JP2008046264A - Optical article - Google Patents

Abstract

To provide an optical article having heat resistance and sufficient antireflection characteristics using a plastic substrate having a refractive index lower than 1.67 used in the field of lenses and the like, and a method for producing the same.
In an optical article, a two-layer organic antireflection layer is formed on a plastic substrate, the refractive index of the plastic substrate is 1.67 or less, and the organic antireflection layer is made of a plastic substrate. The refractive index of the layer located on the material side (high refractive index layer) is 1.6 to 2.0, and the refractive index of the layer located on the air side (low refractive index layer) is 1.3 to 1.5. is there.
[Selection figure] None

Description

  The present invention relates to an optical article used as a plastic spectacle lens or the like.

Plastic lenses are lighter in weight than glass lenses, have excellent moldability, processability, dyeability, etc., and are hard to break and have high safety. . In recent years, high refractive index materials such as thiourethane resins and episulfide resins have been developed in order to meet further demands for reduction in thickness and weight.
On the other hand, since a plastic lens is more easily damaged than a glass lens, generally, a hard coat layer is formed on the surface of a lens substrate to improve the surface hardness. In order to prevent surface reflection, an inorganic or organic antireflection layer is also formed on the upper surface of the hard coat layer. For example, an organic low-refractive-index antireflection layer having a refractive index lower by 0.10 or more than the lens base material is formed on a high-refractive index lens base material such as a thiourethane resin or a thioepoxy resin. A plastic lens excellent in antireflection characteristics has been proposed (see Patent Document 1).

JP 2003-222703 A

However, a lens substrate having a high refractive index as described in Patent Document 1 has a problem that heat resistance is low. In addition, the heat resistance tends to further decrease as the lens substrate has a higher refractive index.
On the other hand, a low refractive index lens base material having a refractive index lower than 1.67 is inexpensive and heat resistant, but has a small refractive index difference from the antireflection layer and does not provide sufficient antireflection characteristics.
Accordingly, an object of the present invention is to provide an optical article having sufficient antireflection characteristics using a plastic base material having a refractive index of 1.67 or less that is generally used in the field of lenses and the like. .

In order to solve the above-mentioned problems, the optical article of the present invention comprises a high refractive index layer located on the substrate side and a low refractive index layer located on the atmosphere side on a plastic substrate (hereinafter also simply referred to as “substrate”). An optical article in which an organic antireflection layer consisting of two layers with a refractive index layer is formed, wherein the refractive index of the substrate is 1.67 or less, and the two organic antireflection layers are The refractive index of the high refractive index layer is 0.1 or more higher than the refractive index of the low refractive index layer.
According to the present invention, the organic antireflection layer, which is usually one layer, is composed of two layers (a high refractive index layer and a low refractive index layer) as described above. That is, even if the base material itself has a low refractive index, by providing a high refractive index layer thereon, the difference in refractive index from the low refractive index layer provided thereon is sufficiently large to be 0.1 or more. By doing so, sufficient antireflection characteristics can be obtained. That is, sufficient antireflection characteristics can be obtained even if a low-refractive index base material with high versatility is used.
In addition, when this base material has the primer layer formed in the base-material surface, and the hard-coat layer formed in the upper surface of this primer layer, it is a concept also including them.

In the optical article described above, the antireflection effect is further improved by setting the refractive index difference between the high refractive index layer and the low refractive index layer to 0.1 to 0.7. Therefore, in this invention, it is preferable to set it as the layer structure whose refractive index of the said high refractive index layer is 1.6-2.0, and whose refractive index of the said low refractive index layer is 1.3-1.5.
In the present invention, the high refractive index layer is preferably formed from a coating composition containing metal oxide fine particles containing titanium oxide and an organosilicon compound.
Here, the organosilicon compound is, for example, a silane coupling agent represented by the following formula (1), and is easily transparent and strong by being hydrolyzed by an appropriate method and coated on a substrate. A resin layer is formed.
R ¹ R ² _n SiX ¹ _3-n (1)
(In the formula, R ¹ is an organic group having a polymerizable reactive group, R ² is a hydrocarbon group having 1 to 6 carbon atoms, X ¹ is a hydrolytic group, and n is 0 or 1. is there.)

According to this invention, the metal oxide fine particles containing titanium oxide are dispersed in the binder resin, and a high refractive index layer can be formed.
Further, the above-described titanium oxide is preferably a rutile type. Metal oxide particles containing titanium oxide having a rutile-type crystal structure are excellent in light resistance and have a higher refractive index than that of anatase-type titanium oxide, so the amount used in the high refractive index layer can be reduced. The amount of the resin component that contributes to adhesion can be increased.

In the present invention, the high refractive index layer is also preferably formed from a coating composition containing an organic titanium compound.
Here, the organic titanium compound is, for example, a titanium coupling agent, which is hydrolyzed by an appropriate method and coated on a base material to form a transparent and strong binder resin layer containing titanium oxide particles. .
Therefore, according to the present invention, it is possible to form a high refractive index layer only with an organic titanium compound without preparing metal oxide particles containing titanium oxide.

In the present invention, the low refractive index layer is preferably formed from a coating composition containing silica-based fine particles having internal cavities and an organosilicon compound.
Here, the organic silicon compound may be the same as the organic silicon compound (formula (1)) used for constituting the above-described high refractive index layer.
Further, as the organosilicon compound, a fluorine-containing compound as shown in the following formula (2) may be used.
^{_{X 2 m R 3 3-m}} Si-Y-SiR 3 3-m X 2 m (2)
(Wherein R ³ is a monovalent hydrocarbon group having 1 to 6 carbon atoms, Y is a divalent organic group containing one or more fluorine atoms, X ² is a hydrolyzable group, and m is an integer of 1 to 3). .)

According to this invention, since the silica-based fine particles having internal cavities are uniformly dispersed in a transparent and strong film formed from an organosilicon compound, a low refractive index layer having a sufficiently low refractive index can be formed. .
Further, when a fluorine-containing compound such as the above formula (2) is used, the low refractive index of the low refractive index layer can be further easily reduced due to the low refractive index inherent to the fluororesin. In addition, you may mix and use the compound of above-mentioned formula (1), and the compound of Formula (2).

