JPH0597988A - Method for producing wholly aromatic polyester polystyrenic copolymer - Google Patents

Abstract

PURPOSE:To obtain a polyester.polystyrenic copolymer suitable for optical device materials by subjecting an end amino group-containing styrenic polymer, an aromatic dihydroxy compound and an aromatic dicarboxylic acid dihalide to interfacial polymerization. CONSTITUTION:(A) A styrenic polymer containing an amino group at an end, preferably amino groups at both ends, preferably one having 1,000-200,000 number-average molecular weight, (B) an aromatic dihydroxy compound (preferably bisphenol A) and (C) an aromatic dicarboxylic acid dihalide (preferably a mixture of terephthalic acid dichloride and isophthalic acid dichloride in a ratio of 1:1) are subjected to interfacial polymerization in a ratio of A/(B+D) of 20/80-80/20 (weight ratio) by blending an aqueous solution of the component B with a mixture of the components A and C dissolved in an organic solvent (e.g. dichloromethane) having no compatibility with water to give a wholly aromatic polyester polystyrenic copolymer having a low content of styrenic polymer not copolymerized, excellent mechanical strength and low double refraction.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a wholly aromatic polyester / polystyrene copolymer. More specifically, the present invention relates to a method for producing a wholly aromatic polyester / polystyrene copolymer having a low birefringence, which is useful for forming optical components such as optical disks, optical fibers, and lenses.

[0002]

2. Description of the Related Art Generally, wholly aromatic polyester resins, which are excellent in transparency and suitable for optical materials, have excellent heat resistance and mechanical strength, but have a high melt viscosity. There is a problem that it is difficult to process. In addition, there is a problem that stress distortion occurs during thermoforming processing such as injection molding, and the obtained product is likely to cause birefringence. Therefore, if the final product is an optical disk or optical guard protective film, the birefringence may cause a read error or noise, and if the final product is an optical fiber, the birefringence may cause a large transmission loss. There are problems such as

As means for solving such a problem, a wholly aromatic polyester resin (hereinafter sometimes abbreviated as PAr) and a polystyrene resin having birefringence in positive and negative opposite directions (hereinafter abbreviated as PS) are used. Sometimes)) to reduce birefringence, or by blending PS and PAr and adding a resin in which PS and PAr are chemically bonded as a compatibilizer. Methods of reducing birefringence are known. As a method for producing the above-mentioned wholly aromatic polyester / polystyrene copolymer,
JP 58-157,844 or JP 58
Japanese Patent Laid-Open No. 225,113 discloses a production method in which an unsaturated group is introduced into the terminal of wholly aromatic polyester, and the unsaturated group is radically copolymerized with a styrene-based monomer. However, in this method, at the same time as the radical copolymerization reaction between the terminal unsaturated group and the styrene-based monomer, a polymerization reaction between the styrene-based monomers occurs, so that the content of the polystyrene-based polymer not copolymerized increases. There is a problem that the mechanical properties of the produced polymer deteriorate. Therefore, in an extreme case, in order to maintain mechanical properties, a step of removing the uncopolymerized styrene-based polymer remaining in the produced polymer is required, and such a method is applied to industrial production. It was difficult. Furthermore, JP-A-1
No. 129,011 discloses that an allylamine-modified styrene polymer obtained by radically copolymerizing a styrene monomer and allylamine and a wholly aromatic polyester compound are melt-mixed at a high temperature (260 to 340 ° C.). A method for producing a wholly aromatic polyester / polystyrene copolymer is disclosed. In this production method, the polyester chain is cleaved by the action of the amino group to react the allylamine-modified styrene-based polymer with the wholly aromatic polyester, so that the chain of the wholly aromatic polyester unit in the obtained polymer is shortened, There is a problem that it is difficult to obtain a polymer having sufficient strength. Further, there is a problem that the obtained polymer is colored because it requires melt mixing at high temperature.

[0004]

Therefore, the inventors of the present invention can solve various problems of the above-mentioned conventional method for producing a wholly aromatic polyester / polystyrene-based copolymer, and the optical device can be used. As a result of earnest research on a method capable of producing a wholly aromatic polyester / polystyrene copolymer suitable as a molding material for a resin, a styrene polymer having an amino group at a terminal of a molecule and an aromatic dicarboxylic acid dihalide The inventors have found that a desired wholly aromatic polyester / polystyrene copolymer can be obtained by subjecting an aromatic dihydroxy compound and an aromatic dihydroxy compound to interfacial condensation polymerization at a predetermined ratio, and completed the present invention. Therefore, the object of the present invention is excellent in transparency and small optical distortion,
Moreover, it is intended to provide a method for producing a wholly aromatic polyester / polystyrene copolymer which is excellent in fluidity and mechanical strength and is particularly suitable as a molding material for optical equipment.

