JPH01168712A - Resin for optical material - Google Patents

Abstract

PURPOSE:To obtain the title resin having excellent moisture resistance, heat resistance, thermal stability and low birefringence, by polymerizing an esterification product of tricyclodecane-and/or pentacyclopentadecanedimethanol and (meth)acrylic acid and a specified (meth)acrylate. CONSTITUTION:1 mole of tricyclodecanedimethanol and/or pentacyclopentadecanedimethanol is esterified with 2 moles of a mixture of methacrylic acid with acrylic acid to obtain a mixture of di(meth)acrylate (A) as the reaction product. 100 pts.wt. ethylenically unsatd. monomer consisting of 50-99wt.% component A and 50-1wt.% (meth)acrylate (B) of formula I (wherein R1 is a group of formulas II and III; R2 is H, CH3) is polymerized in the presence of 0.01-20 pts.wt. radical initiator (e.g., benzoyl peroxide) in air or in an inert gas at 0-150 deg.C.

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 superimposed to form a resin.

[Conventional technology]

BACKGROUND ART One type of optical equipment that is rapidly developing in the field of information processing is one that uses optically readable discs (video discs, memory discs, digital audio discs, etc.).

For example, optical discs have extremely high recording density and excellent reproduced image and sound quality, and are therefore becoming widely used for recording and reproducing images and sounds, and for recording and reproducing large amounts of information.

The materials conventionally used for such discs have their advantages and disadvantages, and it cannot be said that a fully satisfactory material has yet been proposed. For example, inorganic glass, polymethyl methacrylate resin, and polycarbonate resin have been put into practical use as memory disk materials, but there is no material that satisfies all of the requirements such as heat resistance, birefringence, weight reduction, and economic efficiency, especially rewritable type. Substrate materials for optical discs are a major hindrance to practical application.

The present inventors have already found a resin with high heat resistance and low birefringence, such as bis(oxymethyl)tricyclo(
Radical polymer of 5,2,1,0''-)decane di(meth)acrylate (JP-A-62-225508)
and bis(oxymethyl]pentacyclo(R2,1,1
, 1j04. ? 01,11) We have proposed a radical polymer of pentadiene di(meth)acrylate (Japanese Patent Application No. 7292/1982) and found that it can satisfy a high degree of heat resistance, thermal safety, and low birefringence.

[Problem that the invention seeks to solve]

However, from the standpoint of practical durability as an optical disc with a laminated recording layer, that is, maintenance of the CZN ratio, record preservation, etc., the substrate is required to have extremely high environmental resistance (humidity resistance). From this point of view, there is a need for a (meth)acrylate-based resin for optical materials that satisfies the even higher performance required for resin materials for disks.

[Means to solve the problem]

The present invention provides a resin for optical materials comprising a radical polymer of an ethylenically unsaturated monomer, in which the ethylenically unsaturated monomer is acrylic acid and A di(meth)acrylate mixture obtained by esterifying a mixture of 2 moles of methacrylic acid has a weight of 50 to 99%, and the following formula (1
) It is an object of the present invention to provide a resin for optical materials having good moisture resistance, heat resistance, optical properties, and mechanical properties, which is characterized by being composed of 1 to 50% by weight of (meth)acrylate represented by It is something.

Bird ■ is also 5-CHx-OC-C=CH2 (1) R2 represents H or a CHA group. ) The di(meth)acrylate mixture used in the present invention can be synthesized by a known method. For example, 1 mol of tricyclodecane dimethanol and/or pentacyclopentadecane dimethanol is mixed with 2 mol of a mixture of methacrylic acid and acrylic acid.
It can be obtained by dehydration and esterification in moles as shown in the following formula (2).

Here, bird, R2 is H or 0M3 group, bird is a compound of P
(abbreviated as CPDDM-MA) t-represented.

The (meth)acrylate monomer represented by the uninvented formula (1) is tetracyclododecenemethanol and/or tetracyclododecanemethanol (hereinafter collectively referred to as T).
It is an esterification product of (abbreviated as ECDD-M) and (meth)acrylic acid.

TECDD-M is obtained by subjecting an adduct of cyclopentadiene and allyl alcohol to a cyclopentadiene reaction, and further reacting with hydrogen using a hydrogenation catalyst (for example, baladicum carbon) as necessary. TECDD-M t- can also be obtained by reducing sweetened tetracyclododecanecarbaldehyde using cyclopentadiene and acrolein. See formula (3) below.

XneyCH,O)I or -CHO The (meth)acrylate n represented by formula (1) used in the present invention is composed of 1 mol of TECDIJ-M and (meth)acrylic! It is obtained by ft-dehydration esterification of about 1.0 to 1.5 moles. That is, these raw materials are placed in a reaction vessel,
Add a reaction solvent that also serves as a dehydrating agent, an esterification catalyst, and if necessary a polymerization inhibitor, and perform esterification at a reaction temperature of 50 to 200°C (preferably 80 to 150°C) under air or inert gas. . Examples of the polymerization inhibitor used for inhibiting radical polymerization include phenols such as hydroquinone and hydroquinone methyl ether, quinones such as benzoquinone and diphenylbenzoquinone, phenothiazine, and copper salts. The amount of these heavy @-stoppers used is 0.001 to 10 parts by weight, preferably 0.1 to 10 parts by weight, per 100 parts by weight of (meth)acrylic acid.
It is 5 parts by weight. As a dehydration synergist, n-hexane,
Cyclohexane, benzene, toluene and trichloroethylene l' are preferably used.

