KR900005205B1 - Thermosetting resin composition for molding - Google Patents

Abstract

Thermosetting Resin compsn. for moulding comprises: 20-60 pts. wt. of modified bismaleimide resin obtd. by addition- reaction of aromatic primary or secondary diamine with bismaleimide having 600-1600 molecular wt. and 40-110≰C softening temp.; 40-80 pts. wt. of inorg. filler; 0.8-25 pts. wt. of silicone oil; and 0.5-5.0 pts. wt. of the mixed catalyst comprising org. hydroperoxide and imidazole deriv. Pref. the modified maleimide resin is obtd. by michael addition reaction of bismaleimide with aromatic primary or secondary diamine of 1.2:1-10:1 mol. ratio.

Description

Thermosetting Resin Composition for Molding

The present invention relates to a thermosetting resin composition of an unsaturated bismaleimide compound type, and more particularly, to a thermosetting resin composition for molding having excellent moldability and heat resistance, low molding shrinkage and excellent appearance characteristics.

Currently, thermosetting resin molding materials are used in fields requiring heat resistance, such as electronic parts, automobiles, and mechanical parts. Among them, the use of unsaturated bismaleimide compound-based resin molding materials is rapidly increasing, particularly for parts requiring high temperature heat resistance.

However, in terms of molding processability, the curing temperature is too high, the molding time is too long, a problem arises in practical terms, and if the long-term heat resistance is poor and the heat resistance is improved, the toughness is reduced.

In general, the cured product produced by copolymerization using only bismaleimide itself has high cross-linking density, and thus exhibits high heat resistance at pyrolysis temperature of 430 ° C. or higher, while lacking plasticity and low toughness, N, It has a large defect that only melts in high boiling point polar solvents such as N'-dimethyl formamide (DMF.bp 153 ° C) and N-methyl-2-pyrrolidone (NMP.bp 202 ° C).

The Kinel series developed by Rhone-Poulenc, a representative unsaturated bismaleimide resin molding material that is currently commercialized, is a bismaleimide N, N'-4,4'-diphenylmethane bis Molding combining polyamine bismaleimide (PABM) prepolymer having a molecular weight of about 1000 synthesized by Michael addition reaction of maleimide with 4,4'-diamino diphenylmethane, a primary diamine, an inorganic filler and other additives It is a thermosetting resin for.

That is, the present invention is a molding thermosetting resin composition 1) 20-60 parts by weight of modified bismaleimide resin in which aromatic primary diamine and aromatic secondary diamine are added to bismaleimide having a molecular weight of 600-1600 and a softening point of 40-110 ° C. 2) 40-80 parts by weight of inorganic filler 3) 0.8-25 parts by weight of silicone oil 4) It is characterized by consisting of 0.5-5.0 parts by weight of a mixed catalyst consisting of organic peroxide and ididazole.

The modified bismaleimide resin of component 1) used in the present invention is an unsaturated bismaleimide prepolymer obtained by Michael addition reaction of bismaleimide with an aromatic primary diamine and an aromatic secondary diamine, which is a component used only in the present invention. 600-1600, softening point is 40-110 degreeC, Preferably molecular weight is 800-1100, and softening point is 60-80 degreeC.

The amount used is preferably 20 to 60 parts by weight per weight of the precursor composition. In the case of 20 parts by weight or less, molding is difficult due to the decrease in fluidity, and in the case of 60 or more, physical properties are lowered.

Bismaleimide used for the synthesis | combination of modified bismaleimide prepolymer of 1) component in the composition used for this invention is a substance represented by the following general formula (I).

Wherein B comprises a double bond between carbon and carbon and represents a divalent group containing at least 2 carbon atoms, preferably 2 to 6 carbon atoms, and A is at least 2 and generally no more than 20 And divalent groups containing carbon atoms.

In this case, the primary diamine is added to the bismaleimide to increase the molecular weight of the prepolymer, and as a result, the crosslinking density is lowered when it is cured, so that the heat resistance is somewhat lowered, but it has some toughness.

