JPH0450261A - Thermosetting resin composition - Google Patents

Abstract

PURPOSE:To obtain a thermosetting resin composition having excellent formability and heat-resistance without losing excellent properties of aromatic polyamides by compounding a maleimide derivative to an aromatic polyamide oligomer having cyclic aliphatic unsaturated group on the terminal. CONSTITUTION:The objective thermosetting resin composition can be produced by compounding (A) 100 pts.wt. of an aromatic polyamide oligomer produced by reacting a cyclic unsaturated imide compound or a cyclic unsaturated acid anhydride with an aromatic diamine and an aromatic dicarboxylic acid dihalide in the presence of a hydrogen halide acceptor, having cyclic aliphatic unsaturated group on the terminal and expressed by formula I [R1 and R3 are bivalent aromatic group; R3 is bivalent aliphatic group or aromatic group; A and B are bivalent aliphatic unsaturated group (A may be same to B) of formula II (R<1> and R<2> are H or CH3; at least one of R<1> and R<2> is H); m is 0 or 1; n is 1-15] with (B) 10-200 pts.wt. of a maleimide derivative (e.g. phenylmaleimide, aromatic dimaleimide or aromatic polymaleimide).

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.

[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 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 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 used industrially as plastics with new functions different from conventional synthetic resins. Aromatic boamides, known under the name aramids, are one of them, and are 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 essentially classified as thermoplastic synthetic resins, but they generally have a high melting point, and in some cases the difference between the melting point and the thermal decomposition temperature is small or reversed. 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 heat-cured has not yet been proposed6.
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.

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 in the Michael reaction of simalimides and aromatic diamines ( "Kelimide" by France Rhône-Bouland).

However, when attempting to homopolymerize maleimides, the polymerization reaction is too vigorous at high temperatures, 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 resin that has improved moldability, mechanical strength and chemical stability at high temperatures without losing these excellent properties of aromatic polyamide. This is what I did.

[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 aromatic polyamide oligomers that can be cured under mild conditions and have sufficient heat resistance, mechanical strength, and chemical stability after curing, cyclic unsaturated imide compounds, cyclic unsaturated acid anhydrides, and aromatic Reacting a diamine and an aromatic dicarboxylic acid civalide in the presence of a hydrogen halide acceptor,
An aromatic polyamide oligomer having a radically polymerizable terminal cyclic unsaturated group was obtained.

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. To improve the speed and to lower the melting point of the mixture before curing by selecting the mixing ratio of both, and to obtain a molded product having sufficient heat resistance, mechanical strength and chemical stability after curing. I was able to complete the present invention knowing that such desirable improvements can be made.

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

(Left below) (Cyclic unsaturated imide compound) Metaphenylene diamine (aromatic diamine) Isophthalic acid dichloride (aromatic dicarboxylic acid civalide) 1) Cyclic unsaturated imide compound: (Aromatic polyamide oligomer) [1'I] above In order for the reaction to proceed smoothly, an acceptor for the by-produced hydrogen chloride is required, and it is convenient to use an aliphatic tertiary amine or a caustic alkali.

In this case, n is about 1 to 15, preferably 3 to 7.
This value is advantageous from the viewpoint of ease of moldability, and polymerization at this stage is not particularly necessary.

This reaction is generally carried out 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 in an inert organic solvent and condensing them at low temperatures. It can be carried out by low temperature solution polycondensation reaction.

Precursors of organic residues having a cyclic unsaturated group at the terminal that can be used in the present invention include: 2) Cyclic unsaturated acid anhydrides: maleic anhydride, citraconic anhydride, tetrahydrophthalic anhydride, methyl-tetrahydrophthalic anhydride. , endomethylenetetrahydrophthalic anhydride, methylendomethylenetetrahydrophthalic anhydride, and the like.

Further, as the aromatic dicarboxylic acid civalide 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 the aramid after curing is insufficient, and when using terephthalic acid dichloride, the heat resistance is sufficient, but the resulting aromatic polyamide oligomer has a high melting point (which makes it difficult to handle). From a practical standpoint, isophthalic acid dichloride best meets the purpose of the present invention.

Examples of aromatic diamines include 1, for example 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゛-Diamino diphenyl sulfone, dianisidine, 2
．． 4-)-lylenediamine, 2.472.6-tolylenecyamine mixture, ], 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 by entering the desired value into n in the above formula [11],
All you have to do is react the required amount of cyclic unsaturated imide compound or cyclic unsaturated acid anhydride, aromatic diamine and aromatic dicarboxylic acid civalide, and if precise adjustment is required, the molar ratio can be determined by a simple test. You can decide.

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

The aromatic polyamide oligomer having a cyclic 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.

Maleimides used in combination with aromatic polyamide oligomers can be divided into the following three types.

(il phenylmaleimides (ii) simalimides synthesized from aromatic diamine and maleic anhydride The types of aromatic diamines mentioned above are used.

