JPH0684203A - Substrate for optical disk - Google Patents

Abstract

PURPOSE:To provide the substrate for an optical disk having excellent heat resistance and electrical insulation characteristic. CONSTITUTION:This substrate consists essentially of an epoxy resin obtd. by further epoxylating the resin having the vinyl groups obtd. by bringing a compd. having >=1 pieces of the vinyl groups and one piece of epoxy group in one molecule, at least one kind selected from polymers contg. a polybasic acid anhydride, polybasic acid, acid terminal end polymer and carboxylic acid group and at least one kind selected from compds. having >=1 pieces of active hydrogen into reaction and a hardener for this epoxy resin. As a result, the substrate for the optical disk having the excellent heat resistance and electrical insulation characteristic is obtd.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a substrate for an optical disc recording medium which records and reproduces an optical signal at a high speed and a high density, and more particularly to a substrate for an optical disc excellent in low birefringence and heat resistance.

[0002]

2. Description of the Related Art Optical disks, which are high density recording media, are classified into those for reproduction, those which can be recorded by light, those which can be recorded and written.

These optical disks have (1) large capacity (2) long-term recording / storing of recording data (3) non-contact recording / reproducing (4) other information equipment system It is expected to grow as an indispensable element in the information society of the future.

Acrylic resin (PMMA) and polycarbonate resin (PC) are used as materials for these optical disk substrates.
Is currently used.

Generally, the performance required as a material for an optical disk substrate is (1) excellent light transmittance (2) low birefringence (3) low moisture permeability (4) Good heat resistance (5) Excellent moldability, productivity, mechanical strength, surface hardness, etc.

Among the above materials, acrylic resin has hygroscopicity, so warping occurs and heat resistance is lacking.
Polycarbonate resins have excellent hygroscopicity and heat resistance, but have a large birefringence due to the molecular structure, poor flowability, and poor moldability.

Epoxy resin is a highly reliable material in which these drawbacks have been improved.

Epoxy resins for optical disks include glycidyl ether type resins obtained by reacting polychloroalcohol such as bisphenol A, bisphenol F, novolac resin, hydrogenated bisphenol F and epichlorohydrin, And alicyclic epoxy resins.

[0009]

However, a cured product of glycidyl ether of novolak resin has high heat resistance but poor hue, while a cured product of other glycidyl ether type epoxy resin is sufficient. Heat resistance was not obtained. Further, since the main skeleton is a benzene ring, birefringence is not satisfactory.

On the other hand, the alicyclic epoxy resin essentially does not contain chlorine and is superior in heat resistance, transparency and electric characteristics to the glycidyl ether type epoxy resin, but the heat resistance is not sufficient. The present invention provides a substrate for an optical disc which is excellent in heat resistance, transparency, electric characteristics and birefringence.

Further, it has been clarified that the characteristics of the epoxy resin can be changed by giving various combinations of (a), (b) and (c) to be used, and a wide range of characteristics can be given.

[0012]

The present invention comprises (a) a compound having at least one vinyl group and one epoxy group in one molecule, (b) a polybasic acid anhydride, a polybasic acid, Vinyl obtained by reacting at least one selected from acid-terminated polymers and polymers containing carboxylic acid groups with at least one selected from (c) compounds having one or more active hydrogens. The present invention relates to a substrate for an optical disk, which comprises an epoxy resin obtained by further epoxidizing a resin having a group and a curing agent for the epoxy resin as main components.

Next, the present invention will be described in more detail.

The compound having one epoxy group and one or more vinyl groups in one molecule used in the present invention is (IV) << i is an integer of 1 to 5, R ¹ and R ⁴ are hydrogen atoms or alkyl groups having 1 to 50 carbon atoms or substituted phenyl groups,
R ² and R ³ are each a hydrogen atom or an alkyl group having 1 to 50 carbon atoms, and R ² and R ³ may be wrapped around a ring.

Examples of the compound represented by (IV) are the compounds shown below.

