JPH0321636A - Aromatic polyamide oligomer having terminal unsaturated group and production thereof - Google Patents

Abstract

PURPOSE:To obtain the subject oligomer useful as a raw material for thermosetting aromatic polyamide having excellent processability by reacting an aromatic diamine, an aromatic monoamine having terminal unsaturated group and an aromatic dicarboxylic acid dihalide in the presence of a hydrogen halide acceptor. CONSTITUTION:The objective oligomer of formula [A and A' are radically polymerizable unsaturated group (A may be same as A'); R is H or lower alkyl; R1 and R2 are bivalent aromatic group; n is 1-15] can be produced by reacting (A) an aromatic diamine (e.g. m-phenylenediamine), (B) an aromatic monoamine having terminal unsaturated group (e.g. m-isopropenylaniline) and (C) an aromatic dicarboxylic acid dihalide (preferably isophthaloyl dichloride) in the presence of a hydrogen halide acceptor.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a polyoligomer useful as a heat-resistant synthetic resin, particularly a heat-resistant aromatic polyamide imparted with thermosetting properties, and a method for producing the same. [Prior Art] As the demands of the plastics industry become more sophisticated, industrial materials with special properties are required, and this trend is rapidly developing as the industrial sector becomes more sophisticated. The demand for improved heat resistance is felt in plastics, films, fibers,
This is also to add heat resistance to industrial materials in fields that require heat resistance, such as laminates, laminates, and adhesives, to expand the market, and to expand into a wide range of new fields with new functions.