  The above-described optical article can be suitably used as a plastic lens such as a spectacle lens, a camera lens, a telescope lens, a microscope lens, and a stepper condenser lens.

Hereinafter, embodiments of the optical article and the method for producing the optical article of the present invention will be described in detail. The optical article of this embodiment is a plastic lens for spectacles.
The plastic lens of this embodiment is composed of a plastic lens substrate and two organic antireflection layers. The primer layer is formed on the surface of the plastic lens substrate, and is formed on the upper surface of the primer layer. It is good also as a structure which has a hard-coat layer, the organic type antireflection layer which consists of two layers formed in the upper surface of this hard-coat layer, and an antifouling layer. Hereinafter, each of these layers will be described.

(1. Plastic lens substrate)
The material of the plastic lens substrate (hereinafter also referred to as “lens substrate”) is not particularly limited as long as the refractive index is 1.67 or less. Examples of such a lens material include diethylene glycol bisallyl carbonate (CR-39) and polycarbonate, or a polythiourethane type produced by reacting a compound having an isocyanate group or an isothiocyanate group with a compound having a mercapto group. Examples include plastic.

(2. Primer layer)
The primer layer is formed on the outermost surface of the lens substrate and is present at the interface between both the lens substrate and the hard coat layer described later, and has the property of exhibiting adhesion to both the lens substrate and the hard coat layer. It plays a role of improving the durability of the entire surface treatment film. Furthermore, it also has the property as an external shock absorbing layer and has the property of improving impact resistance.
Such a primer layer is preferably formed using a coating composition containing an organic resin polymer having polarity and metal oxide fine particles containing titanium oxide.

The organic resin polymer expresses adhesion to both the lens substrate and the hard coat layer. The metal oxide fine particles can act as a filler to improve the crosslinking density of the primer layer, thereby improving water resistance, weather resistance and light resistance. As the organic resin polymer, various resins such as a polyester resin, a polyurethane resin, an epoxy resin, a melamine resin, a polyolefin resin, a urethane acrylate resin, and an epoxy acrylate resin can be used. Among these, a polyester resin can be preferably used from the viewpoint of adhesion to a lens substrate containing a sulfur atom and dispersibility of metal oxide fine particles serving as a filler.
On the other hand, as the metal oxide fine particles containing titanium oxide, it is preferable to use a composite type containing titanium oxide having a rutile crystal structure from the viewpoint of light resistance. The average particle diameter of the metal oxide fine particles is preferably 1 to 200 nm, more preferably 5 to 30 nm.

In applying the coating composition (coating solution), the surface of the lens substrate is previously treated with an alkali treatment, acid treatment, surfactant treatment, inorganic or organic for the purpose of improving the adhesion between the lens substrate and the primer film. It is effective to perform peeling / polishing treatment with fine particles and plasma treatment. The coating composition is applied / cured by applying a coating composition by dipping, spin coating, spray coating, roll coating, flow coating, or the like, The primer layer can be formed by heating / drying at a temperature for several hours.
Moreover, the film thickness of a primer layer is 0.01-50 micrometers, Especially the range of 0.1-30 micrometers is preferable. If the primer layer is too thin, basic performance such as water resistance and impact resistance cannot be realized. Conversely, if the primer layer is too thick, the smoothness of the surface may be impaired, or appearance defects such as optical distortion, white turbidity, and cloudiness may occur. There is a case. In addition, in order to avoid generation | occurrence | production of an interference fringe, it is preferable to match | combine the refractive index of a primer layer with the refractive index of a lens base material.

(3. Hard coat layer)
The hard coat layer is formed on the primer layer formed on the lens substrate surface. The hard coat layer is preferably formed using a coating composition containing metal oxide fine particles containing titanium oxide and an organosilicon compound represented by the following formula (1).
R ¹ R ² _n SiX ¹ _3-n (1)
(In the formula, R ¹ is an organic group having a polymerizable reactive group, R ² is a hydrocarbon group having 1 to 6 carbon atoms, X ¹ is a hydrolytic group, and n is 0 or 1. is there.)

Titanium oxide preferably has a rutile crystal structure from the viewpoint of weather resistance and light resistance.
The organosilicon compound represented by the formula (1) is a so-called silane coupling agent and serves as a binder resin for the hard coat layer. In the formula (1), R1 is an organic group having a polymerizable reactive group and has 2 or more carbon atoms. R1 has a polymerizable reactive group such as vinyl group, allyl group, acrylic group, methacryl group, 1-methylvinyl group, epoxy group, mercapto group, cyano group, isocyano group, amino group and the like. X1 is a hydrolyzable functional group, and examples thereof include alkoxy groups such as methoxy group, ethoxy group, and methoxyethoxy group, halogen groups such as chloro group and bromo group, and acyloxy groups. R2 represents a monovalent hydrocarbon group having 1 to 6 carbon atoms, and specific examples thereof include alkyl groups such as methyl group, ethyl group, propyl group, butyl group, hexyl group, and cyclohexyl group, and phenyl group. can do. A methyl group is preferred for obtaining good scratch resistance.

  Examples of the organosilicon compound include vinyl trialkoxysilane, vinyltrichlorosilane, vinyltri (β-methoxy-ethoxy) silane, allyltrialkoxysilane, acryloxypropyltrialkoxysilane, methacryloxypropyltrialkoxysilane, and γ-glycid. Examples include xylpropyltrialkoxysilane, β- (3,4-epoxycyclohexyl) -ethyltrialkoxysilane, mercaptopropyltrialkoxysilane, γ-aminopropyltrialkoxysilane, and the like. Two or more of these “B component” organosilicon compounds may be used in combination.

  And when manufacturing the hard-coat liquid for forming a hard-coat layer, it is preferable to mix the sol in which the metal oxide microparticles | fine-particles were disperse | distributed, and an organosilicon compound. The compounding amount of the metal oxide fine particles is determined by the hardness and refractive index of the hard coat layer, and is 5 to 80% by mass, particularly 10 to 60% by mass, based on the solid content in the hard coat liquid. It is preferable. If the blending amount is too small, the wear resistance of the hard coat layer becomes insufficient, and if the blending amount is too large, cracks may occur in the hard coat layer. Moreover, when dyeing | hardening a hard-coat layer, dyeability may fall.