4-vinylcyclohexene-1-oxide, 5-vinylbicyclo [2.2.1] hept-2-ene-2-oxide, limonene monoxide, trivinylcyclohexane monoxide, divinylbenzene monoxide, butadiene mono Oxide and 1,2-epoxy-
Examples include compounds represented by (I) such as 9-decene, compounds represented by (II) such as allyl glycidyl ether, and compounds such as glycidyl styryl ether.

Further, the following compounds can also be used.

[0018]

[Chemical 1]

[Chemical 2]

[Chemical 3]

[Chemical 4] These may be used alone or in combination of two or more.

If necessary, ethylene oxide,
Propylene oxide, cyclohexene oxide, styrene oxide, monoepoxides such as α-olefin epoxide, vinyl cyclohexene dioxide, 3,4-
A diepoxide such as epoxycyclohexylmethyl-3,4-epoxycyclohexylcarboxylate may be used at the same time as the compound having one epoxy group and one or more vinyl groups in one molecule.

The polybasic acid anhydrides or polybasic acids (b) used in the present invention include aromatic polybasic acids and acid anhydrides thereof, and aliphatic polybasic acids and acid anhydrides thereof. Examples of aromatic polybasic acids and acid anhydrides thereof include:
Examples include phthalic anhydride, isophthalic acid, terephthalic acid and trimellitic anhydride. Examples of the aliphatic polybasic acid and its acid anhydride include tetrahydrophthalic acid, 4-methylhexahydrophthalic acid, hexahydrophthalic acid, adipic acid, maleic acid, and their acid anhydrides, fumaric acid and sebacic acid. , Dodecane diacid, and their acid anhydrides.

The acid-terminated polymer used in the present invention is an acid-terminated polymer obtained by reacting a polybasic acid with polyethylene glycol, polypropylene glycol, polytetramethylene glycol, polybutylene glycol, polycyclohexene glycol, polyvinyl cyclohexene glycol or the like. Examples include ethers, acid-terminated polyesters, acid-terminated polybutadienes and acid-terminated polycaprolactones.

Further, an acrylic copolymer having a carboxylic acid group can be used instead of the acid terminal polymer, and it contains a polybasic acid anhydride, a polybasic acid, an acid terminal polymer, and a carboxylic acid group. These polymers may be used alone or in combination of two or more.

Next, as the compound (c) having active hydrogen used in the present invention, alcohols, phenols, carboxylic acids, amines, thiols, hydroxyl-terminated polymers, and hydroxyl groups can be used. The polymer etc. which are contained are mentioned. The alcohols are monovalent, divalent, trivalent or higher, and include, for example, methanol, ethanol, benzyl alcohol, ethylene glycol, propylene glycol, diethylene glycol, dipropylene glycol, butanediol, Examples include hexanediol, glycerin, butanetriol, trimethylolethane, trimethylolpropane, pentaerythritol, diglycerol, triglycerol and the like. In addition, neopentyl glycol, neopentyl glycol ester of hydroxyhivalic acid, dipentaerythritol, 1,4-cyclohexanedimethanol, trimethylpentanediol,
1,3,5-Tris (2-hydroxyethyl) cyanuric acid, hydrogenated bisphenol A, hydrogenated bisphenol A ethylene oxide adduct, bisphenol A propylene oxide adduct and the like can also be used.

Examples of the phenols include phenol, cresol, catechol, pyrogallol, hydroquinone,
Hydroquinone monomethyl ether, bisphenol A, bisphenol F, 4,4'-dihydroxybenzophenone, bisphenol S, ethylene oxide adduct of bisphenol A, propione oxide adduct of bisphenol A, phenol Resin and cresol-novolak resin.

Examples of the hydroxyl group-terminated polymer used in the present invention include polyether polyols such as polyethylene glycol, polypropylene glycol, polytetramethylene glycol, polybutylene glycol, polycyclohexene glycol and polyvinyl cyclohexene glycol, hydroxyl group terminated polyesters, hydroxyl group terminated polybutadiene, Examples include hydroxyl-terminated polycaprolactone and polycarbonate diol. Further, an acrylic copolymer having a hydroxyl group or the like can be used instead of the hydroxyl group-terminated polymer.

