JPH04132733A - Unsaturated group-containing aromatic polyamide oligomer and production thereof - Google Patents

Abstract

PURPOSE:To obtain the subject polymerizable oligomer useful as a raw material of a heat-resistant aromatic polyamide by reacting a bifunctional amine having unsaturated bond with an aromatic dicarboxylic acid dihalide in the presence of a hydrogen halide acceptor. CONSTITUTION:For instance, a bifunctional amine having unsaturated bond derived from a condensate of an aromatic polyamine and an unsaturated carboxylic acid chloride, bifunctional amine having unsaturated bond derived from an adduct of an aromatic polyamine and an unsaturated cyclic carboxylic acid anhydride or a mixture of said amines is reacted with an aromatic dicarboxylic acid dihalide in the presence of a hydrogen halide acceptor to afford the aimed oligomer having unsaturated groups polymerizable with side chain expressed by the formula (R1 is bifunctional aromatic group; R2 is aromatic residue induced from polyfunctional aromatic polyamine having at least three functions; A is residue induced from polymerizable aliphatic or aromatic unsaturated carboxylic acid bonded to aromatic polyamine with amide bonding; n is 0-15).

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application 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 imparted with thermosetting properties, and a method for producing the oligomer.

[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 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 aramids, are being produced and are developing new demand areas, one of which is aromatic polyamides, known under the name aramids.

Examples of aromatic polyamides include polyparaphenylene terephthalamide (product name: Kevlar) and polymetaphenylene isophthalamide (product name:
Nomex or HTl) is a typical type.

All of these polyamides are essentially classified as thermoplastic synthetic resins, but they generally have a high melting point;
Moreover, because the difference between the melting point and the thermal decomposition temperature is small, or even reversed in some cases, melt molding is difficult or impossible depending on the structure. On the other hand,
A type of polyamide in which an oligomer is prepared as a precursor and then thermally cured has not yet been proposed.

The reason why there was no thermosetting aromatic polyamide was as follows.
- This is thought to be due to the fact that its melting point was statistically 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. It will be done.

[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 develop raw materials for producing aromatic polyamides that have improved moldability without losing the excellent properties of these conventional polyamides, as well as improved mechanical strength and chemical stability at high temperatures. That is.

[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 mild conditions and has sufficient heat resistance, mechanical strength, and chemical stability after curing, aromatic dicarboxylic acid dihalide, aromatic polyamine, and unsaturated carboxylic acid are used. Halogenating a divalent amine having an unsaturated bond consisting of a condensate with chloride, a divalent amine having an unsaturated bond consisting of an adduct of an aromatic polyamine and an unsaturated cyclic carboxylic acid anhydride, or a mixture thereof. Reacted in the presence of a hydrogen acceptor, novomers with the general formula % can be synthesized by the following reaction scheme - by way of example.

First step: Synthesis of divalent amine with unsaturated bonds
[A polymerizable unsaturated group-containing polyamide oligomer represented by I was obtained.

It was discovered that this material 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.

Aromatic polyamide (hereinafter referred to as blank space) having an unsaturated group of the present invention CH.

? A divalent amine having an unsaturated bond whose main component is CH2=C-C=0...
...[TII] Second step, synthesis of unsaturated group-containing aromatic polyamide oligomer (n+2) ．． C+ has =n, n=o ~ 15, and structure [X] and structure [Y] have 2 to the first stage unsaturated bond.
The production rate of the amines is the same, and the bonding order is random.

In order to make the above reaction proceed smoothly, an acceptor for the by-produced hydrogen chloride is required, and it is convenient to use a tertiary amine or a caustic alkali.

In this case, oligomers with an average degree of polymerization in which n is about 0 to 15, preferably about 3 to 7, are advantageous because of their ease of moldability, and polymerization at this stage is not necessary at all.This reaction is generally carried out using amines. into the aqueous phase and the acid chloride into an inert organic solvent that does not dissolve in water to perform an interfacial polycondensation reaction, or by a low-temperature solution polycondensation reaction in which both are dissolved in an inert organic solvent and condensed at a low temperature. can be done.

The divalent amine having an unsaturated bond that can be used in the present invention can be produced by the following condensation reaction between an aromatic polyamine and an unsaturated carboxylic acid chloride or an addition reaction between an aromatic polyamine and an unsaturated cyclic carboxylic acid anhydride. Examples include synthetic ones. The aromatic polyamine which is one component used when synthesizing a divalent amine having an unsaturated bond is a phenylene group, an alkyl-substituted phenylene group, a diphenylene group, a diphenyl ether group, or a naphthylenyl group R3, a halogen atom, Represents a hydroxyl group, a lower alkoxy group having 4 or less carbon atoms, or a lower alkyl group having 5 or less carbon atoms, and R3 may be the same or different from each other and may form a ring 61:1 or 2 m:0 an integer of 0 to 10, preferably 0 to 3, or sulfuric acid chloride, cinnamic acid chloride, crotonic acid chloride, or an aromatic group represented by (R,:H or CH, α is the same as above) Examples include polyamines.

