JPH0350219A - Polymerizable unsaturated group-terminated aromatic polyamide oligomer and its production - Google Patents

Abstract

PURPOSE:To obtain the title oligomer which can be used as a starting material for a thermosetting aromatic polyamide of excellent moldability by reacting an aromatic diamine with an internally unsaturated organic acid halide and an aromatic dicarboxylic acid dihalide in the presence of a hydrogen halide acceptor. CONSTITUTION:An aromatic diamine (e.g. m-phenylenediamine) is reacted with an internally unsaturated organic acid halide (e.g. crotonoyl chloride) and an aromatic dicarboxylic acid dihalide (e.g. isophthaloyl chloride) in the presence of a hydrogen halide to produce the title oligomer of formula I [wherein A and A' are each an organic residue having a radical-polymerizable internal unsaturation (A and A' may be the same); B and B' are each a bivalent group of CO or SO2; R and R' are each a bivalent aromatic group; and (n) is 1-15] (e.g. an oligomer of formula II). This oligomer can be cured in the presence of a radical generation catalyst, and the cured aromatic polyamide is increased in mechanical strengths and chemical stability at high temperatures.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application J] The present invention relates to an oligomer 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,
The aim is 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, boimide, polysulfone, and polyphenylene oxide, have already been developed and are now being industrialized as plastics with new functions different from conventional synthetic resins. Aromatic polyamides, known under the name aramid, are one of them, and are now being produced and opening up new areas of demand.

Examples of aromatic polyamides include polyparaphenylene terephthalamide (product name: Kevlar) and polymethaphenylene isophthalamide (product name:
Nomex or HT-1) is a typical type.

All of these polyamides are classified as thermoplastic synthetic resins, and they generally have a high melting point, and the difference between the melting point and the thermal decomposition temperature is small, so melt molding is difficult or impossible depending on the structure. there were. On the other hand, a type of polyamide that thermosets oligomers has not yet been found.

The reason why there was no thermosetting aromatic polyamide was as follows.
- This is thought to be because the melting point of the thermoplastic synthetic resin was sufficiently 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 1 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 present invention aims to further improve mechanical strength and chemical stability at high temperatures without losing these properties.

[Means for Solving the Problems] When the present inventors mold the material as a molding material or as a laminate, the melting point is relatively low.

In order to obtain an aromatic polyamide that can be molded into a desired shape under heat and pressure, can be cured under relatively mild conditions, and has sufficient heat resistance, mechanical strength, chemical stability, etc. after curing. An aromatic diamine, an organic acid halide having an internally 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 an internally unsaturated group represented by the general formula. It was 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 polymerizable unsaturated group of the present invention can be synthesized by, for example, the following reaction formula.

Isophthalic acid dichloride (aromatic dicarboxylic acid dihalide) (aromatic polyamide oligomer) In order for the reaction to proceed smoothly, an acceptor for the by-product hydrogen chloride is required. It is convenient to use.

In this case, a value of n of about 1 to 15, preferably about 3 to 7, is advantageous for ease of moldability.

Polymerization at this stage is not particularly necessary; this reaction is generally carried out by mixing amines in an aqueous phase and acid chloride in an inert organic solvent that does not dissolve in water, and performing an interfacial polycondensation reaction, or by combining both. This can be carried out by a low-temperature solution polycondensation reaction in which the mixture is dissolved in an inert organic solvent and condensed at a low temperature.

Examples of aromatic diamines that can be used in the present invention include metaphenylenediamine, 4.4°-diaminodiphenylmethane, 4,4′-diaminodiphenylpropane, 3
．． 3'-dimethyl-4,4'-diaminodiphenylmethane, 4.4'-diaminodiphenyl ether, 3.4'
-diaminodiphenyl ether, 3.3°-diaminodiphenylsulfone, 4,4′-diaminodiphenylsulfone, dianisidine, 2,4-tolylenediamine,
2.4/2.6- Toluylene diamine mixture, 1.3
-bis(3-aminophenoxy)benzene, etc. can be used, and two or more types can be used in combination.

Organic acid halides, such as crotonic acid chloride and styryl, are useful precursors for obtaining organic residues having internally unsaturated groups (meaning that the polymerizable unsaturated bond is located within the molecular chain rather than at the end). Examples include acetyl chloride, β-styrenesulfonyl chloride, cinnamic acid chloride, and sorbic acid chloride, but crotonic acid chloride is most commonly used in terms of availability, price, etc.

Hereinafter, the organic acid halide having an internally unsaturated group will be explained using crotonic acid chloride as a representative.

Further, as the aromatic dicarboxylic acid dihalide that can be used in the present invention, dichlorides of aromatic dibasic acids are convenient, and representative examples include terephthalic acid dichloride, isophthalic acid dichloride, phthalic acid dichloride, and mixtures thereof.

From a practical point of view, phthalic acid dichloride produces aromatic polyamides with insufficient heat resistance, and when terephthalic acid dichloride is used, the heat resistance is sufficient, but the resulting aromatic polyamide has a high melting point. Therefore, isophthalic acid dichloride best meets the purpose of the present invention.

This synthesis reaction proceeds relatively chemically, so after calculating n in the above formula II, the necessary amounts of internally unsaturated organic acid halide, 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 can be molded at a temperature of 200° C. or lower.

