JPH01261408A - Resin for optical material - Google Patents

Abstract

PURPOSE:To attempt to improve optical characteristics, heat resistance and water resistance, by using a radical copolymer consisting of a (meth)acrylate having a tetracyclododecane(dodecene) group and a polyfunctional alicyclic monomer as a constitutional component. CONSTITUTION:The title resin for an optical material is a polymer obtd. by compounding a monomer consisting of 50-98wt.% (meth)acrylate of tetracyclododecane and/or tetracyclododecene of formula I and/or formula II (wherein R and R' are each H or CH3) and 50-2wt.% polyfunctional alicyclic monomer, e.g., tetracyclododecanedimethanol di(meth)acrylate, a photosensitizer, a radical-polymn. initiator, etc., and irradiating the compd. with ultraviolet rays, electron beams, etc. This resin is especially usable for applications where low birefringence, high heat resistance and low water absorbing property are required, such as rewritable and erasable optical disc bases.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a resin for optical materials comprising a radical polymer of ethylenically unsaturated monomers. Specifically, the present invention relates to an optical resin material having a main feature in an ethylenically unsaturated monomer to be polymerized to form a resin.

[Conventional technology]

In recent years, the demand for glass optical elements such as lenses and optical disk substrates has rapidly increased, and various resins have been developed and are being offered on the market.

Among them, polymethyl methacrylate (PMMA) is a representative
) Resins are used in a wide range of applications due to their excellent optical properties, such as high transparency and low birefringence. However, on the other hand, the environment in which paper is used has become more severe, and improvements in heat resistance, moisture resistance, etc. are strongly desired, and various improved techniques have been disclosed to solve these demands. For example, polycyclohexyl methacrylate and its copolymers have been attempted to reduce water absorption by upgrading the alcohol residue of methacrylic acid ester (increasing the number of carbon atoms), but they simultaneously improve heat resistance and low water absorption. It is difficult to
each issue, etc.). In addition, as one method for improving heat resistance, a technique using cast polymerization using methyl methacrylate and crosslinkable hexamer has been disclosed (Japanese Unexamined Patent Application Publication No. 1983-1982).
83213, 41716, etc.). Although this technology may improve thermal properties such as heat distortion temperature and water absorption, it cannot make any major improvements.

[Problem to be solved by the invention]

As mentioned above, all of the materials proposed so far have problems in optical properties, hygroscopicity, and heat resistance, and cannot be said to be sufficient. In particular, rewritable and erasable i+s (
In order to use it in applications requiring low birefringence, high heat resistance, and low water absorption, such as BJi optical disk substrates, it is necessary to further improve the performance. The present invention aims to solve the above problems and provide a resin for optical materials having excellent performance.

[Means to solve the problem]

In order to solve the above problems, the inventors of the present invention have conducted extensive research and developed an optical material with excellent optical properties, heat resistance, and water resistance as shown below.

That is, the present invention provides - a compound represented by the following formula (1) and/or
The present invention provides a resin for optical materials obtained by radical polymerization of a single-seam mixture consisting of ~50% by weight.

O R' (In the formula, R and R' represent a hydrogen atom or a methyl group.) Compounds (1) and (II) used in the present invention are tetracyclododecenemethanol or tetracyclododecanemethanol (hereinafter referred to as It is a product obtained by esterifying 1 mol of (generally abbreviated as TECDD-M) with 1 mol of (meth)acrylic acid.

TECDD-M is easily obtained using cyclopentadiene. That is, it is obtained by reacting an adduct of cyclopentadiene and allyl alcohol with cyclopentadiene.

Further, by reacting with hydrogen using a catalyst (for example, palladium on carbon), a hydrogenated product can be obtained. In addition, by reducing tetracyclododecenecarbaldehyde synthesized using cyclopentadiene and acrolein, TE
CDD-M can be obtained.

The reaction between TECDD-M and (meth)acrylic acid is TE
meth)acrylic acid per mole of CDDMI from 1.0 to 1.
The reaction is carried out by dehydration and esterification using 5 mol. Specifically, these raw materials are charged into a reaction vessel, a reaction solvent that also serves as a dehydrating agent, an esterification catalyst, and a polymerization inhibitor are added as necessary, and the reaction temperature is increased to 50 to 200°C (preferably 80 to 80°C). Esterification is carried out at 150° C.) under air or inert gas.

At this time, as the polymerization inhibitor, for example, hydroquinone, hydroquinone monomethyl ether natophenols, benzoquinone, which is used to prevent radical polymerization,
Examples include quinones such as diphenylbenzoquinone, phenothiazine, and copper salts. The fecal discharge of these polymerization inhibitors is (meth)acrylic! i! o against 100 heavy European divisions,
o o i to 10 parts by weight, preferably 0.1 to 5 parts by weight. As the dehydration entrainer, n-hexane, cyclohexane, benzene, toluene, trichloroethylene, etc. are preferably used.

As the esterification catalyst, common esterification catalysts such as sulfuric acid, hydrochloric acid, phosphoric acid, p-toluenesulfonic acid, and cationic exchange resins can be used as appropriate.

After the esterification reaction is completed, the reaction solution is washed with an aqueous alkaline solution and water, the aqueous layer is separated, and the organic layer is dehydrated under reduced pressure to remove the entrainer.

Esterification here is not necessarily meant to be limited to dehydration reactions in which both reactants are used in the form of alcohol and carboxylic acid, but also in the form of their functional derivatives (for example in the form of lower alcohol esters). This also includes cases where esters are produced by transesterification.

The above-mentioned compound (1) is an alicyclic poly(meth)acrylic acid ester used in combination with the above compound (1), and is a heptamer having two or more ethylenically unsaturated groups.

Examples of the alicyclic structure include the following.

