JPH0667889B2 - Unsaturated group-containing aromatic polyamide oligomer and method for producing the same - Google Patents

Description

TECHNICAL FIELD The present invention relates to an oligomer useful as a raw material for a heat-resistant synthetic resin, particularly a heat-resistant aromatic polyamide having a thermosetting property, and a method for producing the oligomer.

[Prior Art] As the demand for the plastics industry has become more sophisticated, industrial materials with special properties have become necessary, and this tendency is rapidly expanding in conjunction with the sophistication of the industrial sector.

The demands for improved heat resistance include plastics, films, fibers,
This is also to impart heat resistance to industrial materials in the fields where heat resistance is required, such as laminates, laminates and adhesives, to expand the market and to expand into new fields with new functions.

In response to such demand, a group of synthetic resins called engineering plastics such as aromatic polyamide, polyimide, polyfluphone, polyphenylene oxide, etc. have already been developed, and industrial production as a plastic having a new function different from conventional synthetic resins. Aromatic polyamide known under the name of aramid is one of them.

As aromatic polyamides, polyparaphenylene terephthalamide (trade name: Kepler) and polymetaphenylene isophthalamide (trade name: developed by Du Pont).
Nomex or HT-1) is a typical type.

All of these polyamides are essentially classified as thermoplastic synthetic resins, but generally have a high melting point, and some have a small difference between the melting point and the thermal decomposition temperature or they are reversed. Therefore, there is a problem that melt molding is difficult or impossible depending on the structure. On the other hand, polyamides of the type that prepares an oligomer as a precursor and heat-cures it have not been proposed yet.

The reason why there was no thermosetting aromatic polyamide was
It is considered that its melting point was generally sufficiently higher than that of conventional thermoplastic synthetic resins, and that it was judged that the introduction of unsaturated bonds had a large risk of causing undesirable gelation during the molding process.

[Problems to be Solved by the Invention] Aromatic polyamide is a heat-resistant polymer that is relatively stable even at a considerably high temperature, has excellent electrical properties and mechanical strength, and has high chemical stability. .

The present invention aims to develop a raw material for producing an aromatic polyamide having improved molding processability without losing the excellent properties of these conventional polyamides, and further improved mechanical strength and chemical stability at high temperature. It is what

[Means for Solving the Problem] The present inventors have a relatively low melting point when molding as a molding material or a laminated plate, and can be molded into a desired shape under heating and pressurization. In order to obtain an aromatic polyamide having sufficient heat resistance, mechanical strength, and chemical stability after curing, it is possible to cure the aromatic diamine, aromatic dicarboxylic acid dihalide and unsaturated alcohol or unsaturated alcohol. Saturated phenol is reacted in the presence of a hydrogen halide acceptor to give a compound of the general formula An unsaturated polyamide oligomer having a polymerizable unsaturated group represented by was obtained.

This compound can be cured in the presence of a radical generating catalyst, and it was found that this cured aromatic polyamide has the above-mentioned excellent properties, and the present invention has been completed.

The aromatic polyamide oligomer having an unsaturated group of the present invention can be synthesized by the following reaction formula as an example.

In order to allow the above reaction to proceed smoothly, an acceptor of hydrogen chloride produced as a by-product is required, and it is generally convenient to use a tertiary amine or caustic.

In this case, an oligomer having n of 1 to 15, preferably about 3 to 7, is advantageous in terms of moldability and is not required to be polymerized at this stage. This reaction is generally carried out by mixing amines in an aqueous phase and acid chloride in an inert organic solvent insoluble in water to carry out an interfacial polycondensation reaction,
Alternatively, it can be carried out by a low temperature solution polycondensation reaction in which both are dissolved in an inert organic solvent and condensed at a low temperature.

Examples of the aromatic diamine 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'-diaminodiphenyl sulfone, 4,
4'-diaminodiphenyl sulfone, dianisidine, 2,4
-Toluylenediamine, 2,4 / 2,6-toluylenediamine mixture, 1,3-bis (3-aminophenoxy) benzene and the like can be used, and a mixture of two or more kinds can also be used.

As a precursor of an organic residue having a polymerizable unsaturated group at the terminal or inside of the terminal chain, allyl alcohol, crotyl alcohol, methyl vinyl carbinol, propargyl alcohol, 2-butyn-1-ol, 3-butyne -2-ol, 3-butyn-1-ol, 5-norbornene-2
-Methanol, cinnamyl alcohol, o-, m- or p-isopropenylphenol, o-, m- or p-
Vinylphenol etc. are mentioned.

