KR930002005B1 - Thermosetting resin composition for molding - Google Patents

Abstract

The thermosetting resin compsn. comprises (a) 20-60 wt. parts of a modified bismaleimide resin obtd. by the addition reaction of a monomaleimide of formula (I) ?x = carboxyl, hydroxyl or amine gp.? having a functional gp. and a bixphenol A type epoxy resin, (b) 40- 80 wt. parts of an inorganic filler, (c) 0.8-25 wt. parts of a silicon oil, and (d) 0.5-5.0 wt. parts of a mixed caalyst composed of an organic peroxide and an imidazole deriv. The inorganic filler is pref. silicon oxide, calcium carbonate, alumina, silica, glass fiber graphite and/or mica. The thermosetting resin has a good moldability, heat-resistance and mechanical strength.

Description

Thermosetting resin composition for molding

The present invention relates to a thermosetting resin composition based on a bismaleimide compound, and more particularly, to a thermosetting resin composition for molding having excellent moldability and heat resistance, low molding shrinkage ratio, 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 bismaleimide compound-based resin molding materials is rapidly increasing, particularly for parts requiring high temperature heat resistance.

However, most of the bismaleimide-based resin molding materials have high curing temperatures in molding processability, too long molding time, and have practical problems, and have high heat resistance and very low toughness. There is this. In general, the cured product produced by copolymerization with only the short molecular chain of mismaleimide itself has high crosslinking density, and thus exhibits high heat resistance at pyrolysis temperature of 430 ° C. or higher, while lacking plasticity and low toughness. It has a big disadvantage that it melts only in high boiling point polar solvents such as N, N'-dimethylformamide (DMF, bp 153 ° C) and N-methyl-2-pyrrolidone (NMP, bp 202 ° C).

The Kinel series developed by Rhone Poulenc, a representative bismaleimide resin molding material that is currently commercialized, is a bismaleimide N, N'-4,4'-diphenylmethanebismaleimide. Thermosetting for molding a polyamine bismaleide (PABM) prepolymer having a molecular weight of about 1000 synthesized by Michael addition reaction of 4,4'-diaminodiphenylmethane, a primary diamine, with an inorganic filler and other additives. Resin composition.

In this case, the primary diamine is added to the bismaleimide to increase the molecular weight of the prepolymer, resulting in lower crosslinking density when cured, resulting in somewhat lower heat resistance but somewhat toughness.

However, the polyamine bismaleimide has undergone some crosslinking reaction when the bismaleimide and the primary diamine form Michael addition reaction at low temperature to form a low molecular weight prepolymer, which is still a high boiling point polar solvent N-methyl-2-pyrrolidone. It is soluble only in the back and can be formed by itself, but it requires long time heating at high temperature. In order to improve this, a method of using an organic peroxide as a curing accelerator is widely known, but in this case, a gas (Gas) is generated during molding, thereby reducing the appearance of the molded article.

In order to solve this problem in the present invention, by using a bismaleimide prepolymer having a new structure in which a monomaleimide having a functional group and a bisphenol-A epoxy resin are reacted, the pot life is maintained while maintaining the heat resistance of the bismaleimide. It can be greatly improved, and can be processed without using a solvent, and by changing the molecular chain length of bisphenol A epoxy resin, it is possible to freely adjust the molecular weight and viscosity of the synthesized prepolymer, so that it can be compressed and injected. Various molding methods, such as transfer molding, can be diversified, and since the flowability is very good, the amount of filler can be increased to produce a composition which is economical.

In addition, the second feature of the present invention is that by using the organic peroxide and the imidazole derivative together as a curing accelerator, by suppressing the gas generated by the organic peroxide during molding, the appearance characteristics of the final molded article is excellent.

This is because imidazole not only has an excellent effect as a curing accelerator but also achieves an optimal curing state by controlling the thermal decomposition side effects of the organic peroxide by controlling the use ratio of organic peroxide and imidazole.

In addition, in the present invention, the silicone oil is used to improve the toughness while maintaining the heat resistance as it is, and to reduce the molding shrinkage rate.Since the silicone oil has a low surface energy and a nonpolar structure, it is collected on the contact surface with air and has high hydrophobicity. The formation of the surface having the structure also improved the moisture resistance.

