JPH10316758A - Production of poly(p-benzamide) copolymer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a simple process for producing a poly(p-benzamide) excel lent in mechanical properties, which process comprises copolymerizing a poly(p- benzamide) with another polymer in a reaction field being a homogenous solu tion of a poly(p-benzamide) having a sufficient molecular weight and active reactive groups. SOLUTION: This process comprises adding a polymer (C) having carboxyl groups and/or amino-reactive functional-group-containing polymer to a homogeneous transparent poly(p-benzamide)-containing solution obtained by polycondensing p-aminobenzoic acid in a concentration of 0.08-0.15 mol/l in a solution containing an amidic solvent (A), a phosphite compound (B) and lithium chloride and calcium chloride to polymerize the poly(p-benzamide) with polymer (C). Polymer C is desirably a carboxylic polyolefin or a carboxylic polyamide.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for producing a copolymer of poly (p-benzamide) having a sufficient molecular weight and another polymer.

[0002]

2. Description of the Prior Art As described in U.S. Pat. No. 3,600,350, poly (p-benzamide), a rigid wholly aromatic polyamide, has excellent mechanical properties. Therefore, when a poly (p-benzamide) chain having a sufficient molecular weight is bonded to another kind of polymer chain, the former effectively acts as a reinforcing component of the latter in the obtained copolymer, and excellent mechanical properties are obtained. It is expected to give.

Rigid poly (p-benzamide) does not have melt processability, but has relatively high solubility in organic solvents among rigid wholly aromatic polyamides. Therefore, in order to bond the reinforcing component poly (p-benzamide) to another polymer, it is ideal to carry out a reaction between the two polymers by a homogeneous solution reaction. Therefore, if a homogeneous solution of poly (p-benzamide) having a reactive end can be provided, and the solution is used as a homogeneous interpolymer reaction field between the poly (p-benzamide) terminal and another polymer. If this is achieved, it becomes possible to produce a copolymer in which both polymer chains are linked.

A method for preparing a solution of poly (p-benzamide) is described in US Pat. No. 3,600,350, in which poly (p-benzamide) is synthesized by a self-polycondensation reaction of paraaminobenzoyl chloride.
However, this monomer requires many steps in its synthesis, is inconvenient to handle such as having difficulty in storage, and has the problem of generating hydrochloric acid which is highly corrosive to metal devices and the like.

[0005] Further, in this production method, as specified in the patent, there is a problem that the reaction solution is gelled when an attempt is made to produce poly (p-benzamide) having a sufficient molecular weight. In order to prepare a solution containing poly (p-benzamide), the resulting gel is once cut in a high-speed blender, and the resulting fine powder is washed with water and alcohol, and then dried. After the treatment, it must be newly dissolved in an organic solvent, and the process is extremely complicated. Furthermore, in such a step, the reaction activity of the poly (p-benzamide) terminal is lost, and it becomes difficult to produce a copolymer with another polymer.

[0006] The above-mentioned polyamide synthesis is based on a condensation reaction between a classic amino group and an acylated modified carboxyl group. As another method for synthesizing a polyamide, a carboxyl group is not acylated without acylation. A direct synthesis method that is used as is is known. In this synthesis method, the handling of the monomer is easy and there is no generation of hydrochloric acid.
It is practically used for industrial production of nylon 66 by direct polymerization of 6-diaminohexane.

Although this direct synthesis method has conventionally been difficult to apply to the synthesis of non-melting aromatic polyamides, there have recently been several direct synthesis methods of various wholly aromatic polyamides by solution polymerization using a condensing agent. Have been reported. In this method, poly (p-benzamide) can be directly synthesized from a p-aminobenzoic acid monomer which is easy to handle.

