability, fluidity, mechanical properties, and chemical resistance are particularly required, at least one selected from the group consisting of acrylic ester monomer units (C-1) and vinyl cyanide monomer units (C-2) is preferred.

[0056] As the acrylate structural unit (C-1) constituting the methacrylic resin, a structural unit represented by the following general formula (7) is preferably used. [ka] In the general formula (7), R 1 represents a hydrogen atom or an alkoxy group having 1 to 12 carbon atoms, and R 2 represents an alkyl group having 1 to 18 carbon atoms.

[0057] As a monomer for forming the acrylic acid ester monomer unit (C-1), from the viewpoint of improving the weather resistance, heat resistance, fluidity, and thermal stability of the methacrylic resin of this embodiment, methyl acrylate, ethyl acrylate, n-propyl acrylate, n-butyl acrylate, sec-butyl acrylate, 2-ethylhexyl acrylate, cyclohexyl acrylate, phenyl acrylate, and the like are preferred, and methyl acrylate, ethyl acrylate, and n-butyl acrylate are more preferred, and from the viewpoint of easy availability, methyl acrylate and ethyl acrylate are even more preferred. The acrylic acid ester monomer unit (C-1) may be used alone or in combination of two or more kinds.

[0058] When the acrylic acid ester monomer unit (C-1) is used, its content is preferably 5% by mass or less, and more preferably 3% by mass or less, when the total amount of the (A) monomer unit and the (B) structural unit is taken as 100% by mass, from the viewpoints of heat resistance and thermal stability.

[0059] The monomer forming the vinyl cyanide monomer unit (C-2) constituting the methacrylic resin is not particularly limited, but examples thereof include acrylonitrile, methacrylonitrile, vinylidene cyanide, etc., and among these, acrylonitrile is preferred from the viewpoints of availability and chemical resistance. The vinyl cyanide monomer unit (C-2) may be used alone or in combination of two or more kinds.

[0060] When the vinyl cyanide monomer unit (C-2) is used, its content is preferably 15% by mass or less, more preferably 12% by mass or less, and even more preferably 10% by mass or less, when the total amount of the monomer unit (A) and the structural unit (B) is taken as 100% by mass, from the viewpoint of maintaining solvent resistance and heat resistance.

[0061] The monomer forming the monomer unit (C-3) other than (C-1) and (C-2) constituting the methacrylic resin is not particularly limited, and examples thereof include amides such as acrylamide and methacrylamide; ethylene glycol di(meth)acrylate, diethylene glycol di(meth)acrylate, triethylene glycol di(meth)acrylate, tetraethylene glycol di(meth)acrylate, and other ethylene glycol or oligomers thereof, both terminal hydroxyl groups of which are esterified with acrylic acid or methacrylic acid; neopentyl glycol di(meth)acrylate, di(meth)acrylate, and other ethylene glycol di(meth)acrylates, wherein two alcohol hydroxyl groups are esterified with acrylic acid or methacrylic acid; trimethylolpropane, pentaerythritol, and other polyhydric alcohol derivatives, esterified with acrylic acid or methacrylic acid; and polyfunctional monomers such as divinylbenzene.

[0062] The content of the other vinyl monomer units (C) copolymerizable with the methacrylic acid ester monomer is 0 to 20% by mass, preferably 0 to 18% by mass, and more preferably 0 to 15% by mass, based on 100% by mass of the methacrylic resin, from the viewpoint of enhancing the effect of the structural units (B) in imparting heat resistance. In particular, when a crosslinkable polyfunctional (meth)acrylate having a plurality of reactive double bonds is used as the (C) monomer unit, the content of the (C) monomer unit is preferably 0.5% by mass or less, more preferably 0.3% by mass or less, and even more preferably 0.2% by mass or less, from the viewpoint of the fluidity of the polymer.

[0063] The stereoregularity of the methacrylic resin is not particularly limited to the triad notation syndiotacticity (rr) and atacticity (mr). Syndiotacticity (rr) is the proportion of two diads in a triad, which is a chain of three consecutive structural units, that are both racemo (rr). Similarly, atacticity (mr) is the proportion of two diads in a triad that are meso and racemo (mr). In addition, in the chain of structural units in a polymer molecule, those with the same stereoconfiguration are called meso, and those with the opposite stereoconfiguration are called racemo, and are respectively represented by m and r.

[0064] The syndiotacticity (rr) and atacticity (mr) ratios of the triads were determined in deuterated chloroform at 30°C. 1 It can be obtained by measuring the H-NMR spectrum. When TMS is set to 0 ppm in the spectrum, the chemical shift corresponding to syndiotacticity (rr) is observed in the range of 0.6 to 0.95 ppm, and the chemical shift corresponding to atacticity (mr) is observed in the range of 0.95 to 1.10 ppm. The ratio of these peak areas to the area in the region of 0.6 to 1.35 ppm is the syndiotacticity (rr) ratio and the atacticity (mr) ratio.

[0065] (Other ingredients) When a thermoplastic resin is used as the material for constituting the resin substrate of this embodiment, it may contain other known resins in combination as long as they can exhibit the properties required for the resin substrate of this embodiment and the resin optical element.

[0066] Other resins include, but are not limited to, rubber polymers such as acrylic rubber, polyethylene resins, polypropylene resins, polystyrene resins, syndiotactic polystyrene resins, polycarbonate resins, ABS resins, acrylic resins, AS resins, BAAS resins, MBS resins, AAS resins, biodegradable resins, polyurethane resins, polycarbonate-ABS resin alloys, polyalkylene arylate resins (polybutylene terephthalate, polyethylene terephthalate, polypropylene terephthalate, polytrimethylene terephthalate, polyethylene naphthalate, etc.), polyamide resins, polyphenylene ether resins, polyphenylene sulfide resins, phenolic resins, and the like. The above-mentioned various thermoplastic resins may be used singly or in combination of two or more resins.

[0067] In particular, when used in combination with methacrylic resins, AS resins and BAAS resins are preferred from the viewpoint of improving fluidity, acrylic rubber polymers, ABS resins, and MBS resins are preferred from the viewpoint of improving impact resistance, and polyester resins are preferred from the viewpoint of improving chemical resistance. Polycarbonate resins are preferred when it is necessary to impart heat resistance, impact resistance, or adjust optical properties. Furthermore, acrylic resins have good compatibility with the aforementioned methacrylic resins, and are preferred when it is necessary to adjust properties such as fluidity and impact resistance while maintaining transparency.

[0068] In the thermoplastic resin used in this embodiment, when the above-described thermoplastic resin and the other resin are combined, it is sufficient that the effects of the present invention can be exhibited. However, in consideration of the effect of imparting properties, the blending ratio of the other resin is preferably 50% by mass or less, more preferably 40% by mass or less, based on 100% by mass of the total amount of the above-described thermoplastic resin and the other resin. It is preferably 5% by mass or less, more preferably 40% by mass or less, even more preferably 30% by mass or less, and particularly preferably 20% by mass or less. Furthermore, in consideration of the effect of imparting properties when other resins are blended, the lower limit of the amount of other resins blended is preferably 0.1% by mass or more, more preferably 1% by mass or more, even more preferably 2% by mass or more, still more preferably 3% by mass or more, and particularly preferably 5% by mass or more. The type and content of the other resin can be appropriately selected depending on the effect expected when used in combination with the other resin.

[0069] (additives) When a thermoplastic resin is used in this embodiment, an additive may be optionally blended in. The additive is not particularly limited as long as it can exhibit the effects of the present invention, and may be appropriately selected depending on the purpose.

[0070] Examples of additives include, but are not limited to, various stabilizers such as ultraviolet absorbers, heat stabilizers, and light stabilizers, release agents, lubricants, plasticizers, flame retardants, flame retardant aids, curing agents, curing accelerators, antistatic agents, conductivity imparting agents, stress relaxation agents, crystallization accelerators, hydrolysis inhibitors, chain extenders, compatibilizers, nucleating agents, reinforcing materials such as fillers, impact imparting agents, flow adjusters, dyes, sensitizers, colorants, thickeners, anti-settling agents, anti-sagging agents, fillers, antifoaming agents, coupling agents, light diffusing fine particles, refractive index adjusters, heat ray absorbers, rust inhibitors, antibacterial and anti-fungal agents, antifouling agents, and conductive polymers.