Further, as the aromatic dicarboxylic acid dihalide that can be used in the present invention, a dichloride of an aromatic dibasic acid is convenient, and typical examples thereof include terephthalic acid dichloride, isophthalic acid dichloride, phthalic acid dichloride and mixtures thereof.

Aromatic polyamides derived from phthalic acid dichloride have a little insufficient heat resistance, and when terephthalic acid dichloride is used, the heat resistance of the polymer after thermosetting is sufficient, but the aromatics obtained as precursors. The melting point of the group polyamide oligomer tends to be high and the handling tends to be difficult. From a practical point of view, isophthalic acid dichloride has the best balanced property, which is consistent with the object of the present invention.

Since this synthetic reaction proceeds in a relatively stoichiometric manner, a desired value is put into n in the above formula [A] to calculate (the calculation may be the same even if it is not allyl alcohol), and it is necessary. Amounts of unsaturated alcohols or unsaturated phenols, aromatic diamines and aromatic dicarboxylic acid dihalides may be reacted, and if precise adjustments are required, the molar ratio can be determined by a simple test.

As described above, the composition of the aromatic polyamide oligomer obtained by this reaction can be easily selected, and the aromatic polyamide oligomer can be easily molded at a temperature of 200 ° C. or lower.

The aromatic polyamide oligomer having an unsaturated group synthesized according to the present invention can be cured by the combined use of a radical generating catalyst, and the heat resistance can be markedly improved.

The radical generating catalyst does not need to be limited, but the peroxide type is industrially suitable, and the molding temperature is 1
When the temperature is 00 ° C. or higher, a so-called high-temperature decomposition type, for example, dicumyl peroxide type is used.

Appropriate amount of use is 1 to 3 phr.

Also, the combined use of the unsaturated bond of the oligomer of the present invention and the copolymerizable monomer is possible when the monomer dissolves the aromatic polyamide oligomer, and particularly when n in the formula [A] is a small value, Flexible. The combined use of monomers promotes softening of the entire condensation system and improves moldability and workability, but on the other hand, it tends to reduce the heat resistance of the cured aromatic polyamide, so the amount added should be adjusted according to the purpose. is necessary.

In the production of a molded article using the aromatic polyamide oligomer having an unsaturated group according to the present invention, a reinforcing agent, a filler, a release agent, a colorant, and other polymers as a low-shrinking agent can be used in combination as necessary. Of course.

Next, in order to help understanding of the present invention, examples will be shown below.

[Example] (Example 1) 500 equipped with reflux condenser, dropping funnel, thermometer, stirrer
20.3 g (0.1 mol) of isophthalic acid chloride and 100 g of dimethylformamide (DMF) are charged into a 4-necked separable flask of m and cooled to 10 ° C or lower.

Next, 1.94 g (0.033 mol) of allyl alcohol,
3,4'-diaminodiphenyl ether (3,4'-DAP
16.67 g (0.0834 mol) of E), 20.5 g (0.203 mol) of triethylamine and 80 g of DMF are weighed and mixed and added dropwise to the reaction flask. During that time, the reaction temperature is kept below 10 ° C.

After completion of the dropping, the dropping funnel is washed with 20 g of DMF, and the washing solution is added to the reaction flask.

Further, while maintaining the temperature of the reaction mixture at 10 ° C. or lower, stirring is continued for 2 hours.

Next, the reaction mixture is gradually added to a large amount of water with vigorous stirring to precipitate crystals. The precipitated crystals are suction filtered, washed with water and dried.

m. p. The infrared absorption spectrum of this substance is shown in FIG.

Elemental analysis values were C, 72.34%; H, 4.39%; N, 7.25%, and theoretical values were in good agreement with C, 72.15%; H, 4.43%; N, 7.38%.

(Example 2) 500 equipped with reflux condenser, dropping funnel, thermometer, stirrer
Into a 4-necked separable flask of m, 20.3 g (0.1 mol) of isophthalic acid chloride and 100 g of DMF are charged and cooled to 10 ° C or lower.

Next, 2.4 g (0.0333 mol) of crotyl alcohol, 16.67 g (0.0834 mol) of 3,4′-DAPE, 20.5 g (0.203 mol) of triethylamine, and 80 g of DMF were weighed and mixed, and then mixed in a reaction flask. Drop it. Meanwhile, the reaction temperature is maintained at 10 ° C. or lower.

