JPH07278284A - Copolycarbonate - Google Patents

Abstract

PURPOSE:To obtain a copolycarbonate resin exhibiting excellent optical characteristics and thermal resistance by using bisphenols of specific structures as the starting material. CONSTITUTION:A copolycarbonate resin having repeating units represented by formulae I and II in a molar ratio of 90/10 to 5/95. It is preferred that the resin have a number-average molecular weight of 20,000 to 200,000. A bisphenol fluorene represented by formula I can be obtained by the condensation of phenol with 9-fluorenone as the starting material. A bisphenol Z represented by formula II can be obtained by the condensation of phenol with cyclohexanone as the starting material. The copolymer is obtained from the mixture of the above bisphenols preferably by the phosgene method.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a copolycarbonate resin containing bisphenol fluorene and bisphenol Z as bisphenol components. More specifically, it has excellent heat resistance, is optically homogeneous, and has a high refractive index and a low birefringence. The present invention relates to a novel polycarbonate resin that can be suitably used in the field of optical device elements and in the field of electrophotographic photoreceptors because of its high solubility.

[0002]

2. Description of the Related Art Conventionally, as aromatic diols, 2,
Polycarbonate containing 2-bis (4-hydroxyphenyl) propane (bisphenol A) as a main raw material has been used in a wide range of fields because of its excellent transparency, impact resistance, and heat resistance. However, many studies have been carried out in order to impart higher heat resistance. In JP-A-62-27426, a specific amount of a specific bisphenol compound is introduced to improve both moldability and heat resistance. Attempts have been proposed to satisfy the requirements in a well-balanced manner.

On the other hand, a polycarbonate resin has been conventionally used for an organic polymer material used for an optical device such as an optical disc or an electrophotographic photosensitive member. However, the polycarbonate resin has a large birefringence and is used as an optical material. Not only has a fatal defect, but also when a film is produced by a casting method for use in an electrophotographic photoreceptor, poor appearance of the film due to poor solubility is a problem. It was

JP-A-59-71057 proposes to use bisphenol Z polycarbonate as a binder resin for a charge transport layer of an electrophotographic photoreceptor. However, even when the polycarbonate of bisphenol Z is used as the binder resin of the charge transport layer, the problem of cracking of the charge transport layer when the photoreceptor is repeatedly used has not been solved.

For the purpose of solving such a problem, Japanese Patent Laid-Open No. 63-40159 proposes that the polycarbonate resin of bisphenol Z has an average molecular weight of 30,000 or more, but it has optical properties, heat resistance, solubility, and There has been no polycarbonate resin satisfying all of the moldability and the like, and development of a new polycarbonate that solves these problems has been desired.

[0006]

DISCLOSURE OF THE INVENTION An object of the present invention relates to a novel polycarbonate resin, and in particular, since it is optically homogeneous and excellent in heat resistance, optical anisotropy is reduced even in a molded product, It is an object of the present invention to provide a polycarbonate resin having a small birefringence, an excellent solubility, and a homogeneous molded product obtained by molding by a casting method.

[0007]

Means for Solving the Problems As a result of extensive studies to solve the above problems, the present inventors have found that a specific novel polycarbonate resin obtained from a bisphenol having a specific structure as a raw material Beyond the difference, they have found that they are polymers having excellent optical properties and excellent heat resistance, and have completed the present invention based on these findings.

That is, the present invention has repeating units represented by the following formulas (I) and (II),
The present invention provides a copolymeric polycarbonate resin characterized in that the molar ratio of the repeating unit (I) to the repeating unit (II) is 90:10 to 5:95.

[0009]

[Chemical 3] (I)

[0010]

[Chemical 4] (II)

The bisphenolfluorene represented by the formula (I) used in the present invention can be produced by condensing phenol with 9-fluorene as a raw material. In addition, the polycarbonate using this is U.S.P. S. Patent
3,546,165 proposed as a high heat resistant polyester.

On the other hand, the bisphenol Z represented by the formula (II) used in the present invention can be produced by condensing phenol with cyclohexanone as a raw material.

The copolymer of the present invention can be easily produced from a mixture of bisphenolfluorene and bisphenol Z by a known method. For example, in the phosgene method,
The polymer can be obtained by reacting the mixed bisphenol with phosgene in a solvent such as a chlorine-based solvent, and in the transesterification method, the mixed bisphenol and dimethyl carbonate are reacted at a high temperature under a high vacuum to produce a secondary polymer. The formed methanol can be removed to obtain a polymer. Among these methods, the phosgene method can easily obtain a polymer having a high degree of polymerization.

The copolymerized polycarbonate resin of the present invention is a copolymer having the repeating unit (I) and the repeating unit (II), the molar ratio of which is 90:10 to 5:95. Particularly preferred is a copolymer in which the molar ratio of the repeating unit (I) and the repeating unit (II) is in the range of 80:20 to 10:90. If the repeating unit (I) exceeds 90 mol%, the polymer lacks in polymerizability and a sufficient polymer cannot be obtained. If it is less than 5 mol%, sufficient heat resistance and optical properties cannot be obtained.

The number average molecular weight of the polycarbonate having the repeating units represented by (I) and (II) is 20,000 to 20.
10,000, more preferably 30,000 to 150,000. If the molecular weight of the polycarbonate is 20,000 or less, the polymer becomes brittle, which is not preferable. On the other hand, when it is 200,000 or more, the viscosity becomes too high and the moldability is deteriorated, which is not preferable. Further, it is not realistic to industrially obtain a polymer having a polymerization degree higher than this.

If necessary, the copolymerized polycarbonate of the present invention contains an antioxidant, a heat stabilizer, an ultraviolet absorber, a release agent, a dye, an antistatic agent, as long as the object of the present invention can be achieved. A plasticizer, an antifogging agent, a flame retardant, etc. can be added.

[0017]

EXAMPLES The present invention will be described below in more detail with reference to Examples and Comparative Examples, but the present invention is not limited to these Examples. The evaluation of the resin is
The procedure was as follows.

Measurement of Average Molecular Weight The average molecular weight was measured by polystyrene conversion using a GPC column “SHODEX GPC KD-80M” manufactured by Showa Denko KK.

Measurement of Birefringence Birefringence was measured using a polarization microscope and compensator manufactured by Olympus Optical Co., Ltd.

Example 1.500 ml five-necked flask (stirring device, reflux device, gas introducing device, dropping device, pH
(With monitor), 85 ml of dichloromethane, 3.07 g (8.76 mmol) of bisphenolfluorene,
Bisphenol Z 9.40 g (35.04 mmol),
p-cumylphenol 0.12 g, triethylamine 1
ml was added, and the pH of the aqueous phase was adjusted to around 11 with an 18N-NaOH aqueous solution. Phosgene was blown at 0.5 g / min, and during the reaction, the pH was adjusted to 10.5-11.5 with the above-mentioned NaOH aqueous solution. After the reaction, the organic phase was washed with hydrochloric acid and water and then put into methanol.
The precipitate was filtered, washed with methanol and hexane, and dried. As a result, a polycarbonate having an average molecular weight of 30,000 and a glass transition temperature Tg of 198 ° C. was obtained. The polycarbonate was dissolved in dichloromethane and a film was formed by a casting method. It was tough and optically homogeneous. The birefringence was 43 × 10 ⁻⁶ . The varnish dissolved in the solvent was stable even after storage for 1 month.

Comparative Example 1.500 ml five-necked flask (stirring device, reflux device, gas introducing device, dropping device, pH
85 ml of dichloromethane, 10.00 g (43.8 mmol) of bisphenol A, 0.12 g of p-cumylphenol and 1 ml of triethylamine were added to a monitor), and the pH of the aqueous phase was adjusted to around 11 with an 18N-NaOH aqueous solution. Phosgene was blown at 0.5 g / min, and during the reaction, the pH was adjusted to 10.5-11.5 with the above-mentioned NaOH aqueous solution. After the reaction, the organic phase was washed with hydrochloric acid and water and then put into methanol. The precipitate was filtered, washed with methanol and hexane, and dried. As a result, a polycarbonate having an average molecular weight of 32,000 and a glass transition temperature Tg of 148 ° C. was obtained. The polycarbonate was dissolved in dichloromethane and a film was formed by a casting method, but it was difficult to dissolve in a solvent, and the film surface had a citrus-like portion. Birefringence is 160 × 1
0 ^-6, varnish dissolved in a solvent, one month after storage,
Gelation was observed.

[0022]

According to the present invention, there can be obtained a copolycarbonate which is superior in optical characteristics to the conventional polycarbonate resin, is optically homogeneous, and has a small birefringence index of a molded product. Furthermore, the obtained product was excellent in heat resistance, rich in solubility, and strong and homogeneous as a film.
Polycarbonate resins having these advantages are
It is suitable as a binder material for magneto-optical disks and electrophotographic photoreceptors.

Claims (2)

[Claims] 1. A repeating unit represented by the following formulas (I) and (II), wherein the molar ratio of the repeating unit (I) to the repeating unit (II) is 90:10 to 5:
95 is a copolymerized polycarbonate resin. [Chemical 1] (I) (II) 2. The copolymerized polycarbonate according to claim 1, wherein the polycarbonate having repeating units represented by (I) and (II) has a number average molecular weight of 20,000 to 200,000.