JPH02218711A - Aromatic polyamide oligomer having thermal unsaturated group and production thereof - Google Patents

Abstract

PURPOSE:To obtain the subject oligomer useful as a raw material for thermosetting aromatic polyamides excellent in processability by reacting an aromatic diamine with thermal unsaturated group-containing aliphatic monoamine and aromatic dicarboxylic acid dihalide in the presence of a hydrogen halide acceptor. CONSTITUTION:The objective oligomer, obtained by reacting (A) an aromatic diamine (e.g. m-phenylenediamine) with (B) an aliphatic monoamine having terminal unsaturated group (preferably allylamine) and (C) an aromatic dicarboxylic acid dihalide (preferably isophthaloyl dichloride) in the presence of a hydrogen halide acceptor and having the terminal unsaturated groups expressed by the formula (A is radically polymerizable unsaturated group; R is H or lower alkyl; R1 and R2 are bifunctional aromatic group; n is 1-15).

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of use in the industry] The present invention relates to an oligomer useful as a heat-resistant synthetic resin, particularly a heat-resistant aromatic polyamide with improved 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 used in fields that require heat resistance, such as laminates, laminates, and adhesives, to expand the market, and to expand into broad new fields with new functions.

In response to these demands, a group of synthetic resins called engineering plastics, such as aromatic polyamides, polyimides, polysulfones, and polyphenylene oxides, 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 polymetaphenylene isophthalamide (product name:
Nomex or HT-1) is a typical type.

All of these polyamides are classified as thermoplastic synthetic resins, and polyamides that thermoset oligomers have not yet been found.

For this reason, 1. Although it has a higher melting point than ordinary 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 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] 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] The present inventors found that when molding the material as a molding material or as a laminate, it has a relatively low melting point and can be molded into a desired shape under heat and pressure. In order to obtain an aromatic polyamide that can be cured under moderate conditions and has sufficient heat resistance, mechanical strength, chemical stability, etc. after curing,
Aromatic diamines, aliphatic monoamines with terminal unsaturated groups, and aromatic dicarboxylic acid dihalides are mixed with halogenated water (
is reacted in the presence of a receptor to form an unsaturated polyamide oligomer having a terminal unsaturated group represented by the general formula, which can be cured in the presence of a radical generating catalyst ( It was discovered that polyamide has the above-mentioned excellent properties, and the present invention was completed.

The aromatic polyamide oligomer having a terminal unsaturated group according to the present invention can be illustrated by the following reaction formula.

(Left below) (77 Aromatic dicarboxylic acid dihalide) ■ (Aromatic polyamide oligomer) In order for the reaction to proceed smoothly, a receptor for hydrogen chloride during excavation is essential. It is convenient to use grade amines or caustic.

In this case, a value of n from 1 to 15, preferably from 3 to 7, is advantageous from the viewpoint of ease of moldability, and polymerization at this stage is not particularly necessary.
into the aqueous phase and acid chloride into an inert organic solvent that does not dissolve in water to perform an interfacial polycondensation reaction, or dissolve both in an inert organic solvent and condense at a low temperature to perform a low-temperature liquid polycondensation reaction. This can be done by

Aromatic diamines that can be used in the present invention include:

For example, metaphenylenediamine, 4.4'/3.373
．． 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
'-diaminodiphenylsulfone, dianisidine, 2.
4-toluylene diamine, a 2.4/2.6-1-ylene diamine mixture, etc. can be used, and two or more types can also be used as a mixture.

Examples of aliphatic monoamines having a terminal unsaturated group include allylamine, diallylamine, methalylamine, allylmethylamine, l-amino-4-pentene, etc., and the ability to synthesize terminally unsaturated polyamide oligomers at low temperatures; Allylamine is most commonly used in terms of stability, availability, price, etc. of the polyamide oligomer produced. 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 or the like that binds to the hydrogen halide at the same time. becomes.

Hereinafter, the aliphatic amine having a terminal unsaturated group will be explained using allylamine 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 thereof include terephthalic acid dichloride, isophthalic acid dichloride, and phthalic acid dichloride.

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 melting point of the resulting aromatic polyamide is high). Therefore, isophthalic acid dichloride best meets the purpose of the present invention.

