Production method for finished lens

Abstract

According to the present invention, a production method for a finished lens includes an application step for applying a photocurable composition to one surface of a lens base material, a spraying step for spraying an inert gas toward the other surface of the lens base material, and a curing step for curing the photocurable composition by photoirradiation.

Description

Finished lens manufacturing method

[0001] The present disclosure relates to a method for manufacturing a finished lens, and more particularly to a method for manufacturing a finished lens that is easy to work with, has excellent productivity, and is capable of manufacturing a finished lens that has little thermal deformation.

[0002] In the fields of eyeglass lenses, goggle lenses, and the like, lenses having one or more properties may be used, such as photochromic properties, anti-reflection properties, anti-fouling properties, and scratch resistance.

[0003] A method for imparting the above properties to a lens includes applying a photocurable composition (e.g., a polymerizable composition for forming a photochromic layer containing a photochromic compound and a polymerizable compound) that exhibits one or more of the above properties to the surface of a lens substrate, and then irradiating the applied photocurable composition with light to cure it, thereby forming a cured coating layer having the above properties. This method can be repeated multiple times to produce lenses with multiple cured coating layers, i.e., lenses with multiple properties. However, curing the photocurable composition may require a large amount of light irradiation, and the heat generated by the irradiated light may significantly deform the lens, making it unsuitable for use. Therefore, a method for producing lenses (including finished lenses having one or more properties) that exhibit minimal deformation is desired.

[0004] Patent Document 1 discloses a method for suppressing thermal deformation of a lens substrate by keeping the surface temperature of the lens substrate at 100°C or less when photocuring a photocurable composition applied to the surface of the lens substrate.

[0005] Japanese Patent Application Laid-Open No. 2004-012857

[0006] However, the method described in Patent Document 1 controls the light intensity and irradiation time on the surface of the lens substrate, and therefore requires intermittent and long-term light irradiation, posing problems in terms of ease of operation and productivity. Furthermore, while it was possible to shorten the light irradiation time to some extent by combining it with a method of cooling the lens substrate by contacting the back surface or even the side surface of the lens substrate with a tube through which cold water is circulated, this method also had problems such as a complex device structure and uneven cooling effects occurring between the contact and non-contact areas of the tube and the lens substrate.

[0007] An object of one aspect of the present disclosure is to provide a method for manufacturing a finished lens that is easy to work with, has excellent productivity, and is capable of manufacturing a finished lens that is less susceptible to thermal deformation.

[0008] Embodiments of the present disclosure relate to the following [1] to [8]. [1] A method for producing a finished lens, comprising: a coating step of coating one surface of a lens substrate with a photocurable composition; a spraying step of spraying an inert gas toward the other surface of the lens substrate; and a curing step of curing the photocurable composition by light irradiation. [2] The method for producing a finished lens according to [1] above, wherein the spraying step is carried out in a furnace in which the curing step is carried out, and the spray rate of the inert gas is 0.5 to 4.0 times / minute relative to the volume of the furnace. [3] The method for producing a finished lens according to [1] or [2] above, wherein the spray rate of the inert gas is 0.8 to 7.0 L / minute. [4] The method for producing a finished lens according to any of [1] to [3] above, wherein the one surface is convex and the other surface is concave. [5] The method for producing a finished lens according to any of [1] to [4] above, wherein the inert gas is at least one gas selected from the group consisting of nitrogen gas, argon gas, and carbon dioxide gas. [6] The method for producing a finished lens according to any one of [1] to [5] above, wherein the photocurable composition is at least one selected from the group consisting of a polymerizable composition for forming a primer layer, a polymerizable composition for forming a photochromic layer, and a polymerizable composition for forming a protective layer. [7] The method for producing a finished lens according to any one of [1] to [6] above, wherein the lens substrate has a thickness of less than 2 mm in a central portion and a peripheral portion that is thicker than the central portion. [8] The method for producing a finished lens according to [7] above, wherein an inert gas is injected into the central portion.

[0009] As a result of intensive research into solving the above problems, the inventors discovered that the above problems could be solved by spraying an inert gas toward the other surface of the lens substrate that is not coated with a photocurable composition when irradiating light onto a photocurable composition coated on one surface of the lens substrate, and thus completed the present invention. Note that the detailed mechanism by which thermal deformation of the finished lens is suppressed by the above method is unknown, but it is speculated that this is because the spraying of the inert gas disperses heat that has accumulated on the surface of the lens substrate, making it easier for heat within the lens substrate to be dissipated from the surface of the lens substrate.

[0010] According to one aspect of the present disclosure, it is possible to provide a method for manufacturing a finished lens that is easy to work with, has excellent productivity, and is capable of manufacturing a finished lens that is less subject to thermal deformation.

[0011] 1 is a schematic diagram illustrating Example 1. FIG. 2 is a schematic diagram illustrating Comparative Example 1. FIG. 3 is a schematic diagram illustrating Comparative Examples 2 and 3.

[0012] The following description is based on an example of an embodiment of the present disclosure. However, the embodiments described below are merely examples for embodying the technical concept of the present disclosure, and the present disclosure is not limited to the following description. The present disclosure also includes any embodiment or combination of any of the features described herein. In the present disclosure and this specification, preferred specifications can be selected arbitrarily, and combinations of preferred specifications are considered more preferable. In the present disclosure and this specification, the expression "XX to YY" means "XX or more and YY or less." In the present disclosure and this specification, for preferred numerical ranges (e.g., ranges of content, etc.), lower and upper limits described in stages can be independently combined. For example, the expression "preferably 10 to 90, more preferably 30 to 60" can be combined with the "preferable lower limit (10)" and the "more preferable upper limit (60)" to form "10 to 60." Furthermore, in the numerical ranges described in the present disclosure and this specification, the upper or lower limit of the numerical range may be replaced with a value shown in the examples. In the present disclosure and this specification, a polymerizable composition refers to a composition containing a polymerizable compound. Furthermore, a polymerizable compound refers to a compound having a polymerizable group. In this disclosure and this specification, a "cured coating layer" refers to a cured polymerizable composition. For example, a cured coating layer obtained by curing a polymerizable composition for forming a primer layer is referred to as a primer layer, a cured coating layer obtained by curing a polymerizable composition for forming a photochromic layer is referred to as a photochromic layer, a cured coating layer obtained by curing a polymerizable composition for forming a protective layer is referred to as a protective layer, and a cured coating layer obtained by curing a polymerizable composition for forming a hardcoat layer is referred to as a hardcoat layer. In this disclosure and this specification, "on the surface of X" refers not only to "on the surface of X (contact state)" but also to "above the surface of X (non-contact state)." In this disclosure and this specification, "(meth)acrylate" refers to both acrylate and methacrylate. "Acrylate" refers to a compound having one or more acryloyl groups in one molecule. "Methacrylate" refers to a compound having one or more methacryloyl groups in one molecule.For (meth)acrylates, the functionality is the number of groups selected from the group consisting of acryloyl groups and methacryloyl groups contained in one molecule. Furthermore, "methacrylate" refers to a compound containing only methacryloyl groups as (meth)acryloyl groups, while a compound containing both acryloyl and methacryloyl groups as (meth)acryloyl groups is referred to as a (meth)acrylate. The acryloyl group may be contained in the form of an acryloyloxy group, and the methacryloyl group may be contained in the form of a methacryloyloxy group. In this disclosure and this specification, the term "(meth)acryloyl group" is used to encompass both acryloyl groups and methacryloyl groups, and the term "(meth)acryloyloxy group" encompasses both acryloyloxy groups and methacryloyloxy groups. In this disclosure and this specification, unless otherwise specified, the groups described may be substituted or unsubstituted. When a group has a substituent, examples of the substituent include an alkyl group (e.g., a linear alkyl group having 1 to 6 carbon atoms or a branched alkyl group having 1 to 6 carbon atoms), a hydroxyl group, an alkoxy group (e.g., an alkoxy group having 1 to 6 carbon atoms), a halogen atom (e.g., a fluorine atom, a chlorine atom, or a bromine atom), a cyano group, an amino group, a nitro group, an acyl group, a carboxy group, an aryl group, and a polyether group. Furthermore, the "carbon number" of a substituted group refers to the number of carbon atoms in the portion excluding the substituent. In this disclosure and this specification, "linear alkyl group or branched alkyl group" does not include a cycloalkyl group. A linear alkyl group or branched alkyl group may be unsubstituted or may have a substituent. It is acceptable for a linear alkyl group or branched alkyl group to have a cycloalkyl group (e.g., a cyclohexyl group) as a substituent. In one embodiment, the linear alkyl group or branched alkyl group preferably does not have a cycloalkyl group as a substituent. In this disclosure and this specification, "viscosity" refers to a value measured using a vibration viscometer in an atmospheric atmosphere at a temperature of 25°C. In this disclosure and this specification, "total amount" refers to the total amount of all components excluding the solvent, if the solvent is included. In this disclosure and this specification, "central portion of the lens substrate" refers to the portion within a radius of 5 mm from the center of the lens substrate.In this disclosure and this specification, the term "peripheral portion of the lens substrate" refers to the outermost portion of the lens substrate (a portion with a radius of 15 mm or more from the center of the lens substrate). In this disclosure and this specification, the term "finished lens" refers to a semi-finished lens that has been processed by polishing or grinding into a lens for actual use, or a lens molded into a lens for actual use. In this disclosure and this specification, the term "lens substrate thickness" refers to the value measured using a high-performance ABS Digimatic Indicator (ID-FNX series, manufactured by Mitutoyo Corporation) with terminals connected to the convex and concave surfaces of the lens substrate. In this disclosure and this specification, the term "cured coating layer thickness" refers to the value calculated from the film thickness analysis using FFT (fast Fourier transform) after measuring the reflectance (interference waveform) of a sample using a non-contact film thickness measuring instrument (FF8 series, manufactured by System Road Corporation). In this disclosure and this specification, the term "solid content" refers to non-volatile content excluding volatile substances such as solvents, and includes liquid, starch syrup-like, and wax-like substances at room temperature. The total solid content can also be calculated from the charge amount. "Room temperature" in this disclosure and this specification refers to the ambient temperature without temperature control such as heating or cooling, and is generally around 20°C, but is not limited to the above range as this may vary depending on the weather and season. "Light irradiation intensity" in this disclosure and this specification refers to a value measured using an actinometer (UIT-250, manufactured by USHIO Corporation) by lighting a lens base 300 mm away from the center of the light source to the light receiving unit (center wavelength 365 mm). "Light irradiation exposure amount" in this disclosure and this specification refers to the integrated value of irradiation time (light irradiation intensity (mW / cm)) measured using an actinometer (UIT-250, manufactured by USHIO Corporation) by lighting a lens base 300 mm away from the center of the light source to the light receiving unit (center wavelength 365 mm). ２ ) × irradiation time (seconds).

[0013] [Method for manufacturing a finished lens] Hereinafter, a method for manufacturing a finished lens according to one embodiment of the present disclosure is not particularly limited as long as it includes a coating step of coating one surface of a lens substrate with a photocurable composition, a spraying step of spraying an inert gas toward the other surface of the lens substrate, and a curing step of curing the photocurable composition by light irradiation, and may further include other steps as necessary. Each step will be described in more detail below.

