JPH075835B2 - Thermosetting resin composition - Google Patents

Description

TECHNICAL FIELD The present invention relates to a heat-resistant synthetic resin, and particularly to a heat-resistant thermosetting resin composition having excellent processability.

[Prior Art] As the demand of the plastics industry has become more sophisticated, industrial materials having special materials have been required, and this tendency is rapidly developing in association with the sophistication of the technology.

The demands for improved heat resistance include plastics, films, fibers,
This is 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 a wide range of new fields with new functions.

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

As aromatic polyamides, polyparaphenylene terephthalamide (trade name: Kevlar) 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 generally considered that the melting point was sufficiently higher than that of the conventional thermoplastic synthetic resin, and that it was judged that the introduction of the unsaturated bond had a large risk of causing undesired gelation during the molding process.

On the other hand, apart from this, it is also well known that one of typical heat-resistant resins is polymer formation by addition reaction of amino group to unsaturated bond by Michael reaction of dimaleimides and aromatic diamine ( France Rhône-Poulin company "Kelimide").

However, when it is attempted to homopolymerize maleimides, the polymerization reaction becomes too vigorous at high temperatures, and it has been difficult to obtain useful polymers.

[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 an aromatic polyamide resin having improved molding processability, mechanical strength at high temperature, and improved chemical stability without losing these excellent properties of aromatic polyamide. It was done.

[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 oligomer which can be cured under mild conditions and has sufficient heat resistance, mechanical strength and chemical stability after curing, a cyclic unsaturated imide compound, a cyclic unsaturated acid anhydride or an aromatic Reacting a diamine and an aromatic dicarboxylic acid dihalide in the presence of a hydrogen halide acceptor,
An aromatic polyamide oligomer having a radically polymerizable terminal unsaturated cyclic group was obtained.

It was found that this oligomer can be cured in the presence of a radical-generating catalyst, and that this cured aromatic polyamide has the above-mentioned excellent properties, but it can be cured by using maleimides in addition to this oligomer. By improving the speed and selecting the mixing ratio of both, the melting point of the mixture before curing can be lowered, and a molded product having insufficient heat resistance, mechanical strength and chemical stability after curing can be obtained. Therefore, the present invention has been completed by knowing that such desired improvements can be made.

The aromatic polyamide oligomer having a cyclic aliphatic unsaturated group at the terminal of the carbon chain of the present invention can be represented by the following reaction formula as an example.

In order to allow the reaction of the above [II] to proceed smoothly, a hydrogen chloride acceptor, which is a by-product, is required, and it is generally convenient to use an aliphatic tertiary amine or caustic alkali.

In this case, a value of n of about 1 to 15, preferably about 3 to 7, is advantageous from the viewpoint of easy moldability, and polymerizing at this stage is not particularly necessary. In this reaction, amines are generally mixed in an aqueous phase and acid chloride is mixed with an inert organic solvent which is insoluble in water to carry out an interfacial polycondensation reaction, or both are dissolved in an inert organic solvent and condensed at a low temperature. It can be carried out by a low temperature solution polycondensation reaction.

The precursor of an organic residue having a cyclic unsaturated group at the terminal which can be used in the present invention includes: 1) a cyclic unsaturated imide compound; (However, R ₅ and R ₆ are H or CH ₃ , and at least one is H.) 2) Cyclic unsaturated acid anhydride; maleic anhydride, citraconic anhydride, tetrahydrophthalic anhydride, methyl-tetrahydro Examples thereof include phthalic anhydride, endomethylene-tetophhydrophthalic anhydride, and methylendomethylenetetrahydrophthalic anhydride.

As the aromatic dicarboxylic acid dihalide that can be used in the present invention, a dichloride of an aromatic dibasic acid is convenient, and for example, terephthalic acid dichloride, isophthalic acid dichloride, phthalic acid dichloride or a mixture thereof is typical. The heat resistance of aramid after curing is insufficient for phthalic acid dichloride, and the heat resistance is sufficient when using terephthalic acid dichloride, but the melting point of the aromatic polyamide oligomer obtained is high, making handling difficult. Isophthalic acid dichloride is the most suitable for the purpose of the present invention in terms of practicality.

Examples of aromatic diamines 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, etc. It is possible to use, and it is also possible to use a mixture of two or more kinds.

Since this synthetic reaction proceeds in a relatively stoichiometric manner, a desired value is added to n in the above formula [II] to calculate the required amount of the cyclic unsaturated imide compound or cyclic unsaturated acid anhydride. , The aromatic diamine and the aromatic dicarboxylic acid dihalide may be reacted, and if precise adjustment is required, the molar ratio can be determined by a simple test.

