Method for manufacturing photochromic articles

Abstract

To provide a new photochromic article manufacturing method allowing manufacture of a photochromic article excellent in light fastness.SOLUTION: A manufacturing method of a photochromic article is provided. The photochromic article comprises a substrate, a photochromic layer comprising a photochromic compound, and a protective layer being a cured layer of a polymerizable composition, in this order. The manufacturing method comprises forming a coating layer of a polymerizable composition on the photochromic layer, and applying curing treatment to the coating layer, where the curing treatment is multistep light irradiation.SELECTED DRAWING: None

Description

[Technical Field]

[0001] This invention relates to a method for manufacturing photochromic articles. [Background technology]

[0002] Photochromic compounds are compounds that exhibit the property of developing color under irradiation with light in a photoresponsive wavelength range and fading under non-irradiation conditions (photochromicity). Hereinafter, articles containing photochromic compounds will be referred to as photochromic articles. For example, Patent Document 1 discloses a photochromic composition used in the manufacture of a photochromic article having a layer containing a photochromic compound (photochromic layer). [Prior art documents] [Patent Documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 3-121188 [Overview of the Initiative] [Problems that the invention aims to solve]

[0004] Photochromic articles are desirable to have excellent lightfastness (see, for example, Patent Document 1). This is because photochromic articles with excellent lightfastness experience less performance degradation due to long-term use.

[0005] On the other hand, the inventors considered adding a protective layer to photochromic articles in order to improve their performance. However, the results of the investigation revealed that photochromic articles with a protective layer may experience a decrease in light resistance.

[0006] In view of the foregoing, one aspect of the present invention is a method for manufacturing a photochromic article, with the aim of providing a new manufacturing method that enables the production of a photochromic article with excellent light resistance. [Means for solving the problem]

[0007] One aspect of the present invention is, A method for manufacturing a photochromic article, The above-mentioned photochromic article is a photochromic article having, in this order, a substrate, a photochromic layer containing a photochromic compound, and a protective layer which is a cured layer of a polymerizable composition. Forming a coating layer of polymerizable composition on the above photochromic layer, and The above coating layer is subjected to a curing treatment. including, and, The above curing treatment is a multi-stage light irradiation method for manufacturing photochromic articles (hereinafter also simply referred to as "manufacturing method"), Regarding.

[0008] During their research, the inventors found that photochromic articles, manufactured by forming a protective layer on a photochromic layer provided on a substrate, tended to experience a decrease in light resistance. Therefore, after further intensive research, the inventors discovered that by performing the curing treatment for forming the protective layer using multi-stage light irradiation, the decrease in light resistance could be significantly suppressed compared to cases where the protective layer was formed by curing treatment using a single stage of light irradiation. The inventors infer the following regarding this point. However, the present invention is not limited to the inferences described herein. The decrease in light resistance of a photochromic article having a photochromic layer on a substrate is thought to be caused by components contained in the substrate (hereinafter referred to as "substrate components") migrating to the photochromic layer and remaining there, degrading the photochromic compound. The inventors surmise that this migration of substrate components to the photochromic layer is accelerated when light irradiation is performed when forming a protective layer on the photochromic layer. In this regard, although the reason is not clear, it is thought that if such light irradiation is performed in multiple stages, the substrate components that have migrated to the photochromic layer will migrate more easily from the photochromic layer to the protective layer, and as a result the amount of substrate components remaining in the photochromic layer can be reduced. The inventors surmise that this is the reason why the decrease in light resistance can be significantly suppressed by performing the curing treatment for forming the protective layer by multi-stage light irradiation compared to when the curing treatment is performed by a single stage of light irradiation. Specific examples of the above-mentioned base material components include one or more of the following: release agents (e.g., acidic phosphate esters such as acidic alkyl phosphates), antioxidants (e.g., phenolic antioxidants), UV stabilizers (e.g., benzophenone compounds, benzotriazole compounds, etc.), and color inhibitors. However, the material is not limited to these. [Effects of the Invention]

[0009] According to one aspect of the present invention, it becomes possible to manufacture photochromic articles with excellent light resistance. [Modes for carrying out the invention]

[0010] The above manufacturing method will be explained in more detail below.

[0011] In the present invention and this specification, "photochromic article" refers to an article containing a photochromic compound. The photochromic compound is contained in the photochromic layer of the photochromic article produced by the above-described manufacturing method. A protective layer is provided on top of the photochromic layer. The protective layer can contribute, for example, to improving the durability of the photochromic article.

[0012] [Substrate] The photochromic articles manufactured by the above manufacturing method may, in one form, be optical articles. Optical articles include various articles such as eyeglass lenses, goggle lenses, sun visor visors, and helmet shield components. For example, the above photochromic article may have a photochromic layer and a protective layer on a substrate selected according to the type of optical article. As an example of a substrate, a plastic lens substrate or a glass lens substrate can be used as an eyeglass lens substrate. A glass lens substrate may be, for example, a lens substrate made of inorganic glass. As a lens substrate, a plastic lens substrate is preferred from the viewpoint of being lightweight, less prone to breakage, and easy to handle. Examples of plastic lens substrates include styrene resins such as (meth)acrylic resins, polycarbonate resins, allyl resins, allyl carbonate resins such as diethylene glycol bisallyl carbonate resin (CR-39), vinyl resins, polyester resins, polyether resins, urethane resins obtained by the reaction of isocyanate compounds with hydroxyl compounds such as diethylene glycol, thiourethane resins obtained by the reaction of isocyanate compounds with polythiol compounds, and cured products (generally called transparent resins) obtained by curing curable compositions containing (thio)epoxy compounds having one or more disulfide bonds in the molecule. The above "(meth)acrylic resin" includes acrylic resins and methacrylic resins. The above "(thio)epoxy compound" includes epoxy compounds and thioepoxy compounds. As lens substrates, undyed materials (colorless lenses) or dyed materials (dyed lenses) may be used. The refractive index of the lens substrate can be, for example, about 1.50 to 1.75. Polycarbonate resin is usually used as a lens substrate with a refractive index of 1.59. Allyl carbonate resins, such as allyl resin and diethylene glycol bisallyl carbonate resin (CR-39), are typically used as lens substrates with a refractive index of 1.50. Urea resins obtained by the reaction of isocyanate-terminated prepolymers with aromatic diamines are typically used as lens substrates with a refractive index of 1.53.A urethane resin obtained by reacting an isocyanate compound with a hydroxy compound such as diethylene glycol is usually used as a lens base material having a refractive index of 1.60. A thiourethane resin obtained by reacting an isocyanate compound with a polythiol compound is usually used as a base material having a refractive index of 1.67. According to studies by the present inventor, among the above resins, when a resin that is normally used as a lens base material with a refractive index of 1.59, a resin that is normally used as a lens base material with a refractive index of 1.53, that is, a polycarbonate resin and a urea resin obtained by reacting an isocyanate-terminated prepolymer with an aromatic diamine are used as the lens base material, it has been observed that performing the above curing treatment by multi-stage light irradiation tends to further improve the light resistance of the produced photochromic article. However, the refractive index of the lens base material is not limited to the above range, and may be within the above range or deviate upward or downward from the above range. In the present invention and the present specification, the refractive index refers to the refractive index for light with a wavelength of 500 nm. Further, the lens base material may be a lens having refractive power (a so-called prescription lens) or a lens having no refractive power (a so-called non-prescription lens).

[0013] The eyeglass lens may be various lenses such as a single focus lens, a multifocal lens, and a progressive power lens. The type of lens is usually determined by the surface shapes of both surfaces of the lens base material. Further, the surface of the lens base material may be convex, concave, or planar. In a conventional lens base material and an eyeglass lens, the object-side surface is convex and the eyeball-side surface is concave. However, the present invention is not limited thereto. The photochromic layer can usually be provided on the object-side surface of the lens base material, but may also be provided on the eyeball-side surface.

[0014] The photochromic layer may be provided directly on the surface of the base material, or may be provided indirectly via one or more other layers formed on the base material. An example of another layer is a primer layer for improving the adhesion between the photochromic layer and the base material.

[0015] [Photochromic Layer] <Photochromic Compound> Any known compound exhibiting photochromic properties can be used as the photochromic compound. The photochromic compound can, for example, exhibit photochromic properties in response to ultraviolet light. Examples of photochromic compounds include compounds with known photochromic skeletons such as flugimide compounds, spirooxazine compounds, chromene compounds, and indeno-condensed naphthopyran compounds. The photochromic compound can be used alone or in mixtures of two or more. The content of the photochromic compound can be, for example, about 0.1 to 15% by mass, based on 100% by mass of the photochromic layer, but is not limited to this range.

[0016] <Components for forming a photochromic layer> The photochromic layer may be a cured layer obtained by curing a polymerizable composition (polymerizable composition for photochromic layer formation) containing one or more photochromic compounds. In the present invention and this specification, "polymerizable compound" refers to a compound having one or more polymerizable groups in one molecule. Regarding the various components, such as polymerizable compounds, contained in the polymerizable composition for forming the photochromic layer, known technologies related to photochromic articles can be applied. From the viewpoint of adhesion to the protective layer, it is preferable that the photochromic layer is a cured layer obtained by curing a polymerizable composition containing (meth)acrylate as the polymerizable compound.

[0017] In one embodiment, the polymerizable composition for photochromic layer formation may contain at least the following component A and component B as polymerizable compounds.