  In addition, it is very useful to contain a polyfunctional epoxy compound in the hard coat layer. The polyfunctional epoxy compound can improve the adhesion of the hard coat layer to the primer layer-and can improve the water resistance of the hard coat layer and the impact resistance as a plastic lens. Examples of the polyfunctional epoxy compound include aliphatic epoxy compounds such as 1,6-hexanediol diglycidyl ether and ethylene glycol diglycidyl ether, isophoronediol diglycidyl ether, and bis-2,2-hydroxycyclohexylpropane diglycidyl ether. And aromatic epoxy compounds such as resorcin diglycidyl ether, bisphenol A diglycidyl ether, and cresol novolac polyglycidyl ether.

  Further, a curing catalyst may be added to the hard coat layer. Examples of the curing catalyst include perchloric acids such as perchloric acid, ammonium perchlorate, and magnesium perchlorate, Cu (II), Zn (II), Co (II), Ni (II), and BE (II). CE (III), Ta (III), Ti (III), Mn (III), La (III), Cr (III), V (III), Co (III), FE (III), Al (III) Acetylacetonate having a central metal atom such as CE (IV), Zr (IV), V (IV), amino acids such as amine and glycine, Lewis acids, organic acid metal salts and the like.

  The coating composition (coating liquid) for forming a hard coat layer thus obtained can be diluted with a solvent and used as necessary. As the solvent, solvents such as alcohols, esters, ketones, ethers and aromatics are used. If necessary, light resistance of small amounts of metal chelate compounds, surfactants, antistatic agents, ultraviolet absorbers, antioxidants, disperse dyes, oil-soluble dyes, pigments, photochromic compounds, hindered amines, hindered phenols, etc. A heat stabilizer or the like can be added to improve the coating property, the curing speed, and the coating performance after curing.

  In addition, as a coating liquid application / curing method, a coating composition is applied by a dipping method, a spin coating method, a spray coating method, a roll coating method, or a flow coating method, and then at a temperature of 40 to 200 ° C. A hard coat film is formed by heating and drying for a period of time. In addition, it is preferable that the film thickness of a hard-coat layer is 0.05-30 micrometers. If the film thickness is less than 0.05 μm, the basic performance cannot be realized. On the other hand, if the film thickness exceeds 30 μm, the smoothness of the surface may be impaired or optical distortion may occur. The refractive index of the hard coat layer is preferably matched to the refractive indexes of the lens substrate and the primer layer in order to avoid generation of interference fringes.

(4. Organic antireflection layer)
The organic antireflection layer in the present embodiment is composed of two layers of organic thin films formed on the hard coat layer. This two-layer organic thin film is composed of a layer located on the lens substrate side (high refractive index layer) and a layer located on the atmosphere side (low refractive index layer). That is, the refractive index of the layer located on the lens substrate side is configured to be higher than the refractive index of the layer located on the atmosphere side.
Hereinafter, the high refractive index layer and the low refractive index layer in the present embodiment will be specifically described.

(4-1. High refractive index layer)
The high refractive index layer is preferably formed from a coating composition containing metal oxide fine particles containing titanium oxide and an organosilicon compound, or a coating composition containing an organotitanium compound.
Here, as the titanium oxide, for example, metal oxide fine particles having an average particle diameter of 1 to 200 nm including a composite oxide having a rutile type crystal structure composed of titanium oxide and tin oxide, or titanium oxide, tin oxide and silicon oxide. (Composite fine particles). By using metal oxide fine particles containing titanium oxide having a rutile-type crystal structure, weather resistance and light resistance are further improved. Moreover, since the metal oxide fine particles containing titanium oxide having a rutile type crystal structure have a higher refractive index than the anatase type, the amount used in the A layer can be reduced, contributing to adhesion. The amount of the resin component can be increased.

The type and blending amount of the metal oxide fine particles containing titanium oxide are determined by the target hardness, refractive index, etc., but the blending amount is 5% of the solid content in the coating composition for the high refractive index layer. It is desirable to be in the range of ˜80 mass%, particularly 10˜50 mass%. If the amount is too small, the abrasion resistance of the coating film may be insufficient. On the other hand, when there are too many compounding quantities, a crack will arise in a coating film and dyeing | staining property may become inadequate.
As the organosilicon compound, the organosilicon compound used in the hard coat layer is preferably used.

As the organic titanium compound, for example, a titanium coupling agent represented by the following formula (3) can be preferably used.
(R ⁴ O) _a TiR ⁵ _b R ⁶ _c (3)
(Where a + b + c = 4, a, b and c are integers selected from 0 to ⁴ , R ⁴ , R ⁵ and R ⁶ are hydrogen or a saturated or unsaturated hydrocarbon group, A functional group may be introduced into the hydrogen group.)
As the hydrocarbon group, those having 1 to 10 carbon atoms are preferred, and those having 1 to 6 carbon atoms are more preferred. Particularly preferably, for example, as R ⁴ , isopropoxyl and n-butoxy group can be exemplified, and R ⁵ and R ⁶ are acetonato having a vinyl group, an epoxy group, a methacryl group, an amino group, and a mercapto group, Aminato group can be raised.

  More specifically, tetraethoxy titanium, tetraisopropoxy titanium, tetra n-butoxy titanium, isopropoxy titanium triisostearate, isopropoxy titanium dimethacrylate isostearate, isopropoxy titanium tridodecyl benzene sulfonate, isopropoxy titanium tris. Dioctyl phosphate, isopropoxy titanium tri-N-ethylaminoethylaminato, titanium bisdioctyl pyrophosphate oxyacetate, bisdioctyl phosphate ethylene glycolato titanium, tetraisopropoxy titanium bisdioctyl phosphite, di-n-butoxybistriethanolaminato Examples include titanium. These titanium-based coupling agents may be two or more polycondensates produced by hydrolysis and dehydration condensation of some of the bonds. Two or more types may be used in combination or polycondensed.