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

The aromatic polyamide oligomer having a cyclic unsaturated group at the terminal, which is 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 maleimides used in combination with the aromatic polyamide oligomer are classified into the following three types.

(I) Phenylmaleimides (ii) Dimaleimides synthesized from aromatic diamine and maleic anhydride The types of aromatic diamines described above are used.

(Iii) Polymaleimide synthesized from aniline-formaldehyde condensate and maleic anhydride Furthermore, (i), (ii) and (iii) can be mixed and used.

Although phenylene imide has a low melting point and has a wide compatibility with aromatic polyamide oligomers, it has a point that it is slightly lacking in heat resistance, and therefore dimaleimides made from aromatic diamine are generally used.

Examples of these are N-phenylmaleimide, N-
(O-chlorophenyl) maleimide, N, N'-diphenylmethane bismaleimide, N, N'-diphenyl ether bismaleimide, N, N'-paraphenylene bismuthleimide, N, N '-(2-methylmetaphenylene) bismaleimide , N, N′-metaphenylene bismaleimide, N, N ′
Examples thereof include-(3,3'-dimethyldiphenylmethane) bismaleimide, N, N '-(3,3'-diphenylsulfone), bismaleimide, and a maleimide compound of an aniline-formaldehyde condensate.

The aromatic polyamide oligomer having a polymerizable cyclic aliphatic unsaturated group at the end of the present invention generally has a slow curing rate, and it is necessary to heat it to a high temperature for a relatively long time even if a radical generator is used as a catalyst. However, the curing rate can be improved by blending the maleimide derivative.

Furthermore, it has the effect of improving the moldability (decreasing the melting point) of the composition containing maleimide before curing, and enables processing at low pressure.

The compounding ratio of the aromatic polyamide oligomer and the maleimide derivative is 10 to 200 parts by weight, preferably 10 to 100 parts by weight, based on 100 parts by weight of the aromatic polyamide oligomer.

When the amount of maleimide added is 10 parts by weight or less, the heat resistance is good, but the drop in melting point is small and the effect of improving moldability is small. Further, even if it is more than 200 parts by weight, the melting point shows a substantially constant value, not only the melting point effect is not observed, but also the heat resistance of the molded body decreases, at the same time the polymerization reaction becomes violent, it becomes difficult to control There is a problem.

The mixture of the aromatic polyamide oligomer and the maleimides according to the present invention can be cured by using a radical generating catalyst in combination, and the heat resistance can be significantly improved.

The radical generating catalyst does not need to be limited, but when the molding temperature is 100 ° C or higher, so-called high temperature decomposition type,
For example, dicumyl peroxide type is used.

It is suitable to use 1 to 3 phr.

Further, the combined use of the unsaturated bond of the oligomer and the copolymerizable monomer is possible when the monomer dissolves the aromatic polyamide oligomer and the maleimide derivative under the curing reaction condition, and particularly n in the formula [I] is When the value is small, the applicable range is wide.

The aromatic polyamide oligomer having a cyclic unsaturated group at the end according to the present invention can, of course, be used in combination with a reinforcing agent, a filler, a release agent, a colorant, a polymer and the like when necessary.

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

[Example] <Synthesis example 1> 500 ml equipped with a reflux condenser, an appropriate lower funnel, a thermometer, and a stirrer
In a four-necked separable flask, 20.3 g (0.1 mol) of isophthalic acid chloride, N- (3-carboxyphenyl)
Maleimide acid chloride (MAB) 9.42 g (0.04 mol),
Charge 100 g of dimethylformamide (DMF) and cool to below 10 ℃.

Next, 3,4'-diaminodiphenyl ether (3,4'-DAP
E) 24.0 g (0.12 mol), triethylamine 22.44 g (0.24
2 mol) and 80 g of DMF are weighed and mixed, and put into a reaction flask.

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

After the addition is complete, keeping the temperature of the reaction mixture below 10 ° C,
Continue stirring for 2 hours.

Then, the reaction mixture is gradually added to a large amount of water with vigorous stirring to precipitate crystals. The precipitated crystals were suction filtered, washed with water and dried to obtain an oligomer [I].

<Synthesis Examples 2 to 4> Operations were performed under the same conditions as in Synthesis Example 1 except that the composition was as shown in Table 1.

<Synthesis Example 5> Synthesis of amino-terminated aromatic polyamide oligomer (4TC-
6); 500 ml equipped with a reflux condenser, an appropriate lower funnel, a thermometer, and a stirrer
Charge 20.3 g (0.1 mol) of isophthalic acid chloride and 100 g of DMF into a 4-neck separable flask and cool to 10 ° C or lower.