[0014] <Coating Step> The coating step in the method for producing a finished lens according to one embodiment of the present disclosure is a step of coating one surface of a lens substrate with a photocurable composition, and may or may not include other treatments. The coating step is a step performed before the spraying step, and may or may not be performed in the same furnace as the spraying step described below.

[0015] The method for applying the photocurable composition is not particularly limited, and examples thereof include known application methods such as spin coating, spray coating, dip coating, and dip-spin coating. These may be used alone or in combination of two or more. Among these, spin coating is preferred from the viewpoint of uniformity of application.

[0016] The rotation speed in spin coating is not particularly limited, and is preferably 1 to 6000 rpm, more preferably 10 to 5000 rpm, and particularly preferably 50 to 4000 rpm. When the rotation speed is equal to or higher than the lower limit of the above range, coating becomes easier, and when the rotation speed is equal to or lower than the upper limit of the above range, thin film formation becomes easier.

[0017] The coating step may or may not include other treatments as necessary in addition to coating one surface of the lens substrate with the photocurable composition. There are no particular limitations on the type of other treatments in the coating step, and examples include pretreatments carried out prior to coating the photocurable composition. Pretreatments are preferably carried out from the viewpoint of improving adhesion between the cured coating layer of the photocurable composition and the lens substrate.

[0018] One form of the pretreatment is not particularly limited, and examples thereof include chemical treatment with a basic aqueous solution or an acidic aqueous solution, polishing treatment using an abrasive, plasma treatment using atmospheric pressure plasma or low pressure plasma, corona discharge treatment, UV ozone treatment, etc. These may be used alone or in combination of two or more.

[0019] (Lens Substrate) The lens substrate will now be described in more detail.

[0020] In the present disclosure and this specification, the material for the lens substrate is not particularly limited and includes, for example, (meth)acrylic resins; styrene 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 reacting an isocyanate compound with a hydroxy compound such as diethylene glycol; thiourethane resins obtained by reacting an isocyanate compound with a polythiol compound; cured products (generally referred to as transparent resins) obtained by curing a curable composition containing a (thio)epoxy compound having one or more disulfide bonds in the molecule; oxides such as boric oxide, aluminum oxide, and silicon oxide; and the like. These may be used alone or in combination of two or more.

[0021] The type of the lens substrate is not particularly limited, and examples thereof include lens substrates used in spectacles and lens substrates used in goggles.

[0022] The color of the lens substrate is not particularly limited, and it may be colorless (an undyed lens) or dyed.

[0023] The refractive index of the lens substrate is not particularly limited and may be, for example, 1.50 to 1.75. Note that in this disclosure and this specification, the refractive index refers to the refractive index for light of mercury e-line at 546.07 nm.

[0024] The focal point of the lens substrate is not particularly limited, and examples thereof include single-focus, multi-focus, and progressive-addition lenses.

[0025] The surface of the lens substrate is not particularly limited, and examples thereof include a convex surface, a concave surface, a flat surface, etc. In a typical lens substrate, the object-side surface is a convex surface and the eyeball-side surface is a concave surface, but the present disclosure is not limited to this.

[0026] The thickness of the central portion of the lens substrate is not particularly limited, but from the viewpoint of optical design, it is preferably less than 9.1 mm, more preferably 0.8 to 2.4 mm, and particularly preferably 0.8 mm or more and less than 2.0 mm. The thickness of the peripheral portion of the lens substrate is not particularly limited, but from the viewpoint of optical design, it is preferably thicker than the central portion, more preferably 0.8 to 16.5 mm, and particularly preferably 1.6 to 13.0 mm.

[0027] There are no particular limitations on the one surface of the lens substrate, and examples thereof include a convex surface, a concave surface, a flat surface, etc. There are no particular limitations on the other surface of the lens substrate, and examples thereof include a convex surface, a concave surface, a flat surface, etc. In one embodiment, the one surface of the lens substrate onto which the photocurable composition is applied can be a convex surface, and the other surface of the lens substrate onto which the inert gas is sprayed can be a concave surface.

[0028] (Photocurable Composition) The photocurable composition will be described in more detail below.

[0029] In this disclosure and this specification, a photocurable composition is a polymerizable composition that has the property of being cured by irradiation with light, and is a composition that, after curing, exhibits one or more properties such as photochromic properties, antireflection properties, antifouling properties, scratch resistance, etc. By forming one or more cured coating layers, which are cured products of the photocurable compositions, on the surface of a lens substrate, the finished lens can acquire properties such as photochromic properties, antireflection properties, antifouling properties, scratch resistance, etc.

[0030] The photocurable composition is not particularly limited, and examples thereof include a polymerizable composition for forming a primer layer, a polymerizable composition for forming a photochromic layer, a polymerizable composition for forming a protective layer, and a polymerizable composition for forming a hard coat layer. These may be used alone or in combination of two or more. The polymerizable composition for forming a primer layer, the polymerizable composition for forming a photochromic layer, and the polymerizable composition for forming a protective layer will be described in more detail below.

[0031] ((Polymerizable composition for forming primer layer)) One form of the polymerizable composition for forming a primer layer (hereinafter sometimes simply referred to as "primer layer composition") is, for example, a primer layer composition containing a polyisocyanate, a hydroxy group-containing polymerizable compound, and at least one polymerizable compound selected from the group consisting of (meth)acrylates and vinyl ethers, having a viscosity of 100 cP or less. There are no particular restrictions on the components contained in the primer layer composition, but it is preferable that the composition contain the above three components from the viewpoint of suppressing attenuation of photochromic properties caused by the primer layer, which is a cured product of the primer layer composition, and from the viewpoint of adhesion between the primer layer and other cured coating layers. The various components contained in the primer layer composition will be described in more detail below.

[0032] -Polyisocyanate- The polyisocyanate is a compound having two or more isocyanate groups per molecule. The number of isocyanate groups contained in one molecule of the polyisocyanate is not particularly limited, but is preferably 2 to 6, more preferably 3 to 5, and particularly preferably 3 to 4. When the number is equal to or greater than the lower limit of the above range, the water resistance of the primer layer is likely to be improved, and when the number is equal to or less than the upper limit of the above range, adhesion to the lens substrate is likely to be improved.

[0033] There are no particular restrictions on the molecular weight of the polyisocyanate, but it is preferably 200 to 800, more preferably 300 to 700, and particularly preferably 400 to 600. If it is at least the lower limit of the above range, adhesion to the lens substrate will be facilitated, and if it is at most the upper limit of the above range, the water resistance of the primer layer will be likely to be improved.

[0034] Specific examples of the polyisocyanate are not particularly limited, and include aromatic diisocyanates such as xylylene diisocyanate, phenylene diisocyanate, tolylene diisocyanate, diphenylmethane diisocyanate, and naphthalene diisocyanate; and aliphatic or alicyclic diisocyanates such as hexamethylene diisocyanate, lysine diisocyanate, cyclohexane diisocyanate, isophorone diisocyanate, 4,4'-dicyclohexylmethane diisocyanate, 1,3-bisisocyanatomethylcyclohexane, and tetramethylxylylene diisocyanate. These may be used alone or in combination of two or more. The polyisocyanates exemplified above may be in the form of an allophanate, adduct, biuret, or isocyanurate. These may be used alone or in combination of two or more. Furthermore, commercially available polyisocyanates are not particularly limited, and examples thereof include those manufactured by Tosoh Corporation such as Coronate HX, Coronate HXR, Coronate HXLV, Coronate HK, Coronate 2715, Coronate HL, Coronate L, Coronate 2037, HDI, TDI, and MDI; and those manufactured by Mitsui Chemicals, Inc. such as 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. These may be used alone or in combination of two or more.

[0035] -Hydroxy Group-Containing Polymerizable Compound- The number of hydroxy groups contained in one molecule of the hydroxy group-containing polymerizable compound is not particularly limited, but is preferably 1 to 6, more preferably 1 to 5, and particularly preferably 2 to 4. When the number is equal to or greater than the lower limit of the above range, the reaction efficiency with the polyisocyanate tends to be good, and when the number is equal to or less than the upper limit of the above range, adhesion to the photochromic layer tends to be good. The present inventors speculate that the urethane bond formed by reacting the isocyanate group of the polyisocyanate with the hydroxy group of the hydroxy group-containing polymerizable compound contributes to improved adhesion of the primer layer.

[0036] The number of polymerizable groups contained in one molecule of the hydroxy group-containing polymerizable compound is not particularly limited, but is preferably 2 or more from the viewpoint of the efficiency of the polymerization reaction.

[0037] One embodiment of the hydroxy group-containing polymerizable compound is a (meth)acrylate. When the hydroxy group-containing polymerizable compound is a (meth)acrylate, the number of functional groups of the (meth)acrylate is not particularly limited, but from the viewpoint of adhesion, it is preferably 1 (monofunctional) to 3, more preferably 2 to 3. The (meth)acryloyl group, which is the functional group, may contain only an acryloyl group, may contain only a methacryloyl group, or may contain an acryloyl group and a methacryloyl group. In one embodiment, from the viewpoint of adhesion, it is preferable that the hydroxy group-containing polymerizable compound contains only an acryloyl group as the (meth)acryloyl group.

[0038] The molecular weight of the hydroxy group-containing polymerizable compound is not particularly limited, but is preferably 100 to 600, more preferably 200 to 500, and particularly preferably 300 to 400. When the molecular weight is equal to or greater than the lower limit of the above range, the reaction efficiency with the polyisocyanate tends to be good, and when the molecular weight is equal to or less than the upper limit of the above range, adhesion to the photochromic layer tends to be good.

[0039] Specific examples of the (meth)acrylate are not particularly limited and include, for example, 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, 2-(acryloxyoxy)ethyl 2-hydroxyethyl phthalate, and compounds represented by the following formula (1): These may be used alone or in combination of two or more.

[0040] ...(1)

[0041] One example of the hydroxy group-containing polymerizable compound is a hydroxy group-containing polymerizable compound having an amide group. The hydroxy group-containing polymerizable compound having an amide group is not particularly limited, and examples thereof include N-(2-hydroxyethyl)acrylamide.

[0042] One example of the hydroxyl group-containing polymerizable compound is a hydroxyl group-containing polymerizable compound having an epoxy ester structure. The epoxy ester structure is a structure formed by the reaction of an epoxy group with a carboxyl group, and is represented by the formula "-CH(OH)-CH ２ -O-C(=O)-". Commercially available hydroxy group-containing polymerizable compounds having an epoxy ester structure are not particularly limited, and examples 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.), and Epoxy Ester 3000A (manufactured by Kyoeisha Chemical Co., Ltd.). These may be used alone or in combination of two or more types.

[0043] -Polymerizable Compound, Being At Least One Type Selected from the Group Consisting of (Meth)acrylates and Vinyl Ethers, Having a Viscosity of 100 cP or Less-The primer layer composition preferably contains at least one polymerizable compound, being selected from the group consisting of (meth)acrylates and vinyl ethers, having a viscosity of 100 cP (centipoise) or less (hereinafter, sometimes simply referred to as a "low-viscosity polymerizable compound.") The present inventors speculate that a primer layer composition containing the low-viscosity polymerizable compound suppresses attenuation of photochromic properties caused by the primer layer.