[0018] (Component A) Component A is an acyclic methacrylate with a molecular weight of 500 or more. In this invention and specification, "acyclic" means that it does not contain a cyclic structure. An acyclic methacrylate refers to a monofunctional or higher methacrylate that does not contain a cyclic structure. It is presumed that component A may contribute to the photochromic layer exhibiting excellent weather resistance.

[0019] Component A can be a monofunctional or bifunctional or multifunctional methacrylate, preferably a bifunctional or trifunctional methacrylate, and more preferably a bifunctional methacrylate. An example of component A is polyalkylene glycol dimethacrylate. Polyalkylene glycol dimethacrylate is given by the following formula 1: [ka] This can be represented by R, where R represents an alkylene group and n represents the number of repeating alkoxy groups represented by RO, which is 2 or more. Examples of alkylene groups represented by R include ethylene groups, propylene groups, and tetramethylene groups. n is 2 or more and can be, for example, 30 or less, 25 or less, or 20 or less. Specific examples of polyalkylene glycol dimethacrylate include polyethylene glycol dimethacrylate, polypropylene glycol dimethacrylate, and polytetramethylene glycol dimethacrylate.

[0020] The molecular weight of component A is 500 or more. It is presumed that including an acyclic bifunctional methacrylate (component A) with a molecular weight of 500 or more, together with component B (details to be described later), contributes to the ability of photochromic compounds to develop a high concentration of color when irradiated with light in a photochromic layer formed from a polymerizable composition for photochromic layer formation containing these components. In the present invention and this specification, the molecular weight of the polymer is determined by the structural formula determined by structural analysis of the compound or by the theoretical molecular weight calculated from the raw material charge ratio during production. The molecular weight of component A is 500 or more, preferably 510 or more, more preferably 520 or more, preferably 550 or more, more preferably 570 or more, even more preferably 600 or more, even more preferably 630 or more, and even more preferably 650 or more. From the viewpoint of increasing the hardness of the photochromic layer, the molecular weight of component A is preferably, for example, 2000 or less, 1500 or less, 1200 or less, 1000 or less, or 800 or less.

[0021] (Component B) Component B is a bifunctional (meth)acrylate containing a structure selected from the group consisting of cyclic and branched structures. It is presumed that the inclusion of component B together with component A in a polymerizable composition for photochromic layer formation may contribute to the ability of photochromic compounds to develop color at high concentrations when irradiated with light in the photochromic layer formed from this composition. Furthermore, it is thought that component B may also contribute to increasing the solubility of photochromic compounds in such a composition. In one form, component B contains one or more cyclic structures but no branched structures in one molecule; in another form, it contains one or more branched structures but no cyclic structures; and in yet another form, it contains one or more cyclic structures and one or more branched structures in one molecule. The number of structures selected from the group consisting of cyclic and branched structures contained in one molecule is one or more, for example, one, two, or three, preferably one or two, and more preferably one. Regarding the branched structure, if component B has a methacryloyl group, the branched structure contained in the methacryloyl group is not considered.

[0022] Component B, which contains one or more cyclic structures, can in one form be an alicyclic difunctional (meth)acrylate. An alicyclic difunctional (meth)acrylate is, for example, R 1 -(L 1 )n1-Q-(L 2 )n2-R 2 It can be a compound having the structure represented by , where Q represents a divalent alicyclic group, and R 1 and R 2 Each of these independently represents either a (meth)acryloyl group or a (meth)acryloyloxy group, L 1 and L 2 Each of the 'n's independently represents a linking group, and n1 and n2 independently represent 0 or 1. The divalent alicyclic group represented by Q is preferably an alicyclic hydrocarbon group having 3 to 20 carbon atoms, such as cyclopentylene, cyclohexylene, cycloheptylene, cyclooctylene, tricyclodecaneylene, and adamantylene.1 and L 2 Examples of the linking group represented by include an alkylene group. The alkylene group may, for example, be an alkylene group having 1 to 6 carbon atoms.

[0023] Specific examples of alicyclic difunctional (meth)acrylates include cyclohexanedimethanol di(meth)acrylate, ethoxylated cyclohexanedimethanol di(meth)acrylate, propoxylated cyclohexanedimethanol di(meth)acrylate, ethoxylated propoxylated cyclohexanedimethanol di(meth)acrylate, tricyclodecanedimethanol di(meth)acrylate, ethoxylated tricyclodecanedimethanol di(meth)acrylate, propoxylated tricyclodecanedimethanol di(meth)acrylate, ethoxylated propoxylated tricyclodecanedimethanol di(meth)acrylate, and the like.

[0024] In one embodiment, component B containing one or more branched structures may be a difunctional (meth)acrylate containing a branched alkylene group. The number of carbon atoms in the branched alkylene group may be 1 or more, 2 or more, 3 or more, or 4 or more. Further, the number of carbon atoms in the branched alkylene group may be 10 or less, 9 or less, 8 or less, 7 or less, 6 or less, or 5 or less. In one embodiment, the branched alkylene group may contain a quaternary carbon (that is, a carbon bonded to four carbon atoms). Specific examples of component B containing one or more branched structures include neopentyl glycol di(meth)acrylate, ethoxylated neopentyl glycol di(meth)acrylate, propoxylated neopentyl glycol di(meth)acrylate, and the like.

[0025] The molecular weight of component B is not particularly limited, but in one embodiment, it may be, for example, in the range of 200 to 400. As the (meth)acryloyl group, component B may contain only an acryloyl group, may contain only a methacryloyl group, or may contain both an acryloyl group and a methacryloyl group.

[0026] The content of component A is preferably 50.0% by mass or more, more preferably 60.0% by mass or more, and even more preferably 70.0% by mass or more, relative to the total amount (100% by mass) of (meth)acrylate contained in the polymerizable composition for photochromic layer formation. Furthermore, the above content of component A can be, for example, 95.0% by mass or less, or 90.0% by mass or less. The polymerizable composition for photochromic layer formation may contain only one type of component A, or it may contain two or more types of component A. When two or more types of component A are included, the above content is the total content of those two or more types of component A. This also applies to the content of other components such as component B. In this invention and specification, a component that falls under either component A or component B shall be considered as component A. Component A may be the most abundant component among the (meth)acrylate contained in the polymerizable composition for photochromic layer formation. On the other hand, the content of component B can be 1.0% by mass or more, preferably 5.0% by mass or more, and more preferably 10.0% by mass or more, relative to the total amount (100% by mass) of (meth)acrylate contained in the polymerizable composition for photochromic layer formation. Furthermore, the above content of component B can be, for example, 30.0% by mass or less, and can also be 25.0% by mass or less or 20.0% by mass or less. The polymerizable composition for photochromic layer formation may or may not contain other (meth)acrylates other than components A and B. If the polymerizable composition for photochromic layer formation contains other (meth)acrylates other than components A and B, the content thereof is preferably 10.0% by mass or less, and more preferably 5.0% by mass or less, relative to the total amount (100% by mass) of (meth)acrylate contained in the polymerizable composition for photochromic layer formation. In one embodiment, the polymerizable composition for photochromic layer formation may contain only components A and B as (meth)acrylates. Furthermore, the polymerizable composition for photochromic layer formation may or may not contain polymerizable compounds other than (meth)acrylate.A polymerizable composition for photochromic layer formation may contain (meth)acrylate in a total amount of, for example, 80.0 to 99.9% by mass relative to the total amount (100% by mass) of the composition. In the present invention and this specification, with respect to content, "total amount of composition" refers to the total amount of all components excluding the solvent in the case of a composition containing a solvent. A polymerizable composition for photochromic layer formation may or may not contain a solvent. If a solvent is included, any solvent can be used in any amount, as long as it does not inhibit the progress of the polymerization reaction of the polymerizable composition.

[0027] (Other ingredients) A polymerizable composition for photochromic layer formation may contain one or more additives that are commonly found in polymerizable compositions, in any desired proportion. Examples of additives that may be included in a polymerizable composition for photochromic layer formation include polymerization initiators for promoting polymerization reactions.