These are described, for example, in JP-A-51-30896 and JP-A-57-141422, J. Polym. Sci .: Polym. C
hem. Ed., 13: 1373 (1975), ibid., 20: 2081 (1
982), pp. 20, 1907 (1985), a method using a phosphite compound as a condensing agent is also described in J. Polym. Sci .: Pol.
ym. Lett. Ed., Vol. 19, p. 343 (1981), a method using a phosphine compound as a condensing agent is disclosed in Makromol. Chem., Rapid Co.
mmun., Vol. 6, p. 111 (1985) discloses a method using silicon chloride as a condensing agent.

In the above method using a phosphine compound, the poly (p-benzamide) produced is separated and precipitated from the solution because the solvent used has no affinity for the polyamide, and the poly (p-benzamide) having a sufficient molecular weight as a product is obtained. -Benzamide) cannot be obtained as a completely transparent and uniform solution, and the method using silicon chloride is a direct synthesis method, but has a problem that hydrochloric acid and difficult-to-separate silica particles are produced as by-products, and the polymerization rate is low. There was a problem that the reaction time required 24 hours. In addition, none of the references described a solution production of a copolymer of another polymer and poly (p-benzamide).

In addition, as suggested by US Pat. No. 3,600,350, in order for poly (p-benzamide) to have sufficient physical properties, a poly (p-benzamide) having a molecular weight having an inherent viscosity of 0.7 dL / g or more is required. (P-benzamide) must be used.

[0011]

The problem to be solved by the present invention is to prepare a poly (p-benzamide) by using a homogeneous solution of poly (p-benzamide) having a sufficient molecular weight and an active reactive group as a reaction field. And to provide a simple method for producing a poly (p-benzamide) copolymer having excellent mechanical properties by copolymerizing a poly (p-benzamide) with a polymer of another kind.

[0012]

Means for Solving the Problems As a result of intensive studies, the present inventors have found that polycondensation of p-aminobenzoic acid in a specific concentration range using a phosphite compound in an amide-type solvent containing lithium chloride and calcium chloride. The inventors have found that the above-mentioned problems can be solved by obtaining a solution, and have completed the present invention.

That is, the present invention relates to (1) a solution containing an amide type solvent (A), a phosphite compound (B), lithium chloride and calcium chloride, and having a concentration of 0.08 to 0.1.
A polymer (C) having a functional group reactive with a carboxyl group and / or an amino group is added to a homogeneous and transparent poly (p-benzamide) -containing solution obtained by polycondensing 5 mol / L of p-aminobenzoic acid. A process for producing a poly (p-benzamide) copolymer, characterized by adding and polymerizing the poly (p-benzamide) and the polymer (C);

(2) The polymerization of poly (p-benzamide) with a polymer (C) by a condensation reaction via a phosphite compound (B) in the presence of a phosphite compound. (1) The method for producing a copolymer according to (1), wherein (3) the polymer (C) is a polyolefin having a carboxyl group.
Or the method for producing the poly (p-benzamide) copolymer according to (2), and

(4) The method for producing a poly (p-benzamide) copolymer according to the above (1) or (2), wherein the polymer (C) is a polyamide having a carboxyl group. It is a thing.

[0016]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail.
The present invention polycondensates p-aminobenzoic acid having a concentration of 0.08 to 0.15 mol / L in a solution containing an amide type solvent (A), a phosphite compound (B), lithium chloride and calcium chloride. The polymer (C) having a functional group reactive with a carboxyl group and / or an amino group is added to the homogeneous and transparent poly (p-benzamide) -containing solution obtained by the above method to obtain poly (p-benzamide) and polymer (C). And a method for producing a poly (p-benzamide) copolymer.

The amide type solvent (A) used in the present invention has a site in which hydrogen adjacent to the nitrogen atom of the amide group has been replaced by a methyl group or the like, and is an organic solvent capable of dissolving metal salts such as lithium chloride and calcium chloride. And N-methyl-2-pyrrolidinone (NMP), N, N
-Dimethylacetamide and N, N, N ', N'-tetramethylurea. Among them, NMP is preferable. These may be used alone or in a mixture of two or more.