Next, 23.33 g (0.117 mol) of 3,4'-DAPE, 20.2 g (0.2 mol) of triethylamine and 80 g of DMF are weighed and mixed, and put into a reaction flask. Meanwhile, the reaction temperature is kept at 1 ° C. or lower.

After the completion of the appropriate time, the appropriate funnel is washed with 20 g of DMF, and the washing solution is added to the reaction flask. After the addition is complete, increase the temperature of the reaction mixture.
Continue stirring for 2 hours while maintaining the temperature below 10 ° C.

Then, 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.

mp165-175 ° C 500 ml equipped with a reflux condenser, an appropriate lower funnel, a thermometer, and a stirrer
4TC-6 43.6 g (0.02 mol), maleic anhydride 3.92 g (0.04 mol), DMF 100 g, and toluene 50 g are charged into a four-necked separable flask of the above, and the mixture is refluxed for 1 hour.

Next, a partial condenser is attached, and the produced water is removed azeotropically with toluene. After removing water and toluene,
The reaction mixture is gradually added to a large amount of water with vigorous stirring to precipitate crystals. The precipitated crystals were suction filtered, washed with water and dried to obtain an oligomer [V].

<Synthesis Examples 6 and 7> Operations were performed under the same conditions as in Synthesis Example 5 except that the composition was as shown in Table 2.

(Example 1) 1 part by weight of the oligomer [I] synthesized in Synthesis Example 1, 0.154 parts by weight of N-phenylmaleimide, and 1.15 parts by weight of a 2% acetone solution of dicumyl peroxide were added to a test tube and mixed uniformly.

Next, the temperature was gradually raised, and the mixture was heated at 80 ° C. for 1 hour to remove acetone and dried. After drying, the temperature was raised to 160 ° C. and curing was carried out for 2 hours. When the temperature was further raised to 200 ° C. and post-curing was carried out for 5 hours, a solid, insoluble and infusible bulk polymer having an amber color was obtained.

The obtained polymer was crushed in a mortar and subjected to thermogravimetric analysis in air at a temperature rising rate of 10 ° C./min.
It became like.

95% weight retention temperature 342 ° C 90% weight retention temperature 395 ° C 500 ° C weight retention 76.7% (Example 2) 1 part by weight of the oligomer [I] synthesized in Synthesis Example 1, 1 part by weight of N-phenylmaleimide, The same operation as in Example 1 was performed except that 2 parts by weight of a 2% acetone solution of dicumyl peroxide was used.

The obtained polymer was crushed in a mortar and subjected to thermogravimetric analysis in air at a temperature rising rate of 10 ° C./min. As a result, it became as shown in (2) of FIG.

95% weight retention temperature 354 ° C 90% weight retention temperature 381 ° C 500 ° C weight retention 73.4% (Example 3) 1 part by weight of the oligomer [I] synthesized in Synthesis Example 1, N, N '
The same operation as in Example 1 was performed, except that 1 part by weight of diphenylmethane bismaleimide and 2 parts by weight of a 2% acetone solution of dicumyl peroxide were used.

The obtained polymer was crushed in a mortar and subjected to thermogravimetric analysis in air at a temperature rising rate of 10 ° C./min, and the result was as shown in (3) of FIG.

95% weight retention rate temperature 429 ° C 90% weight retention rate temperature 464 ° C 500 ° C weight retention rate 82.1% (Example 4) 1 part by weight of the oligomer [II] synthesized in Synthesis Example 2, N, N '
The same operation as in Example 1 was performed, except that 1 part by weight of diphenylmethane bismaleimide and 2 parts by weight of a 2% acetone solution of dicumyl peroxide were used.

The obtained polymer was pulverized in a mortar and subjected to thermogravimetric analysis in air at a temperature rising rate of 10 ° C./min. As a result, it was as shown in (4) of FIG.

95% weight retention temperature 447 ° C 90% weight retention temperature 476 ° C 500 ° C weight retention 85.6% (Example 5) 1 part by weight of the oligomer [III] synthesized in Synthesis Example 3, N, N '
The same operation as in Example 1 was performed, except that 1 part by weight of diphenylmethane bismaleimide and 2 parts by weight of a 2% acetone solution of dicumyl peroxide were used.

The obtained polymer was pulverized in a mortar and subjected to thermogravimetric analysis in air at a temperature rising rate of 10 ° C./min, and the result was as shown in (1) of FIG.

95% weight retention rate 420 ° C. 90% weight retention rate temperature 459 ° C. 500 ° C. weight retention rate 82.2% (Example 6) 1 part by weight of the oligomer [IV] synthesized in Synthesis Example 4, N, N ′
The same operation as in Example 1 was performed, except that 1 part by weight of diphenylmethane bismaleimide and 2 parts by weight of a 2% acetone solution of dicumyl peroxide were used.

