JPH0827370A - Aromatic polycarbonate composition - Google Patents

Abstract

PURPOSE:To obtain a composition having low birefringency and being excellent in transparency, mechanical properties and melt flowability by constituting it substantially from a plurality of specified aromatic polycarbonate and specifying the weight ratio among them. CONSTITUTION:This composition is one substantially consisting of an aromatic polycarbonate (A) comprising repeating units represented by formula I and an aromatic polycarbonate (B) comprising repeating units represented by formula II, wherein the weight ratio, A/B, is 80:20 to 30:70. As desirable examples of polymers (A) and (B), polymers each having a specific viscosity of 0.2-0.4 as measured in a solution prepared by dissolving 0.7g of each polymer in 100ml of methylene chloride are selected.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION This invention relates to aromatic polycarbonate compositions. More specifically, it relates to a composition having improved birefringence and moldability, which is formed from two kinds of aromatic polycarbonates, and a molded article made from the composition.

[0002]

2. Description of the Related Art Conventionally, a polycarbonate resin obtained by reacting a carbonate precursor substance with 2,2-bis (4-hydroxyphenyl) propane has excellent transparency, heat resistance, mechanical properties and dimensional stability. Therefore, it is widely used in many fields as engineering plastics. In particular, it has many uses as an optical material because of its excellent transparency.

However, such a polycarbonate resin has a large photoelastic constant due to the optical anisotropy of the benzene ring,
Therefore, there is a defect that the birefringence of the molded product is large, and this improvement is required. There is also a demand for a resin having a better melt flowability and a good transfer property and a short molding cycle.

On the other hand, Japanese Patent Laid-Open No. 2-88634 discloses that
1,1-bis (4-hydroxyphenyl) -3,3,5-
An aromatic polycarbonate resin obtained from trimethylcyclohexane is disclosed, and it is also known that this polymer has low birefringence and good heat resistance, but melt flowability is poor and it is difficult to obtain a good molded product. .

[0005]

SUMMARY OF THE INVENTION An object of the present invention is to improve the oblique incidence birefringence, moldability, warpage, etc. of an aromatic polycarbonate while maintaining the excellent transparency and mechanical properties of the polycarbonate suitable for optical materials. To provide a composition. The present inventor has conducted intensive studies to achieve this object and, as a result, found that a composition obtained by mixing two kinds of specific aromatic polycarbonates in a specific ratio was suitable as an optical material, and arrived at the present invention. .

[0006]

That is, according to the present invention, the following general formula [I]

[0007]

Embedded image

An aromatic polycarbonate (PC-I) comprising a repeating unit [I] represented by the following general formula [I]
I]

[0009]

[Chemical 4]

It substantially consists of an aromatic polycarbonate (PC-II) consisting of the repeating unit [II] represented by the following formula, and the ratio of the aromatic polycarbonate (PC-I) and the aromatic polycarbonate (PC-II) is There is provided an aromatic polycarbonate composition having a weight ratio in the range of 80:20 to 30:70.

4,4 '-(m-Phenylenediisopropylidene) diphenol and 1,1-bis (4-) used in the production of PC-I and PC-II forming the aromatic polycarbonate resin composition of the present invention. Hydroxyphenyl)
-3,3,5-Trimethylcyclohexane preferably has a high purity of 99.0% or more in which impurities by-produced during the synthesis are removed as much as possible. PC-I forming compositions of the present invention
Is 80 to 30% by weight, and PC-II is 20 to 70% by weight. PC-I is 75-35% by weight, PC-II
Is preferably 25 to 65% by weight. 80% by weight of PC-I
If the amount of PC-II is more than 20% by weight, the photoelastic constant of the obtained resin becomes large and the glass transition point becomes low, which is not preferable. If PC-I is less than 30% by weight and PC-II is more than 70% by weight, the melt flowability of the obtained resin is poor and molding failure occurs, making it difficult to obtain an optically good molded product.

Each of the resins forming the aromatic polycarbonate resin composition of the present invention is a known method used for producing an ordinary aromatic polycarbonate resin, for example, dihydric phenol is mixed with a carbonate precursor such as phosgene or carbonic acid diester. It is produced by a reaction method.

In a reaction using, for example, phosgene as a carbonate precursor, the above dihydric phenol is usually dissolved in an aqueous solution of an acid binder and the reaction is carried out in the presence of an organic solvent. An alkali metal hydroxide such as sodium hydroxide or potassium hydroxide is used as the acid binder, and a halogenated hydrocarbon such as methylene chloride or chlorobenzene is used as the organic solvent. Reaction temperature is usually 0-4
It is 0 ° C., and the reaction time is several minutes to 5 hours.

A catalyst may be used to accelerate the reaction, and examples of the catalyst include triethylamine, tetra-n-butylammonium bromide and tetra-n-.
Examples include tertiary amines such as butylphosphonium bromide, quaternary ammonium compounds, and quaternary phosphonium compounds. Further, if necessary, an antioxidant such as hydrosulfite can be added.

Further, as the terminal terminator, for example, monofunctional phenols such as phenol, p-tert-butylphenol, p-cumylphenol and isooctylphenol are used. Further, in order to further improve the melt fluidity, it is advisable to use an alkylphenol having 10 to 50 carbon atoms in an amount of at least 5 mol% of the total end-stopping agent. The substitution position of the alkyl group of the alkylphenol having 10 to 50 carbon atoms used at that time is usually the ortho position or para position of the hydroxyl group, and among them, the mixture of the ortho position and the para position is preferably used.

The transesterification reaction using a carbonic acid diester as a carbonate precursor is carried out by distilling alcohol or phenol produced by stirring the dihydric phenol in a predetermined ratio with the carbonic acid diester in an inert gas atmosphere while heating. Be seen. The reaction temperature varies depending on the boiling point of the alcohol or phenol produced, etc., but is usually in the range of 120 to 300 ° C. In the latter stage of the reaction, the system is depressurized to facilitate the distillation of the produced alcohol or phenol to complete the reaction. Examples of the carbonic acid diester include diphenyl carbonate, dinaphthyl carbonate, bis (diphenyl) carbonate, dimethyl carbonate, diethyl carbonate, dibutyl carbonate and the like. Of these, diphenyl carbonate is particularly preferable.

A polymerization catalyst can also be used to accelerate the polymerization rate. As the polymerization catalyst, hydroxides of alkali metals and alkaline earth metals such as sodium hydroxide and potassium hydroxide, and hydroxides of boron and aluminum can be used. Alkaline metal salts, alkaline earth metal salts, quaternary ammonium salts, alkali metal and alkaline earth metal alkoxides, alkali metal and alkaline earth metal organic acid salts,
Ordinary esterification reaction, transesterification reaction of zinc compounds, boron compounds, silicon compounds, germanium compounds, organotin compounds, lead compounds, antimony compounds, manganese compounds, titanium compounds, zirconium compounds, etc. The catalyst used for can be used. The catalyst may be used alone or in combination of two or more kinds. The amount of these catalysts used is 0.0001 to 1% by weight, preferably 0.000, based on the starting dihydric phenol.
It is selected in the range of 05 to 0.5% by weight.

PC-I and PC-I thus obtained
Polymer I is 0.7 ml of polymer in 100 ml.
Of methylene chloride, the specific viscosity of which is measured at 20 ° C. is preferably in the range of 0.2 to 0.4, and 0.25 to 0.3.
The range of 5 is more preferable. If the specific viscosity is less than 0.2, the molded product becomes brittle, while if it is higher than 0.4, the melt flowability is poor and molding defects occur, making it difficult to obtain an optically good molded product.

The aromatic polycarbonate resin composition of the present invention can be molded by any method such as an injection molding method, a compression molding method, an extrusion molding method and a solution casting method.

The aromatic polycarbonate resin composition of the present invention may optionally contain a phosphorus-based heat stabilizer, a phenol-based antioxidant and the like. Examples of phosphorus-based stabilizers include triphenylphosphite, trisnonylphenylphosphite, and tris (2,4-di-).
(tert-butylphenyl) phosphite, tridecyl phosphite, trioctyl phosphite, trioctadecyl phosphite, didecyl monophenyl phosphite, dioctyl monophenyl phosphite, diisopropyl monophenyl phosphite, monobutyl diphenyl phosphite, monodecyl Diphenylphosphite, monooctyldiphenylphosphite, bis (2,6-di-tert-butyl-4-methylphenyl) pentaerythritol diphosphite, 2,2-methylenebis (4,
6-di-tert-butylphenyl) octylphosphite, bis (nonylphenyl) pentaerythritol diphosphite, bis (2,4-di-tert-butylphenyl) pentaerythritol diphosphite, tetrakis (2,4-diphenyl) -Tert-butylphenyl) -4,4
-Triesters, diesters, and monoesters of phosphorous acid such as diphenylenephosphonite, which may be used alone or in combination of two or more kinds. The amount added is preferably 0.0001 to 0.05% by weight.

Examples of phenolic antioxidants include triethylene glycol-bis (3- (3-tert-butyl-5-methyl-4-hydroxyphenyl) propionate) and 1,6-hexanediol-bis (3- ( Three,
5-di-tert-butyl-4-hydroxyphenyl)
Propionate, pentaerythritol-tetrakis (3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate), octadecyl-3-
(3,5-di-tert-butyl-4-hydroxyphenyl) propionate, 1,3,5-trimethyl-2,4,
6-tris (3,5-di-tert-butyl-4-hydroxybenzyl) benzene, N, N-hexamethylenebis (3,5-di-tert-butyl-4-hydroxy-)
Hydrocinnamide), 3,5-di-tert-butyl-4-hydroxy-benzylphosphonate-diethyl ester, tris (3,5-di-tert-butyl-4-)
Hydroxybenzyl) isocyanurate, 3,9-bis {1,1-dimethyl-2- [β- (3-tert-butyl-4-hydroxy-5-methylphenyl) propionyloxy] ethyl} -2,4,8 Examples include 10,10-tetraoxaspiro (5,5) undecane and the like. The preferred range of addition is 0.0001 to 0.05%.

If desired, higher fatty acid esters of polyhydric alcohols may be added. The preferred fatty acid ester is a total ester or a partial ester of a saturated aliphatic monocarboxylic acid having 8 to 22 carbon atoms and glycols, glycerol, pentaerythritol, etc., and the preferable addition amount is 0.001 to 0.5% by weight. is there. Also a light stabilizer,
Additives such as colorants, antistatic agents and lubricants can be added within a range that does not impair transparency. Other polycarbonate resins or thermoplastic resins may be blended in a small proportion and used.

The chlorine (Cl) contained in the aromatic polycarbonate resin of the present invention is preferably 1.0 ppm or less. In addition, 10000 foreign matter with an average diameter of 0.5 μm or more
It is preferably g or less.

Since the aromatic polycarbonate composition of the present invention is particularly excellent in birefringence and moldability, it can be used as various molded products. Particularly, it is advantageously used as an optical molded product suitable for structural materials or functional material applications of optical components such as optical discs, optical lenses, liquid crystal panels, optical cards, sheets, films, optical fibers, connectors, vapor-deposited plastic reflectors, and displays. can do. Of these, it can be used particularly advantageously as a substrate for optical disks.

[0025]

The present invention will be further described with reference to the following examples. In the synthesis examples and examples, parts are parts by weight and% is% by weight. The evaluation was based on the following method. Specific viscosity: 0.7 g of the polymer was dissolved in 100 ml of methylene chloride and measured at a temperature of 20 ° C. Glass transition point (Tg); measured by DuPont Model 910 DSC. Fluidity (MFR): In accordance with JIS K-7210,
Using a semi-auto melt indexer manufactured by Toyo Seiki, 2
The amount of polymer (g) flowed out at 80 ° C. under a load of 2.16 kg for 10 minutes was shown. Total light transmittance: Measured using Nippon Denshoku Sigma 80 in accordance with ASTM D-1003. Photoelastic constant; photoelasticity measuring device PA manufactured by Riken Keiki Co., Ltd.
It was measured by 150. Oblique incidence birefringence phase difference; oak ellipsometer ADR
The measurement was performed at an incident angle of 30 degrees using a -200B automatic birefringence measuring device. Warp: After leaving the optical disk in a thermo-hygrostat at 80 ° C. and 85% RH for 1000 hours, LM-1200 manufactured by Ono Sokki Co., Ltd.
The warp of the substrate was measured using an optical disc inspection device.

Synthesis Example 1 (Synthesis of PC-I) 1023 parts of ion-exchanged water and 67.5 parts of 48% caustic soda aqueous solution were placed in a reactor equipped with a thermometer, a stirrer and a reflux condenser, and 4,4 '-(m- Phenylene diisopropylidene) diphenol 95.9 parts and hydrosulfite 0.2
70 parts of methylene chloride was added thereto, and 35.7 parts of phosgene was blown thereinto under stirring at 15 to 25 ° C. for 40 minutes to cause a reaction. After the completion of blowing phosgene, pt
After the addition of 1.66 parts of ert-butylphenol and 17.2 parts of a 48% aqueous sodium hydroxide solution to emulsify the mixture, 0.1 part of triethylamine was added and stirred at 28 to 33 ° C. for about 1 hour to complete the reaction. After completion of the reaction, the product was diluted with methylene chloride, washed with water, acidified with hydrochloric acid and washed with water. When the conductivity of the aqueous phase became almost the same as that of ion-exchanged water, methylene chloride was evaporated to obtain 98 parts of a polymer. (Yield 95
%). This polymer has a specific viscosity of 0.275 and a Tg of 98.
° C.

Synthesis Example 2 (Synthesis of PC-II) In the same apparatus as in Synthesis Example 1, 1137.3 parts of ion-exchanged water,
Add 238.5 parts of 48% caustic soda solution, 1,1-
After dissolving 20.1 parts of bis (4-hydroxyphenyl) -3,3,5-trimethylcyclohexane and 0.2 parts of hydrosulfite, 709.9 parts of methylene chloride was added, and the mixture was stirred at 15 to 25 ° C. 83.1 parts of phosgene 4
It took 0 minutes to blow. After finishing blowing phosgene, p
After adding 5.8 parts of -tert-butylphenol and emulsifying,
Triethylamine (0.2 part) was added to obtain 208.2 parts of a polymer in the same manner as in Synthesis Example 1 (yield 96%). The polymer had a specific viscosity of 0.258 and a Tg of 226 ° C.

Synthesis Example 3 (Synthesis of PC-II) Instead of p-tert-butylphenol of Synthesis Example 2, an alkylphenol having 20 carbon atoms (ortho-substituted compound 7)
217.5 parts of polymer was obtained in the same manner as in Synthesis Example 2 except that 14.5 parts of a mixture of 0% and 30% of para-substituted product was used (yield 94%). The specific viscosity of this product is 0.272, T
The g was 182 ° C.

Example 1 70 parts of the polycarbonate synthesized in Synthesis Example 1, Synthesis Example 2
Polycarbonate synthesized in 30 parts, Tris (2,4-
Di-tert-butylphenyl) phosphite 0.00
5 parts, trimethyl phosphate 0.005 parts, steari
Add 0.045 parts of acid monoglyceride to methylene chloride.
After dissolving in one, evaporate the methylene chloride and polymer composition
I got a thing. This is melt extruded at 250 ° C and pelletized.
Turned into This product has a Tg of 132 ° C and an MFR of 80g.
/ 10 minutes. Sumitomo Heavy Industries DISK5M
120mmφ, 1.2mm thick disc
It was injection molded on the substrate. The total light transmittance of this product is 89
%, The photoelastic constant is 41 × 10 ^-13cm²/ Dyn, diagonally inserted
The birefringence phase difference is 20 nm and the warpage is 0.2 mm.
Was.