In the reaction of the present invention, a tertiary amine is added in an amount not exceeding 200 parts by weight per 100 parts by weight of the amide type solvent (A) in order to accelerate the polycondensation reaction in addition to the amide type solvent (A). Typical examples thereof include pyridine, lutidine, picoline and imidazole, and these may be used alone or in a mixture of two or more. Of these, pyridine is preferred.

In the present invention, it is essential to add a metal salt in the above-mentioned solvent for the purpose of improving the solubility in the polymer and increasing the reaction activity, and the type and amount of the metal salt are important for promoting the polycondensation reaction. Factors. Examples of the metal salt include lithium chloride and calcium chloride, and it is preferable to use them together in the concentration ranges of 0.5 to 4.2% and 0.5 to 10.0%, respectively. Here, the concentration (%) of the metal salt is defined as the total amount of the amide type solvent (A) and the tertiary amine being 1
It is a gram amount for 00 mL.

The present invention is characterized in that the self-condensation reaction of p-aminobenzoic acid as a monomer proceeds continuously through a phosphite compound (B) as a condensing agent. Examples of the phosphite compound (B) include triphenyl phosphite, diphenyl phosphite, tri-o-tolyl phosphite, di-o-tolyl phosphite, and tri-m-
Tolyl phosphite, di-m-tolyl phosphite, tri-
p-tolyl phosphite, di-p-tolyl phosphite, tri-o-chlorophenyl phosphite,

Di-o-chlorophenyl phosphite, tri-
m-chlorophenyl phosphite, di-m-chlorophenyl phosphite, tri-p-chlorophenyl phosphite,
Di-p-chlorophenyl phosphite can be mentioned, and among them, triphenyl phosphite is preferable. If no phosphite compound (B) is present, no reaction takes place, and the amount of addition is preferably 0.6 to 3 mol per mol of p-aminobenzoic acid.

In the present invention, the polycondensation of p-aminobenzoic acid is carried out by dissolving in a solvent system composed of the above components. It is extremely important, and is 0.08 to 0.15 mol / L, preferably 0.11 to 0.14 mol / L. Here, the concentration of p-aminobenzoic acid is defined as a molar amount based on the total liter amount of the amide type solvent (A) and the tertiary amine.

If the concentration of p-aminobenzoic acid in the reaction system is too low, the molecular weight of the resulting poly (p-benzamide) is not sufficient, and if the concentration is too high, poly (p-benzamide) precipitates. Since the system becomes turbid or gelled, a uniform and transparent solution cannot be obtained. Mixing of each component is performed in the range of room temperature to the reaction temperature, and it is efficient if stirring is performed. The order of mixing these components is not particularly limited, but a method of adding the condensing agent to a uniform solution in which all components other than the phosphite compound (B) as the condensing agent are mixed is preferable.

In particular, since the dissolution rate of the metal salt is lower than that of the other components, if the condensing agent is added simultaneously with the other components, the polycondensation proceeds under substantially different component concentration conditions, resulting in poor reproducibility. In many cases, the molecular weight of the resulting poly (p-benzamide) is reduced. The condensation reaction is started by the addition of a condensing agent, and by finally adding the condensing agent as a final component, poly (p-benzamide) can be synthesized with good reproducibility.

The reaction temperature is in the range of 60 to 180 ° C., preferably 90 to 130 ° C. The reaction depends on the reaction temperature, but can be performed in a relatively short time. For example, at a reaction temperature of 90 ° C to 130 ° C, the reaction can be completed within 2 hours. The reaction is preferably performed in an inert gas atmosphere.

J. Polym. Sci .: Polym. Chem. Ed., Volume 20, 1
As described on page 907 (1985), when the system is brought into contact with air during the reaction, the reaction is inhibited, probably due to moisture absorption in the solvent, and the molecular weight of the produced poly (p-benzamide) decreases. Therefore, it is preferable not to release the reaction system to the outside air until the growth of the poly (p-benzamide) chain is completed. In this sense, it is preferable that all components of the solution are added at the start of the reaction.