(iii) Polymaleimide synthesized from aniline-formaldehyde condensate and maleic anhydride Furthermore, it is also possible to use a mixture of (i), fiil, and (iii).

Phenylmaleimide has a low melting point and has wide compatibility with aromatic polyamide oligomers, but it also has a slight lack of heat resistance, so simalemides made from aromatic diamines are used as a material.

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,N'-(3,3°-diphenylsulformaldehyde condensate), and the like.

The aromatic polyamide oligomer of the present invention having a polymerizable cyclic aliphatic unsaturated group at the terminal 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. However, the curing speed can be improved by incorporating a maleimide derivative.

Furthermore, it has the effect of improving the moldability (lowering the melting point) of the composition containing maleimide before curing, and can be processed at low pressure.

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

When the amount of maleimide added is 10 parts by weight or less, the 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.

Aromatic polyamide according to the present invention! A mixture of a nogomer and a maleimide can be cured by the combined use of 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.

The appropriate amount to use is 1 to 3 phr.

In addition, 1,000 polymers can be copolymerized with the unsaturated bonds of oligomers.
The combination of the above is possible when the monomer dissolves the aromatic polyamide oligomer and the maleimide derivative under the curing reaction conditions, and the range of application is particularly wide when n in the formula [I] is a small value.

It goes without saying that the aromatic polyamide oligomer having a cyclic unsaturated group at the terminal according to the present invention can be used in combination with a reinforcing filler, a mold release agent, a coloring agent, a polymer, etc., if necessary, during curing.

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

[Example] <Synthesis Example 1) Synthesis of [oligomer ■] 500 equipped with a reflux condenser, dropping funnel, thermometer, and stirrer
In a mI2 four-neck separable flask, 20.3 g (0.1 mol) of isophthalic acid chloride and N-(3-carboxyphenyl)maleimide acid chloride (MAB) were added.
9.42 g (0.04 mol) and 100 g of dimethylformamide (DMF) were charged and cooled to below 10°C.

Next, 3.4°-diaminodiphenyl ether (3,4'
-DAPE) 24.0 g (0.12 mol), triethylamine 24.44 g (0.242 mol), DMF8
Weigh out 0 g, mix and drop into the reaction flask.

After the addition is complete, the dropping funnel is washed with 20 g of DMF, and the washing liquid is added to the reaction flask.

After the addition is complete, stirring is continued for an additional 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 were suction filtered, washed with water and dried to obtain oligomer [I].

<Synthesis Examples 2 to 4> Operations were carried out under the same conditions as in Synthesis Example 1 except that the formulations shown in Table 1 were used.

(Left below) Table 1 <Synthesis Example 5> Synthesis of amine-terminated aromatic polyamide oligomer (4TC
-6) : MAR: N PAB : N Acid chloride of (3-carboxyphenyl)maleimide (4-carboxyphenyl)maleimide (blank below) Reflux condenser, dropping funnel, thermometer, stirrer 500 with
20.3 g (0.1 mol) of isophthaloyl chloride and DMFloog were placed in a four-neck mβ separable flask and cooled to below 10°C.

Next, 23.33 g (0.117 mol) of 3.4'-DAPE, 20.2 g (0.2 mol) of triethylamine,
Weigh and mix 80 g of DMF and drop it into 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. After the addition is complete, stirring is continued for an additional 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.

m, p, 165-175°C 4TC-643,6g (0,02 mol), maleic anhydride 3.92g (0,04 mol), DMFloog,
50 g of toluene was charged into a reaction flask and refluxed for 1 hour.

Next, turn on the partial condenser and remove the generated water by azeotroping 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 oligomer [V].

<Synthesis Example 6.7> The operation was carried out under the same conditions as Synthesis Example 5 except that the formulation shown in Table 2 was used.

Table-2 500 equipped with reflux condenser, dropping funnel, thermometer, and stirrer
In a mβ four-neck separable flask (Example 1) 1 part by weight of the oligomer [I] synthesized in Synthesis Example 1, N
- 0.154 parts by weight of phenylmaleimide and 1.15 parts by weight of 2% acetone droplets of dicumyl peroxide were added into a test tube and mixed uniformly.

Next, the temperature was gradually raised and heated at 80° C. for 1 hour to remove acetone and dry. After drying, the temperature was raised to 160°C and cured for 2 hours. When the temperature was further raised to 200° C. and curing was carried out after 5 hours, an amber-colored, durable, insoluble and infusible bulk polymer was obtained.

The resulting polymer was crushed in a mortar and thermogravimetrically analyzed in air at a heating rate of 10°C/min.
) became like this.

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 oligomer [I] synthesized in Synthesis Example 1, 1 part by weight of N-phenylmaleimide The same procedure as in Example 1 was carried out, except that 2 parts by weight of a 2% acetone solution of dicumyl peroxide was used.

The resulting polymer was crushed in a mortar and thermogravimetrically analyzed in air at a heating rate of 10°C/min.
2) became like this.

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

The resulting polymer was crushed in a mortar and thermogravimetrically analyzed in air at a heating rate of 10°C/min.
3) became like this.

