JPH04351637A - Production of molecular composite material from aromatic heterocyclic random copolymer - Google Patents

Abstract

PURPOSE:To produce a molecular composite material excellent in mechanical strengths, etc., by homogeneously dissolving a precursor of a specific arom. heterocyclic random copolymer and a matrix polymer in an org. solvent, removing the solvent from the soln., and thermally treating the resulting solid. CONSTITUTION:A precursor (e. g. a compd. of formula II) of an arom. heterocyclic random copolymer of formula I [wherein Ar and Ar' are each an arom. group; R is an optionally substd. alkyl; X is a dicarboxylic acid deriv. residue; and (m:n) is (0.01:99.99)-(99.99:0.01)] and a matrix polymer (e.g. an arom. polyamide) are homogeneously dissolved in an org. solvent (e.g. N-methyl-2-pyrrolidone) to give a soln. After the solvent is removed from the soln., the resulting solid is heated to cause a reaction to form thiazole rings in the precursor, giving a molecular composite material consisting of an arom. heterocyclic random copolymer of formula III and the matrix polymer.

Description

[Detailed description of the invention]

0001

[Field of Industrial Application] The present invention relates to a method for producing a molecular composite material consisting of an aromatic heterocyclic random copolymer and a matrix polymer, and in particular, it has excellent mechanical properties, etc.
This invention relates to a method for producing molecular composite materials suitable for use as structural materials for aircraft, automobiles, space equipment, etc.

0002

[Prior art and problems to be solved by the invention] In recent years,
2. Description of the Related Art So-called engineering plastics, which have excellent mechanical properties and heat resistance, have come to be widely used for the purpose of reducing the weight of aircraft, automobiles, etc. In addition, in order to improve strength and rigidity, composite materials such as FRP, which combine plastic materials and high-strength, high-elastic fibers such as carbon fiber, are being actively developed and are now in widespread practical use. .

It is known that the strength of these composite materials is greatly influenced by the interfacial adhesion between the fibers and the matrix resin, in addition to the strength of the plastic matrix and the fibers themselves used as reinforcing materials. . Furthermore, the quality of impregnating the reinforcing fiber preform with the matrix resin affects not only the manufacturing aspect but also the strength of the product. For these reasons, even if fibers or resins exhibiting high strength and high elasticity are used as materials, it is not always possible to obtain a composite material with excellent strength.

[0004] Therefore, by finely dispersing a so-called rigid polymer such as an aromatic polyamide down to the molecular level in a polymer serving as a matrix resin, a so-called polymer blend composite material (molecular composite material) was developed to overcome the above problems. However, attempts to obtain high-strength composite materials have been proposed and research and development efforts are underway.

[0005] Aromatic polymers suitably used in molecular composite materials include those having a heterocyclic ring such as a thiazole ring, imidazole ring, oxazole ring, or oxazinone ring in the repeating unit, and among them, there are those having a thiazole ring, etc. Due to its excellent mechanical strength, aromatic polythiazole is considered promising as a reinforcing polymer for molecular composite materials.

By the way, even if an attempt is made to manufacture a molecular composite material by simply mixing a reinforcing polymer such as aromatic polythiazole and a matrix polymer, due to the rigidity of the reinforcing polymer, the reinforcing polymer and matrix polymer The compatibility with the reinforcing polymer is generally not good, and it is difficult to obtain uniform dispersion of the reinforcing polymer into the matrix polymer. Unless the reinforcing polymer is uniformly dispersed in the matrix polymer, it is not possible to obtain a molecular composite with excellent mechanical properties. To this end, various attempts have been made so far.

For example, Japanese Patent Application Laid-open No. 1-287167 discloses a reinforcing polymer (A) consisting of a polyazole having a substantially rod-like skeleton and a matrix polymer (B) having fusibility.
) A method for producing a polymer composite comprising introducing into a coagulation bath a polymer solution mainly containing A method is disclosed in which a solution is immersed in a coagulation bath, passes through an apparently optically isotropic phase, and is then coagulated.

