JPH0449571B2 - - Google Patents

Description

[Detailed description of the invention]

INDUSTRIAL APPLICATION FIELD OF THE INVENTION The present invention relates to the production of aromatic polyamide copolymers with high regularity. More specifically, an aromatic polyamide copolymer is produced in which two different aromatic diamine units and one or two aromatic dicarboxylic acid units are alternately and regularly arranged in the molecular chain. It is about the method. Prior Art Aromatic polyamides obtained from aromatic diamines and aromatic dicarboxylic acids have high melting temperatures, high thermal decomposition temperatures, and high glass transition temperatures, and have excellent heat resistance and
It is known to provide molded products with excellent chemical resistance and other chemical and physical properties. Fibers made of aromatic polyamides and having excellent thermal properties (for example, polymetaphenylene fistalamide fibers) are useful as heat-resistant and flame-retardant fibers for protective clothing, filter bags, and the like. In addition, fibers made of aromatic polyamides and having excellent mechanical properties such as a large initial Young's modulus and strength (for example, polyparaphenylene terephthalamide fibers) are used as rubber reinforcing materials for tire cords, belts, hoses, etc., and as plastics for composite materials. Useful for reinforcement materials, ropes, bulletproof clothing, etc. Also, certain copolymerized aromatic polyamides are useful as well. In particular, the copolymerized aromatic polyamide retains the excellent properties of aromatic polyamide,
It also has the advantage of improving solubility and moldability. (For example, see Japanese Patent Publication No. 53-32838.) Incidentally, the aromatic polyamide copolymer is obtained by polymerizing two or more kinds of aromatic diamine components and/or two or more kinds of aromatic dicarboxylic acid components. However, in these copolymers, for example, when there is one type of acid component and two types of diamine components, normal polymerization methods cannot be used completely due to the difference in reactivity of the two diamines and the randomness of the reaction. Alternating copolymers are not obtained, but random or block copolymers and copolymers with polymer sequences intermediate between these are obtained. (Peter A.Curnuck and Michael E.B.
Jones “A Atudy of Sequence Distribution in
An Aromatic Copolyamide, Br.Polym.J 1973, 5.21-32) The same applies to the reverse case, that is, when there are two acid components and one diamine component.
Random copolymers, block copolymers, and copolymers with intermediate polymer sequences have better moldability such as solubility than homopolymers, but their thermal properties are significantly lower than homopolymers. crystallinity may deteriorate. There is a need for a copolymer that has improved these drawbacks, that is, an aromatic polyamide copolymer that has excellent moldability such as solubility, and improved thermal properties and crystallinity. For this purpose, an alternating copolymer or a copolymer similar to the alternating copolymer having a highly regular polymer sequence is expected. The following method can be considered as a method for synthesizing such a highly regular aromatic polyamide copolymer. (b) Two acid components (HOOC-T-COOH,
HOOC-S-COOH) and the diamine component is one component (H ₂ N-A-NH ₂ ) H ₂ N-A-NHCO-T-CONH-A-NH ₂
+ClCO-S-COCl→(-NH-A-NHCO-T
-CONH-A-NHCO-S-CO-) _o (B) One acid component (HOOC-T-COOH) and two diamine components (H ₂ N-A-NH ₂ ,
H ₂ N−B−NH ₂ ) ClCO−T−CONH−A−NHCO−T−
COCl＋H ₂ N−B−NH ₂ →(−CO−T−CONH
-A-NHCO-T-CONH-B-NH- ₎ oHowever, in these methods H ₂ N-A-NHCO
-T-CONH-A- _NH2 , ClCO-T-CONH-
Since the synthesis and purification of the compound A-NHCO-T-COCl is difficult and does not result in high purity, a copolymer with a high degree of polymerization that can be processed into molded products such as fibers cannot be obtained. Purpose of the Invention The purpose of the present invention is to
An object of the present invention is to provide a method for industrially producing an aromatic polyamide copolymer in which aromatic diamine residues and one or two aromatic dicarboxylic acid residues are alternately and regularly arranged. . Structure of the Invention The present invention is based on the general formula (A) H ₂ N-Ar ₂ -NHCO-Ar ₁ -CONH-Ar ₃ -NH ₂ ...(A) [wherein Ar ₁ is a paraphenylene group and Ar ₂ is a paraphenylene group] group or metaphenylene group, Ar ₃ is

[expression] or

Represents [formula]. (X represents -O-, _-SO2- , _-CH2- )];
General formula (B) ClCO- _Ar4 -COCl...(B) [ _Ar4 represents a paraphenylene group or a metaphenylene group. ] This is a method for producing an aromatic copolymer having high regularity, which is characterized by reacting an aromatic dicarboxylic acid chloride represented by the following. In the aromatic diamino compounds and aromatic dicarboxylic acid chlorides represented by the general formulas (A) and (B) used in the present invention, Ar ₁ represents a paraphenylene group, and the hydrogen atom of the aromatic ring of this aromatic residue is It may be substituted with a substituent such as a phlogen group, an alkyl group having 1 to 10 carbon atoms, an alkoxy group, an acetyl group, or a benzoyl group. Ar ₂ represents a paraphenylene group or a metaphenylene group, preferably a paraphenylene group.
The hydrogen atom of the aromatic ring of this aromatic residue is a halogen group, an alkyl group having 1 to 10 carbon atoms, an alkoxy group,
It may be substituted with a substituent such as an acetyl group or a benzoyl group. Preferred examples of Ar ₃ include:

