JPS63175010A - Resin for optical material - Google Patents

Abstract

PURPOSE:To provide a resin composed of a radically polymerized product of ethylenic unsasturated monomers composed mainly of a specific di(meth)acrylate mixture, and having extremely excellent moisture resistance in addition to high heat-resistance, thermal stability and mechanical characteristics. CONSTITUTION:The objective resin for optical material is composed of a radically polymerized polymer of an ethylenic unsaturated monomer composed mainly of a di(meth)acrylate mixture produced by esterifying 1mol. of pentacyclopentadecane dimethanol with 2mol. of a mixture of acrylic acid and methacrylic acid. The molar ratio of methacrylic acid/acrylic acid in the (meth) acrylic acid mixture is preferably 0.5-2.5 and the esterification is carried out at 80-150 deg.C in the presence of a reaction solvent and an esterification catalyst. The obtained resin has a light-transmission of >=85%, a birefringence of <=1X10<-5>, heat-resistance of >=200 deg.C, thermal stability of >=250 deg.C and an elastic modulus of >=300kg/mm<2>.

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, it is one of the optical resin materials that have the main characteristic of being an ethylenically unsaturated monomer that can be polymerized into a resin. Some use digital audio discs, etc.).

For example, optical discs have extremely high recording density and excellent playback image and sound quality.
It is becoming widely used for recording and reproducing images and sounds, recording and reproducing large amounts of information, etc.

a1 Sokai Button] Conventionally, materials used for such discs have advantages and disadvantages, and it cannot be said that a fully satisfactory material has been proposed yet. For example, inorganic glass and polymethyl methacrylate resin are in practical use as memory disk materials, but inorganic glass has drawbacks such as being heavy and easily broken, and precision processing of the glass is expensive. On the other hand, polymethyl methacrylate resin has a fatal flaw as a material for optical equipment in that its low heat resistance and high hygroscopicity cause discs to warp easily, which can cause malfunctions.

Solution In order to solve the above-mentioned problems observed in polymethyl methacrylate resin, the present inventors have developed, for example, a radical polymer of 1,4-bis(methacroyloxymethyl)cyclohexane (Japanese Patent Laid-Open No. 61 -17661
8), a radical polymer of 24'-bis(4-(β-methacroyloxy)cyclohexyl)propane (
JP-A-61-190512) and a radical polymer of bis(oxymethyl)tricyclo(5,2,1,02.5]decane dimethacrylate (JP-A-61-1742)
Publication No. 08) etc. were proposed.

[Problem that the invention seeks to solve]

However, in order to respond to the increasingly sophisticated performance requirements for resin materials for disks accompanying technological advances, the present inventors first developed a high degree of heat resistance and thermal stability using a specific di(meth)acrylate compound. However, from the standpoint of maintaining the CZN ratio, recording preservation, etc., there are An extremely high degree of environmental resistance (moisture resistance, etc.) is now required for discs, and from this point of view, we have developed di(meth)acrylate-based optical materials that satisfy the even higher performance required for resin materials for discs. The purpose is to provide resin.

[Failure to solve the problem]

That is, the resin for optical materials according to the present invention is a resin for optical materials comprising a radical polymer of an ethylenically unsaturated monomer, in which the ethylenically unsaturated monomer is a di(meth) of a specific polyalicyclic diol. One mole of acrylate, ie, pentacyclopentadecane dimethanol (hereinafter abbreviated as PCPD-DM), is esterified with two moles of a mixture of acrylic acid and methacrylic acid. ↓It is characterized by being mainly composed of a di(meth)acrylate mixture.

In addition to its good heat resistance, thermal stability and mechanical stability, the particular di(meth)acrylate mixture radical polymers of the present invention have extremely high moisture resistance.

Synthesis of polyalicyclic diol The polyalicyclic structure described above is composed of a cyclopentadiene trimer. This trimmer ti,')'/p.

It is known that pentadiene can be easily synthesized by heating it in an autoclave (Japanese Unexamined Patent Publication No. 49-9-1999).
No. 9782, JP-A-49-100067, etc.). The trimer obtained is pentacyclo [9.2.1., 1,
8.02,7,09・13]Pentadecane-4゜11-
Diene (trimer ■) and pentacyclo [9゜2.1.1
"10 to 10.03,1!l) Pentadecane-5,1
It is a mixture of 2-dienes (trimer ■).

The dimethazole compound used in the present invention can be molded by oxysynthesis using the above-mentioned diene compound as a raw material. That is, PCPD-DM can be easily obtained by reacting cyclopentadiene trimer, -carbon oxide, and hydrogen with a cobalt complex as a catalyst under heat/pressure, followed by distillation isolation (Japanese Unexamined Patent Application Publication No. 1983-1992). -140940, etc.).

Synthesis of Monomer The monomer of the present invention is a compound obtained by esterifying 1 mole of the above PCPD-0M with 2 moles of a mixture of methacrylic acid and acrylic acid.

