JPH03296507A - Optical resin with high refractive index - Google Patents

Abstract

PURPOSE:To prepare the title resin which has excellent transparency, a high refractive index, a low density, and an excellent resistance to weathering, solvent, and impact and is useful as a spectacle lens, etc., by polymerizing a monomer contg. a specific org. sulfur compd. CONSTITUTION:A monomer contg. an org. sulfur compd. of formula I (wherein X is halogen; R1 and R2 are each alkylene; n is 0-3; and m is 1-3) [e.g. 1-5-bis(p- vinylbenzylthio)-3-oxapentane of formula II] is polymerized to give the title resin, which has a refractive index of 1.6 or higher, a low optical stress, a high optical transparency, a low density, and an excellent resistance to heat, solvent, and impact. The polymn. control and molding are easy. Hence, the resin is useful for a lens of a spectacle, camera, optical instrument, etc., and for other uses as an optical material.

Description

Detailed Description of the Invention <Industrial Application Field> The present invention relates to an optical resin, and more specifically, to a high refractive index optical resin that has excellent transparency and a high refractive index, and is useful for plastic lenses for glasses. Regarding resin for use.

<Prior art> In recent years, synthetic resin materials that are lightweight, easy to mold, have excellent impact resistance, and are dyeable have been used as optical materials such as plastic lenses in place of inorganic glass. For example, polymethyl methacrylate, polydiethylene glycol bisallyl carbonate, polystyrene, and polycarbonate are known. However, although polymethyl methacrylate and polydiethylene glycol bisallyl carbonate are themselves lightweight and have excellent impact resistance, they have a low refractive index of about 1.49, so when used as lenses, they are difficult to use compared to inorganic glass. The drawback is that it requires a thick lens, making it unsuitable for high magnification and weight reduction. In addition, the refractive index of polystyrene and polycarbonate is 1.58 to 1.58.
Although it is high at around 1.59, since these are thermoplastic resins, they have the problem of being prone to optical distortion due to birefringence during injection molding, and have other drawbacks such as poor solvent resistance and scratch resistance. be.

Recently, various technical proposals have been made to improve these conventional drawbacks. For example, JP-A-53-7
No. 787 discloses a copolymer of diethylene glycol biscarbonate and diallylisophthalate,
No. 9-81318 discloses a copolymer of diallyl phthalate and unsaturated fatty acid alcohol benzoate, and JP-A-59-191708 discloses a di(meth)acrylate containing bisphenol A, diallyl isophthalate and diethylene glycol. Copolymers with bisallyl carbonate and the like are disclosed.

However, all of the optical resins proposed above have a problem in that they have a low refractive index of 1.52 to 1.56 and that unreacted allyl monomers tend to remain.

Furthermore, in JP-A-57-28115, a copolymer of a styrene-based vinyl monomer and an unsaturated carboxylic acid heavy metal salt is disclosed, and in JP-A-60-55,007, a copolymer of halogen-substituted diallyl phthalate and Copolymers with Gen-substituted allyl benzoate have been proposed, but although these have a high refractive index of about 1.58 to 1.60, the specific gravity of the polymer is high and the drawback is that it is impossible to reduce the weight of lenses etc. There is.

Furthermore, in JP-A-55-1374.7.

Halogen-substituted styrene, bisphenol A-containing di(
In JP-A-59-133211, a copolymer of meth)acrylate, a benzyl methacrylate monomer, and a phenol methacrylate monomer is a copolymer of hydroxyl (meth)acrylate having an aromatic ring, a diisocyanate compound, and a styrene monomer. Copolymers have been proposed, but although these resins have a high refractive index of around 1.60, the polymerization reaction is well controlled, the specific gravity of the polymer is high, and the weather resistance is poor. It has the disadvantage of having problems.

<Problems to be Solved by the Invention> An object of the present invention is to provide a resin that has desirable optical transparency as a resin for plastic lenses or other optical applications, has excellent weather resistance, solvent resistance, and impact resistance, and further has The object of the present invention is to provide a high refractive index optical resin having a low specific gravity.