The aromatic polyamide oligomer having an internally unsaturated group synthesized according to the present invention can be cured in combination with a radical generating catalyst, making it possible to significantly improve heat resistance.

There is no need to limit the radical generating catalyst, but peroxide type is suitable industrially, and the molding temperature is 1.
When the temperature is 00° C. or higher, a so-called high-temperature decomposition type, for example a dicumyl peroxide type, is used.

The appropriate amount to use is 1 to 3 phr.

In addition, the combined use of a monomer copolymerizable with an unsaturated bond is possible when the monomer dissolves the aromatic polyamide oligomer. The combined use of Zimmer promotes the softening of the entire condensation system and improves JFε formation properties and workability, but tends to lower the heat resistance of the cured aromatic polyamide.

It is necessary to adjust the amount added according to the purpose.

It goes without saying that the aromatic polyamide oligomer having an internally unsaturated group according to the present invention can be used in combination with reinforcing agents, fillers, other polymers as WI type pre-colorants, low shrinkage agents, etc., if necessary.

Next, examples will be shown below to help understand the present invention.

[Example j (Example I) IJ2 equipped with reflux condenser, dropping funnel, thermometer, stirrer
16.92 g (0,083-1 nyl) isophthalic acid dichloride and g dimethylformamide were placed in a four-necked separable flask and cooled to below 10°C.

Next, 3.4′-diaminodiphenyl ether (3.4.

-DAPE) 20g ((L 1 mol), triethylamine 20.2g (0.2 mol), and DMF 75g are weighed and mixed and added dropwise to a separable flask.

Subsequently, 3.483 g (0.03 g) of crotonic acid chloride
3 moles) and 25 g of DMF were weighed and mixed and added dropwise to a separable flask. During this time, keep the temperature of the reaction mixture below 10°C. i1! After i, the temperature of the reaction mixture was lowered to 10
Keep it below ℃ for 2 hours. lj! Continue stirring.

Next, the reaction mixture is 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. The infrared absorption spectrum of this product at 165 to 180°C is shown in FIG.

The elemental analysis value is C. 72.68%;H. 4.57%. N. 8
．． The theoretical value at 31% is C. 72.51%: H. 4.53%: N. 8
．． Good agreement was shown at 46%.

Isophthalic acid chloride 10.15g (o.

05 mol), 3.3'-diaminodiphenylsulfone 16.53 g (0.067 mol), triethylamine 1: 3.6 g (0.135 mol), and crotonic acid chloride 3.483 g (0.033 mol) were used. The other operations were the same as in Example 1.

m. The infrared absorption spectrum of this product is shown in FIG. 2 at p, l4'5 to 160°C.

Elemental analysis values are: C, 63.26%: H, 4.12%: N. 7.3
The theoretical value is 2%.

C. 63.24%: H. 4.08%, N, 7
．． Good agreement was shown at 38%.

(Example 3) Isophthalic acid chloride 10.15g (0.

05 mol), mixed toluylene diamine (2.4-toluylene diamine/2.6-1-ylene diamine [80
:201) 12.2g (0.1 mol), triethylamine 20.2g (0.2 mol), and crotonic acid chloride 10.45g (0.1 mol) were used, but the same operation as in Example 1 was performed. .

m. p. The infrared absorption spectrum of this product at 170 to 185°C is shown in FIG.

What is the elemental analysis value?

C, 70.73%:)], 5.89%; 10
．． The theoretical value at 82% is C. 70.59%: H. 5.811%: N, 10
．． Good agreement was shown at 98%.

[Effects] Conventional aromatic polyamides are thermoplastic resins, so they have good chemical resistance. ! Although it had excellent properties such as mechanical properties, it had problems with moldability, which limited its field of use. The present invention improves these drawbacks and develops an aromatic polyamide oligomer having a novel internal unsaturated group that can be used as a raw material for a thermosetting aromatic polyamide with excellent moldability, 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 is an aromatic polyamide with excellent heat resistance that does not cause a decrease in strength even at high temperatures.

[Brief explanation of drawings]

1 to 3 show infrared absorption spectra of the aromatic polyamide oligomers obtained in Examples 1 to 3.

Claims (4)

[Claims] (1) General formula ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ [However, in the formula, A and A' are organic residues having internal unsaturated groups capable of radical polymerization (A = A' is also possible), B, B ′ is −
CO- or -SO_2-, R_1, and R_2 represent a divalent aromatic group, and n is any numerical value from 1 to 15. ] An aromatic polyamide oligomer having a polymerizable unsaturated group represented by: (2) Production of an aromatic polyamide oligomer having a polymerizable unsaturated group by reacting an aromatic diamine, an organic acid halide having an internal unsaturated group, and an aromatic dicarboxylic acid dihalide in the presence of a hydrogen halide acceptor Method. (3) A and A' in the general formula described in claim 1 are CH_
An aromatic polyamide oligomer in which 3CH=CH-, B, and B' are represented by -CO-. (4) A method for producing an aromatic polyamide oligomer having a polymerizable unsaturated group, which comprises reacting an aromatic diamine, crotonic acid chloride, and aromatic dicarboxylic acid dihalide in the presence of a hydrogen halide acceptor.