[0005]

That is, the present invention provides a styrene polymer (A) having an amino group at a terminal, an aromatic dihydroxy compound (B) and an aromatic dicarboxylic acid dihalide (C) ( A) / [(B) + (C)] is 2
This is a method for producing a wholly aromatic polyester / polystyrene copolymer in which interfacial polymerization is carried out at a ratio of 0/80 to 80/20 (weight ratio).

The present invention will be described in detail below. The styrenic polymer (A) used in the present invention has a terminal 1
One or two amino groups and one or two or more amino groups in the middle are preferable, but one having one or both amino groups is preferable, in order to improve reactivity. More preferably, those having an amino group at both ends are used. The number average molecular weight Mn of this styrene-based polymer measured by gel permeation chromatography (hereinafter abbreviated as GPC) is 1,000 or more and 20
It is preferably 50,000 or less. This Mn is 1,
If it is less than 000, the physical properties of the polymer become insufficient, and conversely, if this Mn exceeds 200,000, the polymerization reaction rate of the polymer tends to decrease, which is not preferable. Further, the ratio of Mn to the weight average molecular weight Mw (Mw / M
It is preferable to use a styrene polymer (A) having n) of 4.0 or less. When a polymer is synthesized using a styrene-based polymer having Mw / Mn of more than 4.0, the resulting polymer has a broad molecular weight distribution and is deteriorated in physical properties, which is not preferable.

As the styrene-based monomer for synthesizing the styrene-based polymer (A) used in the method of the present invention,
Other than styrene, for example, o-, m-, p-methylstyrene, o-, m-, p-ethylstyrene, p-tert.
-Alkyl-substituted styrene compounds such as butyl styrene,
o-, m-, p-chlorostyrene, dichlorostyrene,
Examples of the halogen-substituted styrene compounds such as monobromostyrene, dibromostyrene, monofluorostyrene, difluorostyrene, α-methylstyrene, α-alkyl substituted styrene compounds such as α-ethylstyrene and the like, and a mixture thereof are appropriately mixed. Be done. Of course, the styrene-based monomer is not limited to those listed here. In addition, the styrene-based polymer contains 0 to 50% by weight of other vinyl-based monomers such as methacrylic acid esters, acrylic acid esters, vinyl acetate, butadiene, and acrylonitrile in order to improve its physical properties. It may be polymerized.

As a method for synthesizing the styrene polymer (A) used in the present invention, a known method can be used. For example, radical polymerization of a styrene-based monomer using a radical polymerization initiator having a carboxyl group to prepare the styrene-based polymer having a carboxyl group at the terminal, followed by amidation reaction with a diamine compound at the terminal A method of introducing an amino group can be mentioned. Of course, the method of introducing an amino group is not limited to the above method, and other known methods can be adopted.

Examples of the aromatic dihydroxy compound (B) used in the present invention include 2,2-bis (4-hydroxyphenyl) propane (hereinafter abbreviated as "bisphenol A"), tetramethylbisphenol A, tetrabromo. Bisphenol A, bis (4-hydroxyphenyl) -p-diisopropylbenzene, hydroquinone,
Resorcinol, 4,4′-dihydroxybiphenyl and the like and a mixture of these appropriately mixed can be mentioned, and among these, bisphenol A is particularly preferable.

Examples of the aromatic dicarboxylic acid dihalide (C) used in the method of the present invention include terephthalic acid dichloride, terephthalic acid dibromide, isophthalic acid dichloride, isophthalic acid dibromide, phthalic acid dichloride and the like. The mixture may be appropriately mixed in the range of 25 to 75%, and among these, a 1: 1 mixture of terephthalic acid dichloride and isophthalic acid dichloride is particularly preferable.

In the present invention, the styrene polymer (A)
The ratio of the aromatic dihydroxy compound (B) and the aromatic dicarboxylic acid dihalide (C) to be used can be appropriately changed, but in order to obtain suitable optical and mechanical properties, the content of the styrene polymer is 20 To 80% by weight, and for this purpose, the ratio of the weight of the styrene-based polymer (A) to the total weight of the aromatic dihydroxy compound (B) and the aromatic dicarboxylic acid dihalide (C), that is, (A )
/ [(B) + (C)] (weight ratio) 20:80 to 80:
It is desirable to set it within the range of 20. When the amount of the styrene-based polymer is less than 20% by weight, the birefringence of the obtained polymer tends to be high. On the contrary, when it is more than 80% by weight, the mechanical properties of the obtained polymer 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. It is preferred to use the dicarboxylic acid dihalide in excess with respect to the aromatic dihydroxy compound.