Here, esterifying 1 mole of PCPD-0M with 2 moles of a mixture of methacrylic acid and acrylic acid means that
First of all, it only means that the chemically theoretical amount of a mixture of methacrylic acid and acrylic acid, which is one of the reactants in the esterification reaction, is 2 moles; When an excess of the monomer (usually a cheaper or easier to remove monomer, in this case a mixture of methacrylic acid and acrylic acid) is used, or when the reaction is carried out in two steps, e.g. and methacrylic acid, and then add acrylic acid for further reaction, and the ester ratio does not necessarily mean that both reactants are used in the form of alcohol and carboxylic acid. It is not meant to be limited to dehydration reactions, but one or both may be used in the form of functional derivatives thereof, such as lower alcohols.
This also includes the case where the compound is used in the form of a ester and an ester is produced by transesterification.

Esterification can be carried out according to conventional methods and conditions, except that the reactants are specified and that the reactants and the resultant have ethylenically unsaturated bonds, so consideration must be given to preventing their polymerization.

Therefore, 1 mol of the dimethadol compound and about 2.0 to 2.6 mol of the (meth)acrylic acid mixture are subjected to an ester reaction. The molar ratio of methacrylic acid/acrylic acid in the (meth)acrylic acid mixture is about 0.25 to 4, preferably 0.25 to 4.
For unisterization, in which a concentration of about 5 to 2.5 is suitable, these raw materials are charged into a reaction vessel at the same time, a reaction solvent that also serves as a dehydrating agent, an esterification catalyst, and if necessary a polymerization inhibitor are added. Reaction temperature 50-200°C, preferably 80°C
The ester reaction is carried out in air or inert gas at ~150°C.

Examples of the polymerization inhibitor at this time include phenols such as hydroquinone and hydroquinone monomethyl ether, which are used to prevent radical polymerization, benzoquinone,
Examples include quinones such as diphenylbenzoquinone, phenothiazine, and copper salts. The most commonly used polymerization inhibitor is a mixture of methacrylic acid and acrylic acid.
0.001 to 10 double stitches to the C part, preferably 0.001 to 10 times.
1 to 5 direct parts. As the dehydration entrainer, n-hexane, n-pentane, cyclohexane, methylcyclohexane, benzene, toluene, xylene, trichlorethylene, tetrachloroethylene, methylchloroform, diisopropyl ether, etc. are preferably used.

Esterification catalysts include sulfuric acid, hydrochloric acid, phosphoric acid, boron fluoride Lp-)luenesulfonic acid, benzenesulfonic acid,
Common esterification catalysts such as 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.

Academic resin and its production polymerization The resin material for optical materials according to the present invention is obtained by subjecting the monomer containing the above-mentioned diethylenically unsaturated monomer as a main component to radical polymerization.

Here, the fact that this specific monoalpha form is the main component means that the monomer to be polymerized consists of only the above-mentioned specific monomer, as well as the case that the monomer to be polymerized consists only of the above-mentioned specific monomer. This means that a small amount of a saturated monolayer (for example, up to 60 weight percent based on the product mixture ERW) may be used in combination.

Monomers that can be used in combination include monomers that give a transparent polymer, such as styrene, lower alkyl methacrylate, formula % (R1 is H or CHs, R2 is a divalent group having 2 to 30 carbon atoms) A residue obtained by removing a hydroxyl group from an alcohol] (see JP-A No. 61-287913), and others.Specific examples include methyl methacrylate, cyclohexane (meth)acrylate, benzyl (meth)acrylate, neo Pentyl glycol (
Examples include meth)acrylate, butanediol (meth)acrylate, 414'-bis[β-(meth)acryloylethoxy]diphenylpropane, diethylene glycol bisallyl carbonate, diallyl phthalate, and the like.

In addition, "(meth)acrylate" in the above examples means both methacrylate and acrylate.

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 benzoyl peroxide, diisopropyl peroxide, tert-butyl peroxypivalate, and lauroyl peroxide. Organic peroxides such as oxides, azo compounds such as azoisobutyronitrile, photosensitizers such as benzophenone, pendine ethyl ether, benzyl, acetophenone, anthraquinone, diphenyl sulfite, thiocarbamates, etc. The total amount of radical initiator used is in the range of 0.01 to 20 parts, more preferably 0.1 to 10 parts, per 100 parts of the acrylic compound represented by the above general formula. It is.

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 an incubator or in an inert gas.

Since the monomer rk, which is a feature of the present invention, is a diethylenically unsaturated monomer, the resulting polymer is crosslinked and cannot be molded by means involving cracking.

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.

The resin thus obtained has a light transmittance of 85% or more,
It has a birefringence of I x 10-5 or less, heat resistance of 200°C or more, thermal stability of 250°C or more, and elastic modulus of 300 kg/- or more.

Actual test example In the following practical/experimental examples, parts are weight and percentages are based on electric resistance welding standards.

In addition, the various physical properties obtained in the actual test examples were measured by the following tests and tests.

