JP2512803B2 - Aromatic polyamide - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a novel heat-meltable aromatic polyamide having high heat resistance.

[Prior art]

Aromatic polyamides obtained by reacting aromatic diamines or aromatic diisocyanates with aromatic dicarboxylic acids or their derivatives have hitherto been excellent in heat resistance due to various excellent physical properties and good heat resistance. It is expected to be widely used in the fields where

However, aromatic polyamides which have been conventionally developed often have excellent mechanical properties and heat resistance, but all have drawbacks in that they have poor moldability and high water absorption.

For example, formula (II) Aromatic polyamides with a basic skeleton represented by (DuPont's product; trademark kevlar) have excellent characteristics such as flame resistance, heat resistance, high tensile strength and high elastic modulus, but have a clear glass transition temperature. The thermal decomposition temperature is about 430 ° C, the processing temperature and the thermal decomposition temperature are close to each other, and it is difficult to process when used as a molding material. It is only used. In addition, when used as a substrate for electric / electronic parts, the water absorption is as high as 4.5%, and it is apparent that this has an adverse effect on dimensional stability, insulation properties, solder heat resistance, and the like.

[Problems to be Solved by the Present Invention]

An object of the present invention is to obtain an aromatic polyamide having low water absorption, which has excellent processability in addition to the excellent heat resistance inherent in aromatic polyamide.

[Means for solving problems]

The present inventors have conducted extensive studies to achieve the above object, and as a result, found a novel aromatic polyamide.

That is, the present invention has the formula (I) And the positions of the two carbonyl groups in the formula are either the ortho, meta or para positions of the benzene nucleus, and n
Is an aromatic polyamide that is a positive number from 1 to 1,000.

The aromatic polyamide of the present invention has the formula (III) as a diamine component. It is a novel aromatic polyamide obtained by using a diamine represented by the formula: bis4,4'-bis (3-aminophenoxy) biphenyl and polymerizing this with benzenedicarboxylic acid or a derivative thereof.

The benzenedicarboxylic acids used in this method include phthalic acid, isophthalic acid and terephthalic acid. Further, as the derivative of benzenedicarboxylic acid, benzenedicarbonyldihalogenide such as phthaloyl dichloride, phthaloyl dibromide, isophthaloyl dichloride, isophthaloyl dibromide, terephthaloyl dichloride, terephthaloyl dibromide, phthalic anhydride and the like. Examples thereof include acid anhydrides and dialkylbenzenedicarboxylates such as dimethyl phthalate, diethyl phthalate, dimethyl isophthalate, diethyl isophthalate, dimethyl terephthalate and diethyl terephthalate.

These benzenedicarboxylic acids or their derivatives may be used alone or in admixture of two or more.

That is, the aromatic polyamide of the present invention is characterized in that 4,4′-bis (3-aminophenoxy) biphenyl is used as a diamine component, and in addition to the heat resistance originally possessed by the aromatic polyamide, it has excellent processability. It is a thermoplastic aromatic polyamide.

Since the aromatic polyamide in the present invention is thermoplastic in addition to excellent heat resistance, it can be extrusion-molded and injection-molded, and is further melted as a base material for space / aircraft, a base material for electric / electronic parts. It is an extremely useful aromatic polyamide that can be expected to be used for various purposes as a raw material for high-strength and high-heat-resistant fiber by the spinning method.

The method for producing the aromatic polyamide of the present invention is not particularly limited, and a conventionally known method can be employed. For example, the aromatic polyamide can be obtained by the following method.

That is, benzenedicarboxylic acid such as 4,4′-bis (3aminophenoxy) biphenyl and isophthalic acid, benzenedicarbonyl chloride such as terephthaloyl dichloride, and benzenedicarboxylic acid derivative such as dimethyl terephthalate are polymerized in a solvent to produce aromatic compounds. A group polyamide is obtained.

