JPH05279460A - Aromatic polyester/polystyrene-based copolymer and its production - Google Patents

Abstract

PURPOSE:To obtain the subject copolymer with low optical strain, excellent in light transmissivity, fluidity and mechanical strength, useful for optical disks, etc., by polymerization between each specific styrenic-polymer, dihydroxyl compound and aromatic dicarboxylic acid dihalide at specified proportion. CONSTITUTION:The objective copolymer >=1000 in number-average molecular weight can be obtained by polymerization between (A) a styrenic-polymer bearing at the terminal (s) functional group reactive with acid halide group or hydroxyl group, (B) an aromatic dihydroxyl compound of the formula (R<1>-R<4> and R1'-R4' are each H, 1-5C alkyl or 1-5C alkoxy; Z is 1-15C alkylidene linkage) and (C) an aromatic dicarboxylic acid dihalide such as terephthaloyl dichloride at the weight ratio A/(B+C) of (5:95) to (95:5).

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an aromatic polyester / polystyrene copolymer and a method for producing the same, and more particularly to an optical disk, an optical fiber, which has a low birefringence and excellent fluidity and mechanical strength. TECHNICAL FIELD The present invention relates to an aromatic polyester / polystyrene copolymer useful for manufacturing optical components such as lenses and a method for manufacturing the same.

[0002]

2. Description of the Related Art Generally, an aromatic polyester resin which is excellent in transparency and suitable for a material of optical equipment has excellent heat resistance and mechanical strength, but has a problem that it has a high melt viscosity and is difficult to process. There is. In addition, there is a problem that stress distortion occurs during thermoforming such as injection molding, and the obtained product is likely to cause birefringence. Therefore, when the final product is an optical disk or optical guard protective film, this birefringence causes reading error and noise, and when the final product is an optical fiber, this birefringence is transmitted. There are problems such as causing a large loss.

As a solution to such a drawback, there is a blend of an aromatic polyester and a resin having birefringence in opposite directions. Further, it is known that a resin having no birefringence can be obtained by blending resins having birefringence in the positive and negative directions with each other (Takashi Inoue, Taku Saito, "Functional Materials," March 1987, No. 21-. 28). However, in general, a blend of an aromatic polyester and polystyrene is incompatible with each other, and even if a compatibilizing agent composed of a copolymer of the two is coexistent, its formation The product has a microphase-separated structure. Therefore, when this blend is used for applications such as magneto-optical disks where transmission of light having a relatively short wavelength (780 to 830 nm) is a problem, light scattering due to the microphase separation structure is a major problem. It was Furthermore, there is a problem that the optical homogeneity of the material is lost due to such a micro phase separation structure, and recently, a short-wavelength small green laser (wavelength 532 is used).
nm) has been developed and the requirements for optical uniformity have become even higher.

As a possibility of solving such a problem, there is, for example, an aromatic polyester / polystyrene copolymer exemplified in JP-A-58-225,113. However, even such a copolymer still has a microphase-separated structure and thus has the same problems as described above, and a resin having an increased compatibility is required. Further, as a method for producing a copolymer of this type, this publication discloses that an aromatic polyester / polystyrene resin is prepared by introducing an unsaturated group at the end of an aromatic polyester and radically copolymerizing this with a styrene monomer. Is disclosed. However, in this method, it has been attempted to utilize the polymerization reaction of the terminal unsaturated group and the styrene-based monomer, but the concentration of the terminal unsaturated group is low, and the content of the polystyrene-based polymer not copolymerized is high. However, there has been a problem that the mechanical strength of the produced polymer decreases as a result. Therefore, in an extreme case, a step of removing the non-copolymerized polystyrene polymer remaining in the produced polymer is required to maintain this mechanical property, and such a method is adopted for industrial production. It was difficult to do.

Therefore, the present inventors have solved the problems of the conventional aromatic polyester / polystyrene type copolymers, and have improved the transparency and the optical strain, and have excellent mechanical strength. As a result of diligent studies to develop a production method thereof, a copolymer composed of an aromatic polyester having a specific structure and a polystyrene resin shows excellent compatibility and is optically transparent, and further surprisingly. Is found to have better mechanical strength than conventional copolymers, and a styrene-based polymer having reactivity with an acid halide group or a hydroxyl group and a specific aromatic diol or It was found that such a copolymer can be obtained by polymerizing with an aromatic acid halide, and completed the present invention.

