JPH0337161B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a synthetic resin lens in which a resin having a relatively high refractive index (refractive index 1.55 to 1.75) is provided as a synthetic resin, and a hard coat layer having a refractive index difference of ±0.04 with the resin is provided on the lens surface. In recent years, synthetic resins have come to be used as lens materials instead of conventional inorganic glasses. Compared to inorganic glass lenses, synthetic resin lenses have the characteristics of being lighter, have better impact resistance, and are easier to process, and are often used in safety-oriented eyeglass lenses, safety protection lenses, ski goggles, etc. It is being However, resins for lenses have the disadvantage that they are more easily scratched than glass, and for practical use as lenses, a hard coat is required to improve this disadvantage. There has been a lot of research on hard coats to improve the scratch resistance of synthetic resins, and patents include
7392, Special Publication No. 1959-19591, Special Publication No. 46-4641, Special Publication No. 47-26419, Special Publication No. 10137-1977, Special Publication No. 1977-
There are many reports such as 28445, Special Publication No. 52-36148, Special Publication No. 52-13536, Special Publication No. 13876 No. 53. On the other hand, when the refractive index of the lens substrate resin is ng and the refractive index of the hard coat layer is n, the reflected light R ₁ of the lens having the hard coat layer is given by the following equation. R ₁ = (n ² −ng/n ² +ng) ² ...(1) Therefore, assuming that the refractive index of the lens substrate resin and the hard coat layer are different and that the coat layer has a uniform thickness, Interference colors appear with reflective properties as shown. This interference color is expressed as the contrast Rmax - Rmin/Rmax, which is the difference between the maximum reflectance (Rmax) and the minimum reflectance (Rmin) divided by the maximum reflectance, and as shown in Figure 1, the contrast is , the larger the difference in refractive index between the hard coat layers. In addition, in the case of actual organic hard coats,
Paint films are often formed using the taping method, and it is difficult to maintain a uniform thickness of the paint film.Generally, a hard coat layer is formed that is thinner at the top and thicker at the bottom in the pulling direction. This is an important problem, especially in eyeglass lenses, where interference fringes appear as shown in Figure 2, degrading the lens properties and greatly deteriorating the appearance. The refractive index of the conventional hard coat mentioned above is around 1.5, so when coated on a lens substrate with a high refractive index, the contrast as shown in Figure 1 is large and the defects of the hard coat layer are small. Due to the uniformity, interference fringes as shown in FIG. 2 appear, which deteriorates the lens characteristics and spoils the lens appearance. The present invention focuses on this point and provides a hard coat synthetic resin lens that reduces interference due to reflection on the surface of a lens with a high refractive index. Specifically, the synthetic resin lens surface has a refractive index of 1.55 to 1.75, and the refractive index difference with the lens substrate resin is ±0.04.
This invention relates to a synthetic resin lens provided with a hard coat layer. When applying a hard coat to lens resin, the conditions for interference color to not damage the lens appearance are as follows: If the contrast of interference color is 20% or less, it is acceptable in terms of both lens performance and appearance. As a hard coat for lens resin having a refractive index of 1.55 to 1.75, it is sufficient if the difference in refractive index with the lens resin is within ±0.04. The hard coat layer having a refractive index of 1.55 to 1.75±0.04 is formed from a composition containing the following metal alkoxide as one component in order to increase the refractive index. 1 Etherified methylolmelamine, non-drying oil alkyd resin, metal alkoxide 2 Etherified methylolmelamine, OH group or
NR ₂ units or