[0071] The resin substrate may be a thermosetting resin or an active energy curable resin.

[0072] When the thermosetting resin and / or active energy curable resin is used, examples thereof include (meth)acrylate-based resins, epoxy-based resins, silicone-based resins, aliphatic allyl carbonate-based resins, aromatic allyl carbonate-based resins, polyurethane-based resins, polythiourethane-based resins, episulfide-based resins, polyurea-based resins, etc. Furthermore, if necessary, antioxidants, ultraviolet absorbers, specific wavelength absorbers, release agents, curing agents, molecular weight modifiers, photochromic agents, etc. may be added within a range that does not impair the effects of the present invention.

[0073] <Moisture-proof layer> The moisture-proof layer of this embodiment is an amorphous film containing aluminum, silicon, oxygen, and carbon. If the moisture-proof layer has a polycrystalline structure, as in the technology disclosed in Patent Document 1, gas permeates through continuous pathways formed by the grain boundaries of the polycrystalline structure, turbulence near the grain boundaries, and voids in the columnar structure, making it impossible to achieve a high moisture-proof effect that can withstand long-term storage in a high-temperature, high-humidity environment. By using an amorphous moisture-proof layer, there is no continuous pathway for gas to permeate, so the gas permeation rate through the moisture-proof layer is suppressed, resulting in a high moisture-proof effect that can withstand long-term storage in a high-temperature, high-humidity environment, and imparting high shape stability and optical performance stability.

[0074] The moisture-proof layer of this embodiment may have voids inside. The presence of voids inside the moisture-proof layer reduces the moisture-proof effect of the moisture-proof layer, but improves its flexibility and shape stability and optical property stability under high-temperature, high-humidity environments. Therefore, the effects of this embodiment can be achieved by appropriately balancing the dispersion state of the voids with the thickness of the moisture-proof layer. The number, size, and dispersion state of the voids are determined by the amount of unreacted components of the raw material gas in the moisture-proof film and the amount of gas generated from the resin substrate, etc. Therefore, voids can be controlled by appropriately setting and implementing the film-forming conditions for the moisture-proof film, including the vacuum level of the chamber, and pretreatment (gas removal) of the resin substrate, etc. When voids are present inside the moisture-proof layer, it is preferable that the number of voids is appropriate so as not to significantly impair the moisture-proof effect and optical properties of the moisture-proof layer. Furthermore, it is preferable that the size of the voids is smaller than the thickness of each layer constituting the moisture-proof layer and that they have a discontinuous structure. If the voids are large enough or connected enough to penetrate the moisture-proof layer, the flow will be promoted by capillary action, and the moisture-proof effect will be significantly impaired. Furthermore, in order to suppress light scattering in the voids, it is preferable that the size of the voids is sufficiently smaller than the wavelength used in the optical molded product.

[0075] The moisture-proof layer preferably further contains nitrogen. The moisture-proof layer preferably has an alternate laminate structure of an aluminum-based composition layer containing aluminum, oxygen, and carbon, with the total content of aluminum, oxygen, and carbon being 70 atomic % or more, and a silicon-based composition layer containing silicon, oxygen, and nitrogen, with the total content of silicon, oxygen, and nitrogen being 70 atomic % or more. The total content of aluminum, oxygen, and carbon in the aluminum-based composition layer is preferably 70 atomic % or more, more preferably 75 atomic % or more, even more preferably 80 atomic % or more, and particularly preferably 85 atomic % or more. The total content is preferably 99.5 atomic % or less, more preferably 99 atomic % or less, and even more preferably 98.5 atomic % or less. Having the aluminum-based composition layer have a composition equal to or greater than the above-mentioned lower limit has the effect of providing excellent shape stability and optical performance stability in high-temperature, high-humidity environments. Furthermore, when the composition of the aluminum-based composition layer is equal to or less than the above upper limit, the flexibility of the moisture-proof layer is improved, and cracking in the moisture-proof layer and the optical functional layer is effectively suppressed in a high-temperature, high-humidity environment. The total content of silicon, oxygen, and nitrogen in the silicon-based composition layer is preferably 70 atomic % or more, more preferably 75 atomic % or more, and even more preferably 80 atomic % or more. Furthermore, it is preferably 99.5 atomic % or less, more preferably 99 atomic % or less, even more preferably 98 atomic % or less, even more preferably 97 atomic % or less, and particularly preferably 96 atomic % or less. When the composition of the silicon-based composition layer is equal to or less than the above lower limit, the shape stability and optical performance stability in a high-temperature, high-humidity environment are excellent. When the composition of the silicon-based composition layer is equal to or less than the above upper limit, the flexibility of the moisture-proof layer is improved, and cracking in the moisture-proof layer and the optical functional layer is effectively suppressed in a high-temperature, high-humidity environment.

[0076] In the moisture-proof layer, it is preferable that the element with the largest abundance ratio in the aluminum-based composition layer is oxygen and the element with the second largest abundance ratio is aluminum, and it is also preferable that the element with the largest abundance ratio in the silicon-based composition layer is oxygen and the element with the second largest abundance ratio is silicon. When the moisture-proof layer has the above composition, each layer of the moisture-proof layer has sufficient moisture-proof performance, and the moisture-proof layer as a whole exhibits high moisture-proof performance, thereby achieving high shape stability and optical performance stability.

[0077] In the moisture-proof layer, the ratio of the total thickness of the aluminum-based composition layer to the silicon-based composition layer (aluminum-based composition layer:silicon-based composition layer) is preferably 1:4 to 4:1, more preferably 1:3 to 3:1, and even more preferably 1:2 to 2:1. Generally, thin films made of inorganic compounds have film stress. The aluminum-based composition layer has tensile stress, and the silicon-based composition layer has compressive stress. A ratio of the total thickness of the aluminum-based composition layer to the silicon-based composition layer within the above range is preferable because the film stresses are appropriately offset, resulting in a low film stress for the entire moisture-proof layer. A low film stress for the entire moisture-proof layer is preferable from the viewpoints of suppressing deformation of the substrate due to the formation of the moisture-proof layer and improving adhesion between the moisture-proof layer and the substrate layer.

[0078] The alternating laminate structure preferably has a total of six or more layers. If the moisture-proof layer has a single-layer structure, cracks will form when the moisture-proof layer is unable to keep up with the expansion of the resin substrate in a high-temperature, high-humidity environment. In this case, gas will permeate through the continuous path formed by the penetrating cracks. Furthermore, capillary flow within the cracks will promote flow, significantly reducing the moisture-proof effect of the moisture-proof layer. On the other hand, if the moisture-proof layer has a laminate structure, even if cracks occur in some layers of the laminate structure, the cracks will stop at the interface of the laminate structure and will not penetrate the entire moisture-proof layer. Therefore, continuous paths of cracks will not form, and the moisture-proof layer as a whole can maintain a high moisture-proof effect. Furthermore, in this embodiment, a hard, low-flexibility optical functional layer is formed on the moisture-proof layer. The alternating laminate structure of the moisture-proof layer also has the effect of efficiently dispersing stresses that occur between the substrate, which has a high expansion coefficient, and the optical functional layer, which has a hard, low expansion coefficient, in a high-temperature, high-humidity environment. The greater the number of layers, the greater the effect of suppressing the occurrence of through cracks and dispersing stress, and the total number of layers is preferably 8 or more, even more preferably 10 or more, particularly preferably 12 or more, and especially preferably 14 or more. From the viewpoints of productivity and uniformity of the membrane structure, the number of layers is preferably 100 or less, more preferably 80 or less, even more preferably 60 or less, and particularly preferably 50 or less.

[0079] The moisture-proof layer preferably covers the entire surface of the molded product. Furthermore, the thickness distribution of the moisture-proof layer is preferably within 10%. If the moisture-proof layer has defects, non-formed areas, or areas with locally low moisture-proofing effect due to thickness variations, moisture absorption may progress unevenly from those areas, which may actually reduce the shape accuracy of the entire optical element.

