JPS61115915A - Plastic lens material - Google Patents

Abstract

PURPOSE:The titled material having a high transmittance to visible light, a high refractive index and being excellent in scratch resistance, solvent resistance, etc., prepared by copolymerizing a biphenyl (meth)acrylate monomer with a monomer containing a plurality of (meth)allyl groups. CONSTITUTION:A plastic lens material is prepared by copolymerizing a monomer of formula I (wherein R1 is H or CH3, R2 is a group of formula II and n is 0-2), e.g., o-biphenyl (meth)acrylate, with a monomer containing at least two (meth)allyl groups in the molecule (e.g., diethylene glycol bisallyl carbonate). This lens material has a visible light transmittance >=88% and a refractive index as high as 1.55 or above and can well meet various properties necessary for a spectacle lens, such as scratch resistance, solvent resistance and grindability with diamond wheels.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a plastic lens material,
More specifically, the present invention relates to a three-dimensionally crosslinked high refractive index plastic lens material.

[Conventional technology]

Plastic lenses are becoming widely used in optical products due to their ease of molding and light weight. Particularly in the case of eyeglass lenses, the weight of the entire eyeglass has a large effect on both the physiology and the optics of the eyeglass, so it is desirable that the lens be light. For this reason, the resin that has become the mainstream for plastic eyeglass lenses in recent years is 0R, which is made of polydiethylene glycol bisallyl carbonate.
-39 (manufactured by PPG, trade name), and can reduce the weight of the lens to 1/2 that of inorganic glass. However, since the refractive index of CR-39 is 1.49 to 1.50,
Compared to inorganic glass, CR-39 tends to have larger center thickness, edge thickness, and curvature, so a plastic lens with a high refractive index that solves these problems is desired. As a resin with a high refractive index, polycarbonate (D = 1.58),
There is polystyrene (D = 1.60). These are linear polymers, and because they are all thermoplastic, they cannot be cast and molded, making them unsuitable for producing a wide variety of products such as eyeglass lenses. Furthermore, thermoplastic lenses have defects such as the fact that post-processing with a diamond grindstone is not possible, the surface hardness is insufficient and the surface is easily scratched, the lens is easily affected by organic solvents, and the heat resistance is poor. Because of this, its scope of use is actually limited to some areas.

To provide a three-dimensionally crosslinked high refractive index plastic lens material, (I) a method using di(meth)acrylate derived from bisphenol A as the main component (Japanese Patent Publication No. 17527/1982), (2) halogen A method using di(meth)acrylate derived from bisphenol A as the main component (JP 57-104901), (3
) A method of using a halogenated styrene monomer in combination with a polyfunctional methacrylate (JP-A-57-104101, JP-A-57-28118, JP-A-57-28116),
(4) Method using diallyl 7-thalerate monomer (JP-A-57-212401, JP-A-58-15513)
etc. have been proposed.

[Problem that the invention seeks to solve]

・However, with method (I), it is difficult to obtain a three-dimensional crosslinked plastic with a refractive index of 1.55 or more;
Although the methods of ) and (3) result in a three-dimensionally crosslinked plastic having a high refractive index of 1.60 or more, there are problems with the coloring and weather resistance of the plastic. Furthermore, the method (4) also has the problem of coloring and, in addition, has the disadvantage of poor transmittance.

An object of the present invention is to provide a three-dimensionally crosslinked high refractive index plastic lens material that solves the above-mentioned problems.

[Means for solving problems]

That is, the gist of the present invention is the general formula (I) (wherein R1 is hydrogen or a methyl group, R1 is +CH-CH2O+n, and n represents an integer from O to 2).
A mixture consisting of a monomer (A) represented by the formula and a monomer (B) having at least two (meth)allyl groups in one molecule is copolymerized, and the refractive index is 1.55. This is a plastic lens material characterized by the above.

Specific examples of the monomer represented by the general formula (I) of the present invention include orthobiphenyl methacrylate, orthobiphenyl acrylate, 2-orthobiphenylethyl methacrylate, 2-orthobiphenylethyl acrylate, and 2-orthobiphenyl bromine. Bill methacrylate,
Examples include 2-orthobiphenylethyl acrylate. Among them, orthobiphenyl methacrylate is particularly cited as one that can provide a lens material with a high refractive index and good transparency.

