JPS60124605A - Optical material - Google Patents

Abstract

PURPOSE:To obtain an optical material having low hygroscopicity, low dispersion, a high refractive index and low shrinkage during cast polymerization, by incorporating a radical polymer containing specified bromine-containing cyclopentadiene derivatives as principal monomer components. CONSTITUTION:An optical material containing a radical polymer containing compounds of formulas I and II as principal monomer components. In the formulas, R1 is H or methyl, R2 is H or a 1-3C alkyl, n is 1-2, m is 1-4, R3 is a 1-5C alkylene, or alkylene oxide, n is 1-2, and m is 1-4. The compound of formulas I or II can be easily obtained by brominating a hydroxy compound obtained by reacting dicyclopentadiene or tricyclopentadiene with water or a diol in the presence of an acid catalyst and esterifying the brominated hydroxy compound with (meth)acrylic acid. Examples of the compounds of formulas I and IIinclude compounds of formulas III and IV.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an optical material containing a radical polymer containing a bromine-containing cyclopentadiene derivative as a main monomer.

In general, plastic optical materials have advantages over glass materials, such as being lighter, having higher impact resistance, no need for polishing, ease of mass production, and the ability to mass produce aspherical lenses. .

However, plastic optical materials have drawbacks such as a narrow range of refractive index selection and high hygroscopicity compared to glass materials, and these points have traditionally prevented the use of plastic optical materials. This was a factor that inhibited the especially,
A plastic optical material with low dispersion and high refractive index has not been available in the past. For example, diethylene glycol bisallyl carbonate is used as a lens for glasses under the name CR39, but it has drawbacks such as a lower refractive index and lower heat resistance than conventional lens glasses.

The present invention solves the above-mentioned drawbacks, and provides an optical material having low shrinkage during cast polymerization, low hygroscopicity, and low dispersion and high refractive index. or (It) (wherein R1 is hydrogen or a methyl group,
Karasu is hydrogen or an alkyl group having 1 to 3 carbon atoms, R5
is an alkyl group or alkylene oxide group having 1 to 5 carbon atoms, sb is an alkyl group having 1 to 5 carbon atoms, and m is an integer of 1 to 4. There are optical materials obtained by this method.

The optical material of the present invention uses a specific compound represented by the above general formula (1) or (11) as an acrylate monomer containing an olefinic group, which is different from conventional ones. It can significantly improve polymerization shrinkage properties and moisture absorption resistance, and has the characteristics of having the low dispersibility of methyl methacrylate and the high refractive index of styrene and polycarbonate.

The compound represented by the above general formula (I) or 1) as the main monomer used in the optical material of the present invention includes dicyclopentadiene and tricyclopentadiene,
It can be easily obtained by brominating a hydroxy compound obtained by reacting with water or a diol under an acid catalyst and then esterifying it with methacrylic acid or acrylic acid. For example, a compound represented by the following formula can be obtained.

r In the present invention, a radical polymer containing a compound represented by the general formula (1) as a main monomer component, and a radical polymer having the compound represented by the general formula (II) as a main monomer component;
) may be blended with a radical polymer whose main monomer component is a compound represented by:

Other monomers can be used in combination with the above-mentioned bromine-containing cyclopentadiene derivative, if necessary. The monomer is not particularly limited as long as it is a monomer component that is radically polymerizable and does not impair the transparency of the polymer, but especially esters of acrylic acid or methacrylic acid such as methyl methacrylate, cyclohexyl methacrylate, and adamantyl methacrylate. , aromatic vinyl compounds such as styrene, bromostyrene, vinylnaphthalene,
Preferred are esters of polyhydric alcohols such as ethylene glycol, diethylene glycol, and pentaerythritol and methacrylic acid, alkyl allyl ethers such as allyl diglycol carbonate, diallyl phthalate, diallyl isophthalate, and the like. The type and content of monomers used in combination can be selected taking into consideration the refractive index, dispersion rate, heat resistance, etc. required for the optical material, but from the viewpoint of shrinkage during cast polymerization, preferably Above - Sanshiki (1)
Or, the amount used is usually 70 parts by weight or less, preferably 70 parts by weight or less, based on (up to) parts by weight of the compound (01).

