JPH0644081B2 - Optical lens and manufacturing method thereof - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial field of application> The present invention relates to an optical lens obtained by polymerizing or copolymerizing a specific cinnamic acid ester and a method for producing the same, more specifically, a high refractive index, transparent TECHNICAL FIELD The present invention relates to an optical lens having excellent properties and a manufacturing method thereof.

<Prior Art and Problems> Conventionally, plastic materials have been used as substitutes for inorganic glass by taking advantage of their excellent properties such as transparency, lightness, safety and processability. Typical examples thereof include polymethyl methacrylate, polydiethylene glycol bisallyl carbonate, polystyrene and polycarbonate.

Although these plastic materials are inferior in scratch resistance, refractive index, and heat resistance to inorganic glass, they are widely used in the optical field by taking advantage of the above-mentioned excellent characteristics. However, for example, polymethyl methacrylate and polydiethylene glycol bisallyl carbonate have a low refractive index of about n _D = 1.49 to 1.50, and therefore, when used in the field of utilizing a refractive index such as a lens, as compared with inorganic glass. A thick material is required, and there is a drawback that it is not suitable for recent downsizing and weight saving of optical materials.

Further, polystyrene and polycarbonate have a high refractive index of n _D = 1.59 to 1.60, but have a high solvent resistance,
It has a defect in birefringence, and the molding method is often by melt molding such as injection molding, which is not suitable for a cast molding method useful for production of various items.

<Purpose of the Invention> The present invention provides an optical lens which has a desirable colorless transparency and a high refractive index as an optical lens, has a small shrinkage rate at the time of polymerization molding, is excellent in heat resistance, and is suitable for a casting method, and a method thereof. The purpose is to provide a manufacturing method.

<Means for Solving Problems> According to the present invention, the following general formula (In the formula, A is Or R, X represents a halogen atom, and l and m
Is an integer of 0 or 1 or more and 5 or less, and R is a carbon number of 3 to 1.
The present invention provides an optical lens obtained by polymerizing or copolymerizing a cinnamic acid ester represented by 2).

According to the invention, the following general formula (In the formula, A is Or R, X represents a halogen atom, and l and m
Is an integer of 0 or 1 or more and 5 or less, and R is a carbon number of 3 to 1.
A cinnamic acid ester represented by 2), or a mixture of a copolymerizable vinyl monomer copolymerizable with the cinnamic acid ester and the cinnamic acid ester.
An optical lens characterized by being placed in a predetermined mold and cured by heating in the presence of one or more polymerization initiators selected from organic peroxides and azo compounds having a time half-life temperature of 100 ° C. or less. A method of manufacturing the same is provided.

Hereinafter, the present invention will be described in detail.

In the present invention, the following general formula (In the formula, A is Or R, X represents a halogen atom, and l and m
Is an integer of 0 or 1 or more and 5 or less, and R is a carbon number of 3 to 1.
2 represents a cycloalkyl group of 2). The phenyl group and benzyl group in the cinnamic acid ester may be substituted with a halogen atom (l, m
Is an integer of 1 or more and 5 or less), and may not be substituted with a halogen atom (l and m are 0). When the ester group of the cinnamic acid ester is an alkyl group or a cycloalkyl group, it cannot be used when the number of carbon atoms is 13 or more because the physical properties such as polymerizability and heat resistance are deteriorated.