As carboxylic acids, formic acid, acetic acid, propionic acid, butyric acid, fatty acids of animal and vegetable oils, fumaric acid, maleic acid, adipic acid, dodecane diacid, trimellitic acid, pyromellitic acid, polyacrylic acid, phthalic acid, isophthalic acid. Acid, terephthalic acid, etc.

Further, compounds having both a hydroxyl group and a carboxylic acid, such as lactic acid, citric acid and oxycaproic acid, can also be mentioned.

The amines include monomethylamine, dimethylamine, monoethylamine, diethylamine, propylamine, monobutylamine, dibutylamine, pentylamine, hexylamine, cyclohexylamine,
Octylamine, dodecylamine, 4,4'-diaminodiphenylmethane, isophoronediamine, toluenediamine, hexamethylenediamine, xylenediamine, diethylenetriamine, triethylenetetramine, ethanolamine and the like.

As the thiols, methyl mercaptan,
Mercapto such as ethyl mercaptan, propyl mercaptan, phenyl mercaptan, mercaptopropionic acid or polyhydric alcohol ester of mercaptopropionic acid, for example, ethylene glycol dimercaptopropionic acid ester, trimethylolpropane trimercaptopropionic acid, pentaerythritol pentamercaptopropionic acid, etc. Can be given.

Further, as the compound having active hydrogen, polyvinyl alcohol, polyvinyl acetate partial hydrolyzate, starch, cellulose, cellulose acetate, cellulose acetate butyrate, hydroxyethyl cellulose, acrylic polyol resin, styrene allyl alcohol copolymer resin, Styrene-maleic acid copolymer resin, alkyd resin, polyester polyol resin,
Examples include polyester carboxylic acid resins, polycaprolactone polyol resins, polypropylene polyols, polytetramethylene glycol, and the like.

The compound having active hydrogen may have an unsaturated double bond in its skeleton, and specific examples thereof include allyl alcohol, acrylic acid, methacrylic acid,
There are 2-hydroxyethyl methacrylate, 3-cyclohexenemethanol, tetrahydrophthalic acid and the like.

Any compound having these active hydrogens can be used, and two or more kinds thereof may be mixed.

The epoxy resin used in the present invention is a compound (a) having at least one vinyl group and one epoxy group in the above molecule, a polybasic acid anhydride, a polybasic acid, and an acid terminal polymer. And a vinyl group-containing resin obtained by reacting at least one selected from the polymer (b) containing a carboxylic acid group and at least one selected from the compound (c) having active hydrogen. Obtained by epoxidation with an epoxidizing agent.

The starting materials (a), (b),
The charging ratio of (c) is 1 to 99 parts by weight of (a), preferably 30 to 80 parts, 99 to 1 part by weight of (b), preferably 20 to 70 parts, and 0 to 99 parts by weight of (c). Parts, preferably 0 to 30 parts.

The component (c) may not be used depending on the case. When the component (c) is not used, it is necessary to control the molecular weight while detecting the dehydration amount by controlling the reaction time, the degree of reduced pressure, the reaction temperature and the like.

When the amount of the component (a) used is relatively small, the epoxy group content in the target epoxy resin is small. The molar ratio of component (a) / component (b) is
It is 0.4 to 5.0, preferably 0.5 to 3.0.

When the proportion of component (a) is high, the proportion of hydroxyl groups at the terminals increases, and when there are hydroxyl groups and carboxyl group terminals, all the terminals become hydroxyl groups as the dehydration reaction proceeds.

On the contrary, when the ratio of the component (b) is high, the ratio of the terminal being a carboxyl group is large, and when the terminal of the hydroxyl group and the terminal of the carboxyl group are present, all the terminals become the carboxyl groups as the dehydration reaction proceeds. . However, (a)
If the ratio of the components is unnecessarily large, part of the component (a) will remain unreacted. Further, when the ratio of the component (b) becomes unnecessarily large, the component (b) remains without reacting.