<Means for Solving the Problems> According to the present invention, the following formula (1) (wherein, X represents a halogen atom, R□ and R2 represent an alkylene group, and n is an integer of O to 3) and m is 1
A high refractive index optical resin obtained by polymerizing a raw material containing an organic sulfur compound represented by an integer of 3 to 3 is provided.

The present invention will be explained in more detail below.

The high refractive index optical resin of the present invention is characterized by containing a specific organic sulfur compound as an essential raw material monomer, preferably exhibits a high refractive index of 1.60 or more, and has excellent physical properties. It is a resin.

The organic sulfur compound used in the present invention has the following formula (
1).

(In the formula, X represents a halogen atom, R and R2 represent an alkylene group, n represents an integer of O~3, and m represents an integer of 1~3.
Indicates an integer of 3. Moreover, when m exceeds 3, manufacturing is difficult. Examples of the organic sulfur compound represented by formula (1) include 1°5-bis(P-vinylbenzylthio)-3-oxapentane, 1,5-bis(m-vinylbenzylthio)-3- Oxapentane, 1,8-bis(P-vinylbenzylthio)-3,6-thioxaoctane, 1,8-bis(m-vinylbenzylthio)-3,
6-thioxaoctane, 1,5-bis(〇-bromo p
-vinylbenzylthio)-3-oxapentane and the like, which can be used alone or as a mixture.

The organic sulfur compound can be easily prepared by, for example, coupling a corresponding dithiol compound and chloromethylstyrene in an appropriate solvent.

Further, the blending ratio of the organic sulfur compound in the raw material monomer is not particularly limited.

Preferably 1 to 100% by weight based on the entire raw material monomer
, particularly preferably in the range of 50 to 95% by weight. Furthermore, when the organic sulfur compound is blended in an amount of 1 to 30% by weight, it can also be used as a high-performance crosslinking agent having a high refractive index.

In the present invention, monomers other than the organic sulfur compound that can be used as raw material monomer components include, for example, styrene, p-methylstyrene, p-chlorostyrene, 0-chlorostyrene, p-bromstyrene 50-
Bromstyrene, vinyl acetate, vinyl propionate, methyl methacrylate, butyl methacrylate, methyl acrylate, ethyl acrylate, phenyl methacrylate, phenyl acrylate, benzyl acrylate,
Benzyl methacrylate, bromphenyl methacrylate, acrylonitrile, methacrylate trile, 2,2-
Bis(4-methacryloyloxyethoxyphenyl)propane, 2,2-bis(4-acryloyloxyethoxyphenyl)propane, diethylene glycol bisallyl carbonate, diallyl tetrachlorophthalate, diallyl phthalate, p-divinylbenzene, m-divinylbenzene, Divinylbiphenyl, ethylene glycol bis methacrylate, diethylene glycol bis methacrylate, ethylene glycol bis acrylate, diethylene bis acrylate, dipropylene glycol bis methacrylate, triethylene glycol bis acrylate, tetraethylene glycol bis acrylate, bisphenol A bis methacrylate, diallyl tetrachlorphthalate, Preferred examples include diallyl isophthalate, allyl methacrylate, propylene glycol bisacrylate, hexaethylene glycol bisacrylate, octaethylene glycol bisacrylate, and decaneethylene glycol bisacrylate.

In order to prepare the high refractive index optical resin of the present invention, it can be obtained, for example, by heating and polymerizing the above-mentioned raw material monomers in the presence of a radical polymerization initiator. As the radical polymerization initiator, an organic peroxide or an azo compound having a 10-hour half-life temperature of 160°C or less can be used, and specifically, for example, diisopropyl peroxydicarbonate, tert-butylperoxy-2- Ethylhexanoate, tert-butylperoxypivalate, tert-butylperoxydiisobutyrate, lauroyl peroxide, t-butylperoxyacetate, tert-peroxyoctoate, tert-butylperoxybenzoate, azobisisobutyronitrile, etc. They can be used alone or as a mixture. The amount of the radical polymerization initiator used is preferably 10 parts by weight or less, particularly preferably 5 parts by weight or less, based on 100 parts by weight of the raw material.