[0044] The viscosity of the low-viscosity polymerizable compound is not particularly limited as long as it is 100 cP or less. From the viewpoint of ease of handling and suppression of the occurrence of optical defects, the viscosity is preferably 5 to 70 cP, more preferably 10 to 50 cP.

[0045] The number of functional groups in the (meth)acrylate, which is one form of the low-viscosity polymerizable compound, is not particularly limited, but from the viewpoint of adhesion, it is preferably 1 (monofunctional) to 3, more preferably 1 (monofunctional) to 2. The (meth)acrylate, which is one form of the low-viscosity polymerizable compound, may contain an aryl group (e.g., a phenyl group), an amide group, or the like. In the present disclosure and this specification, a "vinyl ether" refers to a compound having one or more vinyl groups and one or more ether bonds in one molecule, preferably two or more vinyl groups in one molecule, and more preferably two to four vinyl groups in one molecule. Furthermore, the number of ether bonds contained in the vinyl ether is preferably two to four in one molecule.

[0046] The molecular weight of the low-viscosity polymerizable compound is not particularly limited, but is preferably 100 to 300, and more preferably 150 to 250. When the molecular weight is equal to or greater than the lower limit of the above range, the occurrence of optical defects is easily suppressed, and when the molecular weight is equal to or less than the upper limit of the above range, adhesion to the photochromic layer is easily achieved.

[0047] Specific examples of the low viscosity polymerizable compound are not particularly limited, and include, for example, 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, tridecyl (meth)acrylate, diethylene glycol butyl ether (meth)acrylate, cyclohexyl (meth)acrylate, tetrahydrofurfuryl (meth)acrylate, benzyl (meth)acrylate 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 Examples of such vinyl ethers include hexanediol di(meth)acrylate, hexanediol di(meth)acrylate, nonamethylene glycol di(meth)acrylate, isoamyl (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, and 2-(2-ethenoxyethoxy)ethyl 2-methylprop-2-enoate. These may be used alone or in combination of two or more.

[0048] The content of the low-viscosity polymerizable compound is not particularly limited, but is preferably 30.0 to 90.0 mass%, more preferably 35.0 to 80.0 mass%, and particularly preferably 40.0 to 70.0 mass%, based on 100 mass% of the total of the low-viscosity polymerizable compound, polyisocyanate, and hydroxy group-containing polymerizable compound. When the content is equal to or greater than the lower limit of the above range, handling becomes easier, while when the content is equal to or less than the upper limit of the above range, adhesion to the lens substrate becomes easier. In one embodiment of the content of the low-viscosity polymerizable compound, the compound is the component contained in the largest amount in a primer layer composition containing the low-viscosity polymerizable compound, polyisocyanate, and hydroxy group-containing polymerizable compound.

[0049] The content of the polyisocyanate is not particularly limited, but is preferably 10.0 to 70.0% by mass, more preferably 20.0 to 60.0% by mass, and particularly preferably 30.0 to 50.0% by mass, relative to 100% by mass of the total of the low-viscosity polymerizable compound, polyisocyanate, and hydroxy group-containing polymerizable compound. If the content is at least the lower limit of the above range, the water resistance of the primer layer is likely to be improved, while if it is at most the upper limit of the above range, adhesion to the lens substrate is likely to be improved.

[0050] The content of the hydroxy group-containing polymerizable compound is not particularly limited, but is preferably 3.0 to 30.0 mass%, more preferably 5.0 to 25.0 mass%, and particularly preferably 7.0 to 20.0 mass%, relative to 100 mass% of the total of the low-viscosity polymerizable compound, polyisocyanate, and hydroxy group-containing polymerizable compound. When the content is equal to or greater than the lower limit of the above range, the reaction efficiency with the polyisocyanate tends to be good, while when the content is equal to or less than the upper limit of the above range, adhesion to the photochromic layer tends to be good.

[0051] The primer layer composition may further contain a polymerization initiator, if necessary. The amount of the polymerization initiator to be added is not particularly limited, and from the viewpoint of primer layer formation efficiency, it is preferably 0.01 to 3.0 parts by mass per 100 parts by mass of the total of the low-viscosity polymerizable compound, polyisocyanate, and hydroxy group-containing polymerizable compound.

[0052] The polymerization initiator is not particularly limited, and known polymerization initiators can be used. The known polymerization initiator is not particularly limited, and examples thereof include photoradical polymerization initiators and thermal polymerization initiators. These may be used alone or in combination of two or more. Among these, photoradical polymerization initiators are preferred from the viewpoint of progressing the polymerization reaction in a short time. Specific examples of photoradical polymerization initiators can be found in the polymerization initiators that can be contained in the polymerizable composition for forming a photochromic layer described below.

[0053] The primer layer composition may or may not contain a solvent. When the primer layer composition contains a solvent, the solvent that can be used is not particularly limited as long as it does not inhibit the progress of the polymerization reaction of the polymerizable composition, and any solvent can be used. When the primer layer composition contains a solvent, the amount of the solvent is not particularly limited, but from the viewpoint of suppressing the occurrence of optical defects, it is preferably 10.0 parts by mass or less, more preferably 5.0 parts by mass or less, and particularly preferably 3.0 parts by mass or less, relative to 100 parts by mass of the total of the low-viscosity polymerizable compound, polyisocyanate, and hydroxy group-containing polymerizable compound.

[0054] The primer layer composition may further contain, as necessary, known additives that are typically added to compositions for forming a primer layer. The amount of the known additives to be added is not particularly limited as long as the effect of the primer layer is exhibited, and is preferably 1.0 to 20.0 parts by mass, more preferably 1.5 to 10.0 parts by mass, and particularly preferably 2.0 to 5.0 parts by mass, per 100 parts by mass of the total of the low-viscosity polymerizable compound, polyisocyanate, and hydroxy group-containing polymerizable compound.

[0055] The contents of the low-viscosity polymerizable compound, polyisocyanate, and hydroxy group-containing polymerizable compound are not particularly limited as long as they exhibit the effect of the primer layer, and are preferably 80.0 to 100.0 mass%, more preferably 85.0 to 100.0 mass%, and more preferably 90.0 to 100.0 mass%, relative to 100 mass% of the primer layer composition (excluding the polymerization initiator).

[0056] The primer layer composition can be prepared by mixing the various components described above simultaneously or sequentially in any order.

[0057] The primer layer composition is irradiated with light and cured to obtain a cured coating layer, which is a primer layer. The primer layer has the function of improving the adhesion between the cured coating layers located on both surfaces of the primer layer, the adhesion between the lens substrate and the lens substrate, and the adhesion between the cured coating layer and the lens substrate. The position of the primer layer is not particularly limited, but from the viewpoint of improving the adhesion between the lens substrate and the cured coating layer (e.g., the photochromic layer), it is preferably between the lens substrate and the cured coating layer (e.g., the photochromic layer).

[0058] The thickness of the primer layer is not particularly limited, but is preferably 1 to 20 μm, more preferably 3 to 15 μm, and particularly preferably 5 to 10 μm. If the thickness is at least the lower limit of the above range, adhesion between the lens substrate and the photochromic layer will be good, and if the thickness is at most the upper limit of the above range, attack on the photochromic layer will be more easily suppressed.

[0059] ((Photochromic Layer-Forming Polymerizable Composition)) One form of the photochromic layer-forming polymerizable composition (hereinafter sometimes simply referred to as "photochromic layer composition") is a photochromic layer composition containing two or more (meth)acrylates and a photochromic compound. The two or more (meth)acrylates function as polymerizable compounds in the photochromic layer composition. Hereinafter, the various components contained in the photochromic layer composition will be described in more detail.

[0060] -Two or more types of (meth)acrylates- The two or more types of (meth)acrylates are not particularly limited, but from the viewpoint of fading rate, it is preferable to include at least a polyfunctional (meth)acrylate having a molecular weight of 500 or more (hereinafter, also referred to as "component A"). The (meth)acrylate other than component A among the two or more types of (meth)acrylates is not particularly limited, but examples thereof include a monofunctional (meth)acrylate (hereinafter, also referred to as "component B"), a polyfunctional (meth)acrylate having no cyclic structure or branched structure (hereinafter, also referred to as "component C"), and a bifunctional (meth)acrylate having at least one structure selected from the group consisting of a cyclic structure and a branched structure (hereinafter, also referred to as "component D"). These may be used alone, or two or more types may be used.

[0061] --Component A-- The molecular weight of Component A is not particularly limited as long as it is 500 or more, but is preferably 600 to 2000, more preferably 650 to 1500, and particularly preferably 700 to 1300. If the molecular weight is equal to or greater than the lower limit of the above range, the fading rate is likely to be improved, while if the molecular weight is equal to or less than the upper limit of the above range, the photochromic layer is likely to have a high hardness.

[0062] The component A is not particularly limited, and examples thereof include bifunctional (meth)acrylates, trifunctional (meth)acrylates, tetrafunctional (meth)acrylates, and pentafunctional (meth)acrylates. These may be used alone or in combination of two or more. Among these, from the viewpoint of weather resistance, bifunctional or trifunctional (meth)acrylates are preferred. The (meth)acryloyl group of the component A may contain only acryloyl groups, may contain only methacryloyl groups, or may contain both acryloyl and methacryloyl groups. That is, component A may be an acrylate or methacrylate.

[0063] One form of the above-mentioned component A includes a non-cyclic polyfunctional (meth)acrylate. In the present disclosure and this specification, "non-cyclic" means not containing a cyclic structure. In contrast, "cyclic" means containing a cyclic structure. The non-cyclic polyfunctional (meth)acrylate refers to a bifunctional or higher functional (meth)acrylate that does not contain a cyclic structure. Specific examples of component A are not particularly limited, and include, for example, polyalkylene glycol di(meth)acrylate represented by the following formula (2). These may be used alone or in combination of two or more.

[0064] ...(2)

[0065] In formula (2), R １ and R ２ each independently represents a hydrogen atom or a methyl group, R represents an alkylene group, and n represents the number of repetitions of the alkoxy group represented by RO, and is 2 or more. The number of carbon atoms of the alkylene group represented by R in formula (2) is not particularly limited, but is preferably 1 to 5, more preferably 2 to 4. The alkylene group represented by R in formula (2) is not particularly limited, but examples include an ethylene group, a propylene group, and a tetramethylene group. The value of n in formula (2) is not particularly limited, but is preferably 2 to 30, more preferably 2 to 25, and particularly preferably 2 to 20. The polyalkylene glycol di(meth)acrylate represented by formula (2) is not particularly limited, but examples include polyethylene glycol di(meth)acrylate, polypropylene glycol di(meth)acrylate, and polytetramethylene glycol di(meth)acrylate. These may be used alone or in combination of two or more.

[0066] A specific example of Component A is a tri(meth)acrylate represented by the following formula (3): The (meth)acryloyl group of the tri(meth)acrylate represented by formula (3) may contain only an acryloyl group, may contain only a methacryloyl group, or may contain both an acryloyl group and a methacryloyl group.

[0067] ...(3)

[0068] In formula (3), R ４０ , R ４１ , R ４４ , R ４５ , R ４７ and R ４８ each independently represents an alkylene group; R ４３ represents an alkyl group, and R ４２ , R ４６ and R ４９ In formula (3), n1 represents a hydrogen atom or a methyl group. ４１ In formula (3), n2 represents the number of repeating alkoxy groups represented by OR ４５ In formula (3), n3 represents the number of repeating alkoxy groups represented by OR ４８ The number of repetitions of the alkoxy group represented by the formula (I) is 2 or more.