Examples of the unsaturated carboxylic acid chloride which is the other component include acrylic acid chloride and methacrylate (R is H or CH3).

The reaction ratio of the aromatic polyamine and the unsaturated carboxylic acid chloride may be such that at least two amines remain in one molecule. That is, when an m-valent polyvalent amine is used, it is sufficient to react with (m-2) moles or less of monovalent unsaturated carboxylic acid chloride.

As the unsaturated cyclic carboxylic acid anhydride, maleic anhydride,
itaconic anhydride, citraconic anhydride, 3,6-endomethylene-1,2,3,6-tetrahydrophthalic anhydride, methylendomethylenetetrahydrophthalic anhydride,
Examples include tetrahydrophthalic anhydride and 4-methyltetrahydrophthalic anhydride.

The reaction ratio between the aromatic polyamine and the unsaturated cyclic carboxylic acid anhydride may be such that at least two amines remain in one molecule. That is, when an m-valent polyvalent amine is used, it is sufficient to react with (m-2) moles or less of the unsaturated cyclic carboxylic acid anhydride.

In the present invention, when synthesizing an aromatic copolyamide oligomer containing a polymerizable unsaturated group in a side chain, a divalent aromatic diamine can be copolycondensed.

In this case, divalent aromatic diamines that can be used include:
For example, metaphenylenediamine, 44°-diaminodiphenylmethane, 44°-diaminosif-5-nylpropane,
3.3°-dimethyl 4.4′-diaminodiphenylmethane, 4°4-diaminodiphenyl ether, 3.4′ diaminodiphenyl ether, 3.3°-diaminodiphenylsulfone, 4.4°-diaminodiphenyl sulfone, dianisidine, 2.4-Tolylenediamine, 2.4
/2.6-1-lylene diamine mixture, 1.3-bis(3-aminophenoxy)benzene (a, α°-diaminodiphenylxylene), etc. can be used, and two or more types can also be used in combination. It is possible. The amount of divalent aromatic diamine used is preferably 50 mol% or less.

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, and mixtures thereof.

With phthalic acid dichloride, the heat resistance of the aromatic polyamide derived from it is somewhat insufficient, and when using terephthalic acid dichloride, although the heat resistance of the polymer after heat curing is sufficient, the aromatic polyamide obtained as a precursor Polyamide group polyamide oligomers tend to have high melting points and become difficult to handle. From a practical standpoint, isophthalic acid dichloride has the most well-balanced properties and meets the purpose of the present invention.

This synthesis reaction proceeds relatively stoichiometrically, so after calculating by entering the desired value for n in the formula [A1],
It is sufficient to react the required amount of divalent amine having an unsaturated bond and aromatic dicarboxylic acid dihalide, and if precise adjustment is required, the molar ratio can be determined by a simple test.

As already explained, the composition of the unsaturated group-containing aromatic polyamide oligomer obtained by this reaction can be easily selected, and it can be easily molded at a temperature of 200° C. or lower.

The aromatic polyamide oligomer having an unsaturated group at the end 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 usage state of the radical generating catalyst is 1 to 3 phr.

Further, the combined use of a monomer copolymerizable with the unsaturated bond of the oligomer of the present invention is possible when the monomer dissolves the aromatic polyamide oligomer, and is particularly applicable when n in the formula [A1] is a small value. Wide range. Although the combined use of Chitsumar 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, so the amount of addition should be adjusted depending on the purpose. It is necessary to.

When manufacturing a molded article using the aromatic polyamide oligomer having an unsaturated group at the end according to the present invention, reinforcing agents, fillers, mold release agents, coloring agents, other polymers as low shrinkage agents, etc. may be added as necessary. Of course, they can be used together.

[Example] Next, in order to help the understanding of the present invention, examples are shown below.

(Example 1) Synthesis of unsaturated group-containing aromatic polyamide oligomer using Anilix*-maleic anhydride adduct as a divalent amine component 500 equipped with a reflux condenser, dropping funnel, thermometer, and stirrer
10.15 g (0.05 mol) of isophthalic acid dichloride, DMFlo in a four-necked separable flask at m°C.
og and cooled to below 10°C.

Next, an adduct obtained by reacting 28.8 g of Anilix* and 5.88 g of maleic anhydride in 10.5 g of triethylamine and 80 g of DMF is added dropwise to the reaction flask. During this time, the reaction temperature is kept below 10°C. After the dropping is completed, the dropping funnel is washed with 20 g of DMF, and the washing liquid is added to the reaction flask.

Furthermore, stirring is continued for 2 hours while keeping the temperature of the reaction mixture below 10°C.

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.

The m and p of the product are 115 to 140°C, and the infrared absorption spectrum of this product is shown in FIG.