(4-2. Low refractive index layer)
The low refractive index layer is preferably formed from a coating agent containing silica-based fine particles having internal cavities (hereinafter also referred to as “hollow silica-based fine particles”) and an organosilicon compound.
Here, the hollow silica-based fine particles are used because the internal cavity contains a gas or solvent having a refractive index lower than that of silica, so that the refractive index is reduced compared with silica-based fine particles without cavities. This is because a lower refractive index of the refractive index layer is achieved. Silica-based fine particles having internal cavities can be produced by the method described in JP-A-2001-233611, but in the present invention, the average particle diameter is in the range of 1 to 150 nm and the refractive index. Is preferably in the range of 1.16 to 1.39. When the average particle diameter of the particles is less than 1 nm, the void ratio inside the particles becomes small and a desired low refractive index cannot be obtained. On the other hand, when the average particle diameter exceeds 150 nm, the haze of the low refractive index layer increases, which is not preferable. A preferable average particle diameter can be calculated by the following formula.
Average particle size = (design wavelength (nm) / refractive index of organic antireflection layer) × 1/4
A dispersion sol containing hollow silica-based fine particles having an average particle diameter of 1 to 150 nm and a refractive index of 1.16 to 1.39 is commercially available (for example, manufactured by Catalytic Chemical Industry Co., Ltd., Thruria and Recum).

Further, as the organosilicon compound, the same organosilicon compound (formula (1)) used for constituting the above-described high refractive index layer may be used.
Further, as the organosilicon compound, a fluorine-containing compound as shown in the following formula (2) may be used.
^{_{X 2 m R 3 3-m}} Si-Y-SiR 3 3-m X 2 m (2)
(Wherein R ³ is a monovalent hydrocarbon group having 1 to 6 carbon atoms, Y is a divalent organic group containing one or more fluorine atoms, X ² is a hydrolyzable group, and m is an integer of 1 to 3). .)

Similarly to the organosilicon compound, the fluorine-containing compound represented by the formula (2) finally functions as a binder resin for the silica-based fine particles in the organic antireflection layer. In addition, when such a fluorine-containing compound is used, it is easier to lower the refractive index of the organic antireflection layer due to the low refractive index inherent in the fluorine-containing compound.
R ³ represents a monovalent hydrocarbon group having 1 to 6 carbon atoms, specifically, an alkyl group such as a methyl group, an ethyl group, a propyl group, a butyl group, a hexyl group, or a cyclohexyl group, a phenyl group, or the like. It can be illustrated. A methyl group is preferred for obtaining good scratch resistance. m is an integer of 1 to 3, preferably 2 or 3, and m = 3 is particularly preferable for a highly hard film. X represents a hydrolyzable group. Specific examples thereof include halogen atoms such as Cl, organooxy groups represented by OR _X (R _X is a monovalent hydrocarbon group having 1 to 6 carbon atoms), particularly methoxy group, ethoxy group, propoxy group, isopropoxy group, Examples include alkoxy groups such as butoxy groups, alkenoxy groups such as isopropenoxy groups, acyloxy groups such as acetoxy groups, ketoxime groups such as methylethyl ketoxime groups, and alkoxyalkoxy groups such as methoxyethoxy groups. Among these, an alkoxy group is preferable, and a silane compound having a methoxy group or an ethoxy group is particularly preferable because it is easy to handle and the reaction during hydrolysis is easily controlled.

In the formula (2), the number of fluorine atoms is preferably 4 to 50, particularly preferably 4 to 24. In order to develop various functions such as antireflection, antifouling, and water repellency, it is preferable to contain a large amount of fluorine atoms. In some cases, scratch resistance cannot be obtained. Accordingly, Y preferably has the following structure.
_{-CH 2 CH 2 (CF 2)} n CH 2 CH 2 -
_{-C 2 H 4 -CF (CF 3} ) - (CF 2) n -CF (CF 3) -C 2 H 4 -
N in the structural formula is preferably 2 to 20, more preferably 2 to 12, and particularly preferably 4 to 10. If it is less than this, various functions such as antireflection properties, antifouling properties, water repellency, and chemical resistance may not be obtained sufficiently, and if it is too much, the crosslinking density is lowered and sufficient scratch resistance is obtained. May not be obtained.

  In addition, in this coating composition, in order to improve the scratch resistance (wear resistance) of the organic antireflection layer, an epoxy group-containing organic compound containing one or more epoxy groups in the molecule may be included. preferable. Examples of such an epoxy group-containing organic compound include glycidoxymethyltrimethoxysilane, glycidoxymethyltriethoxysilane, α-glycidoxyethyltrimethoxysilane, α-glycidoxyethyltriethoxysilane, β -Glycidoxyethyltriethoxysilane, β-glycidoxypropyltrimethoxysilane, α-glycidoxypropyltrimethoxysilane, α-glycidoxypropyltriethoxysilane, β-glycidoxypropyltriethoxysilane, γ -Glycidoxypropyltrimethoxysilane, (3,4-epoxycyclohexyl) methyltrimethoxysilane, γ-glycidoxypropylvinyldiethoxysilane, γ-glycidoxypropylphenyldiethoxysilane, δ- (3,4 -Epoxycyclohexyl) butyltrie Toxisilane and the like can be mentioned.

  Moreover, you may use together resin, such as a silicone type, an acrylic type, an epoxy type, a urethane type, a melamine type, for the coating composition used for formation of a high refractive index layer or a low refractive index layer. Among these, in consideration of various properties such as heat resistance, chemical resistance, and scratch resistance as a plastic lens, it is preferable to include a silicone resin and an epoxy resin. In addition, for adjusting the refractive index, it is also possible to add particulate inorganic substances (metal oxide fine particles) and the like. Examples of the particulate inorganic substance to be added include colloidally dispersed sol. From the viewpoint of lowering the refractive index of the low refractive index layer, magnesium fluoride sol, calcium fluoride sol, and the like can be given.

  The coating composition for forming such a high refractive index layer or a low refractive index layer includes a small amount of a curing catalyst (a polymerization catalyst for producing a lens substrate), a photopolymerization initiator, and an acid generator as necessary. Agents, surfactants, antistatic agents, UV absorbers, antioxidants, light stabilizers such as hindered amines and hindered phenols, disperse dyes, oil-soluble dyes, fluorescent dyes, pigments, etc. The coating property after polymerization and curing can be improved.