[0080] When the moisture-proof layer is located on the outermost surface of the optical molded article, the outermost surface is preferably a silicon-based composition layer. The silicon-based composition layer has a relatively high surface hardness and low reactivity with components in the air and moisture, making it possible to maintain a stable film for a long period of time. In order to protect the moisture-proof layer and the resin substrate, the silicon-based composition layer on the outermost surface is preferably thicker than the silicon-based composition layer inside the moisture-proof layer.

[0081] The moisture-proof layer can be formed by a known method. From the viewpoint of obtaining an amorphous material with a uniform composition and uniformly covering the entire surface of the molded article, it is preferably formed by chemical vapor deposition, and more preferably by atomic layer deposition (ALD).

[0082] A known device can be used to perform ALD.

[0083] The source gas (precursor) used in ALD can be a known compound.

[0084] Examples of the source gas include organometallic sources, and more specifically, source gases containing organosilicon having an Si-O bond or an Si-C bond, a metal element-oxygen bond or a metal element-carbon bond, organometallic complexes, silicon or metal hydrides, etc. More specifically, examples of the reactive gas include silane (a general term for silicon hydrides), TEOS (TetraEthyl Orthosilicate), TMS (TriMethoxySilane), TES (TriEthoxySilane), TMA (TriMethyl Examples of suitable metal complexes include those containing not only one metal element but also heterodinuclear complexes containing multiple metal elements.

[0085] Examples of oxidizing gases used in ALD include oxygen, water (water vapor), ozone, ammonia, and nitrogen. The source gas and oxidizing gas may be supplied into the reaction chamber of the ALD film formation apparatus using a carrier gas (N, Ar, He, etc.).

[0086] The moisture-proof layer can be formed by thermal ALD, which uses heat to promote a chemical reaction, or PE-ALD (Plasma-Enhanced ALD), which uses plasma to promote a chemical reaction. From the viewpoints of minimizing damage to the substrate during film formation, obtaining a moisture-proof layer with good adhesion, easily adjusting the composition within a suitable range, further minimizing deterioration of moisture-proof performance in high-temperature, high-humidity environments, and obtaining optical elements with higher shape stability and performance stability, it is preferable for the layer to be formed by thermal ALD, in which an organic metal precursor is reacted as a raw material gas and ozone gas is reacted as a reactive gas.

[0087] The composition, structure, and film thickness uniformity obtained by ALD vary depending on various parameters such as the type of source gas and oxidizing gas, gas flow rate, pulse time, film formation temperature, and pressure. For example, they can be controlled by the following parameters. By appropriately setting these parameters, a moisture-proof film with the desired composition, structure, and film thickness uniformity in this embodiment can be obtained. Film formation temperature: The aluminum, silicon, oxygen, carbon, and nitrogen content varies depending on the film formation temperature. However, the content may increase or decrease depending on the adsorption state and reactivity of the source gas during the source gas supply stage. Focusing on the adsorption state of the source gas, for example, if the source gas is physically adsorbed to the film formation surface and undergoing an agglomeration reaction, increasing the film formation temperature increases the kinetic energy of the source gas, reducing the effects of physical adsorption and reducing the likelihood of unreacted components remaining, resulting in an increase in the aluminum, silicon, and oxygen content. On the other hand, if the source gas is not completely adsorbed to the film surface, increasing the film formation temperature facilitates the adsorption reaction. However, depending on the structure of the source gas, the above-mentioned agglomeration reaction may occur, resulting in a decrease in the aluminum, silicon, and oxygen content. Increasing the film formation temperature too much may promote desorption of the adsorbed gas, resulting in poor film thickness uniformity. Focusing on the reactivity of the source gas, generally, higher temperatures increase reactivity, resulting in an increase in the aluminum and silicon content. From a structural standpoint, at high temperatures, the molecules formed in the film easily move to their restabilized positions (on the crystal lattice), so at low film formation temperatures, an amorphous film is more likely to form, while at high temperatures, a crystalline film is more likely to form. Selection of raw material gas: The more reactive the raw material gas, the less likely it is that unreacted components will remain, and therefore the content of aluminum, silicon, and oxygen will increase. Raw material gas exhaust time: The shorter the raw material gas exhaust time, the greater the influence of remaining unreacted components due to the physical adsorption of the raw material gas, and the lower the aluminum, silicon, and oxygen contents. Selection of oxidizing gas: Using a highly reactive oxidizing gas will accelerate the reaction and increase the content of aluminum, silicon, and oxygen. Oxidizing gas concentration: Increasing the concentration of oxidizing gas accelerates the reaction, increasing the content of aluminum, silicon, and oxygen. It also improves film thickness uniformity. Pulse time of oxidizing gas: The longer the oxidizing gas is flowed, the more the reaction progresses, increasing the content of aluminum, silicon, and oxygen. It also improves the film thickness uniformity. Oxidizing gas lifespan: When a gas with a short lifespan (activated species) is used as the oxidizing gas, the oxidizing gas becomes inactivated before it reaches the entire surface of the molded product, which makes it easier for unreacted raw material gas to remain, resulting in lower aluminum, silicon, and oxygen content. Also, film thickness uniformity decreases. Degree of vacuum during evacuation: If the degree of vacuum during evacuation is low (pressure is high), the raw material gas and oxidizing gas will not be sufficiently discharged, which will increase the impact of remaining unreacted components and reduce the content of aluminum, silicon, and oxygen. In addition, the lower the content of aluminum, silicon, and oxygen in the obtained film, the more likely it is that an amorphous film will be produced.

[0088] The ALD film formation temperature is preferably high enough to prevent deterioration or deformation of the substrate. Here, the film formation temperature refers to the temperature of the chamber inner wall into which the substrate is placed during film formation. Because the substrate is primarily heated by radiant heat from the chamber inner wall, the substrate temperature is typically about 20°C lower than the chamber inner wall. The film formation temperature is preferably set so that the substrate temperature is at least 30°C lower than the reliability test temperature, and more preferably higher than the reliability test temperature. Specifically, the film formation temperature is preferably 60°C or higher, more preferably 70°C or higher, even more preferably 80°C or higher, and particularly preferably 90°C or higher. When determining the difference in expansion coefficients between the substrate and the moisture-proof layer, the reference temperature at which the strain between them becomes zero is near the substrate temperature during film formation. Therefore, film formation at a film formation temperature near the reliability test temperature or higher reduces the difference in expansion coefficients between the substrate and the moisture-proof layer during the reliability test and enhances the effectiveness of the moisture-proof layer as a buffer layer. This can suppress the occurrence of cracks due to differences in the expansion coefficients of the substrate, moisture-proof layer, and optical functional layer. On the other hand, from the viewpoint of suppressing the occurrence of cracks at low temperatures of −30° C. or lower due to decomposition of the source gas, deformation of the substrate due to film stress, and differences in the shrinkage coefficients of the substrate, moisture-proof layer, and optical functional layer, and from the viewpoint of suppressing the formation of a crystalline phase and obtaining an amorphous film with excellent moisture-proof performance and flexibility, the film formation temperature is preferably 150° C. or lower, more preferably 140° C. or lower, even more preferably 130° C. or lower, and particularly preferably 120° C. or lower.

[0089] The thickness of each layer of the moisture-proof layer is not particularly limited, but is preferably 1 nm or more, more preferably 2 nm or more, and even more preferably 5 nm or more. It is also preferably 50 nm or less, more preferably 30 nm or less, even more preferably 20 nm or less, even more preferably 15 nm or less, and especially preferably 10 nm or less. Having the thickness of each layer within the above range is preferable from the viewpoints of suppressing film peeling and cracking caused by film stress, transparency, flexibility, and productivity. The thickness of each layer may be the same or different.

