JPH075736B2 - Thermosetting resin composition - Google Patents

Description

TECHNICAL FIELD The present invention relates to a novel thermosetting resin composition having excellent mechanical strength without impairing heat resistance.

[Conventional technology]

BACKGROUND ART Conventionally, a thermosetting resin having an imide structure has been widely used in industry because it has excellent electrical insulation properties, heat resistance, and dimensional stability of molded products.

However, the thermosetting resin obtained by thermally polymerizing the aromatic bismaleimide alone has a drawback that it is a material having excellent heat resistance, but is 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 composed of 4,4'-diaminodiphenylmethane (manufactured by Rhone-Poulin, trade name Kelimide) has been put into practical use and is widely used in impregnating varnishes, laminated plates, molded articles and the like (Japanese Patent Publication No. 46-23250). ).

However, these thermosetting resin compositions do not have sufficient heat resistance and are not satisfactory in impact resistance and flexibility.

[Problems that the invention is trying to solve]

An object of the present invention is to provide a thermosetting resin composition having excellent mechanical strength and heat resistance.

[Means for solving problems]

As a result of intensive studies to achieve the above-mentioned objects, the present inventors have found that a thermosetting resin composition comprising N, N′-4,4′-diphenylmethane bismaleimide and a specific aromatic amine resin is particularly effective. That is, the present invention has been completed.

That is, the thermosetting resin composition of the present invention has the formula (I) 100 parts by weight of N, N'-4,4'-diphenylmethane bismaleimide represented by and the aromatic compound represented by the formula (II) (II) (In the formula, A represents a phenylene group, an alkyl-substituted phenylene group, a diphenylene group, a diphenyl ether group or a naphthylenyl group, and R ¹ is a halogen atom, 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 R ¹ may be the same or different from each other and may form a ring, L represents 1 or 2, m represents an integer of 0 to 3, and n represents 0 to 300. It is an integer.) A thermosetting resin composition comprising 5 to 100 parts by weight of an amine resin.

The N, N'-4,4'-diphenylmethane bismaleimide represented by the above formula (I) is easily produced by condensation / dehydration reaction of 4,4'-diaminodiphenylmethane and maleic anhydride by a known method. it can.

The specific aromatic amine resin (II) used in the present invention has the general formula (IV) R ² OCH ₂ —A—CH ₂ OR ² (IV) (wherein A is a phenylene group, an alkyl-substituted phenylene group, diphenylene). Group, a diphenyl ether group or a naphthylenyl group, and R ² represents a hydrogen atom, an acyl group or a lower alkyl group having 4 or less carbon atoms.) To 1 mol of the aralkyl alcohol derivative represented by the general formula (III). (In the formula, R ¹ represents a halogen atom, 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 R ¹ may be the same or different from each other,
You may form a ring. L represents 1 or 2, m is 0
Indicates an integer of 3. ) The aromatic amine compound represented by 1
It is obtained by reacting at a ratio of ~ 15 mol (Japanese Patent Application No. 62-25251).
7 (Publication of Japanese Patent Application Laid-Open No. 1-95125) This is a new resin.