(Measure the light transmittance at 500°C with an 11-light rA pass rate bispectrophotometer (2) Birefringence: Measure with a polarizing microscope (3) Heat resistance: Heat deformation test device according to ASTM-D-648 !
’t (4) Thermal stability: In air, using a thermogravimetric analyzer,
Measured at 0°C/min (5) Bending properties: J I S-K -691tK
(6) Water absorption rate: Measured according to JIS-691t (7) Saturated water absorption rate: When immersed in water at 60°C! Reference example of total water absorption rate Synthesis example of polycycloaliphatic diol A stainless steel autoclave with an internal volume of 500 R1 Nidicyclopentadiene 216 F (1,63 mol) and Me'kon xylene 70117 were charged, the reactor was sealed, and the mixture was stirred. While stirring, the temperature was raised to 200° C., and stirring was continued for 2 hours while lowering this temperature. After the completion of the reaction, the reactor was cooled with water, a white slurry-like reaction solution was recovered, and after removing unreacted synchropentadiene and xylene, the desired product was distilled under reduced pressure (full point: 113°C/2). .5
mFig). Yield: f185.3 F (yield: 440% based on raw material dicyclopentadiene).

According to NMR analysis, the ratio of Trimer I to ■ was 86:14.

160 y of the cyclopentadiene trimer obtained above was placed in a fAsoo* stainless steel autoclave.
(o,s O7 mmol), dicobalt octacarbonyl 2.89 (8.2 mmol), 9-eicosyl-9
-Phosphabicyclo(3,3,1)nonane and 1 of 9-diicosyl-9-phosphabicyclo(4,2゜1]nonane
= 1 mixture 6.99 (16,3 mmol), and l
Kongo xylene 70*j was charged. After sealing the reactor,
- After purging the inside of the vessel several times with an equimolar mixed gas of carbon oxide and hydrogen, the mixed gas was pressurized to 80 bav at room temperature. The temperature of this reactor was raised to 200° C. while stirring. Rapid gas absorption occurred during temperature rise (around 180°C), and when the reactor was maintained at 200°C while supplying mixed gas so that the pressure was 120 bayy, almost no theoretical gas absorption occurred after 19 hours. finished. After cooling the reactor with water, unreacted gas was purged, and the contents were diluted with methanol and collected. After xylene and methanol were distilled off, the target product was collected by distillation under reduced pressure (Na point 186-204℃ 10.7-0.3
wa I(g). Yield 124.59 (yield 59% based on the raw material cyclopentadiene trimer).

Example 1 Methacrylic acid and acrylic acid were added to 365 parts of PCPD-DM1M7C obtained in the above synthesis example in a 1-liter four-bottle flask equipped with a stirrer, a thermometer, a nitrogen inlet tube, and a water separator. 2.4 mol of a mixture (molar ratio of methacrylic acid and acrylic acid is 1.5; hereinafter M/A ratio = 1
．． 5) 193 parts of toluene, 50 parts of p-toluene sulfone, and 0.3 parts of copper powder were charged at the same time, and the reaction temperature was increased to 90-1 while overflowing nitrogen gas.
The reaction was carried out at 20°C for 3 hours. After the reaction is completed, it is cooled, the excess acid is neutralized with carbonated soda water, and the organic layer is further diluted with pure water.
Washed twice, toluene was distilled off using an evaporator,
380 parts of the desired polymerizable composition having an M/A ratio of 1.5 was obtained.

Add 0.5 parts of penzoyl peroxide to 100 parts of the above polymer composition, heat to 60°C, and stir uniformly (T
1. After combining, defoaming, the liquid was poured into a tube made of a glass tube with a diameter of 120 km and a silicone rubber spacer, and heated at 60°C for 24 hours and at 80°C for 2 hours for 10 hours.
Polymerization was carried out by holding at 0°C for 2 hours.

The cured product was taken out from the mold to obtain an rltf-t120fl disk substrate.

Comparative Example 1 In 100 parts of 1.4-bis(methacroyloxymethyl)cyclohexane, 0.5 parts of penzoylperoquine was added.
After heating to 60℃, stirring and mixing uniformly, defoaming, sealing with a glass plate with a diameter of 120mm and a silicone rubber spacer, pouring into the grown mold, and stirring at 60℃.
Polymerization was carried out by holding the mixture at 80° C. for 2 hours and at 100° C. for 2 hours. Take out the cured product from the mold and make a diameter of 12
I got a 0m disk board.

1 Shichishinko Example 2 1,4-bis(methacroyloxymethyl) of Comparative Example 1
7 Instead of chlorohexane, 2,2'-bis(4,4'-(
A disk closure plate was obtained in the same manner except that β-methacroyloxy)cyclohexyl]propane was used.

Comparative Example 3 1,4-bis(methacroyloxymethyl) of Comparative Example 1
A disk substrate was obtained in the same manner except that bis(oxymethyl)tricyclo(5,2,1,0)acane dimethacrylate was used instead of cyclohexane.

Evaluation results of various physical properties of the substrates obtained in Examples and Comparative Examples 1 to 3 are shown in A-1.

(μ bottom margin)

Claims (1)

[Claims] In a resin for optical materials consisting of a radical polymer of an ethylenically unsaturated monomer, the ethylenically unsaturated monomer is obtained by esterifying 1 mole of pentacyclopentadecane dimethanol with 2 moles of a mixture of acrylic acid and methacrylic acid. A resin for optical materials, characterized in that the obtained di(meth)acrylate mixture is the main component.