Further, Japanese Patent Publication No. 2-7976 discloses a reinforcing polymer A consisting of polyazole having a substantially rod-like skeleton, a glass transition temperature of 200° C. or more, a flow initiation temperature of 500° C. or less, and When the material is held at a temperature between the transition temperature and the flow start temperature for any period of time within 5 hours, the apparent crystal size formed is 25 Å.
Matrix polymer B consisting of a difficult-to-crystalline aromatic copolyamide as follows: A/(A+B)=0.15 to 0.
70 (by weight).

However, the method for producing a polymer composite disclosed in JP-A No. 1-287167 and JP-A No. 2-7
In the production of a composite material using the polymer composition disclosed in No. 976, uniform dispersion of the reinforcing polymer and matrix polymer cannot be expected to be very uniform, and the mechanical strength etc. of the resulting molecular composite material cannot be greatly improved. This seems to be because the reinforcing polymer exhibiting rigidity and the matrix do not have good compatibility, and therefore the reinforcing polymer is not sufficiently dispersed in the matrix polymer.

Therefore, instead of mixing the rigid aromatic polymer and the matrix polymer, the precursor of the rigid aromatic polymer and the matrix polymer or its precursor are uniformly mixed in an organic solvent, and the organic solvent is removed. Later, a method of converting the precursor into a rigid aromatic polymer by heating was proposed (Japanese Patent Laid-Open Nos. 64-1760 and 1983).
-1761).

[0011] According to the above method, a molecular composite material having relatively good mechanical strength etc. can be manufactured.

However, according to the research of the present inventor,
For example, using a thermoplastic resin as a matrix polymer for the purpose of hot-press molding of a molecular composite material, and using this and an aromatic polythiazole precursor,
When attempting to produce a molecular composite material by the method shown in No. 760 or JP-A No. 64-1761, an aromatic polyester formed by a thiazole ring-closing reaction is produced in the step of thermoforming a homogeneous mixture of a matrix polymer and a precursor. It was found that the thiazole agglomerated, resulting in a decrease in the mechanical properties of the molecular composite.

Therefore, an object of the present invention is to solve the above-mentioned problems and to provide a molecular composite material in which a rigid aromatic polymer as a reinforcing polymer is well dispersed in a matrix polymer, thereby having excellent mechanical strength etc. The object of the present invention is to provide a manufacturing method that enables

[0014]

[Means for Solving the Problems] In view of the above problems, as a result of intensive research, the present inventors have developed a precursor copolymer for an aromatic heterocyclic polymer: (1) a unit that forms an aromatic heterocycle and exhibits rigidity; , ■ If a random copolymer having a main chain with a structure in which units having a common or similar structure to the matrix polymer are randomly bonded is used, this precursor copolymer will be well dispersed in the matrix polymer,
They also discovered that even when this homogeneous mixture is heated, the rigid and rigid polymers do not aggregate, making it possible to form a molecular composite material with excellent physical properties, thereby completing the present invention.

That is, the method of the present invention for producing a molecular composite material consisting of an aromatic heterocyclic random copolymer and a matrix polymer comprises (1) (a) the following formula:

embedded image (where Ar and Ar′ are aromatic residues, R is a substituted or unsubstituted alkyl group, X is a residue of a dicarboxylic acid derivative, m and n are both integers, m:n
is 0.01:99.99 to 99.99:0.01. ) A homogeneous solution of a precursor of an aromatic heterocyclic random copolymer represented by The thiazole ring-closing reaction occurs, resulting in the following formula

A molecular composite consisting of an aromatic heterocyclic random copolymer represented by [Chemical Formula 4] (Ar, Ar', X, m, and n are all the same as those in Chemical Formula 3 above) and a matrix polymer. It is characterized by:

The present invention will be explained in detail below. Precursor copolymer In the present invention, the precursor of the aromatic heterocyclic random copolymer (hereinafter referred to as precursor copolymer) which becomes the reinforcing polymer of the molecular composite material has the following formula:

embedded image (where Ar and Ar′ are aromatic residues, R is a substituted or unsubstituted alkyl group, X is a residue of a dicarboxylic acid derivative, m and n are both integers, m:n
is 0.01:99.99 to 99.99:0.01. ).