[0028] For example, known polymerization initiators can be used as polymerization initiators, radical polymerization initiators are preferred, and it is more preferable to include only radical polymerization initiators as polymerization initiators. In addition, photopolymerization initiators or thermal polymerization initiators can be used as polymerization initiators, and photopolymerization initiators are preferred from the viewpoint of proceeding with the polymerization reaction in a short time. Examples of photoradical polymerization initiators include benzoin ketals such as 2,2-dimethoxy-1,2-diphenylethane-1-one; α-hydroxyketones such as 1-hydroxycyclohexylphenyl ketone, 2-hydroxy-2-methyl-1-phenylpropan-1-one, and 1-[4-(2-hydroxyethoxy)phenyl]-2-hydroxy-2-methyl-1-propan-1-one; α-aminoketones such as 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)-butan-1-one and 1,2-methyl-1-[4-(methylthio)phenyl]-2-morpholinopropan-1-one; oxime esters such as 1-[(4-phenylthio)phenyl]-1,2-octadione-2-(benzoyl)oxime; bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide, and bis(2,6-dimethoxybenzo Phosphine oxides such as 2-(o-chlorophenyl)-2,4,4-trimethylpentylphosphine oxide and 2,4,6-trimethylbenzoyldiphenylphosphine oxide; 2,4,5-triarylimidazole dimers such as 2-(o-chlorophenyl)-4,5-di(methoxyphenyl)imidazole dimer, 2-(o-fluorophenyl)-4,5-diphenylimidazole dimer, 2-(o-methoxyphenyl)-4,5-diphenylimidazole dimer, and 2-(p-methoxyphenyl)-4,5-diphenylimidazole dimer; benzophenone compounds such as benzophenone, N,N'-tetramethyl-4,4'-diaminobenzophenone, N,N'-tetraethyl-4,4'-diaminobenzophenone, and 4-methoxy-4'-dimethylaminobenzophenone;Quinone compounds such as 2-ethylanthraquinone, phenanthrenequinone, 2-tert-butylanthraquinone, octamethylanthraquinone, 1,2-benzanthraquinone, 2,3-benzanthraquinone, 2-phenylanthraquinone, 2,3-diphenylanthraquinone, 1-chloroanthraquinone, 2-methylanthraquinone, 1,4-naphthoquinone, 9,10-phenantraquinone, 2-methyl-1,4-naphthoquinone, and 2,3-dimethylanthraquinone; benzoin ethers such as benzoin methyl ether, benzoin ethyl ether, and benzoin phenyl ether; benzoin compounds such as benzoin, methylbenzoin, and ethylbenzoin; benzyl compounds such as benzyldimethylketal; acridine compounds such as 9-phenylacridine and 1,7-bis(9,9'-acridinylheptane); N-phenylglycine, coumarin, etc. Furthermore, in the 2,4,5-triarylimidazole dimer, the substituents on the aryl groups of the two triarylimidazole moieties may be identical and symmetric, or they may be different and asymmetric. Also, a thioxanthone compound may be combined with a tertiary amine, such as the combination of diethylthioxanthone and dimethylaminobenzoic acid. Among these, α-hydroxyketones and phosphine oxides are preferred from the viewpoint of curability, transparency, and heat resistance. The content of the polymerization initiator can be, for example, in the range of 0.1 to 5.0% by mass, based on 100% by mass of the total amount of the composition.

[0029] The polymerizable composition for photochromic layer formation contains one or more photochromic compounds. The photochromic compounds are as described above. The photochromic compound can be included in the polymerizable composition for photochromic layer formation alone, or it can be included in a mixture of two or more. The content of the photochromic compound in the polymerizable composition for photochromic layer formation can be, for example, about 0.1 to 15.0% by mass, based on 100% by mass of the total amount of the composition, but is not limited to this range. The polymerizable composition for photochromic layer formation can further contain any amount of known additives that are normally added to compositions containing photochromic compounds, such as surfactants, antioxidants, radical scavengers, light stabilizers, ultraviolet absorbers, color inhibitors, antistatic agents, fluorescent dyes, dyes, pigments, fragrances, plasticizers, silane coupling agents, etc. Known compounds can be used as these additives.

[0030] A polymerizable composition for forming a photochromic layer can be prepared, for example, by mixing the above-mentioned components simultaneously or sequentially in any order.

[0031] <Formation of photochromic layer> In one embodiment, the photochromic layer can be a cured layer obtained by curing a coated layer of a polymerizable composition (polymerizable composition for photochromic layer formation) containing one or more photochromic compounds. The coated layer can be formed by directly applying the photochromic layer formation composition to the surface of a substrate or by applying it to the surface of a layer provided on the substrate. An example of a layer provided on the substrate is a primer layer. As for the application method, known application methods such as spin coating and dip coating can be used, and spin coating is preferred from the viewpoint of uniformity of application. The polymerization treatment can be light irradiation and / or heat treatment, and light irradiation is preferred from the viewpoint of proceeding the polymerization reaction in a short time. The polymerization conditions should be determined according to the types and compositions of various components contained in the polymerizable composition. The thickness of the photochromic layer is preferably in the range of 5 to 80 μm, and more preferably in the range of 20 to 60 μm.

[0032] <Primer layer> In photochromic articles having a photochromic layer on a substrate, it is preferable to provide a primer layer between the substrate and the photochromic layer to improve adhesion between the substrate and the photochromic layer. The primer layer can be, for example, a cured layer obtained by curing a polymerizable composition for forming a primer layer.

[0033] In one embodiment, the polymerizable composition for primer layer formation may include a polyisocyanate, a hydroxyl group-containing polymerizable compound, and a polymerizable compound with a viscosity of 100 cP or less, selected from the group consisting of (meth)acrylates and vinyl ethers. The various components contained in the above polymerizable composition for primer layer formation will be described in more detail below.

[0034] (Polyisocyanate) The polymerizable composition for primer layer formation described above contains a polyisocyanate. A polyisocyanate is a compound having two or more isocyanate groups in one molecule. The number of isocyanate groups contained in one molecule of polyisocyanate is two or more, preferably three or more. The number of isocyanate groups contained in one molecule of polyisocyanate can be, for example, six or less, five or less, or four or less. The molecular weight of the polyisocyanate can be, for example, in the range of 100 to 500, but is not limited to this range. Specific examples of polyisocyanates include aromatic diisocyanates such as xylylene diisocyanate, phenylene diisocyanate, tolylene diisocyanate, diphenylmethane diisocyanate, and naphthalene diisocyanate, as well as aliphatic or alicyclic diisocyanates such as hexamethylene diisocyanate, lysine diisocyanate, cyclohexane diisocyanate, isophorone diisocyanate, 4,4'-dicyclohexylmethane diisocyanate, 1,3-bisisocyanatomethylcyclohexane, and tetramethylxylylene diisocyanate. Furthermore, allophanates, adducts, biuret compounds, and isocyanurates of the polyisocyanates exemplified above can also be mentioned. Commercially available polyisocyanates include Coronate HX, Coronate HXR, Coronate HXLV, Coronate HK, Coronate 2715, Coronate HL, Coronate L, Coronate 2037, HDI, TDI, MDI (manufactured by Tosoh Corporation), Takenate 500, Takenate 600, Duranate 24A-100, TPA-100, TKA-100, P301-75E, Takenate D-110N, D-120N, D-127N, D-140N, D-160N, D15N, D-170N, D-170HN, D-172N, D-177N, D-178N, and D-101E (manufactured by Mitsui Chemicals Corporation).

[0035] (Hydroxy group-containing polymerizable compound) The polymerizable composition for forming the primer layer described above contains a hydroxyl group-containing polymerizable compound. The number of hydroxyl groups contained in one molecule of the hydroxyl group-containing polymerizable compound is preferably 1 or more, and more preferably 2 or more. Furthermore, the number of hydroxyl groups contained in one molecule of the hydroxyl group-containing polymerizable compound is preferably 4 or less, and more preferably 3 or less. By reacting the isocyanate groups of the polyisocyanate with the hydroxyl groups of the hydroxyl group-containing polymerizable compound, a urethane bond can be formed. It is presumed that this urethane bond contributes to the primer layer functioning as a layer for improving adhesion.

[0036] A hydroxyl group-containing polymerizable compound may have one or more polymerizable groups in one molecule, and preferably two or more. In one form, the hydroxyl group-containing polymerizable compound may be a (meth)acrylate.

[0037] When the hydroxyl group-containing polymerizable compound is a (meth)acrylate, the number of functionalities as a (meth)acrylate is 1 or more (i.e., monofunctional or greater), and preferably 2 or more. Furthermore, it is preferable that the number of functionalities is 3 or less. The hydroxyl group-containing polymerizable compound may contain only an acryloyl group as the (meth)acryloyl group, only a methacryloyl group, or both an acryloyl group and a methacryloyl group. In one embodiment, it is preferable that the hydroxyl group-containing polymerizable compound contains only an acryloyl group as the (meth)acryloyl group. The molecular weight of the hydroxyl group-containing polymerizable compound can be, for example, in the range of 300 to 400, but is not limited to this range. Specific examples of polymerizable compounds containing hydroxyl groups include 2-hydroxyethyl (meth)acrylate, Hydroxypropyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, 1,4-cyclohexanedimethanol monoacrylate, 2-hydroxy-1-acryloxy-3-methadryloxypropane, 2-hydroxy 1-3-dimethacryloxypropane, pentaerythritol tetraacrylate, 2-hydroxy-3-phenoxypropyl acrylate, monoacryloxyethyl hexahydrophthalate, 2-acryloyloxyethyl phthalate, and 2-(acryloxyoxy)ethyl 2-hydroxyethyl phthalate. In one embodiment, polymerizable compounds containing hydroxyl groups may also have an amide group. Specific examples of polymerizable compounds containing hydroxyl groups that have an amide group include, for example, N-(2-hydroxyethyl)acrylamide. In one embodiment, polymerizable compounds containing hydroxyl groups may also have an epoxy ester structure. An epoxy ester structure is a structure produced by the reaction of an epoxy group and a carboxyl group, and can be represented as "-CH(OH)-CH2-OC(=O)-".Examples of commercially available polymerizable compounds containing hydroxyl groups and having an epoxy ester structure include epoxy ester 40EM (manufactured by Kyoeisha Chemical Co., Ltd.), epoxy ester 70PA (manufactured by Kyoeisha Chemical Co., Ltd.), epoxy ester 80MFA (manufactured by Kyoeisha Chemical Co., Ltd.), epoxy ester 200PA (manufactured by Kyoeisha Chemical Co., Ltd.), epoxy ester 3002M(N) (manufactured by Kyoeisha Chemical Co., Ltd.), epoxy ester 3002A(N) (manufactured by Kyoeisha Chemical Co., Ltd.), epoxy ester 3000MK (manufactured by Kyoeisha Chemical Co., Ltd.), epoxy ester 3000A (manufactured by Kyoeisha Chemical Co., Ltd.), and the like.