H3 Specifically, heptacycloeicosan dimethanol cyacrylate, pentacyclopentadecane dimethanol diacrylate, tetracyclodecane dimethanol diacrylate, dimethacrylate similar to these, (meth)
Acrylate, heptacycloeicosane diacrylate, pentacyclopentadecane diacrylate, tetracyclodecane diacrylate, hexacycloheptadecane dimethanol diacrylate, tetracyclododecane dimethanol diacrylate, bicyclohebutane dimethatool diacrylate, hexacyclohepta Decane diacrylate Tetracyclododecane diacrylate, Bicyclohebutane diacrylate, 2.27-bis(4'-
Examples include (β-methacloyloxy)cyclohexyl]propane diacrylate, cyclohexane dimetatool diacrylate, cyclohexane diacrylate, and similar dimethacrylates and di(meth)acrylates. Among these, in order to maintain high heat resistance and low water absorption, pentacyclopentadecane diacrylate, tetracyclodecane dimethanol diacrylate, tetracyclodecane dimethanol diacrylate, etc. are preferred.

Radical polymerization techniques are well known, such as a method in which a radical initiator such as an organic peroxide or an azo compound is blended into a polymerizable composition and heated;
Radical copolymerization can be carried out by irradiation with electron beams, radiation, etc.

Examples of radical initiators used in this case include organic peroxides such as benzoyl peroxide, diisopropyl peroxide, tertiary pteroperoxybiparate, and lauroyl peroxide, azo compounds such as azoisobutyronitrile, and benzophenone. Radical initiators such as photomagnetic agents such as , benzoylethyl ether, benzyl, acetophenone and anthraquinone, and sulfur compounds such as diphenyl sulfite and thiocarbamate can be used.

The amount of the radical initiator used is in the range of 0.01 to 20 parts, more preferably 0.01 to 10 parts, per 100 parts of the acrylic compound represented by the above formula.

The method for radical copolymerization of the polymerizable composition of the present invention is preferably carried out at a temperature of 10 to 150°C in the atmosphere or in an inert gas.

It can be said that it is preferable to carry out the polymerization by so-called "cast polymerization" to obtain the resulting polymer in the form of a plate or a block.

Alternatively, the monomer can be prepolymerized in advance and then subjected to casting polymerization.

〔Example〕

The present invention will be explained in more detail by showing experimental examples below.

In addition, parts in the examples are parts by weight, and % is weight %. In addition, various physical properties were measured by the following test methods.

(11 Light transmittance Measure the light transmittance of 500 parts m with a dual spectrophotometer (2) Measure with a birefringence dual polarization microscope (3) Saturated water absorption = Saturated water absorption when immersed in water at 60°C (4) Elastic modulus: Measured by Dynabat Mechanical Analysis (DMA) (storage modulus at 50°C) (5) Heat resistance: Same as above at peak temperature of loss modulus Manufacturing example Stirring device, thermometer, nitrogen introduction tube, 30 with water separator
In a 0 m Yotsuro flask, add 0.27 mol (52 parts) of tetracyclododecane methanol and 0 methacrylic acid with Nu.
．． 39 mol (34 parts)) toluene (75 parts) p-toluenesulfonic acid-hydrogen (z, s parts) copper powder (0.02 parts) were simultaneously charged, and the reaction temperature was 90 to 12 mol under nitrogen gas atmosphere.
The reaction was carried out at 0°C for 2 hours. After the reaction is completed, cool the excess acid and neutralize it with an aqueous solution of potassium carbonate.
After washing twice, toluene was distilled off using an evaporator to obtain 67 parts of methacroyloxymethyltetracyclododecane.

Example 1 TCD-MA (tetracyclododecane methanol di(meth)acrylate) was added to 70 parts of the monomer obtained in the production example.
30 parts, benzoyl peroxide (B, P, 0)
Add 0.5 parts of Irgacure 184 (manufactured by Chipa Geigy, photosensitizer), mix uniformly with stirring, and pour into a mold consisting of a glass plate and a silicone rubber spacer. After irradiating with ultraviolet rays, the mixture was held at 150° C. for 2 hours to perform polymerization, and then taken out from the mold to obtain a cured product. Table 1 shows the physical property measurement results of the cured product.

Example 2 60 parts of the monomer obtained in the production example in Example 1 and TCD-
A cured product was obtained in exactly the same manner except that 40 parts of MA was used.

Example 3 70 parts of the monomer obtained in the production example in Example 1, 2.2'
A cured product was obtained in exactly the same manner except that 30 parts of -bis(4'-(β-methacroyloxy)cyclohexyl)propane was used.

Comparative example 1 Implementation? A cured product was obtained in exactly the same manner as in IJ 1 except that 30 parts of 1,6-hexanediol diacrylate was used instead of 30 parts of TCL).MA.

Comparative Example 2 A cured product was obtained in exactly the same manner as in Example 1, except that 70 parts of cyclohexyl methacrylate was used instead of 70 parts of the monomer obtained in Production Example.

Comparative Example 3 In Example 1, MM was used instead of 30 parts of TCD-MA.
A cured product was obtained in exactly the same manner except that 70 parts of A (syrup) was used.

The physical property measurement results of the cured product are summarized in Table 1.

(Margin below)

Claims (1)

[Claims] (1) In a resin for optical materials comprising a radical polymer of an ethylenically unsaturated monomer, the monomer has the following formula [I],
A resin for optical materials comprising 50 to 98% by weight of the compound represented by [II] and 50 to 2% by weight of an alicyclic polyfunctional monomer. ▲There are mathematical formulas, chemical formulas, tables, etc.▼[I] ▲There are mathematical formulas, chemical formulas, tables, etc.▼[II] (In the formula, R and R' represent a hydrogen atom or a methyl group.)