The heating polymerization can be carried out by, for example, directly charging the raw material monomer and the radical polymerization initiator into a desired mold, and heating preferably at 0 to 200° C. for 1 to 48 hours. At this time, the polymerization is preferably carried out under an atmosphere of an inert gas such as nitrogen, carbon dioxide, or helium.

In addition, before the polymerization, the raw material monomers may be mixed, for example, from 0 to
After prepolymerizing at 200° C. for 0.5 to 48 hours, it can also be charged into a desired mold and post-polymerized.

<Effects of the Invention> The high refractive index optical resin of the present invention has a high refractive index of 1.60 or more, has low optical distortion, and has excellent optical transparency, heat resistance, and It has excellent solvent resistance and impact resistance, and has a low specific gravity, allowing it to be made lighter. In addition, since reaction control during curing and polymerization and molding are easy, it is useful as a resin material for plastic lenses such as eyeglass lenses, camera lenses, and optical materials, or for other optical applications.

<Examples> Hereinafter, the present invention will be explained in more detail with reference to Examples and Comparative Examples, but the present invention is not limited thereto.

Mi 11 Town L 1.5-bis(p-vinylbenzylthio)-3-oxapentane (structural formula; 0.05g of tert-butyl peroxybenzoate was added to the raw material monomers consisting of 6g and 6g of styrene, and the monomer composition was The monomer composition was then placed in two glass molds, and heated to 80°C.
Place it in a constant temperature bath, heat it at 80℃ for 6 hours, and then heat it for 3 more hours.
The temperature was raised to 100° C. over an hour, and finally an annealing treatment was performed at 100° C. for 2 hours to obtain a cured resin. The obtained cured resin was taken out from the mold, and its refractive index, Abe's number, and transparency were measured according to the following methods. The results are shown in Table 1.

Refractive index and Atsube number: Atsube refractometer (Atago Co., Ltd. 1!5) Transparency: When observed with the naked eye, transparency is rated O, and b is slightly cloudy is rated Δ.

In place of the raw material monomers in Example 1, 40 parts by weight of 1.5-bis(p-vinylbenzylthio)-3-oxapentane and 1.5-bis(m-vinylbenzylthio) were added. )-3-oxapentane (structural formula; ; C exposed H+H2S-C2)!4 Akebonobe-Gan 2be◇→niH2)
A raw material monomer (Example 3) consisting of 40 parts by weight and 1,8-bis(m-vinylbenzylthio)-3°6-thioxaoctane (structural formula; 36 parts by weight of p-vinylbenzylthio)-3°6-dioxaoctane, 254 parts by weight of 1,8-bis(m-vinylbenzylthio)-3°6-dioxaoctane, and 1 methyl methacrylate.
0 parts by weight of the raw material monomer (Example 4), 1,
5-bis(0-bromo-pvinylbenzylthio)-3-
Oxapentane (structural formula; except that the raw material monomers shown in Table 2 were used, a cured resin was prepared in the same manner as in Example 1, and each measurement was performed.

This was used as a comparative example. The results are shown in Table 2.

A cured resin was prepared in the same manner as in Example 1, except that the raw materials (Example 5) consisting of 50 parts by weight and 50 parts by weight of styrene were used, and each measurement was performed. The results are shown in Table 1.

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Claims (1)

[Claims] The following general formula (I) ▲There are mathematical formulas, chemical formulas, tables, etc.▼...(I) (In the formula, X represents a halogen atom, R_1 and R_2 represent an alkylene group, and n is 0 Indicates an integer of ~3, m
is an integer of 1 to 3) A high refractive index optical resin obtained by polymerizing a raw material monomer containing an organic sulfur compound represented by the following.