[0038] (A polymerizable compound selected from the group consisting of (meth)acrylates and vinyl ethers, with a viscosity of 100 cP or less.) The polymerizable composition for primer layer formation described above has a viscosity of 100 cP (centipoise) or less and contains a polymerizable compound selected from the group consisting of (meth)acrylate and vinyl ether. It is presumed that the inclusion of such a low-viscosity polymerizable compound contributes to suppressing the occurrence of optical defects in the primer layer formed from the polymerizable composition for primer layer formation containing polyisocyanate and a hydroxyl group-containing polymerizable compound. In the present invention and this specification, "viscosity" is a value measured by a vibrating viscometer in an atmospheric atmosphere at a temperature of 25°C. The viscosity of the polymerizable compound described above is 100 cP or less, preferably 70 cP or less, and more preferably 50 cP or less. The viscosity of the polymerizable compound described above can also be, for example, 5 cP or more or 10 cP or more. The (meth)acrylate, which is one form of the polymerizable compound described above, can be monofunctional to trifunctional, and preferably monofunctional to bifunctional. The (meth)acrylate, which is one form of the polymerizable compound described above, can also contain aryl groups (e.g., phenyl groups), amide groups, etc. In the present invention and this specification, "vinyl ether" refers to a compound having one or more vinyl groups and one or more ether bonds in one molecule, preferably having two or more vinyl groups in one molecule, and more preferably having two to four. Furthermore, the number of ether bonds contained in the vinyl ether is preferably two to four in one molecule. The molecular weight of the above polymerizable compound can be, for example, in the range of 150 to 250, but is not limited to this range. Specific examples of the above polymerizable compound include 2-phenoxyethyl (meth)acrylate, acrylamide, methoxypolyethylene glycol (meth)acrylate, phenoxypolyethylene glycol (meth)acrylate, stearyl (meth)acrylate, 1,10-decanediol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, 1,9-Nonanediol di(meth)acrylate, dipropylene glycol di(meth)acrylate, tripropylene glycol di(meth)acrylate, polypropylene glycol di(meth)acrylate, phenoxyethyl (meth)acrylate, ethylene glycol di(meth)acrylate, diethylene glycol di(meth)acrylate, triethylene glycol di(meth)acrylate, tricyclodecane dimethanol di(meth)acrylate, ethoxylated polypropylene glycol di(meth)acrylate, trimethylolpropane tri(meth)acrylate, ethyl (meth)acrylate, butyl (meth)acrylate, isobutyl (meth)acrylate, tert-butyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, isodecyl (meth)acrylate, dodecyl (meth)acrylate, tri Decyl (meth)acrylate, diethylene glycol butyl ether (meth)acrylate, cyclohexyl (meth)acrylate, tetrahydrofurfuryl (meth)acrylate, benzyl (meth)acrylate, 2-phenoxyethyl (meth)acrylate, isobornyl (meth)acrylate, 2-(dimethylamino)ethyl (meth)acrylate, 2-(diethylamino)ethyl (meth)acrylate, glycidyl (meth)acrylate, ethylene glycol di(meth)acrylate, diethylene glycol di(meth)acrylate, triethylene glycol di(meth)acrylate, polyethylene glycol di(meth)acrylate, tetramethylene glycol di(meth)acrylate, neopentyl glycol di(meth)acrylate, hexanediol di(meth)acrylate, nonamethylene glycol di(meth)acrylate, isoamyl Examples include (meth)acrylate, ethylene glycol monovinyl ether, tetramethylene glycol monovinyl ether, diethylene glycol monovinyl ether, 2-ethylhexyl vinyl ether, 2-propenoic acid, 2-[2-(ethenyloxy)ethoxy]ethyl ester, 2-(2-ethenoxyethoxy)ethyl 2-methylprop-2-enoate, etc.

[0039] In the polymerizable composition for primer layer formation described above, the content of a polymerizable compound selected from the group consisting of (meth)acrylate and vinyl ether, having a viscosity of 100 cP or less, is preferably 30.0% by mass or more, and more preferably 40.0% by mass or more, based on the total of such polymerizable compound, polyisocyanate, and hydroxyl group-containing polymerizable compound being 100% by mass. The content of a polymerizable compound selected from the group consisting of (meth)acrylate and vinyl ether, having a viscosity of 100 cP or less, can be, for example, 90.0% by mass or less, 80.0% by mass or less, or 70.0% by mass or less, based on the total of such polymerizable compound, polyisocyanate, and hydroxyl group-containing polymerizable compound being 100% by mass. In one embodiment, the polymerizable compound selected from the group consisting of (meth)acrylate and vinyl ether, having a viscosity of 100 cP or less, is preferably the component that is most abundant in the polymerizable composition for primer layer formation described above, among such polymerizable compound, polyisocyanate, and hydroxyl group-containing polymerizable compound.

[0040] In the polymerizable composition for forming the primer layer described above, the polyisocyanate content is preferably 70.0% by mass or less, more preferably 60.0% by mass or less, and even more preferably 50.0% by mass or less, based on 100% by mass of the total polymerizable compounds selected from the group consisting of polyisocyanate, hydroxyl group-containing polymerizable compounds, and polymerizable compounds selected from the group consisting of (meth)acrylate and vinyl ether with a viscosity of 100 cP or less. The polyisocyanate content can be, for example, 10.0% by mass or more, 20.0% by mass or more, or 30.0% by mass or more, based on 100% by mass of the total polymerizable compounds selected from the group consisting of polyisocyanate, hydroxyl group-containing polymerizable compounds, and polymerizable compounds selected from the group consisting of (meth)acrylate and vinyl ether with a viscosity of 100 cP or less.

[0041] In the polymerizable composition for forming the primer layer described above, the content of the hydroxyl group-containing polymerizable compound is preferably 3.0% by mass or more, more preferably 5.0% by mass or more, and even more preferably 7.0% by mass or more, based on 100% by mass of the total polymerizable compound selected from the group consisting of polyisocyanate, hydroxyl group-containing polymerizable compound, and polymerizable compound selected from the group consisting of (meth)acrylate and vinyl ether with a viscosity of 100 cP or less. The content of the hydroxyl group-containing polymerizable compound can be, for example, 30.0% by mass or less or 20.0% by mass or less, based on 100% by mass of the total polymerizable compound selected from the group consisting of polyisocyanate, hydroxyl group-containing polymerizable compound, and polymerizable compound selected from the group consisting of (meth)acrylate and vinyl ether with a viscosity of 100 cP or less.

[0042] The polymerizable composition for forming the primer layer described above may further contain a polymerization initiator. The polymerizable composition for forming the primer layer may contain a polymerization initiator in a concentration of, for example, 0.01 to 3.0% by mass, with the total amount of polyisocyanate, a hydroxyl group-containing polymerizable compound, and a polymerizable compound selected from the group consisting of (meth)acrylate and vinyl ether with a viscosity of 100 cP or less being 100% by mass.

[0043] As the polymerization initiator, known polymerization initiators can be used, radical polymerization initiators are preferred, and it is more preferable to include only radical polymerization initiators as the polymerization initiator. In addition, as the polymerization initiator, photopolymerization initiators or thermal polymerization initiators can be used, and photopolymerization initiators are preferred from the viewpoint of proceeding the polymerization reaction in a short time. For specific examples of photoradical polymerization initiators, refer to the previous description regarding polymerization initiators that may be included in polymerizable compositions for photochromic layer formation.

[0044] The polymerizable composition for forming the primer layer described above may or may not contain a solvent. If a solvent is included, any solvent can be used as long as it does not inhibit the polymerization reaction of the polymerizable composition. When a solvent is included, the solvent content is preferably 10.0% by mass or less, more preferably 5.0% by mass or less, and even more preferably 3.0% by mass or less, with the total of polyisocyanate, hydroxyl group-containing polymerizable compound, and polymerizable compound selected from the group consisting of (meth)acrylate and vinyl ether with a viscosity of 100 cP or less being 100% by mass.

[0045] The above polymerizable composition for primer layer formation may further contain any amount of known additives that can be commonly added to compositions for primer layer formation. Known compounds can be used as additives. The above polymerizable composition for primer layer formation may contain, with the total amount of the composition (excluding the polymerization initiator) being 100% by mass, a total of 80.0% or more by mass, 85.0% or more by mass, 90.0% or more by mass, or 95.0% or more by mass of polyisocyanate, a hydroxyl group-containing polymerizable compound, and a polymerizable compound selected from the group consisting of (meth)acrylate and vinyl ether, having a viscosity of 100 cP or less. Furthermore, in the polymerizable composition for primer layer formation described above, with the total amount of the composition (excluding the polymerization initiator) being 100% by mass, the total content of polyisocyanate, hydroxyl group-containing polymerizable compounds, and polymerizable compounds selected from the group consisting of (meth)acrylate and vinyl ether with a viscosity of 100 cP or less can be, for example, 100% by mass, 100% by mass or less, less than 100% by mass, 99.0% by mass or less, or 98.0% by mass or less.

[0046] The polymerizable composition for primer layer formation described above can be prepared by mixing the various components described above simultaneously or sequentially in any order.

