JPH04183724A - Production of wholly aromatic polyester-polystyrene-base copolymer - Google Patents

Abstract

PURPOSE:To obtain the subject copolymer, having a low birefringence, good in processability and useful as materials, etc., for optical instruments by subjecting a terminal amino group-containing styrene-based polymer with an aromatic dihydroxy compound and an aromatic dicarboxylic acid halide in a specific proportion to solution polycondensation. CONSTITUTION:Styrene is radical-polymerized using 4,4'-azobis-4-cyanovaleric acid as a polymerization initiator while being heated to provide a polymer having terminal carboxyl groups. The resultant polymer is subsequently reacted with 4,4'-diaminodiphenyl ether, etc., to afford (A) a styrene-based polymer having terminal amino groups. The obtained polymer (A) is then subjected to solution polycondensation with (C) an aromatic dihydroxy compound and (D) an aromatic dicarboxylic acid halide in amounts so as to provide (5/95)-(80/20) weight ratio of the components [(A)/(C+D)]. Thereby, the objective wholly aromatic polyester-polystyrene-based copolymer is obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a method for producing a wholly aromatic polyester/polystyrene copolymer.

[Conventional technology]

In general, wholly aromatic polyester resins, which have excellent transparency and are suitable for materials for optical devices, have excellent properties such as heat resistance and mechanical strength, but are difficult to process due to their high viscosity. In addition, stress distortion occurs during thermoforming processes such as injection molding, and the resulting product is prone to birefringence. As a result, when the final product is an optical disk or optical card protective film, birefringence causes reading errors and noise, and when the final product is an optical fiber, birefringence increases transmission loss and other problems. There are some points.

As a means to solve the above problems, a wholly aromatic polyester resin (hereinafter sometimes referred to as PAr) and a polystyrene resin having birefringence in opposite directions (hereinafter referred to as PS) are used.
(Sometimes referred to as
A method of adding Ar as a compatibilizer to an Ar blend system is known.

As a method for producing wholly aromatic polyester/polystyrene copolymers, there are methods disclosed in JP-A-58-157.844 and JP-A-58-225.113. However, in this production method, an unsaturated group is introduced at the end of a wholly aromatic polyester, and this is polymerized with a styrene monomer to form a wholly aromatic polyester/polystyrene copolymer. If the content of styrene-based polymer is too high, the mechanical strength of the product will decrease. As a result, a step is required to remove the remaining uncopolymerized styrene polymer, which is not suitable for industrial production. Furthermore, in Japanese Patent Application Laid-Open No. 1-129.011,
A styrenic monomer and allyl amino are mixed and polymerized, and this is mixed with a wholly aromatic polyester compound and a high temperature (260
~340°C) to melt and mix fully aromatic polyester.
Synthesizing polystyrene copolymers.

However, since washing with water cuts the polyester chains and copolymerizes the allylamino-modified styrenic polymer and the fully aromatic polyester, the chains of the fully aromatic polyester in the resulting polymer become shorter, resulting in insufficient strength. There is a problem in that it is difficult to obtain polymers with

[Problem to be solved by the invention]

The present invention aims to solve the above problems,
It is possible to reduce the content of uncopolymerized styrenic polymer in the produced polymer and to produce a wholly aromatic polyester/polystyrene copolymer with a long wholly aromatic polyester chain in the copolymer. The purpose is to provide a new manufacturing method.

[Means to solve the problem]

The present inventor has completed the following invention as a result of extensive research in order to achieve the above object.

That is, a wholly aromatic polyester/polystyrene copolymer is produced by solution condensation polymerization of a styrene polymer (A) having an amino group at the terminal, an aromatic dihydroxy compound (C), and an aromatic dicarboxylic acid halide (D). This is a method of manufacturing.

The present invention will be explained in detail below.

The styrenic polymer (A) used in the present invention may have one or more amino groups at the end or at the end and in the middle, but preferably has an amino group at one or both ends. More preferably, it has amino groups at both ends to increase reactivity.

The number average molecular weight W of this styrenic polymer (A) is 1,
000 or more and 200,000 or less.

If the number of eaves is less than 1,000, the physical properties of the polymer will be insufficient, and if the number of eaves exceeds 200,000, it will be difficult to synthesize the copolymer. Further, in the weight average molecular placement type, it is preferable that the ratio between W and the weight is 4.0 or less. If a copolymer is synthesized using a styrenic polymer with a W/melon ratio of more than 4.0, a copolymer with excellent molecular weight uniformity cannot be obtained, so it cannot be suitably used. In addition,
The adhesive and body measurements were performed using gel permeation chromatography (GPC) calibrated with monodisperse polystyrene (manufactured by Waters), using tetrahydrofuran as the mobile phase and an RI detector as the detector. 1. The measurement was performed at On//min.