The compound represented by the above general formula (I) or (11) is
Polymerization is carried out in the presence of a radical polymerization initiator. Examples of radical polymerization initiators used in this case include conventional peroxides such as benzoyl peroxide, diisopropyl peroxydicarbonate, methyl ethyl ketone peroxide, lauroyl peroxide, other peroxides, and azo compounds such as azobisisobutyronitrile. A radical polymerization initiator can be used.

The method of polymerizing the compound represented by the above general formula (1) or general formula (11) is not particularly limited, and for example, bulk polymerization, suspension polymerization, solution polymerization, radiation polymerization, ultraviolet polymerization, etc. may be used. I can do it.

The molding method for producing the optical material of the present invention is not particularly limited, and methods such as pouring into a mold and polymerizing and curing, injection molding, compression molding, and the like can be employed.

During the polymerization, additives such as a mold release agent, an ultraviolet absorber, an antioxidant, a coloring inhibitor, an antistatic agent, a fluorescent dye, and various stabilizers may be added as necessary.

The optical material of the present invention has low dispersion, high refractive index, little shrinkage during cast polymerization, and extremely low hygroscopicity.

The optical material of the present invention includes, for example, so-called lenses for eyeglasses, still cameras, video cameras, telescopes, and sunlight concentrators, prisms, light guide elements such as optical waveguides, video discs, The present invention will be explained in more detail by showing examples below.

Example 1 Monobromotricyclo(5,2%1, OJ&...>6]f
A monomer solution prepared by dissolving 0.5 weight of azobisisobutyronitrile in diltrimethacrylate was poured into a mold made of two glass plates and a gasket, and heated at ℃ for 3 hours under a nitrogen atmosphere. After further heating and curing at 100° C. for 3 hours, the mold was released to obtain a polymer (A).

Example 2 Dibromotricyclo(5,211%0'')decyl methacrylate was polymerized in the same manner as in Example 1 to form a polymer (B
) was obtained.

Example 3 Tribromotricyclo(5,2,1,02+')decyl methacrylate was polymerized in the same manner as in Example 1 to obtain a polymer (C).

Example 4 Five secrets of dibromotricyclo[:5.2.1 bo”)decyl methacrylate/methyl methacrylate (wt%)
The mixed monomers were polymerized in the same manner as in Example 1 to obtain a polymer (D).

Example 5 Diglome tricyclo(,5,2,1% oL6) decoxydiethyl methacrylate was polymerized in the same manner as in Example 1 to obtain a polymer (E).

Comparative Example 1 A monomer prepared by dissolving 0.1 weight percent of azobisisobutyronitrile in methyl methacrylate was polymerized in the same manner as in Example 1 to obtain a polymer (F).

For the polymers (A) to (E) obtained in Examples 1 to 5, the refractive index, dispersion rate, light transmittance, surface hardness, water absorption rate, heat distortion temperature, and polymerization shrinkage rate were measured. Table 1 shows the results.
Shown below.

At the same time, for comparison, the polymer obtained in Comparative Example 1 (F
) were also tested in the same manner and the results are shown in Table 1 as a comparative example.
Shown below.

Table-1 Refractive index/dispersion rate: Measured using Atsube's refractometer. contact liquid
Use methylene iodide.

Light transmittance: Measured on a 2JIB thick test piece using a haze meter Hardness: JIS-54oo Pencil hardness & heat distortion temperature: VICAT

Claims (1)

[Claims] (1) General formula (1) (In the formula, R1 is hydrogen or a methyl group, R1 is hydrogen or an alkyl group having 1 to 3 carbon atoms, n is an integer of 1 to 2, and m is 1 to 4) or the general formula ω) (wherein, R1 is hydrogen or a methyl group, and R2 is hydrogen or an alkyl group having 1 to 3 carbon atoms, sJp
, Rs is an alkylene group or alkylene oxide having 1 to 5 carbon atoms, n is an integer of 1 to 2, and m is an integer of 1 to 4). Materials for use.