JPH0299561A - Optical aromatic copolymerized polycarbonate resin composition - Google Patents

Abstract

PURPOSE:To obtain the subject composition capable of providing optical disk substrates with high durability without causing defective appearance, such as silver, on the surface of molded products in high-temperature molding by blending an aromatic copolymerized polycarbonate with a specific mold releasable compound and heat stabilizer in specified amounts. CONSTITUTION:A resin composition obtained by blending 100 pts.wt. aromatic copolymerized polycarbonate prepared by linking two or more selected from bisphenols expressed by formulas I to III (R1 and R2 are H, 1-6C alkyl, etc.; R3 is methyl, ethyl, etc.; R4 is 1-6C alkyl) through carbonate bonds with (A) 0.005-0.1 pt.wt. mold releasable compound which is an organic acid ester wax (e.g., montanic acid ester wax) and (B) 0.01-0.1 pt.wt. heat stabilizer which is an organic phosphite-based compound [e.g., a mixture of tris(2,4-di-tert- butylphenyl)phosphite with stearyl 2,6-di-tert-butyl-4-propionate at 2:1 weight ratio].

Description

[Detailed Description of the Invention] (Industrial Field of Application/Prior Art) In recent years, aromatic polycarbonates have been improved in their transparency, mechanical strength,
It is widely used in molded products as an engineering plastic with excellent impact resistance. In particular, it is becoming widely used as a resin for optical disk substrates. As a typical example of precision molding, in order to obtain readable information, a metal or metal oxide that reflects laser light or exhibits a physical change such as phase change or evaporation due to laser light is formed on the optical disk substrate. A thin film is placed in a group to serve as a recording or reading laser light guide.

In order to obtain a durable optical disk, it is important that the groups provided on the aromatic polycarbonate substrate be precisely transferred by the groups cut into the stand bar.

It is well known that a mold release agent is generally mixed in to ensure that the groups are accurately transferred and that the aromatic polycarbonate resin is released from the mold. It is also well known to mix a heat-resistant stabilizer in order to heat the resin to 300°C or higher in order to improve fluidity during disk molding.

Commonly used mold release agents include fluorine compounds, silicon compounds, long chain fatty acid esters, long chain fatty acid amides,
There are metal salts of long-chain fatty acids, and phosphite hindered phenol is well known as a commonly used heat stabilizer. Also, JP-A-47-12
No. 993 discloses the addition of a hydrogen phosphite compound to improve the thermal stability of polycarbonate, but does not disclose anything for optical use.

(Problems to be Solved by the Invention) In the molding of optical disk substrates, etc., which requires molding aromatic polycarbonate at high temperatures, heat stabilizers and mold release agents decompose at high temperatures, resulting in silver or other appearance on the molded surface. These decomposition products not only cause defects, but also reduce the durability of the optical disc.

(Means for solving the problem) Montanic acid ester wax, which does not easily decompose at high temperatures, is used as a mold release agent, and Tris (2,4
-ditert-butylphenyl) phosphite and 2,
0.005 to 0.1 stearyl 6-ditertiary-butylphenyl-4-propionate (mixture in a weight ratio of 2:1) to 100 parts by weight of aromatic polycarbonate, respectively.
The inventors have discovered that by adding 0.001 to 0.1 parts by weight, a highly durable optical disk substrate can be obtained without causing appearance defects such as silver on the molded surface during high temperature molding, leading to the present invention. It is something. That is, the present invention provides: (1) An aromatic copolymerized polycarbonate resin composition for optical use, which is obtained by blending an aromatic copolymerized polycarbonate with a mold release compound and a heat-resistant stabilizer.

(2) Aromatic copolymerized polycarbonate has the following general formula (
The optical aromatic copolymerized polycarbonate resin composition according to (1) above, which is obtained by carbonate bonding two or more selected from the bisphenols represented by I), (II), and (III) as monomers.

(R1 and R2 are hydrogen or a branched alkyl group of 01 to C6, a cyclohexane ring, or an aromatic hydrocarbon group.) (Ra is a methyl group, ethyl group, n-propyl group, 1s
o-propyl group and tert-butyl group. ) is an alkyl group of 01 to C6 including branching.

(3) The optical aromatic copolycarbonate resin composition according to (1) or (2) above, wherein the releasing compound is an organic acid ester wax.

(4) The optical aromatic copolycarbonate resin composition according to (1), (2), or (3) above, wherein the heat-resistant stabilizer is an organic phosphite compound.

(5) The above-mentioned (1) or (
The optical aromatic copolymerized polycarbonate resin composition described in 2), (3), or (4).