Since this synthesis reaction proceeds relatively stoichiometrically, rl in the above formula [I] was calculated.2. Required amounts of aliphatic monoamine, aromatic diamine, and aromatic dicarboxylic acid dihalide were reacted. If precise adjustment is required, the molar ratio can be determined by repeated tests. It is possible,
It can be molded at temperatures below 200°C.

The aromatic polyamide oligomer having unsaturated end groups 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 generation catalyst, but from an engineering point of view, the bar oyaside type is suitable, 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 dosage is 1 to 3 phr.

In addition, the combined use of an unsaturated bond and a copolymerizable monomer is possible when the monomer dissolves an aromatic polyamide oligomer, and the range of application is particularly wide when n in formula I1 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 cured aromatic polyamide. It is necessary to do so.

It goes without saying that the aromatic polyamide oligomer having unsaturated terminal groups according to the present invention can be used in combination with reinforcing agents, fillers, +1t=q agents, colorants, other polymers as low-shrinkage agents, etc., as necessary.

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

[Example] (Example 1) 20.3 g (0.1 mol) of isophthalic acid dichloride and dimethylform were placed in a 1β four-neck separable flask equipped with a reflux condenser, dropping funnel, thermometer, and stirrer. Charge 100 g of amide (DMF) and cool to below 10°C.

Next, 8.1 g (0°075 mol) of mekufuenylenediamine, 15.15 g (0.075 mol) of triethylamine,
Weigh 75g of DMF fil R! , .

Pour into a separable flask. Next, allylamine 2
．． 85g (0.05 mol), triethylamine 5.0
5 g (0.05 mol) and 25 g of DMF were weighed and mixed and added dropwise to a separable flask.

During this time, the temperature of the reaction mixture is kept below 10°C.

After the dropwise addition was completed, the temperature of the reaction mixture was kept below 10°C, and
hr, continue stirring #1.

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

m, p, 260° C. or higher, the infrared absorption spectrum of this product is shown in FIG.

What is the elemental analysis value?

C, 70,: 12%, [1, 4, 67%, N, 1
The theoretical value is 1.67%.

C, 70, 15%, H, 4, 8t1%, N, 11
．． It showed a good value of 69%.

(Examples 2 to 8) General formula 11. N-R-NH! An aromatic polyamide oligomer having an unsaturated terminal group was synthesized by the same procedure as in Example I except that [i'l and n of R of the aromatic diamine compound represented by were changed.

Table 2: The aromatic polyamide oligomer having an unsaturated end group synthesized with an acid compound has the following table. Moreover, those infrared absorption spectra are shown in FIGS. 2 to 8 in correspondence with the example numbers.

(Reference example) In Example 7 (also aromatic polyamide oligomer 1ffl
m parts, dicumyl peroxide (2% acetone solution)
Add a portion of lffi to a test tube and gradually warm to ambient temperature.

Remove the acetone, dry and heat to 200℃,
After curing for 7 hours, an amber-colored, durable, insoluble and infusible bulk polymer was obtained. When the obtained polymer was crushed in a mortar and thermogravimetrically analyzed in air at a boundary temperature rate of IO℃/min, no change occurred at all up to 350℃, and at 450℃ the weight decreased by about 8%. The loss was recognized.

[Effects] Conventional aromatic polyamides were thermoplastic resins, so
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 creates an aromatic polyamide oligomer having a novel terminal unsaturated group that can be used as a raw material for thermosetting aromatic polyamide with excellent processability, although it is the same aromatic polyamide. succeeded in developing it.

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 the drawing]

1 to 8 are infrared absorption spectra diagrams corresponding to the example numbers of the aromatic polyamide oligomers obtained in Examples 1 to 8 of the present invention. Santo Tsunen Book 1 I Orthographic version March 30, 1989

Claims (2)

[Claims] (1) General formula ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ [However, in the formula, A is a radically polymerizable unsaturated group, R is a hydrogen atom or a lower alkyl group, R_1 and R_2 are divalent aromatic groups, 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 aliphatic monoamine having a terminal unsaturated group, and an aromatic dicarboxylic acid dihalide in the presence of a hydrogen halide acceptor. .