The organic antireflection layer composed of the high refractive index layer and the low refractive index layer is suitably formed as an organic thin film having a predetermined refractive index on the hard coat layer by the wet method using the above-described coating composition. be able to.
As a method for forming the organic antireflection layer by a wet method, a known method such as a dipping method, a spinner method, a spray method, or a flow method can be used. Among these forming methods, the dipping method or the spinner method is preferable in consideration of uniformly forming a thin film having a film thickness of 50 to 150 nm on a curved surface like a plastic lens. In addition, when forming an organic type anti-reflective layer on a hard-coat layer, it is preferable to pre-process on the hard-coat layer surface. As a specific example of this pretreatment, a method of hydrophilizing the hard coat layer surface (contact angle θ = 60 ° or less) by surface polishing, ultraviolet-ozone cleaning, plasma treatment or the like is effective.

  The specific method of forming the organic antireflection layer is basically the same for the high refractive index layer and the low refractive index layer, and is performed by the following procedure. First, the organosilicon compound is diluted with an organic solvent, and then hydrolyzed by adding water, dilute hydrochloric acid, acetic acid or the like as necessary. Further, a system in which metal oxide fine particles or hollow silica fine particles are colloidally dispersed in an organic solvent is added. Thereafter, if necessary, a curing catalyst, a photopolymerization initiator, an acid generator, a surfactant, an ultraviolet absorber, an antioxidant, and the like are added, and after sufficiently stirring, used as a coating composition (coating liquid). In the case of using an organic titanium compound in the high refractive index layer, it is not necessary to add metal oxide fine particles.

  At this time, the concentration of the coating liquid diluted with respect to the solid content after curing is preferably 0.5 to 15% by mass, and more preferably 1 to 10% by mass as the solid content concentration. When the solid content concentration exceeds 15% by mass, it is difficult to obtain a predetermined film thickness even if the pulling speed is reduced by the dipping method or the rotation speed is increased by the spinner method. It becomes thicker than necessary. If the solid content is less than 0.5% by mass, the film thickness becomes thinner than necessary even if the pulling speed is increased by the dipping method or the rotation speed is decreased by the spinner method. It is difficult to obtain the film thickness. If the speed is too high or the rotational speed is too low, uneven coating on the lens tends to increase, and even when a surfactant or the like is added, the corresponding partition cannot be made.

  After the coating liquid is applied to the lens substrate, it is cured by heat or ultraviolet light and a combination thereof to obtain an organic antireflection layer, but it is preferably cured by heat treatment. The heating temperature in the heat treatment is determined in consideration of the composition of the coating liquid, the heat resistance of the lens substrate, and the like, but is preferably 50 to 200 ° C, more preferably 80 to 140 ° C.

A preferable value as the refractive index of the organic antireflection layer obtained by the above-described method is 1.6 to 2.0 as the refractive index of the high refractive index layer, and 1.3 to 2.0 as the refractive index of the low refractive index layer. 1.5. When the difference in refractive index between the two layers is smaller than 0.1, the antireflection effect is lowered. The refractive index difference between both layers is preferably 0.15 or more, more preferably 0.20 or more.
The thickness of the obtained organic antireflection layer is preferably in the range of 100 to 200 nm for the high refractive index layer and in the range of 100 to 200 nm for the low refractive index layer. If the film thickness is too thick or too thin than this range, a sufficient antireflection effect may not be obtained.

(5. Antifouling layer)
As described above, a plastic lens having a primer layer, a hard coat layer, and an organic antireflection layer formed on a lens base material has an antireflection film for the purpose of further improving the water and oil repellency of the plastic lens surface. An antifouling layer comprising an organosilicon compound containing fluorine can be formed thereon. As the organosilicon compound containing fluorine, for example, fluorine-containing silane compound compounds described in JP-A-2005-301208 and JP-A-2006-126782 can be suitably used.
The fluorine-containing silane compound can be applied on the organic antireflection layer using a water-repellent treatment solution dissolved in an organic solvent and adjusted to a predetermined concentration. As a coating method, a dipping method, a spin coating method, or the like can be used.
Although the film thickness of an antifouling layer is not specifically limited, 0.001-0.5 micrometer is preferable. More preferably, it is 0.001-0.03 micrometer. If the antifouling layer is too thin, the water and oil repellency effect will be poor, and if it is too thick, the surface will be sticky, which is not preferable. On the other hand, if the antifouling layer is thicker than 0.03 μm, the antireflection effect decreases, which is not preferable.

The plastic spectacle lens of the present embodiment as described above has a high refractive index layer having a refractive index of 1.6 to 2.0 and a refractive index of 1.3 to 1 from the lens substrate side as an organic antireflection layer. Therefore, even when a so-called low refractive index lens substrate having a refractive index of 1.67 or less is used, sufficient antireflection characteristics can be obtained. That is, sufficient antireflection characteristics can be obtained even if a low-refractive index base material with high versatility is used.
In addition, a spectacle lens having an excellent antireflection effect can be produced simply by forming a two-layered organic antireflection layer on the surface of the lens substrate by a wet method. It becomes unnecessary, and it becomes possible to reduce the manufacturing cost. Further, when providing a primer layer or a hard coat layer, the organic antireflection layer can be continuously formed by a wet method, so that no trouble is required in the production of spectacle lenses.
Furthermore, an inorganic antireflection layer formed by a dry method such as a vacuum deposition method or a sputtering method has low heat resistance due to a large thermal expansion coefficient difference from a hard coating layer made of a lower lens substrate or an organic coating. On the other hand, the organic antireflection layer formed by the wet method has a small difference in thermal expansion coefficient from the lens base material and the hard coat layer, so that cracking due to heating hardly occurs and has excellent heat resistance. A spectacle lens can be provided.

Next, examples and comparative examples based on the embodiment of the present invention will be described. Specifically, a plastic spectacle lens was manufactured by the method described below, and various evaluations such as reflectance and heat resistance were performed.
(Example 1)
(1) Plastic lens base material A thiourethane plastic lens base material (Seiko Super Sovereign Co., Ltd., Seiko Epson Corp., refractive index: 1.67) was prepared.

