JPS6241970B2 - - Google Patents

Description

Detailed Description of the Invention [Technical Field of the Invention] The present invention relates to a method for producing an aromatic polyester amide, and more specifically, it relates to a method for producing an aromatic polyester amide, and more particularly, it relates to a method for producing an aromatic polyester amide, and more specifically, a highly purified aromatic polyester amide without impairing heat resistance, mechanical strength, and moldability. The present invention relates to a method for producing polyesteramide. [Technical background of the invention and its problems] In recent years, with the progress of the polymer chemical industry, heat resistance,
Aromatic polyesteramides with excellent mechanical strength and electrical insulation properties have been developed, but
As a high-performance resin required in the electronic field,
The current situation is that it is not always possible to obtain something completely satisfactory. In order to obtain this high-performance resin, as a result of intensive research and development, the results were published in JP-A-57-108129, JP-A-57-108130, JP-A-56-157423, and JP-A-Sho. Publication No. 37739, Journal of Polymer Science: Polymer Chemistry Editions, Volume 20, Page 683, 1982 [Journal of Polymer Science: Polymer
Various methods have been proposed in Chemistry Edition, 20 , 683 (1982). In these proposals, the aromatic polyester amide is produced by applying a solution polymerization method or an interfacial polymerization method to terephthalic acid or isophthalic acid or a derivative thereof (A) and 2,2-(4'-hydroxy- A method for producing 4"-aminodiphenyl) propane or its derivatives (B) is disclosed. The solution polymerization method involves adding the above-mentioned raw materials (A) and (B) to a tertiary amine in a non-reactive organic solvent. In addition, the interfacial polymerization method involves reacting in the presence of an acid acceptor such as a non-reactive organic solvent solution containing the above-mentioned raw material (A) and an alkaline aqueous solution containing the above-mentioned raw material (B). Aromatic polyesteramides obtained by these manufacturing methods have good heat resistance (for example, glass transition temperature: 220°C or higher), but at the same time, the molding temperature is high, making it difficult to mold. Therefore, there has been a strong desire for a method for producing an aromatic polyester amide that has the above-mentioned various properties in a well-balanced manner.
When produced by the solution polymerization method, it contains tertiary amine hydrochloride as an impurity, which is produced as a by-product during the polymerization reaction, and when produced by the interfacial polymerization method, it contains a by-product during the polymerization reaction. It contains inorganic salts or dispersants used in polymerization reactions as impurities, and these impurities may cause accelerated separation or coloration of the resulting polymer during heat molding or heating. I was getting used to it. For this reason, the industry has desired the emergence of aromatic polyesteramides from which impurities have been sufficiently removed. [Object of the Invention] The object of the present invention is to eliminate the above-mentioned drawbacks, and to provide a method for producing highly purified aromatic polyester amide without impairing heat resistance, mechanical strength, electrical insulation, etc. It is in. [Summary of the Invention] The method for producing aromatic polyesteramide of the present invention has the following general formula: (In the formula, X represents a chlorine atom or a bromine atom)
An aromatic dicarboxylic acid dihalide represented by the general formula: (In the formula, R ₁ to _{R 4} may be the same or different, and each represents a hydrogen atom, a halogen atom, an alkyl group having 1 to 4 carbon atoms, a phenyl group, or a phenyl group having 1 to 4 carbon atoms. represents an alkoxy group of
Y represents a methylene group, an alkylidene group having 2 to 6 carbon atoms, an oxygen atom, a sulfur atom, a carbonyl group or a sulfonyl group, and n is 0 or 1) and an aromatic dihydroxy compound represented by the general formula: (In the formula, R ₅ to _{R 8} may be the same or different, and each represents a hydrogen atom, a halogen atom, an alkyl group having 1 to 4 carbon atoms, a phenyl group, or a phenyl group having 1 to 4 carbon atoms. (representing an alkoxy group) to produce an aromatic polyesteramide, a halogenated hydrocarbon solvent containing a crude aromatic polyesteramide and a ketone solvent and/or an ether solvent The method is characterized in that the organic mixed solvent solution consisting of is washed with water, and then the organic mixed solvent solution phase is separated from the aqueous phase, and the aromatic polyester amide is precipitated from the organic mixed solvent solution phase. Examples of the aromatic dicarboxylic acid dihalide (A) used in the present invention include isophthalic acid dichloride, terephthalic acid dichloride, isophthalic acid dibromide, terephthalic acid dibromide, etc.