The molecular weight of a rigid wholly aromatic polyamide is generally evaluated by the inherent viscosity of a dilute solution dissolved in a concentrated sulfuric acid solvent. In the present invention, the molecular weight is evaluated by using concentrated sulfuric acid as described in Examples. Performed by the inherent viscosity of the solution. The higher the inherent viscosity, the higher the molecular weight, but the production method of the present invention provides a homogeneous and transparent solution containing poly (p-benzamide) having an inherent viscosity of 0.70 dL / g or more. Can be

Particularly, a tertiary amine is used and the reaction temperature is 90 to 90.
At 130 ° C., the inherent viscosity can be increased to 1.2 dL / g or more. In each case, poly (p-
Benzamide) is produced in high yield (96-100%).

The term “uniformly transparent” as used herein means that each component including poly (p-benzamide) is completely dissolved in the amide-type solvent (A) without agglomeration. Absent. The resulting poly (p-benzamide) -containing solution is uniformly transparent at room temperature of -10 ° C to 40 ° C and has storage stability of 5 months or more.

The terminal group of poly (p-benzamide) in the obtained solution has a reaction activity, and the production of a copolymer by the reaction of poly (p-benzamide) in the solution with another polymer It is possible.

Examples of the other polymer used here include a polymer (C) having a functional group reactive with a carboxyl group and / or an amino group. The term “reactivity” as used herein means a reactivity that can form a covalent bond between polymers by reacting with a carboxyl group or an amino group which is a terminal group of poly (p-benzamide). Examples of the functional group include an amino group and an epoxy group, and examples of the functional group reactive with the amino group include a carboxyl group, an acylated carboxyl group, an epoxy group, an isocyanato group, and a dibasic acid anhydride ring. . Among them, polymers having a carboxyl group are particularly preferred.

These functional groups may be present at any position of the polymer (C), and may be present as a terminal of the polymer chain, a constituent unit of the chain itself, or a pendant group of the chain. When such a functional group is at the terminal of the chain, a block copolymer with poly (p-benzamide) is obtained, and when the functional group is present at other positions, a graft copolymer with poly (p-benzamide) is obtained.

Since the production of the copolymer according to the present invention is based on a so-called interpolymer reaction in which a heterogeneous polymer whose chain growth has been completed in advance is difficult, it is difficult to produce a general-purpose copolymer by a reaction between a polymer and a monomer. It is possible to adjust the molecular weight of the polymer segment, and there is an advantage that the molecular weight does not need to be sacrificed.

The polymer (C) is not particularly limited as long as it can be dissolved in a poly (p-benzamide) -containing solution and can bind to the poly (p-benzamide) terminal. Typical examples thereof include polyolefin having a carboxyl group and polyolefin having a carboxyl group. Polyamides. Examples of the polyolefin having a carboxyl group include polyacrylic acid, polymethacrylic acid, a copolymer containing acrylic acid and / or methacrylic acid as a vinyl polymer component, and a polyolefin having a carboxyl group at a chain end.

Specific examples of the copolymer include a copolymer of styrene and methacrylic acid, and specific examples of a polyolefin having a carboxyl group at the chain end include a copolymer of butadiene and acrylonitrile having carboxyl groups at both ends. Copolymers can be mentioned.

Examples of the polyamide having a carboxyl group include aliphatic polyamides having a carboxyl group at a chain end such as nylon 6, nylon 11, nylon 18, and nylon 66, and aromatic polyamides such as poly (m-phenylene isophthalamide). Examples thereof include polyamides and aromatic polyamides into which pendant carboxyl groups have been introduced. Specific examples of the aromatic polyamide having a pendant carboxyl group introduced therein include those obtained by polycondensing isophthalic acid dichloride and 3,5-diaminobenzoic acid with m-phenylenediamine.