Examples of styrenic monomers used to synthesize the styrenic polymer (A) are styrene, 0-1m-1
Alkylated styrenes such as p-methylstyrene, 0-1m-1p-ethylstyrene, p-tert-butylstyrene, 0-1m-1p-monochlorostyrene, dichlorostyrene, o-1m-1p-monobromostyrene, Examples include halogenated styrenes such as dipromostyrene, styrenic monomers such as α-methylstyrene, and mixtures thereof.

In addition, a small amount of vinyl polymerizable monomer other than the styrene thread binder may be added for the purpose of copolymerizing. As monomers for copolymerization, methacrylic esters, acrylic esters, acrylonitrile, maleic anhydride, ethylene, propylene, chloroethylene, butadiene, etc. can be used, and the amount used is 0 to 50% by weight based on the total amount of monomers. The content is desirably 0 to 20% by weight in order not to deteriorate the optical properties of the copolymer.

Examples of methods for synthesizing the styrenic polymer (A) used in the present invention include the following methods. First, a styrene monomer is radically polymerized using a polymerization initiator having a carboxyl group to synthesize a styrenic polymer (Ao) having a carboxyl group at the end.

This styrenic polymer (Ao) is obtained by amidation reaction with an excess of a diamino compound such as 4-4' diamino diphenyl ether in the presence of a suitable active catalyst and acid scavenger in a solution state in the presence of a solvent. Is there a method of radical polymerization using a polymerization initiator having an amino group (such as Wako Pure Chemical Industries Ltd. (VA-088))? Even if there is, it is only necessary to obtain a styrenic polymer having an amino group at the terminal.

Aromatic dihydroxy compound used in the present invention (
Examples of C) include bisphenol A, tetramethylbisphenol A1, tetrabromobisphenol A1, bis(4-hydroxyphenyl)-p-diisopropylbenzene, hydroquinone, resorcinol, 4,4'-dihydroxybiphenyl, etc. Among these, bisphenol A is preferred.

Examples of aromatic dicarboxylic acid halides (D) include compounds obtained by converting dicarboxylic acids into acid halides, such as isophthalic acid, terephthalic acid, nuclear halogen-substituted terephthalic acid, and inphthalic acid, and mixtures thereof.Among them, isophthalic acid dichloride and A mixture with terephthalic acid dichloride in a ratio of 5 to 75:25 parts by weight is preferred.

Is it possible to vary the proportions of the styrenic polymer (A), aromatic dihydroxy compound (C), and aromatic acid cyclocarphonic acid halide (0) over a wide range in order to obtain suitable optical properties and mechanical properties? It is necessary to adjust the content of the styrenic polymer to 5 to 80% by weight, and for this purpose, the weight of the styrenic polymer (A), the aromatic dihydroxy compound (C), and the aromatic acid dicarboxylic acid halide (D) must be adjusted to 5 to 80% by weight.
), i.e. (A)/F(C)-(D
) Set i within the range of 5/95 to 80/20. If the content of the styrenic polymer is less than 5%, the birefringence of the produced polymer cannot be sufficiently reduced. In addition, styrenic polymers (
When A) is increased to 80% or more, the rigidity of the resulting polymer decreases. Note that the ratio of the aromatic dihydroxy compound (C) and the aromatic acid dicarboxylic acid halide (D) is approximately equimolar, but since the styrene polymer (A) has an amino group, , it is preferable to use an excess of the aromatic dicarboxylic acid halide (D) in a molar amount equivalent to this.・The solution condensation polymerization method of the present invention involves the addition of the styrene polymer (A) and the aromatic dihydroxy compound (C) in an organic solvent.
) and an acid scavenger such as an alkali compound are dissolved, and an aromatic dicarboxylic acid halide dissolved in the same organic solvent is added thereto under stirring.

As an organic solvent, it does not react with the styrene polymer (A), the aromatic dihydroxy compound (C), or the aromatic dicarboxylic acid halide (D); Dicarboxylic acid halide (D) and the resulting wholly aromatic polyester
It is desirable that the solvent be a good solvent for any polystyrene copolymer.

Such organic solvents include, for example, halogenated hydrocarbons,
There are aromatic hydrocarbons, esters, ketones, etc., and specific examples include methylene chloride, chloroform, tetrachloroethane, chlorobenzene, dichlorobenzene, benzene, toluene, xylene, methyl ethyl ketone, ethyl acetate, dioxane, etc. can. Further, examples of the acid scavenger include sodium hydroxide, potassium hydroxide, calcium hydroxide, and the like. Solution polymerization reaction is carried out at 2-50°C1
Preferably, it is carried out at 5 to 50°C for about 5 minutes to 8 hours while stirring.