The obtained polymer was pulverized in a mortar and subjected to thermogravimetric analysis in air at a temperature rising rate of 10 ° C./min. As a result, it was as shown in (2) of FIG.

95% weight retention rate temperature 402 ° C 90% weight retention rate temperature 429 ° C 500 ° C weight retention rate 75.5% (Example 7) 1 part by weight of the oligomer [V] synthesized in Synthesis Example 5, N, N '
The same operation as in Example 1 was performed, except that 1 part by weight of diphenylmethane bismaleimide and 2 parts by weight of a 2% acetone solution of dicumyl peroxide were used.

The obtained polymer was pulverized in a mortar and subjected to thermogravimetric analysis in air at a temperature rising rate of 10 ° C./min, and the result was as shown in (3) of FIG.

95% weight retention rate temperature 402 ° C 90% weight retention rate temperature 444 ° C 500 ° C weight retention rate 80.0% (Example 8) 1 part by weight of oligomer [VI] synthesized in Synthesis Example 6, N, N '
The same operation as in Example 1 was performed, except that 1 part by weight of diphenylmethane bismaleimide and 2 parts by weight of a 2% acetone solution of dicumyl peroxide were used.

The obtained polymer was crushed in a mortar and subjected to thermogravimetric analysis in air at a temperature rising rate of 10 ° C./min. As a result, the result was (4) in FIG.

95% weight retention temperature 422 ° C 90% weight retention temperature 449 ° C 500 ° C weight retention 79.6% (Example 9) 1 part by weight of the oligomer [VII] synthesized in Synthesis Example 7, N, N '
The same operation as in Example 1 was performed, except that 1 part by weight of diphenylmethane bismaleimide and 2 parts by weight of a 2% acetone solution of dicumyl peroxide were used.

The obtained polymer was crushed in a mortar and subjected to thermogravimetric analysis in air at a temperature rising rate of 10 ° C./min, and the result was as shown in (5) of FIG.

95% weight retention rate temperature 431 ° C 90% weight retention rate temperature 462 ° C 500 ° C weight retention rate 82.6% (Example 10) 100 parts by weight of the oligomer [I] synthesized in Synthesis Example 1, N, N '
A glass cloth was immersed in a solution prepared by dissolving 100 parts by weight of diphenylmethane bismaleimide and 3 parts of dicumyl peroxide in 200 parts of DMF, and then dried at 100 ° C. for 1 hour to prepare a prepreg. After that, several prepregs were superposed and heated and pressed at a pressure of 30 kg / cm ² and a temperature of 160 ° C. for 1 hour, and then 2
Post-curing was carried out at 00 ° C. for 5 hours to obtain a laminated plate.

The bending strength of this laminate is 55 kg / mm ² at 25 ° C,
It was 46 kg / mm ² at 200 ° C. The bending strength after heating at 200 ° C for 200 hours was 56 kg / mm ² at 25 ° C.

Reference Example 1 A composition obtained by adding maleimides to an aromatic polyamide oligomer has a significantly lowered melting point and is easily processed.

As an example, the melting points of N-phenylmaleimide and the oligomer [I] obtained in Synthesis Example 1 at various mixing ratios are shown in Table-3.
Shown in.

[Advantages of the Invention] The present invention is a thermosetting polyamide resin excellent in heat resistance that does not lose the excellent material of aromatic polyamide and does not deteriorate in mechanical properties even at high temperature. It was possible to provide a curable resin composition having improved properties.

[Brief description of drawings]

FIG. 1 shows the results of thermogravimetric analysis of the cured resin compositions of Examples 1 to 4 and FIG.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI Technical display location C07D 209/52 9284-4C C08F 222/40 MNE 299/02 MRU C08G 69/48 NRH C08K 5/3415 KKZ C08L 61/32 LNP

Claims (4)

[Claims] 1. A thermosetting resin composition containing (a) an aromatic polyamide oligomer having a cyclic aliphatic unsaturated group at the terminal and represented by the general formula [I] and (b) maleimide derivative. . 2. The maleimide derivative according to claim 1, wherein the maleimide derivative is at least one of phenylmaleimide, aromatic dimaleimide and aromatic polymaleimide. 3. The aliphatic unsaturated group of the aromatic polyamide oligomer according to claim 1, Is an aromatic polyamide. 4. The maleimide derivative according to claim 1, wherein the maleimide derivative is 10 parts by weight per 100 parts by weight of the polyamide oligomer.
~ 200 parts by weight of a thermosetting resin composition.