JPH03166209A - Thermo-setting resin composition - Google Patents

Abstract

PURPOSE:To obtain the subject composition excellent in heat resistance, curing characteristics and processability by blending a specified aromatic polyamide oligomer with a maleinimide derivative. CONSTITUTION:An objective composition prepared by blending (A) an aromatic polyamide oligomer of the formula (R is H or CH3; R1 and R2 are divalent aromatic group; m is 0-15) having a terminal aliphatic unsaturated group with (B) a maleinimide derivative (preferably phenylmaleinimide, aromatic dimaleinimide or aromatic polymaleinimide).

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a heat-resistant synthetic resin, and particularly to a heat-resistant thermosetting resin composition with excellent processability.

[Conventional technology] As the demands of the plastics industry become more sophisticated, industrial materials with special properties are required, and this trend is rapidly developing as technology 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 by adding new functions. In response to these demands, a group of synthetic resins called engineering plastics, such as aromatic polyamides, ponoimides, polysulfones, and polyphenylene oxides, have already been developed, and are being used as plastics with new functions different from conventional synthetic resins. industrially produced,
Aromatic polyamides, also known as aramids, are opening up new demand areas, and one of them is aromatic polyamides, also known as aramids.

Examples of aromatic polyamides include polybaraphenylene terephthalamide (product name: Kevlar) and polymetaphenylene isophthalamide (product name:
Nomex or HT-1) is a typical type. All of these polyamides are essentially classified as thermoplastic synthetic resins, but they generally have a high melting point, and the difference between the melting point and the thermal decomposition temperature is small or reversed in some cases. Therefore, melt molding is difficult or impossible depending on the structure. On the other hand, a type of polyamide in which an oligomer is made as a precursor and then thermosetted has not yet been proposed. The reason why there was no thermosetting aromatic polyamide is that the melting point is generally much higher than that of conventional thermoplastic synthetic resins, and the introduction of unsaturated bonds may cause undesirable gelation during the molding process. This is thought to be because it was judged that there was a high risk of triggering.・On the other hand, it is also well known that one of the typical heat-resistant resins is a polymer formed by adding amino groups to unsaturated bonds using the Michael reaction between dimaleimides and aromatic diamines. (French Rhône-Bouland “Kelimide”).

However, when attempting to homopolymerize maleimides, the polymerization reaction was too violent at Takataki, making it difficult to obtain useful polymers. [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 an aromatic polyamide-based resin that has improved moldability, mechanical strength and chemical stability at high temperatures without losing these excellent properties of aromatic polyamide. It's ours. [Means for Solving Problem L] The present inventors found that when molding as a molding material or as a laminate, it has a relatively low melting point, can be molded into a desired shape under heat and pressure, and is In order to obtain an aromatic polyamide oligomer that can be cured under moderate conditions and has sufficient heat resistance, mechanical strength, chemical stability, etc. after curing, (meth)acrylamide (in the present invention,
Means acrylamide and/or methacrylamide. ), an aromatic polyamide oligomer having a terminal unsaturated group was obtained by reacting an aromatic diamine and an aromatic dicarboxylic acid dihalide in the presence of a hydrogen halide acceptor. It was discovered 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. It is possible to improve the curing speed and lower the melting point of the mixture before curing by selecting the mixing ratio of both, and to have a molded product that has sufficient heat resistance, mechanical strength, and chemical stability after curing. We were able to complete the present invention knowing that such desirable improvements can be made.The aromatic polyamide oligomer having a terminal unsaturated group of the present invention can be represented by the following reaction formula as an example. (Left below) (Aromatic dicarboxylic acid dihalide) (Aromatic polyamide oligomer) [1] In order for the reaction in [1] above to proceed smoothly, an acceptor for the by-produced hydrogen chloride is required, and a general It is convenient to use an aliphatic tertiary amine or a caustic alkali. In this case, n is about 0 to 15 (however, when n = 0, aromatic diamine is not used), preferably 3 to 7.
This value is advantageous because of ease of moldability, and polymerization at this stage is not particularly necessary. This reaction is generally performed by mixing amines in an aqueous phase and acid chlorides in an inert organic solvent that does not dissolve in water to perform an interfacial polycondensation reaction, or by dissolving both components in an inert organic solvent and condensing them at low temperatures. It can be carried out by low-temperature solution polycondensation reaction. Examples of the organic acid amide having a terminal unsaturated group that can be used in the present invention include acrylamide and methacrylamide. 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, or mixtures thereof. With phthalic acid dichloride, the heat resistance of aramid after curing is insufficient, and when terephthalic acid dichloride is used, the heat resistance is sufficient, but the resulting aromatic polyamide oligomer has a high melting point, making it difficult to handle. From a practical standpoint, isophthalic acid dichloride best meets the purpose of the present invention.