In order to add the polymer (C) to the poly (p-benzamide) -containing solution, the polymer (C) may be added alone or in a form dissolved in a solvent in advance. A reaction accelerator such as a catalyst may be added together. However, it is preferable that a mineral acid such as hydrochloric acid that causes unnecessary decomposition or a side reaction does not coexist. For satisfactory formation of the copolymer, it is important that the solution is a homogeneous reaction field in which both polymers are completely dissolved. The reaction temperature here depends on the type of the polymer (C) and is not particularly limited, but generally includes a range of 25 ° C to 180 ° C.

In the present invention, when the polymer (C) has a carboxyl group or an aromatic amino group, the condensation reaction via the phosphite compound (B) can be applied to the bonding with poly (p-benzamide). It has been found that the reaction conditions for producing a solution containing poly (p-benzamide) can be applied as they are. In this case, the production of poly (p-benzamide) and the production of its copolymer can be carried out sequentially in the same reaction system and at the same temperature, which is extremely efficient. At this time, when the phosphite compound (B) is consumed during the synthesis of poly (p-benzamide) or when the formation of the copolymer is performed more quickly, the phosphite compound (B) is newly added to the polymer (C). ) Is preferably added.

After completion of the reaction, components other than the polymer can be removed by washing with a solvent such as an alcohol in accordance with a conventional method. The resulting copolymer has a rigid poly (p-benzamide) chain which is introduced in a uniform form in which phase separation is suppressed, thus effectively acting as a reinforcing component to improve mechanical properties. When (C) is transparent, the obtained copolymer can also maintain a transparent appearance.

Rigid poly (p-benzamide) has a very low dissolution rate in a solvent, so that once separated poly (p-benzamide)
-Benzamide) to obtain a solution,
A longer time is required than in the method of the present invention, and the formation of the copolymer becomes insufficient due to the deactivation of the terminal groups during the operation.

[0041]

EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples. These examples are illustrative of specific embodiments of the present invention, and the present invention should not be limited to the scope thereof. The evaluation method used in the examples is as follows.

(1) Yield The reaction solution was poured into methanol to precipitate poly (p-benzamide), which was repeatedly washed and dried in boiling methanol, weighed and calculated.

(2) Inherent Viscosity As shown in Equation 1, the inherent viscosity (η _inh ) is determined from the time of falling through the capillary. The above dried poly (p-
Benzamide) in concentrated sulfuric acid (96%) at 0.1 g / dL
Was determined at 30 ° C. using an Ubbelohde viscometer.

[0044]

[Formula 1] η _inh = ln (T / T _o ) / C (dL / g)

[0045] (wherein, T / T _o is the ratio of the flow time / flow time of pure solvent of the solution, C is the concentration of polymer in the solution (g
/ DL). )

(3) Tensile properties A film sample was cut out to a width of 3 mm, and a tensile test was performed at 25 ° C. using an Autograph 2000 manufactured by Shimadzu Corporation at an initial gauge interval of 10 mm and a pulling speed of 1 mm / min.
Tensile modulus, tensile strength and elongation at break were each 4
It was determined as the average of two measurement points.

(4) Dynamic Mechanical Properties A film sample was cut out to a width of 4 mm, and a temperature rising rate of 5 ° C./min, a gauge length of 10 mm, a tensile mode of 1 Hz, a nitrogen atmosphere, and a DMS200 manufactured by Seiko Denshi Kogyo were used.
The storage elastic modulus was determined in a temperature range of 5 ° C to 260 ° C.

(Production Example 1) A flask equipped with a nitrogen inlet, a stirring blade, and a condenser was charged with 50 mL of NMP and 10 mL of NMP.
Pyridine, 1 g of lithium chloride, 3 g of calcium chloride, and a predetermined amount of p-aminobenzoic acid shown in Table 1 at 115 ° C.
To the homogeneous mixture obtained by mixing with stirring at a temperature, triphenyl phosphite in an equimolar amount to p-aminobenzoic acid is added, and while maintaining the temperature, stirring is continued to perform polycondensation of p-aminobenzoic acid. The reaction was performed.

