JPS6343909A - Optical resin and its production - Google Patents

Abstract

PURPOSE:To obtain the title resin having excellent transparency and heat resistance, small shrinkage during molding by polymerization and a high refractive index, by (co)polymerizing a specified mesaconate with, optionally, a comonomer. CONSTITUTION:100pts.wt. mesaconate of formula I [wherein A1-2 are each a group of formula II or III (wherein X is a halogen and m is 0-5), a 1-12C alkyl or alkenyl or a 3-12C cycloalkyl] is (co)polymerized with, optionally, 10,000-1pt.wt. radical-polymerizable vinyl monomer, crosslinking vinyl monomer or crosslinking allyl monomer at 30-70 deg.C to some extent in the presence of 10pts.wt. or below (based on 100pts.w.t. monomer feed) polymerization initiator comprising an organic peroxide of a selected 100hr half-life temperature <=120 deg.C and at least one azo compound; placed in a predetermined mold and cured by heating at 30-150 deg.C for 10-48hr to obtain the title colorless, transparent resin having a refractive index nD as high as 1.55 or above and an Abbe's number >=30.

Description

[Detailed Description of the Invention] <Industrial Application Field> The present invention relates to an optical resin obtained by polymerizing or copolymerizing a specific mesaconate ester and a method for producing the same. This invention relates to an optical resin with excellent properties and a method for producing the same.

<Conventional technology and problems> Conventionally, plastic materials have been characterized by their transparency, lightness,
Taking advantage of its excellent properties such as safety and processability.

It has been used as a substitute for inorganic glass. Typical examples include polymethyl methacrylate, polydiethylene glycol bisallyl carbonate, polystyrene, polycarbonate, and the like.

Although these plastic materials are inferior to inorganic glass in scratch resistance, curvature, and heat resistance, they are widely used in the optical field by taking advantage of the above-mentioned excellent properties. However, for example, polymethyl methacrylate and polydiethylene glycol bisallyl carbonate have a low refractive index of approximately 1.49 to 1.50, so when used in fields that utilize refractive index such as lenses, inorganic glass is preferred. In comparison, it requires a thick material, which has the drawback of not being suitable for the miniaturization and weight reduction of recent optical materials.

In addition, although polystyrene and polycarbonate have a high refractive index of n (1 = about 1.59 to 1.60),
It has shortcomings in solvent resistance and birefringence.

In addition, many of the molding methods involve melt molding such as injection molding, which has drawbacks such as being unsuitable for cast molding, which is useful for producing a wide variety of products.

<Object of the Invention> The present invention provides an optical resin that has desirable colorless transparency and a high refractive index as an optical resin, has a low shrinkage rate during polymerization molding, has excellent heat resistance, and is suitable for cast molding. The purpose is to provide a manufacturing method.

<Means for Solving the Problems> According to the present invention, the following general formula (wherein A1. ,
or represents a halogen atom, 1m represents 0 or an integer of 1 or more and 5 or less, and R represents an alkyl group having 1 to 12 carbon atoms, an alkenyl group, or a cycloalkyl group having 3 to 12 carbon atoms) An optical resin obtained by polymerizing a mesaconate ester or copolymerizing the mesaconate ester and a comonomer is provided.

Further, according to the present invention, the following general formula (where A, , A are the same or different groups and at least one selected group represents a group having an aromatic ring,
or represents a halogen atom, m represents O or an integer of 1 or more and 5 or less, and R represents an alkyl group having 1 to 12 carbon atoms, an alkenyl group, or a cycloalkyl group having 3 to 12 carbon atoms) In the presence of one or more polymerization initiators selected from organic peroxides and azo compounds having a 10-hour half-life temperature of 120°C or less, ,
A method for producing an optical resin is provided, which is characterized in that the resin is placed in a predetermined mold and cured by heating.

The present invention will be explained in detail below.

In the present invention, the following general formula % formula % (1) (wherein A□ and Am are the same or different groups and at least one selected group represents a group having an aromatic ring,
or represents a halogen atom, 1m represents 0 or an integer of 1 or more and 5 or less, and R represents an alkyl group having 1 to 12 carbon atoms, an alkenyl group, or a cycloalkyl group having 3 to 12 carbon atoms) Mesaconic acid ester is used. The phenyl group and benzyl group in the mesaconate ester may be substituted with a halogen atom (m = an integer of 1 or more and 5 or less) or may not be substituted with a halogen atom (m -0). When the mesaconate group is an alkyl group, an alkenyl group, or a cycloalkyl group, if the number of carbon atoms is 13 or more, physical properties such as polymerizability and heat resistance deteriorate, so that it cannot be used.