[Formula] Group-containing acrylate or methacrylate resin, metal alkoxide 3 Etherified methylolmelamine, polycarboxylic acid, metal alkoxide 4 Etherified methylolmelamine, modified polyalkylene glycol, metal alkoxide 5 Etherified methylolmelamine, acid with double bond , metal alkoxide 6 Etherified methylolmelamine, a resin monomer containing two or more double bonds in the molecule and an OH group, metal alkoxide 7 Instead of the etherified methylolmelamine in 1 to 6 above, alkoxysilane Composition 8 in which a hydrolyzate of alkoxysilane is added to the compositions 1 to 6 above. Composition 9 in which a carbon functional polyorganosiloxane is used instead of the etherified methylolmelamine in 1 to 6 above. Composition 10 Added carbon functional polyorganosiloxane to the compositions 1 to 6 above Composition 11 Compositions obtained by removing the ether methylolmelamine from the compositions 1 to 6 above. In addition to these compositions, a polymerization initiator, condensation catalyst, and solvent are added, and the mixture is applied to the lens and cured.
A hard coat layer with a thickness of 0.5 to 50μ. Ether methylolmelamines include methoxymethylolmelamine, ethoxymethylolmelamine, ethoxymethylolmelamine, propoxymethylolmelamine, butoxymethylolmelamine, and the like. Examples of the acrylate or methacrylate containing OH group or NR ₂ group, CONR ₂ group include 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, 2-hydroxypropyl acrylate, 2-hydroxypropyl methacrylate,
Diethylene glycol monomethacrylate, triethylene glycol monoacrylate, triethylene glycol monomethacrylate, polyethylene glycol monoacrylate, polyethylene glycol monomethacrylate, 2-N,N-dimethylaminoethyl acrylate, 2-N,N-dimethylaminoethyl methacrylate, 2- N,N
-diethylaminoethyl acrylate, 2-N,
N-diethylaminoethyl methacrylate, 3-
N,N-diethylaminopropyl acrylate,
3-N,N-diethylaminopropyl methacrylate, N,N-dimethylacrylamide, N,N
-dimethylmethacrylamide, N,N-diethylacrylamide, N,N-diethylmethacrylamide, N,N-dibutylacrylamide, N,N
-Dibutyl methacrylamide, etc. Examples of polyhydric carboxylic acids include pyromellitic acid, trimellitic acid, phthalic acid, isophthalic acid, terephthalic acid, naphthalic acid, carphoric acid, and chelidonic acid. The modified polyalkylene glycol is represented by the general formula H-[-( _OR1 )mX] _-R1OH . _R1 ; _-CH2CH2 -,- _{CH2CH ( CH3} )--( _CH2 ) ₄ -x;