As the esterification catalyst, common esterification catalysts such as diabolic acid, hydrochloric acid, phosphoric acid, p-toluenesulfonic acid, and cationic father-converted 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 (e.g. in the form of lower alcohol esters). This also includes cases where esters are produced by transesterification.

Polymerization method The resin for optical materials according to the present invention comprises the above-mentioned ethylenically unsaturated monomer mixture, that is, the above-mentioned di(meth)acrylate mixture. ! It is obtained by radical polymerization of a mixture of 50 to 99 parts by weight of L'CDDM-MA and/or PCPDDM-MA and 1 to 50 parts by weight of the (meth)acrylate represented by formula (1). If the amount of (meth)acrylate represented by formula (1) is 50 parts by weight or more, the water resistance will improve, but the heat resistance will be significantly inferior. Therefore, in order to exhibit high heat resistance and low water absorption, the amount is preferably 20 to 40 parts by weight.

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 an ethylenically unsaturated monomer mixture and heated, and a method in which a photosensitizer is blended and exposed to ultraviolet light Radical copolymerization can be carried out by irradiation with electron beams, radiation, etc. Examples of radical initiators used in this case include five-organic peroxides such as benzoyl peroxide, diisopropyl peroxide, tertiary butyl peroxypiperate, and lauroyl peroxide, and azoyl peroxides such as azoisobutyronitrile. compounds, photosensitizers such as benzophenone, benzoin ethyl ether, benzyl, acetophenone, anthraquinone,
Radical initiators such as sulfurized products such as diphenyl sulfite and thiocarbamate can be used. The amount of radical initiator used is 0.0 parts per 100 parts of the monomer mixture.
It ranges from 1 to 20 parts, more preferably from 0.01 to 10 parts.

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

Since the monomers that characterize the present invention include diethylenically unsaturated monomers, the resulting polymers are crosslinked and cannot be shaped into shapes by means involving melting. Therefore, it is preferable to carry out the polymerization by so-called "cast polymerization" to obtain the resulting polymer in the form of plates or blocks.

〔Example〕

The present invention will be explained in more detail with reference to experimental examples below.

Parts in the following experimental examples are based on parts by weight qbFi.

Further, various physical properties of the resins obtained in the Examples were measured by the following test methods.

(1) Light transmittance: Measure the light transmittance of 500 parts m with a two-spectrophotometer (2) Birefringence: Measure with a polarizing microscope (3) Saturation water absorption"a: Saturation when immersed in water at 60°C Water absorption rate (4) Elastic modulus: Dynamic mechanical analysis (
DMA) by side legs (storage modulus at 50°C) (5) Heat resistance: Same as above, peak temperature of loss modulus Production example 30 equipped with a stirrer, thermometer, nitrogen inlet tube, and water separator
In a 0-4-eye flask, add 0.27 moles (52 parts) of tetracyclododecane methanol and 39 moles (3 parts) of methacrylic acid.
4 parts) Toluene (75 parts), p-toluenesulfonic acid hydrate (2.5 parts) and copper powder (0.02 parts) were simultaneously charged, and the reaction temperature was 90 to 120°C for 2 hours under a nitrogen gas atmosphere. Made it react.

After the reaction was completed, the mixture was cooled and the excess acid was neutralized with an aqueous potassium carbonate solution.The organic layer was further washed with pure water three times, and the toluene was distilled off using an evaporator to obtain 67 parts of the target methacrylate.

Example 1 PCPDDM/MA was added to 20 parts of the monomer obtained in the production example.
80ftB, benzoyl peroxide (0.5 parts) 1
-Hydroxycyclohexylphenylketone (Ciba Geigy's product name Irgacure 184) (0,
3 parts) was added, heated and stirred evenly, and poured into a mold made of a glass plate and a silicone rubber spacer. After the ilt irradiation, it 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 40 parts of monomer obtained in the production example in Example 1 PCPDD
A cured product was obtained in exactly the same manner except that 60 parts of M-MA was used. Table 1 shows the physical property measurement results of the cured product.

Example 3 A cured product was obtained in exactly the same manner as in Example 1 except that all 80 parts of TCDDM-MA was used instead of 80 parts of PCPDDM-MA. Table 1 shows the physical property measurement results of the cured product.

Example 4 40 parts of the monomer obtained in the production example in Example 2 and TCDD
A cured product was obtained in exactly the same manner except that 60 parts of M-MA was used. Table 1 shows the physical property measurement results of the cured product.

Comparative Examples 1 to 4 In Example 1, each monomer was PCPDDNI.
MA 100 parts (Comparative Example 1), TCDDM-MA 10
0 body and 20 parts of PCPDDM-MA (Comparative Example 2)
and 80 parts of the monomer obtained in the production example and TCDDM-MA 2
A cured product was obtained in exactly the same manner except that 0 part (Comparative Example 3) was used. Table 1 shows the physical property measurement results of the cured product.

(Margin below)

Claims (1)

[Scope of Claim] A resin for optical materials comprising a radical polymer of an ethylenically unsaturated monomer, in which the ethylenically unsaturated monomer is added to 1 mole of tricyclodecane dimethanol and/or pentacyclopentadecane dimethanol. 50 to 99% by weight of a di(meth)acrylate mixture obtained by esterifying a mixture of 2 moles of acrylic acid and methacrylic acid and 1 to 50% by weight of a (meth)acrylate represented by the following formula (1)
A resin for optical materials characterized by comprising: ▲There are mathematical formulas, chemical formulas, tables, etc.▼ (1) (In the formula, R_1 is ▲There are mathematical formulas, chemical formulas, tables, etc.▼ or ▲There are mathematical formulas, chemical formulas, tables, etc.▼, R_2 indicates H or CH_3 group. )