【formula】

【formula】

【formula】

【formula】

【formula】

【formula】 Among them, the more preferable ones are:

【formula】

[Formula], which is the most preferable The thing is

[Formula]. The hydrogen atom of the aromatic ring of this aromatic residue may be substituted with a substituent such as a halogen group, an alkyl group having 1 to 10 carbon atoms, an alkoxy group, an acetyl group, or a benzoyl group. Ar ₄ represents a paraphenylene group or a metaphenylene group, preferably a paraphenylene group. The hydrogen atom of the aromatic ring of this aromatic residue may be substituted with a substituent such as a halogen group, an alkyl group having 1 to 10 carbon atoms, an alkoxy group, an acetyl group, or a benzoyl group. In the present invention, it is preferable to use one type each of the above-mentioned aromatic diamine and aromatic dicarboxylic acid chloride, but two or more types can also be used if necessary. For example, as an aromatic diamine As aromatic dicarboxylic acid chloride When reacting with or, etc., and some of the aromatic dicarboxylic acids may be replaced with You can also replace it with According to the present invention, the polymerization method of reacting the asymmetric aromatic diamino compound represented by the general formula (A) with the aromatic dicarboxylic acid chloride represented by the general formula (B) includes a method for polymerizing an aromatic polyamide. Although various methods used in the above can be applied, since the asymmetric aromatic diamine compound represented by the general formula (A) is poorly soluble, a low-temperature solution polymerization method using an aprotic amide solvent that dissolves the asymmetric aromatic diamine compound is preferred. Examples of such aprotic amide solvents include dimethylformamide (DMF), dimethylacetamide (DMAC), N-methyl-2-pyrrolidone (NMP), tetramethylurea (TMU), and hexamethylphosphoramide (HMPA). It will be done. Among these, NMP and DMAC are particularly preferred. The reaction temperature is selected depending on the concentration of monomer or polymer, but is preferably in the range of 0°C to 100°C. It is also possible to isolate and use the polymer by mixing the polymer solution obtained by low-temperature solution polymerization with water, separating the precipitated polymer, washing it with water, and drying it, but in general, the obtained polymer The solution is directly subjected to shaping such as spinning or film formation. In that case, the hydrochloric acid replicated by polymerization is mixed with an alkali or alkaline earth metal oxide, hydroxide, carbonate, such as lithium oxide, lithium hydroxide, lithium carbonate, calcium oxide, calcium hydroxide, calcium carbonate, etc. It is preferable to neutralize it. The asymmetric aromatic diamino compound of the general formula (A) used in the method of the present invention can be prepared by the method separately proposed by the present inventors, that is, the general formula ClCO−Ar ₁ −COCl [where Ar ₁ is the same as above] ] and a compound represented by the general formula O ₂ N-Ar ₂ -NH ₂ [wherein Ar ₂ is the same as above] in an aprotic amide solvent at 0° C. or lower, and then Without separating the product, it is then reacted with a compound represented by the general formula O ₂ N-Ar ₃ -NH ₂ [wherein Ar ₃ is the same as above] to form the general formula O ₂ N-Ar ₂ -NHCO. -Ar ₁ -CONH-Ar ₃ -NO ₂ [In the formula, Ar ₁ , Ar ₂ and Ar ₃ are the same as above] An asymmetric aromatic dinitro compound represented by the following is prepared, and then it is produced by a method of catalytic reduction. be able to. Since this compound is stable and can be easily purified to high purity by recrystallization, the method of the present invention can be used to produce an aromatic polyamide with a high degree of polymerization (intrinsic viscosity [IV] of 1 to 5) and high regularity. A copolymer can be obtained. The obtained copolymer can be easily molded into molded products such as fibers and films. Furthermore, the aromatic polyamide copolymers with high regularity obtained by the method of the present invention are not limited to random copolymers or block copolymers obtained by conventional methods, and copolymers having polymer sequences intermediate thereto. It has the advantage of maintaining excellent solubility and excellent crystallinity compared to coalescence. Examples Comparative examples and examples of the present invention will be described in detail below.
In addition, the intrinsic viscosity (IV) of the polymer in this specification
The value is 0.5 for polymer concentration in 98% concentrated sulfuric acid.
This is a value measured at 30°C for a solution of g/dl. Comparative Example 1 560 ml of N-methyl-2-pyrrolidone (NMP) was put into a flask with an anchor-shaped stirring blade through which nitrogen was flowing, and 8.76 g of paraphenylenediamine and 3,4'-diaminodiphenyl ether were added.
16.224g was dissolved. The temperature of this solution is 30℃
At this time, 32.750 g of terephthalic acid chloride was added, and vigorous stirring was continued. The viscosity of the solution gradually increased, and after 15 minutes the temperature of the solution was heated to 85°C, a slurry consisting of 11.952 g of calcium hydroxide and 40 ml of NMP was added, and stirring was continued at 90°C. Stirring and heating were completed after 60 minutes, a portion of the sample was sampled and mixed with water, and the resulting polymer precipitate was washed with water, dried, and the intrinsic viscosity (IV) was measured. The IV of the polymer was 2.45. When this polymer was measured using a differential scanning calorimeter, no obvious crystallization behavior was observed.
Two melting pyrolysis peaks were observed at 495°C and 521°C. After the NMP solution of the polymer thus obtained is filtered and degassed, it is passed through a nozzle with a hole diameter of 0.2 mm and 5 holes by a so-called semi-dry semi-wet spinning method into an aqueous coagulation bath containing 30 wt% of NMP at room temperature. The material was spun at a discharge speed of 5 m/min and wound up at a speed of 6 m/min. Next, the threads, which were washed with water and dried in a conventional manner, were drawn on a hot plate at the temperatures shown in Table 1. Table 1 shows the maximum draw ratio (MDR) at which the fiber breaks at each temperature and the strength, elongation, and initial Young's modulus of the fiber obtained by drawing at a draw ratio of 80% of the MDR.