[0006]

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a new aromatic polyester / polystyrene copolymer suitable for a molding material for optical equipment and a method for producing the same. Further, another object of the present invention is an aromatic polyester / polystyrene system which is excellent in transparency and is optically uniform, has a small optical strain, and is excellent in fluidity and mechanical strength. It is intended to provide a copolymer and a method for producing the same.

[0007]

Means for Solving the Problems That is, the present invention provides a styrene-based repeating structural unit (A) and the following general formula (1):

[0008]

[Chemical 3]

(In the formula, R ₁ , R ₂ , R ₃ , R ₄ and R
_{1 ', R 2', R} 3 ' and R _4' represents a hydrogen atom, a monovalent radical selected from the group consisting of alkyl groups and alkoxy groups having 1 to 5 carbon atoms of 1 to 5 carbon atoms, this R _{1 to} R ₄ may be the same or different from each other, and Z is an aromatic ester repeat represented by C 1 to C 15 alkylidene bond having at least one aliphatic ring) An aromatic polyester-polystyrene-based copolymer containing a structural unit (B), wherein the structural units (A) and (B) are linked by an ester bond and / or an amide bond, wherein A: B is 98: 2 to 20:80 (molar ratio of repeating structural units) and number average molecular weight of 1.00
It is an aromatic polyester-polystyrene copolymer characterized by being 0 or more.

The present invention also relates to a styrene polymer (C) having a functional group capable of reacting with an acid halide group or a hydroxyl group at the terminal, and the following general formula (2)

[0011]

[Chemical 4]

(However, in the formula, R ₁ , R ₂ , R ₃ , R ₄ , R
_{1 ', R 2', R} 3 ' and R _4' represents a hydrogen atom, a monovalent radical selected from the group consisting of alkyl groups and alkoxy groups having 1 to 5 carbon atoms of 1 to 5 carbon atoms, this R _{1 to} R ₄ may be the same or different from each other, and Z represents an alkylidene bond having 1 to 15 carbon atoms and having at least one aliphatic ring). Aromatic polyester / polystyrene characterized by polymerizing the compound (D) and the aromatic dicarboxylic acid dihalide (E) at a ratio of C: (D + E) of 5:95 to 95: 5 (weight ratio). It is a method for producing a copolymer.

In the present invention, as the constituent of the styrene-based repeating structural unit (A), in addition to styrene,
The styrene-based monomer described below may be used, or these may be mixed. The styrene-based repeating structural unit may contain a small amount of a vinyl-based monomer such as methacrylic acid ester or acrylic acid ester. The proportion of these vinyl-based monomers is 0 to 50 mol% of the number of units in all styrene-based repeating structural units, and in the range of 0 to 20 mol% in order not to deteriorate the optical properties of the copolymer. preferable.

In the aromatic polyester structural unit present in the copolymer of the present invention, the substituents R _{1 to} R ₄ are, in addition to hydrogen atom, specifically an alkyl group having 1 to 5 carbon atoms, specifically methyl. Group, an ethyl group, a propyl group, an isopropyl group, a butyl group, a tert-butyl group, a pentyl group, and the like. Specific examples of the alkoxy group having 1 to 5 carbon atoms include a methoxy group, an ethoxy group, a propoxy group,
Examples thereof include an isopropoxy group, a butoxy group, a tert-butoxy group, and a pentoxy group.

Further, as the alkylidene group having 1 to 15 carbon atoms having at least one aliphatic ring as the bonding group Z, specifically, a cyclopentylidene group, a 2-methylcyclopentylidene group, 2,5- Examples thereof include a dimethylpentylidene group, a cyclohexylidene group, a 2,6-dimethylpentylidene group, and a 3,3,5-trimethylcyclohexylidene group, but are not limited thereto.

The aromatic polyester / polystyrene copolymer of the present invention has a styrene-equivalent number average molecular weight of 1,0.
00 or more, more preferably 1,000 or more and 500,000 or less. Number average molecular weight is 100
A copolymer having a value lower than 0 is not preferable because the physical properties as a polymer are insufficient.

Further, the aromatic polyester-polystyrene type copolymer of the present invention includes various structures depending on the composition of raw materials used, the molecular weight and the production method, and the difference in reactivity of the compounds as the reaction raw materials. For example, a random copolymer, an alternating copolymer, a block copolymer, a graft copolymer or a combination of these polymers can be used.