【formula】

【formula】

【formula】

[Formula] R ₂ ;-(CH ₂ ) ₁₀ ,

【formula】

【formula】

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【formula】

[Formula] Examples of acids having double bonds include acrylic acid, methacrylic acid, itaconic acid, maleic acid, and isophthalic acid. As a resin monomer that has two or more double bonds and an OH group in its molecule, etc. Hydrolysates of alkoxysilane include tetramethoxysilane, tetraethoxysilane, tetrapropoxysilane, tetrabutoxysilane, methyltrimethoxysilane, methyltriethoxysilane, methyltripropoxysilane, methyltributoxysilane, ethyltrimethoxysilane, Ethyltriethoxysilane, ethyltripropoxysilane, ethyltributoxysilane, propyltrimethoxysilane, propyltriethoxysilane, propyltripropoxysilane, propyltriptoxysilane, dimethyldimethoxysilane,
One or more hydrolysates of dimethyldiethoxysilane, dimethyldipropoxysilane, dimethylbutoxysilane, diethyldimethoxysilane, diethyldiethoxysilane, diethyldibutoxysilane, methylethyldimethoxysilane, methylpropyldiethoxysilane, etc. There are one type or a mixture of two or more types. Examples of the carbon functional polyorganosiloxane include 3,4-epoxycyclohexylalkyltrialkoxysilane, methacryloxyalkyltrialkoxysilane, vinyltrialkoxysilane, vinylcyclohexene dioxide, γ-glyoxyalkyltrialkoxysilane, and aminoalkyltrialkoxysilane. 1 of alkoxysilane etc.
A species or two or more species can be used. It is effective that the alkyl or alkoxy group has 1 to 6 carbon atoms. The general formula for metal alkoxides is M(OR ₁ ) _o or M(OR ₁ ) _n R _2o-n (where M is a metal atom, R ₁ and R ₂ are alkyl groups, m and n are integers, 0<m<n) is preferable, and preferable M examples include titanium (n=4) and zirconium (n
=4), hafnium (n=4), thorium (n=
4), vanadium monoxide (n=3), niobium (n=
5), tantalum (n=5), chromium (n=3), molybdenum (n=5), uranium (n=4), manganese (n=2), rhenium (n=3), iron (n=2 ,
3), lanthanum (n=3), cerium (n=4),
Tin (n=2), lead (n=2), zinc (n=2),
Aluminum (n=3) is mentioned. R ₁ is preferably a methyl group, ethyl group, propyl group, butyl group, or pentyl group. As R ₂ , a butoxy group, a 2-ethylhexoxy group, a stearyloxy group, an acetylacetone group, a triethanolamino group, and a lactate acid group are preferable. These metal alkoxides are used as monomers or one or more hydrolysates. The condensation catalyst is preferably one that cures at low temperature and in a short time, such as alkali thiocyanates, nitrates, carbonates, naphthenates, octylates, rosin salts of calcium, cobalt, iron, lead, manganese, zinc, etc. Examples include linseed oil fatty acid salts, P-toluenesulfonic acid, hydrochloric acid, and sulfuric acid. Generally, the refractive index of these hard coat layers increases by increasing the metal alkoxide content, and by adjusting the metal alkoxide content, a hard coat solution with a refractive index of 1.55 to 1.75 ± 0.04 can be created. adjust. After that, it is applied to the substrate resin by a dipping method, a spray method, or a spin method, and when it is cured by heating or ultraviolet irradiation, an organic hard coat consisting of a component containing a polymer in which a hydrolyzate of a metal alkoxide undergoes a condensation reaction is formed. A synthetic resin lens with high surface hardness and no interference color can be obtained. Examples of substrate resins with a refractive index of 1.55 to 1.75 include resins such as polycarbonate, polyhalogenated carbonate, polystyrene, epoxy resin, polysulfone, halogenated styrene, metal methacrylate, tripromophenyl methacrylate, phenyl methacrylate, benzyl methacrylate, and triaryl. Lucyanurate, diallyl phthalate, diallyl isophthalate, bisphenol A dimethacrylate, 2,2-bis(4-methacryloyloxyethoxyphenyl)propane, 2,2-bis(4
-methacryloyloxyedoxydibromophenyl)propane, 2,2-bis(4-methacryloyloxyethoxydichlorophenyl)propane,
One or more copolymers of 2,2-bis(4xmethacryloyloxyethoxydiiodophenyl)propane, phenoxyethyl acrylate, naphthalene dicarboxylic acid acrylic ester, or other polymers with the above monomers There are copolymers with monomers, etc. The present invention will be explained in detail below based on examples. Example 1 100 parts of 2-hydroxyethyl methacrylate and 0.5 parts of azobisisobutylnitrile (AIBN) are dissolved in 800 parts of ethyl cellosolve and polymerized at 60°C for 2 hours. To the solution are added 100 parts of methoxymethylolmelamine (Nikalac MS40) and 100 parts of a hydrolyzed quadruple of zirconium tetra-n-butoxy. A solution was prepared by adding 0.5 part of calcium naphthenic acid as a condensation catalyst. Example 2 70 parts of Bis-GMA, 30 parts of triethylene glycol methacrylate, and 0.1 part of AIBN are dissolved in 800 parts of ethyl celeryl and polymerized at 60°C for 1 hour. To the solution are added 50 parts of a hydrolyzed octamer of tetramethoxysilane and 100 parts of a hydrolyzed tetramer of lanthanum tri-i-propoxide. To this, 0.5 part of zinc naphthenate and 0.5 part of AIBN were added as condensation catalysts to prepare a solution. Example 3 70 parts of Bis-GMA, 30 parts of triethylene glycol methacrylate, and 0.1 part of AIBN are dissolved in 800 parts of ethyl cellosolve and polymerized at 60°C for 1 hour. 60 parts of hydrolyzed heptamer of tantalumbenta-n-butoxy are added to the solution. To this was added 0.5 part of calcium naphthenic acid as a condensation catalyst to prepare a solution. Example 4 γ-acryloxyethyltrimethoxysilane
100 parts, 100 parts of 2-hydroxyethyl methacrylate polymerized to a viscosity of 3P, 60 parts of zirconium tetra-n-butoxy tetramer, 0.5 parts of AIBN,
Calcium naphthenic acid 0.5 part, ethyl cellosolve
A solution consisting of 800 parts was prepared. Example 5 γ-acryloxyethyltrimethoxysilane
100 parts, 100 parts of 2-hydroxyethyl methacrylate polymerized to a viscosity of 3P, 100 parts of zirconium tetra-n-butoxy tetramer, AIBN0.5
1 part, 0.5 parts of calcium naphthenic acid, and 800 parts of ethyl cellosolve. Example 6 In place of the hydrolyzate of zirconium tetra-n-butoxy in Example 1, titanium tetra-n-
A decamer solution of butoxy hydrolyzate was prepared. Comparative Example 1 Methoxyethylolmelamine (Nikalatsuku)
MX40) 20 parts, tetramethoxysilane 60 parts, 2-
Hydroxyethyl methacrylate 3P 70
part, calcium naphthenic acid 0.5 part, AIBN 0.1 part,
A solution consisting of 800 parts of ethyl cellosolve was prepared. The solutions prepared in Examples 1 to 6 and Comparative Example 1 were applied to lens substrates having various refractive indexes by a dipping method and cured at 130°C for 60 minutes. (forming an organic hard coat layer consisting of a component containing the following), a hard coat lens was obtained. Table 1 shows the refractive index, scratch resistance, interference color appearance, and adhesion between the lens substrate and the hard coat of the obtained hard coat. The refractive index of the hard coat was calculated from equation (1) by measuring the reflection of visible light. Scratch resistance was evaluated by applying a load of 1 kg to #000 steel wool, rubbing it 20 times, and classifying the degree of scratching into 5 grades. The rough estimate is as follows. A: There is almost no damage. B: Slight damage. C: Diethylene glycol bisallyl carbonate (trade name CR-39) The resin was damaged. D: Damage level between C and E. E; polymethyl methacrylate, polystyrene,
It scratches just as easily as polycarbonate. The interference color was visually judged and evaluated by classifying it into three levels. A: No interference fringes are observed. B: Even faint interference fringes are observed. C: Rainbow-like interference fringes are clearly seen. Adhesion was determined by cross-cutting 100 stitches at 1mm intervals.
The sellotape was removed, and the number of stitches remaining in the coating film was measured out of 100 stitches. The lens substrate resin used in this example was as follows: 1; Polycarbonate 2; 60 parts of chlorostyrene, 2,2-bis-(4-
Copolymer 3 of 40 parts of methacryloyloxyethoxydibromophenyl)propane; 60 parts of chlorostyrene, 2,2-bis-(4-
30 parts of methacryloyloxyethoxydibromophenyl)propane, 2,2-bis[4-(3-
Copolymer of 10 parts of methacroxy-2-hydroxypropyl phenyl propane 4; Polylead dimethacrylate 5; KL1-1142 (trade name of Bayer AG)