[0047] A primer layer, which is a cured layer of the polymerizable composition for primer layer formation, can be formed on the substrate by applying a polymerizable composition for primer layer formation to a substrate and then curing the applied composition. Known application methods such as spin coating and dip coating can be used, and spin coating is preferred from the viewpoint of uniformity of application. The curing treatment can be light irradiation and / or heat treatment, and light irradiation is preferred from the viewpoint of proceeding the curing reaction in a short time. The curing treatment conditions should be determined according to the types of various components contained in the polymerizable composition for primer layer formation and the composition of the polymerizable composition for primer layer formation. After the curing treatment, annealing (heat treatment) can be performed as needed. Annealing can be performed, for example, in a heat treatment furnace with an ambient temperature of about 90 to 130°C.

[0048] The thickness of the primer layer can be, for example, 3 μm or more, and preferably 5 μm or more. Alternatively, the thickness of the primer layer can be, for example, 15 μm or less, and preferably 10 μm or less.

[0049] [Protective layer] In the above manufacturing method, a protective layer, which is a cured layer obtained by curing a polymerizable composition for forming a protective layer, is formed on the photochromic layer. The protective layer can be provided directly on the surface of the photochromic layer, or it can be provided on the surface of a layer located above the photochromic layer. Examples of layers that may be located between the photochromic layer and the protective layer include a primer layer. The thickness of the protective layer is preferably 10 μm or more, more preferably 15 μm or more, even more preferably 20 μm or more, and even more preferably 25 μm or more. Furthermore, the thickness of the protective layer is preferably 45 μm or less, and more preferably 40 μm or less. The above protective layer can contribute to improving the durability of the photochromic article, for example. It can also protect the photochromic layer until further processing (for example, the formation of a hard coat layer as described later) is performed, thereby suppressing the occurrence of scratches on the photochromic layer.

[0050] <Polymerizable composition for forming protective layer> ((meth)acrylate) The polymerizable composition for forming a protective layer contains one or more polymerizable compounds. The polymerizable compound is preferably a compound having polymerizable groups that can undergo polymerization upon light irradiation, and more preferably a (meth)acrylate.

[0051] In this invention and specification, "(meth)acrylate" is used to encompass both acrylate and methacrylate. "Acrylate" is a compound having one or more acryloyl groups in one molecule. "Methacrylate" is a compound having one or more methacryloyl groups in one molecule. For (meth)acrylate, the functional number is the number of groups selected from the group consisting of acryloyl groups and methacryloyl groups contained in one molecule. In this invention and specification, "methacrylate" refers to a compound containing only methacryloyl groups as (meth)acryloyl groups, while a compound containing both acryloyl groups and methacryloyl groups as (meth)acryloyl groups is called acrylate. Acryloyl groups may be contained in the form of acryloyloxy groups, and methacryloyl groups may be contained in the form of methacryloyloxy groups. In the following, "(meth)acryloyl group" is used to encompass both acryloyl and methacryloyl groups, and "(meth)acryloyloxy group" is used to encompass both acryloyloxy and methacryloyloxy groups. Unless otherwise specified, the groups described may or may not have substituents. If a group has substituents, examples of substituents include alkyl groups (e.g., alkyl groups with 1 to 6 carbon atoms), hydroxyl groups, alkoxy groups (e.g., alkoxy groups with 1 to 6 carbon atoms), halogen atoms (e.g., fluorine, chlorine, bromine atoms), cyano groups, amino groups, nitro groups, acyl groups, carboxyl groups, etc. For groups with substituents, "number of carbon atoms" refers to the number of carbon atoms in the part that does not contain the substituent.

[0052] In one embodiment, the polymerizable composition for forming a protective layer may contain an alicyclic difunctional (meth)acrylate. An "alicyclic difunctional (meth)acrylate" refers to a compound having an alicyclic structure and containing two (meth)acryloyl groups in one molecule.

[0053] Alicyclic bifunctional (meth)acrylates are, for example, R 1 -(L 1 )n1-Q-(L 2 )n2-R 2 It can be a compound having the structure represented by , where Q represents a divalent alicyclic group, and R 1 and R 2 Each of these independently represents either a (meth)acryloyl group or a (meth)acryloyloxy group, L 1 and L 2 Each of the following independently represents a linking group, and n1 and n2 independently represent 0 or 1. The divalent alicyclic group represented by Q is preferably an alicyclic hydrocarbon group having 3 to 20 carbon atoms, such as cyclopentylene, cyclohexylene, cycloheptylene, cyclooctylene, tricyclodecanylene, adamantylene, and isobornyl. 1 and L 2 Examples of linking groups represented by this formula include alkylene groups. These alkylene groups can be, for example, alkylene groups having 1 to 6 carbon atoms.

[0054] Specific examples of alicyclic difunctional (meth)acrylates include, for example, cyclohexanedimethanol di(meth)acrylate, ethoxylated cyclohexanedimethanol di(meth)acrylate, propoxylated cyclohexanedimethanol di(meth)acrylate, ethoxylated propoxylated cyclohexanedimethanol di(meth)acrylate, tricyclodecanedimethanol di(meth)acrylate, ethoxylated tricyclodecanedimethanol di(meth)acrylate, propoxylated tricyclodecanedimethanol di(meth)acrylate, and ethoxylated propoxylated tricyclodecanedimethanol di(meth)acrylate. The molecular weight of alicyclic difunctional (meth)acrylates can be in the range of, for example, 200 to 400, but is not limited to this range. The alicyclic bifunctional (meth)acrylate may contain only an acryloyl group, only a methacryloyl group, or both an acryloyl and a methacryloyl group as the (meth)acryloyl group.

[0055] A polymerizable composition for forming a protective layer may contain, for example, 70.0% or more, 75.0% or more, 80.0% or more, 85.0% or more, 90.0% or more, or 95.0% or more of alicyclic difunctional (meth)acrylates, with the total amount of (meth)acrylates contained in the composition being 100% by mass. In one embodiment, the polymerizable composition for forming a protective layer may contain alicyclic difunctional (meth)acrylates as the total amount of (meth)acrylates contained in the composition. In one embodiment, the polymerizable composition for forming a protective layer may contain only one type of alicyclic difunctional (meth)acrylate, while in another embodiment, it may contain two or more types. When two or more types of alicyclic difunctional (meth)acrylates are included, the content of the above-mentioned alicyclic difunctional (meth)acrylates is the total content of the two or more types. This also applies to the content of other components.

[0056] In one embodiment, the polymerizable composition for forming a protective layer may consist entirely of alicyclic difunctional (meth)acrylates. In another embodiment, it may contain one or more other (meth)acrylates in addition to alicyclic difunctional (meth)acrylates. In yet another embodiment, it may contain one or more other (meth)acrylates but not alicyclic difunctional (meth)acrylates. As the other (meth)acrylates mentioned above, one or more of the various (meth)acrylates can be used. Examples of other (meth)acrylates include monofunctional, difunctional, trifunctional, tetrafunctional, and pentafunctional (meth)acrylates, which may be acyclic or cyclic. "Acyclic" means not containing a cyclic structure. "Cyclic" means containing a cyclic structure. A (meth)acrylate containing a cyclic structure may have an alicyclic structure as its cyclic structure, or it may have other cyclic structures. For alicyclic structures, refer to the previous description concerning alicyclic difunctional (meth)acrylates. In a polymerizable composition for forming a protective layer, the content of other (meth)acrylates can be, for example, 30.0% by mass or less, 25.0% by mass or less, 20.0% by mass or less, or 15.0% by mass or less, based on the total amount of (meth)acrylates contained in this composition as 100% by mass. In addition, in a polymerizable composition for forming a protective layer, the content of other (meth)acrylates can be, for example, 0% by mass, 0% by mass or more, greater than 0% by mass, 1.0% by mass or more, 5.0% by mass or more, or 10.0% by mass or more, based on the total amount of (meth)acrylates contained in this composition as 100% by mass.

[0057] (Other ingredients) A polymerizable composition for forming a protective layer may, in one form, contain only (meth)acrylate as the polymerizable compound, and in another form, contain (meth)acrylate along with one or more other polymerizable compounds other than (meth)acrylate as the polymerizable compound. There are no particular restrictions on the other polymerizable compounds, and one or more known polymerizable compounds can be used. For example, a polymerizable composition for forming a protective layer may contain 80.0% by mass or more, 85.0% by mass or more, 90.0% by mass or more, or 95.0% by mass or more of (meth)acrylate, with the total amount of polymerizable compounds in the composition being 100% by mass, and the total amount of polymerizable compounds may also be (meth)acrylate.

[0058] In one embodiment, the polymerizable composition for forming a protective layer preferably has a (meth)acrylate content (total content if two or more types of (meth)acrylates are included) of 80.0% by mass or more, more preferably 85.0% by mass or more, even more preferably 90.0% by mass or more, and most preferably 95.0% by mass or more, based on the total amount of the composition as 100% by mass. In the present invention and this specification, with respect to content, "total amount of composition" means the total amount of all components excluding the solvent in the case of a composition containing a solvent. The polymerizable composition for forming a protective layer may or may not contain a solvent. If a solvent is included, any solvent can be used in any amount, as long as it does not inhibit the progress of the polymerization reaction of the polymerizable composition.

[0059] A polymerizable composition for forming a protective layer may contain one or more of the various additives that can be included in polymerizable compositions in any desired proportion. Examples of such additives include known additives such as polymerization initiators for promoting polymerization reactions and leveling agents for improving the coating suitability of the composition.