Specific examples of mesaconate esters that can be used in the present invention include diphenyl mesaconate, di(orthochlorophenyl) mesaconate, di(orthobromphenyl) mesaconate, and di(orthobromphenyl) mesaconate.
parachlorophenyl) ester, mesaconic acid di(metabromphenyl) ester, mesaconic acid di(2', 4')
-dichlorophenyl) ester, mesaconate varabromphenyl-orthobromphenyl diester, mesaconate benzyl-phenyl diester, mesaconate dibenzyl ester, mesaconate di(orthochlorobenzyl ester), mesaconate di(orthobromphenyl) ) ester, mesaconic acid di(metabromobenzyl) ester,
Orthochlorobenzyl mesaconate diester, benzyl mesaconate orthobromobenzyl diester, di(2',4'-dichlorobenzyl) mesaconate, methyl mesaconate phenyl diester, isopropyl mesaconate phenyl diester, mesaconic acid Examples include cyclohexyl-phenyl diester, ethyl-benzyl mesaconate diester, isopropyl-benzyl mesaconate diester, cyclohexyl-benzyl mesaconate diester, allyl-benzyl mesaconate diester, methallyl-benzyl mesaconate diester, and the like. However, when the mesaconic acid diesters represented by the general formula (1) in the above specific examples have different A groups and A2 groups, the names are given in the order of A group and A2 group.

The optical resin of the present invention can be obtained by polymerizing one or more of the above mesaconate esters. or,
The above mesaconic acid ester and a comonomer may be copolymerized. As the comonomer, one or more radically polymerizable vinyl monomers or crosslinkable vinyl monomers can be used.

Examples of radically polymerizable vinyl monomers or crosslinkable vinyl monomers include styrene, p-methylstyrene, p-
Chlorstyrene, 0-chlorostyrene, p-bromstyrene, 0-bromstyrene, p-divinylbenzene, m
- Divinylbenzene, divinylbiphenyl, vinyl acetate, vinyl propionate, methyl methacrylate, butyl methacrylate, methyl acrylate, ethyl acrylate, phenyl methacrylate, phenyl acrylate, benzyl methacrylate, benzyl acrylate, bromphenyl methacrylate, acrylonitrile, methacrylatrile, ethylene glycol di Methacrylate, diethylene glycol dimethacrylate, ethylene glycol diacrylate, diethylene glycol acrylate, dipropylene glycol dimethacrylate, bisphenol A dimethacrylate, 2.2-bis(4-
methacryloyloxyethoxyphenyl)propane, 2
, 2-bis(4-acryloyloxyethoxyphenyl)propane, diallyl phthalate, diallyl tetrachlorophthalate, diallyl isophthalate, diethylene glycol bisallyl carbonate, diallyl tetrachlorophthalate, etc., but the solvent resistance of the resulting resin ,
For the purpose of increasing heat resistance, it is preferable to select at least one type of crosslinkable polyfunctional vinyl monomer. Examples of such vinyl monomers include divinylbenzene, ethylene glycol di(meth)acrylate, diallyl phthalate, and the like.

The copolymerization ratio of comonomer to mesaconate ester is 10 parts by weight per 100 parts by weight of mesaconate ester.
The range is preferably from 0.00 to 1 part by weight.

Furthermore, a range of 500 to 10 parts by weight is preferable.

In this case, if it exceeds 1000 parts by weight, the refractive index of the resulting resin will be significantly lowered, and if it is less than 1 part by weight, the effect of copolymerization of the comonomer will not be sufficient.

As the polymerization initiator used in polymerizing the polymer or copolymer of the present invention, one or more selected organic peroxides and azo compounds having a 10-hour half-life temperature of 120°C or less are used. Ru.

Examples of such initiators include benzoyl peroxide, diisopropyl peroxycarbonate, tert-butyl peroxy 2-ethylhexanoate, tert-butyl peroxy pivalate, tert-butyl peroxy diisobutyrate, lauroyl peroxide, azobis Examples include isobutyronitrile. The amount of the polymerization initiator used is preferably 10 parts by weight or less, more preferably 5 parts by weight or less, based on 100 parts by weight of the raw material. In preparing the optical resin of the present invention, the raw materials are
A method is used in which a polymerization initiator is added to the mixture, the mixture is directly charged into a desired mold, and the system is heated and cured. Processing after polymerization or copolymerization is not suitable.