However, the polyamine bismaleimide, when the bismaleimide and the primary diamine is Michael addition reaction at low temperature to form a low molecular weight prepolymer, also undergoes some crosslinking reaction, resulting in a high boiling point polar solvent N-methyl-2-pyrrolidone or the like. It dissolves and can be self-molded but requires long time heating at high temperatures. In order to improve the above problems, a method of using an organic peroxide as a curing accelerator is widely known, but in this case, a gas is generated during molding, thereby deteriorating the appearance of the molded article.

In the present invention, by using bismaleimide and secondary diamine to solve such problems, the pot life can be greatly improved by eliminating the disadvantage that the crosslinking reaction proceeds during the Michael addition reaction at low temperature and the viscosity increases rapidly. As a result, it can be used without using a solvent. Also, by controlling the molecular weight and viscosity of the prepolymer synthesized by changing the molar ratio by using the primary diamine and the secondary diamine, compression, injection It is possible to diversify molding such as injection and transfer molding, and because the flow is very good, the amount of filler can be increased and it is economical.

In addition, the second feature of the present invention, by using the organic peroxide and the imidazole derivative as a curing accelerator in combination to suppress the gas (gas) caused by the organic peroxide during molding, the gloss of the molded article is good. This is not only excellent imidazole as a curing accelerator, but also the effect is widely recognized by suppressing the thermal decomposition side effects of the organic peroxide.

In addition, the use of silicone oil can reduce the toughness and molding shrinkage. Specific examples are as follows. N, N'-1,3-phenylene bismaleimide, N, N'-4,4'-diphenylmethane bismaleimide, N, N'-4,4'-diphenylether bismaleimide, N , N'-4,4'-diphenylsulfone bismaleimide, N, N'-3,4'-diphenylsulfone bismaleimide, N, N'-4,4'-dicyclohexylmethane bismaleimide , N, N'-4,4'-dimethylene cyclohexane bismaleimide, N, N'-4,4'-diphenyl cyclohexane bismaleimide, N, N'-1,3-xylene bismaleimide Mid, 2,4-bismaleimide toluene and 2,6-bismaleimide toluene.

The aromatic secondary diamine used in the present invention is a substance represented by the following general formula (II).

Wherein A ′ is at least one aromatic group, generally a divalent group containing up to 20 carbon atoms, and R is an aliphatic group containing at least 1 to 10 carbon atoms.

Specific examples include N, N'-dimethyl-4,4'-diamino diphenylmethane, N, N'-methylethyl-4,4'-diamino diphenylmethane, N, N'-dimethyl-4,4 '-Diamino diphenylsulfone, N, N'-4,4'-diamino diphenylether, N- (1,3-dimethylbutyl) -N'-phenyl-paraphenylenediamine, N-isopropyl- N'-phenyl-paraphenylene diamine, N, N'-diphenyl-paraphenylenediamine, N, N'-diethyl-4,4-diamino toluene, N, N'-dimethyl-2,6- Diamino toluene, N, N'-dicyclohexyl-4,4'-diamino diphenylmethane, and the like.

The aromatic primary diamine used in the present invention is a substance represented by the following general formula (III).

Wherein A ″ is a divalent group containing at least one aromatic group and generally containing up to 20 carbon atoms. Specifically, 4,4'-diamino diphenylmethane, 4,4'-diamino Diphenylether, 4,4'-diamino diphenylmethane, 4,4'-diamino diphenylether, 4,4'-diamino diphenyl sulfonmeta-phenylene diamine, para-phenylene diamine 2,4 -Diamino toluene, 2,6-diamino toluene, and the like.

In addition, the amount of bismaleimide and aromatic diamine used to synthesize the modified bismaleimide prepolymer is in a molar ratio of 1.2: 1-10: 1, and preferably 1.5: 1-4: 1. The molar ratio of primary diamine and secondary diamine in aromatic diamine and the like is 1: 9-9: 1, preferably 1: 4-4: 1.

