JPS6134007A - Optical resin and its production - Google Patents

Abstract

PURPOSE:To obtain an optical resin excellent in heat resistance, high refractive index, low shrinkage, weather resistance, mold release, etc., by (co)polymerizing a monomer mixture based on a specified dicarboxylate diester. CONSTITUTION:A monomer mixture comprising 95-10pts.wt. dicarboxylate diester of the formula (wherein at least one of R<1> and R<2> is an aromatic ring-containing ester residue) and 5-90pts.wt. monomer having a radical-polymerizable double bond (e.g., diglycidyl fumarate) is mixed with 10wt% or below organic peroxide or azo compound, as a polymerization initiator, having a selected 10hr half-life temperature <=100 deg.C (e.g., benzoyl peroxide), poured into a predetermined mold and cured by heating at 30-100 deg.C for about 10-60hr to obtain an optical resin excellent in refractive index and useful for plastic lenses, prisms, optical fibers, etc.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an optical resin made of a polymer or a copolymer of a diester of a special dicarboxylic acid. This invention relates to optical resins with excellent mold releasability.

Conventionally, plastic materials have been used as a substitute for inorganic glass, taking advantage of their excellent properties such as transparency, lightness, safety, and workability.

Typical examples include polymethyl methacrylate,
Examples include polycyclohexyl methacrylate, polydiethylene glycol bisallyl carbonate, and polystyrene.

Although these plastic materials are inferior to inorganic glass in scratch resistance, refractive index, heat resistance, etc., they are widely used in the optical field by taking advantage of the above-mentioned excellent properties. However, for example polymethyl methacrylate, poly 7 chlorohexyl methacrylate and polydiethylene glycol bisallyl carbonate, the refractive index ilD:
1.49 to 150, which is low, so when molded into lenses, it is required to be much thicker than inorganic glass, and in cast molding, the shrinkage rate during heat curing is extremely high, at 10 to 20 inches. Therefore, it required a fairly high level of skill to mold, and it also had the disadvantage of poor heat resistance.

In addition, the refractive index of polystyrene and polycarbonate is n. Although it has a high value of -1.59, it has shortcomings in weather resistance, chemical resistance, and heat resistance, and the molding method is mostly melt molding such as injection molding, and cast molding is advantageous for producing a wide variety of products. It had drawbacks such as not being legal.

As a result of intensive studies aimed at improving these conventional drawbacks, the present inventors have found that resins made of diester polymers of dicarboxylic acids or copolymers have high heat resistance, high refractive index,
The present invention was completed by discovering that it has excellent low shrinkage properties and mold release properties.

The present invention provides an optical resin obtained by polymerizing or copolymerizing a diester of a dicarboxylic acid represented by the general formula H 2 in which at least one of R1 and R2 is an ester residue having an aromatic ring, and a method for producing the same. It is something to do.

The diesters of dicarboxylic acids used in the present invention include diphenyl fumarate, dibenzyl fumarate, diphenyl fumarate, di(chlorphenyl) fumarate, cy(brophenyl) fumarate, di(chlorobenzyl) fumarate, di(brombenzyl) ) fumarate, imbroby-phenyl fumarate, inpropyl-benzyl fumarate, cyclohexyl-phenyl fumarate, cyclohexyl-benzyl fumarate, allyl-phenyl fumarate, allyl-benzyl fumarate, diphenyl maleate, dibenzyl Examples include malate, allyl phenyl maleate, allyl benzyl maleate, and the like.

Both of the above-mentioned 7-malates and maleates are characterized in that at least one of the ester residues has an aromatic ring. more preferable than

The optical resin of the present invention can be obtained by polymerizing one or more diesters of dicarboxylic acids. Moreover, it is also possible to obtain it by radical copolymerization of the diester of the above dicarboxylic acid and one or more monomers having a radically polymerizable double bond.

Examples of monomers having radically polymerizable double bonds include aromatic vinyl compounds such as styrene, O-methylstyrene, 〇-chlorostyrene, and divinylbenzene, methacrylic acid esters such as methyl methacrylate-1- and butyl methacrylate, and methyl. Examples include acrylic acid esters such as acrylate and ethyl acrylate, vinyl carboxylates such as vinyl acetate and vinyl propionate, and allyl compounds such as diallyl fumarate, diallyl maleate, diallyl phthalate, and diethylene glycol bisallyl carbonate. In this case, the radically polymerizable double bond to the diester of the dicarboxylic acid is
1*: It is possible to carry out the composition ratio as small as 1, but preferably the diester of dicarboxylic acid/vinyl monomer (weight ratio) is in the range of 9515 to 10/90.