This precursor copolymer comprises (a) an aromatic diaminodithiol compound in which the hydrogen atom of a thiol group is substituted with a substituted or unsubstituted alkyl group, (b) an aromatic diamino compound, and (c) a dicarboxylic acid derivative. It can be manufactured from.

(a) Aromatic diaminodithiol compound in which the hydrogen atom of a thiol group is substituted with a substituted or unsubstituted alkyl group (hereinafter referred to as compound (a) for simplicity)
is the following general formula

embedded image (where Ar is an aromatic residue and R is a substituted or unsubstituted alkyl group). Here, the aromatic residue Ar is not limited to a benzene ring, but may be an aromatic ring in which two or more benzene rings are condensed, or may be a ring in which two or more benzene rings are bonded, such as biphenyl. Further, the positional relationship between the amino group and the thioether group on both sides may be symmetrical or point symmetrical with respect to the aromatic residue. Examples of this compound (a) are:

[C7] etc.

This compound (a) can be synthesized from an aromatic diaminodithiol compound, which is a compound having an amino group and a thiol group on both sides of an aromatic residue. As the aromatic diaminodithiol compound, compounds shown in the above-mentioned chemical formula 7 in which the alkyl group R is replaced with a hydrogen atom can be used. used in the form of salt.

The alkyl group R bonded to the thiol group of the aromatic diaminodithiol compound is a substituted or unsubstituted alkyl group. Examples of unsubstituted alkyl groups include isopropyl group, ethyl group, n-propyl group, n-butyl group, s
Examples include ec-butyl group and tert-butyl group. As the alkyl group, secondary and tertiary alkyl groups are particularly preferred.

The substituted alkyl group is preferably an alkyl group substituted with a carboxyl group, an ester group, a cyano group, a benzene group, or the like. Incidentally, when having such a substituent, the alkyl group does not particularly need to be a secondary one. As an alkyl group having a substituent,
for example,

[Chemical formula 8] etc.

[0022] Among the above six substituted alkyl groups, in those in which the two ester groups shown above are substituted, the alkyl group bonded to the oxygen atom in the ester bond is not limited to the methyl group, but also has 2 carbon atoms. to 10 alkyl groups.

In particular, when the hydrogen atom of the thiol group of the aromatic diaminodithiol compound is substituted with an alkyl group having a cyano group or an alkyl group having an ester group,
Obtained precursor copolymer (polymer of chemical formula 3 above)
This is preferred because the thiazole ring closure reaction occurs at a relatively low temperature. Furthermore, the solubility of these precursor copolymers in organic solvents such as N-methyl-2-pyrrolidone is improved.

The above-mentioned alkyl group is used as its halide, ie, alkyl halide, and from this and the above-mentioned aromatic diaminodithiol compound (salt thereof),
Compound (a) is synthesized by the method described below. Note that as the halide, the above-mentioned alkyl group brominated products, chlorinated products, iodides, etc. can be used.

In the synthesis of compound (a), the above-mentioned salt of the aromatic diaminodithiol compound and an alkyl halide are reacted in an alkaline aqueous solution. The alkaline aqueous solvent used may be water or a mixed solvent of water and alcohol (ethanol and/or methanol) in which a basic salt such as sodium hydroxide is dissolved. By making the solvent alkaline, the salt of the aromatic diaminodithiol compound can be easily dissolved. It also increases the nucleophilicity of the thiol group and promotes substitution reactions. Note that the alkali concentration of the alkaline aqueous solvent is preferably 30% by weight or less.

