阅读说明：本技术 光学物品用涂布组合物、眼镜镜片、眼镜及眼镜镜片的制造方法、及光学物品及其制造方法 (Coating composition for optical article, spectacle lens, spectacle and method for producing spectacle lens, and optical article and method for producing same ) 是由 岛田拓哉 山下照夫 于 2020-03-27 设计创作，主要内容包括：本发明提供光学物品用涂布组合物,其包含光致变色化合物及2种以上的(甲基)丙烯酸酯,其中,上述2种以上的(甲基)丙烯酸酯包含分子量500以上的非环状的2官能甲基丙烯酸酯和非环状的3官能以上的(甲基)丙烯酸酯。(The present invention provides a coating composition for optical articles, comprising a photochromic compound and 2 or more kinds of (meth) acrylates, wherein the 2 or more kinds of (meth) acrylates comprise acyclic 2-functional methacrylate having a molecular weight of 500 or more and acyclic 3-functional or more (meth) acrylate.)

1. A coating composition for optical articles, comprising a photochromic compound and 2 or more (meth) acrylates,

the 2 or more (meth) acrylates comprise:

acyclic 2-functional methacrylate having a molecular weight of 500 or more, and

acyclic 3-or higher functional (meth) acrylates.

2. The coating composition for optical articles according to claim 1,

the 2 or more (meth) acrylates further comprise a 2-functional (meth) acrylate having a molecular weight of 400 or less.

3. The coating composition for optical articles according to claim 1 or 2,

the coating composition for optical articles comprises 50 mass% or more of the acyclic 2-functional methacrylate having a molecular weight of 500 or more with respect to the total amount of the 2 or more (meth) acrylates.

4. The coating composition for optical articles according to any one of claims 1 to 3, wherein,

the acyclic 2-functional methacrylate having a molecular weight of 500 or more has a molecular weight of 600 or more.

5. An eyeglass lens, comprising:

a lens base material, and

a photochromic layer obtained by curing the coating composition for optical articles according to any one of claims 1 to 4.

6. An eyeglass comprising the eyeglass lens according to claim 5.

7. An optical article, having:

a base material, and

a photochromic layer obtained by curing the coating composition for optical articles according to any one of claims 1 to 4.

8. The optical article according to claim 7, which is a lens for a goggles.

9. The optical article of claim 7, which is a visor portion of a sun visor cap.

10. The optical article of claim 7, which is a masking member of a helmet.

11. A method of manufacturing an optical article, the method comprising:

coating the coating composition for optical articles according to any one of claims 1 to 4 on a substrate; and

the photochromic layer is formed by curing the coated coating composition for an optical article.

12. The method of manufacturing an optical article according to claim 11,

the optical article is a spectacle lens.

13. The method of manufacturing an optical article according to claim 11,

the optical article is a lens for a goggles.

14. The method of manufacturing an optical article according to claim 11,

the optical article is a visor portion of the sun visor cap.

15. The method of manufacturing an optical article according to claim 11,

the optical article is a shield member of a helmet.

Technical Field

The present invention relates to a coating composition for optical articles, spectacle lenses, spectacles, and a method for producing spectacle lenses, and an optical article and a method for producing the same.

Background

The photochromic compound is a compound having a property (photochromic property) of developing a color when irradiated with light having a wavelength range of photoresponsiveness and fading a color when not irradiated. As a method for imparting photochromic properties to an optical article such as a spectacle lens, there is a method in which a coating layer containing a photochromic compound and a curable compound is provided on a base material, and the coating layer is cured to form a cured layer (photochromic layer) having photochromic properties (for example, see patent document 1).

Documents of the prior art

Patent document

Patent document 1: WO2003/011967

Disclosure of Invention

Problems to be solved by the invention

As a property desired for the optical article having photochromic properties as described above, there is a high color development density when it is developed by light irradiation.

One embodiment of the present invention provides a coating composition for an optical article, which can form a photochromic layer that can develop color at a high concentration.

Means for solving the problems

One embodiment of the present invention relates to a coating composition for optical articles (hereinafter also simply referred to as "composition") comprising a photochromic compound and 2 or more kinds of (meth) acrylates,

the 2 or more (meth) acrylates comprise:

acyclic 2-functional methacrylate having a molecular weight of 500 or more, and

acyclic 3-or higher functional (meth) acrylates.

The coating composition for optical articles contains, as the (meth) acrylate, an acyclic 2-functional methacrylate having a molecular weight of 500 or more and an acyclic 3-functional or more (meth) acrylate. Thus, in the photochromic layer formed by curing the composition, the photochromic compound irradiated with light can develop color at a high concentration.

ADVANTAGEOUS EFFECTS OF INVENTION

According to one embodiment of the present invention, a coating composition for an optical article can be provided which can form a photochromic layer that can develop color at high concentration when irradiated with light. In addition, according to one embodiment of the present invention, there can be provided a spectacle lens having a photochromic layer which can develop a color at a high concentration when irradiated with light.

Drawings

FIG. 1 shows the evaluation results of the color development concentrations of examples and comparative examples.

Fig. 2 shows the evaluation results of the photoresponsiveness (fading speed) of examples 1 and 2.

Detailed Description

[ coating composition for optical articles ]

A coating composition for an optical article according to one embodiment of the present invention includes a photochromic compound and 2 or more kinds of (meth) acrylates. These components will be described in further detail below.

[ meth (acrylic acid ester ]

In the present invention and the present specification, "(meth) acrylate" is used in a meaning including acrylate and methacrylate. "acrylate" refers to a compound having 1 or more acryloyl groups in 1 molecule. "methacrylate" refers to a compound having 1 or more methacryloyl groups in 1 molecule. In the present invention and the present specification, "methacrylate" refers to a compound containing only a methacryloyl group as a (meth) acryloyl group, and a compound containing both an acryloyl group and a methacryloyl group as a (meth) acryloyl group is referred to as an acrylate. The acryloyl group may contain an acryloyloxy group, and the methacryloyl group may contain a methacryloyloxy group. The following "(meth) acryloyl group" is used in the sense of including an acryloyl group and a methacryloyl group, and the following "(meth) acryloyloxy group" is used in the sense of including an acryloyloxy group and a methacryloyloxy group. The groups described may have a substituent or may be unsubstituted, unless otherwise specified. When a group has a substituent, examples of the substituent include an alkyl group (e.g., an 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, and a bromine atom), a cyano group, an amino group, a nitro group, an acyl group, and a carboxyl group. The "number of carbon atoms" of a group having a substituent means the number of carbon atoms of a moiety excluding the substituent.

The composition comprises more than 2 (methyl) acrylic esters. One of them is an acyclic 2-functional methacrylate having a molecular weight of 500 or more, and the other is an acyclic 3-functional or more (meth) acrylate. In the present invention and the present specification, "acyclic" means not including a cyclic structure. In contrast, "cyclic" means including a cyclic structure. The acyclic 2-functional methacrylate refers to a compound containing no cyclic structure and having 2 methacryloyl groups in 1 molecule. The acyclic 3-or more-functional (meth) acrylate refers to a compound containing no cyclic structure and having 3 or more (meth) acryloyl groups in 1 molecule. It is presumed that the reason why the photochromic layer formed from the composition can develop color at a high concentration when irradiated with light is that these compounds are contained.

(acyclic 2-functional methacrylate having a molecular weight of 500 or more)

The acyclic 2-functional methacrylate may be polyalkylene glycol dimethacrylate. The polyalkylene glycol dimethacrylate may be represented by the following formula 1.

[ chemical formula 1]

General formula 1

Wherein R represents an alkylene group, and n represents the number of repeating alkoxy groups represented by RO, and is 2 or more. Specific examples of the polyalkylene glycol dimethacrylate include polyethylene glycol dimethacrylate, polypropylene glycol dimethacrylate, polytetramethylene glycol dimethacrylate, and the like.

The molecular weight of the acyclic 2-functional methacrylate is 500 or more. The reason why the photochromic layer formed from the above composition can be colored at a high concentration by irradiation with light is presumed to be that it contains both an acyclic 2-functional methacrylate having a molecular weight of 500 or more and an acyclic 3-functional or more (meth) acrylate. In the present invention and the present specification, the molecular weight of the polymer is a theoretical molecular weight calculated from a structural formula determined by structural analysis of the compound or from a raw material charge ratio at the time of production. The molecular weight of the acyclic 2-functional methacrylate is 500 or more, preferably 510 or more, and more preferably 520 or more. From the viewpoint of forming a photochromic layer having excellent light responsiveness, the molecular weight of the acyclic 2-functional methacrylate is preferably 550 or more, more preferably 570 or more, further preferably 600 or more, still further preferably 630 or more, and still further preferably 650 or more. The molecular weight of the acyclic 2-functional methacrylate is preferably 2000 or less, 1500 or less, 1200 or less, 1000 or less, or 800 or less, for example, from the viewpoint of increasing the hardness of the photochromic layer.