At least one selected from the group consisting of these is used. Aromatic dihydroxy compound used in the present invention
Examples of (B) include hydroquinone, resorcinol,
4,4'-dihydroxyphenylmethane, 1,1-
Bis(4'-hydroxyphenyl)ethane, 2,2
-bis(4′-hydroxyphenyl)propane,
2,2-bis(4'-hydroxyphenyl)butane, 1,1-bis(4'-hydroxyphenyl)cyclohexane, 4,4-dihydroxydiphenyl ether, 4,4'-dihydroxydiphenyl sulfide , 4,4'-dihydroxydiphenyl ketone, 4,4'-dihydroxydiphenyl sulfone,
2,2-bis(3'-bromo-4'-hydroxyphenyl)propane, 2,2-bis(3'-methyl-
4'-hydroxyphenyl)propane, and at least one selected from the group consisting of these.
Seeds are used. Examples of the aromatic hydroxyamino compound (C) used in the present invention include 2,2-(4′-hydroxy-4″-aminodiphenyl)propane, 2,2-
(3′-methyl-4′-hydroxy-4″-aminodiphenyl)propane, 2,2-(4′-hydroxy-
3″-methyl-4″-aminodiphenyl)propane,
2,2-(3′-chloro-4′-hydroxy-4″-aminodiphenyl)propane, 2,2-(4′-hydroxy-3″-chloro-4″-aminodiphenyl)propane, 2,2-(3 '-Bromo-4'-hydroxy-4''-aminodiphenyl)propane, 2,2-
(4′-hydroxy-3″-bromo-4″-aminodiphenyl)propane, 2,2-(4′-hydroxy-
3″-phenyl-4″-aminodiphenyl)propane, 2,2-(4′-hydroxy-3″-methoxy-
4″-aminodiphenyl)propane, 2,2-
(3′-bromo-4′-hydroxy-3″-bromo-
4″-aminodiphenyl)propane, etc.
At least one selected from the group consisting of these is used. The organic mixed solvent used in the present invention consists of a halogenated hydrocarbon solvent and a ketone solvent and/or an ether solvent. Examples of the halogenated hydrocarbon solvent include methylene chloride, chloroform, carbon tetrachloride, dichloroethane, trichloroethane, tetrachloroethane, dichloroethylene, trichloroethylene, tetrachloroethylene, and various chlorinated compounds having 3 or more carbon atoms. Examples of ketone solvents include acetone, methyl ethyl ketone, cyclohexanone,
Examples include acetophenone. Examples of ether solvents include tetrahydrofuran, 1,4-
Examples include dioxane. At least one type of these solvents selected from each group is used, and a mixture of each solvent is also used. Mixed systems of these solvents include methylene chloride and cyclohexanone, chloroform and cyclohexanone, dichloroethane and cyclohexanone, methylene chloride and tetrahydrofuran, chloroform and tetrahydrofuran, dichloroethane and tetrahydrofuran, methylene chloride and 1,4-dioxane, and chloroform and 1,4-dioxane. dioxane,
Dichloroethane and 1,4-dioxane, methylene chloride and cyclohexanone and tetrahydrofuran, methylene chloride and cyclohexanone and 1,4
-Dioxane, methylene chloride and acetone and tetrahydrofuran, methylene chloride and acetone and 1,4-dioxane, chloroform and cyclohexanone and tetrahydrofuran, chloroform and cyclohexanone and 1,4-dioxane, chloroform and acetone and tetrahydrofuran, chloroform and acetone and 1,4 - Examples include dioxane. The manufacturing method of the present invention can be implemented in various ways. That is, for example, (1) a method of carrying out a polycondensation reaction in a homogeneous solution in the presence of a halogenated hydrocarbon solvent and a tertiary amine using an aromatic dicarboxylic acid dihalide as a starting material; (2) a method of carrying out a polycondensation reaction as a starting material; Using an aromatic dicarboxylic acid dihalide, a halogenated hydrocarbon solvent and optionally a third catalyst as a catalyst.
Examples include a method of carrying out a polycondensation reaction in a heterogeneous solution in the presence of an aqueous solution of a basic compound to which a class amine is added. The mixing ratio of the reaction raw materials in the present invention is as follows: aromatic dihydroxy compound (B) and aromatic hydroxyamino compound to aromatic dicarboxylic acid dihalide (A).