When the amount of the aromatic diamine is less than 1.2: 1, the heat resistance is excellent, but moldability and toughness are lowered, and when it is 10: 1 or more, the heat resistance is decreased.

In addition, when the ratio of the primary diamine and the secondary diamine is less than 1: 9, the moldability and water absorption rate are improved, but the mechanical strength is lowered.

On the other hand, as the inorganic filler of the 2) component used in the present invention, specifically silicon oxide, calcium carbonate, alumina, molten silica, crystalline silica, glass fiber, carbon fiber, graphite, magnesite, gypsum, graphite, tar, mica, Silica sand, carotene, aluminum hydroxide, asbestos, molybdenum sulfide, and the like, which may be used alone or in combination of two or more. The amount of the inorganic filler is 40 to 80% by weight based on 100 parts by weight of the total resin composition, and when used below 40% by weight, the coefficient of thermal expansion increases, so that the sealing device has heat resistance, crack resistance, moisture resistance, and the like. The physical properties are lowered, and when used at 80% by weight or more, the fluidity is lowered and molding is difficult.

In addition, the silicone oil of component 3) used in the present invention is formed in a structure in which the unit structure of [-Si-O-] is repeated, and is a compound in a liquid state at room temperature, for example, dimethylsilicone oil or methylphenyl. The silicone oil may be modified in some way, such as polydiorgano siloxane oil, fluoro silicone oil, silicone polyester copolymer oil, alkyl modified silicone oil, fatty acid modified silicone oil, and the like. Roadside silicone oil and epoxy modified silicone oil. In the present invention, the viscosity is preferably 500-1,000,000 CPS at room temperature (25 ° C.), and amino modified silicone oil having an amine functional group is particularly excellent in terms of thermal shock resistance.

The blending ratio of the silicone oil 3) component is generally used in the range of 0.8-25 parts by weight, preferably 1.5-5.0 parts by weight. If the blending ratio is less than 0.8 parts by weight, the effect of improvement such as thermal stress resistance and thermal shock resistance is not sufficient, and when it is 25 parts by weight or more, the workability is reduced.

The thermosetting resin composition of the unsaturated bismaleimide compound of the present invention contains the above-mentioned components 1), 2) and 3) as essential components, and also uses a curing accelerator for the purpose of lowering the curing temperature and shortening the curing time during molding. It was.

In the present invention, the use of dicumyl peroxide (DCP) as an organic peroxide is excellent as a curing accelerator, but is used in parallel with an imidazole compound to prevent damage to the appearance of the molded product due to generation of gas by thermal decomposition during molding. It was.

Specific examples of organic peroxides used in the present invention include benzoyl peroxide (BPO), dicumyl peroxide (DCP), di-tert-butyl peroxide (DTBP), and α, α'-bis (tert-butyl peroxy propyl). Benzene, 4,4'-di-tert-butyl peroxy-n-butyl valerate, 1,1'-di-tert-butyl peroxy-3,3,5-trimethyl cyclohexane, and the like as an imidazole compound. Imidazole 2-methyl imidazole, 1,2-dimethyl imidazole, 2-phenyl imidazole 2-ethyl imidazole, 2-ethyl-4-methyl imidazole, 2-methyl-4-phenyl imidazole 2-unde Thread imidazole and the like. The addition amount of an organic peroxide and an imidazole compound is 0.1-5 weight part of organic peroxides, and 0.05-5 weight part of imidazole compounds with respect to 100 weight part of all resin compositions.

When the total amount of the curing accelerator is less than 0.5 parts by weight, the curing rate is slow, curing does not occur sufficiently, and when the amount is 5 parts by weight or more, the catalyst itself acts as an impurity, thereby deteriorating physical properties.