In the aromatic polyester / polystyrene copolymer of the present invention, the molar ratio A: B of the styrene repeating structural unit (A) and the aromatic ester repeating structural unit (B) is 98: 2 to 20:80, Preferably 80: 2
It is in the range of 0 to 30:70. If the ratio of the structural unit (A) exceeds 98, the mechanical properties of the copolymer will be insufficient,
On the other hand, if it is less than 20, the optical properties are impaired, which is not preferable.

Next, the manufacturing method of the present invention will be described. First, the styrene-based polymer (C) used for producing the aromatic polyester / polystyrene-based copolymer of the present invention comprises 1 or 2 terminal or 1 or 2 or more acid halides at the terminal and / or Alternatively, any one can be used as long as it has a functional group reactive with a hydroxyl group. For example, as a substance that reacts with an acid halide group, an amino group, a hydroxyl group, or the like can be given, and as a substance that reacts with a hydroxyl group, an acid halide group, an acid anhydride group, or the like can be given. .. The styrene-based polymer (C) preferably has the reactive group at one end or both ends of the polymer chain, and more preferably has the reactive group at both ends in order to improve its reactivity. What you have is better.

The number average molecular weight Mn of this styrene polymer (C) measured by gel permeation chromatography (hereinafter abbreviated as GPC) is 200,000 or less, preferably 150,000 or less. Mn is 200,000
If it exceeds, the polymerization reaction rate of the copolymer tends to decrease, which is not preferable. Further, it is preferable to use a styrene-based polymer (C) having a ratio (Mw / Mn) of Mn to the weight average molecular weight Mw of 4.0 or less. When a copolymer is synthesized using a styrene-based polymer having an Mw / Mn of more than 4.0, the molecular weight distribution is widened and the physical properties of the copolymer are deteriorated, which is not preferable.

Examples of the styrene-based monomer used in the production of the styrene-based polymer (C) used in the method of the present invention include styrene, o-, m-, p-methylstyrene, o-, m-, p-ethyl. Styrene, p-tert-
Alkyl-substituted styrene compounds such as butyl styrene,
o-, m-, p-chlorostyrene, dichlorostyrene,
Halogen-substituted styrene compounds such as monobromostyrene, dibromostyrene, monofluorostyrene and difluorostyrene, α-alkyl-substituted styrene compounds such as α-methylstyrene and α-ethylstyrene, and a mixture of these as appropriate may be used. Can be mentioned. Of course, the styrene-based monomer is not limited to those listed here. Further, this styrene-based polymer contains 0 to 50 mol%, preferably 0 to 20 mol% of other vinyl-based monomers such as methacrylic acid esters, acrylic acid esters, vinyl acetate, butadiene, in order to improve physical properties. It may be a copolymer of acrylonitrile or the like.

As a method for producing the styrene polymer (C) used in the present invention, known methods can be used. For example, in order to obtain a styrene-based polymer (C) having a hydroxyl group at both ends, a radical polymerization initiator having a carboxyl group is used to radically polymerize a styrene-based monomer to form a carboxyl group at the terminal. After the styrene-based polymer having the above is prepared, it is esterified with a dihydroxy compound to introduce a hydroxyl group at the terminal. Of course, the method of introducing a hydroxyl group is not limited to this method, and other known methods can be used.

As the aromatic dihydroxy compound (D) used in the present invention, the compound represented by the general formula (2) can be used. For example, 1,1-bis (4-hydroxyphenyl) cyclopentane, 1,1-bis (3,5-dimethyl-4-hydroxyphenyl) cyclopentane, 1,1-bis ( 4-hydroxyphenyl) -2-methylcyclopentane, 1,
1-bis (3,5-dimethyl-4-hydroxyphenyl) -2-methylcyclopentane, 1,1-bis (4-
Hydroxyphenyl) -2,5-dimethylcyclopentane, 1,1-bis (4-hydroxyphenyl) cyclohexane, 1,1-bis (3,5-dimethyl-4-hydroxyphenyl) cyclohexane, 1,1-bis ( 4-hydroxyphenyl) -2-methylcyclohexane, 1,
1-bis (3,5-dimethyl-4-hydroxyphenyl) -2-methylcyclohexane, 1,1-bis (4-
Hydroxyphenyl) -2,6-dimethylcyclohexane, 1,1-bis (3,5-dimethyl-4-hydroxyphenyl) -2,6-dimethylcyclohexane, 1,1
-Bis (4-hydroxyphenyl) -3,3,5-trimethylcyclohexane, 1,1-bis (3,5-dimethyl-4-hydroxyphenyl) -3,3,5-trimethylcyclohexane and the like can be mentioned. .. Also, a mixture of these can be used as appropriate.

Examples of the aromatic dicarboxylic acid dihalide (E) used in the method of the present invention include terephthalic acid dichloride, terephthalic acid dibromide, isophthalic acid dichloride, isophthalic acid dibromide and phthalic acid dichloride. .. Also, a mixture of these can be used as appropriate. Among them, a 1: 1 mixture of terephthalic acid dichloride and isophthalic acid dichloride is particularly preferable. If necessary, naphthalene dicarboxylic acid dihalide can be used up to 30 mol% based on the aromatic dicarboxylic acid.

Use of a styrene-based polymer (C), an aromatic dihydroxy compound (D), and an aromatic dicarboxylic acid dihalide (E), which are used for producing the aromatic polyester / polystyrene-based copolymer of the present invention. The proportion can be appropriately changed, but in order to obtain suitable optical and mechanical properties, the content of the styrenic polymer is preferably 10 to 90% by weight. For this purpose, the styrenic polymer (C Of the aromatic dihydroxy compound (D) and the aromatic dicarboxylic acid dihalide (E), that is, C: (D + E) in a weight ratio of 5:
It is desirable to be within the range of 95 to 95: 5. If the styrene-based polymer (C) is less than 10% by weight, the birefringence of the obtained copolymer tends to be high, and if it is more than 90% by weight, the mechanical properties of the obtained copolymer are deteriorated, which is not preferable. Further, the amounts of the aromatic dihydroxy compound and the aromatic dicarboxylic acid dihalide are used so that they are almost equimolar, but since the styrene polymer has a reactive group with an acid halide or a hydroxyl group, It is preferable to adjust the amount of the aromatic dicarboxylic acid dihalide or aromatic dihydroxy compound to be used in an amount corresponding to the number of moles.

The method for producing the aromatic polyester / polystyrene copolymer of the present invention is not particularly limited, and for example, a known method such as an interfacial polymerization method or a solution polymerization method may be used. You can

For example, as an interfacial polymerization method, an alkaline aqueous solution of an aromatic dihydroxy compound, a styrene-based polymer polymer having the above-mentioned reactive group at the end dissolved in an organic solvent incompatible with water, and an aromatic dicarboxylic acid dihalide are used. It is carried out by mixing and stirring the mixture. The alkali used in this interfacial polymerization method is preferably sodium hydroxide or potassium hydroxide, and the organic solvent does not react with the styrene-based polymer and aromatic dicarboxylic acid dihalide, and the styrene-based polymer, aromatic dicarboxylic acid dihalide and Any solvent that is a good solvent for any of the resulting aromatic polyester / polystyrene-based copolymers may be used, and those that are not completely compatible with water are desirable. Examples of such an organic solvent include halogenated hydrocarbons such as dichloromethane, chloroform, 1,2-dichloroethane, and 1,1,2,2-tetrachloroethane, chlorobenzene, o-, m-, p-.
Examples thereof include aromatic halogen compounds such as dichlorobenzene, aromatic hydrocarbons such as benzene, toluene and xylene, and a mixture of them. Further, in this interfacial polymerization method, a quaternary ammonium salt such as trimethylbenzylammonium halide, triethylbenzylammonium halide, tributylbenzylammonium halide or tetrabutylammonium halide may be added to accelerate the polymerization reaction.
As the halide, Cl, Br, I and the like are preferable. The interfacial polymerization reaction is carried out at a temperature of 2 to 50 ° C., preferably 5 to 50 ° C. with stirring for a polymerization time of about 5 minutes to 8 hours.

In the solution polymerization method, the aromatic dihydroxyl compound and a mixture of a styrene polymer having the reactive group at the terminal and an aromatic dicarboxylic acid dihalide are mixed and stirred in an organic solvent in the presence of an alkali. Done by. Examples of the alkali used in this solution polymerization include sodium hydroxide, potassium hydroxide, and inorganic basic compounds such as calcium hydroxide, triethylamine,
Tertiary amines such as tributylamine and pyridine, and D
BU [1,8-diazabicyclo (5,4
0) undec-7-ene] and DBN [1,5-di]
azabicyclo (4,3,0) nonene-
5] or the like is preferably used as an organic strong basic compound, and
The solvent does not react with the styrene-based polymer and the aromatic dicarboxylic acid dihalide, and any of the aromatic dihydroxyl compound, the styrene-based polymer, the aromatic dicarboxylic acid dihalide and the aromatic polyester / polystyrene-based copolymer produced. Is not particularly limited as long as it is a good solvent. Examples of these include aromatic hydrocarbon compounds such as benzene, toluene and xylene, halogenated hydrocarbons such as dichloromethane, 1,2-dichloroethane, chloroform, chlorobenzene and dichlorobenzene, dioxane, tetrahydrofuran and dimethylformamide. Examples thereof include dimethyl sulfoxide, pyridine, and the like, or a mixture thereof.
Further, in order to adjust the molecular weight, o, m, p-cresol, o, m, p-phenylphenol, p-tert-
It is also possible to add monofunctional phenolic compounds such as butylphenol.

As the method for isolating and purifying the desired copolymer produced from the polymerization solvent after the completion of such interfacial polymerization or solution polymerization reaction, various known methods can be adopted. For example, after completion of the polymerization, after performing a washing operation such as filtration or extraction as necessary, the polymerization solution containing the copolymer is a solvent such as acetone or methanol, which does not dissolve the copolymer and dissolves unreacted substances. A method of injecting the solution into the solution to precipitate a copolymer, filtering the solution, and drying it to isolate a desired copolymer can be mentioned. Furthermore, when it is necessary to remove the non-copolymerized styrene-based polymer in the generated polymer, a solvent that dissolves only the styrene-based polymer such as cyclohexane is used to selectively dissolve and remove only the styrene-based polymer. You may let me.

The aromatic polyester / polystyrene copolymer of the present invention has good fluidity and high transparency,
It is also suitable for use as a material for optical devices with low birefringence by itself, but it is added to a blend of an aromatic polyester and a styrene polymer to enhance the tensile strength, flexural strength, flexural modulus, etc. of this blend. Can be used as a compatibilizing agent.

[0031]

EXAMPLES The present invention will be described in more detail with reference to reference examples and examples. Reference Examples 1-2 [Production Example of Styrene-based Polymer (C ′)] 4,4′-azobis-4-cyanovaleric acid (ACVA) was used as a polymerization initiator, and 100 parts by weight of styrene was heated to 90 ° C.
Radically polymerized. ACVA was dissolved in 1,4-dioxane and continuously added during the polymerization as well as at the beginning of the polymerization. ACVA initially added and AC continuously added
By changing the concentration of VA, the styrene-based polymer (C ′) shown in Table 1 was obtained. In addition, the molecular weight was measured using a GPC measuring device HLC-802A manufactured by Toyo Soda Co., Ltd. The average number of carboxyl groups contained in one molecule of the polymer was measured by neutralizing titration of the polymer solution with a sodium hydroxide solution using an automatic titrator GT-05 type manufactured by Mitsubishi Kasei Kogyo Co., Ltd.

Reference Examples 3 to 4 [Production of styrene-based polymer (C) having a hydroxyl group at the end from styrene-based polymer (C ')] Reference Example 1
To 100 parts by weight of the styrene-based polymer (C ') prepared in 2 to 2 are dissolved in dichloromethane, and 3 to 7 parts by weight of bisphenol A are added to esterify the styrene-based polymer (C) to prepare a styrene-based polymer (C) having a terminal hydroxyl group. did. The amount of terminal hydroxyl groups was determined by quantifying unreacted carboxyl groups in the same manner as in Reference Examples 1-2.
The results are shown in Table 2.

[0033]

[Table 1]

[0034]

[Table 2]

