JPS6356556A - Polycarbonate resin composition - Google Patents

Abstract

PURPOSE:To obtain a polycarbonate resin composition having improved mechanical characteristics, low optical strain and low birefringence, by blending a polycarbonate copolymer having specific structure with a styrenic resin. CONSTITUTION:(A) 50-95pts.wt. polycarbonate copolymer which is obtained by reacting a bifunctional phenol (bisphenol A, etc.) shown by formula I (R1 and R2 are H, 1-5C alkyl, 6-10C aryl or 7-12C aralkyl; R3 and R4 are H, halogen or 1-5C alkyl) with a bifunctional phenol (4,4'-biphenol, etc.) shown by formula II (R5 and R6 are H or 1-5C alkyl) and a carbonic acid ester forming compound (phosgene, etc.) and has repeating units shown by formulas III and IV is uniformly blended with (B) 5-50pts.wt. styrenic resin such as styrene-maleic anhydride copolymer, etc., to give the aimed resin composition.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a polycarbonate resin composition having excellent optical properties and comprising a polycarbonate copolymer and a styrene resin.

[Conventional technology]

Traditionally, typical polycarbonate resins are 2.2
-Bis-(4-hydroxyphenyl)propane (commonly known as bisphenol A) is used as a raw material, and one obtained by reacting it with phosgene or diphenyl carbonate is used. Since this material has excellent transparency and mechanical strength, it is used in a wide range of applications as an engineering plastic.

By the way, plastic optical elements have been gaining popularity in recent years because they have advantages such as being lighter than glass ones, having excellent impact resistance, no polishing required, easy mass production, and the ability to mass produce aspherical lenses. The demand for it is increasing.

Polycarbonate is known to be useful as a material for plastic optical elements because it has excellent optical properties such as transparency, heat resistance, mechanical strength, and high refractive index. It is not suitable as an optical material because the stress and strain generated during the molding process is large and birefringence occurs. There has been an attempt to improve the optical properties by blending polystyrene into this polycarbonate (Japanese Unexamined Patent Publication No. 19656/1983), but the two are incompatible, making uniform dispersion difficult, and causing light scattering and optical distortion. It has the problem of being large.

[Problem that the invention seeks to solve]

Under these circumstances, an object of the present invention is to provide a polycarbonate resin composition comprising a polycarbonate copolymer with low optical distortion and useful as a material for optical devices.

[Means for solving problems]

As a result of intensive research into polycarbonate resin compositions, the present inventors discovered that a composition containing a polycarbonate copolymer with a specific structure and a styrene resin has low birefringence and excellent optical properties. ,
Based on this knowledge, we have completed the present invention.

That is, the present invention is based on the general formula (wherein R1 and R2 are each a hydrogen atom and a carbon number of 1 to 5
is an alkyl group having 6 to 10 carbon atoms, or an aralkyl group having 7 to 12 carbon atoms, R3 and R4 are each a hydrogen atom, a halogen atom, and an alkyl group having 1 to 5 carbon atoms, and R5 and R& are Each has a hydrogen atom or 1 carbon number
Provided is a polycarbonate resin composition characterized in that 5 to 50 parts by weight of a styrene resin is blended to 50 to 95 parts by weight of a polycarbonate copolymer having a repeating unit represented by 5 to 5 alkyl groups. It is something.

The polycarbonate copolymer used in the resin composition of the present invention is, for example, a dihydric phenol represented by the general formula (in which R1, R2, R3, R4, R5, R& have the same meanings as above) It can be produced by reacting with a carbonate ester-forming compound.

The general formula (I[[) used as a raw material for this copolymer
Specifically, compounds having the structure represented by are bis(4-hydroxyphenyl)methane, 1,1-bis(
4-hydroxyphenyl)ethane, 2,2-bis(4-
hydroxyphenyl)propane, 2,2-bis(3-methyl-4-hydroxyphenyl)propane, 2,2-bis(4-hydroxyphenyl)butane, 4,4-bis(
4-hydroxyphenyl)pentane, 4,4-bis(4
-hydroxyphenyl)hexane, 4.4-bis(4-
hydroxyphenyl)hebutane, 2゜2-bis(4-hydroxyphenyl)octane, 2.2-(3,5,3
',5'-tetrabromo-4,4'-dihydroxydiphenyl)propane, (3,3'-dichloro-4,4'-
dihydroxydiphenyl)methane, 1,1-bis(4-
hydroxyphenyl)-1-phenylethane, 1.1-
Bis(4-hydroxyphenyl)-1-phenylmethane, 1.1-bis(4-hydroxyphenyl)-1-(4
-ethylphenyl)methane, 1°1-bis(4-hydroxyphenyl)-benzyl-methane, and the like.