In addition, in the present invention, as an additive, a release agent such as stearic acid, zinc stearate, natural wax, higher fatty acids and metal salts thereof, and paraffin in the range of 0.1-5.0 parts by weight and pigments such as carbon black and 0.1-5.0 parts by weight based on the filler component. Coupling agents such as epoxy silane, vinylsilane, aminosilane, borane compound, alkoxy thiate compound, aluminum chelate compound in the range of 0.1-5.0 parts by weight were used.

Hereinafter, the manufacturing method of the present invention will be described in detail.

Each composition described above is uniformly mixed using a kneader such as a Henchel mixer, and then melt-kneaded with a heating roller, a brabender, a compressor, or the like to be compounded, and then the B-staged resin composition is prepared. After cooling again, it may be pulverized finely and used in a powder or tablet form.

In addition to excellent moldability of the resin composition of the unsaturated bismaleimide compound of the present invention, the molded article is excellent in heat resistance, mechanical strength, etc., has a low coefficient of thermal expansion, a molding shrinkage ratio, and the like, and has very excellent appearance.

Hereinafter, the present invention will be described in detail by Examples and Comparative Examples.

[Production Example 1]

[Production of Modified Bismaleimide Resin]

5.65 g of N, N'-dimethyl-4,4'-diamino diphenylmethane (0.025 mole) and 14.85 g of 4,4'-diamino-diphenylmethane in a three-necked flask equipped with a stirrer and a thermometer ( 0.075 mole), preheated to 140 ° C., and then 107.4 g of N, N'-4,4'-diphenylmethane bismaleimide (0.30 mole) is added. The temperature is maintained at 140 ° C., the reaction is continued while stirring with a stirrer and confirmed to be a clear solution, followed by degassing while the reaction is continued for about 30 minutes. The mixture is poured into an aluminum dish, cooled to room temperature, and then ground in a mortar to obtain a yellowish brown glossy powder (hereinafter, referred to as "modified bismaleimide resin A").

Softening point and molecular weight of the resin powder were measured using a thermal analyzer and GPC, and the results are shown in Table 1.

Production Example 2-3

The molar ratios of N, N'-dimethyl-4,4'-diamino diphenylmethane and N, N'-diamino diphenylmethane used as aromatic diamine in Preparation Example 1 were changed to 0.5: 0.5 and 0.75: 0.25, respectively. A yellowish brown powder was obtained in the same manner as in Production Example 1, except that this was hereinafter referred to as "modified bismaleimide resin B" and "modified bismaleimide resin C", respectively. The test was carried out and the results are shown in Table 1.

TABLE 1

Example 1

30 parts by weight of modified bismaleimide resin A, 61.5 parts by weight of glass fiber having a length of 3 mm as an inorganic filler, 5 parts by weight of amino-modified dimethyl silicone oil (viscosity 10,000 CPS at 23 ° C.), dicumyl peroxide (DCP) as a curing accelerator. 1.0 part by weight, 0.5 part by weight of 2-ethyl, 4-methyl imidazole, 1.0 part by weight of an amino silane coupling agent ('A1100'-union carbide, trade name), 1.0 part by weight of stearic acid as a release agent and 1.0 part by weight of carbon black as a colorant. Mix uniformly in the mixer.

The mixture is melt kneaded in a Brabender preheated to 80-110 ° C. for about 10-15 minutes, then cooled to room temperature and the resulting composition is finely ground with a grinder. 30 g of the composition thus obtained is placed in a square mold (125 mm x 130 mm x 135 mm), inserted into a press preheated at 200 deg. C, and then pressure is applied to 50 kg / cm < 2 >.

After holding for about 1 hour at the above conditions and removing the mold at a still high temperature, the secondary curing is carried out at 200 ℃ for about 24 hours. Table 2 shows the results of measuring the mechanical and thermal properties of the molded article thus obtained according to each test standard, and the molding characteristics during molding. For example, the flexural strength test may be performed after fabricating a specimen in conformance with the ASTM D790-71 standard for flexural test, and then measuring the temperature at 25 ° C at 50 mm span and heating at 250 ° C for 500 hours. One value was shown and the coefficient of thermal expansion and Tg were measured by TMA.