FIG. 1 shows the relationship between the reaction time and the inherent viscosity in the example of Table 1c. As is clear from FIG.
Chain growth of poly (p-benzamide) was completed within 20 minutes. At any time, the poly (p-benzamide) -containing solution was homogeneous and transparent, and the solution was 115 ° C.
When cooled to any temperature from to −10 ° C., a uniform and transparent state was maintained.

The concentration of p-aminobenzoic acid was changed from a to f (0.0
Table 1 shows the appearance of the solution at 25 ° C., the inherent viscosity of poly (p-benzamide) at a reaction time of 150 minutes, and the yield at 25 ° C. for the reaction examples changed at 7 to 0.20 mol / L). From Table 1, a specific concentration range of p-aminobenzoic acid (b-d) was converted to poly (p-) having an inherent viscosity of 0.7 dL / g or more.
It can be seen that a homogeneous and transparent solution obtained by obtaining (benzamide) in a high yield is produced.

[0051]

[Table 1]

Example 1 In a poly (p-benzamide) -containing solution 150 minutes after the start of the reaction obtained in Production Example 1 (c in Table 1), while maintaining the temperature at 115 ° C., Dainippon Ink and Chemicals, Ltd. Co., Ltd. 29.1 g copolymer of styrene and methacrylic acid (molar ratio of styrene / methacrylic acid = 97 /
3) dissolved in 374 mL of NMP and 2.01
g of triphenyl phosphite was added and dissolved, and stirring was continued for 45 minutes while maintaining the temperature to conduct the condensation reaction between the amino group at the poly (p-benzamide) terminal and the carboxyl group of the styrene-methacrylic acid copolymer. Let it be done.

The obtained homogeneous and transparent solution was poured into methanol to precipitate a product, which was repeatedly washed in boiling methanol, and then dried to obtain a copolymer. Next, the obtained graft copolymer was compression-molded at 260 ° C. using a hydraulic press to form a film. Table 2 shows the tensile properties of the obtained transparent copolymer films.

Comparative Example 1 The copolymer of styrene and methacrylic acid used in Example 1 was compression-molded at 260 ° C. by a hydraulic press to form a film. Table 2 shows the tensile properties of the obtained films. Comparison with Example 1 shows that the introduction of the poly (p-benzamide) graft chain improved the mechanical properties of the copolymer of styrene and methacrylic acid.

[0055]

[Table 2]

(Comparative Example 2) Instead of the solution containing poly (p-benzamide) 150 minutes after the start of the reaction obtained in the production example of Example 1, the inherent viscosity of the same composition = 1.36 dL / g
The procedure of Example 1 was repeated, except that a poly (p-benzamide) -containing solution obtained by mixing poly (p-benzamide) powder, NMP, a metal salt and pyridine at 115 ° C. was used. Was attempted, and the product was formed into a film and the tensile properties were evaluated in the same manner. In this method, the dissolution of poly (p-benzamide) required 6 hours or more, and the obtained film was poor in transparency and also poor in tensile properties as shown in Table 2. These results indicate that the formation of the copolymer is insufficient.

Example 2 In the solution containing poly (p-benzamide) obtained in Production Example 1 (Table 1c) 150 minutes after the start of the reaction, while maintaining the temperature at 115 ° C., 8.1 g of a copolymer of butadiene and acrylonitrile which is liquid at room temperature and has carboxyl groups at both ends (acrylonitrile component = 26% by weight, product number 51)
9) and 0.30 g of triphenyl phosphite were added and dissolved, stirring was continued for 120 minutes while maintaining the temperature, and the amino group at the poly (p-benzamide) terminal and the carboxyl group of the butadiene-acrylonitrile copolymer were added. Was carried out.