A of the aralkyl alcohol derivative represented by the general formula (IV) of the raw material is And R ² is a hydrogen atom, an acyl group or an alkyl group. Specifically, α, α′-dihydroxy-o-xylene, α, α′-dihydroxy-m-xylene, α,
α'-dihydroxy-p-xylene, α, α'-diacetoxy-o-xylene, α, α'-diacetoxy-m-
Xylene, α, α′-diacetoxy-p-xylene,
α, α′-dipropionoxy-p-xylene, α, α ′
-Di-n-butyroxy-p-xylene, α, α'-dimethoxy-o-xylene, α, α'-dimethoxy-m-xylene, α, α'-dimethoxy-p-xylene, α,
α'-diethoxy-o-xylene, α, α'-diethoxy-m-xylene, α, α'-diethoxy-p-xylene, α, α'-diisopropoxy-o-xylene, α,
α'-diisopropoxy-m-xylene, α, α'-diisopropoxy-p-xylene, α, α'-di-n-propoxy-p-xylene, α, α'-di-n-butoxy- m-xylene, α, α′-di-n-butoxy-p-xylene, α, α′-di-sec-butoxy-p-xylene, α, α′-diisobutoxy-p-xylene, 4,4 ′
-Dihydroxymethyldiphenyl ether, 4,4'-dihydroxymethyldiphenyl, 2,6-dihydroxynaphthalene, 4,4'-diacetoxymethyldiphenyl ether, 4,4'-diacetoxymethyldiphenyl, 2,6-diacetoxymethylnaphthalene, 4,4'-methoxymethyl diphenyl ether, 4,4'-methoxymethyl diphenyl, 4,4'-diethoxymethyl diphenyl ether, 4,
4'-diisopropoxymethyldiphenyl, 4,4'-diisobutoxymethyldiphenyl ether, α, α'-dimethoxy-2-methyl-p-xylene, α, α'-dimethoxy-3-methyl-m-xylene, α , Α'-Dihydroxy-2,5-dimethyl-p-xylene, α, α'-dimethoxy-2,5-dimethyl-p-xylene, α, α'-dimethoxy-2,4-dimethyl-1,3- Xylene, α, α'-
Examples thereof include dimethoxy-2,4-dimethyl-1,5-xylene. In addition, the more preferable compound among them is
It is α, α'-dimethoxy-p-xylene.

In addition, R of the aromatic amine compound represented by the general formula (III) is
¹ is a halogen atom, a hydroxyl group, a lower alkoxy group having 4 or less carbon atoms, or a lower alkyl group having 5 or less carbon atoms,
These are 0 to 3 and may be the same as or different from each other, and may form a ring. The number of amino groups is 1 or 2. Specifically, aniline, o-toluidine, m-toluidine, p-toluidine, o-ethylaniline, m-
Ethylaniline, p-ethylaniline, o-isopropylaniline, m-isopropylaniline, p-isopropylaniline, on-propylaniline, o-tert-
Butylaniline, p-tert-butylaniline, on-
Butylaniline, p-sec-butylaniline, 2,3-xylidine, 2,4-xylidine, 2,6-xylidine, 3,4-xylidine, 3,5-xylidine, 2-methyl-3-ethylaniline, 2 -Methyl-4-isopropylaniline, 2,
6-diethylaniline, 2-ethyl-5-tert-butylaniline, 2,4-diisopropylaniline, 2,4,6-trimethylaniline, 4-chloroaniline, 4-bromoaniline, 4-fluoroaniline, 3-chloro Aniline, 3
-Bromoaniline, 3,4-dichloroaniline, 3-chloro-o-toluidine, 3-chloro-p-toluidine, 2,
6-dimethyl-4-chloroaniline, o-aminophenol, m-aminophenol, p-aminophenol,
2-amino-4-cresol, 4-amino-2-tert-
Butylphenol, 2,6-dimethyl-4-aminophenol, 2,6-dichloro-4-aminophenol, 2-amino-1,3-resorcinol, 4-amino-1,3-resorcinol,
2-aminohydroquinone, 2-methoxyaniline, 3
-Methoxyaniline, 4-methoxyaniline, 2-isopropoxyaniline, 2,4-dimethoxyaniline, o-
Phenylenediamine, m-phenylenediamine, p-phenylenediamine, 2,4-diaminotoluene, 2,6-diaminotoluene, 2,4-diaminoethylbenzene, 2,6-diaminoethylbenzene, 2,4-diaminoisopropylbenzene, 2 , 4-Diamino-tert-butylbenzene, 2,6-
Diamino-tert-butylbenzene, 2,4-diamino-1,3
-Dimethylbenzene, 1,1-dimethyl-4-aminoindan, 1,1-dimethyl-4,6-diaminoindan and the like can be mentioned. Preferred compounds are aniline, toluidines, xylidines, aminophenols and diamines, and particularly preferred is aniline.

The reaction between the aralkyl alcohol derivative (IV) and the aromatic amine compound (III) is carried out in the presence of an acid catalyst such as hydrochloric acid, relative to 1 mol of the aralkyl alcohol derivative, 1 to 15 mol, preferably 1.1 to 10 mol, of the aromatic amine compound. 170 to 24
The condensation reaction is performed at a temperature of 0 ° C for 10 to 40 hours. After the reaction,
The aromatic amine resin of the above formula (II) can be obtained by neutralizing the reaction mixture with an alkali typified by caustic soda, washing with water, and then removing the excess aromatic amine compound under reduced pressure.

The molecular weight range of the obtained aromatic amine resin is 300 to 60,000.
The softening point range of the resin is liquid at room temperature to about 250 ° C (ring and ball softening point according to JIS-K-2548).

A thermosetting resin composition is obtained from N, N'-4,4'-diphenylmethane bismaleimide represented by the above formula (I) and an aromatic amine resin represented by the formula (II). Various methods shown in can be used.

(1) Solid-solid pulverized and mixed bismaleimide and aromatic amine resin, or solid-liquid pulverized mixture, or a heat-treated prepolymer thereof which is then pulverized into pellets or powder. To do. The heating conditions in this case are good conditions to partially cure up to the prepolymer stage, generally 70 to 220 ° C. for 5 to 240 minutes, preferably 80 to 200.
It is suitable that the temperature is 10 to 180 minutes.

(2) Bismaleimide and aromatic amine resin are dissolved in an organic solvent, then discharged into a poor solvent and the precipitated crystals are filtered and dried to form pellets or powder, or dissolved in an organic solvent and then heat-treated. After partially curing to the prepolymer stage by means of, the crystals precipitated after being discharged into a poor solvent are filtered and dried to obtain pellets or powder. The condition in this case also conforms to (1).

The usable organic solvent is limited in that it does not substantially react with both components, but it is desirable that it is a good solvent for both reaction components. Usually, reaction 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 chlorobenzene. Aromatic compounds, acetonitrile, N, N-dimethylformamide, N, N-dimethylacetamide, dimethylsulfoxide, N-methyl-2-
Examples include aprotic polar solvents such as pyrrolidone and 1,3-dimethyl-2-imidazolidinone.

The amount of the aromatic amine resin represented by the formula (II) is 5 to 100 parts by weight with respect to 100 parts by weight of N, N′-4,4′-diphenylmethane bismaleimide represented by the formula (I). It is preferably used in a proportion of 10 to 80 parts by weight.

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

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 ammonia salts, imidazoles, ionic 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 hydroxides such as aluminum hydroxide, metal carbonates such as calcium carbonate and magnesium carbonate, diatomaceous earth powder, bases. Magnesium silicate, calcined clay, finely powdered silica, fused silica, crystalline silica, carbon black, kaolin, finely powdered mica, quartz powder, metal hydroxides such as aluminum hydroxide, graphite, asbestos, molybdenum disulfide, trioxide Such as antimony. Further, there are fibrous reinforcing materials and fillers, for example, inorganic fibers such as glass fibers, rock wool, ceramic fibers, alumina fibers, potassium titanate fibers, carbon fibers, and organic fibers such as aromatic polyamides.

(C) Further, 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 resin such as phenol resin, epoxy resin, melamine resin, silicone resin, polyamide, polycarbonate, polysulfone, polyethersulfone, polyetheretherketone, modified polyphenylene oxide, polyphenylene sulfide, polyetherimide, fluororesin, etc. Is.

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 with reference to examples.

Synthesis Example 1 In a reaction vessel equipped with a stirrer, a thermometer, and a Dean Stark azeotropic distillation trap, 1116 g (12.0 mol) of aniline as an aromatic amine compound represented by the general formula (III) and a general formula (IV) were used. Α, α'-dimethoxy-p-xylene as an aralkyl alcohol derivative
(4.0 mol) and 626 g of 35% hydrochloric acid aqueous solution as a catalyst
(6.0 mol) was charged, and the temperature was raised while nitrogen gas was passed through. Water distilled from the trap at an internal temperature of about 110 ° C was removed to the outside of the system. When the temperature was further raised, distillation of methanol was observed at about 130 ° C. The temperature was continuously raised while distilling off the produced methanol, and after reaching 170 ° C., the temperature was kept constant for 3 hours. Generation of methanol was almost eliminated, and then the temperature was continuously raised and the reaction was carried out at 190 to 200 ° C for 12 hours.

Then, the mixture was cooled and the internal temperature was lowered to 95 ° C., and to this was added 1680 g of a 15% aqueous sodium hydroxide solution, and the mixture was neutralized with stirring. After standing still,
The lower aqueous layer was separated, and 3000 g of saturated saline was added to carry out washing separation. Next, after heating and dehydration under a nitrogen stream, pressure filtration was performed to remove inorganic salts and the like. 2-3 mmH
After vacuum concentration under vacuum of g, 519 g of unreacted aniline was recovered. The remaining amount was discharged to obtain 945 g of light yellowish brown aniline resin.

The aromatic amine resin obtained as described above was subjected to composition analysis by high performance liquid chromatography, and as a result, a compound represented by the general formula (I
In I), n = 0 is 28, n = 1 is 16.8, n = 2 is 10.5, n =
3 was 7.8, and n ≧ 4 was 36.9 (mol%).

The amine equivalent (perchloric acid-glacial acetic acid method) of this resin is
It was 0.578 equivalent / (100 g), the softening point measured by the ring and ball softening point measuring device according to JIS-K-2548 was 68 ° C, and the average molecular weight was 960.

Synthesis Example 2 745 g (8.0 mol) of aniline and α, α′-dimethoxy-p
-Using 664 g (4.0 mol) of xylene and 420 g (4.0 mol) of a 35% hydrochloric acid aqueous solution as a catalyst, the reaction was carried out in the same manner as in Synthesis Example 1 to obtain 747 g of a light yellowish brown aniline resin.

The aromatic amine resin obtained as described above was subjected to composition analysis by high performance liquid chromatography, and as a result, a compound represented by the general formula (I
I) n = 0 is 17.0, n = 1 is 14.5, n = 2 is 13.2, n
≧ 3 was 55.2 (mol%).

The amine equivalent of this resin was 0.520 equivalent / (100 g), the softening point was 61 ° C., and the average molecular edge was 2100.

Synthesis Example 3 2,4 as an aromatic amine compound represented by the general formula (III)
Example 1 except that 244.4 g (2.0 mol) of diaminotoluene was used and 209 g (2.0 mol) of 35% hydrochloric acid was used as the catalyst.
The reaction was carried out in the same manner as described above to obtain 132 g of reddish brown oily diaminotoluene resin.

The aromatic amine resin obtained as described above was subjected to composition analysis by high performance liquid chromatography, and as a result, a compound represented by the general formula (I
I) n = 0 is 44.5, n = 1 is 29.7, n = 2 is 14.6, n
≧ 3 was 11.2 (mol%).

The resin has an amine equivalent of 1.204 and a softening point of 4
The average molecular weight was 550 at 6 ° C.

Synthesis Example 4 121.1 g (1.3 mol) of aniline was used as the aromatic amine compound represented by the general formula (III), and α, α′-dihydroxy-m-xylene was used as the aralkyl alcohol derivative represented by the general formula (IV). The reaction was performed in the same manner as in Synthesis Example 1 except that 138.2 g (1.0 mol) was used and concentrated sulfuric acid 33 g (0.325 mol) was used as a catalyst.
Got

The equivalent weight of the aromatic amine resin thus obtained was 0.496.
The softening point measured by the ring and ball softening point measuring device according to JIS-K-2548 was 118 ° C, and the average molecular weight was 6,500.

Synthesis Example 5 109 g (1.0 mol) of p-aminophenol as an aromatic amine compound represented by the general formula (III) and α, α′-as an aralkyl alcohol derivative represented by the general formula (IV) in a reaction vessel. Diacetoxy-p-xylene 110.2 g (0.
5 mol), 6.8 g of zinc chloride as a catalyst (0.05 mol) and p
-Toluenesulfonic acid 19 g (0.1 mol) was charged and the reaction was carried out under reduced pressure by a water-jet pump. The reaction started at around 130 ° C and was heated up to 170 ° C in 3 hours. On the way, acetic acid produced was collected by a cryogenic trap. After holding at the same temperature for 3 hours, the reaction temperature was further raised to 200 ° C., and aging was carried out at 200 to 210 ° C. for 1 hour to finish. After cooling to 95 ° C., 300 ml of toluene was added and dissolved with stirring. To this was added 20.2 g of triethylamine, 200 ml of water was added, and the mixture was stirred and allowed to stand to remove the lower aqueous layer by liquid separation. Once again, water
After separation with 200 ml of water and separation in vacuo, toluene and unreacted p-aminophenol were removed. As a residual brown resin thus obtained, 138 g of a co-condensation resin of p-aminophenol was obtained.

The amine equivalent of the aromatic amino resin obtained as described above is
It was 0.525, the softening point measured by the ring and ball softening point measuring device according to JIS-K-2548 was 94 ° C, and the average molecular weight was 2,200.

Synthesis Examples 6 to 14 Types of aromatic amine compounds represented by the general formula (III),
The reaction was performed in the same manner as in Synthesis Example 1 except that the type and amount of the aralkyl alcohol derivative represented by the general formula (IV), the type and amount of the catalyst, and the reaction conditions were as shown in Table 1.
Various aromatic amine resins as shown in (4) were obtained.

Examples 1 to 4 Each of N, N'-4,4'-diphenylmethane bismaleimide and the aromatic amine resin 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. -2 in the parts by weight shown in Figure 2 and melted by heating at 180 ℃ for 20 minutes, degassing at 150 ℃ under reduced pressure (10-15mmHg) for 30 minutes, then cool to room temperature, brown transparent A resin composition solidified into a glass 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 a primary molded product, and further in an oven at 250 ° C. Post cure for 4 hours, length 127mm, width 12.7mm, thickness
A test piece of a 6.4 mm cured product was obtained.

The heat distortion temperature of this test piece is ASTM-D-648 and the bending test is ASTM
-Procedure according to D-790, and in addition, in air, heating temperature 10 ℃ / m
When the thermal decomposition initiation temperature in in was measured, the results shown in Table 2 were obtained.

Examples 5-17 and Comparative Examples 1-2 Using 100 parts by weight of N, N'-4,4'-diphenylmethane bismaleimide and the aromatic amine resin shown in Table 2 by weight, The same operation as in Examples 1 to 4 was performed, and the results shown in Table 2 were obtained.

Comparative Example 3 N, N'-4,4'-diphenylmethane bismaleimide and 4,
The same operations as in Examples 1 to 4 were carried out except that 4 parts by weight of 4'-diaminodiphenylmethane shown in Table 2 was used, and the results shown in Table 2 were obtained.

Comparative Example 4 Instead of the resin composition of the present invention, Kelimide-1050 (manufactured by Nippon Polyimide Co., Ltd., Polyamino bismale) Molded products were prepared in the same manner as in Examples 1 to 4 by using the (mid resin), and various physical properties were measured. The results are shown in Table-2.

From the results of Table-2, the thermosetting resin composition according to the present invention has a high bending strength and bending elastic modulus, a heat distortion temperature of 290 ° C or higher,
Excellent thermal resistance with thermal decomposition starting temperature of 340 ℃ or higher.

〔The invention's effect〕

INDUSTRIAL APPLICABILITY The thermosetting resin of the present invention has excellent mechanical strength and heat resistance, and is expected to be widely used in the electric and electronic fields, which are required to have higher heat resistance in recent years, and mechanical fields such as aircraft and vehicles. The industrial use effect is great.

Claims (1)

[Claims] 1. A formula (I) 100 parts by weight of N, N'-4,4'-diphenylmethane bismaleimide represented by and the aromatic compound represented by the formula (II) (II) (In the formula, A represents a phenylene group, an alkyl-substituted phenylene group, a diphenylene group, a diphenyl ether group or a naphthylenyl group, and R ¹ is a halogen atom, 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 R ¹ may be the same or different from each other and may form a ring, L represents 1 or 2, m represents an integer of 0 to 3, and n represents 0 to 300. A thermosetting resin composition comprising 5 to 100 parts by weight of an amine resin.