The total amount of (C) is in a molar ratio of 0.9 to 1.1, preferably 0.95 to 1.05. If the blending ratio of these compounds is out of the above-mentioned range, it will be difficult to obtain a high enough polymer to exhibit good mechanical strength, which is not preferable. The molar ratio of compound (C) to compound (B) is in the range of 0.1 to 10, preferably in the range of 0.2 to 5. If the blending ratio of compound (C) to compound B is less than 0.1,
The heat resistance of the polymer is poor, and if the number is more than 10, the heat resistance will improve, but the softening temperature will become high and the moldability will be poor, which is not preferable. The polymerization reaction in the present invention involves reacting an aromatic dicarboxylic acid dihalide with an aromatic dihydroxy compound and an aromatic hydroxyamino compound. The reaction conditions at this time are preferably in an inert atmosphere such as nitrogen, under stirring, usually at -20 to 50°C, preferably 0 to 30°C, for usually 0.1 to 20 hours, preferably 1 to 30°C.
It is 10 hours. In the present invention, the organic solvent solution containing aromatic polyesteramide refers to the above-mentioned polymerization reaction finished liquid itself, a solution obtained by mixing the polymerization reaction finished liquid with another organic solvent, and a solution after the aromatic polyesteramide is once separated from the polymerization reaction finished liquid. , means a solution etc. that are redissolved in an organic mixed solvent solution. That is, the organic mixed solvent consisting of a halogenated hydrocarbon solvent, a ketone solvent, and an ether solvent means that each solvent is used at an appropriate time during the entire reaction process. For example, a halogenated hydrocarbon solvent may be used as the reaction solvent, and the halogenated hydrocarbon solvent and the ketone solvent may be added to the reaction mixture after the reaction is completed. In addition, this organic mixed solvent solution does not need to be completely homogeneous; for example, when a solution polymerization method is adopted, hydrochloride of a by-produced tertiary amine may be mixed in insoluble form. When an interfacial polymerization method is adopted, a small amount of the aqueous phase may be present, or depending on the type of solvent and other conditions, a small amount of the polymer may be present in an expanded state. The blending ratio of the halogenated hydrocarbon solvent and the ketone solvent and/or ether solvent in the organic mixed solvent used in the present invention is usually 95:
Range of 5-30:70%, preferably 90:10-50:50
% range. If the blending ratio of the ketone solvent and/or ether solvent is less than 5%, the cleaning effect will be insufficient, and the ratio of the halogenated hydrocarbon solvent will increase.
If it is less than 30%, separation of the organic solvent solution phase and aqueous phase during washing with water may become insufficient, and in some cases, a portion of the polymer product may precipitate, which is not preferable.
Further, the mixing ratio of the ketone solvent and the ether solvent is arbitrary. The concentration of aromatic polyester amide in the organic solvent solution of the present invention is usually in the range of 1 to 40% by weight, preferably in the range of 5 to 30% by weight. If this concentration is less than 1% by weight, the amount of solvent used will be large, which is not economically advantageous; if it exceeds 40% by weight, the cleaning effect will be reduced due to high solution viscosity, and
It becomes difficult to separate the organic solvent solution phase and the aqueous phase. The water washing step in the production method of the present invention is a step of washing the produced organic solvent solution containing the aromatic polyesteramide with water. The temperature in this water washing step is usually below the boiling point of the organic solvent, preferably around room temperature, and the pressure is usually normal pressure. Also,
The amount of water used and the number of times of water washing are usually in the range of 10 to 500%, preferably 50 to 300% by weight, based on the organic solvent solution per cleaning operation.
%, and the number of washings is not particularly limited, but is preferably from 1 to 5 times in view of economical efficiency. After the washing treatment in the production method of the present invention, simply allowing the treatment solution to stand still separates the organic mixed solvent solution phase and the aqueous phase, so that both phases can be easily separated.