As the solvent used in this method, for example, N, N-
Dimethylformamide, N, N-dimethylacetamide,
N, N-diethylacetamide, N, N-dimethylmethoxyacetamide, N-methyl-2-pyrrolidone, 1,3-dimethyl-2-imidazolidinone, N-methylcaprolactam, dimethyl sulfoxide, tetramethylurea, hexamethylphospho Luamide, isoquinoline, 2,4-lutidine, pyridine, γ-picoline, β-picoline, α-picoline, 2,6-lutidine, quinoline, triethylamine,
Tributylamine, tripentylamine, N, N-dimethylaniline, N, N-diethylaniline, dichloromethane, chloroform, carbon tetrachloride, methyl ethyl ketone,
Examples include acetone, cyclohexanone, acetophenone, tetrahydrofuran, benzene, toluene, xylene, nitrobenzene, phenol, cresylic acid, o-cresol, m-cresol, p-cresol, p-chlorophenol, o-chlorophenol, and water.

These solvents may be used alone or as a mixture of two or more, depending on the type of reaction raw material monomer and the polymerization technique.

When benzenedicarbonyldichlorides are used as the reaction raw material monomer, a dehydrochlorinating agent is usually used together.

As the dehydrochlorinating agent used, triethylamine, tributylamine, tripentylamine, N, N-dimethylaniline, N, N-diethylaniline, pyridine, α-picoline, β-picoline, γ-picoline, 2,4- Examples include lutidine, 2,6-lutidine, quinoline, isoquinoline, sodium hydroxide, potassium hydroxide, sodium carbonate, potassium carbonate, lithium carbonate, sodium hydrogen carbonate, calcium oxide, lithium oxide, ethylene oxide, propylene oxide and the like.

When benzenedicarboxylic acids are used as the reaction raw material monomer, a condensing agent is usually used.

As the condensing agent used, sulfuric anhydride, thionyl chloride, sulfite, picryl chloride, phosphorus pentoxide, phosphite-pyridine condensing agent, triphenylphosphine-hexachloroethane condensing agent, propyl phosphoric anhydride- N-methyl-2-pyrrolidone-based condensing agents and the like can be mentioned.

The reaction temperature is generally 150 ° C or lower, preferably 30 ° C or lower. The reaction pressure is not particularly limited, and the reaction can be carried out at normal pressure.

The reaction time varies depending on the type of reaction raw material monomer, the polymerization method, the type of solvent, the type of dehydrochlorinating agent, the type of condensing agent, and the reaction temperature. Let react for sufficient time to complete. Usually, 10 minutes to 24 hours are sufficient.

By such a reaction, an aromatic polyamide having a repeating unit represented by the following formula (I) is obtained.

(In the formula, n represents a positive number of 1 to 1,000.) That is, any of the above-mentioned (I It is possible to obtain an aromatic polyamide having a repeating unit of).

The aromatic polyamide of the present invention is characterized by using 4,4'-bis (3-aminophenoxy) biphenyl as a reaction raw material monomer and a benzenedicarboxylic acid derivative such as benzenedicarboxylic acid or benzenedicarbonyldichloride. .

However, in order to improve the thermal stability and moldability of the aromatic polyamide, the end-capping with a monovalent amine, a monovalent acid or an acid derivative does not cause any problem in the present invention. That is, a part of the diamine component is an aromatic, aliphatic or alicyclic monoamine, and a part of the benzenedicarboxylic acid or benzenedicarboxylic acid derivative is an aromatic, aliphatic or alicyclic monocarboxylic acid or monocarbonyl chloride. There is no problem in replacing with a monocarboxylic acid derivative.

Examples of monoamines that are partially substituted include aniline, toluidines, chloroanilines, aminophenols, naphthylamines, aminobiphenyls,
Examples thereof include aminophenyl phenyl ethers, alkylamines, cyclohexylamine and the like. Examples of monocarboxylic acids include benzoic acid, naphthalenecarboxylic acids, benzophenonecarboxylic acids, diphenylethercarboxylic acids, propionic acid and cyclohexanecarboxylic acid. Further, as the monocarboxylic acid derivative, benzoyl chloride, naphthalene carbonyl chloride,
Examples thereof include benzophenone carbonyl chlorides, diphenyl ether carbonyl chlorides, propionyl chloride and cyclohexane carbonyl chloride.

When the aromatic polyamide of the present invention is supplied to melt molding, the following fillers and the like used in ordinary resin compositions may be used to such an extent that the object of the invention is not impaired. That is, graphite, carborundum, silica stone powder, molybdenum disulfide, wear resistance improving materials such as fluororesins, glass fibers, carbon fibers, boron fibers, silicon carbide fibers, carbon whiskers, asbestos, metal fibers, ceramic fibers and other reinforcing materials , Antimony trioxide, magnesium carbonate, calcium carbonate, etc. flame retardant improver, clay, mica, etc. electrical property improver, asbestos, silica, graphite etc. tracking resistance improver, barium sulfate,
Acid resistance improvers such as silica and calcium metasilicate, thermal conductivity improvers such as iron powder, zinc powder, aluminum powder and copper powder, and other glass beads, glass spheres, talc, diatomaceous earth, alumina, silica balun, hydration Alumina, metal oxides, coloring agents and the like.

〔Example〕

Hereinafter, the present invention will be described in more detail with reference to Examples and Comparative Examples.

The physical properties in Examples and Comparative Examples were measured by the following methods.

Logarithmic viscosity; 0.50 g of polyamide powder was dissolved in 100 ml of hexamethylphosphoramide and then measured at 35 ° C Glass transition temperature (Tg); DSC (Shimadzu DT-40 series, DSC
-41M) 5% weight loss temperature; DTA-TG (Shimadzu DT-40 in air
Series, DTG-40M) Melt viscosity; Shimadzu Koka type flow tester CFT500A with a load of 100 kg (Example 1) 4,4'-bis in a container equipped with a stirrer and a nitrogen inlet pipe under a nitrogen atmosphere 5.53 g (0.015 mol) of (3-aminophenoxy) biphenyl and 48.6 g of N-methyl-2-pyrrolidone were charged and dissolved, and then triethylamine 3.0 was added.
36 g (0.030 mol) was added and cooled to -15 ° C. After that, stir well and terephthalic acid dichloride 3.045g
(0.015 mol) was charged all at once, and stirring was continued at 0 ° C. for 2 hours and then at room temperature for 1 hour. The viscous polymer solution thus obtained was filtered and discharged into methanol with vigorous stirring to precipitate a white powder. The white powder was filtered, washed with methanol, and dried under reduced pressure at 180 ° C. for 12 hours to obtain 7.10 g (yield 95.1%) of polyamide powder. The polyamide powder had an inherent viscosity of 1.23 dl / g, a glass transition temperature of 237.5 ° C. and a 5% weight loss temperature in air of 473 ° C.

The results of elemental analysis of the obtained polyamide powder are as follows.

The infrared absorption spectrum of the obtained polyamide powder is shown in FIG. In this spectrum diagram, remarkable absorption is observed near 1660 cm ^-1, which is the characteristic absorption band of amide.

Further, the obtained polyamide powder was dissolved in N-methyl-2-pyrrolidone, and then cast on a glass plate.
It was heated for 1 hour at 250 ° C. for 2 hours to obtain a colorless and transparent polyamide film. The tensile strength of this polyamide film was 1,020 kg / cm ² , and the tensile elongation was 25%. Both measurement methods are based on ASTM D-882.

The water absorption of this film was 0.8%. The measuring method is based on ASTM D-570-63.

(Example 2) The same procedure as in Example 1 was carried out except that terephthalic acid dichloride in Example 1 was changed to isophthalic acid dichloride,
7.02 g of white polyamide powder with a logarithmic viscosity of 1.30 dl / g (yield 94
%) Was obtained.

The glass transition temperature of this polyamide powder was 227.0 ° C, and the 5% weight loss temperature in air was 478.6 ° C.

The results of elemental analysis of the obtained polyamide powder are as follows.

The infrared absorption spectrum of the obtained polyamide powder is shown in FIG. In this spectrum diagram, remarkable absorption is observed near 1660 cm ^-1, which is the characteristic absorption band of amide.

A polyamide film was obtained in the same manner as in Example 1 using the obtained polyamide powder. The polyamide film had a tensile strength of 1,150 kg / cm ² , a tensile elongation of 27% and a water absorption of 0.75%.

Example 3 3.045 g of terephthalic acid dichloride in Example 1 (0.
015 mol) to 1.523 g (0.0075 g) of terephthalic acid dichloride
Mol) and isophthalic acid dichloride 1.522 g (0.0075 mol)
Example 1 was repeated except that the logarithmic viscosity was 1.23.
7.1 g (yield 95.1%) of white polyamide powder of dl / g was obtained.

The glass transition temperature of this polyamide powder was 234 ° C, and the 5% weight loss temperature in air was 478 ° C.

A polyamide film was obtained in the same manner as in Example 1 using the obtained polyamide powder. The tensile strength of this polyamide film was 1,100 kg / cm ² , and the tensile elongation was 27%.

(Example 4) In a container equipped with a stirrer and a nitrogen inlet tube, 7.37 g (0.020 mol) of 4,4'-bis (3-aminophenoxy) biphenyl and 65 g of N-methyl-2-pyrrolidone were placed in a nitrogen atmosphere. After charging and dissolving, triethylamine 4.048
g (0.040 mol) was added and cooled to -15 ° C. afterwards,
Strengthen the agitation, and terephthalic acid dichloride 3.800 g (0.01
(87 mol) was charged all at once and stirred at 0 ° C. for 1.5 hours.
Then, 0.548 g (0.0039 mol) of benzoyl chloride was charged, and stirring was continued at 0 ° C. for 2 hours and further at room temperature for 1 hour. The obtained polymer solution was filtered and discharged into methanol with vigorous stirring to precipitate a white powder, which was separated by filtration. The polyamide powder was washed with methanol and then dried under reduced pressure at 180 ° C. for 12 hours to obtain 9.3 g (yield 95%) of polyamide powder. The logarithmic viscosity of this polyamide powder is 0.55
dl / g. When the melt viscosity of the obtained polyamide was measured, it was 5,800 poise at 360 ° C. The obtained strand was light yellow, transparent, highly flexible, and extremely tough.

The heat distortion temperature of the molded product obtained by compression molding this polyamide powder at 340 ° C. and 150 kg / cm ² for 15 minutes was 225 ° C. Measurement method is ASTM D-648, load 18.6kg
/ cm ²

Comparative Example 1 2.16 g (0.02 mol) of p-phenylenediamine in a nitrogen atmosphere in a container equipped with a stirrer and a nitrogen introducing tube.
And 56.2 g of N-methyl-2-pyrrolidone were charged and dissolved, 4.048 g (0.040 mol) of triethylamine was added, and the mixture was cooled to -15 ° C. After that, the stirring was strengthened, 3.800 g (0.0187 mol) of terephthalic acid dichloride was charged all at once, and the mixture was stirred at 0 ° C. for 1.5 hours. Then, 0.548 g (0.0039 mol) of benzoyl chloride was charged, and stirring was continued for 2 hours at 0 ° C. and for 1 hour at room temperature. The resulting polymer solution was filtered and discharged into vigorously stirred methanol to give a white powder. After filtration, this polyamide powder was washed with methanol and then dried under reduced pressure at 180 ° C. for 12 hours to obtain 4.4 g (yield 97.7%) of polyamide powder. When the glass transition temperature of this polyamide powder was measured, no clear glass transition temperature was shown. The melt viscosity was measured at 370 ° C. and 400 ° C. using a Koka type flow tester, but melt flow did not occur at any temperature.

〔The invention's effect〕

The present invention provides a completely novel aromatic polyamide having excellent heat resistance, which is inherently possessed by aromatic polyamide, excellent processability, and low water absorption.

[Brief description of drawings]

1 and 2 are examples of infrared absorption spectrum of the polyamide powder of the present invention.

Claims (1)

(57) [Claims] 1. A formula (I) And the positions of the two carbonyl groups in the formula are either the ortho, meta or para positions of the benzene nucleus, and n
Is an aromatic polyamide that is a positive number from 1 to 1,000