(acyclic 3 or more functional (meth) acrylate)

The acyclic 3-or more-functional (meth) acrylate is preferably a 3-to 5-functional (meth) acrylate, more preferably a 3-or 4-functional (meth) acrylate, and still more preferably a 3-functional (meth) acrylate. Specific examples of the acyclic 3-or more-functional (meth) acrylate include pentaerythritol tri (meth) acrylate, pentaerythritol tetra (meth) acrylate, dipentaerythritol tetra (meth) acrylate, trimethylolethane tri (meth) acrylate, trimethylolpropane tri (meth) acrylate, ditrimethylolpropane tetra (meth) acrylate, tetramethylolmethane tri (meth) acrylate, and the like. The molecular weight of the acyclic 3-or higher-functional (meth) acrylate may be, for example, 200 to 400, but is not limited thereto. The acyclic 3-or higher-functional (meth) acrylate may contain only an acryloyl group, only a methacryloyl group, and both an acryloyl group and a methacryloyl group as the (meth) acryloyl group. In one embodiment, the acyclic 3-or more functional (meth) acrylate preferably contains only a methacryloyl group as the (meth) acryloyl group, i.e., is preferably a methacrylate.

(other (meth) acrylic acid esters)

The composition may contain 1 or 2 or more species of acyclic 2-functional methacrylate having a molecular weight of 500 or more and 1 or 2 or more species of acyclic 3-or more (meth) acrylate as the (meth) acrylate. The composition may contain one or more other (meth) acrylates in addition to these (meth) acrylates, or may contain no other (meth) acrylates. Other (meth) acrylates are useful, for example, for adjusting the viscosity of the composition. The other (meth) acrylate may be, for example, an acyclic or cyclic (meth) acrylate having 2 or more functional groups. The other (meth) acrylate may be a 2-5 functional (meth) acrylate, preferably a 2-4 functional (meth) acrylate, more preferably a 2-or 3-functional (meth) acrylate, and still more preferably a 2-functional (meth) acrylate. The molecular weight of the other (meth) acrylate may be, for example, 150 or more or 200 or more, or may be, for example, 400 or less or 350 or less, but is not limited to the above range.

In one embodiment, the other (meth) acrylate may be a non-cyclic 2-functional (meth) acrylate. Specific examples thereof include neopentyl glycol di (meth) acrylate, ethoxylated neopentyl glycol di (meth) acrylate, propoxylated neopentyl glycol di (meth) acrylate, 1, 6-hexanediol di (meth) acrylate, 1, 9-nonanediol di (meth) acrylate, 1, 10-decanediol diacrylate, ethylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, triethylene glycol di (meth) acrylate, tetraethylene glycol di (meth) acrylate, polyethylene glycol di (meth) acrylate, polypropylene glycol di (meth) acrylate, and the like. The molecular weight of the acyclic 2-functional (meth) acrylate is preferably 400 or less, more preferably 350 or less, and further preferably 150 or more, more preferably 200 or more.