[0060] For example, known polymerization initiators capable of functioning as polymerization initiators for (meth)acrylates can be used as polymerization initiators, radical polymerization initiators are preferred, and it is more preferable to include only radical polymerization initiators as polymerization initiators. In addition, photopolymerization initiators can be used as polymerization initiators. For specific examples of photoradical polymerization initiators, refer to the previous description regarding polymerization initiators that may be included in polymerizable compositions for photochromic layer formation. The content of the polymerization initiator can be in the range of, for example, 0.1 to 5.0% by mass, with the total amount of the polymerizable composition for protective layer formation being 100% by mass.

[0061] In one embodiment, the polymerizable composition for forming the protective layer may contain an ultraviolet absorber. As UV absorbers, one or more of the following UV absorbers can be used: for example, hydroxyphenyl triazine compounds such as 2,4-bis(2,4-dimethylphenyl)-6-(2-hydroxy-4-n-octyloxyphenyl)-s-triazine, 2,4,6-tris(2-hydroxy-4-hexyloxy-3-methylphenyl)-s-triazine, 2-[2-hydroxy-4-(2-ethylhexyloxy)phenyl]-4,6-dibiphenyl-s-triazine, and 2-[[2-hydroxy-4-[1-(2-ethylhexyloxycarbonyl)ethyloxy]phenyl]]-4,6-diphenyl-s-triazine, as well as benzotriazole-based UV absorbers such as 2-(5-chloro-2H-benzotriazol-2-yl)-6-tert-butyl-4-methylphenol and 2-(5-chloro-2-benzotriazolyl)-6-tert-butyl-p-cresol. The inclusion of an ultraviolet absorber in a polymerizable composition for forming a protective layer can contribute to improving the weather resistance of a photochromic article having a protective layer formed from this composition. When a polymerizable composition for forming a protective layer contains an ultraviolet absorber, the content of the ultraviolet absorber can be in the range of, for example, 0.1 to 1.0% by mass, based on 100% by mass of the total amount of the composition.

[0062] A polymerizable composition for forming a protective layer can be prepared by mixing the various components described above simultaneously or sequentially in any order.

[0063] <Application of polymerizable composition for forming a protective layer> The polymerizable composition for forming the protective layer can be applied directly to the surface of the photochromic layer, or to the surface of a layer located above the photochromic layer. Known application methods such as spin coating and dip coating can be used, and spin coating is preferred from the viewpoint of uniformity of application.

[0064] <Hardening treatment> The above coating process forms a coating layer of the protective layer-forming composition directly on the photochromic layer or via one or more other layers. In the above manufacturing method, the curing treatment of the coating layer is performed by multi-stage light irradiation. In the present invention and this specification, the curing treatment performed by multi-stage light irradiation involves multiple light irradiations, and each light irradiation is performed at a time interval from the end of the immediately preceding light irradiation. The inventors surmise that forming a cured layer of the polymerizable composition for protective layer formation by performing multi-stage light irradiation in this manner contributes to improving the light resistance of the photochromic article. Details of this point are as described above.

[0065] The multi-stage light irradiation described above consists of two or more stages of light irradiation, and in one form, it can consist of two stages of light irradiation. In two-stage light irradiation, the total number of light irradiations is two, and there is a time interval between the first and second light irradiations. In another form, the multi-stage light irradiation can consist of three or more stages of light irradiation. That is, the total number of light irradiations in multi-stage light irradiation is two or more, and can also be three or more. In one form, the total number of irradiations can be, for example, five or fewer, or four or fewer.

[0066] The light irradiated onto the coated layer of the polymerizable composition for forming the protective layer by the above-mentioned light irradiation can be any light with a wavelength capable of promoting the photopolymerization reaction of the polymerizable composition for forming the protective layer, such as ultraviolet light. In the present invention and this specification, "ultraviolet light" refers to electromagnetic waves with wavelengths in the range of 200 to 420 nm.

[0067] In multi-stage light irradiation, each of the multiple light irradiations can be performed under the same or different irradiation conditions. The irradiation conditions should be set appropriately according to the type and composition of components contained in the polymerizable composition for forming the protective layer, the thickness of the coated layer, etc. When ultraviolet irradiation is used as the light irradiation, the ultraviolet irradiance should be, for example, 180 to 280 mW / cm². 2 It can be in the range of 220-280 mW / cm². 2 It is preferable to set the range to 240-260 mW / cm². 2 It is more preferable to set the range to the above. However, the above range is merely illustrative, and the present invention is not limited to such examples. Each light irradiation can be performed for, for example, 1 to 40 seconds. The total light irradiation time in multi-stage light irradiation can be, for example, 5 to 60 seconds. In multi-stage light irradiation, the irradiation times of multiple light irradiations can be the same or different. In one embodiment, the light irradiation performed earlier can be performed for a shorter time. For example, if multi-stage light irradiation is two-stage light irradiation, the irradiation time of the first light irradiation can be shorter than the irradiation time of the second light irradiation. In one embodiment, it is preferable to set the irradiation time of the first light irradiation to 1 to 5 seconds and the irradiation time of the second light irradiation to 15 to 35 seconds, and it is more preferable to set the irradiation time of the first light irradiation to 1 to 3 seconds and the irradiation time of the second light irradiation to 20 to 30 seconds. When three or more light irradiations are performed in multi-stage light irradiation, the irradiation time of each light irradiation from the third time onward can be the same or different from the irradiation time of the second light irradiation.

[0068] Light irradiation can be carried out by placing the object to be irradiated (i.e., a laminate including at least a substrate, a photochromic layer, and a coating layer of a polymerizable composition for forming a protective layer) inside a light irradiation device. Examples of the atmosphere inside the light irradiation device include a nitrogen atmosphere and an atmospheric atmosphere. The above-mentioned nitrogen atmosphere and the nitrogen atmosphere described later can be, for example, a nitrogen atmosphere with an oxygen concentration of 500 ppm or less (ppm is on a volume basis). The atmosphere inside the device can be made into a nitrogen atmosphere by purging with nitrogen. From the viewpoint of ensuring that the curing reaction proceeds well, it is preferable to carry out the first light irradiation in a nitrogen atmosphere among multiple light irradiations. Subsequent light irradiations can be carried out in a nitrogen atmosphere, or in an atmosphere other than a nitrogen atmosphere (for example, an atmospheric atmosphere).

[0069] In multi-stage light irradiation, the time interval between one light irradiation and the next can be, for example, 30 minutes to 1 day, preferably 30 minutes to 6 hours, and more preferably 30 minutes to 3 hours. The atmosphere in which the irradiated object is placed during the above time interval can be an atmospheric atmosphere, a nitrogen atmosphere, etc. Furthermore, the atmosphere in which the irradiated object is placed may be changed during the above time interval. For example, it can be changed from a nitrogen atmosphere to an atmospheric atmosphere.

[0070] In a multi-stage light irradiation process, each irradiation can, in one embodiment, be performed within the same light irradiation apparatus that performed the previous irradiation. In another embodiment, after the completion of the previous irradiation, the object to be irradiated can be removed from the apparatus and then placed back into the same apparatus for further irradiation. For example, a visual inspection can be performed on the object to be irradiated after it has been removed from the light irradiation apparatus. For example, if the visual inspection is satisfactory, the next irradiation can be performed; if it is unsatisfactory, the object can be discarded or subjected to processing for reuse without being subjected to the next irradiation. A specific example of processing for reuse is the process of peeling off some or all of the layers formed on the substrate (hereinafter also referred to as "film peeling"). Film peeling can be performed more easily before the curing process for protective layer formation is completed compared to after it has been completed. Therefore, it is preferable to perform a visual inspection between one irradiation and the next during the curing process using multi-stage light irradiation. By performing various treatments (for example, the formation of the layer described above) after the film removal process, the amount of waste discarded as defective products in the manufacturing process of photochromic articles can be reduced. In one configuration, after the completion of the previous light irradiation, the object to be irradiated can be held inside the device, and after a predetermined time has elapsed, light irradiation can be performed again inside the same device. In another configuration, each stage of light irradiation in a multi-stage light irradiation process can be performed using a different light irradiation device than the one used for the previous stage.

[0071] [Possible layers to be added at will] The photochromic article manufactured by the above manufacturing method has a layer structure of "substrate / photochromic layer / protective layer". Regarding the layer structure, " / " is used to encompass both forms in which the layers are in direct contact without other layers and forms in which they are provided through one or more other layers. For example, a primer layer may exist between the substrate and the photochromic layer as described above, but the substrate and the photochromic layer may also be in direct contact. In one embodiment, the above photochromic article may have a layer structure of "substrate / photochromic layer / protective layer / other cured layer". In such a layer structure, the other cured layer may be a cured layer generally called a hard coat layer. By providing a hard coat layer in addition to the protective layer, the durability of the photochromic article can be further enhanced. In one embodiment, the impact resistance of the photochromic article can also be enhanced by providing a hard coat layer. In one embodiment, the above other cured layer may be in direct contact with the protective layer without other layers in between.

[0072] The thickness of the other cured layer can be, for example, in the range of 1 to 10 μm, preferably in the range of 1 to 8 μm, and more preferably in the range of 1 to 5 μm. In one embodiment, the other cured layer can be a thinner layer than the protective layer. An example of the other cured layer is an organosilicon-based cured layer. Organosilicon-based cured layers are preferred because they generally have excellent impact resistance. Furthermore, if an anti-reflective layer is provided, for example, the organosilicon-based cured layer is also preferred because it generally has excellent adhesion to the anti-reflective layer.