The interfacial polymerization method used in the present invention is carried out by dissolving an aromatic dihydroxy compound (B) in an alkaline aqueous solution, a styrene polymer (A) having an amino group at the end dissolved in an organic solvent incompatible with water, and It is carried out by mixing and stirring the mixture with the aromatic dicarboxylic acid dihalide (C). As the alkaline aqueous solution, sodium hydroxide aqueous solution and potassium hydroxide aqueous solution are preferably used. Also,
The organic solvent does not react with the styrene polymer (A) and the aromatic dicarboxylic acid dihalide (C), but the styrene polymer (A), the aromatic dicarboxylic acid dihalide (C) and the wholly aromatic polyester produced. It is desirable that it is a good solvent for any of the polystyrene-based copolymers and that it is not completely compatible with water. Examples of such an organic solvent include dichloromethane, chloroform, 1,2-
Dichloroethane, halogenated hydrocarbons such as 1,1,2,2-tetrachloroethane, chlorobenzene, o
Examples thereof include aromatic halogen compounds such as-, m-, p-dichlorobenzene, aromatic hydrocarbons such as benzene, toluene, and xylene, and a mixture of them. This interfacial polymerization reaction is carried out at a temperature of 2 to 50 ° C., preferably 5 to 50 ° C. under stirring for a polymerization time of about 5 minutes to 8 hours.

In the interfacial polymerization method of the present invention, a quaternary ammonium salt such as trimethylbenzylammonium halide, triethylbenzylammonium halide, tributylbenzylammonium halide or tetrabutylammonium halide may be added to accelerate the polymerization reaction. Good. As the halide, Cl, Br, I and the like are preferable. Further, in order to adjust the molecular weight, o, m, p-cresol, o, m, p-phenylphenol, p-te
It is also possible to add monofunctional phenolic compounds such as rt-butylphenol.

Various known methods can be adopted for the isolation and purification of the polymer after the completion of the polymerization reaction. For example,
After completion of the polymerization, it is allowed to stand still or mechanically separated using a centrifuge or the like into an aqueous phase containing an inorganic salt and an organic phase containing a polymer, and the organic phase containing the polymer is filtered or extracted as necessary. The method of isolating the target polymer by adding the solvent to a solvent such as acetone or methanol to precipitate the polymer, filtering and drying the polymer is performed. When it is necessary to remove the non-copolymerized styrene-based polymer in the produced polymer, it may be selectively dissolved and removed by using a solvent that dissolves only the styrene-based polymer such as cyclohexane.

The styrene-equivalent number average molecular weight Mn of the wholly aromatic polyester / polystyrene copolymer synthesized according to the present invention is 1,000 to 300,0 as measured by GPC.
00 is preferable. If Mn is less than 1,000, mechanical properties tend to be insufficient, and Mn is 300,000.
When it exceeds 0, it is not preferable because it is difficult to remove the polymerization solvent because the polymer formed becomes a gel and the melt viscosity of the polymer increases, so that the molding processability also remarkably decreases.

The wholly aromatic polyester synthesized according to the present invention
Polystyrene-based copolymers have good fluidity, high transparency, and are preferably used alone as a material for optical devices with low birefringence, but they are blends of wholly aromatic polyesters and styrene-based polymers. Can also be used to increase the compatibility and enhance the tensile strength, flexural strength, flexural modulus, etc. of the blend.

[0017]

EXAMPLES The method of the present invention will be specifically described below with reference to Reference Examples, Examples and Comparative Examples.

Reference Examples 1 to 3 [Synthesis Example of Styrene-based Polymer (A ')] 4,4'-azobis-4-cyanovaleric acid (ACVA) was used as a polymerization initiator, and styrene 10 was used.
0 parts by weight were radically polymerized at 90 ° C. ACVA is 1,
It was dissolved in 4-dioxane and added continuously during the polymerization as well as at the beginning of the polymerization. The concentrations of the ACVA added initially and the ACVA continuously added were changed, and the styrene-based polymer shown in Table 1 (Reference Example 1: A′-1, Reference Example 2:
A′-2 and Reference Example 3: A′-3) were obtained. The molecular weight is measured by Toyo Soda Co., Ltd. GPC measuring device HLC-8.
02A was used. The average number of carboxyl groups in one molecule of polymer is the automatic titrator G manufactured by Mitsubishi Kasei Co., Ltd.
It was measured by neutralizing titration of the polymer solution with a sodium hydroxide solution using T-05 type.