Further, specific examples of the compound having the structure represented by the general formula (IV) include 4,4'-biphenol, 2,2
'-biphenol, 3,3'-dimethyl-4,4'-dihydroxydiphenyl, and the like.

On the other hand, examples of carbonate-forming compounds include phosgene, diphenyl carbonate, di-p-tolyl carbonate, phenyl-p-)lyl carbonate, and di-p-tolyl carbonate.
- bisaryl carbonates such as chlorophenyl carbonate and dinaphthyl carbonate.

The method for producing the copolymer includes known methods used in producing polycarbonate from bisphenol A, such as direct reaction of dihydric phenol and phosgene.
Alternatively, a method such as a transesterification reaction between a dihydric phenol and a bisaryl carbonate can be employed.

In the former direct reaction method of dihydric phenol and phosgene, the dihydric phenol represented by the general formulas (Ill) and (■) is reacted with phosgene, usually in the presence of an acid binder and a solvent.

Examples of acid binders used include pyridine and alkali metal hydroxides such as sodium hydroxide and potassium hydroxide. Examples of solvents include methylene chloride,
Chlorobenzene, xylene, etc. are used. moreover,
A catalyst such as a tertiary amine such as triethylamine or a quaternary ammonium salt is used to accelerate the polycondensation reaction, and a molecular weight regulator such as pt-butylphenol or phenylphenol is used to adjust the degree of polymerization. It is desirable to carry out the reaction by adding . Further, a small amount of an antioxidant such as sodium sulfite or hydrosulfide may be added as desired.

The ratio of dihydric phenol (■) and (IV) to be used is arbitrary; if you want to obtain a resin composition with a styrene resin that has low birefringence, use the compound (TV). The proportion is preferably 5 to 30 mol% of the total dihydric phenol.

The reaction is usually carried out at a temperature ranging from 0 to 150°C, preferably from 5 to 40°C. The reaction time depends on the reaction temperature, but is usually 0.5 minutes to 10 hours, preferably 1 minute to 2 hours.
It's time. Further, during the reaction, it is desirable to maintain the pH of the reaction system at 10 or higher.

On the other hand, in the latter transesterification method, the general formula (1
The dihydric phenols represented by [I) and (IV) and bisaryl carbonate are mixed and reacted under reduced pressure at high temperature. The reaction is usually carried out at a temperature in the range of 150 to 350°C, preferably 200 to 300°C, and the final degree of vacuum is preferably 1 wmHg or less to remove the phenols derived from the bisaryl carbonate produced by the transesterification reaction. is distilled out of the system. The reaction time depends on the reaction temperature, degree of pressure reduction, etc., but is usually about 1 to 4 hours. The reaction is preferably carried out under an inert gas atmosphere such as nitrogen or argon, and if desired, the above-mentioned molecular weight regulator, antioxidant, etc. may be added to carry out the reaction.

The polycarbonate copolymer thus obtained is
It has a repeating unit represented by the above general formula, and the reduced viscosity [ηSρ/c] of a solution with a concentration of 0.5 g/dl using methylene chloride as a solvent at a temperature of 20°C is 0.2 dl/g. The above are preferably used. If the reduced viscosity is less than 0.2 dl/g, the mechanical strength will be insufficient.

In addition to polystyrene, the styrene resins to be blended with the above-mentioned polycarbonate copolymer include poly(p-methylstyrene), poly(m-methylstyrene), poly(α-methylstyrene), and poly(t-butyl). styrene)
, poly(alkyl-substituted styrene) such as poly(t-amylstyrene), poly(p-chlorostyrene), poly
Poly (halogen-substituted styrene) such as (m-chlorostyrene), and mixtures thereof, as well as copolymers of styrene compounds and unsaturated monocarboxylic acids or unsaturated dicarboxylic acids or derivatives thereof, such as styrene-anhydride. Maleic acid copolymers and other unsaturated compounds copolymerizable with styrene compounds, such as acrylonitrile,
Methyl methacrylate, methyl acrylate, etc. 1
Examples include those copolymerized with a styrene compound within 0 mol%.

The blending ratio of the above polycarbonate copolymer and styrene resin is 50 to 95 parts by weight of the former and 5 to 5 parts by weight of the latter.
It is necessary to place 0 parts by weight.

If the blending ratio of the styrene resin is less than 5 parts by weight, the effect of improving optical properties will be small, and if it exceeds 50 parts by weight, optical properties, heat resistance, and mechanical strength will decrease.

The polycarbonate copolymer and styrene resin can be uniformly mixed by a known melt-kneading method using an injection molding machine, an extruder, a kneader, a Banbury mixer, etc., or by dissolving them in a common solvent such as methylene chloride. Examples include a method in which the solvent is mixed with a solvent and then dried.

Examples of molding methods for the resin composition of the present invention include methods normally used for molding polycarbonate resins, such as injection molding, compression molding, the low-links method that is a combination of injection molding and compression molding, and micromolding. Any method can be used.

In the above molding method, the composition may be molded as is, but if desired, the composition may be added with various components, such as phosphorous esters and melt index to prevent coloring and deterioration of transparency. It may be molded with a plasticizer added thereto to increase the value, or it may be molded with other resins added as long as the properties of the composition of the present invention are not affected.

Examples of the phosphite esters used in this case include tributyl phosphite, tris(2-ethylhexyl) phosphite, tridecyl phosphite, trisstearyl phosphite, triphenyl phosphite, tricresyl phosphite, and tris(2-ethylhexyl) phosphite. nonylphenyl) phosphite, 2-ethylhexyldiphenyl phosphite, decyl diphenyl phosphite, phenyl-di-2-
Examples include ethylhexyl phosphite, phenyldidecyl phosphite, tricyclohexyl phosphite, distearylpentaerythrityl diphosphite, diphenylpentanyl strityl diphosphite, and the like.

Examples of plasticizers include alkyl phthalates such as 2-ethylhexyl phthalate, n-butyl phthalate, isodecanyl phthalate, tridecanyl phthalate, heptyl phthalate, and nonyl phthalate, 2-ethylhexyl adipate, and 2-ethylhexyl adipate. Alkyl esters of diIM acids such as ethylhexyl sebacate, phosphate alkyl esters such as tributyl phosphate, trioctyl phosphate, tricresyl phosphate, triphenyl phosphate, epoxidized octyl oleate, epoxidized butyl oleate, etc. Examples include epoxidized fatty acid esters, polyester plasticizers, and chlorinated fatty acid esters.

These additives can be blended into the resin by tri-blending, melt-mixing during pelletization using an extruder, creating a master pellet with a high concentration of additives, or tri-blending with pellets without additives. Examples include methods.

The thermoplastic resin composition of the present invention obtained in this manner has excellent transparency, heat resistance, and mechanical strength, and has the characteristics of low optical distortion.

〔Example〕

EXAMPLES Next, the present invention will be explained in more detail with reference to examples, but the present invention is not limited to these examples in any way.

Example 1 (1) Production of polycarbonate copolymer In a flask with an internal volume of 11, 70 g (0,307 mol) of 2,2-bis(4-hydroxyphenyl)propane was dissolved in 480 ml of a 6% aqueous sodium hydroxide solution. Then, 250 ml of methylene chloride was added, and while stirring, phosgene gas was blown in at a rate of 900 ml/min for 14 minutes to form a methylene chloride solution of a polycarbonate oligomer having a chloroformate group terminal with a degree of polymerization of 2 to 3. Obtained.

Next, this solution 30 Qmj! was diluted with methylene chloride to make 450 ml, and after adding 0.8 g of p-tert-butylphenol as a molecular weight regulator, 4.4'
- Add a solution of 7.0 g of biphenol and 8.6 g of 2,2-bis(4-hydroxyphenyl)propane dissolved in 140 rrIt of a 2N sodium hydroxide aqueous solution, and then add 1 ml of a 7% by weight aqueous triethylamine solution as a catalyst. was added, 5 ml of a 12.5N aqueous sodium hydroxide solution was added, and the mixture was allowed to react for 1 hour.

After washing the methylene solution of the copolymer thus obtained, it was poured into methanol to obtain 98 g of a white copolymer. This copolymer was prepared using methylene chloride as a solvent.
I want to measure a solution of 1 degree g/dlt at 20°C.The following examples are similar) Reduced viscosity (77s p/c) is 0.4
It was 2 dl/g. Further, the glass transition temperature (Tg) of this copolymer was 148°C. Further, as a result of NMR spectrum analysis, the content of the repeating unit represented by formula (n) in the copolymer was 11 mol %, indicating that the copolymer was represented by the following formula.