[0069] R in formula (3) ４１ , R ４５ and R ４８ The n1, n2, and n3 in formula (3) are as described above for n in formula (2). In formula (3), R ４１ , R ４５ and R ４８ may be the same, or two or three may be different. This also applies to n1, n2, and n3.

[0070] R in formula (3) ４２ , R ４６ and R ４９ each independently represents a hydrogen atom or a methyl group. The tri(meth)acrylate represented by formula (3) may contain only acryloyl groups, only methacryloyl groups, or both acryloyl groups and methacryloyl groups as (meth)acryloyl groups.

[0071] R in formula (3) ４３ The number of carbon atoms in the alkyl group represented by the formula (3) is not particularly limited, but is preferably 1 to 5, and more preferably 1 to 4. ４３The alkyl group represented by the formula (3) is a linear alkyl group or a branched alkyl group. ４３ Specific examples of the alkyl group represented by the formula (I) are not particularly limited, and include, for example, a methyl group and an ethyl group.

[0072] R in formula (3) ４０ , R ４４ and R ４７ R in formula (3) each independently represents an alkylene group. ４０ , R ４４ and R ４７ The number of carbon atoms of the alkylene group represented by the formula (3) is not particularly limited, but is preferably 1 to 5, and more preferably 1 to 4. ４０ , R ４４ and R ４７ Specific examples of the alkylene group represented by the formula (I) are not particularly limited, and include, for example, a methylene group, an ethylene group, a propylene group, and a tetramethylene group.

[0073] The tri(meth)acrylate represented by formula (3) is not particularly limited, and examples thereof include trimethylolpropane polyoxyethylene ether tri(meth)acrylate, etc. These may be used alone or in combination of two or more.

[0074] --Component B-- Component B is a monofunctional (meth)acrylate represented by the following formula (4).

[0075] ...(4)

[0076] In formula (4), R １０ represents a hydrogen atom or a methyl group. The monofunctional (meth)acrylate represented by formula (4) may be an acrylate or a methacrylate.

[0077] In formula (4), R １１ represents a linear alkyl group having 3 or more carbon atoms or a branched alkyl group having 3 or more carbon atoms. １１ The alkyl group represented by the formula (4) may be unsubstituted or may have a substituent. The substituent is not particularly limited, and examples thereof include the various substituents described above.１１ The number of carbon atoms in the linear or branched alkyl group represented by the formula (I) is not particularly limited, but is preferably 3 to 15, more preferably 3 to 14, and particularly preferably 3 to 12. If the number is equal to or greater than the lower limit of the above range, the color density of the photochromic layer tends to be high, whereas if the number is equal to or less than the upper limit of the above range, the photochromic compound tends to be soluble in the composition for photochromic layer.

[0078] The molecular weight of the monofunctional (meth)acrylate represented by formula (4) may be, for example, 100 to 300. However, it is not limited to the above range. As described above, in one embodiment, the monofunctional (meth)acrylate represented by formula (4) may be a monofunctional (meth)acrylate having a molecular weight of 150 or less. Specific examples of the monofunctional (meth)acrylate represented by formula (4) are not particularly limited, and include, for example, n-butyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, isodecyl (meth)acrylate, n-lauryl (meth)acrylate, etc. These may be used alone or in combination of two or more.

[0079] The polyfunctional (meth)acrylate other than Component A that may be contained in the two or more (meth)acrylates is not particularly limited. However, from the viewpoint of increasing the (meth)acryloyl group content in the photochromic layer composition and forming a rigid polymer network between molecules, a (meth)acrylate with a high proportion of (meth)acryloyl groups in the molecule is preferred. From this viewpoint, a polyfunctional (meth)acrylate with a lower molecular weight than Component A is preferred. The molecular weight of the polyfunctional (meth)acrylate other than Component A is not particularly limited. From the viewpoint described above, it is preferably 100 or more but less than 500, more preferably 100 to 400, and particularly preferably 100 to 350. The number of functional groups of the polyfunctional (meth)acrylate other than Component A is not particularly limited. However, from the viewpoint of weather resistance, a polyfunctional (meth)acrylate with a higher functionality than the polyfunctional (meth)acrylate used as Component A is preferred. The number of functional groups of the polyfunctional (meth)acrylate may be, for example, 10 to 15. The polyfunctional (meth)acrylate having 10 to 15 functional groups is not particularly limited, and examples thereof include poly[(3-methacryloyloxypropyl)silsesquioxane] derivatives, etc. These may be used alone or in combination of two or more.

[0080] The polyfunctional (meth)acrylate is not particularly limited, and examples thereof include a polyfunctional (meth)acrylate (component C) having no cyclic structure or branched structure, and a bifunctional (meth)acrylate (component D) having at least one structure selected from the group consisting of a cyclic structure and a branched structure. These may be used alone or in combination of two or more. Component C and component D will be described in more detail below.

[0081] --Component C-- Component C is a polyfunctional (meth)acrylate having neither a cyclic structure nor a branched structure, represented by the following formula (5).

[0082] ...(5)

[0083] In formula (5), R ３ and R ４each independently represents a hydrogen atom or a methyl group. In formula (5), m represents an integer of 1 or more, and may be 10 or less, 9 or less, 8 or less, 7 or less, or 6 or less. When component C has a methacryloyl group, the branched structure contained in the methacryloyl group is not taken into consideration.

[0084] The molecular weight of Component C is not particularly limited, but is preferably 100 to 400, more preferably 140 to 350, and particularly preferably 160 to 300. If the molecular weight is equal to or greater than the lower limit of the above range, the fading rate tends to be improved, whereas if the molecular weight is equal to or less than the upper limit of the above range, the color density of the photochromic layer tends to be high.

[0085] Component C may contain only acryloyl groups, only methacryloyl groups, or both acryloyl and methacryloyl groups as (meth)acryloyl groups. Specific examples of component C are not particularly limited, and include, for example, 1,9-nonanediol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, and 1,10-decanediol di(meth)acrylate. These may be used alone, or two or more may be used.

[0086] --Component D-- Component D is a bifunctional (meth)acrylate containing at least one structure selected from the group consisting of a cyclic structure and a branched structure. It is presumed that the inclusion of Component D in the composition for photochromic layer contributes to improving the color density of the photochromic layer formed from the composition for photochromic layer. One embodiment of Component D contains one or more cyclic structures and no branched structures per molecule; another embodiment contains one or more branched structures and no cyclic structures per molecule; and still another embodiment contains one or more cyclic structures and one or more branched structures per molecule. The number of at least one structure selected from the group consisting of cyclic structures and branched structures contained in Component D is not particularly limited, but is preferably 1 to 3, more preferably 1 to 2, and particularly preferably 1. When Component D contains a methacryloyl group, the branched structure contained in the methacryloyl group is not taken into consideration.

[0087] One example of component D containing one or more cyclic structures is an alicyclic bifunctional (meth)acrylate. The alicyclic bifunctional (meth)acrylate is not particularly limited, and examples thereof include R １１１ - (L １１ ) ｎ１１ -Q-(L ２２ ) ｎ２２ -R ２２２ Here, Q represents a divalent alicyclic group, and R １１１ and R ２２２ each independently represents a (meth)acryloyl group or a (meth)acryloyloxy group, L １１ and L ２２ each independently represents a linking group, and n11 and n22 each independently represent 0 or 1. The divalent alicyclic group represented by Q is not particularly limited, and suitable examples include alicyclic hydrocarbon groups having 3 to 20 carbon atoms, such as a cyclopentylene group, a cyclohexylene group, a cycloheptylene group, a cyclooctylene group, a tricyclodecanylene group, and an adamantylene group. １１ and L ２２ The linking group represented by the formula (I) is not particularly limited, and examples thereof include alkylene groups having 1 to 6 carbon atoms.

[0088] Specific examples of alicyclic bifunctional (meth)acrylates are not particularly limited and include, for example, cyclohexanedimethanol di(meth)acrylate, ethoxylated cyclohexanedimethanol di(meth)acrylate, propoxylated cyclohexanedimethanol di(meth)acrylate, ethoxylated propoxylated cyclohexanedimethanol di(meth)acrylate, tricyclodecane dimethanol di(meth)acrylate, ethoxylated tricyclodecane dimethanol di(meth)acrylate, propoxylated tricyclodecane dimethanol di(meth)acrylate, ethoxylated propoxylated tricyclodecane dimethanol di(meth)acrylate, etc. These may be used alone or in combination of two or more.

[0089] An example of component D containing one or more branched structures is a bifunctional (meth)acrylate containing a branched alkylene group. The number of carbon atoms in the branched alkylene group is not particularly limited, but is preferably 1 to 10, more preferably 2 to 9, even more preferably 3 to 8, and particularly preferably 4 to 7. One form of branched alkylene group may contain a quaternary carbon (i.e., a carbon bonded to four carbons). Specific examples of component D containing one or more branched structures are not particularly limited, and include, for example, neopentyl glycol di(meth)acrylate, ethoxylated neopentyl glycol di(meth)acrylate, and propoxylated neopentyl glycol di(meth)acrylate. These may be used alone, or two or more may be used.

[0090] The molecular weight of Component D is not particularly limited, but is preferably 200 to 400. If the molecular weight is equal to or greater than the lower limit of the above range, the color density of the photochromic layer is likely to be improved, and if the molecular weight is equal to or less than the upper limit of the above range, the photochromic compound is likely to be soluble in the composition for the photochromic layer.

[0091] The component D may contain only acryloyl groups, only methacryloyl groups, or both acryloyl groups and methacryloyl groups as (meth)acryloyl groups.

[0092] The content of the polymerizable compound (i.e., the total content of multiple polymerizable compounds) is not particularly limited, but is preferably 70 to 99% by mass, and more preferably 80 to 95% by mass, relative to 100% by mass of the composition for photochromic layer. When the content is equal to or greater than the lower limit of the above range, the photochromic compound is more likely to dissolve in the composition for photochromic layer, and when the content is equal to or less than the upper limit of the above range, the photochromic properties are more likely to be improved. The composition for photochromic layer may or may not contain a solvent. When a solvent is contained, 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.

[0093] The content of Component A is not particularly limited, but is preferably 50 to 95% by mass, more preferably 55 to 92% by mass, and particularly preferably 60 to 90% by mass, based on 100% by mass of all polymerizable compounds contained in the composition for photochromic layer. When the content is equal to or greater than the lower limit of the above range, the fading rate is likely to be improved, and when the content is equal to or less than the upper limit of the above range, weather resistance is likely to be improved. In this disclosure and this specification, a component that corresponds to both Component A and Component C, or Component A and Component D, is considered to be Component A. In one embodiment, Component A may be the component that accounts for the largest proportion of the multiple polymerizable compounds contained in the composition. In one embodiment, the composition for photochromic layer may contain only one type of Component A, while in another embodiment, it may contain two or more types of Component A. When two or more types of Component A are contained, the content of Component A is the total content of the two or more types. This also applies to the contents of the other components.