[0019]

[Table 1]

Reference Examples 4 to 6 [Synthesis of styrene-based polymer (A) having terminal amino group from styrene-based polymer (A ')] Styrene-based polymer (A'- synthesized in Reference Examples 1 to 3)
1, A′-2 or A′-3) 100 parts by weight is dissolved in dichloromethane, 3 to 7 parts by weight of p-xylenediamine is added, and 7 to 15 parts by weight of N, N ′ is added at room temperature under a nitrogen stream. −
Dicyclohexylcarbodiimide was added and amidated over about 4 hours to give a styrene-based polymer having an amino group at the end (Reference Example 4: A-1, Reference Example 5: A-2 and Reference Example 6: A-3). Synthesized. The number of terminal amino groups was determined by quantifying unreacted carboxyl groups in the same manner as in Reference Examples 1 to 3 above. The results are shown in Reference Example 4 (A-
1): 1.20, Reference Example 5 (A-2): 1.65 and Reference Example 6 (A-3): 1.80.

Examples 1 to 3 Styrene-based polymers synthesized in Reference Examples 4 to 6 in eggplant type flasks equipped with a stirrer (Example 1: A-1, Example 2: A-2)
Alternatively, Example 3: A-3) 100 parts by weight and 29 parts by weight of each of terephthalic acid dichloride and isophthalic acid dichloride are dissolved in 1,000 parts by weight of dichloromethane, and 0.1 part by weight of calcium hydroxide and 0 of triethylamine are used as a catalyst. 0.01 part by weight was added, and the mixture was reacted for 1 hour under stirring to convert the polystyrene terminal into an acid chloride. Then, 630 parts by weight of a 1N-sodium hydroxide aqueous solution was charged into another round bottom flask equipped with a stirrer, and bisphenol A was added.
The acid chloride solution prepared above was added to a solution prepared by dissolving 64 parts by weight and adding 0.05 parts by weight of trimethylbenzylammonium chloride as a catalyst. After the addition was completed, stirring was continued for 2 hours to carry out interfacial polymerization. After completion of the polymerization, the organic layer and the aqueous layer were separated, the organic layer was neutralized with 630 parts by weight of a 1N-acetic acid aqueous solution, and then washed with water, and only the organic layer was extracted to 1,000 parts by weight of chloroform. Dissolved. The chloroform solution was filtered using a 1 μm filter and then added to 10,000 parts by weight of methanol to precipitate a polymer. The obtained polymer precipitate was filtered, washed with methanol, and dried in a vacuum dryer.

The average molecular weight of the thus obtained polymer was measured in the same manner as in Reference Examples 1 to 3. In addition, it was confirmed that the obtained polymer was a copolymer by using 50 parts by weight of cyclohexane and using Polymer 1 for 26 hours.
Soxhlet extraction of parts by weight is performed to determine the weight ratio of the cyclohexane insoluble matter and the soluble matter (insoluble matter: soluble matter), and the composition of the cyclohexane insoluble matter is determined by ¹ H-NMR [JNM-JNM- EX40]. Only polystyrene that was not copolymerized is dissolved in cyclohexane. The polymerization results of Examples 1 to 3 are shown in Table 2.

The polymers obtained in Examples 1 to 3 were dissolved in methylene chloride to prepare a 20% by weight solution, which was prepared by Yasuda Seiki Co., Ltd.
Made of Automatic film applicat
or No. 1 on a glass plate using 542-AB-S
A film having a thickness of 00 μm was prepared. The film was left to stand at room temperature for 12 hours, and further dried in a vacuum dryer at 100 ° C. for 12 hours to remove the solvent. After removing the solvent, the obtained film was cooled to room temperature and left in water to be peeled off from the glass plate. No damage to the film was observed during this peeling, and a sample for stretching test with a size of 20 mm × 60 mm was obtained. The film thus obtained was stretched 10 to 50% at 215 to 220 ° C. using a hot air circulation type uniaxial stretching device manufactured by Satake Chemical Machinery Co., Ltd., and an optical-pol polarization microscope manufactured by Nikon Corporation was used. (Wavelength: 546 nm) was used to measure the birefringence of the film. The results are shown in Table 3.