As the polymerization initiator used in polymerizing the polymer or copolymer according to the present invention, one or more organic peroxides or azo compounds having a 10-hour half-life temperature of tO0°C or less are selected. used. Examples include benzoyl peroxide, diinopropyl peroxydicarbonate, tert-butyl peroxy bivalate, tert-butyl peroxy neodecanoate, tert-butyl peroxy diisobutyrate, azobisisobutyl nitrile, and the like. The amount of the polymerization initiator used is preferably 100% by weight or less, more preferably 5% by weight or less based on the total weight of the raw material monomers. In order to obtain the optical resin by the polymerization or copolymerization in the present invention, it is preferable to directly charge a mixture of the monomer raw materials and a polymerization initiator into a desired mold and heat-cure the system. Alternatively, melt molding after copolymerization is not suitable. In this case, the polymerization system may be heated with an inert gas such as nitrogen,
It is also possible to use a method in which the material is substituted with carbon dioxide, helium, etc., or is slightly polymerized or copolymerized in an atmosphere, then charged into a desired mold, and heated and cured to complete the polymerization.

In addition, as for the temperature in the case of heating and curing, it varies depending on the polymerization initiator used, but it is 30 to 1 and 10 to 60.
It takes about an hour.

The optical resin of the present invention thus obtained has excellent heat resistance and weather resistance, and has a greatly improved refractive index, as well as low shrinkage during processing, compared to conventional optical resins. It also has excellent mold releasability, so it can be applied to plastic lenses, prisms, optical fibers, etc.

EXAMPLES The present invention will be explained in detail below using several examples, but the present invention is not limited by the examples.

Example 1 Allyl-benzyl 7 malate 100 kept at 40°C
Add 3 parts by weight of diimpropyl peroxydicarbonate as a polymerization initiator, pour this mixed solution into a mold made of two 200RX2Qcm hard glass plates and silicone rubber packing, and heat at 40''C under a nitrogen atmosphere.
It was held for 24 hours during the open period. Thereafter, it was held at 100'C for 24 hours to complete curing. Table 1 shows the properties of the obtained resin.

The shrinkage rate after curing was calculated according to the following formula from the change in linear shrinkage before and after polymerization from the scale marked on the glass plate.

The length refractive index before polymerization was measured using an Atsube refractometer, and the heat resistance was 150°.
Those in which the resin did not deform under the hot air of C were judged to have passed. Regarding mold releasability, a product that could easily release the polymer from the glass surface after curing was considered acceptable.

Example 2 Example except that 3 parts by weight of benzoyl peroxide was used as a polymerization initiator to 90 parts by weight of diphenyl fumarate and 10 parts by weight of diallyl fumarate kept at 60°C, and the polymerization was cured at 80°C for 24 hours. It was carried out in exactly the same manner as 1.

Example 3 The same procedure as in Example 2 was carried out except that 3 parts by weight of benzoyl peroxide was used as a polymerization initiator in addition to 903i parts of dibenzyl fumarate and 10 parts by weight of diallyl isophthalate, which were kept at 70°C.

Example 4 Except for using 3 parts by weight of diimpropyl peroxydicarbonate as a polymerization initiator in 50 parts by weight of allyl-benzyl fumarate, 40 parts by weight of 0-chlormethylenef, and 10 parts by weight of methyl methacrylate kept at 40°C. The same procedure as in Example 1 was carried out.

100 parts by weight of each monomer of glycol bisallyl carbonate 3 parts by weight of diisoprobyl peroxydidicarbonate were added as a polymerization initiator, and polymerization was carried out in exactly the same manner as in Example 1 to prepare a comparative example.

The above results are shown in Table 1.

It has a high refractive index of 155 or more, a shrinkage rate of /J·cm, and good heat resistance and mold release properties, so it can be seen that it is significantly superior to the comparative example as an optical resin.

Claims (1)

[Claims] 1. A dicarboxylic acid whose general formula is ▲A mathematical formula, a chemical formula, a table, etc.▼...(1) At least one of R_1 and R_2 is an ester residue having an aromatic ring. Optical resin made by polymerizing or copolymerizing diester. 2. The diester of dicarboxylic acid is diphenyl fumarate, dibenzyl fumarate, diphenethyl fumarate,
Claim No. 1, which is di(chlorphenyl) fumarate, di(bromphenyl) fumarate, isopropyl-phenyl fumarate, isopropyl-benzyl fumarate, cyclohexyl-phenyl fumarate, allyl-phenyl fumarate or allyl-benzyl fumarate. 1
Optical resin described in section. 3. The optical resin according to claim 1 or 2, wherein the copolymerization component is a monomer having a radically polymerizable double bond. 4. The general formula is ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼... (1) The main component is diester of dicarboxylic acid in which at least one of R_1 and R_2 is an ester residue having an aromatic ring. An optical resin characterized in that an organic peroxide or azo compound with a 10-hour half-life temperature of 100°C or less is blended with the raw material monomer as a polymerization initiator, and the mixture is injected into a predetermined mold and cured by heating. Manufacturing method.