In the reaction for synthesizing the resin having a vinyl group, a catalyst for promoting the ring-opening reaction of the epoxy group by the carboxyl group and, if necessary, a catalyst for promoting the (dehydration) esterification reaction may be used in combination. Good.

As the catalyst for promoting the ring-opening reaction of an epoxy group with a carboxyl group which can be used in the present invention, a tertiary amine such as dimethylbenzylamine, triethylamine, tetramethylethylenediamine, tri-n-octylamine, or tetramethylammonium chloride is used. , Quaternary ammonium salts such as tetramethylammonium bromide and tetrabutylammonium bromide, alkylureas such as tetramethylurea, and alkylguanidines such as tetramethylguanidine.

The catalyst for promoting the ring-opening reaction that can be used in the present invention may be used alone or in combination of two or more kinds. This catalyst is 0.1 to 5.0 relative to the epoxy compound.
%, Preferably 0.5 to 3.0% by weight. The ring-opening reaction is 50 to 200 ° C, preferably
It is carried out at 100 to 180 ° C.

Examples of the catalyst for promoting the (dehydration) esterification reaction that can be used in the present invention include Sn compounds such as tin octylate and dibutyltin laurate, and Ti compounds such as tetrabutyl titanate.

The catalyst for promoting the (dehydration) esterification reaction used in the present invention may be used alone or in combination of two or more kinds. This catalyst is 0-100 with respect to the reaction system.
It is recommended to use 0 ppm, preferably 50 to 500 ppm.

This (dehydration) esterification reaction is 180 to 2
Perform at 40 ° C.

Although the ring-opening reaction of the epoxy group with the carboxyl group and the (dehydration) esterification reaction may be carried out in sequence, the reaction temperature is raised stepwise in accordance with the progress of the reaction after the raw materials and the catalyst have been charged all at once. Method is preferred. If necessary, after the component (c) and the catalyst are charged at once,
The components (a) and (b) may be dropped.

The resin having a cyclic olefin or vinyl group thus synthesized is reacted with an epoxidizing agent to synthesize the resin having an epoxy group of the present invention. As peracids,
Examples thereof include hydroperoxides.

Examples of peracids include formic acid, peracetic acid, perbenzoic acid and trifluoroperacetic acid. Of these, peracetic acid is industrially produced in large quantities and is available at low cost.
It is also a preferred epoxidizing agent because of its high stability.

Hydroperoxides include hydrogen peroxide, tertiary butyl hydroperoxide, cumene peroxide and the like.

In the epoxidation, a catalyst can be used if necessary.

For example, in the case of peracid, an alkali such as sodium carbonate or an acid such as sulfuric acid can be used as a catalyst.

In the case of hydroperoxides,
A mixture of tungstic acid and caustic soda with hydrogen peroxide,
Alternatively, a catalytic effect can be obtained by using an organic acid in combination with hydrogen peroxide or molybdenum hexacarbonyl in combination with tertiary butyl hydroperoxide.

The epoxidation reaction is carried out by adjusting the presence or absence of a solvent and the reaction temperature according to the physical properties of the equipment and raw materials.

The reaction temperature range that can be used depends on the reactivity of the epoxidizing agent used.

Regarding the preferred epoxidizing agent, peracetic acid, 0 to 70 ° C. is preferable.

The reaction is slow below 0 ° C., and the decomposition of peracetic acid occurs at 70 ° C.

In the tertiary butyl hydroperoxide / molybdenum dioxide diacetylacetonate system, which is an example of hydroperoxide, 2 is used for the same reason.
0 degreeC-150 degreeC is preferable.

The solvent can be used for the purpose of reducing the viscosity of the raw material and stabilizing it by diluting the epoxidizing agent.
In the case of peracetic acid, aromatic compounds, ethers, esters and the like can be used.

The charged molar ratio of the epoxidizing agent to the unsaturated bond can be changed according to the purpose such as how much unsaturated bond is desired to remain.