Specific examples of the cinnamic acid ester that can be used in the present invention include cinnamic acid phenyl ester, cinnamic acid (orthochlorophenyl) ester, cinnamic acid (parachlorophenyl) ester, cinnamic acid (orthobromphenyl) ester, Cinnamic acid (para-bromophenyl) ester, cinnamic acid (meta-bromophenyl) ester, cinnamic acid (2 ', 4'
-Dichlorophenyl) ester, orthochlorocinnamic acid phenyl ester, parabrom cinnamic acid (orthobromphenyl) ester, 2,6-dichlorocinnamic acid (2 ', 4'
-Dichlorophenyl) ester, cinnamic acid benzyl ester, cinnamic acid (orthochlorobenzyl) ester, cinnamic acid (parachlorobenzyl) ester, cinnamic acid (orthobrombenzyl) ester, cinnamic acid (parabrombenzyl)
Ester, cinnamic acid (metabromobenzyl) ester, orthochlorocinnamic acid benzyl ester, parabromocinnamic acid (orthobromobenzyl) ester, 2,4-dichlorocinnamic acid (2 ', 4'-dichlorobenzyl) ester, cinnamic acid cyclohexyl Examples thereof include esters, orthochlorocinnamic acid ethyl ester, octochlorocinnamic acid phenyl ester, parabromocinnamic acid cyclohexyl ester, and metachlorocinnamic acid (octochlorobenzyl) ester.

The optical lens of the present invention can be obtained by polymerizing one kind or two or more kinds of the cinnamic acid ester. Also,
It is also possible to obtain the cinnamic acid ester by radical copolymerization with one or more radically polymerizable vinyl monomers or crosslinkable vinyl monomers.

Radical-polymerizable vinyl monomers or crosslinkable vinyl monomers include styrene, p-methylstyrene, p-
Chlorostyrene, o-chlorostyrene, p-bromostyrene, o-bromostyrene, p-divinylbenzene, m
-Divinylbenzene, divinylbiphenyl, vinyl acetate, vinyl propionate, vinyl benzoate, methyl methacrylate, butyl methacrylate, methyl acrylate, ethyl acrylate, phenyl methacrylate, phenyl acrylate, benzyl methacrylate, benzyl acrylate, bromphenyl methacrylate, acrylonitrile, Methacrylonitrile, ethylene glycol dimethacrylate, diethylene glycol dimethacrylate, ethylene glycol diacrylate, diethylene glycol diacrylate, dipropylene glycol dimethacrylate, bisphenol A dimethacrylate,
2,2-bis (4-methacryloyloxyethoxyphenyl) propane, 2,2-bis (4-acryloyloxyethoxyphenyl) propane, diallyl phthalate,
Examples include diallyl tetrachlorophthalate, diallyl isophthalate, diethylene glycol bisallyl carbonate, diallyl tetrachlorophthalate, and the like. At least one type of crosslinkable polymer is used for the purpose of improving the solvent resistance and heat resistance of the resulting resin. It is preferable to select a functional vinyl monomer. The copolymerization composition ratio of the radically polymerizable vinyl monomer or the crosslinkable vinyl monomer to the cinnamic acid ester of the present invention is preferably in the range of 1000 to 1 part by weight relative to 100 parts by weight of the cinnamic acid ester, and further 50
The range of 0 to 10 parts by weight is preferred. In this case, 1000
If it exceeds 1 part by weight, the refractive index of the obtained lens is remarkably lowered, and if it is less than 1 part by weight, the effect of the copolymerization of the radically polymerizable vinyl monomer or the crosslinkable vinyl monomer is not sufficient.

As the polymerization initiator used for polymerizing the polymer or copolymer according to the present invention, one selected from organic peroxides and azo compounds having a selected 10-hour half-life temperature of 100 ° C. or lower.
One kind or two or more kinds are used.

Examples of such a polymerization initiator include benzoyl peroxide,
Diisopropyl peroxydicarbonate, tertiary butyl peroxy 2-ethylhexanoate, tertiary butyl peroxypivalate, tertiary butyl peroxy neodecanoate, tertiary butyl peroxydiisobutyrate, lauroyl peroxide, azobisisobutyl nitrile, etc. Can be mentioned. The amount of the polymerization initiator used is preferably 10% 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 lens of the present invention by the above-mentioned polymerization or copolymerization, a method of directly charging the composition obtained by adding a polymerization initiator to the monomer raw material into a desired mold and heating and curing the system is used. Processing after 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 or the like at appropriate times. Further, after the polymerization initiator is added to the raw material monomer, it is slightly polymerized or copolymerized at a predetermined temperature (30 to 70 ° C.) in advance, and then charged into a desired mold and cured by heating to complete the polymerization. It is also possible to take a method.