【table】

[Table] As is clear from Table 1, according to the present invention, the refractive index of the hard coat layer can be adjusted according to the refractive index of the lens base material by adjusting the content of metal alkoxide. As a result, the difference in refractive index between the lens base material and the hard coat layer is reduced,
It has become possible to provide a high refractive index synthetic resin lens that has excellent optical performance with few interference fringes, as well as excellent impact resistance and scratch resistance.
This is highly effective in putting high refractive index synthetic resin lenses into practical use.

[Brief explanation of drawings]

Figure 1...For a substrate resin with a refractive index of 1.60
A diagram showing the reflection characteristics of a lens with a 0.6μ uniform hard coat layer. The refractive index of each hard coat layer is 1.
1.50, 2 is 1.56, 3 is 1.60, and 4 is 1.64. FIG. 2: A diagram showing how interference fringes appear on a lens in which a hard coat layer with a small refractive index is coated on a resin lens with a large refractive index by a doping method.

Claims (1)

[Claims] 1. On the surface of a synthetic resin lens having a refractive index of 55 to 1.75, the difference in refractive index with the synthetic resin lens is ±
1. A synthetic resin lens comprising an organic hard coat layer having a refractive index within 0.04 and comprising a component containing a polymer obtained by condensation reaction of a hydrolyzate of a metal alkoxide.