[0026] This substitution reaction can be carried out at a temperature in the range of 0°C to 100°C. If the temperature is less than 0°C, the reaction rate becomes slow, which is not preferable. Moreover, if the temperature exceeds 100°C, side reactions will occur, which is not preferable. A more preferable reaction temperature is 0°C to 95°C.

[0027] There is no particular restriction on the reaction time, but it is generally 2 to
About 24 hours is sufficient.

[0028] In order to increase the reaction rate, it is preferable to stir the solution. Furthermore, the reaction rate can be increased by using an excessive amount of alkyl halide.

Furthermore, cetyltrimethylammonium chloride, n-butyltriphenylphosphonium bromide,
Tetraphenylphosphonium bromide, 18-crown-6
etc. can be added as a phase transfer catalyst to increase the reaction rate. Such a phase transfer catalyst rapidly causes the reaction between the salt of the aromatic diaminodithiol compound and the alkyl halide to proceed.

By carrying out the substitution reaction under the above conditions,
A monomer in which the hydrogen atom of the thiol group of the salt of an aromatic diaminodithiol compound is substituted with an alkyl group (compound (a)
) can be obtained.

In the reaction for synthesizing compound (a),
The reaction between the salt of the aromatic diaminodithiol compound and the alkyl halide proceeds as follows. Here, 2,5-diamino-1,4-benzenedithiol dihydrochloride is used as an example of the salt of the aromatic diaminodithiol compound. Moreover, in the formula, X-R represents an alkyl halide.

[Chemical formula 9]

Next, (b) the aromatic diamino compound (hereinafter referred to as compound (b) for simplicity) is preferably an aromatic diamino compound having a bendable structure, and aromatic diamino compounds such as diphenyl ether, biphenyl, etc. Diamines with residues can be used. Specifically, the following formula

[Chemical formula 10] Those represented by can be suitably used.

[0033] In order to improve the compatibility between the aromatic heterocyclic random copolymer and the matrix polymer, this compound (b) has a structure that is the same or similar to a part of the matrix polymer to be mixed. It is better to choose what you have.

Further, examples of dicarboxylic acid derivatives include those in which each carboxyl group is substituted as shown below.

[Chemical formula 11]

[0035] The residues of the above dicarboxylic acid derivatives include relatively short chain (2 to 10 carbon atoms) alkylene groups,
Examples include aromatic residues as shown below. In addition, as an example of the dicarboxylic acid, aromatic dicarboxylic acids are preferable, and terephthalic acid and isophthalic acid are particularly preferable.

[Chemical formula 12]

Note that the dicarboxylic acid derivative is not limited to one type, but two or more types may be used in combination.

Next, a method for producing the precursor copolymer will be explained. The above-described compound (a), compound (b), and dicarboxylic acid derivative (c) are dissolved in an organic solvent in a desired blending ratio, and these three are copolymerized. Preferably, a homogeneous solution of compound (a) and compound (b) is first prepared, and dicarboxylic acid derivative (c) is added thereto.

Compound (a) in solution using an organic solvent
and compound (b) in the final aromatic heterocyclic random copolymer, the ratio of the part that changes to a rigid linear chain part and the part that becomes a flexible chain part (i.e., m and n), but the concentrations of compound (a) and compound (b) are determined as appropriate depending on the intended use of the aromatic heterocyclic random copolymer. In the present invention, m:n is 0.01:99.99 to 99
．． Compound (a) and compound (b) are blended in a ratio of 99:0.01.

The amount of dicarboxylic acid derivative (c) is equal to or greater than the total molar amount of compound (a) and compound (b). In addition, compound (a), compound (b) and dicarboxylic acid derivative (
The total concentration of c) is preferably about 0.1 to 2 mol/liter. If the concentration exceeds 2 mol/liter, it becomes difficult to dissolve each component, which is not preferable.