[0094] The content of Component B is not particularly limited, but is preferably 1 to 30% by mass, more preferably 5 to 27% by mass, and particularly preferably 10 to 25% by mass, based on 100% by mass of all polymerizable compounds contained in the composition for photochromic layer. When the content is equal to or greater than the lower limit of the above range, weather resistance is likely to be improved, while when the content is equal to or less than the upper limit of the above range, the fading rate is likely to be improved. In one embodiment of the composition for photochromic layer, only one type of Component B may be contained, and in another embodiment, two or more types of Component B may be contained. When two or more types of Component B are contained, the content of Component B is the total content of the two or more types.

[0095] The content of Component C is not particularly limited, but is preferably 1 to 30% by mass, and more preferably 3 to 27% by mass, relative to 100% by mass of all polymerizable compounds contained in the composition for photochromic layer. If the content is equal to or greater than the lower limit of the above range, the color density tends to be high, and if the content is equal to or less than the upper limit of the above range, the fading rate tends to be improved. In one embodiment of the composition for photochromic layer, only one type of Component C may be contained, and in another embodiment, two or more types of Component C may be contained. When two or more types of Component C are contained, the content of Component C is the total content of the two or more types.

[0096] The content of Component D is not particularly limited, but is preferably 1 to 30% by mass, and more preferably 5 to 27% by mass, relative to 100% by mass of all polymerizable compounds contained in the composition for photochromic layer. When the content is equal to or greater than the lower limit of the above range, the color density of the photochromic layer is likely to be improved, while when the content is equal to or less than the upper limit of the above range, the photochromic compound is likely to dissolve in the composition for photochromic layer. In one embodiment, the composition for photochromic layer may contain only one type of Component D, and in another embodiment, it may contain two or more types of Component D. When two or more types of Component D are contained, the content of Component D is the total content of the two or more types.

[0097] The composition for photochromic layer may, if necessary, contain another (meth)acrylate other than components A to D. When the composition contains another (meth)acrylate other than components A to D, the content of the other (meth)acrylate other than components A to D is not particularly limited, but from the viewpoint of the fading rate, it is preferably 10.0 mass% or less, and more preferably 5.0 mass% or less, relative to 100 mass% of all (meth)acrylates contained in the composition for photochromic layer. The composition for photochromic layer may, if necessary, contain another polymerizable compound other than (meth)acrylate.

[0098] Photochromic Compound—One embodiment of the composition for photochromic layer may contain a photochromic compound together with the polymerizable compound. The photochromic compound is not particularly limited, and for example, a known compound that exhibits photochromic properties when exposed to ultraviolet light can be used. Specific examples of the photochromic compound are not particularly limited and include compounds having a known skeleton that exhibits photochromic properties, such as azobenzenes, spiropyrans, spirooxazines, naphthopyrans, indenonaphthopyrans, phenanthropyrans, hexaallylbismidazoles, donor-acceptor Stenhouse adducts (DASA), salicylideneanilines, dihydropyrenes, anthracene dimers, fulgides, diarylethenes, phenoxynaphthacenequinones, and stilbenes; fulgimide compounds; spirooxazine compounds; chromene compounds; indeno-fused naphthopyran compounds; and at least one compound selected from the group consisting of photochromic compounds represented by general formula A, photochromic compounds represented by general formula B, and photochromic compounds represented by general formula C, as described in WO 2022 / 138966. These compounds may be used alone or in combination of two or more. The content of the photochromic compound is not particularly limited, but is preferably about 0.1 to 15% by mass relative to 100% by mass of the composition for the photochromic layer.

[0099] -Other Components- In addition to the two or more (meth)acrylates and the photochromic compound, the composition for photochromic layer may contain, as necessary, one or more of various additives that may be typically contained in polymerizable compositions, in any amount. The additives that may be contained in the composition for photochromic layer are not particularly limited, and examples thereof include a polymerization initiator for promoting a polymerization reaction.

[0100] The polymerization initiator is not particularly limited, and examples thereof include a photoradical polymerization initiator and a thermal polymerization initiator. These may be used alone or in combination of two or more. Among these, a photoradical polymerization initiator is preferred from the viewpoint of progressing the polymerization reaction in a short time.

[0101] The photoradical polymerization initiator is not particularly limited, and examples thereof include benzoin ketals such as 2,2-dimethoxy-1,2-diphenylethan-1-one; α-hydroxyketones such as 1-hydroxycyclohexyl phenyl ketone, 2-hydroxy-2-methyl-1-phenylpropan-1-one, and 1-[4-(2-hydroxyethoxy)phenyl]-2-hydroxy-2-methyl-1-propan-1-one; 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)-butan-1-one, and 1,2-methyl-1-[4-(methyl α-aminoketones such as 1-[(4-phenylthio)phenyl]-2-morpholinopropan-1-one; oxime esters such as 1-[(4-phenylthio)phenyl]-1,2-octadione-2-(benzoyl)oxime; phosphine oxides such as bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide, bis(2,6-dimethoxybenzoyl)-2,4,4-trimethylpentylphosphine oxide, and 2,4,6-trimethylbenzoyldiphenylphosphine oxide; 2-(o-chlorophenyl)-4,5-diphenylimidazole 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, N,N'-tetramethyl-4,4'-diaminobenzophenone, N,N'-tetraethyl-4,4'-diaminobenzophenone, 4-methoxyphenyl benzophenone compounds such as 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-phenanthraquinone, 2-methyl-1,4-naphthoquinone, and 2,3-dimethylanthraquinone;Examples of suitable benzoin compounds include 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 benzyl dimethyl ketal; acridine compounds such as 9-phenylacridine and 1,7-bis(9,9'-acridinylheptane); N-phenylglycine; and coumarin. These compounds may be used alone or in combination of two or more. Among these, α-hydroxyketones and phosphine oxides are preferred from the viewpoints of curability, transparency, and heat resistance. In the 2,4,5-triarylimidazole dimer, the substituents on the aryl groups of the two triarylimidazole moieties may be the same and form a symmetrical compound, or different and form an asymmetrical compound. Furthermore, a thioxanthone compound may be combined with a tertiary amine, such as a combination of diethylthioxanthone and dimethylaminobenzoic acid. The content of the polymerization initiator is not particularly limited, but is preferably about 0.1 to 5.0% by mass relative to 100% by mass of the composition for the photochromic layer.

[0102] If necessary, the composition for the photochromic layer may further contain any amount of known additives that can be commonly added, such as surfactants, antioxidants, radical scavengers, light stabilizers, ultraviolet absorbers, color inhibitors, antistatic agents, fluorescent dyes, dyes, pigments, fragrances, plasticizers, silane coupling agents, etc. These may be used alone or in combination of two or more.

[0103] The composition for the photochromic layer can be prepared by mixing the various components described above simultaneously or sequentially in any order.

[0104] The photochromic layer composition is irradiated with light and cured to obtain a photochromic layer, which is a cured coating layer. The photochromic layer exhibits photochromic properties, i.e., develops color under light in a predetermined wavelength range (e.g., outdoors) and fades under light outside the predetermined wavelength range (e.g., indoors). The location of the photochromic layer is not particularly limited, but is preferably between the primer layer and the protective layer described below from the viewpoints of adhesion to the lens substrate and protection of the photochromic layer.

[0105] The thickness of the photochromic layer is not particularly limited, but is preferably 5 to 80 μm, more preferably 10 to 70 μm, and particularly preferably 15 to 60 μm. If the thickness is equal to or greater than the lower limit of the above range, the color density tends to become high, while if the thickness is equal to or less than the upper limit of the above range, transparency tends to be maintained.

[0106] ((Polymerizable composition for forming protective layer)) One embodiment of the above-mentioned polymerizable composition for forming a protective layer (hereinafter sometimes simply referred to as "protective layer composition") is a polymerizable composition containing one or more (meth)acrylates and containing 70.0 mass% or more of an alicyclic bifunctional (meth)acrylate relative to 100 mass% of all (meth)acrylates. Note that there are no particular restrictions on the components contained in the protective layer composition, but from the viewpoint of the hardness and solvent resistance of the protective layer, it is preferable that the composition contain an alicyclic bifunctional (meth)acrylate.

[0107] The alicyclic bifunctional (meth)acrylate contained in the protective layer composition can be the alicyclic bifunctional (meth)acrylate described above as an example of the polymerizable composition for forming a photochromic layer. The content of the alicyclic bifunctional (meth)acrylate is not particularly limited relative to 100% by mass of all (meth)acrylates, but from the viewpoint of achieving higher hardness and superior solvent resistance in the protective layer, it is preferably 70.0% by mass or more, more preferably 75.0% by mass or more, even more preferably 85.0% by mass or more, and particularly preferably 95.0% by mass or more. As one embodiment of the content of the alicyclic bifunctional (meth)acrylate, the total amount of (meth)acrylate may be the alicyclic bifunctional (meth)acrylate.

[0108] In one embodiment, the protective layer composition may contain one or more other (meth)acrylates in addition to an alicyclic bifunctional (meth)acrylate as the (meth)acrylate. In another embodiment, the (meth)acrylate may contain only an alicyclic bifunctional (meth)acrylate. In the former embodiment, the other (meth)acrylate contained together with the alicyclic bifunctional (meth)acrylate is not particularly limited, and one or more of various (meth)acrylates can be used. Specific examples of the other (meth)acrylate are not particularly limited, and include, for example, monofunctional, bifunctional, trifunctional, tetrafunctional, and pentafunctional (meth)acrylates, which may be acyclic or cyclic. The (meth)acrylate containing a cyclic structure may have an alicyclic structure as the cyclic structure, or may have another cyclic structure. For the alicyclic structure, see the above description of the alicyclic bifunctional (meth)acrylate. The content of the other (meth)acrylates is not particularly limited, but from the viewpoint of obtaining high hardness and excellent solvent resistance in the protective layer of the present disclosure, the content is preferably 0 to 30.0 mass%, more preferably 1.0 to 25.0 mass%, and particularly preferably 5.0 to 20.0 mass%, relative to 100 mass% of all (meth)acrylates.

[0109] The protective layer composition contains at least one (meth)acrylate as a polymerizable compound, and in one embodiment, may contain one or more polymerizable compounds other than (meth)acrylate. In another embodiment, the protective layer composition may contain only (meth)acrylate as the polymerizable compound. The other polymerizable compounds are not particularly limited, and one or more known polymerizable compounds may be used. The content of the (meth)acrylate is not particularly limited, but from the viewpoint of durability, it is preferably 80.0% by mass or more, more preferably 90.0% by mass or more, and particularly preferably 100% by mass, of the total polymerizable compounds in the protective layer composition (100% by mass).

[0110] In one embodiment, the content of the above (meth)acrylate (the total amount when two or more types of (meth)acrylates are included) is preferably 80.0 mass% or more, more preferably 90.0 mass% or more, and particularly preferably 95.0 mass% or more, based on 100 mass% of the composition for the protective layer.

[0111] The composition for a protective layer may or may not contain a solvent. When the composition for a protective layer contains a solvent, any solvent can be used in any amount without any particular limitation as long as it does not inhibit the progress of the polymerization reaction of the polymerizable composition.

[0112] The protective layer composition may further contain one or more additives at any content, as needed. The additives are not particularly limited, and examples thereof include various known additives such as a polymerization initiator for promoting a polymerization reaction and a leveling agent for improving the coating suitability of the composition. These may be used alone or in combination of two or more.