[Table] Example 1 560 ml of N-methyl-2-pyrrolidone (NMP) was charged into a flask equipped with an anchor-shaped stirring blade through which nitrogen was flowing, and 30.029 g of the following compound was dissolved therein. When the temperature of this solution was 30° C., 13.843 g of terephthalic acid chloride was added and vigorous stirring was continued.
The viscosity of the solution was slowly increasing. Calcium hydroxide was added after 15 minutes after heating the solution to 85℃.
A slurry consisting of 5.052 g and 40 ml of NMP was added and stirring continued at 90°C. Stirring and heating were completed after 60 minutes, a portion of it was sampled and mixed with water.
The obtained polymer precipitate was washed with water, dried, and the intrinsic viscosity (IV) was measured. The IV of the polymer is 2.52
It was hot. When this polymer was measured using a differential scanning calorimeter, a crystallization region existed between 400 and 450°C, and one melting thermal decomposition peak was observed at 523°C.
For these reasons, the polymer has improved thermal properties compared to the polymer obtained in Comparative Example 1. Next, the polymer thus obtained is
After filtering and defoaming, the NMP solution is passed through a nozzle with a hole diameter of 0.2 mm and 5 holes at a discharge speed of 5 m/min into an aqueous coagulation bath containing 30 wt% NMP at room temperature using a so-called semi-dry semi-wet spinning method. Spinning, 6m/
I wound it up at a speed of min. Next, the threads were washed with water and dried in a conventional manner, and then stretched on a hot plate at the temperatures shown in Table 2. Table 2 shows the maximum draw ratio (MDR) at which the fiber breaks at each temperature and the strength, elongation, and initial Young's modulus of the fiber obtained by winding the fiber at a draw ratio of 80% of the MDR.

[Table] As is clear from a comparison between Table 1 and Table 2, the polymer obtained by the method of the present invention has a large maximum fiber drawing ratio and provides drawn fibers with particularly excellent strength. Effects of the Invention According to the method of the present invention as described above, an aromatic polyamide copolymer having a high degree of polymerization and a high degree of regularity can be obtained, and this copolymer has excellent solubility and heat resistance. Excellent properties and crystallinity. Therefore, this copolymer can be easily molded into fibers, films, etc., and the physical properties of the resulting molded products are also very good.

Claims (1)

[Claims] 1 General formula (A) H ₂ N−Ar ₂ −NHCO−Ar ₁ −CONH−Ar ₃ −NH ₂ ...(A) [In the formula, Ar ₁ is a paraphenylene group, Ar ₂ is paraphenylene group or metaphenylene group, Ar ₃ represents [formula] or [formula]. (X represents -O-, _-SO2- , _-CH2- )];
General formula (B) ClCO- _Ar4 -COCl...(B) [ _Ar4 represents a paraphenylene group or a metaphenylene group. ] A method for producing an aromatic copolymer with high regularity, which comprises reacting an aromatic dicarboxylic acid chloride represented by the following. 2. The method for producing an aromatic polyamide copolymer according to claim 1, wherein Ar ₄ is a paraphenylene group. 3. The method for producing an aromatic polyamide copolymer according to claim 1, wherein Ar ₃ is [Formula] or [Formula]. 4. The method for producing an aromatic polyamide copolymer according to claim 1, wherein Ar ₂ and Ar ₄ are paraphenylene groups and Ar ₃ is [Formula]. 5. A method for producing an aromatic polyamide copolymer according to any one of claims 1 to 4, wherein the reaction is carried out in an aprotic amide solvent.