JP2545621B2 - Thermosetting resin composition - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial application] The present invention relates to a thermosetting resin composition having excellent mechanical strength and good storage stability without impairing heat resistance.

[Conventional technology]

2. Description of the Related Art Conventionally, thermosetting resins having an imide structure have been widely used industrially because they have excellent electrical insulation properties, heat resistance, and dimensional stability of molded products.

However, the thermosetting resin obtained by thermally polymerizing the aromatic bismaleimide alone is a material having excellent heat resistance, but it has the drawback of being extremely brittle and poor in flexibility.
As a method of improving such a defect, there is an attempt to use a thermosetting resin composition composed of an aromatic bismaleimide and an aromatic diamine, for example, N, N'-4,4'-diphenylmethane bismaleimide and 4 A polyamino bismaleimide resin consisting of 4,4'-diaminophenylmethane (Rourne-Poulin Co., Ltd., trade name Kelimide) has been put into practical use and is widely used for impregnating varnishes, laminated plates, molded articles and the like (Japanese Patent Publication No. 46- 23250).

However, these thermosetting resin compositions have not been satisfactory in impact resistance and flexibility.
Further, when these thermosetting resin compositions are used for laminates, there are drawbacks such as poor solubility in low boiling point solvents and poor storage stability of resin solutions before making prepregs such as glass cloth. is there.

[Problems to be solved by the invention]

An object of the present invention is to provide a thermosetting resin composition having excellent mechanical strength and good storage stability in a solution state.

[Means for solving problems]

As a result of intensive studies to achieve the above-mentioned object, the present inventors have found that a thermosetting resin composition comprising a novel polymaleimide compound and a specific aromatic amine resin is particularly effective, and Completed the invention.

That is, the thermosetting resin composition of the present invention has the general formula (I) (In the formula, n represents an integer of 0 to 50) and 100 parts by weight of the polymaleimide compound represented by the general formula (II). (In the formula, n represents an integer of 0 to 50.) A thermosetting resin composition comprising 5 to 100 parts by weight of an aromatic amine resin represented by the formula.

The polymaleimide compound represented by the general formula (I) can be easily produced by a condensation / dehydration reaction of the aromatic amine resin represented by the general formula (II) and maleic anhydride by a generally known method.

The aromatic amine resin represented by the general formula (II) was previously filed by the present applicant (Japanese Patent Laid-Open Nos. 01-95125 and 01-12382).
8) which has been prepared, for example, aniline and the general formula (II
I) (In the formula, X represents a halogen, a hydroxyl group or an alkoxy group.).

A thermosetting resin composition is obtained from the polymaleimide compound represented by the general formula (I) and the aromatic amine resin represented by the general formula (II). In this case, various methods described below can be used.

Solid polymaleimide compound and aromatic amine resin
A solid, pulverized and mixed, a solid-liquid mixed, or a heat-treated prepolymer is crushed into pellets or powder. In this case, the heating condition is preferably such that the prepolymer stage is partially cured. Generally, the temperature is 70 to 220 ° C. for 5 to 240 minutes, and the temperature is preferably 80 to 200 ° C. for 10 to 180 minutes. Is.

Dissolve the polymaleimide compound and aromatic amine resin in an organic solvent, then discharge into a poor solvent, filter and dry the precipitated crystals into pellets or powder, or dissolve in an organic solvent and heat. After being partially cured to the prepolymer stage by treatment, it is discharged into a poor solvent, and the precipitated crystals are filtered and dried to obtain pellets or powder. The conditions in this case also apply.

The usable organic solvent is limited in that it does not substantially react with both components, but in addition to this, it is desirable that it is a good solvent for both components. Usually, solvents used are halogenated hydrocarbons such as methylene chloride, dichloroethane and trichloroethylene, ketones such as acetone, methyl ethyl ketone, cyclohexanone and diisopropyl ketone, ethers such as tetrahydrofuran, dioxane and methyl cellosolve, benzene, toluene and chlorobenze. Aprotic polar solvents such as aromatic compounds, acetonitrile, N, N-dimethylformamide, N, N-dimethylacetamide, dimethyl sulfoxide, N-methyl-2-pyrrolidone, 1,3-dimethyl-2-imidazolidinone Is.

The compounding amount of the aromatic amine resin represented by the general formula (II) is the polymaleimide compound represented by the general formula (I).
It is used in a proportion of 5 to 100 parts by weight, preferably 10 to 80 parts by weight, based on 0 parts by weight.

When the amount of the aromatic amine resin is 5 parts by weight or less, the cured product is extremely brittle and satisfactory bending strength cannot be obtained, and when it is 100 parts by weight or more, the heat resistance of the cured product is deteriorated.