In response to these demands, a group of synthetic resins called engineering plastics, such as aromatic polyamide, bonoimide, borisulfone, and polyphenylene oxide, have already been developed, and these plastics have new functions different from conventional synthetic resins. Aromatic polyamides, also known as aramids, are one of them, and are being industrially produced as industrial products and are opening up new demand fields. Examples of aromatic polyamides include polyparaphenylene terephthalamide (product name: Kevlar) and polymetaphenylene isophthalamide (product name:
Nomex or HT-1) is a typical type. These polyamides are. All of them are classified as thermoplastic synthetic resins, and a type of polyamide that can thermoset oligomers has not yet been discovered. For this reason, although it has a higher melting point than normal thermoplastic synthetic resins, as the temperature rises, hardness, strength, etc. inevitably decrease, and it is virtually impossible to use it above the softening point. there were. The reason why there was no thermosetting aromatic polyamide is as follows.
This is thought to be because the melting point was generally much higher than that of conventional thermoplastic synthetic resins, and the introduction of unsaturated bonds was considered to have a high risk of causing undesirable gelation during the molding process. [Problem to be solved by the invention] Aromatic polyamide is an excellent heat-resistant polymer that is relatively stable even at considerably high temperatures, has excellent electrical properties and mechanical strength, and has high chemical stability. ．． The purpose of the present invention is to further improve mechanical strength and chemical stability at high temperatures without losing these properties. [1,000 Steps to Solve the Problems The present inventors have found that when molded as a molding material or as a laminate, it has a relatively low melting point, can be molded into a desired shape under heat and pressure, and is In order to obtain an aromatic polyamide that can be cured under relatively mild conditions and has sufficient heat resistance, mechanical strength, chemical stability, etc. after curing,
An aromatic diamine, an aliphatic monoamine having a terminal unsaturated group, and an aromatic dicarboxylic acid dihalide are reacted in the presence of a hydrogen halide acceptor to obtain an unsaturated polyamide oligomer having a terminal unsaturated group represented by the general formula. They discovered that this product can be cured in the presence of a radical-generating catalyst, and that this cured aromatic polyamide has the above-mentioned excellent properties, leading to the completion of the present invention. The aromatic polyamide oligomer having a terminal unsaturated group of the present invention can be illustrated by the following reaction formula as an example. (Left below) (Aromatic dicarboxylic acid dihalide) (Aromatic polyamide oligomer) In order for the reaction to proceed smoothly, an acceptor for the by-produced hydrogen chloride is required, and generally tertiary amine or caustic It is convenient to use alkali. In this case, n is 1 from l
A value of about 5, preferably about 3 to 7 is advantageous because of ease of moldability, and polymerization at this stage is not particularly necessary. This reaction is generally performed by mixing amines in an aqueous phase and acid chloride in an inert organic solvent that does not dissolve in water to perform an interfacial polycondensation reaction, or by dissolving both in an inert organic solvent and condensing them at low temperatures. It can be carried out by low-temperature solution polycondensation reaction. Examples of aromatic diamines that can be used in the present invention include metaphenylene diamine, 4.4'-diaminodiphenylmethane, and 4.4'-diaminodiphenylpropane. 3
．． 3'-dimethyl-4.4'-diaminodiphenylmethane, 4,4'-diaminodiphenyl ether, 3.4'-diaminodiphenyl ether, 3.3'-diaminodiphenyl sulfone, 4.4'-diaminodiphenyl ether enylsulfone, dianisidine, 2,4-t-lylenediamine,
2.4/2.6 - }Lylene diamine mixture, 1.
3-bis(3-aminophenoxy)benzene and the like can be used, and two or more types can be used in combination. As the aromatic monoamine having a terminal unsaturated group, m-
Examples include isobrobenylaniline, p-improbenylaniline, 0-aminostyrene, m-aminostyrene, p-aminostyrene, etc., but terminally unsaturated polyamide oligomers can be synthesized at low temperatures, and the resulting polyamide oligomers are stable. m-isobrobenylaniline, p-isobrobenylaniline, and p-aminostyrene are most commonly used from the viewpoints of efficiency, manpower, cost, etc. Note that this amine may be a free amine or a hydrohalide salt, but in the case of a hydrohalide salt, it is necessary to use a tertiary amine etc. that binds to the hydrogen halide at the same time. becomes. Further, as the aromatic dicarboxylic acid dihalide that can be used in the present invention, dichlorides of aromatic dibasic acids are convenient, and typical examples include terephthalic acid dichloride, isophthalic acid dichloride, phthalic acid dichloride, or mixtures thereof. From a practical standpoint, phthalic acid dichloride produces an aromatic polyamide that has insufficient heat resistance, and when terephthalic acid dichloride is used, the heat resistance is sufficient, but the resulting aromatic polyamide oligomer has a high melting point. Therefore, isophthalic acid dichloride is the most suitable for the purpose of the present invention. This synthesis reaction proceeds relatively stoichiometrically, so after calculating n in the [Al formula], the necessary amounts of terminally unsaturated aromatic monoamine, aromatic diamine, and aromatic dicarboxylic acid dihalide are reacted. If precise adjustment is required, the molar ratio can be determined by a simple test. As already explained, the composition of the aromatic polyamide oligomer obtained by this reaction can be easily selected, and it can be molded at temperatures below 200°C. The aromatic polyamide oligomer with unsaturated end groups synthesized according to the present invention can be cured by heat curing or in combination with a radical-generating catalyst, making it possible to significantly improve heat resistance. There is no need to limit the radical generation catalyst, but the peroxide type is suitable industrially, and the molding temperature is 1.
If the temperature exceeds 00°C, a so-called high-temperature decomposition type, such as dicumyl peroxide type, is used. The appropriate amount to use is 1 to 3 phr. Further, the combined use of a monomer copolymerizable with an unsaturated bond is possible when the monomer dissolves the aromatic polyamide oligomer, and the range of application is particularly wide when n in the formula AI is small. Although the combined use of monomers promotes the softening of the entire condensation system and improves moldability and workability, it tends to reduce the heat resistance of the hardened aromatic polyamide, so the amount added should be determined according to the purpose. is necessary.

It goes without saying that the aromatic polyamide oligomer having unsaturated end groups according to the present invention can be used in combination with reinforcing agents, fillers, mold release agents, coloring agents, other polymers as low shrinkage agents, etc., as necessary.