Examples of the aromatic diamine include metaphenylene diamine, 4.4°-diaminodiphenylmethane, and 4.4°-diaminodiphenylmethane.
Diaminodiphenylbroban, 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. A mixture of 2.4/2.6-toluylene diamine, 1,3-bis(3-aminophenoxy)benzene, etc. can be used, and it is also possible to use a mixture of two or more types. This synthesis reaction proceeds relatively stoichiometrically, so after calculating n in the above formula [II], the necessary amounts of terminally unsaturated organic acid halide, aromatic diamine, and aromatic dicarboxylic acid dihalide are added. All you have to do is react, and 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 it can be molded at a temperature of 200° C. or lower. 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. Maleimides used in combination with aromatic polyamide oligomers can be divided into the following three types. (it) Phenylmaleimides (iii) Dimaleimides synthesized from aromatic diamine and maleic anhydride The types of aromatic diamines mentioned above are used. (iii) Aniline-formaldehyde condensate and maleic anhydride It is also possible to use a mixture of polymaleimide synthesized from acids, iil, iii. Generally, dimaleimides made from aromatic diamines are used. Examples of these include N-phenylmaleimide, N-(0-chlorophenyl)maleimide, N.N'-diphenylmethane bismaleimide,
N. N'-diphenyl ether bismaleimide, N.
N'-paraphenylene bismaleimide, N,N'-
(2-methylmetaphenylene) bismaleimide, N. N
'-Metaphenylene bismaleimide, N. N'-
(3.3°-dimethyldiphenylmethane)bismaleimide, N. Examples include N'-(3.3°-diphenylsulfone)bismaleimide or a maleimide of an aniline-formaldehyde condensate. The aromatic polyamide oligomer having an unsaturated group at the terminal of the present invention generally has a slow curing speed and requires heating to a high temperature for a relatively long time even if a radical generator is used as a catalyst. The curing speed can be improved by adding . Furthermore, it has the effect of improving the moldability (lowering the melting point) of a composition containing maleimide before curing, and can be processed at low pressure. The blending ratio of the aromatic polyamide oligomer and maleimide derivative is 10 to 10 parts by weight of the maleimide derivative to 100 parts by weight of the aromatic polyamide oligomer.
200 parts by weight, preferably 10-100 parts by weight.
When the amount of maleimide added is 10 parts by weight or less, heat resistance is good, but the melting point decreases so much that the effect of improving moldability is reduced. In addition, even if the amount exceeds 200 parts by weight, the melting point remains almost constant, and not only is no further melting point drop observed, but the heat resistance of the molded product decreases, and at the same time, the polymerization reaction becomes more intense, making it difficult to control. There is a problem. The mixture of aromatic polyamide oligomer and maleimide 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 when the molding temperature is 100°C or higher, a so-called high-temperature decomposition type catalyst, such as a dicumyl peroxide type, is used, and the appropriate amount is 1 to 3 pbr. Further, the combined use of a monomer copolymerizable with an unsaturated bond is possible when the monomer dissolves the aromatic polyamide oligomer and the maleimide derivative under curing reaction conditions, and in particular, n in the formula [1] above is a small value. In this case, the scope of application is wide. It goes without saying that the aromatic polyamide oligomer having unsaturated end groups according to the present invention can be used in combination with reinforcing agents, fillers, mold release agents, colorants, polymers, etc., as necessary, during curing. Next, examples are shown below to help understand the present invention. [Example] (Synthesis Examples 1 to 5) (Left below) 500 equipped with a reflux condenser, dropping funnel, thermometer, and stirrer
Charge 20.3 g (0.1 monomer) of isophthaloyl chloride and 100 g of dimethinoremamide (DMF) into a four-piece mβ separable flask, and cool to below 10°C. Next, 11 (0.0333 mol) of acrylamide or methacrylamide, 20.2 g (0.2 mol) of aromatic diamine, and 20.2 g (0.2 mol) of triethylamine.
mole). Mix 100 g (or 80 g) of DMF on a scale and drop it into the reaction flask. [When using 80 g of DMF, wash the dropping funnel with 20 g of DMF after the dropwise addition, and drop the washing liquid into the reaction flask. ] During this time, keep the reaction temperature below 10°C. After the dropwise addition was completed, the temperature of the reaction mixture was kept below 10°C, and
Continue stirring for an hour. Next, the reaction mixture is gradually added to a large amount of vigorously stirred water to precipitate crystals. The precipitated crystals are filtered with suction, washed with water, and dried. (Example 1) Oligomer [I1 1 part by weight synthesized in Synthesis Example 1, N-
1 part by weight of phenylmaleimide and 2 parts by weight of a 2% acetone solution of dicumyl baroxide were added into a test tube, mixed uniformly, and placed in an oil bath at 90°C to evaporate the acetone and dry. At that time, the mixture was a yellow homogeneous solution. When this yellow homogeneous solution was heated to 120° C. and heated for 3 hours, an amber-colored, strong, lumpy polymer was obtained.

This polymer was further after-cured at 200°C for 5 hours.