[0090] In order to suppress chemical changes in the moisture-proof layer caused by long-term exposure to a constant temperature and humidity environment and maintain good moisture-proof performance for a long period of time, it is preferable that the outermost layer of the moisture-proof layer (the layer farthest from the resin substrate) be a silicon-based composition layer. This silicon-based composition layer may have the same thickness as or a different thickness from the silicon-based composition layer located further inward (closer to the resin substrate), but it is preferable that it be thicker than the inner silicon-based composition layer. If the thicknesses are different, from the viewpoint of improving the protective properties of the moisture-proof film, the thickness is preferably 5 nm or more, more preferably 10 nm or more, even more preferably 15 nm or more, and most preferably 20 nm or more. On the other hand, from the viewpoints of crack suppression and productivity, the thickness is preferably 100 nm or less, more preferably 50 nm or less, and even more preferably 30 nm or less.

[0091] From the viewpoint of the moisture-proof performance of the layer itself, the total thickness of the moisture-proof layer is preferably 20 nm or more, more preferably 30 nm or more, even more preferably 50 nm or more, and even more preferably 60 nm or more, and from the viewpoints of productivity, maintaining good flexibility of the entire moisture-proof layer, and suppressing cracking, the total thickness is preferably 200 nm or less, more preferably 150 nm or less, even more preferably 120 nm or less, and even more preferably 100 nm or less.

[0092] <Aluminum-based composition layer> From the viewpoint of the flexibility and crack resistance of the layer, the carbon content in the aluminum-based composition layer is preferably 0.1 atomic % or more, more preferably 1 atomic % or more, even more preferably 2 atomic % or more, and particularly preferably 3 atomic % or more. From the viewpoint of the moisture resistance of the layer, it is preferably 10 atomic % or less, more preferably 9 atomic % or less, and even more preferably 8 atomic % or less. A carbon content in this range is preferable from the viewpoint of a balance between the moisture resistance, flexibility, and crack resistance of the layer. A carbon content in this range is also preferable from the viewpoint of facilitating the formation of an amorphous film when the film is formed at a film formation temperature below the heat resistance temperature of the resin substrate (approximately 150°C or less).

[0093] The aluminum-based composition layer may further contain other atoms in addition to aluminum, oxygen, and carbon. For example, it may contain nitrogen, silicon, etc. When other atoms are contained, the content of each atom is preferably less than the content of aluminum atoms in the aluminum-based composition layer.

[0094] <Silicon-based composition layer> The nitrogen content of the silicon-based composition layer is preferably 0.1 atomic % or more, more preferably 0.2 atomic % or more, and even more preferably 0.4 atomic % or more, from the viewpoint of the flexibility and crack resistance of the layer. Furthermore, from the viewpoint of the moisture resistance of the layer, it is preferably 10 atomic % or less, more preferably 8 atomic % or less, even more preferably 6 atomic % or less, and particularly preferably 4 atomic % or less. A nitrogen content within this range is preferable from the viewpoint of a balance between the moisture resistance, flexibility, and crack resistance of the layer. Furthermore, a nitrogen content within this range is preferable from the viewpoint of facilitating the formation of an amorphous film when the film is formed at a film formation temperature below the heat resistance temperature of the resin substrate (approximately 150°C or less).

[0095] The silicon-based composition layer may further contain other atoms in addition to silicon, oxygen, and nitrogen. For example, it may contain carbon, aluminum, etc. When other atoms are contained, the content of each atom is preferably less than the content of silicon atoms in the silicon-based composition layer.

[0096] <Optical functional layer> The optical functional layer of this embodiment is an anti-reflection film and / or a partial reflection film.

[0097] An antireflection film is an optical functional layer that has the function of reducing the surface reflectance of incident light. Typically, it is a layer with a spectral reflectance of less than 1% in the visible light wavelength range (400 to 700 nm), but the applicable wavelength range and spectral reflectance value can be appropriately set depending on the application of the optical molded article.

[0098] A partially reflective film is an optical functional layer that reflects part of incident light and transmits part of it. A typical example is a half mirror with a spectral reflectance of 50%±5% in the visible light wavelength range (400 to 700 nm), but the applicable wavelength range and spectral reflectance value can be appropriately set depending on the application of the optical molded article.

[0099] The optical functional layer of this embodiment may be formed by a known method, such as vacuum deposition, sputtering, ion plating, dipping, or inkjet printing.

[0100] The optical functional layer of this embodiment can have a layer structure such as a dielectric single layer film, a dielectric multilayer film, a metal film, a thermosetting resin, an active energy ray curable resin, etc. Also, a moth-eye structure in which the refractive index changes continuously due to the air layer from the side closer to the moisture-proof layer can be used.

[0101] The optical functional layer may cover the entire surface of the optical molded product, or may cover only a portion through which light passes. In addition, when there are multiple optically effective surfaces, the optical functional layer may be formed on any one surface or on multiple surfaces.

[0102] In addition, as long as the optical functional layer has an anti-reflection film and / or a partially reflective film, it may also have other optical functional layers at the same time, such as high reflectivity (mirror), band-pass filter, edge filter, dichroic filter, notch filter, etc.

[0103] <Articles using optical molded articles> The optical molded article of the present embodiment may be used in combination with a housing as needed, or may be used as the housing itself. Also, it may be used by laminating a film such as a protective film or an optical film.

[0104] The optical molded article of this embodiment can be suitably used as an optical element in applications such as optical components in household products, office automation equipment, audiovisual equipment, battery electrical components, lighting equipment, and automobile components.

[0105] One suitable example is a lens for a head-mounted display (HMD) for virtual reality (VR). Because a head-mounted display is an image display device worn on the head, it is required to be small, lightweight, and comfortable to wear. As a means for miniaturizing the display, a method has been proposed in which a lens is combined with a quarter-wave plate and a reflective polarizing plate, etc., to change the polarization state of light after passing through the lens and switch between reflection and transmission, thereby causing the image to make one and a half round trips through a single lens (U.S. Patent No. 6,563,638, JP 2017-21321 A, etc.).

[0106] The above method has the following mechanism, for example. A quarter-wave plate and a reflective polarizer are placed on the back of a lens with a partially reflective coating on the front surface. Circularly polarized light entering the front of the lens is converted to linearly polarized light by the quarter-wave plate after passing through the lens. This linearly polarized light is reflected by the reflective polarizer and converted again by the quarter-wave plate into the opposite circularly polarized light, which enters the lens from the back and reaches the partially reflective coating on the front surface. The light reflected by the partially reflective coating and exiting the back of the lens is converted by the quarter-wave plate into linearly polarized light with a 90° difference in direction from the original, passes through the reflective polarizer, and enters the eye as an image. In this way, a high magnification and wide field of view can be obtained even in a thin optical module.

[0107] If the polarization state changes while passing through a lens, for example, some of the light will be transmitted through the reflective polarizing plate after passing through the lens for the first time, causing low-magnification images and high-magnification images to overlap, making it difficult to obtain a clear image, so lenses with low birefringence are needed.In addition, changes in humidity during use can change the shape of the lens, which can have an undesirable effect on imaging performance, so lenses with low moisture absorption and high shape stability in high-temperature, high-humidity environments are needed.

[0108] Other examples of suitable uses of optical elements made from the molded article of this embodiment include optical components in household goods, office automation equipment, audiovisual equipment, battery-powered electrical components, lighting equipment, and the like, such as light guide plates, display front panels, and touch panels used in displays of smartphones, PDAs, tablet PCs, LCD televisions, and the like; lenses and prisms used in smartphone and tablet PC camera lenses and bending optical system telephoto cameras (periscope cameras); optical components used in VR (virtual reality) / AR (augmented reality) / MR (mixed reality) / XR (cross reality) head-mounted displays, LCD projectors, near-infrared sensors (LiDAR; Light Detection Ranging), and the like, such as prism elements, waveguides, freeform light guide members, and lenses, particularly optical lenses with small, thin, and irregular thickness shapes; optical fibers, optical fiber coating materials, lenses and prisms for optical communications, lenses, Fresnel lenses, phase plates with microlens arrays, optical cover parts, substrates constituting polarization separation elements, polarizer / retardation films and substrates to which they are attached, and lenses.

