JPS597901A - Plastic lens high in refractive index - Google Patents

Abstract

PURPOSE:To reduce color aberration, by using a copolymer of a specified monomer and a radically polymerizable monomer. CONSTITUTION:The copolymer to be used is made from the first monomer represented by the shown general formula in which X is H or CH3 and (n) is 0, 1, or 2 and the second radically polymerizable monomer being to have >=1.55 refractive index when it is homopolymerized. As said second monomer, a monomer having a sulfur atom, such as vinylthiophene or vinyl phenyl sulfide, is used. A preferable amt. of the second monomer to be used is 10-70wt%.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a high refractive index synthetic resin lens with little chromatic aberration. Conventionally, inorganic glass has been used for double mirror lenses, but in recent years synthetic resins, such as diethylene glycol bisallyl carbonate (hereinafter referred to as 0R
39) has come to be used.

Synthetic resin lenses are superior in lightness, dyeability, impact resistance (safety), etc., compared to inorganic glass lenses.

However, the refractive index of OH39 polymer is 1.50,
Refractive index of general inorganic glass (crown glass) 1.52
It is lower than 3. Therefore, it has the disadvantage that the lens thickness and edge thickness become large.

Recently, JP-A-54-77686, JP-A-56-1662
14. Synthetic resin lenses with a high refractive index have been proposed as seen in Japanese Patent Application Laid-Open No. 57-54901.

Since these synthetic resin lenses have a high refractive index, they have the characteristic that the lens wall thickness and edge thickness can be made thinner than conventional OH39 polymer products. However, although the refractive index was increased, the Abbe number was significantly lower at 60. As a result, the chromatic aberration of the lens increases, which has the drawback that the range of power that can be used as a mirror lens is extremely limited in practice.

In general, the Atsbe number ν is given by the following formula, [Ijle lenses must have at least 35, and materials having 40 or more are particularly preferable. Another object of the present invention is to provide a synthetic resin lens that satisfies the excellent transparency, workability, light resistance, etc. required of mirror lenses.

One or more first monomers represented by (X:H or OH3J": Or i or 2) and one or more radically polymerizable monomers whose refractive index is 1.55 or more. The second monomer includes styrene, α-methylstyrene<p-methylstyrene, p-methoxystereoallyl cinnamate,
Phenyl acrylate, phenyl methacrylate, benzyl acrylate, pencil methacrylate, α-su7
Thyl acrylate, α-naphthyl methacrylate, 1-
vinylnaphthalene, 2-vinylnaphthalene, N-vinylcarbazole, bisphenol A dimethane relay), 2
．． Monomers having an aromatic ring such as 2-bis(4-methacryloyloxyethoxyphenyl)propane, diallyl phthalate, diallyl isocyanurate, triallyl cyanurate, triallyl isocyanurate, chlorstyrene,
Dichlorostyrene, 0-chlorphenylmethppvv-to, p-chlorphenyl methacrylate, 0-chlorphenylacrylate, p-chlorphenylac! JL/
-t, 21416-) lychlorophenylacrylate,
2.4.6-) dichlorophenyl methacrylate, 2.
4.6-tri-10mphenylacryl), 2.4+6
-1) f-bromphenyl methacrylate-'r-1p-bromphenyloxyethyl methacrylate, 2,4.6-)
Lipromophenyloxyethyl methacrylate, Tetrachlorobisphenol A dimethacrylate, Tetrabromobisphenol A dimethacrylate, 2,2-bis(
A monomer containing a barodene atom such as 4-methacryloyloxyethoxy3,6-dibromphenyl)propane,
A monomer having a sulfur atom such as vinyl thiophene/vinylphenyl sulfide can be used.

The preferred amount of the first monomer used is in the range of 60 to 90% by weight; The preferred use f of the Qlii form is in the range of 10 to 70% by weight.

The synthetic resin lens according to the present invention can be obtained by injecting a liquid mixture of the polymerization body and a polymerization initiator into a mold made of a combination of a glass mold and a resin gasket, and then heating the mixture. In addition, it is possible to cast by ultraviolet polymerization, radiation polymerization, and Norazuma tomoshi, in addition to the darning method. It is also possible to obtain lenses by compression molding, transfer molding, injection molding, etc. of the particles.In addition, when manufacturing the entire lens according to the present invention,
It goes without saying that ultraviolet absorbers, antioxidants, antistatic agents, dyes, etc. may be added as necessary.

The polymerization conditions for the lens according to the present invention cannot be determined unambiguously because they vary depending on the type of monomer and the polymerization initiator, but in general, a range of 60° to 90°C is used for one rationality. The polymerization time used is in the range of 6 to 72 hours. Examples of polymerization initiators that can be used include commonly used initiators such as azobisin butyronitrile, penzoyl peroxide, and diisopropyl peroxydicarbonate.

The resin lens of the present invention thus obtained has both a high refractive index and a large Abbe's number, and has lens performance that could not be satisfied by conventional high refractive index lenses. Furthermore, one of the features of the present invention is that it satisfies the practicality as an If lens in terms of transparency, light resistance, workability, etc.

Next, in order to better explain the present invention, Examples will be described. Example 1 70 parts of dicyclopentenyl acrylate, 30 parts of α-naphthyl methacrylate, 0.2 m of benzoyl peroxide,
2-Hydroxy-4-n-octoxybenzophenone 0
．． A mixture of 1 part was poured into a mold consisting of two if-) molds and a vinyl chloride gasket, and then kept at 60°C for 10 hours and at 80°C for 6 hours. After completing the chassis, the lens was removed from the mold and annealed at 100° C. for 1 hour. The obtained lens had excellent optical properties such as a transmittance of 90%, a refractive index of 1.573, and an Atsbe's number of 40. It also had excellent workability using a beading machine and light resistance using a Uniday meter. Furthermore, it was easy to apply an antireflection film by vacuum deposition, and the transmittance of the lens was improved to 97%, making it possible to obtain an extremely easy-to-see eyeglass lens.

Examples 2 to 18 Table 1 shows the optical properties of lenses cast and stacked in the same manner as in Example 1. All of these lenses could be coated with an antireflection film.

Comparative Example 1 Mixture g' consisting of 60 m of styrene, 60 parts of 2,2-bis(4-methacryloyloxy-3,5-dibromphenyl)propane, 10 parts of allyl cinnamate, and 0.2 part of diisozolyl peroxycarbonate. After pouring into a mold consisting of two glass molds and an ethylene-vinyl acetate gasket, the temperature was raised from 40°C to 80°C over 24 hours.

After 1 cup, remove the lens from the mold and heat it at 120°C.
Time annealed. The obtained lens has a transmittance of 90
%, refractive index of 1.592, and Atsbe's number of 60, and when used as an ophthalmic lens, significant chromatic aberration occurred, making it extremely difficult to see.

Claims (4)

[Claims] (1) One or more first monomers represented by the general formula (X is H or OH3, and n is a number of 0, 1" or 2) and a homopolymer. A high refractive index synthetic resin lens made of a copolymer with one or more radically polymerizable second monomers having a refractive index of 1.55 or more. (2) High refractive index synthetic resin lens 0 according to claim 1, wherein the second monomer is a monomer having an aromatic ring. (3) The high refractive index synthetic resin lens according to claim 1, wherein the second monomer is a monomer having a halogen atom. (4) The daytime refractive index plastic lens according to claim 1, wherein the second monomer is a monomer containing M sulfur atoms.