The resulting polymer was crushed in a mortar and subjected to thermogravimetric analysis at a heating rate of 10°C/min in air, resulting in the result shown in Figure 1 (1). 95% weight retention temperature 298°C 90% weight retention temperature 334°C 500°C Weight retention rate 61.0% (Example 2) 1 part by weight of Ligomer synthesized in Synthesis Example 1, N.C.
1 part by weight of N'-diphenylmethane bismaleimide and 2 parts by weight of a 2% acetone solution of dicumyl peroxide were added to a test tube, mixed uniformly, and the same procedure as in Example 1 was performed, except that the mixture was heated at 160°C for 3 hours. I did this. The resulting polymer was crushed in a mortar and subjected to thermogravimetric analysis at a heating rate of 10°C/min in air, resulting in the result shown in Figure 1 (2). 95% weight retention temperature 369°C 90% weight retention temperature 418°C 500°C Weight retention rate 76.0% (Example 3) Oligomer synthesized in Synthesis Example 2 instead of oligomer [I] synthesized in Synthesis Example 1 Example 2 except that [n] was used.
I performed the same operation. The resulting polymer was crushed in a mortar and subjected to thermogravimetric analysis at a heating rate of 10°C/min in air, resulting in the result shown in (3) in Figure 1. 95% weight retention temperature 282°C 90% weight retention temperature 344°C 500°C Weight retention rate 57.5% (Example 4) Synthesis Example 3 in place of the oligomer [H] synthesized in Synthesis Example 1
The same operation as in Example 2 was carried out except that the oligomer [ml] synthesized in Example 2 was used.

The resulting polymer was crushed in a mortar and subjected to thermogravimetric analysis at a heating rate of 10°C/min in air, resulting in the result shown in (4) in Figure 1. 95% weight retention temperature 318°C 90% weight retention temperature 420°C 500°C Weight retention rate 74.3% (Example 5) Oligomer synthesized in Synthesis Example 4 instead of oligomer [I] synthesized in Synthesis Example 1 The same operation as in Example 2 was performed except that [rV] was used. The obtained polymer was crushed in a mortar and subjected to thermogravimetric analysis at a heating rate of 10°C/min in air, and the following values were obtained. 95% weight retention temperature 353°C 90% weight retention temperature 423°C 500°C Weight retention rate 75.1% (Example 6) The oligomer synthesized in Synthesis Example 5 was used instead of the oligomer [I] synthesized in Synthesis Example 1. The same operation as in Example 2 was performed except that ligomer [Vl was used. The obtained polymer was crushed in a mortar and subjected to thermogravimetric analysis at a heating rate of 10°C/min in air, and the following values were obtained. 95% weight retention temperature 325°C 90% weight retention temperature 420°C 500°C Weight retention rate 73.2% (Example 7) 40 parts of Ligomer [I] synthesized in Synthesis Example 1, N. N'
- A glass cloth was immersed in a solution of 40 parts of diphenylmethane bismaleimide and 1.6 parts of dicumyl peroxide dissolved in 120 parts of DMF, and then dried at 80° C. for 1 hour to prepare Bripreg. After that, several sheets of this prepreg were stacked together at a pressure of 15 Kg/cm" and a temperature of 160.
After heating and pressurizing at ℃ for 1 hour, curing was performed at 200℃ for 5 hours to obtain a laminate. The bending strength of this laminate is 54κg/ra at 25°C.
m” and 45 Kg/11 at 200°C.Furthermore, the bending strength after heating at 230°C for 200 hours was 52 Kg/11 at 25°C. (Reference Example 1) Fragrance Compositions in which maleimides are added to group polyamide oligomers have a significantly lower melting point and are easier to process.As an example of this, compositions containing N-phenylmaleimide and the oligomer [I] obtained in Synthesis Example 1 were prepared at various mixing ratios. The melting points are shown in Table 1. Table 1 L Effect The present invention is a thermosetting polyamide resin with excellent heat resistance that does not lose the excellent properties of aromatic polyamide and whose mechanical properties do not deteriorate even at high temperatures. Therefore, we were able to provide a curable resin composition with particularly improved curability and processability.

[Brief explanation of the drawing]

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

Claims (3)

[Claims] (1) (a) has an aliphatic unsaturated group at the terminal, and has the general formula [
A thermosetting resin composition comprising an aromatic polyamide oligomer represented by I and a (b)maleimide derivative. ▲There are mathematical formulas, chemical formulas, tables, etc.▼ ... [I] [However, in the formula, R is H or CH_3, R_1 and R_2
is a group selected from divalent aromatic groups, and n is 0 to 15
represents the number of ] (2) The maleimide derivative according to claim 1, wherein the maleimide derivative is at least one of phenylmaleimide, aromatic dimaleimide, and aromatic polymaleimide. (3) In claim 1, polyamide oligomer 1
A thermosetting resin composition in which the maleimide derivative is contained in an amount of 10 to 200 parts by weight based on 00 parts by weight.