In the solution polymerization method of the present invention, in order to proceed smoothly with the polymerization reaction, tertiary amino acids such as triethylamino and trimethylamino, or quaternary ammonium salts such as trimethylbenzylammonium chloride and triethylbenzylammonium chlorite are added. You may. Further, in order to adjust the molecular weight, a monofunctional phenol compound such as 0-phenylphenol or p-tert-butylphenol can be added.

Various known methods can be employed to isolate and purify the produced polymer. For example, after the completion of polymerization, inorganic salts are filtered from the reaction solution, and if necessary, they are subjected to extraction or other cleaning operations, and then added to a solvent such as acetone or methanol to precipitate the polymer, which is then filtered and dried. , a method of isolating the desired polymer, etc. can be adopted.

In addition, when it is necessary to remove the styrene polymer that has not been copolymerized in the produced polymer, a solvent such as cyclohexane may be used to selectively dissolve and remove it.

The number average molecular weight of the resin synthesized according to the present invention is determined by GPC
The measured value is preferably 1,000 to 300,000. If it is less than 1,000, the physical properties of the polymer will be insufficient, and if it is more than 300,000, the resulting polymer will become gel-like, making it difficult to remove the solvent.

The wholly aromatic polyester/polystyrene copolymer synthesized in the present invention has good fluidity, high transparency, and is suitable for use alone as a material for optical equipment with low birefringence. , can be added to blends of fully aromatic polyesters and styrenic polymers to increase compatibility and can be used to enhance the tensile strength, flexural strength, and flexural modulus of the blends.

〔Example〕

Hereinafter, the present invention will be explained in more detail based on Reference Examples, Examples, and Comparative Examples.

Reference Examples 1-2 4.4″-azobis-4-cyanovaleric acid (
ACVA) was used as a polymerization initiator, and styrene was
Radical polymerization was carried out at ℃. ACVA was dissolved in a 1,4-dioxane solvent and added continuously at the beginning of the polymerization as well as during the polymerization. The obtained polymer was a styrene polymer (Ao) having a carboxyl group at the end, and its number average molecular weight (E), weight average molecular weight (weight), and number of carboxyl groups were measured. The results were as follows.

Reference example 1: Eaves = 15,000 Four = 33,000 Carboxyl groups = 2.01 pieces/1 molecule Reference example 2: [=30,000 pieces = 65,000 Carboxyl groups = 1.98 pieces, 71 molecules Counterfeits and defects were measured using gel permeation chromatography (calibrated with monodisperse polystyrene (Waters)).
GPC) using tetrahydrofuran as the mobile phase and an R+ detector as the detector, with an elution rate of 1.
．． 0i/m! Measurements were made at n. Moreover, the average number of carboxyl groups that one polymer molecule has was measured by neutralization titration with a sodium hydroxide solution.

Next, the method of S. Yasuda et al. (J. Polym
, Sci.

Polym, Chem, ED, 212609
(1983)), triphenylphosphine and hexachloroethane were used as active catalysts, and triethylamino was used as an acid acceptor.
Ao) was reacted with an excess of 4,4'-diaminodiphenyl ether to synthesize a styrenic polymer (A) having an amino group at the end. The obtained styrenic polymer (A
) was measured for li&, & and the number of amino groups. Result is,
It was as follows.

Reference Example 1: Road = 29,000 animals = 67,000 Amino groups = 1.89/1 molecule Reference Example 2: 1i = 53,000 Pregnancy = 110,000 Amino groups = 2.13/1 molecule The terminal amino group was measured by a known acetylation method.

Examples I to 2 In a glass flask equipped with a stirrer, a reflux condenser, a dropping funnel, and an N2 gas inlet, 20 parts by weight of bisphenol A and the styrenic polymer (A
) and 15 parts by weight of calcium hydroxide, 550 parts by weight of 1,2-dichloroethane was added and dissolved, and the mixture was further stirred at room temperature for 20 minutes while blowing N2 scum. Next, after adding 0.1 part by weight of triethylamino, the inside of the flask was maintained at 32°C, and acid halide in which 7.5% by weight each of terephthalic acid dichlorahide and isophthalic acid dichloride were dissolved (total 15% by weight) 150 parts by weight of a 1,2-dichloroethane solution of 12
Added over time. After the addition is complete, the inside of the flask is heated to 32°.
C. and polymerization was carried out under stirring for 4 hours.