[0113] The polymerization initiator is not particularly limited, and examples thereof include photoradical polymerization initiators and thermal polymerization initiators. These may be used alone or in combination of two or more. Among these, photoradical polymerization initiators are preferred from the viewpoint of progressing the polymerization reaction in a short time. Specific examples of photoradical polymerization initiators can be found in the polymerization initiators that can be contained in the polymerizable composition for forming a photochromic layer described above. The content of the polymerization initiator is not particularly limited, but from the viewpoint of the efficiency of forming the protective layer, it is preferably 0.1 to 5.0% by mass relative to 100% by mass of the composition for forming the protective layer.

[0114] The composition for the protective layer may further contain an ultraviolet absorber, if necessary. The ultraviolet absorber is not particularly limited, and examples thereof include 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-diviphenyl-s-triazine, and 2-[[2-hydroxy-4-[1-(2-ethylhexyloxycarbonyl)ethyloxy]phenyl]]-4,6-diphenyl-s-triazine; and benzotriazole compounds 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. These may be used alone or in combination of two or more. The ultraviolet absorber can contribute to improving the weather resistance of the protective layer by being contained in the composition for protective layer. When the composition for protective layer contains an ultraviolet absorber, the content of the ultraviolet absorber is not particularly limited, and is preferably 0.1 to 1.0 mass % relative to 100 mass % of the composition for protective layer from the viewpoint of optical properties such as transparency.

[0115] The composition for the protective layer can be prepared by mixing the various components described above simultaneously or sequentially in any order.

[0116] The protective layer composition is irradiated with light and cured to obtain a cured coating layer, i.e., a protective layer. The protective layer has scratch resistance. The position of the protective layer is not particularly limited, but is preferably on the cured coating layer (e.g., a photochromic layer) from the viewpoint of protecting the cured coating layer (e.g., a photochromic layer). From this viewpoint, the protective layer preferably has high hardness. The protective layer is not particularly limited, but preferably has excellent solvent resistance. In the manufacturing process of optical articles, after a layer is formed, a wiping process with a solvent is usually performed to clean the surface of the formed layer. However, if the protective layer is damaged during this wiping process, it can cause haze or optical defects in the finished lens.

[0117] The thickness of the protective layer is not particularly limited, but is preferably 10 to 50 μm, more preferably 12 to 45 μm, and particularly preferably 15 to 40 μm. If the thickness is equal to or greater than the lower limit of the above range, the durability of the finished lens will be good, and if the thickness is equal to or less than the upper limit of the above range, the transmittance (transparency) of the cured coating layer will be easily maintained.

[0118] One embodiment of a finished lens manufactured by a method for manufacturing a finished lens according to one aspect of the present disclosure may have a layer structure of "photochromic layer / protective layer." With regard to the layer structure, " / " is used to encompass both a structure in which the layers are in direct contact without any other layer intervening therebetween and a structure in which the layers are provided via one or more other layers. Furthermore, in one embodiment, the optical article may have a layer structure of "photochromic layer / protective layer / other cured coating layer." The other cured coating layer is not particularly limited, and examples thereof include a cured coating layer generally referred to as a hard coat layer. These may be used alone or in combination of two or more. Providing a hard coat layer in addition to the protective layer can further enhance the durability of the optical article. Furthermore, in one embodiment, providing a hard coat layer can also enhance the impact resistance of the optical article. In one embodiment, the other cured coating layer may be in direct contact with the protective layer without any other layer intervening therebetween.

[0119] The thickness of the other cured coating layer is not particularly limited, but is preferably 1 to 10 μm, more preferably 1 to 8 μm, and particularly preferably 1 to 5 μm, from the viewpoint of optical properties such as refractive index, etc. In one embodiment, the other cured coating layer can be a layer thinner than the protective layer.

[0120] In one embodiment, the hard coat layer can be formed by irradiating and / or heating a polymerizable composition for forming a hard coat layer (hereinafter, sometimes simply referred to as a "hard coat layer composition"). The hard coat layer is not particularly limited, and examples thereof include an organosilicon-based cured coating layer. An organosilicon-based cured coating layer is generally preferred because it has excellent impact resistance. Furthermore, in one embodiment, when an antireflection layer is further provided, an organosilicon-based cured coating layer is generally preferred because it has excellent adhesion to the antireflection layer.

[0121] The organosilicon-based cured coating layer is a cured coating layer obtained by curing a hard coat layer composition containing an organosilicon compound. The organosilicon compound is not particularly limited, and examples include organosilicon compounds capable of generating silanol groups upon polymerization, such as γ-glycidoxypropyltrimethoxysilane; organopolysiloxanes such as water-dispersed colloidal silica having reactive groups such as halogen atoms or amino groups that undergo condensation reaction with silanol groups; and silane coupling agents having a polymerizable group such as a vinyl group, an allyl group, a (meth)acryloyl group, or a (meth)acryloyloxy group and a hydrolyzable group such as an alkoxy group. These may be used alone or in combination of two or more. The hard coat layer composition containing the organosilicon compound may further contain silicon oxide; particles of an inorganic substance such as titanium oxide; or the like, as necessary, for adjusting the refractive index, etc. In addition to the above, the hard coat layer composition containing an organosilicon compound may further contain, as necessary, a curing agent such as aluminum acetylacetonate to improve the hardness of the hard coat layer; a surfactant such as a silicone surfactant to control liquid dispersibility and interfacial tension; etc. For details of the polymerizable composition containing an organosilicon compound, known techniques related to organosilicon-based cured coating layers that can function as hard coat layers can be applied. The polymerizable composition containing an organosilicon compound can be cured by promoting a polymerization reaction through light irradiation and / or heat treatment, depending on the types of components contained in the composition.

[0122] The composition for a hard coat layer may or may not contain a solvent. When the composition for a hard coat layer contains a solvent, any solvent can be used in any amount without any particular limitation as long as it does not inhibit the progress of the polymerization reaction of the polymerizable composition.

[0123] When the other cured coating layer is provided on the protective layer, there is no particular limitation, but from the viewpoint of preventing foreign matter from being interposed between the protective layer and the other cured coating layer, it is preferable to perform a solvent wiping treatment on the surface of the protective layer.However, if the protective layer has poor solvent resistance, the solvent wiping treatment will damage the protective layer (for example, cause surface roughness), which will cause haze and optical defects in the finished lens including the protective layer.In contrast, the protective layer formed from the above-mentioned protective layer composition exhibits excellent solvent resistance, and therefore can be said to be suitable for providing the other cured coating layer on the protective layer.

[0124] The wiping treatment with a solvent is not particularly limited and can be performed by a known method, for example, wiping the surface of the protective layer with a cloth soaked in the solvent. The solvent is not particularly limited and examples thereof include ketone solvents such as acetone; alcohol solvents such as ethanol and isopropyl alcohol; and the like. These may be used alone or in combination of two or more. In one embodiment, the protective layer preferably has high resistance to ketone solvents that are commonly used as wiping solvents during the production of optical articles.

[0125] ((Other Photocurable Compositions)) The photocurable composition may or may not further contain other photocurable compositions, as necessary, in addition to the above-mentioned composition for primer layer, composition for photochromic layer, and composition for protective layer. The other photocurable compositions are not particularly limited, and examples thereof include compositions that exhibit antireflection properties, compositions that exhibit antifouling properties, and photocurable compositions that exhibit antifogging properties after curing. These may be used alone or in combination of two or more.

[0126] The total thickness of the cured coating layers (excluding the hard coat layer) is not particularly limited, but is preferably 40 to 100 μm, more preferably 45 to 95 μm, and particularly preferably 50 to 90 μm. If the thickness is equal to or greater than the lower limit of the above range, adhesion is easily maintained, and if the thickness is equal to or less than the upper limit of the above range, the transmittance (transparency) of the cured coating layer is easily maintained.

[0127] <Spraying Step> The spraying step in the method for producing a finished lens according to one embodiment of the present disclosure is a step of spraying an inert gas toward the other surface of the lens substrate on which the photocurable composition is not applied, and may or may not include other treatments. The spraying step is performed after the above-mentioned application step, and it is sufficient that the spraying step be started before the lens is thermally deformed in the curing step described below. Therefore, one mode of starting the spraying step is that the spraying step may be started before the curing step described below is started, may be started simultaneously with the curing step described below, or may be started after the curing step described below is started. Among these, from the viewpoint of preventing thermal deformation of the finished lens, it is preferable to start the spraying step before the curing step described below is carried out.

[0128] The spraying in the spraying step may be continuous or intermittent. Of these, continuous spraying is preferred from the viewpoint of preventing thermal deformation of the finished lens. Furthermore, the spray angle with respect to the other surface of the lens substrate is not particularly limited, but from the viewpoint of cooling effect, it is preferably 60 to 90°, more preferably 75 to 90°, and particularly preferably 80 to 90°.

[0129] The injection step may be performed in a furnace in which the curing step described below is performed, or may be performed outside of a furnace. Among these, the furnace in which the curing step described below is performed is preferred from the viewpoint of improved workability due to the ability to simultaneously perform the injection and curing steps. When the injection step is performed in a furnace, the injection rate of the inert gas is not particularly limited, but is preferably 0.5 to 4.0 times / min, more preferably 0.7 to 3.0 times / min, and particularly preferably 1.0 to 2.0 times / min relative to the volume of the furnace. A rate equal to or greater than the lower limit of the above range facilitates stable supply of the inert gas, while a rate equal to or less than the upper limit of the above range facilitates cooling of the other surface of the lens. The "injection rate" is the ratio of the volume of the furnace to the value measured by adjusting the needle valve using a small flow sensor (MF-F series, manufactured by Horiba, Ltd.).

[0130] The injection rate of the inert gas is not particularly limited, but is preferably 0.8 to 7.0 L / min, more preferably 1.0 to 5.0 L / min, and particularly preferably 1.5 to 3.5 L / min. A rate equal to or higher than the lower limit of the above range facilitates stable supply of the inert gas, while a rate equal to or lower than the upper limit of the above range facilitates cooling of the other surface of the lens. The "injection rate" is a value measured by adjusting the needle valve using a small flow sensor (MF-F series, manufactured by Horiba, Ltd.).

[0131] Examples of the inert gas include nitrogen gas, argon gas, and carbon dioxide gas. These may be used alone or in combination of two or more. Among these, from the viewpoints of economy and availability, nitrogen gas and argon gas are preferred, and nitrogen gas is more preferred.

[0132] The number of the inert gas injection ports is not particularly limited, and may be one or two or more.

[0133] The position on the lens substrate where the spray is applied may be the central portion of the lens substrate, the peripheral portion of the lens substrate, etc. These may be used alone or in combination of two or more types. Of these, the central portion of the lens substrate is preferred from the viewpoint of effectively suppressing thermal deformation of the finished lens.

[0134] There are no particular restrictions on the temperature of the inert gas, and it may be, for example, 0° C. or lower, higher than 0° C. and lower than 20° C., room temperature, or higher than 20° C. Among these, room temperature is preferred from the viewpoints of sufficiently preventing thermal deformation of the lens substrate and preventing the operation of the spraying step from becoming complicated.