Examples of the bisphenol compound giving the structure represented by the general formula (I) described in (2) above include bis-(4-
hydroxyphenyl)methane, 1,1-(4-hydroxyphenyl)ethane, 1,1-bis-(4-hydroxyphenyl)propane, 2,2-bis-(4-hydroxyphenylsynpropane (bisphenol A), 2 ,2-
Bis-(4-hydroxyphenyl)butane, 2,2-bis-(4-hydroxyphenyl)pentane, 2,2-bis-(4-hydroxyphenyl)-3,methylbutane,
2,2-bis-(4-hydroxyphenyl)hexane,
2,2-bis-(4-hydroxyphenyl)-4-methylpentane, 4,41-dihydroxy-2,2,2-triphenylethane, 1,1-bis-(4-hydroxyphenyl)cyclohexane, 2, Examples include 2-bis-(4-hydroxy, 3-chlorophenyl)propane.

In addition, as a bisphenol compound giving the structure represented by formula (II), for example, 2,2-bis-(4-
Hydroxy-3-methylphenyl)propane, 2,2-
Bis-(4-hydroxy-3-ethylphenyl)propane, 2,2-bis-(4-hydroxy-3-isopropylphenyl)propane, 2,2-bis-(4-hydroxy-3-sec, butylphenyl) Propane, 2,2-
Bis-(4-hydroxy-3-tert-butylphenyl)propane and the like can be mentioned.

In addition, as a bisphenol compound giving the structure represented by formula (III), for example, 1,1'-bis-(
4-hydroxyphenyl)-para-diisopropylbenzene, 1,1'-bis-(4-hydroxyphenyl)-
Meta-diisopropylbenzene is mentioned. The copolymer of the present invention preferably has a viscosity average molecular weight in terms of bisphenol A-polycarbonate of 13,000 to 30,000. If it is less than 13,000, the copolymerization becomes brittle, and the
If it exceeds 0.000, melt fluidity will be poor and moldability will be poor. The method for producing the polycarbonate copolymer of the present invention includes: - transesterifying two or three monomers selected from formulas (I), (II), and (III) with diphenyl carbonate and synthesizing them by melt polycondensation; A method of interfacial polymerization or solution polymerization using phosgene is proposed.

Phosphite esters of heat-resistant stabilizers used include, for example, tributyl phosphite and tris(2-ethylhexyl).
, phosphite, tridecyl phosphite, tristearylphosphite, triphenyl phosphite, tricresyl phosphite, tris (nonylphenyl) phosphite, tris (2,4-di-t-butylphenyl) phosphite, decyl -diphenyl phosphite, phenyl di2. Ethylhexylphosphite, phenyl-
Didecyl phosphite, tricyclohexyl phosphite, distearyl-pentaerythrityl-diphosphite, diphenyl, pentaerythrityl-diphosphite, tris (mixed mono-, diphenyl) phosphite, etc., among which triphenyl phosphite,
Tris (nonylphenyl) phosphite, tris (mixed mono-, diphenyl) phosphite, tris (2,4-
Di-t-butylphenyl) phosphite is preferred, and more preferably tris(2,4-ditertiary-butylphenyl) phosphite and stearyl 2,6-ditertiary-butyl-4-propionate in a weight ratio of 2:1. A heat stabilizer mixed with

On the other hand, the mold release compounds used are carnauba wax,
Hoechst wax, montanic acid ester wax, silicone oil, stearic acid, palmitic acid, stearic acid ester, glycerin tristearate, calcium stearate, zinc stearate, etc.
Among these, montan acid ester wax is preferred.

The present invention is not limited to the examples. still,
The viscosity average molecular weight shown in the examples below refers to the intrinsic viscosity [11] and the molecular weight M
[f11= 1.11 X obtained as the relational expression of v
10-'(Mv)0-82 [I, Mummy, And,
Oh, Bayer; U.S. Pat. No. 2,999,844 (191
Bisphenol A calculated from intrinsic viscosity using June's formula
- Molecular weight in terms of polycarbonate.

(Example) Example 1 174 parts by weight (50 mo 1%) of 4,4'-dihydroxy-2,2,2-triphenylethane and 2,2-bis-(
154 parts by weight (50 mo1%) of 4-hydroxy-3-tert-butylphenyl propane and 264 parts by weight of diphenyl carbonate were placed in a 31-lough flask, and after repeating degassing and N2 purge 5 times, they were placed in a silicon bath 16
It was melted at 0°C while nitrogen was being introduced. Once melted,
A solution of potassium borohydride, which is a carbonation catalyst, dissolved in phenol (10-3 mo1% amount based on the total amount of bisphenol charged) was added, and the mixture was heated at 160'C.
N2 lower.