(2) Preparation of coating composition for high refractive index layer In a stainless steel container, 177.4 parts by mass of propylene glycol monomethyl ether was added, and 2.5 parts by mass of γ-glycidoxypropyltrimethoxysilane was added and stirred sufficiently. Thereafter, 1.2 parts by mass of a 0.1 mol / liter hydrochloric acid aqueous solution was added and stirring was continued for a whole day and night to obtain a silane hydrolyzate. To this silane hydrolyzate, 0.1 part by mass of a silicone surfactant (manufactured by Nippon Unicar Co., Ltd., trade name L-7001) was added and stirred for 1 hour, and then titanium oxide, tin oxide and silicon oxide were added. 18.0 parts by mass of a composite fine particle sol (rutile-type crystal structure, methanol dispersion, produced by Catalyst Kasei Kogyo Co., Ltd.) as a main component was added and mixed with stirring for 2 hours. Next, 0.6 parts by mass of an epoxy resin (manufactured by Nagase Kasei Co., Ltd., trade name EX-313) was added and stirred for 2 hours, and then 0.1 parts by mass of iron (III) acetylacetonate was added and stirred for 1 hour. Filtration was performed using a 2 μm filter to obtain a coating composition for a high refractive index layer.

(3) Preparation of coating composition for low refractive index layer 32.4 parts by mass of methanol was added to 47.8 parts by mass (0.08 mol) of the fluorinated silane compound represented by the following formula, and γ-glycidoxypropyltri 4.7 parts by mass (0.02 mol) of methoxysilane and 36 parts by mass of 0.1 mol / liter hydrochloric acid aqueous solution were added, and this was stirred and mixed to obtain a mixed solution. This mixed solution was stirred in a thermostatic bath at 25 ° C. for 2 hours to obtain a silicone resin having a solid concentration of 10% by mass.
_{(CH 3 O) 3 Si-} C 2 H 4 -C 6 F 12 -C 2 H 4 -Si (OCH 3) 3
This silicone resin and a hollow silica-isopropanol dispersion sol (manufactured by Catalyst Kasei Kogyo Co., Ltd., solid content concentration 20% by mass, average primary particle size 35 nm, outer shell thickness 8 nm) are obtained by the following formula. Then, 935 parts by mass of propylene glycol monomethyl ether was added and diluted to obtain a coating composition for a low refractive index layer having a solid content concentration of 3% by mass.

(4) Formation of organic antireflection layer The plastic lens substrate obtained in (1) above was treated with an alkali treatment (2 mol / liter potassium hydroxide aqueous solution kept at 50 ° C. for 5 minutes, then purified water) And then neutralized by immersing in 1.0 mol / liter sulfuric acid kept at 25 ° C. for 1 minute to carry out pure water washing, drying and cooling. The high refractive index layer coating composition prepared in (2) above was applied on one side by spin coating, baked at 120 ° C. for 20 minutes, spin-coated on the other side in the same manner, and baked at 120 ° C. for 10 minutes. did. Next, the coating composition for the low refractive index layer prepared in the above (3) was applied on one side by spin coating, baked at 120 ° C. for 20 minutes, then spin-coated on the remaining side in the same manner, and baked at 120 ° C. for 10 minutes. . Then, it heated for 2 hours in the oven maintained at 125 degreeC, and obtained the plastic lens in which the organic type antireflection layer which consists of a high refractive index layer and a low refractive index layer was formed. The formed organic antireflection layer had a high refractive index layer with a refractive index of 1.80, a film thickness of 150 nm, a low refractive index layer with a refractive index of 1.37, and a film thickness of 100 nm.

(Example 2)
In Example 2, a primer layer and a hard coat layer are formed on the upper surface of the lens substrate, and then an organic antireflection layer is formed in the same manner as in Example 1, and an antifouling layer is further formed thereon. It is.
(5) Preparation of primer layer coating composition In a stainless steel container, 3700 parts by mass of methyl alcohol, 250 parts by mass of pure water, and 1000 parts by mass of propylene glycol monomethyl ether were added and stirred sufficiently. Composite fine particle sol mainly composed of tin and silicon oxide (rutile-type crystal structure, methanol dispersion, total solid content concentration 20% by mass, manufactured by Catalyst Kasei Kogyo Co., Ltd., trade name OPTRAKE 1120Z (8RU-7 · G)) 2800 Part by mass was added and mixed with stirring. Next, after adding 2200 parts by mass of a polyester resin and stirring and mixing, 2 parts by mass of a silicone surfactant (manufactured by Nippon Unicar Co., Ltd., trade name L-7604) was added and stirring was continued for a whole day and night, followed by a 2 μm filter. Filtration was carried out to obtain a primer layer coating composition.

(6) Preparation of coating composition for hard coat layer Into a stainless steel container, 1000 parts by mass of butyl cellosolve was added, and 1200 parts by mass of γ-glycidoxypropyltrimethoxysilane was added and stirred sufficiently. 300 parts by mass of an aqueous liter hydrochloric acid solution was added and stirring was continued for a whole day and night to obtain a silane hydrolyzate. After adding 30 parts by mass of a silicone surfactant (trade name L-7001, manufactured by Nihon Unicar Co., Ltd.) to the silane hydrolyzate and stirring for 1 hour, the main component is titanium oxide, tin oxide, and silicon oxide. 7300 parts by mass of composite fine particle sol (rutile type crystal structure, methanol dispersion, manufactured by Catalyst Kasei Kogyo Co., Ltd., trade name OPTRAIQUE 1120Z (8RU-25 · A17)) was added and mixed with stirring for 2 hours. Next, 250 parts by mass of an epoxy resin (manufactured by Nagase Kasei Co., Ltd., trade name EX-313) was added and stirred for 2 hours, then 20 parts by mass of iron (III) acetylacetonate was added and stirred for 1 hour, and a 2 μm filter. Filtration was performed to obtain a coating composition for a hard coat layer.

(7) Preparation of antifouling layer coating composition Fluorine-containing silane compound (manufactured by Shin-Etsu Chemical Co., Ltd., blended with trade names KY-130 and KP-801 to have a solid content ratio of 80/20) A coating composition for an antifouling layer having a solid concentration of 0.3% by mass was prepared by diluting in fluorohexane.