Example 2 40 parts of the polymer synthesized in Synthesis Example 1 and 60 parts of the polymer synthesized in Synthesis Example 3 were pelletized in the same manner as in Example 1 with the same additive composition as in Example 1. This product has a Tg of 1
At 49 ° C., MFR was 53 g / 10 minutes. When a disk substrate was molded and evaluated in the same manner as in Example 1, the total light transmittance was 89% and the photoelastic constant was 37 × 10.
^-13 cm ² / dyn, oblique incidence birefringence phase difference 23 nm,
The warp was 0.2 mm.

Comparative Example 1 A normal bisphenol A polycarbonate (Panlite AD-5503 manufactured by Teijin Chemicals Ltd.) was molded on the same disk substrate as in Example 1 and evaluated in the same manner as in Example 1. The total light transmittance was 89%. , The photoelastic constant is 82 × 10 ^-13 cm ²
/ Dyn, the oblique incidence birefringence phase difference was 68 nm, and the warpage was 0.3 mm.

Comparative Example 2 A pellet and a disk substrate were obtained in the same manner as in Example 1 except that 90 parts of the polymer synthesized in Synthesis Example 1 and 10 parts of the polymer synthesized in Synthesis Example 2 were used. This product has a Tg of 1
Low as 10 ° C, photoelastic constant 46 × 10 ^-13 cm ² / dy
n, the birefringent phase difference of oblique incidence was as large as 35 nm.

Comparative Example 3 Pelletization was carried out in the same manner as in Example 1 except that 10 parts of the polymer synthesized in Synthesis Example 1 and 90 parts of the polymer synthesized in Synthesis Example 2 were used. This product has a high Tg of 219 ° C and an MFR of
Was not measurable and a good molded product could not be obtained.

[0034]

EFFECT OF THE INVENTION The aromatic polycarbonate composition of the present invention has low birefringence, good melt fluidity, and excellent transparency, and is therefore suitable for various optical molded articles such as optical discs, optical lenses and optical cards. Used.

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Claims (7)

[Claims] 1. The following general formula [I]: And an aromatic polycarbonate (PC-I) comprising a repeating unit [I] represented by the following general formula [II] Which is substantially composed of an aromatic polycarbonate (PC-II) composed of a repeating unit [II] represented by: and the ratio of the aromatic polycarbonate (PC-I) and the aromatic polycarbonate (PC-II) is a weight ratio. 80: 20-3
Aromatic polycarbonate composition in the range of 0:70. 2. The polymers of PC-I and PC-II each have a specific viscosity of a solution of 0.7 g of the polymer dissolved in 100 ml of methylene chloride at 20.degree.
The aromatic polycarbonate composition according to claim 1, which is 2 to 0.4. 3. A phosphorus-based heat stabilizer 0.0001 to 0.05
% By weight and / or phenolic antioxidant 0.00
The aromatic polycarbonate composition according to claim 1, which comprises 01 to 0.05% by weight. 4. The aromatic polycarbonate composition according to claim 1, wherein the polymer of PC-I has an alkylphenyloxy group having 10 to 50 carbon atoms as an end group in an amount of at least 5 mol% or more based on all the ends. 5. The aromatic polycarbonate composition according to claim 1, wherein the PC-II polymer has an alkylphenyloxy group having 10 to 50 carbon atoms as an end group in an amount of at least 5 mol% or more per all ends. 6. An optical material formed from the aromatic polycarbonate composition according to claim 1. 7. A substrate for an optical disc formed from the aromatic polycarbonate composition according to claim 1.