Then, the separated organic mixed solvent solution phase may be treated with a sufficient amount of a poor solvent to precipitate the polymer. Examples of this poor solvent include methanol, ethanol, and the like. This precipitate is filtered and dried to obtain aromatic polyesteramide. [Effects of the Invention] As detailed above, the aromatic polyester amide according to the production method of the present invention is highly refined, so it is difficult to use ordinary molding methods such as compression molding, extrusion molding, and injection molding. Moreover, good molded products without discoloration, cracks, crazes, etc. due to molding processing can be obtained. At the same time, it has excellent heat resistance, mechanical strength, electrical insulation, etc., less coloring when used at high temperatures, and extremely good mechanical strength retention properties, so it has great industrial value as a heat-resistant resin. It is. EXAMPLES Below, the present invention will be explained in more detail by presenting Examples and Comparative Examples. [Examples of the Invention] Note that the logarithmic viscosity ηinh shown in the examples was determined using the following formula by measuring a solution with a concentration of 0.5 g/dl using an Ubbelohde viscometer at 30°C using cyclohexanone as a solvent. It is something. ηinh=In(t/to)/c [where t is the flow time of the polymer solution, to is the flow time of only the solvent, and c is the concentration of the polymer (unit:
g/dl). ] In addition, all parts and ratios in the examples are based on weight. The polymerization reaction was carried out under a nitrogen atmosphere. The bending strength and bending elastic modulus of the molded product are
Measured according to ASTM D-790 method. Example 1 56.23 parts of 2,2-bis(4'-hydroxyphenyl)propane and 2,2-(4'-hydroxy-4''-
1000 parts of methylene chloride and 105 parts of triethylamine were added to 56.00 parts of (aminodiphenyl)propane and stirred to form a solution. A solution of 50.10 parts of isophthalic acid dichloride and 49.92 parts of terephthalic acid dichloride dissolved in 250 parts of methylene chloride was added dropwise to this solution over 30 minutes while stirring while maintaining the temperature at 15 to 20°C, and then at 20 to 25°C for another 10 hours. Stirring was performed. 1000 parts of methylene chloride and 900 parts of cyclohexanone were added to the obtained reaction solution to obtain a uniform mixed solvent solution. After adding 2,000 parts of water to this mixed solvent solution and washing with vigorous stirring, the layers were separated, and the organic mixed solvent solution phase was washed in the same manner four times with 2,000 parts of water each. The washed organic mixed solvent solution was added to 15,000 parts of methanol under vigorous stirring to precipitate a polymer. The polymer was filtered and dried to obtain 168 parts of powdered polymer (yield: 95%). The logarithmic viscosity of the obtained polymer was 1.27 dl/g. The infrared absorption spectrum of the polymer film has an absorption band based on amide groups at 3340 cm ^-1 (ν _NH )
An absorption band based on the ester group was observed at 1740 ^{cm -1 (} ν _{C=O )} . This polymer is molded using a pressure molding machine at a temperature of 280℃ and a pressure of 200℃.
Compression molded at Kg/ ^cm2 , diameter 100mm, thickness 0.5~6mm
We prototyped a disk. The obtained prototype board was pale yellow and transparent, with no cracks or crazes. In addition, molded products made from this polymer were strong and had excellent heat resistance. Examples of physical properties of molded products include bending strength of 11.5Kg/mm ² , bending elastic modulus of 240Kg/mm ² ,
The glass transition temperature determined by differential scanning calorimetry (DSC) was 228°C. Example 2 45.25 parts of 2,2-bis(4'-hydroxyphenyl)propane and 2,2-(4'-hydroxy-4''-
1.001 to 45.00 parts of aminodiphenyl propane and 0.50 parts of trimethylbenzylammonium chloride
803.4 parts of a specified aqueous sodium hydroxide solution was added and dissolved, and the mixture was maintained at 10°C. A solution prepared by dissolving 40.15 parts of isophthalic acid dichloride and 40.27 parts of terephthalic acid dichloride in 1500 parts of methylene chloride was immediately poured into the above aqueous solution which was kept at 10°C and stirred vigorously, and stirred for 1 hour while maintaining the temperature at 10 to 15°C. I went there. Next, 13 parts of 1N hydrochloric acid was added, and then 800 parts of cyclohexanone and 1000 parts of water were added for washing and separation, and the organic mixed solvent solution was further washed twice with 2000 parts of water each. The washed organic mixed solvent solution was added to 10,000 parts of methanol with vigorous stirring to precipitate a polymer. The polymer was filtered and dried to obtain 133 parts of powdered polymer (yield: 94%). The logarithmic viscosity of the obtained polymer was 0.74 dl/g, and the sheets and plates obtained by compression molding in the same manner as in Example 1 were pale yellow, transparent, and strong without cracks or crazes. Example 3 57.32 parts of 2,2-bis(4'-hydroxyphenyl)propane and 2,2-(4'-hydroxy-4''-
1000 parts of tetrahydrofuran and 106 parts of triethylamine were added to 55.98 parts of aminodiphenyl)propane and stirred to form a solution. While stirring and keeping this solution at 15-20℃, add isophthalic acid dichloride.