As the organic solvent, amide organic solvents can be suitably used. As the amide organic solvent, N
-Methyl-2-pyrrolidone, hexamethylphosphoric triamide, N,N-dimethylacetamide, etc., and these can be used alone or in a mixed solution. In addition, to increase reactivity, up to 5% LiC
Chlorides such as 1, CaCl2, etc. may be added.

Compound (a), compound (b) and dicarboxylic acid derivative (c) are polymerized to form a precursor copolymer (
The above-mentioned polymer of Chemical Formula 3) is produced, and the polymerization reaction temperature at this time is preferably -20°C to +50°C. If the temperature is below -20°C, sufficient polymerization reaction will not occur,
Furthermore, the degree of polymerization of the resulting aromatic heterocyclic random copolymer also becomes low. On the other hand, since a thiazole ring-closing reaction may occur at a temperature of about 100°C, the upper limit of the polymerization reaction temperature is set at +50°C for safety reasons. More preferably,
The temperature should be in the range of -20°C to +30°C.

In the above polymerization reaction, it is preferable to stir the solution in order to increase the reaction rate. Further, the reaction time is not particularly limited, but may generally be about 1 to 24 hours.

By carrying out the polymerization reaction under the above conditions,
A precursor copolymer having a large degree of polymerization can be obtained without causing a thiazole ring closure reaction. The intrinsic viscosity of the precursor copolymer obtained is ηinh = 1.0 to 1.8 (N
-Methyl-2-pyrrolidone, 30°C).

This polymerization reaction is thought to proceed as follows. Here, as an example of compound (a), 2,5
Using an alkyl group-substituted product of -diamino-1,4-benzenedithiol dihydrochloride, 4 is used as an example of compound (b).
,4'-diaminodiphenyl ether (4-amino-
p-phenoxyaniline) and terephthalic acid dichloride is used as an example of the dicarboxylic acid derivative (c). Note that m and n represent the degree of polymerization.

[Chemical formula 13]

The obtained precursor copolymer can be washed and dried by known methods.

Matrix Polymer Matrix polymers used in the present invention include polyamide, polyimide, polyamideimide and the like. These resins have good compatibility with the precursor copolymer and can provide molecular composites with excellent mechanical strength. As the matrix polymer, aromatic polyamide is particularly preferred.

Method for producing molecular composite material (1) First, the above precursor copolymer and matrix polymer are dissolved in an organic solvent in which both can be well dissolved. As such a solvent, amide organic solvents such as N-methyl-2-pyrrolidone, dimethylsulfoxide, and N,N-dimethylacetamide can be suitably used.

In blending the precursor copolymer and matrix polymer, even if the blending amount of the precursor copolymer is extremely small, there is a reinforcing effect; however, in the end, the weight ratio of the aromatic heterocyclic random copolymer to the matrix polymer is 1:1. It is preferable to set the ratio to be in the range of 100 to 1:1. If the blending ratio of the reinforcing polymer, the aromatic heterocyclic random copolymer, is too high, the presence of the aromatic heterocyclic random copolymer becomes too dense, causing the aromatic heterocyclic random copolymers to aggregate with each other, resulting in poor dispersion at the molecular level. This is thought to reduce the mechanical strength of the molecular composite. A more preferable blending ratio is 1:50 to 1:3.

The precursor copolymer and matrix polymer may be dissolved by any method as long as a homogeneous solution is obtained. For example, solutions of a precursor copolymer and a matrix polymer may be prepared and then mixed to form a homogeneous solution, or a matrix polymer may be added to a solution in which the precursor copolymer is dissolved to form a homogeneous solution. Alternatively, both may be dissolved in one type of solvent at a time. The concentration of the final solution is preferably such that the total amount of precursor copolymer and matrix polymer is 1 to 20% by weight.

[0050] The mixing time varies somewhat depending on the matrix polymer and solvent used, but the mixing time is preferably about 6 hours to 30 days. Further, the temperature during mixing is preferably -15 to 150°C.