The content of the acyclic 2-functional methacrylate having a molecular weight of 500 or more is preferably 50% by mass or more, more preferably 55% by mass or more, and even more preferably 60% by mass or more, assuming that the total amount of 2 or more (meth) acrylates contained in the composition is 100% by mass. The content of the acyclic 2-functional methacrylate having a molecular weight of 500 or more may be 80% by mass or less, or more than 80% by mass, for example. On the other hand, the content of the acyclic 3-functional or higher (meth) acrylate is preferably 5% by mass or higher, more preferably 7% by mass or higher, and still more preferably 10% by mass or higher, assuming that the total amount of 2 or more (meth) acrylates contained in the composition is 100% by mass. The content of the acyclic 3-or more-functional (meth) acrylate is preferably 20% by mass or less, and more preferably 15% by mass or less. The total content of the acyclic 2-functional methacrylate having a molecular weight of 500 or more and the acyclic 3-functional or more (meth) acrylate is preferably 55% by mass or more, more preferably 60% by mass or more, further preferably 65% by mass or more, and still further preferably 70% by mass or more, assuming that the total amount of 2 or more (meth) acrylates contained in the composition is 100% by mass. The total content of the acyclic 2-functional methacrylate having a molecular weight of 500 or more and the acyclic 3-functional or more (meth) acrylate may be 90% by mass or less, or 85% by mass or less, for example. On the other hand, when the total amount of 2 or more (meth) acrylic esters contained in the composition is 100% by mass, the content of other (meth) acrylic esters other than the acyclic 2-functional methacrylic ester and the acyclic 3-or more (meth) acrylic ester having a molecular weight of 500 or more may be 0% by mass or more and may be more than 0% by mass. When the total amount of 2 or more (meth) acrylic acid esters contained in the composition is defined as 100% by mass, the content of other (meth) acrylic acid esters in the composition is preferably 3% by mass or more, more preferably 5% by mass or more, still more preferably 7% by mass, and still more preferably 10% by mass or more. The content of the other (meth) acrylate is preferably 40% by mass or less, more preferably 35% by mass or less, and still more preferably 30% by mass or less. The composition may contain all (meth) acrylic acid esters at a content of, for example, 80 to 99.9 mass% with respect to 100 mass% of the total amount of the composition.

< photochromic Compound >

The composition contains 2 or more kinds of (methyl) acrylate and also contains photochromic compounds. As the photochromic compound contained in the composition, a known compound exhibiting photochromic properties can be used. The photochromic compound may exhibit photochromic properties to ultraviolet rays, for example. For example, as the photochromic compound, fulgimide (fulgimide) compound, spiroA compound having a known skeleton exhibiting photochromic properties, such as an oxazine compound, a chromene compound, and an indeno-fused naphthopyran compound. The photochromic compound may be used alone in 1 kind, or may be used in combination of 2 or more kinds. The content of the photochromic compound in the composition may be, for example, about 0.1 to 15% by mass, based on 100% by mass of the total composition, but is not limited to this range.

< optional ingredients >

Since the (meth) acrylate described above is a curable compound, the composition containing the (meth) acrylate can be a curable composition, and if subjected to a curing treatment, can be cured to form a cured layer. The above composition may contain a polymerization initiator for initiating a curing reaction (also referred to as polymerization reaction). As the polymerization initiator, a known polymerization initiator such as a photopolymerization initiator or a thermal polymerization initiator can be used depending on the kind of the curing reaction. The amount of the polymerization initiator to be used may be determined depending on the polymerization conditions, the type of the polymerization initiator, and the type of the curable compound contained in the curable composition.

The composition may further contain known additives which can be added to the composition containing a photochromic compound, and for example, additives such as a surfactant, an antioxidant, a radical scavenger, a light stabilizer, an ultraviolet absorber, an anti-coloring agent, an antistatic agent, a fluorescent dye, a pigment, a fragrance, a plasticizer, and a silane coupling agent may be added in an arbitrary amount. As these additives, known compounds can be used.

The above composition can be prepared by mixing the above-described respective ingredients simultaneously or sequentially in any order.

The composition is a coating composition for optical articles. The coating composition for optical articles is a composition to be coated on a substrate or the like for the production of optical articles. As the optical article, various lenses can be cited, and spectacle lenses can be preferably cited. The spectacle lens produced by applying the above composition to a lens base material can exhibit photochromic properties as a spectacle lens having a photochromic layer.

[ spectacle lens and method for producing spectacle lens ]

One embodiment of the present invention relates to a spectacle lens and a method for manufacturing the spectacle lens.

The eyeglass lens has: a lens base material and a photochromic layer obtained by curing the composition;

the method for manufacturing the spectacle lens comprises the following steps:

coating the composition on a lens substrate, and

the applied composition is subjected to a curing treatment to form a photochromic layer.

The spectacle lens and the method of manufacturing the spectacle lens will be described in further detail below.

< lens base >

The lens base material included in the above-mentioned spectacle lens may be a plastic lens base material or a glass lens base material. The glass lens substrate may be, for example, a lens substrate made of inorganic glass. As the lens base material, a plastic lens base material is preferable from the viewpoint of light weight, difficulty in breaking, and easiness in handling. Examples of the plastic lens base material include a styrene resin typified by a (meth) acrylic resin, a polycarbonate resin, an allyl carbonate resin such as an allyl resin and an allyl diglycol carbonate resin (CR-39), a vinyl resin, a polyester resin, a polyether resin, a polyurethane resin obtained by reacting an isocyanate compound with a hydroxyl compound such as diethylene glycol, a thiopolyurethane resin obtained by reacting an isocyanate compound with a polythiol, and a cured product (generally referred to as a transparent resin) obtained by curing a curable composition containing a (thio) epoxy compound having 1 or more disulfide bonds in the molecule. As the lens base material, an undyed lens base material (colorless lens) may be used, or a dyed lens base material (dyed lens) may be used. The refractive index of the lens base material may be, for example, about 1.60 to 1.75. However, the refractive index of the lens base is not limited to the above range, and may be within the above range or may be deviated from the above range in the up-down direction. In the present invention and the present specification, the refractive index refers to a refractive index for light having a wavelength of 500 nm. The lens base material may be a lens having a refractive power (so-called power lens) or a lens having no refractive power (so-called power lens).

The spectacle lens may be any of various lenses such as a single focus lens, a multi-focus lens, and a progressive power lens. The type of lens is determined by the shape of the two surfaces of the lens substrate. In addition, the surface of the lens base material may be any one of a convex surface, a concave surface, and a flat surface. In general, the lens base material and the spectacles have a convex object-side surface and a concave eyeball-side surface, but the present invention is not limited thereto. The photochromic layer is typically disposed on the object-side surface of the lens substrate, but may be disposed on the eyeball-side surface.

The photochromic layer formed using the above composition may be provided directly on the surface of the lens base material or indirectly via one or more other layers, and as the other layer, an undercoat layer for improving adhesion between the photochromic layer and the lens base material is exemplified, and such an undercoat layer is known.

< photochromic layer >

The photochromic layer of the spectacle lens may be formed by applying the composition directly or indirectly via one or more other layers on a lens substrate and curing the applied composition. As the coating method, a known coating method such as a spin coating method or a dip coating method can be used, and the spin coating method is preferable from the viewpoint of coating uniformity. The curing treatment may be light irradiation and/or heat treatment, and is preferably light irradiation from the viewpoint of allowing the curing reaction to proceed in a short time. The curing conditions may be determined depending on the kinds of the various components (the (meth) acrylate, the polymerization initiator, and the like described above) contained in the composition, and the composition of the composition. The thickness of the photochromic layer formed in this way is, for example, preferably in the range of 5 to 80 μm, and more preferably in the range of 20 to 60 μm.

The spectacle lens having the photochromic layer may have one or more functional layers in addition to the photochromic layer, or may not have a functional layer. Examples of the functional layer include layers known as functional layers for spectacles, such as hard coat layers, antireflection layers, hydrophobic or hydrophilic antifouling layers, and antifogging layers.

[ spectacles ]

One embodiment of the present invention relates to eyeglasses provided with the eyeglass lenses. The details of the spectacle lenses included in the spectacles are as described above. The above-mentioned spectacles have the above-mentioned spectacle lens, and for example, a photochromic compound contained in an outdoor photochromic layer develops color by irradiation of sunlight, whereby an antiglare effect like sunglasses can be exhibited, and the photochromic compound fades when returning to the indoor, and the transmittance can be restored. The above glasses can be applied to a known technique such as a structure of a frame.

[ optical article and method for producing optical article ]

One embodiment of the present invention relates to an optical article and a method for manufacturing the optical article.

The optical article has: a base material, and a photochromic layer obtained by curing the composition.

The method of manufacturing the optical article comprises the steps of:

applying the above composition to a substrate, and

the coated composition is subjected to a curing treatment to form a photochromic layer.

One embodiment of the optical article is the spectacle lens described above. In addition, as one embodiment of the optical article, a lens for a goggle, a visor portion of a sun visor cap, a shielding member of a helmet, and the like can be cited. An optical article having an antiglare function can be obtained by applying the composition to a substrate for such optical articles and curing the applied composition to form a photochromic layer.

Examples

The present invention will be further described with reference to examples. However, the present invention is not limited to the embodiments shown.

[ example 1]

< preparation of coating composition for optical article >

A (meth) acrylate mixture was prepared by mixing 68 mass% of polyethylene glycol dimethacrylate (molecular weight 736) (acyclic 2-functional methacrylate having a molecular weight of 500 or more; in the general formula 1, R represents ethylene and n ═ 14), 12 mass% of trimethylolpropane trimethacrylate (acyclic 3-functional (meth) acrylate), and 20 mass% of neopentyl glycol dimethacrylate (other (meth) acrylate) in a plastic container, based on 100 mass% of the total amount of the (meth) acrylate. To this (meth) acrylate mixture, a photochromic compound (an indeno-fused naphthopyran compound represented by the structural formula described in U.S. Pat. No. 5645767), a photopolymerization initiator (phenylbis (2, 4, 6-trimethylbenzoyl) phosphine oxide), an antioxidant (bis [3- (3-tert-butyl-4-hydroxy-5-methylphenyl) propionic acid ] [ ethylenebis (oxyethylene) ]), and a light stabilizer (bis (1, 2, 2, 6, 6-pentamethylpiperidinol) sebacate) were mixed and sufficiently stirred, and then a silane coupling agent (γ -methacryloxypropyltrimethoxysilane) was added dropwise with stirring. Then, defoaming was performed by an automatic revolution type stirring and defoaming device.

By the above method, coating compositions for optical articles having the compositions shown in table 1 below were prepared.

[ Table 1]

Composition (I)	Content ratio (% by mass)
		Acyclic 2-functional methacrylates having a molecular weight of 500 or more	58.97
Acyclic 3-functional (meth) acrylates	10.41
		Other (meth) acrylic esters	17.35
Photochromic compounds	2.60
		Photopolymerization initiator	0.26
Antioxidant agent	2.60
		Light stabilizers	2.60
Silane coupling agent	5.20

< production of spectacle lens >

A plastic lens base material (trade name EYAS manufactured by HOYA Co., Ltd.; center thickness 2.5mm, radius 75mm, S-4.00) was immersed in a 10 mass% aqueous solution of sodium hydroxide (liquid temperature 60 ℃ C.) for 5 minutes, and then washed and dried with pure water. Thereafter, a primer layer is formed on the convex surface (object side surface) of the plastic lens base material. Specifically, an aqueous urethane resin solution (polycarbonate polyol-based urethane emulsion; viscosity 100CPS, solid content concentration 38% by mass) was applied to the convex surface of a plastic lens base material by a spin coating method in an environment of 25 ℃ and 50% relative humidity, and then dried naturally for 15 minutes to form a primer layer having a thickness of 5.5 μm.

The composition prepared above was applied on the undercoat layer by spin coating. The spin coating method is carried out by the method described in Japanese patent laid-open No. 2005-218994. Then, the composition applied to the plastic substrate was irradiated with ultraviolet rays (wavelength: 405nm) in a nitrogen atmosphere (oxygen concentration: 500ppm or less) to cure the composition, thereby forming a photochromic layer. The photochromic layer was formed to have a thickness of 45 μm.

In the examples and comparative examples, the degree of progress of the curing reaction of the plurality of photochromic layers was changed by changing the light irradiation time.

[ example 2]

An eyeglass lens having a photochromic layer was produced in the same manner as in example 1, except that the acyclic 2-functional methacrylate having a molecular weight of 500 or more was changed to polyethylene glycol dimethacrylate (molecular weight 536; in the above formula 1, R is ethylene and n is 9).

Comparative example 1

A spectacle lens having a photochromic layer was produced in the same manner as in example 1, except that polyethylene glycol diacrylate (molecular weight 508) was used instead of the acyclic 2-functional methacrylate having a molecular weight of 500 or more.

Comparative example 2

A spectacle lens having a photochromic layer was produced in the same manner as in example 1, except that polyethylene glycol diacrylate (molecular weight 708) was used instead of the acyclic 2-functional methacrylate having a molecular weight of 500 or more.

[ evaluation method ]

< color development concentration >

Evaluation of photochromic properties was carried out by the following method in accordance with JIS T7333: 2005.

The photochromic layer of each of the spectacle lenses of examples and comparative examples was irradiated with light for 15 minutes (900 seconds) from a xenon lamp through a gas filter onto the surface of the photochromic layer, thereby developing the photochromic compound in the photochromic layer. The transmittance at the time of the color development (measurement wavelength: 550nm) was measured by a spectrophotometer manufactured by Otsuka electronics Co., Ltd. The light irradiation was performed in accordance with JIS T7333:2005 so that the irradiation illuminance and the allowable difference between the irradiation illuminances were values shown in table 2 below.

[ Table 2]

Wavelength region (nm)	Irradiance (W/m)2)	Allowable difference of radiation illuminance (W/m)2)
			300～340	＜2.5	-
340～380	5.6	±1.5
			380～420	12	±3.0
420～460	12	±3.0
			460～500	26	±2.6

The smaller the value of the transmittance measured above, the more highly concentrated the photochromic compound develops.

Fig. 1 shows a graph in which the transmittance obtained as described above is plotted against the light irradiation time when the photochromic layer is formed as a result of evaluation of the color development concentration.

From the results shown in fig. 1, it was confirmed that the spectacle lenses of examples 1 and 2 are superior to those of comparative examples 1 and 2 in terms of color development density.

< photoresponsiveness (fading speed) >

The spectacle lenses of examples 1 and 2 were evaluated for light responsiveness (fading speed) by the following method.

The transmittance (measurement wavelength: 550nm) before light irradiation (in an undeveloped state) of each of the spectacle lenses of examples and comparative examples was measured by a spectrophotometer manufactured by Otsuka electronics Co., Ltd. The transmittance measured here is referred to as "initial transmittance".

The photochromic layer of each of the spectacle lenses of examples and comparative examples was irradiated with light via a xenon lamp through a gas filter for 15 minutes (900 seconds) to develop the photochromic compound in the photochromic layer, and the transmittance at the time of development was measured in the same manner as described above.

Then, the time (half-life) required from the time when the light irradiation was stopped to the time when the transmittance was [ (initial transmittance-transmittance at the time of color development)/2 ] was measured. The smaller the value of the half-life measured in this manner, the higher the fading speed and the more excellent the light responsiveness.

Fig. 2 shows a graph in which the half-life determined above is plotted against the light irradiation time when the photochromic layer is formed as a result of evaluation of the light responsiveness (fading speed). From the results shown in fig. 2, it was confirmed that the optical responsiveness of the spectacle lens of example 1 was superior to that of the spectacle lens of example 2. It is presumed that the difference in the photoresponsiveness is caused by the difference in the molecular weights of the acyclic 2-functional methacrylate for forming the photochromic layer in example 1 and example 2.

Finally, the above-described modes are summarized.

According to one embodiment, there is provided a coating composition for optical articles, comprising a photochromic compound and 2 or more types of (meth) acrylates, wherein the 2 or more types of (meth) acrylates comprise an acyclic 2-functional methacrylate having a molecular weight of 500 or more and an acyclic 3-functional or more (meth) acrylate.

According to the coating composition for optical articles, a photochromic layer capable of developing color at a high concentration can be formed.

In one embodiment, the 2 or more kinds of (meth) acrylates may further include an acyclic 2-functional (meth) acrylate having a molecular weight of 400 or less.

In one embodiment, the coating composition for optical articles may contain 50 mass% or more of the acyclic 2-functional methacrylate having a molecular weight of 500 or more with respect to the total amount of the 2 or more (meth) acrylates.

In one embodiment, the 2-functional methacrylate having a molecular weight of 500 or more has a molecular weight of 600 or more.

According to one embodiment, there is provided an eyeglass lens comprising a lens base material and a photochromic layer obtained by curing the composition.

The spectacle lens can have a photoluminescent layer which is excellent in light responsiveness and can develop color at a high concentration.

According to one aspect, there is provided eyeglasses including the eyeglass lens.

According to one embodiment, there is provided an optical article comprising a base material and a photochromic layer obtained by curing the composition.

According to one aspect, there may be provided a method of manufacturing an optical article, the method comprising: the composition is applied to a substrate, and the applied composition is cured to form a photochromic layer.

According to the above manufacturing method, an optical article having an antiglare function can be provided.

In one embodiment, the optical article may be a spectacle lens, a lens for a goggle, a visor portion of a sun visor, a shield member of a helmet, or the like.

The various embodiments described in the present specification can combine 2 or more kinds in arbitrary combinations.

The embodiments disclosed herein are to be considered in all respects as illustrative and not restrictive. The scope of the present invention is intended to include all modifications not described above but shown in the claims, which are equivalent in meaning and scope to the claims.

Industrial applicability

The present invention is useful in the technical fields of eyeglasses, goggles, sun visors, helmets, and the like.