Example 2

A composition was prepared in the same manner as in Example 1, except that 30 parts by weight of the modified bismaleimide resin B was used instead of 30 parts by weight of the modified bismaleimide resin A, and the same physical properties and molding properties were obtained. The measurement results are shown in Table 2.

Example 3

A composition was prepared in the same manner as in Example 1 except that 26 parts by weight of the modified bismaleimide resin B was used, 44 parts by weight of glass fiber and 22.5 parts by weight of fused silica were used as the inorganic filler. Characteristics and the like are shown in Table 2.

Example 4

Except for using 30 parts by weight of modified bismaleimide resin C instead of 30 parts by weight of modified bismaleimide resin A in the same manner as in Example 1 to prepare a composition and the physical properties and molding properties are shown in Table 2 It was.

Example 5

Except that the amount of modified bismaleimide C used in Example 4 is 30 parts by weight, and 71.5 parts by weight of molten silica is used as the inorganic filler, the blending ratio of the other composition is tableted in the composition powder obtained in the same manner as in Example 4. After preheating with a high frequency preheater, it was injected into the mold at 200 ° C. at a transfer pressure of 25-100 kg / cm 2 using a low pressure transfer molding machine, and then molded for about 2-5 minutes, then taken out of the mold at 220 ° C. Postcure for 24 hours. Hereinafter, physical properties and molding properties were performed in the same manner as in Example 1, and the results are shown in Table 2.

Comparative Example 1

N, N'-4,4'-diphenylmethane bismaleimide and 4,4'-diamino diphenyl instead of 30 parts by weight of modified bismaleimide resin A and 5 parts by weight of amino-modified dimethyl silicone oil in Example 1 Except for using 35 parts by weight of polyamino bismaleimide (PABM) prepolymer synthesized with a methane ratio of 3: 1, the composition was prepared in the same manner as in Example 1 and subjected to the same evaluation test as in Example 1. The results are shown in Table 2.

Comparative Example 2

Except for using 1.5 parts by weight of di cumyl peroxide alone instead of the mixed catalyst system of dicumyl peroxide and imidazole as a curing accelerator in Example 1 to prepare a composition in the same manner as in Example 1 The properties are shown in Table 2.

TABLE 2

Claims (6)

20-60 parts by weight of modified bismaleimide resin in which bismaleimide having a molecular weight of 600-1600 and a softening point of 40-110 ° C. is added and reacted with aromatic primary and secondary diamines, 40-80 parts by weight of inorganic filler, and silicone oil 0.8-25 Molding thermosetting resin composition, characterized in that consisting of 0.5 to 5.0 parts by weight of mixed catalyst consisting of parts by weight and organic peroxide and imidazole derivatives. The molding thermosetting resin composition according to claim 1, wherein the modified bismaleimide resin is subjected to Michael addition reaction of bismaleimide with aromatic primary diamine and aromatic secondary diamine in a molar ratio of 1.2: 1-10: 1. The molding thermosetting resin composition according to claim 1, wherein the aromatic diamine added to the modified bismaleimide resin has a molar ratio of primary diamine and secondary diamine of 1: 9-9: 1. The method of claim 1, wherein the inorganic filler is a silicon oxide, calcium carbonate, alumina, molten silica, crystalline silica, glass fiber, carbon fiber, graphite, gypsum, graphite, tar, mica, silica sand, kaolin, aluminum hydroxide, asbestos alone Or a thermosetting resin composition for molding, characterized in that used in combination of two or more kinds. The molding thermosetting resin composition according to claim 1, wherein the silicone oil has a viscosity of 500-1,000,000 CPS at 25 ° C. with an amine function. The molding thermosetting resin composition according to claim 1 or 5, wherein the use ratio of the organic peroxide and imidazole derivative in the mixed catalyst is 1: 5-5: 1.