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

The resulting polymer was crushed in a mortar and thermogravimetrically analyzed in air at a heating rate of 10°C/min.
4) It became like this.

95% weight retention temperature 447°C 90% weight retention temperature 476°C 500°C Weight retention 85.6% (Example 5) Oligomer [m] synthesized in Synthesis Example 3 1 part by weight, N, N
The same procedure as in Example was carried out 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 resulting polymer was crushed in a mortar and thermogravimetrically analyzed in air at a heating rate of 10°C/min.
1) became like this.

95% weight retention temperature 420°C 90% weight retention temperature 459°C 500°C Weight retention 82.2% (Example 6) Oligomer synthesized in Synthesis Example 4 [rV] 1 part by weight, N
, 1 part by weight of N'-diphenylmethane bismaleimide,
The same procedure as in Example I was carried out, except that 2 parts by weight of a 2% solution of dicumyl peroxide in acetone was used.

The resulting polymer was crushed in a mortar and thermogravimetrically analyzed in air at a heating rate of 10°C/min.
2) 695% weight retention temperature 402
°C 90% weight retention temperature 429 °C 500 °C Weight retention rate 75.5% (Example 7) Oligomer [v] synthesized in Synthesis Example 5 1 part by weight, N,
The same operation as in Example 1 was performed except that 1 part by weight of N'-diphenylmethane bismaleimide and 2 parts by weight of a 2% acetone solution of dicumyl peroxide were used.

The resulting polymer was crushed in a mortar and thermogravimetrically analyzed in air at a heating rate of 10°C/min.
3) became like this.

95% weight retention temperature 402°C 90% weight retention temperature 444°C 500°C Weight retention 800% (Example 8) Oligomer [VT] synthesized in Synthesis Example 6 1 part by weight, N
, 1 part by weight of N'-diphenylmethane bismaleimide,
The same procedure as in Example 1 was carried out except that 2 parts by weight of a 2% solution of dicumyl peroxide in acetone was used.

The resulting polymer was crushed in a mortar and thermogravimetrically analyzed in air at a heating rate of 10°C/min.
4) It became like this.

95% weight retention temperature 422°C 90% weight retention temperature 449°C 500°C Weight retention 796% (Example 9) Oligomer synthesized in Synthesis Example 7 [■] 1 part by weight, N,
The same procedure as in Example 1 was carried out except that 1 part by weight of N'-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 thermogravimetrically analyzed in air at a heating rate of 10°C/min.
5) It became like this.

95% weight retention temperature 431°C 90% weight retention temperature 462°C 500°C Weight retention 82.6% (Example 10) 100 parts by weight of oligomer [I] synthesized in Synthesis Example 1, N
, a glass cloth was immersed in a solution of 100 parts by weight of N'-diphenylmethane bismaleimide and 3 parts of dicumyl peroxide dissolved in 200 parts of DMF, and then heated at 100°C for 1 hour.
A prepreg was prepared by drying for a while. After that, several sheets of this prepreg were stacked together under a pressure of 30 kg/cm2.
After heating and pressurizing at a temperature of 160°C for 1 hour, post-curing was performed at 200°C for 5 hours to obtain a laminate.

The bending strength of this laminate is 55Kg/mt at 25℃
*2, and 46 Kg/mwa at 200℃
The bending strength after heating at 200°C for 200 hours was 56 Kg/mm2 at 25°C (Reference Example 1). This makes processing easier.

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

Table 3 [Effects of the Invention] The present invention is a thermosetting polyamide resin with excellent corrosion resistance that does not lose the excellent properties of aromatic polyamide and does not deteriorate in mechanical properties even at high temperatures. In particular, it was possible to provide a curable resin composition with 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, and FIG. 2 shows the results of thermogravimetric analysis of the cured resin compositions of Examples 5 to 9. Patent applicant Showa Kobunshi Co., Ltd.

Claims (4)

[Claims] (1) (a) A thermosetting resin composition containing an aromatic polyamide oligomer having a cyclic aliphatic unsaturated group at the terminal and represented by the general formula [I] and (b) a maleimide derivative. ▲There are mathematical formulas, chemical formulas, tables, etc.▼... [I] [However, in the formula, R_1 and R_2 are divalent aromatic groups, 1R_
3 represents a divalent aliphatic group or an aromatic group, A and B represent a divalent aliphatic unsaturated group (A=B is also acceptable), and m is 0.
Alternatively, 1 and n are any numerical values from 1 to 15. ] (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 represented by ▲a mathematical formula, a chemical formula, a table, etc.▼, ▲a mathematical formula, a chemical formula,
There are tables, etc. ▼ or ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ [However, R^1 and R^2 are H or CH_3, and at least one is H. ] An aromatic polyamide. (4) In claim 1, 10 to 10 parts by weight of the maleimide derivative is added to 100 parts by weight of the polyamide oligomer.
200 parts by weight of a thermosetting resin composition.