JPH04117415A - Optical resin - Google Patents

Abstract

PURPOSE:To obtain an optical resin improved in mechanical properties, inoclorousness, handleability in curing, refractive index, chromatic aberration, transparency, etc., by polymerizing a specified organosulfur compound with a polymerizable monomer. CONSTITUTION:One mol of divinylbenzene is allowed to react with about 1 mol of a thiophenol at 0-100 deg.C for 3-48hr to obtain an organosulfur compound (A) of the formula (wherein X is halogen or methyl; (l) is 1-2; and (m) and (n) are 0-1). 30-95wt.% component A is polymerized with a polymerizable monomer (B) at 0-200 deg.C for 1-48hr in an inert gas atomosphere in the presence of a radical polymerization initiator comprising 10 pts.wt. or below, per 100 pts.wt. total of components A and B, organic peroxide or azo compound having a 10-hr half-life temperature of 160 deg.C or below to obtain the title resin.

Description

DETAILED DESCRIPTION OF THE INVENTION <Field of Industrial Application> The present invention relates to an optical resin, and more particularly to an optical resin that is excellent in optical properties such as refractive index, chromatic aberration, and transparency, and various mechanical properties.

<Prior Art> In recent years, synthetic resin materials that are lightweight, easy to mold, have excellent impact resistance, dyeability, etc. have been used as lens materials instead of inorganic glass. As the synthetic resin material, for example, polymethyl methacrylate, polydiethylene glycol bisallyl carbonate, polystyrene, and polycarbonate are known. Although the polymethyl methacrylate and polydiethylene glycol bisallyl carbonate have excellent lightness and impact resistance, their refractive index is as low as about 1.49, so when used as a lens, a thicker lens is required compared to inorganic glass. The drawback is that it is not suitable for high magnification and weight reduction.

Furthermore, although polystyrene and polycarbonate have a high refractive index of about 1.58 to 1.59, since they are thermoplastic resins, they have the problem of easily causing optical distortion due to birefringence during injection molding. It has drawbacks such as lack of solvent resistance and scratch resistance.

Recently, several technical proposals have been made to improve these conventional drawbacks with high refractive index. For example, JP-A-1-309002 discloses a plastic lens made by curing a distyryl-type organic sulfur compound and a trivalent or tetravalent thiol compound; Furthermore, a sulfur-containing plastic lens is produced by mixing and curing a compound having 1.3 or more vinyl groups on a molar average and a compound having 1.1 or more thiol groups on a molar average in a specific ratio. JP-A No. 2-58001 proposes a high refractive index optical resin obtained by reacting a dimercaptobenzene nuclear substitute with a compound having at least two reactive unsaturated groups per molecule. .

<Problems to be Solved by the Invention> However, although the above-mentioned optical resins have a high refractive index, they have problems in terms of chromatic aberration, and furthermore, the thiol compounds used as raw materials have a strong odor, making them difficult to work in. There is also a problem in that handling properties are poor due to the high viscosity of the raw resin.

Furthermore, optical resins obtained by polyaddition and polycondensation have drawbacks such as poor yields because it is difficult to control the polymerization reaction.

Therefore, an object of the present invention is to provide a resin for plastic lenses or other optical applications that has desirable refractive index, chromatic aberration, transparency, etc., excellent mechanical properties, low odor, and excellent handling properties during curing. The object of the present invention is to provide a resin for optical use.

Means to solve problems〉 According to the present invention, the following general formula (I) (In the formula, X represents a halogen atom or a methyl group.

Further, there is provided an optical resin obtained by polymerizing an organic sulfur compound represented by (Ω represents 1 or 2, m and n represent O or 1) and a polymerizable monomer as raw material monomers.

The present invention will be explained in more detail below.

The organic sulfur compound used as an essential raw material monomer component in the present invention can be represented by the following general formula (1), where X represents a halogen atom or a methyl group. Also, Q
represents 1 or 2, and m and n represent O or 1. Examples of the organic sulfur compound represented by the general formula (1) include the following, which can be used alone or as a mixture.

The organic sulfur compound can be prepared, for example, by a method in which 1 mol of divinylbenzene and 1 mol of thiophenol are reacted, preferably at a reaction temperature of 0 to 100°C, for 3 to 48 hours. In this case, divinylbenzene can be used in a para form, a meta form, or a mixture thereof.

In the present invention, examples of the polymerizable monomer used as a raw material monomer component include styrene, P-methylstyrene, p-chlorostyrene, 0-chlorostyrene, p-
Bromstyrene, 0-bromstyrene, vinyl acetate, vinyl propionate, methyl methacrylate, butyl methacrylate, methyl acrylate, ethyl acrylate, phenyl acrylate, phenyl acrylate, benzyl acrylate, benzyl methacrylate, bromphenyl methacrylate, acrylonitrile, methacrylaterile, 2, 2-bis(4-methacryloyloxyethoxyphenyl)propane, 2.2-bis(4-acryloyloxyethoxyphenyl)propane, diethylene glycol bisallyl carbonate, diallyl tetrachlorophthalate, diallyl phthalate, divinylbenzene, divinylbiphenyl, ethylene glycol Bismethacrylate, diethylene glycol bismethacrylate,
Ethylene glycol bisacrylate, diethylene bisacrylate, dipropylene glycol bismethacrylate, triethylene glycol bisacrylate, tetraethylene glycol bisacrylate, bisphenol A bismethacrylate, diallyl tetrachlorophthalate, diallyl isophthalate, allyl methacrylate,
Vinylethylbenzene, divinylethylbenzene, 2-
Preferred examples include hydroxy-1,3-dimethacryloxypropane, propylene glycol bisacrylate, hexaethylene glycol bisacrylate, octaethylene glycol bisacrylate, and decaneethylene glycol bisacrylate.