If necessary, the following components can be added to the thermosetting resin composition of the present invention as long as the object of the present invention is not impaired.

(A) Curing accelerators, for example, azo compounds, radical polymerization initiators such as organic peroxides, tertiary amines, quaternary ammonium salts, imidazoles, ion catalysts such as boron trifluoride / amine salts, etc. .

(B) Reinforcing agents and fillers in powder form, for example, metal oxides such as aluminum oxide and magnesium oxide, metal oxides such as aluminum hydroxide, metal carbonates such as calcium carbonate and magnesium carbonate, diatomaceous earth powder, bases. Examples include system magnesium silicate, calcined clay, fine powder silica, fused silica, crystalline silica, carbon black, kaolin, fine powder mica, quartz powder, graphite, asbestos, molybdenum disulfide, and antimony trioxide.

Further, there are fibrous reinforcing agents and fillers such as glass fibers, rock wool, ceramic fibers, alumina fibers, inorganic fibers such as potassium titanate fibers, carbon fibers, and organic fibers such as aromatic polyamides.

(C) Various synthetic resins can be blended for the purpose of improving the properties of the resin in the final coating film, adhesive layer, resin molded product and the like. For example, thermosetting resins such as phenol resin, epoxy resin, melamine resin, silicone resin, polyamide, polycarbonate, polysulfone, polyethersulfone, polyetheretherketone, modified polyphenylene oxide, polyphenylene sulfide, polyetherimide, fluororesin And so on.

The thermosetting resin composition of the present invention is molded by a known molding method such as a compression molding method, a transfer molding method, an extrusion molding method, and an injection molding method, and put into practical use.

〔Example〕

Hereinafter, the present invention will be described in detail with reference to Synthesis Examples, Examples, and Comparative Examples.

In these examples, the physical properties of the thermosetting resin composition and the like were measured by the following methods.

・ GPC analysis: LC-6A manufactured by Shimadzu Corporation is used.

-Softening point: According to JIS K-2548 (ring and ball softening point measuring method).

-Heat distortion temperature: According to ASTM-D-648.

-Bending strength and flexural modulus: According to ASTM-D-790.

・ Pyrolysis initiation temperature: In the air by the TGA method, heating loss is 10 ℃ / m
Measure the onset temperature of weight loss at in.

-Storage stability of resin solution: N times the resin composition before heat curing.
Dissolve the resin in methyl-2pyrrolidone to a concentration of 50% by weight, and store this resin solution at room temperature.

The state of the resin solution after 30 days has been visually observed.

Synthesis Example 1 1490 g (16 mol) of aniline in a reactor equipped with a water separator,
280.2 g (1.6 mol) of α, α'-dichloro-p-xylene and 175.2 g (4.8 mol) of a 35% hydrochloric acid aqueous solution were charged, and the temperature was raised with stirring while passing nitrogen gas. On the way, distilled water was removed by a water separator, and the temperature was raised to the reflux point of aniline. In this state, the reaction was completed by aging for 15 hours. Next, this reaction liquid was cooled to 140 ° C. and poured into 1600 g of an 18% aqueous sodium hydroxide solution. 1000 g of toluene was added with stirring to complete the neutralization. When it was allowed to stand, it was separated into two layers, so the lower layer was removed by liquid separation, and further water washing and liquid separation were repeated. The obtained oil layer was vacuum condensed to collect toluene and unreacted aniline, and a pale yellow transparent oily aromatic amine resin (II-a) was obtained as a residue.

-Yield: 442 g-Composition by GPC analysis: n value of general formula (I) n = 0.: 76%, n = 1: 19%, n = 2: 4%, n ≧ 3: 1% -Average molecular weight: 350. Amine value: 0.65 eq / 100g Next, a polymaleimide compound (Ia) was produced using this aromatic amine resin (II-a). In a reactor equipped with a water separator, p-toluenesulfonic acid 10 g and toluene 4
00 g was charged, and water was removed by azeotropic dehydration while heating under reflux.

Next, 190 g (1.94 mol) of maleic anhydride was charged therein, and while maintaining the reflux condition, a solution prepared by previously dissolving 200 g of the aromatic amine resin (II-a) in 200 g of toluene was taken for 12 hours. Was dropped. On the way, water distilled azeotropically was removed from the system, and toluene was refluxed. After the dropping is completed,
The reaction was terminated by performing heat aging for 3 hours. The total amount of distillate water was 25 g. The reaction solution was cooled to 70 ° C., and a small amount of insoluble matter was removed by filtration. Then, add 300 g of water and reflux under 30
I kept it for a minute. Since it was separated into two layers by allowing to stand, the lower layer was removed, 500 g of water was further added, and washing and liquid separation were repeated twice. The oil layer was vacuum concentrated to 150 ° C. to obtain a maleimide compound as this residue.