[0109] Optical components in automobiles and the like include light guide plates for in-vehicle displays; optical covers made of front panels or curved molded bodies used in in-vehicle meter panels, instrument clusters, car navigation systems, information displays, rear seat-mounted displays, etc.; lenses and prisms used in head-up displays, light direction conversion elements, waveguides, light guides, combiners, dustproof sheets, optical cover parts, etc.; in-vehicle camera lenses (especially front lenses); light guide rods, etc.

[0110] Optical components used in aerial displays include, for example, the substrates of retroreflective sheets and partially transmissive mirrors, optical elements with submillimeter shapes for constructing two-sided corner reflector arrays, microlens arrays, substrates of concave-convex mirrors, lenses for enlarging and reducing images and correcting image planes and aberrations, light-guiding members, and direction-changing elements.

[0111] In addition to the above, the present invention can also be preferably used as a camera focusing screen, or as a component for a digital signage display device that displays information on a thin display connected to a network for the purpose of publicity, advertising, etc., in places such as outdoors, in stores, public institutions, and transportation facilities. [Example]

[0112] The present invention will be specifically described below with reference to examples and comparative examples, but the present invention is not limited to the following examples.

[0113] The raw materials used in the production examples are as follows:

[0114] [Monomer] Methyl methacrylate (MMA): manufactured by Asahi Kasei Corporation N-phenylmaleimide (phMI): Nippon Shokubai Co., Ltd. N-Cyclohexylmaleimide (chMI): Nippon Shokubai Co., Ltd.

[0115] [Organic solvents] Meta-xylene (mXy): Mitsubishi Gas Chemical Company, Ltd.

[0116] [Polymerization initiator] 1,1-Di(t-butylperoxy)cyclohexane: NOF Corporation, Perhexa C

[0117] [Chain transfer agent] n-Octyl mercaptan: Chevron Phillips Chemical Company

[0118] (Production Example 1: Methacrylic Resin A) 358.6 kg of methyl methacrylate (hereinafter referred to as MMA), 29.4 kg of N-phenylmaleimide (hereinafter referred to as phMI), 67.7 kg of N-cyclohexylmaleimide (hereinafter referred to as chMI), 0.77 kg of n-octyl mercaptan as a chain transfer agent, and 224.3 kg of meta-xylene (hereinafter referred to as mXy) ​​were weighed and placed in a 1.25 m 3 The mixture was added to the reactor and stirred to obtain a mixed monomer solution. Next, 88.0 kg of MMA, 6.3 kg of phMI, and 142.4 kg of mXy were weighed and added to Tank 1 with stirring to obtain a mixed monomer solution for addition. The liquid in the reactor was bubbled with nitrogen at a rate of 30 L / min for 1 hour, and the liquid in Tank 1 was bubbled with nitrogen at a rate of 10 L / min for 30 minutes to remove dissolved oxygen. Thereafter, steam was blown into the jacket to raise the solution temperature in the reactor to 115°C, and polymerization was initiated by adding a polymerization initiator solution prepared by dissolving 0.470 kg of 1,1-di(t-butylperoxy)cyclohexane in 1.905 kg of mXy at a rate of 1.0 kg / hour while stirring at 50 rpm. During the polymerization, the solution temperature in the reactor was controlled at 115±2° C. by temperature regulation using a jacket. 30 minutes after the start of the polymerization, the addition rate of the initiator solution was reduced to 0.5 kg / hour. In addition, starting from 1 hour after the start of polymerization, the additional mixed monomer solution was added in its entirety from Tank 1 at a constant rate over a period of 4 hours. Furthermore, the addition rate of the initiator solution was reduced to 0.25 kg / hour 3.5 hours after the start of polymerization, and the addition was stopped 5 hours after the start of polymerization. After 12 hours had passed since the start of the polymerization, a polymer solution containing a methacrylic resin having a ring structure in the main chain was obtained, and the polymerization was terminated. This polymer solution was fed to a concentration device consisting of a tubular heat exchanger preheated to 250°C and a vaporization tank, and devolatilization was carried out. The vacuum in the vaporization tank was set to 10 to 15 Torr. The resin flowing down the vaporization tank was discharged with a gear pump, extruded through a strand die, water-cooled, and pelletized to obtain methacrylic resin A. The composition of the resulting pellet-shaped polymer was confirmed to be 81.0 mass %, 6.6 mass %, and 12.4 mass % of structural units derived from MMA, phMI, and chMI monomers, respectively, and the weight-average molecular weight was 108,000, Mw / Mn was 2.04, and the glass transition temperature was 134°C.

[0119] (Production Example 2: Methacrylic Resin B) Glutarimidated resin was produced using a 15 mm diameter, co-rotating, intermeshing twin-screw extruder. The raw resin was a methyl methacrylate-styrene copolymer (8% styrene by mass) with a molecular weight of 100,000 and monomethylamine as the imidizing agent. The temperature settings for each temperature control zone were 230–250°C, and the screw speed was 150 rpm. Methyl methacrylate-styrene copolymer (hereinafter also referred to as “MS resin”) was fed at a rate of 2 kg / hr. The resin was melted and filled using a kneading block, and then 8 parts by mass of monomethylamine was injected into the reaction zone through a nozzle. A reverse flight was installed at the end of the reaction zone to fill the zone with resin. Post-reaction by-products and excess monomethylamine were removed by reducing the pressure at the vent port to −0.092 MPa. The resin exited the die at the extruder outlet as strands, which were cooled in a water bath and pelletized using a pelletizer to obtain glutarimidated MS resin intermediate (1). Next, a 15 mm diameter co-rotating intermeshing twin-screw extruder was set at 230°C and 150 rpm for each temperature control zone. The glutarimidated MS resin intermediate (1) was fed from the hopper at a rate of 1 kg / hr. The resin was melted and filled using a kneading block. A mixture of 0.8 parts by mass of dimethyl carbonate and 0.2 parts by mass of triethylamine was then injected into the resin through a nozzle to reduce the carboxyl groups in the resin. A reverse flight was added to the end of the reaction zone to fill the resin. The post-reaction by-products and excess dimethyl carbonate were removed by reducing the pressure at the vent port to -0.092 MPa. The resin exiting the die at the extruder outlet as strands was cooled in a water bath and then pelletized using a pelletizer to obtain glutarimidated MS resin intermediate (2). The glutarimidated MS resin intermediate (2) was then fed into a 15 mm diameter, co-rotating, intermeshing twin-screw extruder with each temperature-controlled zone set at 230°C, a screw speed of 150 rpm, and a feed rate of 1 kg / hr. The pressure at the vent port was reduced to -0.095 MPa, and volatiles such as unreacted secondary materials were once again removed. The devolatilized imide resin emerged as strands from the die at the extruder outlet and was cooled in a water bath. It was then pelletized in a pelletizer to obtain methacrylic resin B (glutarimidated MS resin). The weight average molecular weight of methacrylic resin B was 85,000, Mw / Mn was 1.8, the content of monomer units in the copolymer was 8 mass% styrene units, 82 mass% MMA units, and 10 mass% glutarimide units, and the glass transition temperature was 128°C.