That is, the present invention is a molding thermosetting resin composition

1) 20 to 60 parts by weight of a modified bismaleimide resin obtained by addition reaction of a monomaleimide having a functional group with a bisphenol A epoxy resin

2) 40 to 80 parts by weight of inorganic filler

3) 0.8-25 parts by weight of silicone oil

4) 0.5 to 5.0 parts by weight of a mixed catalyst consisting of organic peroxide and imidazole.

The modified bismaleimide resin of component 1) used in the present invention is a bismaleimide prepolymer obtained by the addition reaction of a monomaleimide having a functional group and a bisphenol A epoxy resin as a component used only in the present invention. The molecular weight is 600-1800, the softening point is 40-110 degreeC, Preferably it is 800-1100, and the softening point is 60-80 degreeC.

등이며, R₁, R₂, R₃, R₄, R₅, R₆, R₇, R₈은 각각 같거나, 다를 수 있으며, 저급알킬기이고, n은 0에서 4까지의 정수를 나타낸다.Where X is

And R ₁ , R ₂ , R ₃ , R ₄ , R ₅ , R ₆ , R ₇ , and R ₈ may be the same or different, respectively, a lower alkyl group, and n represents an integer from 0 to 4.

It is appropriate to use the amount of 20 to 60 parts by weight per weight of the precursor composition. If the amount is 20 parts by weight or less, molding is difficult due to the deterioration of fluidity, and if it is 60 parts by weight or more, physical properties such as mechanical properties and moisture resistance are reduced.

The monomaleimide which has a functional group used for the synthesis | combination of modified bismaleimide resin which is 1) component in the composition of this invention is a substance represented with the following general formula (II).

In Formula (II), X represents a carboxyl group, a hydroxyl group, or an amine group.

Specific examples include 3-maleimido benzoic acid, 4-maleimido benzoic acid, 3-maleimido phenol, 4-maleimido phenol, 3-maleimido aniline, 4-maleimido aniline, 3-maleimido-N-methylaniline, 4 -Maleimido-N-methylaniline and the like.

In addition, the bisphenol-A epoxy resin used for the synthesis of the modified bismaleimide resin of component 1) is an epoxy resin having an epoxy equivalent of 170 to 700 and contains at least two or more epoxy groups in one molecule. Increasing the crosslinking density of the resulting modified bismaleimide resin results in a decrease in processability and a decrease in toughness of the final molded article, and in the case of 700 or more, a rapid decrease in heat resistance is accompanied.

Synthesis of modified bismaleimide resins involves the addition of known catalysts (BSRAO, JPS, 1988) and the addition of a catalyst and heating under a nitrogen atmosphere to further react the functional groups of epoxy groups and monomaleimide. In addition, there is an advantage in that a stable B-stage compound can be obtained when a catalyst is not used due to processing characteristics. The synthesis method of the modified bismaleimide of the present invention will be described in detail as follows.

After mixing monomaleimide which has a functional group, and an epoxy resin of bisphenol-A type in an equivalence ratio, it stirred vigorously, heating at 185-200 degreeC. Nitrogen was refluxed to prevent oxidative degradation of the epoxy resin during the reaction, and after confirming that the contents were a clear solution, the properties of the epoxy resin appeared at ν = 910 cm ^-1 and δ = 2.8 ppm of FT-IR and NMR, respectively. The reaction is terminated when the peak disappears completely. The modified bismaleimide resin in the molten state is poured into an aluminum dish, cooled to room temperature, and then ground in a mortar to obtain a brown modified bismaleimide resin powder.