[0135] <Curing Step> The curing step in the method for producing a finished lens according to one embodiment of the present disclosure is a step of curing the applied photocurable composition by light irradiation while the above-described spraying step is being carried out, and may or may not include other treatments. The curing step is a step carried out after the above-described application step, and it is sufficient that the above-described spraying step is started before the lens is thermally deformed. Therefore, in one embodiment, the curing step may be started after the above-described spraying step is started, may be started simultaneously with the above-described spraying step, or may be started before the above-described spraying step. Among these, from the viewpoint of preventing thermal deformation of the finished lens, it is preferable to start the curing step after the above-described spraying step is started.

[0136] The light irradiation in the curing step may be continuous or intermittent, with continuous light irradiation being preferred from the viewpoint of productivity.

[0137] The environment during light irradiation in the curing step is not particularly limited, and may be, for example, an inert gas atmosphere or may not be an inert gas atmosphere. Among these, an inert gas atmosphere is preferred from the viewpoint of the curing efficiency of the photocurable composition. One form of the environment is a furnace under an inert gas atmosphere. The inert gas used to create the inert gas atmosphere is not particularly limited, and examples include nitrogen gas, argon gas, carbon dioxide gas, etc. These may be used alone or in combination of two or more. Among these, from the viewpoints of economy and ease of availability, nitrogen gas and argon gas are preferred, and nitrogen gas is more preferred. Furthermore, the inert gas used to create the inert gas atmosphere may be the same as or different from the inert gas used for spraying in the spraying step.

[0138] The method for creating the inert gas atmosphere is not particularly limited, but examples include a method of reducing the pressure inside the furnace and then introducing an inert gas to create an inert gas atmosphere, and a method of introducing an inert gas into the furnace and pushing out the air inside the furnace to create an inert gas atmosphere. These methods may be used alone or in combination of two or more. One method for maintaining the inert gas atmosphere is to continuously introduce an inert gas into the furnace while venting the inert gas from the furnace in an amount equal to the amount introduced. When maintaining the inert gas atmosphere using this method, the amount of inert gas introduced to maintain the inert gas atmosphere (hereinafter, sometimes simply referred to as the "introduced amount of inert gas for atmosphere maintenance"; when the inert gas is nitrogen gas, sometimes simply referred to as the "introduced amount of nitrogen gas for atmosphere maintenance") is not particularly limited, and is preferably 1 to 100 times / min, more preferably 3 to 60 times / min, and particularly preferably 7 to 30 times / min relative to the volume of the furnace. A rate equal to or greater than the lower limit of the above range facilitates stable supply of the inert gas, while a rate equal to or less than the upper limit of the above range reduces the likelihood of inert gas replacement, i.e., oxygen contamination. The "amount of inert gas introduced for maintaining the atmosphere" is a volume ratio of the furnace measured by adjusting a needle valve using a small flow sensor (MF-F series manufactured by Horiba, Ltd.).

[0139] The temperature of the inert gas for creating the inert gas atmosphere is not particularly limited, and may be, for example, 0° C. or lower, higher than 0° C. and lower than 20° C., room temperature, or higher than 20° C. Among these, room temperature is preferred from the viewpoint of achieving excellent curing efficiency of the photocurable composition while preventing the curing step from becoming complicated.

[0140] The conditions for light irradiation in the curing step are not particularly limited, and the intensity of light irradiation, the irradiation time, the amount of exposure to light irradiation, etc. can be determined depending on the types and compositions of the various components contained in the photocurable composition.

[0141] The intensity of light irradiation during curing of the primer layer composition is not particularly limited, and may be, for example, 132 to 198 mW / cm ２The time of light irradiation during curing of the primer layer composition is not particularly limited and can be, for example, 4 to 6 seconds. The exposure dose of light irradiation during curing of the primer layer composition is not particularly limited and can be, for example, 520 to 1190 mJ / cm. ２ This can be done.

[0142] The intensity of light irradiation when curing the composition for photochromic layer is not particularly limited, and may be, for example, 132 to 198 mW / cm ２ The light irradiation time during curing of the composition for photochromic layer is not particularly limited and can be, for example, 32 to 48 seconds. The exposure dose of light irradiation during curing of the composition for photochromic layer is not particularly limited and can be, for example, 4220 to 9510 mJ / cm. ２ This can be done.

[0143] The intensity of light irradiation when curing the composition for the protective layer is not particularly limited, and may be, for example, 132 to 198 mW / cm ２ The light irradiation time during curing of the protective layer composition is not particularly limited and can be, for example, 12 to 18 seconds. The exposure dose of light irradiation during curing of the protective layer composition is not particularly limited and can be, for example, 1580 to 3570 mJ / cm. ２ This can be done.

[0144] The curing step may or may not include other treatments as necessary in addition to curing the applied photocurable composition by light irradiation. Examples of other treatments in the curing step include, but are not limited to, annealing (heat treatment) after light irradiation. Annealing can improve the adhesion of each cured coating layer. The conditions for the annealing are not particularly limited, but it is preferable to perform the annealing in a heat treatment furnace at an atmospheric temperature of about 90 to 130°C for 0.5 to 4 hours.

[0145] The present disclosure will be further described below with reference to examples, but the present disclosure is not limited to the embodiments shown in the examples.

[0146] [Preparation of Polymerizable Composition for Forming Photochromic Layer] In a plastic container, polyethylene glycol dimethacrylate ((in the above formula (2), n=14, R=ethylene group, R １ and R ２ 90 parts by mass of methyl acrylate (number average molecular weight 726) and 10 parts by mass of tricyclodecane dimethanol dimethacrylate (molecular weight 332) were mixed together to obtain a mixture of polymerizable compounds. The thus-obtained mixture of polymerizable compounds was mixed with a photochromic compound (an indeno-fused naphthopyran compound represented by the following structural formula (6) described in U.S. Pat. No. 5,645,767), a photoradical polymerization initiator (bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide, manufactured by IGM Resin B.V., Omnirad 819), an antioxidant (ethylene bis(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. The mixture was then degassed using a rotation-revolution type stirring and degassing apparatus. Thus, a composition for photochromic layer 1 was obtained. The contents of the various components were as follows, relative to 100% by mass of the composition 1 for photochromic layer: the mixture of polymerizable compounds was 90.0% by mass, the photochromic compound was 5.7% by mass, the photoradical polymerization initiator was 0.7% by mass, the antioxidant was 2.7% by mass, and the light stabilizer was 0.9% by mass.

[0147] ...(6)

[0148] [Preparation of Polymerizable Composition for Forming Primer Layer] In a plastic container, 10 parts by mass of a hydroxyl group-containing bifunctional acrylate having a compound represented by the following structural formula (1), 40 parts by mass of polyisocyanate (Coronate 2715, manufactured by Tosoh Corporation), and 50 parts by mass of 2-phenoxyethyl acrylate (viscosity: 13 cP) were mixed. To the mixture thus obtained, 0.02 parts by mass of a photoradical polymerization initiator (bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide, Omnirad 819, manufactured by IGM Resin B.V.) was added relative to the total amount of 100 parts by mass of the mixture, and the mixture was thoroughly stirred. The mixture was then degassed using a rotation-revolution type stirring / degassing apparatus. Thus, primer layer composition 1 was obtained.

[0149] ...(1)

[0150] [Preparation of Polymerizable Composition for Forming Protective Layer] In a plastic container, 99.0 parts by mass of tricyclodecane dimethanol diacrylate (alicyclic bifunctional (meth)acrylate) and 1.0 part by mass of a photoradical polymerization initiator (bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide, Omnirad 819, manufactured by IGM Resin B.V.) were mixed and thoroughly stirred, and then degassed using a rotation-revolution type stirring and degassing apparatus. In this way, protective layer composition 1 was obtained. Note that in the above protective layer composition 1, the only (meth)acrylate was the alicyclic bifunctional (meth)acrylate, and therefore the content of the alicyclic bifunctional (meth)acrylate was 100% by mass, with the total (meth)acrylate being 100% by mass.

[0151] [Preparation of Polymerizable Composition for Forming Hard Coat Layer] 17 parts by mass of γ-glycidoxypropyltrimethoxysilane, 30 parts by mass of methanol, and 28 parts by mass of water-dispersed colloidal silica (solid content 40% by mass, average particle size 15 nm) were added to a glass container equipped with a magnetic stirrer and thoroughly mixed, followed by stirring for 24 hours at 5° C. Next, 15 parts by mass of propylene glycol monomethyl ether, 0.05 parts by mass of a silicone surfactant, and 1.5 parts by mass of aluminum acetylacetonate as a curing agent were added, thoroughly stirred, and then filtered to prepare Composition 1 for hard coat layer.

[0152] [Preparation of injection nozzle] A plate-shaped lens pedestal (made of polyoxymethylene, self-made) used to fix the lens substrate was placed in an oven in which the curing step was carried out, and one through-hole (injection nozzle) was provided in the plate-shaped lens pedestal so that an inert gas could be injected from the lens pedestal side at an injection angle of 90° with respect to the other surface of the lens substrate. That is, in the oven in which the curing step was carried out, the light source for irradiation, the lens, and the plate-shaped lens pedestal were arranged in this order from top to bottom. The light source for irradiation and the plate-shaped lens pedestal were arranged so that there was a distance of 300 mm between them.