A solution prepared by dissolving 50.71 parts of terephthalic acid dichloride and 50.26 parts of tetrahydrofuran in 250 parts of tetrahydrofuran was added dropwise over 30 minutes, and the mixture was further stirred at 20 to 25°C for 15 hours. Add tetrahydrofuran to the resulting reaction solution.
After adding 1,500 parts, triethylamine hydrochloride, which was produced as a by-product and precipitated during the polymerization reaction, was filtered off to obtain a homogeneous tetrahydrofuran solution. This solution was added to 12,000 parts of methanol with vigorous stirring to precipitate a polymer. The polymer was filtered and dried to obtain 172 parts of crude polymer powder (yield: 97%). The logarithmic viscosity of the crude polymer was 1.06 dl/g. 90 parts of the obtained crude polymer powder was dissolved in chloroform.
It was dissolved in a mixed solvent of 800 parts of tetrahydrofuran and 200 parts of tetrahydrofuran, washed with 1000 parts of water, separated, and the same operation was repeated once again. The washed organic mixed solvent solution was added to 6000 parts of methanol to precipitate the polymer, which was filtered and dried to obtain 86 parts of purified polymer powder. The logarithmic viscosity of the purified polymer was 1.09 dl/g. Sheets and plates obtained by compression molding this purified polymer in the same manner as in Example 1 were pale yellow, transparent, and strong, with no cracks or crazes. Example 4 67.60 parts of 2,2-bis(4′-hydroxyphenyl)propane, 2,2-(4′-hydroxy-4″-
44.88 parts of aminodiphenyl)propane, 51.11 parts of isophthalic acid dichloride, and 49.10 parts of terephthalic acid dichloride were reacted in the same manner as in Example 1 in 1250 parts of chloroform using 102 parts of triethylamine as an acid acceptor. To the obtained reaction solution, 1000 parts of chloroform and 500 parts of 1,4-dioxane were added to make a mixed solution, and then 2000 parts of water was added to each solution to give 500 parts of 1,4-dioxane.
Washed twice. The separated organic mixed solvent solution was added to 18,000 parts of methanol to precipitate the polymer, which was filtered and dried to yield 170 parts of powdered polymer (yield: 96%).
I got it. The logarithmic viscosity of the resulting polymer was 1.35 dl/g, and the sheets and plates obtained by compression molding in the same manner as in Example 1 were pale yellow, transparent, and strong without cracks or crazes. Example 5 61.76 parts of 2,2-bis(4′-hydroxyphenyl)propane, 2,2-(4′-hydroxy-4″-
50.32 parts of aminodiphenyl)propane, 54.93 parts of isophthalic acid dichloride, and 44.94 parts of terephthalic acid dichloride were reacted in the same manner as in Example 1, using 105 parts of triethylamine as an acid acceptor in 1,250 parts of 1,4-dioxane. The obtained reaction solution was filtered to remove triethylamine hydrochloride which was produced as a by-product during the reaction and precipitated, and then 2000 parts of methylene chloride was added to prepare a mixed solvent solution. 2000 parts of water was added to this mixed solvent solution for washing and separation. The mixed solvent solution was added to 15,000 parts of methanol to precipitate the polymer, which was filtered and dried to obtain 169 parts of powdered polymer (yield: 96%). The logarithmic viscosity of the obtained polymer was 1.00 dl/g, and the sheets and plates obtained by compression molding in the same manner as in Example 1 were pale yellow, transparent, and strong without cracks or crazes. Comparative Example 1 44.77 parts of 2,2-bis(4'-hydroxyphenyl)propane, 2,2-(4'-hydroxy-4''-
68.58 parts of aminodiphenyl)propane, 50.69 parts of isophthalic acid dichloride, and 50.29 parts of terephthalic acid dichloride were reacted in the same manner as in Example 1 in 1250 parts of methylene chloride using 106 parts of triethylamine as an acid acceptor. After diluting the resulting reaction solution by adding 2000 parts of methylene chloride, 2000 parts of water was added for washing and separation, and the same operation was repeated 5 times. The methylene chloride solution after washing is dissolved in methanol.