[0073] An organosilicon-based cured layer is a cured layer obtained by curing a polymerizable composition containing an organosilicon compound. Examples of organosilicon compounds include organosilicon compounds that can generate silanol groups by polymerization treatment, and organopolysiloxanes having reactive groups such as halogen atoms or amino groups that condense with silanol groups. Other examples of organosilicon compounds include silane coupling agents having polymerizable groups such as vinyl groups, allyl groups, (meth)acryloyl groups, and (meth)acryloyloxy groups, and hydrolyzable groups such as alkoxy groups. Polymerizable compositions containing organosilicon compounds may contain particles of inorganic substances such as silicon oxides and titanium oxides for purposes such as adjusting the refractive index. For details of polymerizable compositions containing organosilicon compounds, known technologies relating to organosilicon-based cured layers that can function as hard coat layers can be applied. Such polymerizable compositions can be cured by proceeding with polymerization reactions by light irradiation and / or heat treatment, depending on the types of components contained in the composition.

[0074] Before applying the other curing layer on top of the protective layer, the cleanliness of the protective layer surface to which the polymerizable composition for forming the other curing layer will be applied can be increased by wiping the protective layer surface with a solvent. Performing this solvent wiping treatment is preferable from the viewpoint of preventing foreign matter from being interposed between the protective layer and the other curing layer.

[0075] The solvent-based wiping treatment can be carried out by known methods. For example, the solvent-based wiping treatment can be performed by wiping the surface of the protective layer with a cloth impregnated with a solvent. Examples of solvents include ketone solvents such as acetone, and alcohol solvents such as ethanol and isopropyl alcohol. In one embodiment, it is preferable that the protective layer has high resistance to ketone solvents, which are commonly used as wiping solvents in the manufacture of optical articles.

[0076] The above-mentioned photochromic articles may have one or more additional layers in addition to the various layers described above. Examples of such layers include layers known as functional layers for optical articles, such as anti-reflective layers, water-repellent or hydrophilic anti-fouling layers, and anti-fogging layers.

[0077] One form of the above-mentioned photochromic article is an eyeglass lens. Other forms of the above-mentioned photochromic article include lenses for goggles, visors for sun visors, and shield components for helmets. The above-mentioned photochromic article can be suitably used as an optical article having an anti-glare function.

[0078] By combining the above-mentioned spectacle lenses with a frame, eyeglasses can be manufactured. Such eyeglasses, equipped with photochromic spectacle lenses, can, for example, provide an anti-glare effect like sunglasses outdoors, as the photochromic compound contained in the photochromic layer changes color upon exposure to sunlight, and upon returning indoors, the photochromic compound fades, restoring transparency. Regarding the construction of the frames and other components of the eyeglasses, known technologies can be applied. [Examples]

[0079] The present invention will be further described below with reference to examples. However, the present invention is not limited to the embodiments shown in the examples. Unless otherwise specified, the processes and evaluations described below were carried out in air at room temperature (20°C ± 5°C).

[0080] [Example 1] <Fabrication of eyeglass lenses (photochromic products)> As the lens substrate, a plastic lens substrate 1 (product name PHOENIX, manufactured by HOYA Corporation; urea resin obtained by reaction of isocyanate-terminated prepolymer and aromatic diamine; refractive index 1.53, center wall thickness 8.3 mm, radius 75 mm, BC 4.00) was used. The lens substrate was treated with UV ozone for 60 seconds, then washed with pure water and dried. Afterward, a primer layer was formed on the convex surface (object-facing surface) of the plastic lens substrate. For details, see below. Structure below: [ka] A hydroxyl group-containing bifunctional acrylate (10 parts by mass) was mixed with Tosoh Corporation's Coronate 2715 (40 parts by mass) and 2-phenoxyethyl acrylate (viscosity: 13 cP) (50 parts by mass) as polyisocyanates. To the resulting mixture, a photoradical polymerization initiator (bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide (Omnirad819, IGM Resin BV)) was added in an amount of 0.02% by mass per 100% by mass of the total mixture and thoroughly stirred. Then, the mixture was degassed using a rotation-and-revolution type stirring and degassing apparatus. The resulting polymerizable composition for primer layer formation was applied to the convex surface of a plastic lens substrate by spin coating in an environment of 25°C and 50% relative humidity. The polymerizable composition for primer layer formation applied to the plastic lens substrate was then exposed to ultraviolet light (UV irradiance of 250 mW / cm² at a wavelength of 405 nm) in a nitrogen atmosphere (oxygen concentration of 500 ppm or less). 2 The composition was cured by irradiation with ) to form a primer layer. The thickness of the formed primer layer was 8 μm. A polymerizable composition for photochromic layer formation, prepared as described below, was applied to the primer layer by spin coating to form a coated layer. The object to be irradiated with this coated layer was placed in an ultraviolet irradiation device, and the atmosphere inside the device was changed to a nitrogen atmosphere (oxygen concentration of 500 ppm or less) by nitrogen purging. Then, ultraviolet light (wavelength 405 nm, ultraviolet irradiance of 250 mW / cm²) was directed towards the surface of the coated layer. 2 The coated layer was cured by irradiation with ) to form a photochromic layer. The thickness of the formed photochromic layer was 40 μm. A polymerizable composition for forming a protective layer, prepared as described below, was applied to the above-mentioned photochromic layer by spin coating to form a coated layer. The object to be irradiated with this coated layer was placed in an ultraviolet irradiation device, and the atmosphere inside the device was changed to a nitrogen atmosphere (oxygen concentration of 500 ppm or less) by nitrogen purging. Then, ultraviolet light (wavelength 405 nm, ultraviolet irradiance of 250 mW / cm²) was directed towards the surface of the coated layer. 2 The first UV irradiation was performed by irradiating the object with UV light for 2 seconds. After the first UV irradiation, the UV irradiation from the light source was temporarily stopped, and the atmosphere inside the device was replaced with an atmospheric atmosphere while the object to be irradiated remained inside the device. Then, UV irradiation from the light source was restarted, and UV light (wavelength 405 nm, UV irradiance 250 mW / cm²) was applied. 2 A second UV irradiation was performed by irradiating the object with UV light for 25 seconds. The time interval between the first and second UV irradiations was 60 minutes. As mentioned earlier, the object to be irradiated can also be removed from the UV irradiation device and visually inspected between the first and second UV irradiations. In this way, the coating layer of the polymerizable composition for forming the protective layer was cured to form a cured layer (protective layer). The thickness of the formed protective layer was 38 μm.

[0081] <Preparation of polymerizable composition for photochromic layer formation> In a plastic container, 90 parts by mass of polyethylene glycol dimethacrylate (in formula 1 above, n=14, R is an ethylene group, molecular weight 736), which is component A, and 10 parts by mass of tricyclodecanedimethanol dimethacrylate (molecular weight 332), which is component B, were mixed. The mixture of polymerizable compounds obtained in this way was mixed with a photochromic compound (an indeno-condensed naphthopyran compound represented by the structural formula described in U.S. Patent No. 5,645,767), a photoradical polymerization initiator (bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide (Omnirad 819, manufactured by IGM Resin BV)), an antioxidant (ethylenebis(oxyethylene)bis-(3-(5-tert-butyl-4-hydroxy-m-tolyl)propionate)), and a light stabilizer (a mixture of bis(1,2,2,6,6-pentamethyl-4-piperidinyl) sebacate and methyl(1,2,2,6,6-pentamethyl-4-piperidinyl) sebacate) and thoroughly stirred. Then, the mixture was degassed using a rotation-and-revolution type stirring and degassing apparatus. In this way, a polymerizable composition for photochromic layer formation was prepared. The content of the above components, relative to the total amount of the composition (100% by mass), is as follows: the mixture of polymerizable compounds is 90.0% by mass, the photochromic compound is 5.7% by mass, the photoradical polymerization initiator is 0.7% by mass, the antioxidant is 2.7% by mass, and the photostabilizer is 0.9% by mass.

[0082] <Preparation of polymerizable composition for forming a protective layer> In a plastic container, 99.0 parts by mass of tricyclodecanedimethanol diacrylate (a cyclic bifunctional (meth)acrylate) and 1.0 part by mass of bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide (Omnirad819, manufactured by IGM Resin BV) were mixed and thoroughly stirred, and then degassed using a rotation-and-revolution type stirring and degassing apparatus. In this way, a polymerizable composition for forming a protective layer was prepared. In the polymerizable composition for forming the protective layer described above, the (meth)acrylate is only alicyclic bifunctional (meth)acrylate; therefore, the content of alicyclic bifunctional (meth)acrylate is 100% by mass relative to the total amount of (meth)acrylate.

[0083] [Comparative Example 1] Eyeglass lenses were manufactured in the same manner as in Example 1, except that the curing treatment of the coating layer of the polymerizable composition for forming the protective layer was performed by a single stage of ultraviolet irradiation. In Comparative Example 1, the ultraviolet irradiation was performed under the same conditions as the first ultraviolet irradiation in Example 1, except that the ultraviolet irradiation time was changed to 15 seconds.

[0084] [Example 2] An eyeglass lens was manufactured using the same method as in Example 1, except that the lens substrate was changed to plastic lens substrate 2 (Tegra, a polycarbonate resin manufactured by VISION EASE; refractive index 1.59, center thickness 8.8 mm, radius 75 mm, BC 4.00).

[0085] [Comparative Example 2] Eyeglass lenses were fabricated in the same manner as in Example 2, except that the light irradiation for protective layer formation was carried out in the same manner as in Comparative Example 1.