The resulting reaction solution was poured into methanol to precipitate a product, which was repeatedly washed in boiling methanol.
After drying, a copolymer was obtained. The resulting block copolymer was moldable with a tack-free rubbery substance at room temperature.
Thus, an elastomer moldable from a butadiene-acrylonitrile copolymer was obtained by introducing a poly (p-benzamide) block chain.

(Production Example 2) 1.83 g of 3,5-diaminobenzoic acid, 11.68 g of m-phenylenediamine and 24.36 g of isophthaloyl dichloride were combined with 15 g of lithium chloride, 34 mL of pyridine and 300 mL of NMP.
And dissolved at 0 ° C. for 20 minutes, then
The solution obtained by continuously stirring at 5 ° C. for 60 minutes was poured into methanol, washed with boiling methanol, and dried to obtain a modified poly (m-phenylene isophthalamide) having a pendant carboxyl group in a part of the diamine component. Obtained.

Example 3 In the poly (p-benzamide) -containing solution obtained in Production Example 1 (Table 1c) 150 minutes after the start of the reaction, while maintaining the temperature of 115 ° C., The resulting modified poly (m-phenylene isophthalamide) 16.5
g dissolved in 500 mL of NMP and 2.3 mL
Is added and dissolved, and the mixture is stirred for 120 minutes while maintaining the reaction temperature, and condensation between the amino group at the terminal of poly (p-benzamide) and the carboxyl group of modified poly (m-phenylene isophthalamide) The reaction was allowed to run.

The obtained solution was poured into methanol to precipitate a product, which was repeatedly washed and dried in boiling methanol to obtain a graft copolymer. The obtained copolymer was compression-molded at 350 ° C. using a hydraulic press to form a film. FIG. 2 shows the dynamic mechanical properties of the obtained transparent copolymer film.

Comparative Example 3 Poly (m-phenylene isophthalamide) manufactured by Teijin Limited was compression molded at 350 ° C. by a hydraulic press to form a film. FIG. 2 shows the dynamic mechanical properties of the obtained film. As shown in FIG.
It can be seen that the mechanical properties of poly (m-phenylene isophthalamide) were improved in the range from room temperature to high temperature by the introduction of a (benzamide) graft chain.

[0063]

According to the present invention, poly (p-benzamide) is copolymerized with another polymer by using a homogeneous solution of poly (p-benzamide) having a sufficient molecular weight and an active reactive group as a reaction field. It is possible to provide a simple method for producing a poly (p-benzamide) copolymer having excellent mechanical properties.

[Brief description of the drawings]

FIG. 1 is a graph showing the relationship between the reaction time and the inherent viscosity (η _inh ) of poly (p-benzamide) in Example 1 of the present invention (c in Table 1).

FIG. 2 is a diagram showing the relationship between temperature and storage elastic modulus, which are dynamic mechanical properties of films obtained in Example 3 (solid line) and Comparative Example 3 (dashed line) of the present invention.

Claims (4)

[Claims] 1. Polycondensation of p-aminobenzoic acid having a concentration of 0.08 to 0.15 mol / L in a solution containing an amide type solvent (A), a phosphite compound (B), lithium chloride and calcium chloride. The polymer (C) having a functional group reactive with a carboxyl group and / or an amino group is added to the homogeneous and transparent poly (p-benzamide) -containing solution obtained by the above-mentioned process, so that the poly (p-benzamide) and the polymer (C )) And a method for producing a poly (p-benzamide) copolymer. 2. The method according to claim 1, wherein the polymerization of the poly (p-benzamide) and the polymer (C) is carried out by a condensation reaction via the phosphite compound (B) in the presence of the phosphite compound. A method for producing the copolymer according to the above. 3. The method for producing a poly (p-benzamide) copolymer according to claim 1, wherein the polymer (C) is a polyolefin having a carboxyl group. 4. The polymer according to claim 1, wherein the polymer (C) is a polyamide having a carboxyl group.
3. The method for producing a poly (p-benzamide) copolymer according to item 1.