[0153] [Production of Finished Lens] (Example 1) A lens substrate (EYNOA, S-8.00, manufactured by HOYA Corporation, central thickness 1.0 mm, peripheral thickness 9.1 mm) was immersed in a 10% by mass aqueous solution of sodium hydroxide (liquid temperature 60°C) for 5 minutes, then washed with pure water and dried. Primer layer composition 1 was then applied to the convex surface (object-side surface) of the lens substrate by spin coating in an environment of a temperature of 25°C and a relative humidity of 50%, and the lens substrate was then fixed to a plate-like lens base in a furnace where a curing step was performed. After fixing, nitrogen gas (5 in FIG. 1) was introduced into the furnace to create a nitrogen atmosphere (oxygen concentration: 500 volume ppm or less, introduction rate of nitrogen gas for maintaining the atmosphere: 7 times the volume of the furnace / min, temperature of the nitrogen atmosphere: room temperature). After the start of nitrogen gas injection, while continuously injecting nitrogen gas (6 in FIG. 1) (nitrogen gas injection rate: 1 time the volume of the furnace / min, nitrogen gas injection rate: 1.6 L / min, nitrogen gas injection angle: 90° with respect to the lens substrate, nitrogen gas temperature: room temperature), the primer layer composition 1 applied on the lens substrate was irradiated with light (continuous irradiation, light wavelength: 365 nm, light irradiation intensity: 165 mW / cm) using a UV lamp (metal halide). ２ , light irradiation time: 5 seconds, light irradiation exposure amount: 825 mJ / cm ２) and curing the composition to form a primer layer. The formed primer layer had a thickness of 8 μm. Photochromic layer composition 1 was applied onto the primer layer by spin coating. The spin coating was performed according to the method described in JP-A-2005-218994. Thereafter, the lens substrate was fixed to a plate-shaped lens base in a furnace where the curing step was carried out. After the fixation, nitrogen gas (5 in FIG. 1) was introduced into the furnace to create a nitrogen atmosphere (oxygen concentration: 500 volume ppm or less, introduction rate of nitrogen gas for maintaining the atmosphere: 7.0 times the volume of the furnace / min, temperature of the nitrogen atmosphere: room temperature), and after the start of nitrogen gas injection, while continuously injecting nitrogen gas (6 in FIG. 1) (injection rate of nitrogen gas: 1.0 times the volume of the furnace / min, injection rate of nitrogen gas: 1.6 L / min, injection angle of nitrogen gas: 90° with respect to the lens substrate, temperature of nitrogen gas: room temperature), the photochromic layer composition 1 was irradiated with light (continuous irradiation, light wavelength: 365 nm, light irradiation intensity: 165 mW / cm) using a UV lamp (metal halide). ２ , light irradiation time: 40 seconds, light irradiation exposure amount: 6600 mJ / cm ２ ), and the composition was cured to form a photochromic layer. The thickness of the formed photochromic layer was 45 μm. Protective layer composition 1 was applied onto the photochromic layer by spin coating to form a coating layer. The lens substrate was then fixed to a plate-shaped lens base in a furnace where a curing step was performed. After fixing, nitrogen gas (5 in FIG. 1 ) was introduced into the furnace to create a nitrogen atmosphere (oxygen concentration: 500 volume ppm or less, nitrogen gas introduction rate for maintaining the atmosphere: 7 times the volume of the furnace / min, nitrogen atmosphere temperature: room temperature). After the start of nitrogen gas injection, nitrogen gas (6 in FIG. 1 ) was continuously injected (nitrogen gas injection rate: 1 time the volume of the furnace / min, nitrogen gas injection rate: 1.6 L / min, nitrogen gas injection angle: 90° with respect to the lens substrate, nitrogen gas temperature: room temperature). The protective layer composition 1 was irradiated with light (continuous irradiation, light wavelength: 365 nm, light irradiation intensity: 165 mW / cm) using a UV lamp (metal halide). ２ , light irradiation time: 15 seconds, light irradiation exposure amount: 2475 mJ / cm ２) and curing the composition to form a protective layer. The thickness of the formed protective layer was 40 μm. After forming the three layers, the sample was heat-treated in a heat treatment device (PH series, manufactured by Espec Corporation) at an ambient temperature of 90°C for 2 hours to strengthen the adhesion of each cured coating layer. After the heat treatment, to prevent surface scratches, hard coat layer composition 1 was applied to the convex and concave surfaces by dip coating. Subsequently, a heat treatment device (PH series, manufactured by Espec Corporation) was used to perform a heat curing treatment at an ambient temperature of 100°C for 1 hour to form a hard coat layer. The thickness of the formed hard coat layer was 3.5 μm. The "thickness of the cured coating layer" was calculated by measuring the reflectance (interference waveform) of the sample using a non-contact film thickness measuring device (FF8 series, manufactured by System Road Co., Ltd.) and analyzing the film thickness value using FFT (fast Fourier transform). The "intensity of light irradiation" is a value measured using an actinometer (UIT-250, manufactured by USHIO Corporation) by lighting a lens base 300 mm away from the center of the light source to the light receiving unit (central wavelength 365 mm). The "amount of light irradiation exposure" is an integrated value of irradiation time (intensity of light irradiation (mW / cm)) measured using an actinometer (UIT-250, manufactured by USHIO Corporation) by lighting a lens base 300 mm away from the center of the light source to the light receiving unit (central wavelength 365 mm). ２ ) × irradiation time (seconds). The "injection amount" is the volume ratio of the furnace, measured by adjusting a needle valve using a small flow sensor (MF-F series, manufactured by Horiba, Ltd.). The "injection speed" is the value measured by adjusting a needle valve using a small flow sensor (MF-F series, manufactured by Horiba, Ltd.). The "amount of inert gas introduced for maintaining atmosphere" is the volume ratio of the furnace, measured by adjusting a needle valve using a small flow sensor (MF-F series, manufactured by Horiba, Ltd.). In this way, the finished lens of Example 1 was obtained.

[0154] (Example 2) The finished lens of Example 2 was obtained in the same manner as in Example 1, except that the injection rate of nitrogen gas when forming the primer layer was 2.0 times the volume of the furnace / min and the injection rate of nitrogen gas was 3.5 L / min, the injection rate of nitrogen gas when forming the photochromic layer was 2.0 times the volume of the furnace / min and the injection rate of nitrogen gas was 3.5 L / min, and the injection rate of nitrogen gas when forming the protective layer was 2.0 times the volume of the furnace / min and the injection rate of nitrogen gas was 3.5 L / min.

[0155] Example 3 A finished lens of Example 3 was obtained in the same manner as in Example 1, except that argon gas was used instead of nitrogen gas.

[0156] Comparative Example 1 A finished lens of Comparative Example 1 was obtained in the same manner as in Example 1, except that, as shown in FIG. 2, nitrogen gas (6 in FIG. 1) was not injected and no through-holes were provided.

[0157] (Comparative Example 2) The finished lens of Comparative Example 2 was obtained in the same manner as in Comparative Example 1, except that the plate-shaped lens base on which the lens substrate was placed was replaced with a trivet-shaped lens base (made of aluminum and self-made) as shown in Figure 3. By replacing the plate-shaped lens base with the trivet-shaped lens base, it is expected that a flow of nitrogen gas will occur on the other surface (concave surface) of the lens substrate, which did not occur in Comparative Example 1. (Comparative Example 3) The finished lens of Comparative Example 3 was obtained in the same manner as in Comparative Example 2, except that the rate of introduction of atmosphere-maintaining nitrogen gas when forming the primer layer was 27 times the volume of the furnace per minute, the rate of introduction of atmosphere-maintaining nitrogen gas when forming the photochromic layer was 27 times the volume of the furnace per minute, and the rate of introduction of atmosphere-maintaining nitrogen gas when forming the protective layer was 27 times the volume of the furnace per minute.

[0158] [Evaluation of Finished Lenses] The following evaluations were carried out using each of the obtained finished lenses. The evaluation results are shown in Table 1.

[0159] <Surface temperature of finished lens after light irradiation (surface temperature)> Using a radiation thermometer (TMHX-CNE0500 series, emissivity 0.95, manufactured by Japan Sensor Co., Ltd.), the surface temperature of the finished lens was observed in-line (within 2 seconds) after the UV curing process of each photocurable composition was completed. The smaller the measured surface temperature of the finished lens, the more suppressed thermal deformation.

[0160] <Adhesion> Evaluation was performed using a cross-cut tape test in accordance with JIS D 0202:2007. Specifically, using a utility knife, slits were made at approximately 1 mm intervals on the surface of the cured coating layer of each finished lens, forming 100 grids. Cellophane adhesive tape (Cellotape (registered trademark) manufactured by Nichiban Co., Ltd.) was firmly attached thereto, and then pulled in a 90° direction from the surface. After peeling, the number of grids where the coating layer remained was counted. The number of remaining grids and the number of grids before peeling were used to evaluate the adhesion according to the following criteria. [Evaluation criteria (number of remaining grids / number of grids before peeling)] A: 100 / 100 B: 95 / 100 or more but less than 100 / 100 C: 80 / 100 or more but less than 95 / 100 D: 50 / 100 or more but less than 80 / 100 E: Less than 50 / 100 Ratings A and B indicate excellent adhesion. On the other hand, in the cases of the ratings C, D and E, it cannot be said that the adhesion is excellent.

[0161] <Rear vertex power> In accordance with JIS T 7313:2020, the rear vertex power difference between both principal meridians due to the convex and concave surfaces of each finished lens was measured using a lens meter (CL-300, transmission type, manufactured by TOPCON CORPORATION). The rear vertex power difference of each finished lens was then compared with the rear vertex power difference of the lens substrate, and the difference in rear vertex power difference before and after the formation of the cured coating layer was calculated. The smaller the absolute value of the rear vertex power difference, the smaller the thermal deformation, and the larger the absolute value of the numerical value, the greater the thermal deformation. [Evaluation criteria (difference in rear vertex power difference)] A: Less than 0.07 B: 0.07 to 0.1 C: More than 0.1 In the cases of ratings A and B, it can be said that thermal deformation is sufficiently suppressed. On the other hand, in the case of rating C, it cannot be said that thermal deformation is suppressed.

[0162]

[0163] The results shown in Table 1 confirm that the finished lenses of Examples 1 to 3 did not require particularly complicated work or operations, and despite undergoing the same light irradiation as the finished lenses of Comparative Examples 1 to 3, the difference in surface vertex refractive power difference was smaller than that of the finished lenses of Comparative Examples 1 to 3, i.e., less thermal deformation. The results shown in Table 1 confirm that the finished lenses of Examples 1 to 3 have the same adhesion as the finished lenses of Comparative Examples 1 to 3, and it can be assumed that the curing of each photocurable composition has progressed sufficiently. The results for the finished lens of Example 1 and the finished lens of Comparative Example 2 (and the finished lens of Comparative Example 3) confirm that even if nitrogen gas flow is generated toward the other surface of the lens substrate, the effect of the present invention (suppression of thermal deformation) is not fully achieved compared to when an inert gas is sprayed. The inventors believe that spraying an inert gas toward the other surface of the lens substrate disperses the heat remaining on the other surface of the lens substrate, making it easier for the heat within the lens substrate to dissipate from the other surface of the lens substrate, resulting in less thermal deformation in the finished lenses of Examples 1 to 3.

[0164] Two or more of the various aspects and configurations described herein may be combined in any combination.

[0165] The embodiments disclosed herein should be considered to be illustrative in all respects and not restrictive. The scope of the present disclosure is defined by the claims, not the above description, and is intended to include all modifications within the meaning and scope of the claims.

[0166] The present disclosure is useful in the technical fields of eyeglasses, goggles, and the like.

[0167] REFERENCE SIGNS LIST 1 Lens substrate 2 Plate-shaped lens base 3 Trivet-shaped lens base 4 Through-hole 5 Nitrogen gas 1 6 Nitrogen gas 2

Claims

1. A method for producing a finished lens, comprising: a coating step of coating one surface of a lens substrate with a photocurable composition; a spraying step of spraying an inert gas toward the other surface of the lens substrate; and a curing step of curing the photocurable composition by light irradiation.

2. The method for manufacturing a finished lens according to claim 1, wherein the spraying step is carried out in a furnace in which the curing step is carried out, and the amount of the inert gas sprayed is 0.5 to 4.0 times the volume of the furnace per minute.

3. The method for manufacturing a finished lens according to claim 1 or 2, wherein the inert gas is sprayed at a rate of 0.8 to 7.0 L / min.

4. The method for manufacturing a finished lens according to claim 1 or 2, wherein said one surface is convex and said other surface is concave.

5. The method for manufacturing a finished lens according to claim 1 or 2, wherein the inert gas is at least one selected from the group consisting of nitrogen gas, argon gas, and carbon dioxide gas.

6. The method for producing a finished lens according to claim 1 or 2, wherein the photocurable composition is at least one selected from the group consisting of a polymerizable composition for forming a primer layer, a polymerizable composition for forming a photochromic layer, and a polymerizable composition for forming a protective layer.

7. A method for manufacturing a finished lens according to claim 1 or 2, wherein the lens substrate has a central portion having a thickness of less than 2 mm and a peripheral portion having a thickness greater than that of the central portion.

8. The method for manufacturing a finished lens according to claim 7, wherein an inert gas is injected into the central portion.

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