(2) Manufacture and evaluation of composition The weight average molecular weight of the styrene resin was 1160.
000 polystyrene (manufactured by Idemitsu Petrochemical ■; Idemitsu Styrene IFIO) was blended with 35 parts by weight of polystyrene (manufactured by Idemitsu Petrochemical ■; Idemitsu Styrofoam IFIO) and molded using an injection molding machine [manufactured by Sumitomo Heavy Industries; A molded product with a wall thickness of 2.75H was obtained. The light transmittance of the molded article obtained here at a wavelength of 633 nm was measured using a spectrophotometer. Regarding birefringence, we used an ellipsometer to measure the wavelength of 633 nm.
The optical path difference of light of m was measured. These results are shown in Table 1.

Example 2 (1) Production of polycarbonate copolymer 4. The following structure was prepared in the same manner as in Example 1 (1), except that 7.0 g of 2,2'-biphenol was used instead of 4,4'-biphenol. 96 g of polycarbonate copolymer was obtained. The reduced viscosity [η sp/c) of this copolymer was 0.41 dA/g, and the Tg was 138°C.

Production and evaluation of +21 Mi product The same procedure as in Example 1 (2) was carried out except that the polycarbonate copolymer obtained in (1) above was used. Results first
Shown in the table.

Example 3 (1) Production of polycarbonate copolymer Example 1 (1)
), 4, f-biphenol and 2,2-bis(
Instead of 4-hydroxyphenyl)propane, 2,2'-
99 g of a polycarbonate copolymer having the following structure was obtained in the same manner as in Example 1 (1) except that 18.0 g of dimethyl 4°4' biphenol was used. The reduced viscosity (v sp/c) of this copolymer is 0.42 dj! /g,
Tg was 148°C.

(2) Production and evaluation of composition The same procedure as in (2) of Example 1 was carried out except that the polycarbonate copolymer obtained in (1) above was used. Results first
Shown in the table.

Example 4 (11 Production of polycarbonate copolymer (1) of Example 1
2,2-bis(4-
The same procedure was carried out except that 2,2'-bis(3-methyl-4-hydroxyphenyl)propane was used instead of hydroxyphenyl)propane, and 14.0 g of 4,4'-biphenol reacted with this oligomer was used. In the same manner as in Example 1 (11), polycarbonate copolymer 99 having the following structure was prepared.
I got g. The reduced viscosity [ηsp/c) of this copolymer is 0
43 dl/g, and Tg was 125°C.

(Production and evaluation of 21m acid product) The same procedure as in (2) of Example 1 was carried out except that the polycarbonate copolymer obtained in (1) above was used.
Shown in the table.

Example 5 To 80 parts by weight of the polycarbonate copolymer produced in Example 1 (1), polystyrene with a weight average molecular weight of 9310.000 [Idemitsu Styrene US-305, manufactured by Idemitsu Petrochemical Oil Co., Ltd.] was added as a styrene resin. The same procedure as in Example 1 (2) was carried out except that 20 parts by weight was added. The results are shown in Table 1.

Comparative Example 1 Polycarbonate with a viscosity average molecular weight of 15,000 made from 2.2-bis(4'-hydroxyphenyl)propane (manufactured by Idemitsu Petrochemical Department: Idemitsu Polycarbonate) N22
Using a composition in which 65 parts by weight of polystyrene used in Example 1 was blended with 65 parts by weight of polystyrene (00),
) was evaluated in the same way. The results are shown in Table 1.

(Margin below) Table 1 *Due to non-uniform dispersion, it does not show a constant value.

〔Effect of the invention〕

The thermoplastic resin composition of the present invention has excellent mechanical properties as well as optical properties, and is particularly characterized by low optical distortion and low birefringence, and is a material for various optical devices. For example, it can be used for still cameras, video cameras, telescopes, eyeglasses, contact lenses, prisms, optical fibers, video discs, audio discs, etc.

It is also useful as an engineering plastic and as a material for various molded products.

Claims (1)

[Claims] 1. General formula ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ [I] and ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ [II] (R^1 and R^2 in the formula are respectively Hydrogen atom, carbon number 1
-5 alkyl group, C6-10 aryl group, or C7-12 aralkyl group, R^3, R^4
are each a hydrogen atom, a halogen atom, or an alkyl group having 1 to 5 carbon atoms, and R^5 and R^6 are each a hydrogen atom or an alkyl group having 1 to 5 carbon atoms). Polycarbonate copolymer 50-9
A polycarbonate resin composition characterized in that 5 to 50 parts by weight of a styrene resin is blended to 5 parts by weight.