[0120] (Production Example 3: Methacrylic Resin C) A reaction vessel equipped with a stirrer, a temperature sensor, a cooling pipe, a nitrogen inlet pipe, and a dropping pump was charged with 5.40 parts by mass of methyl 2-(hydroxymethyl)acrylate (hereinafter referred to as RHMA), 37.6 parts by mass of methyl methacrylate (hereinafter referred to as MMA), 0.450 parts by mass of styrene (hereinafter referred to as St), and 90.0 parts by mass of toluene, and the temperature was raised to 105°C while nitrogen was passed through. As an initial initiator, a solution consisting of 3.63 parts by mass of toluene and 0.245 parts by mass of t-amyl peroxy isononanoate was added dropwise over 9 minutes, while solution polymerization was carried out at 105°C to 110°C. Then, 11 minutes later, a solution consisting of 4.42 parts by mass of toluene and 0.298 parts by mass of t-amyl peroxy isononanoate was added dropwise over 180 minutes as a dropping initiator. Simultaneously with the addition of the dropping initiator, a solution consisting of 6.6 parts by mass of RHMA, 45.9 parts by mass of MMA, and 4.05 parts by mass of St was added dropwise over 180 minutes, while solution polymerization was carried out at 105°C to 110°C, and the mixture was then aged for another 100 minutes. To the obtained polymerization solution, a solution consisting of 1.20 parts by mass of toluene and 0.0750 parts by mass of stearyl phosphate was added as a catalyst (cyclization catalyst) for the cyclization condensation reaction, and the cyclization condensation reaction to form a lactone ring structure was allowed to proceed for 1.5 hours under reflux at approximately 90°C to 110°C. The resulting polymerized solution was then passed through a multi-tube heat exchanger maintained at 220°C to complete the cyclocondensation reaction. The polymerized solution was then introduced into a vented twin-screw extruder (L / D = 52) equipped with a leaf-disk polymer filter (filtration accuracy: 5 μm) at its tip at a processing rate of 90 parts by mass / hour (based on resin amount) to devolatilize the polymerized solution. The vented twin-screw extruder used had one rear vent and four fore vents (referred to as the first, second, third, and fourth vents from the upstream side). The barrel temperature was 220°C, and the vacuum level was 13.3 to 400 hPa (10 to 300 mmHg). During devolatilization, ion-exchanged water was introduced from behind the first, second, and third vents at a rate of 1.3 parts by mass / hour. The weight-average molecular weight of the obtained methacrylic resin C was 102,000, Mw / Mn was 2.3, the glass transition temperature was 125°C, and the proportions of MMA units, styrene units, lactone ring structures, and RHMA units in the copolymer were 76.8 mass%, 4.6 mass%, 16.9 mass%, and 1.7 mass%, respectively.

[0121] (Production Example 4: Methacrylic Resin D) A monomer composition consisting of 63.08 parts by mass of MMA, 38.54 parts by mass of styrene, and 0.46 parts by mass of t-amylperoxy-2-ethylhexanoate as a polymerization initiator was continuously fed into a 10-L incomplete mixing vessel equipped with a helical ribbon impeller at a rate of 1 kg / h. Continuous polymerization was carried out at an average residence time of 2.5 hours and a polymerization temperature of 150°C. The liquid was continuously withdrawn from the bottom to maintain a constant liquid level in the vessel, and then fed into a concentrator consisting of a tubular heat exchanger and a vaporizer for devolatilization. The vaporizer was maintained at a vacuum of 10-15 Torr. The resin flowing down the vaporizer was discharged using a screw pump, extruded through a strand die, water-cooled, pelletized, and introduced into a solvent removal apparatus to obtain pelletized methyl methacrylate-styrene copolymer. This copolymer was dissolved in methyl isobutyrate to prepare a 10% by weight methyl isobutyrate solution. A 1000 mL autoclave was charged with 500 parts by weight of this 10% by weight methyl isobutyrate solution of the copolymer and 1 part by weight of 10% by weight Pd / C as a hydrogenation catalyst. The mixture was maintained at 200°C under a hydrogen pressure of 9 MPa for 15 hours to hydrogenate the aromatic double bonds in the styrene moieties of the copolymer. The hydrogenation catalyst was removed using a filter, and 0.04 parts by weight of Rikemal H-100 was added to the polymer solution and mixed. The mixture was then fed to a concentrator consisting of a tubular heat exchanger and a vaporizer for devolatilization. The vacuum in the vaporizer was set to 10-15 Torr. The resin flowing down the vaporizer was discharged using a gear pump, extruded through a strand die, cooled with water, and pelletized to obtain methacrylic resin D. The composition of the obtained pellets was confirmed by absorbance measurement at a wavelength of 260 nm, which showed that the hydrogenation rate of the aromatic double bonds in the styrene moieties was 99%. Furthermore, NMR measurement showed that the structural units derived from MMA and vinylcyclohexane monomers in the copolymer accounted for 60.7% and 39.3% by mass, respectively. The weight-average molecular weight was 167,000, the Mw / Mn was 1.9, and the glass transition temperature was 118°C.

[0122] (Production Example 5: Methacrylic Resin E) Methacrylic resin E was obtained in the same manner as in Production Example 4, except that 75.09 parts by mass of MMA and 26.04 parts by mass of styrene were used. The composition of the obtained pellets was confirmed by absorbance measurement at a wavelength of 260 nm, which showed that the hydrogenation rate of the aromatic double bonds in the styrene moieties was 99%. Furthermore, NMR measurement showed that the structural units derived from MMA and vinylcyclohexane monomers in the copolymer accounted for 73.2% and 26.8% by mass, respectively. The weight-average molecular weight was 148,000, Mw / Mn was 2.0, and the glass transition temperature was 118°C.

[0123] <Evaluation> The resins prepared in the production examples were evaluated as follows. (1) Analysis of structural units Unless otherwise specified in each manufacturing example, 1 H-NMR measurement and 13The structural units of the produced thermoplastic resin were identified by C-NMR measurement, and their abundance was calculated. 1 H-NMR measurement and 13 The measurement conditions for C-NMR measurement are as follows: Measuring equipment: JEOL Ltd. ECZ400 Measurement solvent: CDCl3 or DMSO-d6 ·Measurement temperature: 40℃

[0124] (2) Molecular weight measurement The weight average molecular weight (Mw) and number average molecular weight (Mn) of the thermoplastic resins produced in the Production Examples were measured using the following apparatus and conditions. Measurement equipment: Tosoh Corporation, gel permeation chromatography (HLC-8320GPC) Measurement conditions: Columns: One TSKguardcolumn SuperH-H, two TSKgel SuperHM-M, and one TSKgel SuperH2500 were connected in series. Column temperature: 40℃ The developing solvent was tetrahydrofuran, the flow rate was 0.6 mL / min, and 0.1 g / L of 2,6-di-t-butyl-4-methylphenol (BHT) was added as an internal standard. Detector: RI (differential refractive index) detector, detection sensitivity: 3.0 mV / min Sample: 0.02 g of thermoplastic resin in 20 mL of tetrahydrofuran. Injection volume: 10 μL. Standard sample for calibration curve: The following ten types of polymethyl methacrylate (PMMACalibration Kit MM-10, manufactured by Polymer Laboratories) with known monodisperse weight peak molecular weights and different molecular weights were used. Weight peak molecular weight (Mp) Standard sample 1 1,916,000 Standard sample 2 625,500 Standard sample 3 298,900 Standard sample 4 138,600 Standard sample 5 60,150 Standard sample 6 27,600 Standard sample 7 10,290 Standard sample 8 5,000 Standard sample 9 2,810 Standard sample 10,850 Under the above conditions, the RI detection intensity was measured against the elution time of the thermoplastic resin. Based on the calibration curve obtained by measuring the standard samples for the calibration curve, the weight average molecular weight (Mw) and number average molecular weight (Mn) of the thermoplastic resin were determined.

[0125] (3) Measurement of glass transition temperature The glass transition temperature (Tg) (°C) of the thermoplastic resin was measured in accordance with JIS-K7121. First, a sample was conditioned (left at 23°C for one week) under standard conditions (23°C, 50% RH), and four test pieces (four locations) of approximately 10 mg each were cut out. Next, using a differential scanning calorimeter (PerkinElmer Japan Co., Ltd. Diamond DSC) under conditions of a nitrogen gas flow rate of 25 mL / min, the sample was heated from room temperature (23 ° C) to 200 ° C (first heating) at 10 ° C / min, held at 200 ° C for 5 minutes to completely melt the sample, then cooled from 200 ° C to 40 ° C at 10 ° C / min, held at 40 ° C for 5 minutes, and heated again under the above heating conditions (second heating). The DSC curve drawn during this heating period was measured by measuring the intersection of the step-change curve during the second heating period with a line equidistant from each baseline extension in the vertical direction (midpoint glass transition temperature). Four measurements were performed per sample, and the arithmetic mean (rounded to the nearest whole number) of the four measurements was taken as the measured value.