Examples 1-2 Using a round-bottomed flask equipped with a stirrer, 100 parts by weight of the styrene-based polymer (C) produced in Reference Examples 3-4 and 29 parts by weight of each of terephthalic acid dichloride and isophthalic acid dichloride were used. It was dissolved in 1000 parts by weight of dichloromethane, 0.1 part by weight of calcium hydroxide and 0.01 part by weight of triethylamine were added as catalysts, and the mixture was stirred for 1 hour to convert the polystyrene terminal into acid chloride. Then
Into another round-bottomed flask equipped with a stirrer, 583 parts by weight of 1N-sodium hydroxide aqueous solution was charged, and bisphenol Z7 was added.
5.2 parts by weight were dissolved, and 0.05 part by weight of tri-n-butylbenzylammonium chloride was added as a catalyst. The acid chloride solution prepared above was added to the solution thus prepared, and stirred for 2 hours after completion of the addition to carry out interfacial polymerization. After the polymerization was completed, the aqueous phase and the organic phase were separated, the organic phase was neutralized with 630 parts by weight of a 1N-acetic acid aqueous solution, and then washed, and only this organic phase was extracted and dissolved in 1,000 parts by weight of chloroform. did. This chloroform solution was filtered through a 1 μm filter and then 10,000
The polymer was precipitated by adding it to parts by weight of methanol. The polymer precipitate obtained was filtered off, washed with methanol and dried in a vacuum drier.

Examples 3 to 4 100 parts by weight of the styrenic polymer (C) produced in Reference Examples 3 to 4, 75.2 parts by weight of bisphenol Z, 2.5 parts by weight of triethylamine, and dichloromethane were placed in a round-bottomed flask equipped with a stirrer. Charge with 800 parts by weight to dissolve,
Further, while adding 55 parts by weight of calcium hydroxide and suspending it, a solution prepared by dissolving 29 parts by weight of each of terephthalic acid dichloride and isophthalic acid dichloride in 200 parts by weight of dichloromethane was added dropwise. After completion of dropping, the solution was polymerized by stirring for 2 hours. After the completion of the polymerization, the polymerization solvent was neutralized with 630 parts by weight of a 1N-acetic acid aqueous solution and washed. The dichloromethane solution was filtered using a 1 μm filter and then added to 10000 parts by weight of methanol,
The polymer was precipitated. The polymer precipitate obtained was filtered off, washed with methanol and dried in a vacuum drier.

The average molecular weight of the thus obtained polymer was measured in the same manner as in Reference Examples 1 and 2 above. The results are shown in Table 3. The styrene-based polymer (C) used in Examples 1-2 and 3-4 is the styrene-based polymer (C) synthesized in Reference Examples 3-4, respectively. Further, the polymers polymerized in Examples 1 to 4 were dissolved in methylene chloride to give 2
As a 0% by weight solution, Automa manufactured by Yasuda Seiki Co.
tic film applicator No542
-AB-S was used to make a 100 μm thick film, and this film was left for 12 hours at room temperature,
The solvent was removed by drying for 12 hours in a vacuum dryer at ℃.
The film thus obtained was subjected to hot air circulation uniaxial stretching device manufactured by Satake Chemical Machinery Co., Ltd.
The film was stretched at 20 to 10% by 10%, and the birefringence of the film was measured with an optical-pol polarizing microscope (wavelength 546 nm) manufactured by Nikon Corporation. The results are shown in Table 4. further,
The light transmittances at 830 and 530 nm were measured with a spectrophotometer U3120 manufactured by Hitachi, Ltd. The results are shown in Table 5.

Comparative Example 1 203 g of mixed acid chloride obtained by mixing terephthalic acid dichloride and isophthalic acid dichloride in a molar ratio of 1: 1 according to the example described in JP-A-58-157844. Methacrylic acid chloride 4.
18 g of methylene chloride solution and bisphenol A233
A polyester having a methacryl group at the end was produced from the aqueous sodium hydroxide solution (g) by an interfacial polymerization method.
The number average molecular weight Mn was measured using GPC in the same manner as in the above reference example.
The result of measurement was 4,000. The polyester and the styrene monomer were heated and mixed (130 ° C.) in a nitrogen atmosphere at a weight ratio of 1: 1 and polymerized for 20 hours.
The produced polymer is recovered in the same manner as in Examples 1 to 3,
The molecular weight and composition of the copolymer and the content of polystyrene not copolymerized were measured. The results are shown in Table 3. Further, the product polymerized by this method was formed into a film in the same manner as in Example 1.

Comparative Example 2 A commercially available aromatic polyester [U polymer "U-
100 ", manufactured by Unitika Ltd.] was used to measure the birefringence in the same manner as in Examples 1 to 3. The results are shown in Table 4.

Comparative Example 3 Commercially available aromatic polyester (U polymer "U-
100 ", manufactured by Unitika Ltd.) and 10 g of polystyrene obtained in Reference Example 3 were dissolved in methylene chloride to obtain a 20% by weight solution. Using this solution, a cast film was prepared in the same manner as in the example, and light transmission was performed. The rate was measured and the results are shown in Table 5.