Specific examples of the monomer (B) having at least two (meth)allyl groups in one molecule, which is the second component of the present invention, include ethylene glycol diallyl ether, ethylene glycol diallyl ether, diethylene glycol diallyl ether, Diethylene glycol cymetallyl ether/I/.

Trimethylolpropane triallyl ether.

Trimethylolpropane trimethallyl ether.

Diethylene glycol bisallyl carbonate.

Examples include diethylene glycol bismethallyl carbonate, diallyl adipate, dimethallyl adipate, diallyl phthalate, etc. Among them, diethylene glycol bisallyl carbonate is particularly resistant to solvents.

This is preferred in order to provide a lens material with good processability, impact resistance, and dyeability.

When carrying out the present invention, 30 to 95% by weight of the monomer (A) represented by the general formula (I) in the mixture with the monomer (B)
It is preferable to use the range. Monomer (A)
If the content is less than 30% by weight, the refractive index of the obtained lens will be too low, which is not preferable. Further, when the content of the monomer (A) is 95% by weight or more, the impact resistance of the lens obtained is lowered.

This is not preferred because processability and solvent resistance are extremely deteriorated.

Further, the radical polymerization initiator used in the copolymerization to obtain the lens resin of the present invention is not particularly limited, and may be a known benzoyl peroxide.

Peroxides such as p-chlorobenzoyl peroxide, diisopropyl peroxycarbonate, di-2-ethylhexyl peroxycarbonate, and tert-butyl peroxybivalate can be used in an amount of 0.1 to 5% by weight. , [Examples] Hereinafter, the present invention will be specifically explained based on Examples. In the examples, "parts" means parts by weight.

Example 1 A mixture consisting of 75 parts of orthobiphenyl methacrylate, 25 parts of diethylene glycol bisallyl carbon, t--), 2.5 parts of diisopropyl peroxycarbonate, and 0.5 parts of benzoyl peroxide was mixed with glass for molding a lens having a diameter of 65 m. The mixture was poured into a mold made of polyethylene gasket and kept in a hot air oven at 50°C for 24 hours. After further holding at 95°C for 4 hours, the polymer was taken out from the mold and examined for refractive index, hardness, and impact resistance.

Solvent resistance, processability, and visible light transmittance were measured.

The results are shown in Table 1, and the lens was colorless and transparent, had a pencil hardness of 4H1, and a refractive index of 1.605°C. The refractive index is measured using an Atsube refractometer, and the pencil hardness is J.
IS (K5400)K was therefore measured.

Other physical properties were measured by the methods described below.

Impact Resistance: Lenses with a center wall thickness of 2 were tested according to FDA standards.

Solvent resistance: methanol, acetone lens.

Soaked in benzene for 7 days at room temperature However, in both solvents, If there is no clouding on the surface, it is considered to be passed. did.

Workability: Lenses were processed using an eyeglass lens polishing machine, and those with no chipped edges and a smooth cut surface were considered acceptable.

Examples 2 to 3, Comparative Examples 1 to 5 Lenses of various compositions were created using the same method as in Example 1, and the results are summarized in Table 1 as Examples and Comparative Examples.

〔Effect of the invention〕

As is clear from Table 1, the plastic lens material of the present invention is significantly superior to the conventional products shown in the comparative examples in many performances required for eyeglass lenses.

The plastic lens material of the present invention has a visible light transmittance of 8.
We produce plastic lenses that have a high refractive index of 8% or more and a refractive index of 1.55 or more, and that fully satisfy the various properties required of eyeglass lenses, such as scratch resistance, solvent resistance, and diamond grindability. The industrial value is extremely large.

Claims (1)

[Claims] 1. General formula (I) ▲There are mathematical formulas, chemical formulas, tables, etc.▼(I) (However, in the formula, R_1 is hydrogen or a methyl group, and R_2 is ▲
There are mathematical formulas, chemical formulas, tables, etc. ▼, n is an integer from 0 to 2) Monomer (A) represented by ), and has a refractive index of 1.55 or more. 2. The plastic lens material according to claim 1, characterized in that a mixture containing the monomer (A) is 30 to 95% by weight. 3. The plastic lens material according to claim 1, wherein the monomer (A) is orthobiphenyl methacrylate. 4. Claim 2, characterized in that the monomer (B) is diethylene glycol bisallyl carbonate
Plastic lens materials as described in Section 1.