The polymer was added to 15,000 parts to precipitate the polymer. The polymer was filtered and dried to obtain 173 parts of powdered polymer (yield: 97%). The logarithmic viscosity of the obtained polymer was 1.19 dl/g. This polymer was compression molded in the same manner as in Example 1 to produce sheets and plates. The obtained sheets and plates were colored pale yellowish brown and transparent. However, some of the prototype plates were mechanically weak, and some of them developed cracks during molding and were not good molded products. Among these, the bending strength of relatively good molded products varied widely, ranging from 4.3 to 10.1 Kg/mm ² , and some of them lacked toughness. Comparative Example 2 45.40 parts of 2,2-bis(4′-hydroxyphenyl)propane, 2,2-(4′-hydroxy-4″-
44.50 parts of aminodiphenyl)propane and 0.50 parts of trimethylbenzylammonium chloride to 1.001 parts
An aqueous solution dissolved in 804.3 parts of the specified aqueous sodium hydroxide solution, 40.38 parts of isophthalic acid dichloride, and 39.74 parts of terephthalic acid dichloride were mixed with methylene chloride.
A solution of 1,500 parts was mixed and reacted in the same manner as in Example 2. Next, 18 parts of 1N hydrochloric acid were added, and then 1000 parts of water were added to wash and separate the layers, followed by washing twice with 2000 parts of water each. The methylene chloride solution after washing was added to 10,000 parts of methanol to precipitate the polymer. The polymer was filtered and dried to obtain 134 parts of powdered polymer (yield: 95%). The logarithmic viscosity of the obtained polymer was 0.70 dl/g. This polymer was compression molded in the same manner as in Example 1 to produce sheets and plates. The obtained sheets and plates were transparent but colored brown. The molded product was mechanically strong. Comparative Example 3 The crude polymer obtained in Example 3 was compression molded in the same manner as in Example 1 to fabricate sheets and plates. The obtained sheets and plates were transparent but colored yellow. The molded product was mechanically strong. Examples 6 to 10 The plates with a thickness of 2 to 4 mm prepared in Examples 1 to 5 were
After heating at 200°C in air for 10 days, the appearance and bending strength were examined. Each test plate was colored pale yellow, but no change in shape was observed. It was also mechanically strong, with no change observed in bending strength. The results are shown in the table. Comparative Examples 4 and 5 The 2-4 mm thick plates prepared in Comparative Examples 2 and 3 were tested in the same manner as Examples 6-10. Although no change in shape was observed, the degree of coloring was greater than in Examples 6 to 10, and the bending strength was slightly lower than the initial value. The results are shown in the table. 【table】

Claims (1)

[Claims] 1. General formula: (In the formula, X represents a chlorine atom or a bromine atom)
An aromatic dicarboxylic acid dihalide represented by the general formula: (In the formula, R ₁ to _{R 4} may be the same or different, and each represents a hydrogen atom, a halogen atom, an alkyl group having 1 to 4 carbon atoms, a phenyl group, or a phenyl group having 1 to 4 carbon atoms. represents an alkoxy group of
Y represents a methylene group, an alkylidene group having 2 to 6 carbon atoms, an oxygen atom, a sulfur atom, a carbonyl group, or a sulfonyl group, and n is 0 or 1) and an aromatic dihydroxy compound represented by the general formula: (In the formula, R ₅ to _{R 8} may be the same or different, and each represents a hydrogen atom, a halogen atom, an alkyl group having 1 to 4 carbon atoms, a phenyl group, or a phenyl group having 1 to 4 carbon atoms. (representing an alkoxy group) to produce an aromatic polyesteramide, a halogenated hydrocarbon solvent containing a crude aromatic polyesteramide and a ketone solvent and/or an ether solvent The production of an aromatic polyester amide is characterized by washing an organic mixed solvent solution consisting of the following with water, then separating the organic mixed solvent solution phase from the aqueous phase to precipitate the aromatic polyester amide from the organic mixed solvent solution phase. Method.