After completion of the dropping, the dropping funnel is washed with 20 g of DMF, and the washing solution is added to the reaction flask.

Further, while maintaining the temperature of the reaction mixture at 10 ° C. or lower, stirring is continued for 2 hours.

Next, the reaction mixture is gradually added to a large amount of water with vigorous stirring to precipitate crystals. The precipitated crystals are suction filtered, washed with water and dried.

m. p. The infrared absorption spectrum of this product is shown in FIG.

Elemental analysis values were C, 72.47%; H, 4.52%; N, 7.19%, and theoretical values were in good agreement with C, 72.35%; H, 4.57%; N, 7.28%.

(Example 3) Instead of 1.94 g (0.0334 mol) of allyl alcohol, 1.87 g (0.033) of propargyl alcohol.
The same operation as in Example 1 was performed except that 4 mol) was used.

m. p. The infrared absorption spectrum of this product is shown in FIG.

Elemental analysis values were C, 72.48%; H, 4.19%; N, 7.23%, and theoretical values were in good agreement with C, 72.30%; H, 4.23%; N, 7.40%.

(Example 4) 5-Norbornene-2-methanol 4.14 g instead of 1.94 g (0.0334 mol) of allyl alcohol
The same operation as in Example 1 was performed except that (0.0334 mol) was used.

m. p. The infrared absorption spectrum of this product is shown in FIG.

Elemental analysis values were C, 72.42%; H, 4.71%; N, 6.82%, and theoretical values were in good agreement with C, 72.37%; H, 4.73%; N, 6.90%.

(Example 5) Instead of 1.94 g (0.0334 mol) of allyl alcohol, 4.47 g of m-isopropenylphenol (0.
The same operation as in Example 1 was carried out except that 0334 mol) was used.

m. p. The infrared absorption spectrum of this product is shown in FIG.

The elemental analysis values were C, 74.02%; H, 4.43%; N, 6.68%, and the theoretical values were in good agreement with C, 73.83%; H, 4.49%; N, 6.84%.

(Example 6) 3,4'-DAPE 16.67 g (0.0834 mol) instead of 3,3'-diaminodiphenyl sulfone 20.6
The same operation as in Example 1 was performed except that 7 g (0.0833 mol) was used.

m. p. The infrared absorption spectrum of this product at 140 to 155 ° C. is shown in FIG.

Elemental analysis values were C, 64.23%; H, 3.91%; N, 6.36%, and theoretical values were in good agreement with C, 64.04%; H, 3.93%; N, 6.55%.

[Effect of the Invention] Although the conventional aromatic polyamide is a thermoplastic resin,
Since it has a high melting point, chemical resistance has excellent properties such as electrical characteristics, but it has drawbacks in moldability and the mechanical strength at high temperatures is greatly reduced, resulting in a melting point or decomposition point. Even in the following temperatures, the field of use was limited. The present invention solves these drawbacks and is a novel unsaturated compound which can be used as a raw material for a thermosetting aromatic polyamide, which is the same aromatic polyamide but has excellent moldability and has little decrease in mechanical strength even at high temperatures. We have succeeded in developing an aromatic polyamide oligomer having a group.

Although this oligomer can be synthesized at low temperature and has a double bond that can be polymerized, it is relatively stable and does not gel during the molding process. It has an excellent property that it can be hardened to.

The aromatic polyamide obtained by curing this oligomer is an aromatic polyamide having excellent heat resistance that does not cause a decrease in strength even at high temperatures.

[Brief description of drawings]

1 to 6 are infrared absorption spectrum diagrams of unsaturated group-containing aromatic polyamide oligomers obtained in Examples 1 to 6, respectively.

Claims (4)

[Claims] 1. A general formula An unsaturated group-containing aromatic polyamide oligomer represented by: 2. The unsaturated according to claim 1, which comprises reacting an aromatic diamine, an aromatic dicarboxylic acid dihalide and a polymerizable unsaturated alcohol or a polymerizable unsaturated phenol in the presence of a hydrogen halide acceptor. Process for producing group-containing aromatic polyamide oligomer. 3. The unsaturated alcohol according to claim 2, wherein the unsaturated alcohol is an unsaturated residue having an organic residue having a polymerizable double bond or a triple bond at the terminal or inside of the carbon chain or an aromatic unsaturated group. A method for producing a saturated group-containing aromatic polyamide oligomer. 4. The method for producing an unsaturated group-containing aromatic polyamide oligomer according to claim 2, wherein the unsaturated phenol is at least one of vinylphenol and isopropenylphenol.