When a compound having a large number of epoxy groups is intended, the epoxidizing agent is preferably added in an equimolar amount or more with respect to the unsaturated group.

However, it is usually disadvantageous that the amount exceeds 2 times the molar amount in view of economical efficiency and side reactions. In the case of peracetic acid, the molar amount is preferably 1 to 1.5 times.

The composition of interest can be removed from the crude reaction liquid by chemical engineering means such as concentration.

The epoxy resin used in the present invention can be used as a mixture with other epoxy resins as long as the characteristics of the composition are not impaired. Here, the other epoxy resin may be any as long as it is generally used,
Examples include epibis-type epoxies, bisphenol F epoxies, novolac epoxies, cycloaliphatic epoxies and epoxy diluents such as styrene oxide and butylglycidyl ether.

As the curing agent used in the present invention, known curing agents used for epoxy resins can be used, and amines, polyamide resins, acid anhydrides, polymercaptan resins, novolac resins, dicyandiamide, boron trifluoride can be used. And a cationic catalyst such as an amine complex.

Here, the amines include the following.

Diethylenetriamine, triethylenetetramine, mensendiamine, metaxylylenediamine,
Aliphatic polyamines such as bis (4-amino-3-methylcyclohexyl) methane, adducts of the aliphatic polyamines with known epoxy compounds, reaction products of acrylonitrile, and reaction products of ketones.

Aromatic polyamines such as metaphenylenediamine, diaminodiphenylmethane, diaminodiphenylsulfone and diaminodiphenyl sulfide, and adducts of said aromatic polyamines with known epoxy compounds,
Secondary and tertiary amines and salts thereof such as tris (dimethylaminomethyl) phenol, piperidine, imidazole and its derivatives, and mixtures of said amines.

The polyamide resin includes a reaction product of a fatty acid such as a fatty acid, a dimer acid and a trimer acid with an aliphatic polyamine.

The acid anhydride includes the following.

Phthalic anhydride, trimellitic anhydride, pyromellitic anhydride, benzophenone tetracarboxylic dianhydride, tetrahydrophthalic anhydride, hexahydrophthalic anhydride, methyltetrahydrophthalic anhydride, methylhexahydrophthalic anhydride, methylanhydride Acid anhydrides such as nadic acid, succinic anhydride, dodecenyl succinic anhydride, and mixtures of said acid anhydrides.

Novolak resins include low molecular weight resinous products made by condensation of phenol or a mixture of phenol and cresol, dihydroxybenzene and formaldehyde.

As the amine complex of boron trifluoride, monoethylamine, piperidine, aniline, butylamine,
A complex of boron trifluoride and a low molecular weight amine compound such as dibutylamine, cyclohexylamine, dicyclohexylamine, tributylamine, and triethanolamine is included.

Other curing agents include salts of super strong acids such as boron tetrafluoride, phosphorus hexafluoride and arsenic hexafluoride, such as diazonium salts, iodonium salts, bromonium salts and sulfonium salts. Among these curing agents, aliphatic polyamine, aromatic polyamine, polyamide resin,
The polymercaptan resin can be mixed and used at an arbitrary ratio, and can be used alone or in combination with a curing accelerator for the purpose of controlling the curing rate. Here, the secondary and tertiary amines can be used as the curing accelerator.

The acid anhydride can be used as it is, but it is also possible to use a curing catalyst and a curing accelerator together for the purpose of adjusting the curing rate and improving the physical properties of the cured product. Here, the curing catalyst is the secondary and tertiary amines and tin octylate. Water as a curing accelerator,
Alcohols such as ethanol, propanol, isopropanol, cyclohexanol and ethylene glycol,
Examples are carboxylic acids such as acetic acid, propionic acid, succinic acid, and hexahydrophthalic acid, and amines having active hydrogen such as ethylenediamine and diethylenetriamine.