After the polymerization was completed, the solution was filtered, and chloroform was added to the filtrate. The resulting solution was added to 3,000 parts by weight of methanol to precipitate the polymer, which was then filtered off. The precipitated polymer was degassed by drying in a vacuum dryer at a set pressure of 1 mmHg and a set temperature of 70° C. for 3 days.

Regarding the obtained recovered polymer, eaves, melon, and porosity/falseness were measured using the same GPC as used in Reference Examples 1 and 2. Further, to confirm the copolymer, 1 part by weight of the recovered polymer was subjected to Soxhlet extraction with 50 parts by weight of cyclohexane for 26 hours, and the composition of the cyclohexane-insoluble components was confirmed by NMR. Here, the polystyrene that has not been copolymerized is dissolved in cyclohexane. The results were as follows.

Example 1: Counterfeit = 35,000 animals = 140,000 animals/door = 3.98 Conversion rate = 98x Polymer composition PS: PAr = 53 + 47 unreacted P
S= 7 The recovered polymer was found to be a wholly aromatic polyester/polystyrene copolymer. Note that in Example 1, the styrenic polymer of Reference Example 1 (
This is an example using A), and Example 2 is an example using Reference Example 2.
This is an example using the styrenic polymer (A).

The polymers synthesized in Examples 1 and 2 above were dissolved in methylene chloride to prepare a 20% by weight solution, and a 100 mm thick film was prepared. The film was left at room temperature for 1.12 hours;
Further, the solvent was removed by drying in a vacuum dryer at 100° C. for 12 hours. The above film was stretched by 10 to 50% at 215 to 220° C. using a hot air circulation type axial stretching device, and the birefringence of the film was measured using a polarizing microscope (wavelength: 546 nm). The results are shown in Table 1.

Comparative Example 1 According to the example described in JP-A-58-157.844, a methylene chloride solution containing 203 g of mixed acid chloride with a molar ratio of terephthalic acid dichloride and isophthalic acid dichloride of 1=1 and 4.18 g of methacrylic acid chloride was prepared. and,
A polyester having methacrylic groups at the terminals was produced by an interfacial polymerization method using 233 g of bisphenol A in aqueous sodium hydroxide solution. As a result of measurement using the same GPC as the reference example, the number of fakes was 4,000.

This polyester and styrene monomer are mixed in a weight ratio of 1:l.
The mixture was mixed at a ratio of 1, and polymerized for 20 hours under heating (130°C) under a N2 atmosphere. The produced polymer was collected in the same manner as in Examples, and the molecular weight, composition, and content of non-copolymerized polystyrene of the polymer were evaluated in the same manner as in Examples 1 and 2 above.

The results were as follows.

Note = 7.500 animals = 2.200 animals/li! i"i=2.9 Cyclohexane extraction result: Insoluble content: Soluble content = 30 near 0
PS composition in copolymer = 25x Content of non-copolymerized PS = 70x Comparative Example 2 100 g of commercially available fully aromatic polyester (Unitika (manufactured by Kiki: U Polymer "U-100") was used) Then, the inherent viscosity, melt viscosity, and birefringence were measured in the same manner as in Examples 1 and 2. The results are shown in Table 1.

From the results of the Examples and Comparative Examples shown in Table 1, it can be concluded that: 1) the production method of the present invention can easily produce a fully aromatic polyester/polystyrene copolymer; 2) Comparison of each Example and Comparative Example 1. Therefore, according to the production method of the present invention, the amount of polystyrene that is not copolymerized can be reduced; (2) Comparison of Examples 1 to 2 and Comparative Example 2 shows that the fully aromatic polyester polystyrene synthesized according to the present invention; It has been found that the copolymer can reduce birefringence even under stretching compared to fully aromatic polyester.

〔Effect of the invention〕

According to the present invention, the amount of uncopolymerized styrene polymer is reduced compared to conventional polymerization methods, and the fully aromatic polyester/polystyrene polymer has lower birefringence than conventional wholly aromatic polyester. Polymers can be produced.

The wholly aromatic polyester/polystyrene copolymer produced according to the present invention can be used as a good optical device material, and can also be added to a blend of a wholly aromatic polyester and a styrene polymer to achieve compatibility. It can also be used to increase the tensile strength, flexural strength, and flexural modulus of blends.

Patent applicant: Nippon Steel Chemical Co., Ltd. Same as above Nippon Steel Corporation

Claims (1)

[Claims] A styrenic polymer (A) having an amino group at the end, an aromatic dihydroxy compound (C) and an aromatic dicarboxylic acid halide (D) are combined into (A)/[(C)+(D)]
A method for producing a wholly aromatic polyester/polystyrene copolymer, which comprises carrying out solution condensation polymerization at a weight ratio of 5/95 to 80/20.