(Examples 2 to 3) Synthesis of an aromatic polyamide oligomer containing an unsaturated group using an anilic-hymic anhydride and an anilic-tetrahydrophthalic anhydride adduct as a divalent amine component Examples except that the formulations shown in the table below were used. The procedure was the same as in 1.

Table (Example 4) Synthesis of unsaturated group-containing aromatic boamide oligomer using anilic-methacrylic acid chloride condensate as divalent amine component 500 equipped with a reflux condenser, dropping funnel, thermometer, and stirrer
10.15 g (0.05 mol) of isophthalic acid dichloride in a four-necked separable flask at m°C, DMF 1
00g and cooled to below 10''C.

Next, 288g of Anilix and methacrylic acid chloride (
Purity 95%<) 4.4g to triethylamine 14.35g
g. The condensate reacted in 80 g of DMF is added dropwise to the reaction flask. During this time, the reaction temperature is kept below 10°C. After the dropping is completed, the dropping funnel is washed with 20 g of DMF, and the washing liquid is added to the reaction flask.

Furthermore, stirring was continued for 28 r while keeping the temperature of the reaction mixture below 10°C.

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.

The m and p of the product are 70 to 105°C, and the infrared absorption spectrum of this product is shown in FIG.

(Example 5) Anilic-methacrylic acid chloride condensate and 3.4
Synthesis of an aromatic copolyamide oligomer containing an unsaturated group using a mixture of diaminodiphenyl ether (abbreviated as 34'-DAPE) as the diamine component 288 g of anilix and 4.4 g of methacrylic acid chloride (purity < 95%) were mixed with 14 g of triethylamine. 35g,
Instead of the condensate reacted in 80 g of DMF, 144 g of Anilix and methacrylic acid chloride (purity 95%) were used.
<) 2.2g, triethylamine 12.23g, DMF
The condensate and 3.4'-DAPE6 reacted in 80g
The same operation as in Example 4 was performed except that a mixture of g was used.

The m and p of the product are 100 to 130°C, and the infrared absorption spectrum of this product is shown in FIG.

[Effect of the invention] Conventional aromatic polyamide is a thermoplastic resin,
Although it had a high melting point and had excellent properties such as chemical resistance and electrical properties, it had problems with moldability and its mechanical strength decreased significantly at high temperatures, so it Even at temperatures below, there were restrictions on the field of use.

The present invention improves these shortcomings and creates a new unsaturated polyamide that can be used as a raw material for thermosetting aromatic polyamides that have excellent moldability and exhibit little decrease in mechanical strength even at high temperatures. We have succeeded in developing aromatic polyamide oligomers containing groups.

This oligomer can be synthesized at low temperatures, and although it has a polymerizable double bond, it is relatively stable and does not gel during the molding process, and because of the action of a radical-generating catalyst, it can be easily synthesized even at low temperatures. It has excellent properties that allow it to be hardened.

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 5 are infrared absorption spectra of the unsaturated group-containing aromatic polyamide oligomers obtained in Examples 1 to 5, respectively. Figure 1 Figure 3 Figure 2 Figure 4

Claims (4)

[Claims] (1) General formula▲There are mathematical formulas, chemical formulas, tables, etc.▼・・・・・・［I］ [However, in the formula, R_1 is a divalent aromatic group, and R_2 is derived from a trivalent or higher polyvalent aromatic polyamine. A is a residue derived from an aliphatic or aromatic polymerizable unsaturated carboxylic acid bonded to an aromatic polyamine via an amide bond, and n is 0 to 15. ] Polymerizable unsaturated group-containing polyamide oligomer. (2) A divalent amine with an unsaturated bond obtained from a condensate of an aromatic polyamine and an unsaturated carboxylic acid chloride, and an unsaturated bond obtained from an adduct of an aromatic polyamine and an unsaturated cyclic carboxylic acid anhydride. 1. A method for producing an aromatic polyamide oligomer containing a polymerizable unsaturated group in a side chain, which comprises reacting a divalent amine or a mixture thereof with an aromatic dicarboxylic acid dihalide in the presence of a hydrogen halide acceptor. (3) Divalent amines with unsaturated bonds are aromatic polyamines represented by the following formula ▲ Numerical formulas, chemical formulas, tables, etc. are available ▼・・・・・・［II］ (α = 1 to 10) ) and an unsaturated carboxylic acid chloride or an addition reaction between an aromatic polyamine represented by the above formula and an unsaturated cyclic carboxylic acid anhydride. A method for producing an aromatic polyamide oligomer containing an unsaturated group according to item 2. (4) Claim 2, in which a divalent aromatic diamine is copolycondensed when a divalent amine having an unsaturated bond and an aromatic dicarboxylic acid dihalide are reacted in the presence of a hydrogen halide acceptor. A method for producing an aromatic polyamide oligomer containing a polymerizable unsaturated group in the side chain as described above.