In this case, it is desirable to replace the polymerization system with an inert gas such as nitrogen, carbon dioxide, helium, etc. or bring it under an atmosphere at an appropriate time.Also, after adding a polymerization initiator to the raw material monomers, the polymerization system is heated at a predetermined temperature (30 to 30℃). It is also possible to carry out a slight polymerization or copolymerization in advance at 70° C.), then charge it into a predetermined mold, and heat and harden it to complete the polymerization.

The temperature for heating and curing is preferably in the range of 30 to 100°C, although it varies depending on the polymerization initiator used, and is more preferably about the 10-hour half-life temperature of the polymerization initiator used. Also.

It is also possible to raise the curing temperature at an appropriate time for the purpose of shortening the curing time and disposing of unreacted polymers and polymerization initiators. In this case, the total time required for curing is 10 to 48
It takes about an hour.

<Effects of the Invention> The optical resin of the present invention has a high refractive index with a no of 1.55 or more, is colorless and transparent with an Abbe number of 30 or more, has a small shrinkage rate during molding polymerization, and has good heat resistance. The present invention provides a material that improves the shortcomings of conventional optical resins, such as excellent properties, and can be applied to optical fields such as eyeglass lenses, camera lenses, optical elements, and high refractive index resin plates.

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

In addition, various physical properties were measured by the methods described below.

Refractive index, Atsube number - Atsube refractive index specific gravity - Obtained from resin weight/resin volume by the underwater substitution method.

Polymerization shrinkage rate was determined from the specific gravity (ρM) of the raw Motsumar composition and the specific gravity (ρP) of the cured resin according to the formula (1-ρP/ρM).

Heat Resistance - After being left in a dryer at -130''C for 2 hours, no change in the resin such as deformation 2 or coloring was observed as a pass, and a mark of ○ was given, while a fail was marked as a mark of x.

A raw material mixture consisting of 7g of mesaconic acid diphenyl ester and 3g of divinylstyrene in the backyard.
．． 2 g of the 7-mer composition mixed and heated to 60'C.
The resin was placed in a glass mold (using a silicone gasket) and cured in a constant temperature bath at 70°C for 24 hours under a nitrogen stream. After annealing at 100°C for 2 hours, the cured resin was removed from the mold and had the properties listed above. We conducted an evaluation using a test.

Examples 2 to 6, Comparative Examples 1 and 2 By the same method as in Example 1, cured resins were prepared using raw material monomers of various compositions and a predetermined radical initiator under curing conditions. The results are shown in Table 1.

As a comparative example, a similar experiment was conducted using diethylene glycol bisallyl carbonate and styrene, and the results are also described.

Claims (1)

[Claims] 1) General formula ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ (In the formula, A_1 and A_2 are the same or different groups, ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼, ▲ Numerical formulas, At least one group selected from ▼ or R represents a group having an aromatic ring, X represents a halogen atom, m represents 0 or an integer greater than or equal to 1 and less than or equal to 5, and R is an alkyl group having 1 to 12 carbon atoms, an alkenyl group, or a cycloalkyl group having 3 to 12 carbon atoms), or by copolymerizing the mesaconate ester and a comonomer. Optical resin. 2) the comonomer is a radically polymerizable vinyl monomer;
The optical resin according to claim 1, which is a crosslinkable vinyl monomer. 3) General formula ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ (In the formula, A_1 and A_2 are the same or different groups, ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼, ▲ There are mathematical formulas, chemical formulas, tables, etc. At least one group selected from ▼ or R represents a group having an aromatic ring, X represents a halogen atom, m represents 0 or an integer of 1 or more and 5 or less, and R represents a carbon number of 1 to 12 (representing an alkyl group, an alkenyl group, or a cycloalkyl group having 3 to 12 carbon atoms) or a mixture of the mesaconate ester and a comonomer 1
An optical device characterized by being placed in a predetermined mold and heat-cured in the presence of one or more polymerization initiators selected from organic peroxides and azo compounds having a 0-hour half-life temperature of 120° C. or less. Manufacturing method of resin for use. 4) The method for producing an optical resin according to claim 3, wherein the comonomer is a radically polymerizable vinyl monomer or a crosslinkable vinyl monomer.