From the results of the above Examples and Comparative Examples, the following matters were found. From the results of Examples 1 to 4, an aromatic polyester-polystyrene copolymer can be produced by the production method of the present invention. From the comparison between Examples 1 to 4 and Comparative Example 2, the aromatic polyester / polystyrene copolymer of the present invention can reduce the birefringence even under stretching. From the comparison between Examples 1 to 4 and Comparative Examples 1 and 3, the aromatic polyester-polystyrene copolymer of the present invention has excellent light transmittance.

[0042]

[Table 3]

[0043]

[Table 4]

[0044]

[Table 5]

[0045]

EFFECT OF THE INVENTION The aromatic polyester / polystyrene type copolymer of the present invention is superior in light transmittance as compared with the conventional one, and has a low content of the non-copolymerized styrene type polymer. And its birefringence is low. Therefore,
The aromatic polyester / polystyrene-based copolymer of the present invention can be used as a good material for optical devices, and
Addition to the blend of aromatic polyester and styrenic polymer to increase compatibility, tensile strength of the blend,
It can also be used for the purpose of enhancing bending strength and bending elastic modulus. Further, according to the method of the present invention, such an aromatic polyester / polystyrene copolymer can be easily produced.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Kenji Yasue Kenji Yasue 23 Uji Kozakura, Uji City, Kyoto Prefecture, Unitika stock company Central Research Institute (72) Inventor Akio Motoyama 23 Uji Kozakura, Uji City Kyoto Prefecture, Unitika stock company Central Research Laboratory (72) Inventor Takamasa Owaki 23 Uji Kozakura, Uji City, Kyoto Prefecture, Unitika Co., Ltd. Central Research Laboratory (72) Inventor Masao Kimura 1618 Ida, Nakahara-ku, Kawasaki-shi, Kanagawa Nippon Steel Corporation Company Advanced Technology Laboratory (72) Inventor Koichi Fujishiro 1618 Ida, Nakahara-ku, Kawasaki-shi, Kanagawa, Nippon Steel Corporation Advanced Technology Laboratory (72) Inventor Hiroshi Oishi 1618 Ida, Nakahara-ku, Kawasaki-shi, Kanagawa Nippon Steel Co., Ltd., Advanced Technology Research Laboratories (72) Inventor Shinji Inaba 1618 Ida, Nakahara-ku, Kawasaki-shi, Kanagawa, Shin This made Steel Co., Ltd. Advanced Technology in the Laboratory

Claims (2)

[Claims] 1. A styrene-based repeating structural unit (A),
The following general formula (1) (However, in the formula, R ₁ , R ₂ , R ₃ , R ₄ , R ₁ ′, R ₂ ′, R
₃ 'and R _4' is selected from the group consisting of a hydrogen atom, an alkyl group and alkoxy group having 1 to 5 carbon atoms of 1 to 5 carbon atoms 1
A valent group, wherein R _{1 to} R ₄ may be the same or different from each other, and Z represents an alkylidene bond having 1 to 15 carbon atoms and having at least one aliphatic ring). An aromatic polyester-polystyrene-based copolymer comprising an aromatic ester repeating structural unit (B) represented, wherein each structural unit (A) and (B) are linked by an ester bond and / or an amide bond. There
A: B is 98: 2 to 20:80 (molar ratio of repeating structural units), and the number average molecular weight is 1,000 or more, The aromatic polyester-polystyrene type copolymer characterized by the above-mentioned. 2. A styrenic polymer (C) having a terminal functional group capable of reacting with an acid halide group or a hydroxyl group.
And the following general formula (2): (However, in the formula, R ₁ , R ₂ , R ₃ , R ₄ , R ₁ ′, R ₂ ′, R
₃ 'and R _4' is selected from the group consisting of a hydrogen atom, an alkyl group and alkoxy group having 1 to 5 carbon atoms of 1 to 5 carbon atoms 1
A valent group, wherein R _{1 to} R ₄ may be the same or different from each other, and Z represents an alkylidene bond having 1 to 15 carbon atoms and having at least one aliphatic ring). Aromatic dihydroxyl compound represented (D)
And an aromatic dicarboxylic acid dihalide (E), C:
A method for producing an aromatic polyester-polystyrene copolymer, which comprises polymerizing at a ratio of (D + E) of 5:95 to 95: 5 (weight ratio).