The novolac resin may be used alone or in combination with a curing catalyst for the purpose of controlling the curing rate. Here, the curing catalyst is the secondary and tertiary amines. Dicyandiamide can be used alone or in combination with a curing catalyst for the purpose of adjusting the curing rate. here,
As the curing catalyst, the above-mentioned secondary and tertiary amines are used.

The amine complex of boron trifluoride may be used alone or in combination with a curing rate adjusting agent for the purpose of controlling the curing rate. Here, as the curing rate adjusting agent, if it can be used in the conventional epoxy resin,
Although it may be anything, specifically, for example, carboxylic acids, amines, metal acetylacetone complexes, organometallic compounds of metals such as titanium and tin, glycols, organoboron compounds and the like are included.

In addition to the epoxy resin and the curing agent used for the optical disk substrate of the present invention, a release agent, a flame retardant, and
Stabilizers, pigments, dyes and the like may be added.

As a general method for producing the optical disk substrate of the present invention, when a solid sealing agent is used, a raw material composition in which an epoxy resin, a curing agent, etc. are selected at a predetermined composition ratio is used. And the like, followed by melt-mixing treatment using a heat roll, or mixing treatment using a kneader, etc., followed by cooling and solidifying, and pulverizing to an appropriate size to obtain a composition. You can

In the case of a liquid composition, a predetermined amount of an epoxy resin curing agent or the like can be mixed with a mixer or the like to obtain a one-part or two-part composition.

A substrate for an optical disk is molded from the composition thus prepared by a molding method such as a low pressure transfer molding method, an injection molding method, a compression molding method or a casting method.

[0080]

The optical disk substrate of the present invention obtained as described above has good heat resistance, water resistance, and excellent birefringence, and is used not only for reproduction-only optical disks and writable optical recording but also for writing. It can be used as an erasable magneto-optical disk.

The present invention will be described in detail below with reference to examples.

Claims (11)

[Claims] 1. (a) A compound having one or more vinyl groups and one epoxy group in one molecule, and (b) a polybasic acid anhydride, a polybasic acid, an acid terminal polymer, and a carboxylic acid. At least one selected from the group-containing polymers, (c)
A resin having a vinyl group obtained by reacting at least one selected from compounds having one or more active hydrogens, and an epoxy resin obtained by epoxidation and a curing agent for epoxy resin as main components Substrate for optical disk characterized by. 2. The optical disk substrate according to claim 1, wherein the compound having one or more vinyl groups and one epoxy group in one molecule is 4-vinylcyclohexene-1-oxide. 3. The compound having one or more vinyl groups and one epoxy group in one molecule is 5-vinylbicyclo [2.2.1] hept-2-ene-2-oxide. Substrate for optical disk 1. 4. The optical disk substrate according to claim 1, wherein the compound having one or more vinyl groups and one epoxy group in one molecule is limonene monoxide. 5. The substrate for an optical disk according to claim 1, wherein the compound having one or more vinyl groups and one epoxy group in one molecule is a compound represented by the following formula (I). << n is an integer from 0 to 30 >> 6. The substrate for an optical disc according to claim 1, wherein the compound having one or more vinyl groups and one epoxy group in one molecule is a compound represented by the following formula (II). (Chemical formula 2) << n1 and n2 are integers from 0 to 30 >> 7. The substrate for an optical disc according to claim 1, wherein the compound having one or more vinyl groups and one epoxy group in one molecule is a compound represented by the following formula (III). << Ph is a substituted phenyl group, n is an integer from 0 to 30 >> 8. A compound having one or more active hydrogens,
The optical disk substrate according to claim 1, which is an alcohol, a hydroxyl group-terminated polymer, or a polymer containing a hydroxyl group. 9. The optical disk substrate according to claim 1, wherein the acid-terminated polymer is an acid-terminated polyester. 10. The optical disk substrate according to claim 8, wherein the hydroxyl-terminated polymer is a hydroxyl-terminated polyester. 11. The optical disk substrate according to claim 8, wherein the hydroxyl-terminated polymer is a hydroxyl-terminated polyether.