The mixture was stirred and brewed for 30 minutes. Next, under the same temperature IQQTorr
After stirring for 30 minutes, add another 1QQTo at the same temperature.
(After stirring for 30 minutes, add 5Q at the same temperature.
The pressure was reduced to Torr and the reaction was carried out for 30 minutes. Next, the temperature was gradually raised to 220° C. and the reaction was continued for 60 minutes, and 80% of the theoretical amount of phenol was distilled out through the reaction up to this point. Thereafter, the pressure was reduced to 1 Q Torr at the same temperature, and the reaction was carried out for 30 minutes.The temperature was gradually raised to 270°C, and the reaction was carried out for 30 minutes. Further, at the same temperature, the pressure was reduced to 5 Torr and the reaction was allowed to proceed for 30 minutes, and almost all of the theoretical amount of phenol was distilled out to complete the precondensation. Next, condensation was carried out at the same temperature for 2 hours at Q, l-Q, and 3 Torr. After the product polymer was taken out and cooled under nitrogen, the solution viscosity was measured at 20°C using dichloromethane as a solvent. The viscosity average molecular weight Mv calculated from this value was 21,500. Montanic acid ester wax (manufactured by Hoechst) 0.0 as a mold release compound per 100 parts by weight of the copolymerized polycarbonate obtained here.
5 parts by weight, tris(2,4-ditertiarybutylphenyl) phosphite (Mark 2112, manufactured by Adeka Argus), and 2,6-ditertiarybutyl-4-propionate, thearyl (MarkAD-50, manufactured by Adeka Argus). 0.05 parts by weight of a heat-resistant stabilizer made by mixing 2:1 weight ratio of
It was made into a 'C'''C' kneaded pellet.

Example 2 1.1'-bis-(4-hydroxyphenyl)-meta-
116 parts by weight (40ml 1%) of diisopropylbenzene and 1,1'-bis-(4-hydroxyphenyl)-
125 parts by weight (30 m1%) of diisopropylbenzene, 104 parts by weight (30 m1%) of 4,4'-dihydroxy-2,2,2-triphenylethane, and 264 parts by weight of diphenyl carbonate were synthesized in the same manner as in Example 1. .

The viscosity average molecular weight was Mv=20,300. This was mixed with the same amount of the same release compound and heat-resistant stabilizer as in Example 1 to form a pellet.

Comparative Examples 1 and 2 For comparison, copolymerized polycarbonates synthesized in Examples 1 and 2 without a mold release compound and a heat-resistant stabilizer are shown as comparative examples corresponding to the respective examples.

A recording film was attached to the polycarbonate copolymer produced as described above, and the optical recording properties were evaluated.

That is, the polycarbonate copolymers described in Examples 1 and 2 were molded into a disc-shaped substrate with a diameter of 130 mm and a thickness of 1.2 mm using an injection molding machine (Kamaki Seisakusho, Dynamelter), and on this substrate. Tb23.5 Fe64.2CO1
Magneto-optical recording films were formed by 1,000 people in a sputtering device (RF sputtering device, manufactured by Nihon Shinku Co., Ltd.) using an alloy target of 2.3 (atomic %). On this recording film, inorganic glass protective films i and ooo described in Japanese Patent Application Laid-open No. 177449/1983 by the present applicant were formed using the same sputtering apparatus as above. The results are shown in Table 1.

(Note 1) CN ratio = writing power 7mW (milliwatt)
, measured at read power 1mW, carrier frequency IMHz, and 30KHz in resolution band (Note 2) ON change rate (%) = 60° with respect to initial CN ratio
C, degree of decrease in CN ratio after 30 days under 90RH% conditions (effect of the invention) As seen from Table 1, optical aromatic copolymerized polycarbonate resin blended with a specific mold release compound and a heat resistant stabilizer. A highly durable optical disk substrate can be obtained from the composition.

Claims (5)

[Claims] (1) An aromatic copolymerized polycarbonate resin composition for optical use, which is prepared by blending an aromatic copolymerized polycarbonate with a mold release compound and a heat-resistant stabilizer. (2) Aromatic copolymerized polycarbonate has the following general formula (
The optical aromatic copolymerized polycarbonate resin composition according to claim 1, which is obtained by carbonate bonding of two or more bisphenols selected from bisphenols represented by I), (II), and (III) as monomers. ▲There are mathematical formulas, chemical formulas, tables, etc.▼(I) (R_1, R_2 are C_1 to C_ containing hydrogen or branching
6, a cyclohexane ring, or an aromatic hydrocarbon group. ) ▲There are mathematical formulas, chemical formulas, tables, etc.▼(II) (R_3 is a methyl group, ethyl group, n-propyl group, is
They are o-propyl group and tert-butyl group. ) ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ (III) R_4 is an alkyl group of C_1 to C_6 including branching. (3) The optical aromatic copolymerized polycarbonate resin composition according to claim 1 or 2, wherein the mold release compound is an organic acid ester wax. (4) The optical aromatic copolymerized polycarbonate resin composition according to claim 1 or 2, wherein the heat-resistant stabilizer is an organic phosphite compound. (5) Claim 1 comprising 0.005 to 0.1 parts by weight of a mold release compound and 0.01 to 0.1 parts by weight of a heat stabilizer based on 100 parts by weight of the aromatic copolymerized polycarbonate; or The optical aromatic copolymerized polycarbonate resin composition according to item 2, item 3, or item 4.