(8) Formation of primer layer, hard coat layer, organic antireflection layer and antifouling layer The plastic lens substrate obtained in (1) above was subjected to alkali treatment (2 mol / liter of hydroxylation maintained at 50 ° C. After being immersed in an aqueous potassium solution for 5 minutes, washed with pure water, and then neutralized by immersion in 1.0 mol / liter sulfuric acid maintained at 25 ° C. for 1 minute), washed with pure water, dried, and released Cooled. And it immersed in the primer composition adjusted by said (5), dip-coated at a pulling-up speed of 200 mm / min, and baked at 80 degreeC for 20 minutes, and the primer layer was formed on the plastic substrate surface. Next, the plastic lens on which the primer layer is formed is dipped in the hard coat composition prepared in the above (6), dip-coated at a pulling rate of 400 mm / min, and baked at 80 ° C. for 30 minutes. A coat layer was formed. Then, it heated for 3 hours in the oven maintained at 125 degreeC, and obtained the plastic lens in which the primer layer and the hard-coat layer were formed. The formed primer layer had a thickness of 0.5 μm and a refractive index of 1.67, and the hard coat layer had a thickness of 2.3 μm and a refractive index of 1.67.

Next, the plastic lens on which the primer layer and the hard coat layer are formed is subjected to plasma treatment (atmospheric plasma), and then the high refractive index layer coating composition prepared in the above (2) is applied on one side by spin coating. After baking at 20 ° C. for 20 minutes, the remaining one surface was similarly spin-coated and baked at 120 ° C. for 10 minutes. Next, the coating composition for the low refractive index layer prepared in the above (3) was applied on one side by spin coating, baked at 120 ° C. for 20 minutes, then spin-coated on the remaining side in the same manner, and baked at 120 ° C. for 10 minutes. . Thereafter, heating is performed in an oven maintained at 125 ° C. for 2 hours to form an organic antireflection layer composed of a high refractive index layer and a low refractive index layer, and a primer layer, a hard coat layer, and an organic antireflection layer are formed. Obtained plastic lens. The formed organic antireflection layer had a high refractive index layer with a refractive index of 1.80, a film thickness of 150 nm, a low refractive index layer with a refractive index of 1.37, and a film thickness of 100 nm.
Subsequently, the plastic lens on which the primer layer, the hard coat layer and the organic antireflection layer are formed is dipped in the antifouling layer coating composition prepared in the above (5) and dip coated at a lifting speed of 150 mm / min. Baked at 60 ° C. for 10 minutes, and then put into a constant temperature and humidity chamber maintained at 90 ° C. and 90% relative humidity, held for 2 hours, and then heated in an oven maintained at 100 ° C. for 2 hours. A plastic lens having a primer layer, a hard coat layer, an organic antireflection layer and an antifouling layer was obtained.

(Example 3)
Implemented except that instead of Seiko Super Sovereign (refractive index: 1.67) as the lens base material, a thiourethane plastic lens base material (Seiko Super Lucious, refractive index 1.60) manufactured by Seiko Epson Corporation was used. A plastic lens was produced in the same manner as in Example 2.

Example 4
A plastic lens was produced in the same manner as in Example 2 except that a commercially available polycarbonate lens (refractive index: 1.59) was used instead of Seiko Super Sovereign (refractive index: 1.67) as the lens substrate.

(Example 5)
Instead of Seiko Super Sovereign (refractive index 1.67) as a lens substrate,
Example 2 except that a thiourethane-based plastic lens substrate (Seiko Epson Corporation Seiko SuperLucious, refractive index 1.60) was used and the coating composition for a high refractive index film was prepared according to the following procedure. Similarly, a plastic lens was manufactured.
In a nitrogen atmosphere, put 182.3 parts by mass of 1-butanol into a stainless steel container, add 13.7 parts by mass of tetrabutoxytitanium and sufficiently stir, and then add 2.5 parts by mass of 0.01 mol / liter hydrochloric acid aqueous solution. Was added and stirring was continued for a whole day and night to obtain a titanium hydrolyzate. In this titanium hydrolyzate, 0.1 part by mass of a silicone surfactant (manufactured by Nippon Unicar Co., Ltd., trade name L-7001) was added and stirred for 1 hour, and then an epoxy resin (manufactured by Nagase Kasei Co., Ltd.). , Trade name EX-313) After adding 0.6 parts by mass and stirring for 2 hours, the mixture was filtered with a 2 μm filter to obtain a coating composition for a high refractive index layer. The organic antireflection layer formed from this composition had a high refractive index layer with a refractive index of 1.85 and a film thickness of 148 nm.

(Example 6)
A plastic lens was produced in the same manner as in Example 5 except that a commercially available polycarbonate lens (refractive index 1.59) was used instead of Seiko Super Sovereign (refractive index 1.67) as the plastic lens substrate.

(Comparative Example 1)
A plastic lens was produced in the same manner as in Example 2 except that the primer layer, the hard coat layer, the low refractive index layer, and the antifouling layer were formed without forming the high refractive index layer.

(Comparative Example 2)
A plastic lens was manufactured in the same manner as in Example 3 except that the primer layer, the hard coat layer, the low refractive index layer, and the antifouling layer were formed without forming the high refractive index layer.

(Comparative Example 3)
A plastic lens was manufactured in the same manner as in Example 4 except that the primer layer, the hard coat layer, the low refractive index layer, and the antifouling layer were formed without forming the high refractive index layer.

(Evaluation methods)
The physical properties of the plastic lenses obtained in Examples 1 to 6 and Comparative Examples 1 to 3 were evaluated by the following methods. The evaluation items are nine items of reflectance, scratch resistance, initial adhesion, moisture resistance, warm water resistance, light resistance, alkali resistance, heat resistance and impact resistance.

(1) Reflectance The reflectance of the lens was measured using a spectrophotometer, and converted into the reflectance corrected for visibility according to the obtained visibility curve (average value in the wavelength range (380 to 780 nm)). 1 to 9 show the wavelength-reflectance curves of the plastic lenses obtained by the respective examples and comparative examples.