[0086] [Example 3] Eyeglass lenses were fabricated using the same method as in Example 1, except that the time interval between the first and second UV irradiations was changed to 30 minutes.

[0087] [Example 4] Except for changing the irradiation time of the second UV irradiation to 13 seconds, eyeglass lenses were manufactured using the same method as in Example 1.

[0088] [Example 5] The number of UV irradiation sessions was changed to three, with a 30-minute interval between each irradiation. The first UV irradiation was performed under the same conditions as in Example 1 (irradiation time 2 seconds), the second UV irradiation was performed with a changed irradiation time of 13 seconds, and the third UV irradiation was performed with UV light (wavelength 405 nm, UV irradiance 250 mW / cm²). 2 This was carried out by irradiating with ) for 12 seconds. Except for the points mentioned above, eyeglass lenses were manufactured in the same manner as in Example 1.

[0089] [Comparative Example 3] Eyeglass lenses were manufactured using the same method as in Comparative Example 1, except that the irradiation time for UV light to form the protective layer was changed to 27 seconds.

[0090] The eyeglass lenses prepared as described above were evaluated for lightfastness using the following method. In the examples and comparative examples shown in Table 3, three eyeglass lenses were prepared for each case. One lens was used for lightfastness evaluation, another for hardness evaluation, and the remaining lens for adhesion evaluation.

[0091] [Evaluation Method] <Evaluation of lightfastness> (Accelerated testing) A xenon weather meter (model: X25A) manufactured by Suga Test Instruments Co., Ltd. was used as the accelerated testing apparatus. An eyeglass lens was placed inside the accelerated testing apparatus with its surface facing upwards, and the lens was exposed to light irradiation for 100 hours. The ambient temperature inside the apparatus was 63°C, the relative humidity was 10%, and the illuminance during light irradiation was 320 W / m². 2 That's what I decided.

[0092] (ΔT (at the time of color development)) The color density of the spectacle lenses prior to the accelerated testing described above was evaluated using the following method in accordance with JIS T7333:2005. The object-side surface of the spectacle lens was irradiated with light from a xenon lamp through an aeromass filter for 15 minutes (900 seconds) to induce color development of the photochromic compound in the photochromic layer. The transmittance T (unit: %, measurement wavelength: 550 nm) at the time of color development was measured using a spectrophotometer manufactured by Otsuka Electronics Industry Co., Ltd. The above light irradiation was carried out so that the irradiance and tolerance of irradiance were the values ​​shown in Table 1 below, as specified in JIS T7333:2018.

[0093] [Table 1]

[0094] For the eyeglass lenses after the accelerated light exposure test described above, the transmittance at the time of color development was determined in the same manner as above. ΔT was calculated as ΔT = (T after accelerated irradiation) - (T before accelerated light exposure test). The calculated values ​​are shown in Table 2. A smaller ΔT value indicates superior lightfastness.

[0095] (ΔYI) The YI value of the spectacle lenses prior to the accelerated testing described above was measured using a DOT-3 spectral transmittance meter manufactured by Murakami Color Technology Laboratory, as specified in JIS K7373:2006. The YI value is an indicator of the degree of tinting; a smaller value indicates less tinting. The YI value was calculated for the eyeglass lenses after the accelerated irradiation test described above, in the same manner as above. ΔYI = (YI value after accelerated irradiation) - (YI value before accelerated irradiation) was calculated. The calculated values ​​are shown in Table 2. A smaller ΔYI value indicates superior lightfastness.

[0096] <Evaluation of adhesion (cross-cut method)> For the examples and comparative examples shown in Table 3, the adhesion of the spectacle lenses after immersion in 100°C hot water for 1 hour was evaluated using the cross-cut method in accordance with JIS K5600-5-6:1999. The evaluation results are shown in Table 3.

[0097] <Hardness evaluation> For the examples and comparative examples shown in Table 3, the Vickers hardness HV of the protective layer of the spectacle lenses was determined using a Mitutoyo micro-Vickers hardness tester in accordance with JIS Z2244:2009. The evaluation results are shown in Table 3.

[0098] [Table 2]

[0099] [Table 3]

[0100] The results shown in Table 2 confirm that in Examples 1, 3-5, performing the curing treatment for protective layer formation by multi-stage light irradiation improved the light resistance of the photochromic article (eyeglass lens) compared to the case where it was performed by single-stage light irradiation (Comparative Example 1). The same can be confirmed from the comparison between Example 2 and Comparative Example 2 shown in Table 2. Furthermore, the results shown in Table 2 and Table 3 confirm that performing the curing treatment by multi-stage light irradiation makes it possible to improve the light resistance of the photochromic article (eyeglass lens) without affecting adhesion or hardness.

[0101] [Example 6] A hard coat layer was formed on the protective layer of the eyeglass lens of Example 1 by the following method, and an eyeglass lens of Example 3 having a hard coat layer was fabricated. In a glass container equipped with a magnetic stirrer, 17 parts by mass of γ-glycidoxypropyltrimethoxysilane, 30 parts by mass of methanol, and 28 parts by mass of water-dispersed colloidal silica (solids content 40% by mass, average particle size 15 nm) were added and thoroughly mixed, and stirred at 5°C for 24 hours. Next, 15 parts by mass of propylene glycol monomethyl ether, 0.05 parts by mass of a silica-based surfactant, and 1.5 parts by mass of aluminum acetylacetonate as a curing agent were added, and after thorough stirring, the mixture was filtered to prepare a hard coating solution (polymerizable composition for hard coat layer formation). After wiping the surface of the protective layer of each spectacle lens prepared as described above with acetone, the hard coating solution was applied using the dip-coating method (pulling speed 20 cm / min). Subsequently, a 3 μm thick hard coat layer (organosilicon-based hardened layer) was formed by heating and curing in a heat treatment furnace at a temperature of 100°C for 60 minutes.

[0102] Finally, we will summarize each of the aforementioned aspects.

[0103] According to one embodiment, a method for manufacturing a photochromic article is provided. The photochromic article comprises, in this order, a substrate, a photochromic layer containing a photochromic compound, and a protective layer which is a cured layer of a polymerizable composition. The manufacturing method includes forming a coating layer of a polymerizable composition on the photochromic layer and curing the coating layer, wherein the curing treatment is a multi-stage light irradiation.

[0104] According to the above manufacturing method, photochromic articles with excellent light resistance can be produced.

[0105] In one embodiment, the multi-stage light irradiation described above can be a two-stage light irradiation.

[0106] In one embodiment, the polymerizable composition may contain (meth)acrylate.

[0107] In one embodiment, the photochromic layer may be a cured layer of a polymerizable composition containing a photochromic compound.

[0108] In one embodiment, the polymerizable composition containing the above-mentioned photochromic compound may contain (meth)acrylate.

[0109] In one embodiment, the above-mentioned photochromic article can be an eyeglass lens.

[0110] In one embodiment, the above-mentioned photochromic article can be a lens for goggles.

[0111] In one embodiment, the photochromic article can be the visor portion of a sun visor.

[0112] In one embodiment, the photochromic article can be a shield component of a helmet.

[0113] The various embodiments and forms described herein can be combined in any combination of two or more.

[0114] The embodiments disclosed herein should be considered in all respects to be illustrative and not restrictive. The scope of the present invention is indicated by the claims rather than by the foregoing description, and all modifications within the meaning and scope equivalent to the claims are intended to be included. [Industrial applicability]

[0115] This invention is useful in the technical fields of eyeglasses, goggles, sun visors, helmets, and the like.

Claims

1. A method for manufacturing a photochromic article, The aforementioned photochromic article is a photochromic article having, in this order, a substrate, a photochromic layer containing a photochromic compound, a protective layer which is a cured layer of a polymerizable composition, and an organosilicon-based cured layer. Forming a coating layer of the polymerizable composition on the photochromic layer, and The aforementioned coating layer is subjected to a curing treatment. This includes forming a protective layer, and The method for manufacturing a photochromic article, wherein the curing treatment is a multi-stage light irradiation.

2. The method for manufacturing a photochromic article according to claim 1, wherein the multi-stage light irradiation is a two-stage light irradiation.

3. The method for producing a photochromic article according to claim 1 or 2, wherein the polymerizable composition comprises (meth)acrylate.

4. The method for producing a photochromic article according to any one of claims 1 to 3, wherein the polymerizable composition comprises an alicyclic bifunctional (meth)acrylate.

5. The method for producing a photochromic article according to Claim 4, wherein the polymerizable composition contains 70.0% by mass or more of alicyclic bifunctional (meth)acrylate, with the total amount of (meth)acrylate contained in the polymerizable composition being 100% by mass.

6. A method for producing a photochromic article according to any one of claims 1 to 5, wherein the photochromic layer is a cured layer of a polymerizable composition containing a photochromic compound.

7. The polymerizable composition containing the photochromic compound comprises (meth)acrylate, the method for producing a photochromic article according to claim 6.

8. The method for manufacturing a photochromic article according to any one of claims 1 to 7, wherein the photochromic article is an eyeglass lens.

9. The method for manufacturing a photochromic article according to any one of claims 1 to 7, wherein the photochromic article is a lens for goggles.

10. The method for manufacturing a photochromic article according to any one of claims 1 to 7, wherein the photochromic article is the visor portion of a sun visor.

11. The method for manufacturing a photochromic article according to any one of claims 1 to 7, wherein the photochromic article is a shield member for a helmet.

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