In the present invention, the blending ratio of the organic sulfur compound, which is a raw material component, and the polymerizable monomer is not particularly limited, but preferably the organic sulfur compound is added to the total raw material monomer component from 30 to It may be blended in an amount of 95% by weight, particularly preferably in the range of 60 to 90% by weight. When the blending ratio exceeds 95% by weight,
If it is less than 30% by weight, sufficient mechanical strength cannot be obtained, and a sufficient refractive index cannot be obtained, which is not preferable.

To prepare the high refractive index optical resin of the present invention, for example,
It can be obtained by heating or copolymerizing each of the raw material monomer components 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 lower can be used, and specifically, for example, benzoyl peroxide,
Diisopropyl peroxydicarbonate, tert-butyl peroxy-2-ethylhexanoate, tert-butyl peroxy pivalate, tert-butyl peroxy diisobutyrate, lauroyl peroxide, t-butyl peroxy acetate, tert-peroxy octoate, tertiary peroxyoctoate butyl peroxybenzoate,
Examples include azobisisobutyronitrile, which can be used alone or as a mixture. The amount of the radical polymerization initiator used is 100% of the total raw material monomer components.
It is not more than 10 parts by weight, particularly preferably not more than 5 parts by weight.

In order to carry out the heating polymerization or copolymerization, for example, each of the raw material monomer components and a radical polymerization initiator are directly charged into a desired mold, and polymerized by heating preferably at 0 to 200 ° C. for 1 to 48 hours. be able to. At this time, the polymerization system is preferably carried out under an inert gas atmosphere such as nitrogen, carbon dioxide, or helium. In addition, before the polymerization, the raw material monomer components are heated at, for example, 0 to 200°C.
After prepolymerizing for 0.5 to 48 hours, it can be charged into a desired mold and post-polymerized.

Moreover, additives such as a UV absorber and a coloring inhibitor can be added to these raw material monomers as necessary.

Furthermore, various surface treatments can be performed after curing in order to improve the surface properties of the cured product.

<Effects of the Invention> The optical resin of the present invention has a refractive index of 1.55 or more and a high Abbe number, and has small chromatic aberration and optical distortion.
It also has excellent optical transparency, heat resistance, solvent resistance, and impact resistance, and furthermore, has a low specific gravity and can be lightweight. In addition, there is no bad odor characteristic of sulfur compounds when charging and curing the monomer composition, and the monomer composition has a low viscosity, so it has excellent handling properties and is easy to control the reaction during curing polymerization and molding. Therefore, 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.

Example 1 9 g of the organic sulfur compound shown in Table 1 (meta form: para form = 2
: 3. A monomer composition was obtained by adding and mixing 0.05 g of tert-butyl peroxybenzoate to a raw material monomer consisting of 1 g of divinylbenzene (weight ratio) and 1 g of divinylbenzene.

Next, the seven-layer composition was placed in two glass molds, placed in a constant temperature bath at 80°C, heated at a curing temperature of 80°C for 6 hours, and further heated to 100°C for 3 hours. Finally, it was heated at 100°C for 3 hours. 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 the refractive index, Atsube number, b*
The value and heat resistance were measured according to the following method. The results are shown in Table 1.

-Refractive index and Atsube number: Measurements were performed using an Atsube refractometer (manufactured by Atago Co., Ltd.) and a saturated methyl iodide solution as an intermediate solution.

-b* value (yellowness): Measured using Photometer Model 1001 manufactured by Nippon Denshoku Industries Co., Ltd. Note that the smaller this value is, the lower the degree of yellowness is, and the better.

・Heat resistance: Those with no deformation or discoloration in an oil bath at 130°C are rated ○, and those with deformation or discoloration are rated X.

11-7- A cured resin was prepared in the same manner as in Example 1, except that the raw material monomers shown in Table 1 were used, and each measurement was performed. The results are shown in Table 1. In addition, in each organic sulfur compound in the table, the position of the vinyl group is a mixture of meta body: para body = 2:3 (weight ratio), and in Example 7, the position of the methyl group is furthermore.

For each, ortho form: meta form: para form = 1:2:3 (
It was a mixture of (weight ratio).

Comparative Examples 1 to 3 Cured resins were prepared in the same manner as in Example 1, except that the monomers shown in Table 2 were used, and each measurement was performed. The results are shown in Table 2.

(Margin below)

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, methyl, or a group. Also, l is 1 or 2 An optical resin obtained by polymerizing an organic sulfur compound represented by (wherein m and n represent 0 or 1) and a polymerizable monomer as raw monomer components.