Preparation and mixing of the precursor copolymer and matrix polymer solutions is preferably carried out under an inert gas atmosphere such as nitrogen gas or argon gas, or in vacuum.

[0052] After preparing a homogeneous solution, the solvent is evaporated to dry it, but in reality, it is better to dry it after forming it into a film by casting or spinning it. Since a solution of a precursor copolymer substituted with an alkyl group as described above has high liquid crystallinity, it is easy to spin a composite of the precursor copolymer and matrix polymer from an organic solvent. In order to increase the liquid crystallinity of the solution of the precursor copolymer, it is basically better to lengthen the alkyl group bonded to the thiol group, but in reality it is necessary to increase the length of the alkyl group bonded to the thiol group. It is better to use length.

[0053] The composite of the precursor copolymer and the matrix polymer can be dried by a known method.

(2) Next, the composite of the precursor copolymer and matrix polymer obtained above is heated to cause a thiazole ring closure reaction in the precursor copolymer to obtain a molecular composite.

During this heating, the alkyl group (R) of the precursor copolymer is eliminated and a thiazole ring is formed at that site, forming an aromatic heterocyclic random copolymer. If the precursor copolymer obtained by the reaction formula shown in Chemical Formula 13 above is used, an aromatic heterocyclic random copolymer having the following structural formula is formed.

[Chemical formula 14]

[0056] The heating temperature of the homogeneous mixture of the precursor copolymer and the matrix polymer varies depending on the type of matrix polymer used, but is generally between 250°C and
The temperature shall be 400°C. No formation of thiazole rings is observed when heated below 250°C.

Heating may be performed not only by a constant heating temperature but also by a heating program that changes the temperature in steps. For example, after heating at 120 °C for 30 minutes, increase the temperature to 350 °C in 30 minutes, and then heat at 350 °C for 30 minutes.
A heating program that holds the temperature for 0 minutes may also be used.

According to the above method, the precursor copolymer uniformly dispersed in the matrix polymer at the molecular level becomes the aromatic heterocyclic random copolymer as it is, so the aromatic heterocyclic random copolymer is dispersed in the matrix polymer at the molecular level. It will be uniformly dispersed, resulting in a molecular composite with good mechanical properties.

[0059]Also, the aromatic heterocyclic random copolymer used in the present invention has structural parts having flexibility arranged randomly, and these parts are set so as to have a high affinity for the matrix polymer. (for example, by creating a site capable of hydrogen bonding), thereby preventing a decrease in mechanical strength due to insufficient adhesion at the interface between the aromatic heterocyclic random copolymer molecules and the matrix polymer molecules and aggregation of the aromatic heterocyclic random copolymers. can.

[0060]

EXAMPLES The present invention will be explained in detail with reference to the following specific examples. Example 1 (1) Synthesis of precursor copolymer The following formula

[Chemical formula 15] 9 mmol of compound (a) represented by and the following formula

[Chemical 1
6] was dissolved in 15 ml of N-methyl-2-pyrrolidone (hereinafter referred to as NMP) solution under an argon atmosphere to prepare a homogeneous solution.

[0061] This solution was cooled with ice in a container, and compound (c) was added.
Then, 10 mmol of 2-chloroterephthalic acid chloride was added. The temperature of the solution was gradually raised while stirring, and when it reached room temperature, the temperature was maintained and the reaction was continued for an additional 6 hours. The resulting emerald green solution was poured into a large amount of methanol. Note that this operation was performed while stirring methanol.

After continued stirring for 30 minutes, the mixture was filtered and further refluxed with a water-methanol solution overnight to remove the solvent. The resulting polymer was dried in vacuo at 100° C. for 24 hours. The yield was 99.8%. The intrinsic viscosity ηinh of this polymer was 1.20 (dl/g). The intrinsic viscosity was measured in NMP at a polymer concentration of 0.5 g.
/dl and carried out at 30°C by Ubbelohde method. The structure of the obtained polymer (precursor copolymer) appears to be as follows.