Example 4 In a round bottom flask equipped with a stirrer, 100 parts by weight of the styrene polymer (A-3) synthesized in Reference Example 6 and 29 parts by weight of each of terephthalic acid dichloride and isophthalic acid dichloride were added to dichloromethane 1,000. It dissolved in parts by weight. Then, 630 parts by weight of 1N-sodium hydroxide aqueous solution was charged into another round bottom flask with a stirrer, 64 parts by weight of bisphenol A was dissolved, and 0.05 part by weight of trimethylbenzylammonium chloride as a catalyst was added to the solution. The acid chloride solution prepared above was added, and after the addition was completed, stirring was continued for 2 hours to carry out interfacial polymerization. After completion of the polymerization, the polymer was recovered in the same manner as in Examples 1 to 3,
The average molecular weight of the obtained polymer and the weight ratio of the cyclohexane insoluble matter and the soluble matter (insoluble matter: soluble matter) were measured. The results are shown in Table 2. Further, using the obtained polymer, a film was prepared and stretched in the same manner as in Examples 1 to 3 above, and the birefringence of the film was measured. The results are shown in Table 3.

Comparative Example 1 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-58-157,844. A solution of 203 g and 4.18 g of methacrylic acid chloride in methylene chloride and bisphenol A2
A polyester having a methacryl group at the end was produced from 33 g of an aqueous sodium hydroxide solution by an interfacial polymerization method. As a result of measuring the number average molecular weight Mn using GPC in the same manner as in the above Reference Example, it was 4,000. The polyester thus obtained and the styrene monomer were mixed in a weight ratio of 1: 1 while heating (130 ° C.) under a nitrogen atmosphere and polymerized for 20 hours. In the same manner as in Examples 1 to 3, the produced polymer was recovered, and its molecular weight, composition and polystyrene content not copolymerized were measured.
The results are shown in Table 2. With respect to the polymer obtained in Comparative Example 1, a film was formed in the same manner as in the above-mentioned Example, and after removing the solvent, it was left in water to be peeled off, but the film on the glass plate was broken to pieces and stretched. No test sample could be obtained.

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

[0027]

[Table 2]

[0028]

[Table 3]

From the results of the above Examples and Comparative Examples, the following matters were found. From the results of Examples 1 to 4, the wholly 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 1, according to the production method of the present invention, the amount of polystyrene not copolymerized can be reduced. From the comparison between Examples 1 to 4 and Comparative Example 2, the wholly aromatic polyester / polystyrene copolymer produced according to the present invention can reduce the birefringence even during stretching.

[0030]

EFFECTS OF THE INVENTION According to the present invention, the content of the styrene-based polymer which is not copolymerized is lower than that in the conventional polymerization method, and more than the conventional wholly aromatic polyester / polystyrene-based copolymer. All aromatic polyester with low birefringence
A polystyrene-based copolymer can be produced. Therefore, the wholly aromatic polyester / polystyrene copolymer produced according to the present invention can be used as a good material for optical equipment, and is added to a blend of the wholly aromatic polyester and the styrene polymer to form a phase mixture. It can also be used for the purpose of increasing the solubility and enhancing the tensile strength, flexural strength and flexural modulus of the blend.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification number Internal reference number FI Technical display location G11B 7/24 526 7215-5D (72) Inventor Masao Kimura 1618 Ida, Nakahara-ku, Kawasaki-shi, Kanagawa , Advanced Technology Research Laboratories, Nippon Steel Corporation (72) Inventor Koichi Fujishiro 1618 Ida, Nakahara-ku, Kawasaki City, Kanagawa Prefecture; Advanced Technology Research Laboratories, Nippon Steel Corporation (72) Inventor Shinji Inaba Kawasaki, Kanagawa Prefecture 1618 Ida, Nakahara-ku, Nippon Steel Corporation, Advanced Technology Research Laboratories (72) Inventor, Soichiro Kishimoto, 23 Uji Kozakura, Uji City, Kyoto Prefecture, Central Research Institute of Unitika Ltd. (72) Inventor, Takamasa Ohwaki Uji, Kyoto Prefecture 23, Uji Kozakura, City, Central Research Institute, Unitika Stock Company (72) Inventor Akio Motoyama 23, Uji Koza, Uji City, Kyoto Prefecture, Unitika Stock Company Central laboratory

Claims (1)

[Claims] 1. A styrene-based polymer (A) having an amino group at the terminal, an aromatic dihydroxy compound (B) and an aromatic dicarboxylic acid dihalide (C)
A method for producing a wholly aromatic polyester / polystyrene copolymer, which comprises performing interfacial polymerization at a ratio of [(B) + (C)] of 20/80 to 80/20 (weight ratio).