(2) Scratch resistance After applying steel wool # 0000 to the lens surface with a load of 1 kg and rubbing a distance of 3 to 4 cm for 10 reciprocations, the state of scratches that entered the lens surface with the eyes was visually evaluated as A to E below. Evaluation was made on the basis of 5 levels.
A: No scratches B: 1 to 5 scratches are confirmed C: 6 to 20 scratches are confirmed D: There are 21 or more scratches but it is not visible in cloudy E: Many Scratched and almost cloudy.

(3) Initial adhesion The surface of the lens is cross-cut into a base pattern at intervals of about 1 mm, and an adhesive tape (made by Nichiban Co., Ltd., trade name cello tape (registered trademark)) is firmly attached to the cross-cut portion. After attaching, the adhesive tape was peeled off rapidly, and the state of film peeling was evaluated on the basis of the base after the adhesive tape was peeled off according to the following five levels a to e.
a: No film peeling at all (number of film peeling eyes = 0/100)
b: Almost no film peeling (number of film peeling eyes = 1-5 / 100)
c: Some film peeling occurred (number of film peeling eyes = 6 to 20/100)
d: occurrence of film peeling (number of film peeling eyes = 21 to 50/100)
e: Adhesion failure (number of peeled films = 51 to 100/100)

(4) Moisture resistance The lens is left in a constant temperature and humidity oven (40 ° C., 90 RH%) for 10 days, and then the lens is taken out from the constant temperature and humidity oven and left at room temperature for 3 hours. went. The adhesion test was performed by the same method and the same evaluation criteria as (3) initial adhesion.

(5) Warm water resistance The lens was immersed in warm water at 80 ° C. for 2 hours, and then the lens was taken out from the warm water and cooled with water, and then an adhesion test was performed. The adhesion test was performed by the same method and the same evaluation criteria as (3) initial adhesion.

(6) Light resistance The lens was irradiated with a xenon long life weather meter (manufactured by Suga Test Instruments Co., Ltd.) for 200 hours. The lens was taken out of the xenon long life weather meter and cooled with water, and then an adhesion test was performed. . The adhesion test was performed by the same method and the same evaluation criteria as (3) initial adhesion.

(7) Alkali resistance The lens was immersed in an aqueous 10% by mass sodium hydroxide solution at 20 ° C. for 1 hour, and the lens was taken out and washed with water. The adhesion test was performed by the same method and the same evaluation criteria as (3) initial adhesion.

(8) Heat resistance The lens was glazed according to the shape of the spectacle frame, then fitted into the spectacle frame, completely tightened with screws, and placed in a constant temperature bath at 60 ° C. for 30 minutes. Thereafter, the lens was taken out, allowed to cool at room temperature for 1 hour, and then evaluated for occurrence of cracks. In the case where no cracks were generated, the presence or absence of cracks was evaluated after additional addition to a constant temperature bath at 65 ° C. for 30 minutes. Thereafter, the temperature was increased by 5 ° C., and the temperature was further increased for 30 minutes, and the temperature at which cracks occurred was defined as the heat resistant limit temperature.

(9) Impact resistance When a 16.3 g hard sphere was dropped vertically from the position of 127 cm onto the lens surface, it was evaluated as ◯ when it did not break, and x when broken or penetrated.

(Result)

From the results of Table 1, it can be seen that the spectacle lenses of Examples 1 to 6 all have a low reflectance of 0.6% in the visible region and an excellent antireflection effect. In particular, as in Examples 3 to 6, even for a heat-resistant lens base material, the refractive index of the base material itself is low, so that it is sufficient for spectacle lenses that have not been able to exhibit a sufficient antireflection effect so far. It is extremely important to provide a good antireflection characteristic. Moreover, in Examples 1-4, since the metal oxide fine particle containing the titanium oxide which has a rutile type crystal structure is used for formation of a high refractive index layer, especially light resistance is improving.
On the other hand, in Comparative Examples 1 to 3, since the organic antireflection layer is a single low refractive index layer, the refractive index difference from the lower layer cannot be increased, and thus the reflectance in the visible region is all 1 It is 0.0% or more and is inferior in the antireflection effect.

  The present invention can be applied without limitation as long as it is a plastic lens. Examples of the optical component include optical lenses such as a spectacle lens, a camera lens, a telescope lens, a microscope lens, and a stepper condenser lens.

FIG. 3 is a diagram showing the reflectance of a spectacle lens in Example 1. FIG. 6 is a diagram showing the reflectance of a spectacle lens in Example 2. FIG. 6 is a diagram showing the reflectance of a spectacle lens in Example 3. FIG. 6 is a diagram showing the reflectance of a spectacle lens in Example 4. FIG. 6 is a diagram showing the reflectance of a spectacle lens in Example 5. FIG. 10 is a diagram showing the reflectance of a spectacle lens in Example 6. The figure which shows the reflectance of the spectacles lens in the comparative example 1. The figure which shows the reflectance of the spectacles lens in the comparative example 2. FIG. The figure which shows the reflectance of the spectacles lens in the comparative example 3.

Claims (6)

An optical article in which an organic antireflection layer composed of two layers of a high refractive index layer located on the plastic substrate side and a low refractive index layer located on the atmosphere side is formed on the plastic substrate,
The plastic substrate has a refractive index of 1.67 or less,
The organic antireflection layer is an optical article, wherein a refractive index of the high refractive index layer is 0.1 or more higher than a refractive index of the low refractive index layer. The optical article according to claim 1.
The high refractive index layer has a refractive index of 1.6 to 2.0,
An optical article, wherein the low refractive index layer has a refractive index of 1.3 to 1.5. The optical article according to claim 1 or 2,
An optical article, wherein the high refractive index layer is formed of a coating composition containing metal oxide fine particles containing titanium oxide and an organosilicon compound. In the optical article according to any one of claims 1 to 3,
An optical article, wherein the high refractive index layer is formed from a coating composition containing an organic titanium compound. In the optical article according to any one of claims 1 to 4,
An optical article, wherein the low refractive index layer is formed of a coating composition containing silica-based fine particles having internal cavities and an organosilicon compound.   6. The optical article according to claim 1, wherein the optical article is a plastic lens.

Images