[Chemical formula 17]

(2) Production of molecular composite The obtained precursor copolymer and aromatic polyamide (manufactured by Toray Industries, Inc., TX)
-1), a molecular composite material was manufactured by the method shown below. In addition, here, the thiazole ring-closing reaction occurs at a site having a thiazole ring exhibiting rigidity in the aromatic heterocyclic random copolymer serving as the reinforcing molecule (a site corresponding to the parenthetical portion surrounded by m in Chemical Formula 17 above). A plurality of molecular composites (films) were prepared with a proportion of up to 12% by weight (based on the total amount of aromatic heterocyclic random copolymer and matrix polymer).

First, desired amounts of the precursor copolymer and TX-1 were taken, added to NMP so that the total amount was 5% by weight, and mixed at 60° C. for one week. Next, the homogeneous NMP solution was cast onto a glass plate and heated at 80°C under normal pressure.
After removing the solvent, a transparent isotropic film (thickness 30μ
m) was obtained.

[0065] This film was heated to 340°C in vacuum.
Heat treatment was performed for 30 minutes. When the obtained film was subjected to TG-DTA measurement and IR spectrum observation, the formation of a thiazole ring was confirmed. In addition, the tensile modulus and tensile strength of this film were determined according to JIS K
Measured in accordance with 7127. The results of measuring the tensile modulus are shown in FIG. 1, and the results of measuring the tensile strength are shown in FIG. Furthermore, Figure 1
As described above, the horizontal axis of the graph in FIG. 2 is the proportion (% by weight) of the rigid portion having a thiazole ring in the aromatic heterocyclic random copolymer in the molecular composite.

Comparative Example 1 A film was produced in the same manner as in Example 1 except that only TX-1 was added to NMP without adding the precursor copolymer. The tensile modulus and tensile strength of this film were measured in the same manner as in Example 1. The measurement results of tensile modulus are shown in Figure 1, and the measurement results of tensile strength are shown in Figure 2, respectively for Example 1.
The results are also shown.

Comparative Example 2 Using the compound (a) and compound (c) used in Example 1, a polybenzothiazole precursor (n=0 in the above chemical formula 17) was prepared in the same manner as in Example 1. things) were synthesized.

A molecular composite material (film) was produced in the same manner as in Example 1 (2) except that this polybenzothiazole precursor was used. The tensile modulus and tensile strength of the obtained molecular composite material were measured in the same manner as in Example 1. The measurement results of the tensile modulus are shown in FIG. 1, and the measurement results of the tensile strength are shown in FIG. 2, together with the results of Example 1.

As can be seen from FIGS. 1 and 2, the molecular composite according to the present invention has the same tensile modulus as the molecular composite having a reinforcing polymer that is not copolymerized, but has a lower elongation. has increased, and the tensile strength has improved.

Example 2 A precursor copolymer was produced in the same manner as in Example 1, except that the molar ratio of compound (a) and compound (b) was 8:2. Using this precursor copolymer and a polymer (matrix polymer) having the structure shown below, a composite film consisting of the precursor copolymer and matrix polymer was produced in the same manner as in Example 1. The mixing ratio of the precursor copolymer and the matrix polymer is such that the content of the site that exhibits rigidity (the portion that forms a thiazole ring upon heating and becomes a rigid structure) is 10% by weight.
It was set so that

[Chemical formula 18]

For the plurality of films obtained above,
Each was heat-treated to a maximum temperature of 230 to 350°C to obtain a molecular composite material (film). The tensile modulus and tensile strength of the obtained film were measured in the same manner as in Example 1. The results of measuring the tensile modulus are shown in FIG. 3, and the results of measuring the tensile strength are shown in FIG.

Comparative Example 3 A molecular composite material (film) was produced in the same manner as in Example 2, except that the polybenzothiazole precursor synthesized in Comparative Example 2 was used instead of the precursor copolymer. The tensile modulus and tensile strength of this film were measured in the same manner as in Example 2. The measurement results of the tensile modulus are shown in FIG. 3, and the measurement results of the tensile strength are shown in FIG. 4, together with the results of Example 2.

As can be seen from the graph shown in FIG. 3, in the molecular composite material according to the present invention, the heat treatment temperature of the film consisting of the precursor copolymer and the matrix polymer is 2.
The thiazole ring-closing reaction is completed from around 50℃ 350
As the temperature increases to around ℃, the tensile modulus improves. In comparison, in the film of Comparative Example 3 using a polybenzothiazole precursor that is not a copolymer, the tensile modulus decreases at temperatures higher than around 280°C. This seems to be because the matrix polymer melts due to heating and the polybenzothiazole aggregates. Regarding the tensile strength, in the film of Comparative Example 3, the tensile strength decreases when the heat treatment temperature is about 280° C. or higher, but in the film of Example 2, it remains at an almost constant high level.

[0074]

Effects of the Invention As detailed above, in the method of the present invention, (a) a moiety having a thiazole ring exhibiting rigidity;
b) An aromatic heterocyclic random copolymer with a structure in which parts that are flexible and have high compatibility with the matrix polymer are randomly arranged is used as the reinforcing polymer, so reinforcement in the matrix polymer is used. The dispersion of the polymer becomes good. In addition, physical properties are also improved due to increased adhesion between the reinforcing polymer and the matrix polymer. Furthermore, when introducing the aromatic heterocyclic random copolymer as a reinforcing polymer, since the precursor copolymer is mixed with the matrix polymer, the aromatic heterocyclic random copolymer is well dispersed in the matrix polymer. Therefore, in the molecular composite according to the present invention,
There is no aggregation of reinforcing polymers, which occurs when polybenzothiazole is used as a reinforcing polymer, and the resulting molecular composite material has good mechanical properties.

Since the molecular composite material obtained by the method of the present invention has good mechanical strength, it can be used in a wide range of applications including automobile parts, aircraft parts, and space equipment.

[Brief explanation of the drawing]

FIG. 1 is a graph showing the measurement results of the tensile modulus of films in Example 1, Comparative Example 1, and Comparative Example 2.

FIG. 2 is a graph showing the results of measuring the tensile strength of films in Example 1, Comparative Example 1, and Comparative Example 2.

FIG. 3 is a graph showing the measurement results of the tensile modulus of films in Example 2 and Comparative Example 3.

FIG. 4 is a graph showing the results of measuring the tensile strength of films in Example 2 and Comparative Example 3.

Claims (5)

[Claims] Claim 1: A method for producing a molecular composite material comprising an aromatic heterocyclic random copolymer and a matrix polymer, comprising: (1) (a) the following formula: [Formula 1] (where Ar and Ar' are group, R is a substituted or unsubstituted alkyl group, X is a residue of a dicarboxylic acid derivative, m and n are both integers, m:n
is 0.01:99.99 to 99.99:0.01. ) A homogeneous solution of a precursor of an aromatic heterocyclic random copolymer represented by A thiazole ring-closing reaction occurs, thereby producing a random aromatic heterocycle represented by the following formula [Formula 2] (wherein Ar, Ar', A method characterized in that it produces a molecular composite consisting of a copolymer and a matrix polymer. 2. The method according to claim 1, wherein the aromatic residue Ar' is a diphenyl ether group. 3. The method according to claim 1 or 2, wherein the dicarboxylic acid derivative is an aromatic dicarboxylic acid derivative. 4. The method according to claim 3, wherein the aromatic dicarboxylic acid derivative is substituted or unsubstituted terephthalic acid dichloride or isophthalic acid dichloride. 5. The method according to claim 1, wherein the matrix polymer is polyamide,
A method characterized in that the material is polyimide or polyamideimide.