[0126] [Example 1] (Lens molding) Using the methacrylic resin A obtained in Production Example 1, an injection molding machine (FANUC, S-2000i50B) was used to injection mold a biconvex lens with an optical axis thickness of 7.0 mm and an effective diameter of φ41 mm. The finished lens had an aspherical shape with a radius of curvature of R93.5 mm on one side including the optical axis, a conic constant k=-1.12452, and no even-order constants. The other side including the optical axis had a spherical shape with a radius of R67 mm. Molding was performed with a cylinder temperature set to Tg + 135°C of the methacrylic resin A used, and a mold temperature set to Tg - 15°C of the methacrylic resin A used. The holding pressure was set to 60 MPa for 4 seconds in the first stage, followed by 40 MPa for 3 seconds in the second stage to relieve stress distortion inside the molded product. Molding was also performed with an injection speed set to 10 mm / s, resulting in a lens molded product.

[0127] (Moisture-proof layer deposition) An atomic layer deposition (ALD) system (Meiden Nanoprocess Innovation, PO-ALD) was used to deposit an alternating layer film consisting of an aluminum-based composition layer and a silicon-based composition layer on the entire surface of the above-mentioned lens. First, a 10 nm thick aluminum-based composition layer was deposited by thermal ALD at a deposition temperature of 110 °C using DMAI gas as the organometallic source and high-concentration ozone gas generated by a pure ozone generator (Meidensha, MPOG-HM1A1) as the oxidant. Next, a 10 nm thick silicon-based composition layer was deposited by thermal ALD at a deposition temperature of 110 °C using Orthrus (registered trademark, Air Liquide) as the organometallic source and high-concentration ozone gas generated by a pure ozone generator (Meidensha, MPOG-HM1A1) as the reactant. The same deposition process was repeated four times under the same conditions, but the number of cycles was increased so that the silicon-based composition layer thickness for the fourth deposition was 30 nm. As a result, a lens was obtained whose entire surface was covered with a total of eight layers, each consisting of an aluminum-based composition layer and a silicon-based composition layer, each 100 nm thick. The total thickness of the aluminum-based composition layer was 40 nm, and the total thickness of the silicon-based composition layer was 60 nm.

[0128] (Deposition of optical functional layer) An anti-reflection coating consisting of an alternating laminated film of titanium oxide and silicon oxide was formed on the R67 mm spherical surface side of the lens by vacuum deposition to obtain the lens.

[0129] [Example 2] When forming the moisture-proof layer, thermal ALD was performed at a film formation temperature of 110°C, and the formation of 10 nm thick aluminum-based composition layers and 10 nm thick silicon-based composition layers was repeated four times alternately under the same conditions, resulting in a lens whose entire surface was covered with a total of eight 80 nm thick alternating laminated films having the compositions shown in Table 1. Here, the total thickness of the aluminum-based composition layers was 40 nm, and the total thickness of the silicon-based composition layers was 40 nm. A lens was obtained in the same manner as in Example 1 except for the above.

[0130] [Example 3] When forming the moisture-proof layer, thermal ALD was performed at a film formation temperature of 100°C, and the formation of 10 nm thick aluminum-based composition layers and 5 nm thick silicon-based composition layers was repeated four times alternately under the same conditions, resulting in a lens whose entire surface was covered with a total of eight layers, each 60 nm thick, of alternating laminated films having the compositions shown in Table 1. Here, the total thickness of the aluminum-based composition layers was 40 nm, and the total thickness of the silicon-based composition layers was 20 nm. A lens was obtained in the same manner as in Example 1 except for the above.

[0131] [Example 4] During deposition of the moisture-proof layer, thermal ALD was performed at a deposition temperature of 100°C, alternately repeating the deposition of 5 nm thick aluminum-based composition layers and 5 nm thick silicon-based composition layers eight times under the same conditions, but the number of cycles was increased so that the thickness of the eighth silicon-based composition layer was 25 nm. A total of 16 layers, each 100 nm thick, were deposited, each with the composition shown in Table 1. Here, the total thickness of the aluminum-based composition layers was 40 nm, and the total thickness of the silicon-based composition layers was 60 nm. Other than that, the same procedure as in Example 1 was carried out to obtain a lens.

[0132] [Example 5] When forming the moisture-proof layer, thermal ALD was performed at a film formation temperature of 120°C, and the formation of 10 nm thick aluminum-based composition layers and 5 nm thick silicon-based composition layers was repeated four times alternately under the same conditions, resulting in a lens whose entire surface was covered with a total of eight layers, each 60 nm thick, of alternating laminated films having the compositions shown in Table 1. Here, the total thickness of the aluminum-based composition layers was 40 nm, and the total thickness of the silicon-based composition layers was 20 nm. In addition, when producing the lens molded product, a partially reflective film (reflectivity 50%±5%, wavelength range 450 to 650 nm) consisting of an alternating laminate film of titanium oxide and silicon oxide was formed on the R67 mm spherical surface side of the lens by vacuum deposition. A lens was obtained in the same manner as in Example 1 except for the above.

[0133] [Example 6] When producing a lens molded product, the methacrylic resin B obtained in Production Example 2 was used, and the rest of the procedure was the same as in Example 1 to obtain a lens.

[0134] [Example 7] When producing a lens molded product, the methacrylic resin C obtained in Production Example 3 was used, and the rest of the procedure was the same as in Example 1 to obtain a lens.

[0135] [Example 8] When producing a lens molded product, the methacrylic resin D obtained in Production Example 4 was used, and the rest of the procedure was the same as in Example 1 to obtain a lens.

[0136] [Example 9] When producing a lens molded product, the methacrylic resin E obtained in Production Example 5 was used, and other procedures were carried out in the same manner as in Example 1 to obtain a lens.

[0137] [Comparative Example 1] A lens was obtained in the same manner as in Example 1, except that no moisture-proof layer was formed.

[0138] Comparative Example 2 A lens was obtained in the same manner as in Example 5, except that no moisture-proof layer was formed.

[0139] Comparative Example 3 In Example 1, when forming the moisture-proof layer, a 10 nm thick aluminum-based composition layer and a 10 nm thick silicon-based composition layer were alternately formed four times under the same conditions by vacuum deposition, but the film formation time was extended so that the thickness of the fourth silicon-based composition layer was 30 nm.The moisture-proof layer was formed on the aspherical side of the lens with a radius of 93.5 mm, and then on the spherical side with a radius of 67 mm.As a result, a lens was obtained in which both sides of the lens were covered with a total of eight layers, each 60 nm thick, and having the composition shown in Table 1. Other than that, the same procedure as in Example 1 was carried out to obtain a lens.

[0140] Comparative Example 4 In Example 3, when the moisture-proof layer was formed, a single aluminum-based composition layer having a thickness of 60 nm was formed. Other than that, the same procedure as in Example 3 was carried out to obtain a lens.

[0141] <Evaluation> The optical molded articles produced in the examples and comparative examples were evaluated as follows. The evaluation results are shown in Table 1.

[0142] (1) Composition of moisture-proof film The optical molded articles prepared in the Examples and Comparative Examples were subjected to XPS measurement from the air interface side of the moisture-proof layer under the following conditions to confirm the composition of the moisture-proof layer. The location where the aluminum or silicon concentration was maximum was used to determine the composition. <Analysis conditions> Equipment used: ULVAC-Phi VersaProbe II Excitation source: Monochromated Al Kα Analysis size: approx. 200 μmφ Photoelectron extraction angle: 45° Pass Energy: 46.95eV(Narrow) <Ar + Sputtering conditions> Acceleration: 1kV Raster size: 2mm x 2mm with Zalar rotation

[0143] (2) Thickness and structure of moisture-proof film The cross sections of the optical molded articles prepared in the Examples and Comparative Examples were observed under the following conditions to confirm the thickness uniformity of the moisture-proof layer. The crystallinity of each layer of the moisture-proof layer was also evaluated using electron diffraction patterns. When no diffraction rings were observed, it was determined that the layer had an amorphous structure, and it was confirmed whether each layer constituting the moisture-proof film had an amorphous structure. Equipment used (cross-section processing): Hitachi High-Tech NX5000, Japan FI Helios650 Equipment used (cross-section observation, electron diffraction): Hitachi High-Tech HD2300 The film thickness uniformity was evaluated according to the following criteria. A (Good): The difference between the film thickness at the maximum and minimum points is within 10% of the film thickness at the maximum point. However, if there are pinholes in the moisture-proof film, those points are excluded from the calculation. Also, if there are voids in the moisture-proof film, the voids are considered to be included in the film thickness. B (Poor): The value calculated by the above method exceeds 10%.