The temperature for heat curing varies depending on the polymerization initiator used, but is preferably in the range of 30 to 100 ° C., more preferably about 10 hours half-life temperature of the polymerization initiator used. Further, the curing temperature can be raised at appropriate times for the purpose of shortening the curing time and treating the unreacted monomers and the polymerization initiator. In this case, the total time required for curing is about 10 to 48 hours.

<Effects of the Invention> The optical lens of the present invention containing a cinnamic acid ester as a resin component has a high refractive index of n _D of 1.60 or more and an Abbe number of 30 or more, and is colorless and transparent, and shrinks during molding polymerization. Small rate,
It is possible to provide an optical lens in which the drawbacks of conventional optical lenses, such as excellent heat resistance, are improved.

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

Various physical properties were measured by the methods described below.

Refractive index, Abbe number ··· Abbe refraction system Specific gravity · · Resin weight divided by resin volume by water substitution method.

Polymerization shrinkage: The raw material is the specific gravity of the monomer composition (ρ _M ),
It was calculated from the specific gravity (ρ _P ) of the cured resin according to the formula (1-ρ ₁ / ρ ₂ ).

Heat resistance ···································· The resin that does not show any change in deformation, coloring, etc. after being left in a dryer at 150 ° C for 2 hours was rated as ◯ and unacceptable as x.

Example 1 A raw material mixed monomer consisting of 15 g of cinnamic acid phenyl ester, 10 g of orthochlorostyrene and 2.5 g of 2,2-bis (4-acryloyloxyethoxyphenyl) propane was heated to 60 ° C. and replaced with nitrogen.

While maintaining the raw material mixed monomer at 60 ° C., as a radical polymerization initiator, tertiary butyl peroxy (2-
0.75 g of ethyl hexanoate) was added. The monomer composition was charged into two glass molds (using a silicon gasket) and placed in a constant temperature bath at 70 ° C. under a nitrogen stream for 24 hours.
After curing for an hour and annealing at 100 ° C. for 2 hours, the cured lens was taken out from the mold and evaluated by the above-mentioned physical property test.

Examples 2 to 6 In the same manner as in Example 1, raw material monomers having various compositions were prepared with a predetermined radical initiator and curing conditions to prepare cured lenses. The results are shown in Table 1.

As a comparative example, the results of carrying out diethylene glycol bisallyl carbonate and styrene are also shown.

As is clear from the above results, in each of the examples of the present invention, the refractive index shows a value in the range of 1.612 to 1.638, and the Abbe number, the shrinkage ratio, and the heat resistance are excellent, but the refractive index in the comparative example is It can be seen that it does not reach 1.6 and the shrinkage ratio is large, that the comparative example 1 has a large Abbe number and that the comparative example 2 has poor heat resistance. Each of the lenses obtained in the examples of the present invention had a visible light transmittance of 90% or more, and was suitable as an optical lens.

Continuation of front page (56) References JP-A-50-1721 (JP, A) JP-A-53-101088 (JP, A)

Claims (3)

[Claims] 1. The following general formula (In the formula, A is Or R, X represents a halogen atom, and l and m
Is an integer of 0 or 1 or more and 5 or less, and R is a carbon number of 3 to 1.
An optical lens made of a resin obtained by polymerizing or copolymerizing a cinnamic acid ester represented by 2). 2. The optical lens according to claim 1, wherein the copolymerization component is a radically polymerizable vinyl monomer or a crosslinkable vinyl monomer. 3. The following general formula (In the formula, A is Or R, X represents a halogen atom, and l and m
Is an integer of 0 or 1 or more and 5 or less, and R is a carbon number of 3 to 1.
A cinnamic acid ester represented by 2), or a mixture of a copolymerizable vinyl monomer copolymerizable with the cinnamic acid ester and the cinnamic acid ester.
An optical lens characterized by being placed in a predetermined mold and cured by heating in the presence of one or more polymerization initiators selected from organic peroxides and azo compounds having a time half-life temperature of 100 ° C. or less. Manufacturing method.