This was discharged at the time of heating, cooled and pulverized to obtain a yellow powdery polymaleimide compound (Ia).

-Yield: 310 g, -Softening point: 94 ° C. Synthesis Example 2 A reactor equipped with a water separator was charged with 558 g (6 mol) of aniline, and the temperature was raised while passing nitrogen gas. When the internal temperature reached 150 ° C, α, α'-dichloro-p-xylene 350.
2 g (2 mol) was dividedly charged so that the internal temperature would not rise sharply.
After charging, the internal temperature was kept at 210 ° C. and aging was carried out for 10 hours to complete the reaction. After the reaction, the post-treatment was carried out in the same manner as in Synthesis Example 1 to carry out neutralization, water separation and concentration to obtain a pale yellow transparent aromatic amine resin (II-b).

-Yield: 460 g-Composition by GPC analysis: n value of general formula (I) n = 0: 36%, n = 1: 22%, n = 2: 14%, n = 3: 9%, n = 4: 6%, n ≧ 5: 13% ・ Average molecular weight: 650, ・ Softening point: 56 ° C ・ Amine value: 0.61eq / 100g Next, using this aromatic amine resin (II-b), a polymaleimide compound ( Ib) was produced. A reactor equipped with a water separator was charged with 40 g of a perfluoroalkanesulfonic acid type ion exchange resin (trade name Nafion-H: manufactured by DuPont) as a catalyst and 400 g of toluene, and further 148.8 g of maleic anhydride (1.6 mol) was added and kept at reflux. Next, 200 g of the aromatic amine resin (II-b) was previously prepared.
A solution of 100 g of N, N-dimethylformamide was added to 10
It broke up over time. After the dissolution, the reaction was completed by aging for 5 hours under reflux. The total amount of distillate water was 24 g.
The reaction solution was cooled to 70 ° C. and filtered to remove Nafion-H.

Next, this filtrate was concentrated under vacuum to remove the solvent toluene and N, N.
-Dimethylformamide was recovered and the product was discharged while hot. After cooling, it was pulverized to obtain a powder of crude polymaleimide compound. This powder was sludged in water 1 at 40 ° C. for a whole day and night, and filtered and washed with water to obtain a yellow powdery polymaleimide compound (Ib).

・ Yield: 290 g, ・ Softening point: 110 ° C. Examples 1 to 7 and Comparative Examples 1 and 2 The polymaleimide compound obtained in Synthesis Example 1 was placed in a stainless steel reaction vessel equipped with a stirrer, a reflux condenser and a nitrogen inlet tube. (I-a) and the aromatic amine resin (II-a),
It is charged in the parts by weight shown in Table 1, heated and melted at 180 ° C for 20 minutes, and further degassed at 150 ° C under reduced pressure (10 to 15 mmHg) for 30 minutes, then cooled to room temperature and brown. A transparent glass-like solidified resin composition was obtained.

The composition was filled in a mold heated to 180 ° C while being heated and melted, and then held at 50 kg / cm ² and 200 ° C for 30 minutes, compression-molded to take out the molded product, and further, in an oven at 250 ° C. Post-cure for 4 hours, then test piece of cured product (vertical 127m
m, width 12.7 mm, thickness 6.4 mm) was obtained.

The heat deformation temperature, bending strength, bending elastic modulus and thermal decomposition initiation temperature of this test piece were measured, and the state of the resin solution was visually observed. The results are shown in Table 1.

Comparative Example 3 N, N'-4,4'-diphenylmethane bismaleimide and 4,
4'-diaminodiphenylmethane was used in the composition shown in Table 1 (weight ratio 100/30), and the same operation as in Examples 1 to 7 was performed to obtain the results shown in Table 1.

Comparative Example 4 Kelimide-1050 (manufactured by Nippon Polyimide Co., Ltd.) was used as the resin composition, and the same operations as in Examples 1 to 7 were performed, and the results shown in Table 1 were obtained.

〔The invention's effect〕

The thermosetting resin of the present invention has excellent heat resistance, impact resistance, and flexibility, and is expected to find wide application in electrical and electronic parts, various structural members, sliding parts, and industrial applications. The effect is great.

Claims (1)

(57) [Claims] 1. A general formula (I) (In the formula, n represents an integer of 0 to 50) and 100 parts by weight of the polymaleimide compound represented by the general formula (II). (In the formula, n represents an integer of 0 to 50.) A thermosetting resin composition comprising 5 to 100 parts by weight of an aromatic amine resin represented by the formula: