JPS6154820B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a thermosetting resin composition for molding that has excellent heat aging resistance and thermal stability. the current,
Thermosetting resin molding materials are used in fields that require heat resistance, such as electronic parts, automobiles, and mechanical parts. Among these, thermosetting polyimide resin molding materials are used for parts that require a particularly high degree of heat resistance. is starting to be used. However, the long-term heat resistance is insufficient, and improving the heat resistance results in a decrease in toughness, which is a dissatisfaction. For example, a cured product produced by bisimide homopolymerization has a high thermal decomposition temperature of 437° C. and is excellent in heat resistance, but its major drawback is that it has poor flexibility and lacks toughness due to its high crosslinking density. It is also known (for example, as described in Japanese Patent Publication No. 48-24835) that heat resistance and toughness can be improved by incorporating an effective amount of bisimide into a monoimide polymer. However, even though the toughness has been improved, it is still insufficient. According to Japanese Patent Publication No. 45-34834, a monoimide is copolymerized to a bisimide polymer and a flexibility imparting agent is added as a means of imparting flexibility, but the application is for casting and heat resistant. I am still dissatisfied with my sexuality. Furthermore, it is well known that organic peroxides such as dicumyl peroxide are conventionally used as curing agents for polyimide resins, but when organic peroxides are used, gas is generated during molding and molding It has the drawback of deteriorating the appearance of the product and causing mold fogging. The present inventors have found that by mixing an effective amount of polyamino bismaleimide prepolymer into bisimide and using an organic peroxide and imidazole together as a curing agent, the material has better heat resistance and thermal stability than conventional polyimide resin molding materials. It has been found that a molding material with excellent gloss and no mold fogging can be obtained. According to the present invention, by using bisimide, which has a longer molecular chain than monoimide, and a polyaminobisimide prepolymer, which has a longer molecular chain than bisimide, the crosslinking density of the cured product is lowered, resulting in flexibility and significantly improved toughness. Ru. The ratio of bisimide and polyamino bismaleimide prepolymer is not particularly limited, but when both heat resistance and toughness are required, 50 to 90 weight percent of the polyamino bismaleimide prepolymer is added to the bisimide based on the total weight of the resin composition, or For purposes that do not require high toughness but only require heat resistance, it is preferable to add 20 to 50 percent by weight. The thermal decomposition temperature of such a resin composition is 373 to 434°C, which is higher than the thermal decomposition temperature of polyimide resin, 364°C, and a major feature is that it has excellent heat resistance in any mixing range. Furthermore, the resin composition obtained by the present invention has excellent curability and moldability that can be sufficiently molded under conventional molding conditions for thermosetting materials by using an organic peroxide and imidazole as a curing agent in combination. . Furthermore, conventionally, organic peroxides such as dicumyl peroxide have been used alone as curing agents for polyimide resins, but during molding, these organic peroxides undergo unnecessary decomposition mechanisms and generate gas. This causes a deterioration in the appearance of the molded product. For example, in the case of dicumyl peroxide The thermal decomposition mechanism is assumed to be the following: decomposed gases of acetophenone and ethane are generated, and these decomposed gases cause deterioration of the appearance of the molded product during formation. In contrast, according to the present invention, 0.1 to 10% by weight of peroxide is added to the resin component, and furthermore, the general formula (However, R is hydrogen, a C ₁ to C ₁₉ alkyl group, or an aromatic organic group)
It has been found that when used in combination with 0.05 to 5% by weight, no gas is generated during molding, the appearance of the molded product is good, and the imidazole compound also has a remarkable effect as a curing accelerator. This is considered to be because the imidazole compound has the effect of suppressing unnecessary thermal decomposition of the organic peroxide. In the present invention, bisimide is defined by the general formula

[Formula] (where R ₁ is hydrogen or a C ₁ to C ₁₀ alkyl group, R ₂ is a divalent organic group having at least one aromatic nucleus)
N.N'-bisimide represented by, for example, N.N'-m-phenylene bismaleimide, N.
N'-4,4'-diphenyl ether bismaleimide, N,N'-p-phenylene bismaleimide,
N・N′-4・4′-diphenylmethane bismaleimide, N・N′-m-xylene bismaleimide,
N・N′-p-xylene bismaleimide, N・
N'-diphenylcyclohexane bismaleimide, N.N'-4.4'-diphenylsulfon bismaleimide, N.N'-4.4'-diphenyl-1.
Examples include 1-propane bismaleimide, and one or more of them can be used. or,
Polyamino bismaleimide prepolymer has the general formula

[Formula] Bismaleimide and the general formula H ₂ N−R ₂ −
It is a prepolymer obtained by an addition reaction with a diamino compound represented by NH ₂ (where R ₂ is a divalent organic group having at least one carbon atom). Examples of organic peroxides include benzoyl peroxide, dicumyl peroxide, t-butyl peroxide, di-t-butylperoxydiisopropylbenzene, etc., and imidazole compounds include 2
- Methylimidazole, 2,4,5-triphenylimidazole, 2-methyl-4-ethylimidazole, etc., and the amount of peroxide and imidazole compound added is 0.1 per 100 weight percent of the two imide components. -10 weight percent, imidazole compound 0.05-5 weight percent. The filler components used in the present invention include heat-stable silica powder, aerosil, alumina powder, calcium silicate powder, aluminum hydroxide powder, copper powder, glass powder, mica powder, asbestos fiber, graphite, and glass. Inorganic or organic materials such as fibers, carbon fibers, and synthetic fibers. The proportion of the filler component is not particularly limited, but is preferably in the range of 50 to 500 parts per 100 parts of the resin component. Furthermore, 0.1 to 5.0 weight percent of a pigment such as carbon black, and 0.1 to 5.0 weight percent of a mold release agent such as stearic acid, zinc stearate, and montana wax may be included based on the filler component. The molding composition of the present invention can be used in rolls, co-kneaders,
It is obtained by melt-kneading at a temperature of 150°C or less using a Henschel mixer, extruder, etc., followed by cooling and pulverization. The molding composition obtained by this method cannot be molded with sufficient thermal rigidity unless molded with conventional polyimide resins at 180°C to 200°C for 5 to 10 minutes. The composition according to the invention is 160
Molded products with sufficient thermal rigidity can be obtained at ~180°C for 1 to 3 minutes, and are characterized by superior heat resistance and moldability compared to conventional polyimide resins. The method of the present invention will be explained in more detail below using Examples and Comparative Examples. Comparative Example 1 4 moles of N.N'-4.4'-diphenylmethane bismaleimide (hereinafter abbreviated as BMI-1) and 1 mole of 4.4'-diaminodiphenylmethane were thoroughly mixed,
The mixture is then heated to 150°C for 15 minutes. After cooling, the prepolymer is finely pulverized to determine the weight average molecular weight.
A polyaminobisimide prepolymer (hereinafter abbreviated as PI) of 1100 was obtained. Table 1 shows the weight loss rate of this prepolymer at a thermal decomposition temperature of 500°C. Comparative Example 2 Using the PI obtained in Comparative Example 1, it was mixed with filler components at the blending ratio shown below, and after roll-kneading with rolls at 100°C for 10 minutes, the sheet was cooled and powdered with an impact pulverizer.

[Table] Tables 2 and 3 show the moldability of this composition and the heat resistance properties of the molded product. There was gas clouding on the surface of this molded product, and cavities were formed in the molded product, resulting in poor molded product properties. Example 1 BMI-1 and 2 mol of BMI-1 were mixed with 1 mol of 4,4'-diaminophenylmethane, and then the mixture was heated at 150°C for 15 minutes. They were mixed in the proportions shown in Table 1, 1% by weight of dicumyl peroxide and 0.7% by weight of 2-methylimidazole were added to the total weight of the two maleimides, and cured at 165°C. Table 1 shows the thermal decomposition temperature and weight loss rate at 500°C when this cured product was heated in air at a heating rate of 5°C/min.

[Table] As shown in Table 1, by reducing the amount of PI added to BMI-1, the thermal decomposition temperature becomes higher.
Weight loss rate is decreasing. Example 2 BMI-1, the PI used in Example 1, and the filler components were mixed in the proportions shown in Table 2, and after roll kneading for 30 minutes with rolls at 120°C, the sheet was cooled and subjected to an impact crusher. It was powdered.

【table】

[Table] The material obtained in Comparative Example 2 has a temperature of 5 to 10 at 180-200℃.
However, the material obtained according to Example 2 had a molding condition of 165 min.
A molded article with sufficient thermal rigidity was obtained by molding at ~180°C for 3 minutes. The properties of this molded article are shown in Table 2. Compared to Comparative Example 2, the molded article has no cloudiness, has good curability, and has a remarkable effect of the combined use of peroxide and imidazole compound. Examples 3 to 8 Fillers and other additive components were the same as in Example 2, the same formulation was used, various N・N′-bisimides were used,
Materials were obtained by mixing resin components in the proportions shown in Table 3.

[Table] With the materials of Examples 3 to 8, molded products with sufficient thermal rigidity can be obtained by molding at 165 to 180°C for 3 to 5 minutes, and due to the combined effect of the peroxide and imidazole compound, during molding, A molded product with an excellent appearance and no gas generation was obtained.

Claims (1)

[Claims] 1 General formula [Formula] (where R ₁ is hydrogen or a C ₁ to C ₁₀ alkyl group, R ₂ is a divalent organic group having at least one aromatic nucleus)
For molding, the bisimide represented by the above, a polyamino bismaleimide prepolymer, a peroxide, an imidazole compound, and a filler component are melt-kneaded at a temperature of 150°C or lower, then cooled to solidify, and then crushed. A method for producing a thermosetting resin composition. 2 General formula The bisimide represented by is N・N′-4・4′-diphenylmethane bismaleimide, N・N′-4・4′-
Diphenyl ether bismaleimide, N・N'-
Claim 1 is at least one selected from the group consisting of m-phenylene bismaleimide.
A method for producing a thermosetting resin composition for molding as described in 2. 3 A polyamino bismaleimide prepolymer is obtained by an addition reaction between bismaleimide and a diamino compound, and has the general formula The thermosetting resin composition for molding according to claim 1 or 2, wherein n is a number of 1 or more, and R ₂ is a divalent organic group having at least one aromatic nucleus. manufacturing method. 4 General formula Claims 1, 2 or 2 consist of 0.1 to 10 weight percent of peroxide and 0.05 to 5 weight percent of imidazole compound based on 100 weight percent of the component consisting of bisimide and polyamino bismaleimide prepolymer represented by 3. A method for producing a thermosetting resin composition for molding according to item 3. 5 General formula Claims 1, 2, 3, or 4 comprising 50 to 500 weight percent of the filler component based on 100 weight percent of the component consisting of bisimide and polyamino bismaleimide prepolymer represented by A method for producing a thermosetting resin composition for molding. 6 N・N′-bisimide means N・N′-4・4′-
Diphenylmethane bismaleimide, N・N'-
4,4'-diphenyl ether bismaleimide,
Claims 1 and 2 are N.N'-4.4'-diphenylsulfon bismaleimide, N.N'-m-phenylene bismaleimide, and N.N'-m-xylene bismaleimide. 2nd term, 3rd term, 4th term
5. A method for producing a thermosetting resin composition for molding according to item 5.