Next, examples are shown below to help understand the present invention. [Example 1 (Example 1) 20.3 g (0.1 mol) of isophthalic acid dichloride and dimethylformamide were placed in a four-piece Iβ separable flask equipped with a reflux condenser, a dropping funnel, a thermometer, and a stirrer. Charge (DMF) long and cool to below 10°C. Next, 3.4′-diaminodiphenyl ether 16.67
g (0.083 mol), triethylamine 16.87
g (0.167 mol). Weigh and mix 75g of DMF,
Pour into a separable flask. Next, 4.43 g (0.033 mol) of p-imbropenylaniline, 3.33 g (0.033 mol) of triethylamine, and 25 DMF.
Weigh and mix 10g of the mixture and drop it into a separable flask. During this time, keep the temperature of the reaction mixture below 10°C. After completion of the reaction under i, the temperature of the reaction mixture was kept at 10°C or less, and the reaction was continued for 2 hours. Continue stirring. The reaction mixture is then gradually added to a large amount of water with vigorous stirring to precipitate crystals. The precipitated crystals are filtered with suction, washed with water, and dried. m. p. Figure 1 shows the infrared absorption spectrum at 170-185°C. The elemental analysis value is C, 74.05%: H. 4. 2%:N. 8.1
The theoretical value at 3% is C. 73.90%: H. 4.59%:N. 8.2
Good agreement was shown at 1%. (Examples 2 to 5) (The following is a blank space) Table 1 Polycondensation recipe FIB position/g) si. of R of aromatic monoamine compound. An aromatic polyamide oligomer having an unsaturated terminal group was synthesized in the same manner as in Example 1 except that the substituent positions g1 and n were changed. (Hereinafter in the margin) (Hereinafter in the margin) m p. of the synthesized aromatic polyamide oligomer having an unsaturated terminal group. and elemental analysis values are shown in the table below. Further, their infrared absorption spectra are shown in Figs. 2 to 5 in correspondence with the example numbers. (The following is a blank space) (Example 6) C. 71.32%, H, 4.91%; N,
Good agreement was shown at 7.24%. (Example 7) 20.3 g (0.1
mole). 3.3゜-diaminodiphenyl sulfo:/
12.4g (0.05mol). Synthesis was carried out in the same manner as in Example 1, except that 13.3 g (0.1 mol) of m-isobropenylaniline was used. m. of the synthesized aromatic polyamide oligomer having unsaturated end groups. p. is 125
~135℃. The infrared absorption spectrum of this product is shown in FIG.

The elemental analysis value is C. 71.51%: H. 5. [+3%: N. 7
-0! The theoretical value of l96te is 20.3g (0.1g) of isophthalic acid chloride as raw material.
mol), dianisidine 21.3EB (0.0875 mol), m-isobropenylaniline 3.25g (0.0
Synthesis was carried out in the same manner as in Example 1, except that 25 mol) was used. m. of the synthesized aromatic polyamide oligomer having unsaturated end groups. p. is 145-160°C, and the infrared absorption spectrum of this product is shown in Figure 7. The elemental analysis value is C. 71.73%: H, 5.01% 2 N.
The theoretical value is C. 71.67%;H. 4.98%2N. showed good agreement. (Example 8) 20.3 g (0.1 mol) of 7.43% isofucuric acid chloride at 7.38%
．． 2.4-: 2.6-mixed toluylene diamine (80:20) 10.17 g (0.083 mol), p
The same operation as in Example 1 was carried out except that 97 g (0.033 mol) of -aminostyrene was used. The m.p. of the synthesized aromatic polyamide oligomer having unsaturated end groups was 190 to 205°C The infrared absorption spectrum of this product is shown in FIG.

The elemental analysis value is C. 73.11%: H. 4.95%
．． N. l b. The theoretical value at 21% is C. 72.97%. H, 4.91%: N. 1
Good agreement was shown at 0.32%. [Effect J Since conventional aromatic polyamides were thermoplastic resins,
Although it had excellent properties such as chemical resistance and electrical properties, its strength at high temperatures decreased significantly, limiting its field of use. The present invention improves these drawbacks and develops an aromatic polyamide oligomer having a novel terminal unsaturated group that can be used as a raw material for a thermosetting aromatic polyamide with excellent processability, although it is the same aromatic polyamide. It was very successful. This oligomer can be synthesized at low temperatures, and although it has a polymerizable double bond, it is relatively stable, does not gel during the molding process, and can be easily cured by the action of a radical-generating catalyst. It is something that has properties. The aromatic polyamide obtained by curing this oligomer has excellent heat resistance and does not lose strength even at high temperatures.

[Brief explanation of drawings]

1 to 8 are infrared absorption spectra of aromatic polyamide oligomers produced in corresponding Examples 1 to 8, respectively.

Claims (2)

[Claims] (1) General formula ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ [However, in the formula, A and A' are radically polymerizable unsaturated groups (
A=A′), R is a hydrogen atom or a lower alkyl group,
R_1 and R_2 are divalent aromatic groups, and n is any numerical value from 1 to 15. An aromatic polyamide oligomer having a terminal unsaturated group represented by: (2) A method for producing an aromatic polyamide oligomer having a terminal unsaturated group, which comprises reacting an aromatic diamine, an aromatic monoamine having a terminal unsaturated group, and an aromatic dicarboxylic acid dihalide in the presence of a hydrogen halide acceptor. .