[0144] (3) Reliability test under high temperature and humidity conditions The optical molded bodies prepared in the examples and comparative examples were subjected to reliability tests under the following temperature and humidity conditions to evaluate their reliability in a high-temperature, high-humidity environment. The optical elements were placed in a thermo-hygrostat (PL-2J manufactured by Espec) set to the specified temperature and humidity conditions, and were taken out after being held there for 168 hours, 336 hours, and 504 hours, and then evaluated as follows (4) to (6). Temperature and humidity condition 1: 65°C, 90% RH Temperature and humidity condition 2: 85°C, 85% RH

[0145] (4) Shape stability evaluation The optical molded body was subjected to non-contact shape accuracy measurements under the following conditions before and after the reliability test in a high-temperature, high-humidity environment (i.e., 0 hours) and for a specified time, and shape stability was evaluated. The shape accuracy measurements were performed on the aspherical side where no optical functional layer was formed, because sufficient reflected light intensity was not obtained on the spherical side where an anti-reflection film was formed, making measurement using this measurement method difficult. Equipment used: Mitaka Koki NH-3SPs Measuring surface: Aspheric side Measurement location: perpendicular to the flow through the optical center of the optical element The evaluation was carried out according to the following criteria. A (Good): Absolute value of ΔPV is less than 2.0 μm B (fairly good): Absolute value of ΔPV is 2.0 μm or more and less than 5.0 μm C (slightly poor): Absolute value of ΔPV is 5.0 μm or more and less than 10.0 μm D (Poor): Absolute value of ΔPV is 10.0 μm or more Here, ΔPV is the amount of change in PV before and after the reliability test, and the Best Fit R value at 0 hours was used in common for the calculation.

[0146] (5) Appearance evaluation The appearance of the optical molded article was visually inspected before (i.e., 0 hour) and after the reliability test under a high-temperature, high-humidity environment for a predetermined time to check for the presence or absence of cracks. Evaluation was performed according to the following criteria. A (good): No cracks were observed. B (fairly good): A few cracks (1-2 lines) have occurred. C (slightly poor): Numerous cracks (several to several dozens) have occurred. D (Poor): Numerous cracks have occurred.

[0147] (6) Optical property evaluation Before the reliability test under high temperature and humidity environment (i.e., 0 hours) and after the specified time The optical molded article was subjected to measurement of the microspectroscopic reflectance of the optical functional layer. The change in the average reflectance in the wavelength range of 450 to 650 nm was confirmed before and after the reliability test. When the type of optical functional layer was an anti-reflection film, the evaluation was carried out according to the following criteria. A (Good): Change is less than 0.1% B (fairly good): Change is 0.1% or more but less than 0.2% C (slightly poor): Change is 0.2% or more and less than 0.5% D (bad): Change is 0.5% or more When the type of the optical functional layer was a partially reflective film, the evaluation was carried out according to the following criteria. A (Good): Change is less than 2.0% B (fairly good): Change is 2.0% or more and less than 2.5% C (slightly poor): Change is 2.5% or more and less than 3.0% D (Poor): Change is 3.0% or more

[0148] [Table 1] [Industrial Applicability]

[0149] The optical molded article of this embodiment has sufficient moisture-proofing properties, and has high shape stability and optical performance stability even in a high-temperature, high-humidity environment.

[0150] Suitable examples of the optical molded article of this embodiment include optical components in household appliances, office automation equipment, AV equipment, battery electrical components, lighting equipment, and the like, such as light guide plates, display front panels, and touch panels used in displays of smartphones, PDAs, tablet PCs, LCD televisions, and the like; lenses and prisms used in smartphone and tablet PC camera lenses and bending optical system telephoto cameras (periscope cameras); optical components used in VR (virtual reality) / AR (augmented reality) / MR (mixed reality) / XR (cross reality) head-mounted displays, liquid crystal projectors, near-infrared sensors (LiDAR; Light Detection Ranging), and the like, such as prism elements, waveguides, freeform light guide members, lenses, and particularly optical lenses with small, thin, uneven thickness shapes; optical fibers, optical fiber coating materials, lenses and prisms for optical communications, lenses, Fresnel lenses, phase plates with microlens arrays, optical cover parts, substrates constituting polarization separation elements, polarizers and retardation films, and substrates and lenses to which they are bonded.

[0151] Optical components used in automobiles and the like include light guide plates for in-vehicle displays; optical covers made of front panels or curved molded bodies used in in-vehicle meter panels, instrument clusters, car navigation systems, information displays, rear seat-mounted displays, etc.; lenses and prisms used in head-up displays, light direction conversion elements, waveguides, light guides, combiners, dustproof sheets, optical cover parts, etc.; in-vehicle camera lenses (especially front lenses); light guide rods, etc.

[0152] Optical components used in aerial displays include, for example, the substrates of retroreflective sheets and partially transmissive mirrors, optical elements shaped to submillimeter dimensions for constructing two-sided corner reflector arrays, microlens arrays, passive optical elements, substrates of concave-convex mirrors, lenses for enlarging and reducing images and correcting image planes and aberrations, light-guiding members, and direction-changing elements.

[0153] In addition to the above, the present invention can also be preferably used as a camera focusing screen, or as a component for a digital signage display device that displays information on a thin display connected to a network for the purpose of publicity, advertising, etc., in places such as outdoors, in stores, public institutions, and transportation facilities.

Claims

1. An optical molded article including a resin substrate, a moisture-proof layer, and an optical functional layer in this order, the moisture-proof layer is an amorphous film containing aluminum, silicon, oxygen, and carbon; The optical functional layer is an anti-reflection film and / or a partially reflective film. An optical molded article characterized by:

2. 2. The optical molded article according to claim 1, wherein the moisture-proof layer further contains nitrogen.

3. The moisture-proof layer is 2. The optical molded article according to claim 1, comprising an aluminum-based composition layer containing aluminum, oxygen, and carbon.

4. In the moisture proof layer, The aluminum-based composition layer includes a layer having a carbon content of 0.1 to 10 atomic %. The optical molded article according to claim 3 .

5. In the moisture proof layer, the total content of aluminum, oxygen, and carbon in the aluminum-based composition layer is 70 atomic % or more; The optical molded article according to claim 3 .

6. The moisture-proof layer is a silicon-based composition layer containing silicon, oxygen, and nitrogen; The optical molded article according to claim 2 or 3,

7. In the moisture proof layer, The silicon-based composition layer includes a layer having a nitrogen content of 0.1 to 10 atomic %. The optical molded article according to claim 6 .

8. In the moisture proof layer, the total content of silicon, oxygen, and nitrogen in the silicon-based composition layer is 70 atomic % or more; The optical molded article according to claim 6 .

9. The moisture-proof layer is The aluminum-based composition layer and the silicon-based composition layer are alternately laminated. The optical molded article according to claim 6 .

10. 10. The optical molded body according to claim 9, wherein in the moisture-proof layer, the ratio of the total thickness of the aluminum-based composition layers to the total thickness of the silicon-based composition layers (aluminum-based composition layers:silicon-based composition layers) is 1:4 to 4:

1.

11. 11. The optical molded product according to claim 10, wherein the total number of layers in the alternating laminate structure is 6 or more.

12. 12. The optical molded article according to claim 11, wherein the moisture-proof layer covers the entire surface of the molded article, and the film thickness distribution is within 10%.

13. 12. The optical molded article according to claim 11, wherein the resin substrate is formed from one or more resins selected from the group consisting of methacrylic resins, polyester resins, carbonate resins, norbornene resins, and modified norbornene resins.

Images