On the other hand, the inorganic filler of the 2) component used in the present invention is specifically silicon oxide, calcium carbonate, alumina, molten silica, crystalline silica, glass fiber, carbon fiber, graphite, magnesite, gypsum, graphite, tar, mica, Silica sand, kaolin, aluminum hydroxide, asbestos, molybdenum sulfide, and the like, and these may be used alone or in combination of two or more thereof. The amount of the inorganic filler used is 40 to 80 parts by weight based on 100 weight parts of the total resin composition, and when used at 40 parts by weight or less, the coefficient of thermal expansion increases, so that in the case of a sealing device, physical properties such as heat resistance, crack resistance, and moisture resistance decrease. When using more than a weight part, fluidity falls 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, dimethyl silicone oil. Or methylphenyl silicone oil or the like may be used in which the characteristics of these silicone oils are slightly changed. Specifically, polydiorganosiloxane oil, fluorosilicone oil, silicone polyester copolymer oil, alkyl modified silicone oil, fatty acid modified silicone oil, amino modified silicone oil, epoxy modified silicone oil, and the like, 25 ° C.), the viscosity is preferably 500 to 1,000,000 cps. In particular, amino modified silicone oil having an amine function is most 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 to 25 parts by weight, and preferably 1.5 to 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 for molding according to the present invention is obtained by using the above-mentioned components 1), 2) and 3) as essential components and by using a curing accelerator for the purpose of lowering the curing temperature during molding and shortening the curing time. .

In the present invention, when dicumyl peroxide (DCP) is used alone as an organic peroxide, it is excellent as a curing accelerator, but the imidazole compound to prevent the gas generated by pyrolysis during molding to damage the appearance of the molded article. It was used in parallel with.

Specific examples of the organic peroxides used in the present invention include benzoyl peroxide (BPO), dicumyl peroxide (DCP), di-tert-butyl peroxide (DTBP), α, α'-bis (tert-butylperoxy propyl) benzene , 4,4'-di-tert-butyl peroxy-n-butyl valerate, 1,1'-di-tert-butylperoxy-3,3'-5-trimethyl cyclohexane, and the like as an imidazole compound Is imidazole, 2-methyl imidazole, 1,2-dimethylimidazole, 2-phenylimidazole, 2-ethylimidazole, 2-ethyl-4-methylimidazole, 2-methyl-4- Phenylimidazole, 2-undecyl 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 whole resin compositions.

When the total amount of the curing accelerator is less than 0.5 parts by weight, the curing speed 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.

Further, in the present invention, as an additive, a release agent such as a pigment such as 0.1 to 5.0 parts by weight of carbon black and the like, stearic acid, zinc stearate, natural wax, higher fatty acids and metal salts thereof, and paraffin in the range of 0.1 to 5.0 parts by weight. Coupling agents such as epoxysilane, vinylsilane, aminosilane, borane compound, alkoxy titanate compound, and aluminum chelate compound in the range of 0.1 to 5.0 parts by weight were used. In addition, the manufacturing method of the thermosetting resin composition for shaping | molding in this invention is demonstrated in detail as follows.

Each of the above-mentioned components are uniformly mixed using a kneader such as a Henschel mixer, then melt-kneaded with a heating roller, a brabender, an extruder, or the like, followed by compounding the B-staged resin composition. It can be cooled and finely pulverized to form a powder or refined form.

The resin composition of the bismaleimide compound of the present invention is not only excellent in moldability, but also excellent in heat resistance and mechanical strength of the final molded article, and has a low coefficient of thermal expansion, a molding shrinkage ratio, and the like, and is excellent in appearance.

Hereinafter, the present invention will be described in detail by production examples, examples and comparative examples.

[Production Example 1]

To a three-necked flask equipped with a stirrer, a thermometer and a nitrogen inlet are added 21.7 g of 3-maleimido benzoic acid and 19 g of diglycidyl ether (LER 850, LUCKY) of bisphenol A having an epoxy equivalent of 190.

Subsequently, stirring was continued with a stirrer while maintaining 185 ° C. for 45 minutes to confirm that the solution became a clear solution. The solution was poured into an aluminum dish, cooled to room temperature, and then pulverized in a mortar to obtain a yellowish-brown glossy powder.

Hereinafter, this powder is called modified bismaleimide A. The 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]

Except for using 3-maleimido benzoic acid instead of 3-maleimido benzoic acid in Preparation Example 1 was carried out in the same manner as Preparation Example 1 to obtain a reddish brown glossy powder, which is referred to as modified bismaleimide resin B hereinafter The same test as in Preparation Example 1 was conducted, and the results are shown in Table 1.

[Manufacture example 3]

A powder was obtained in the same manner as in Preparation Example 1, except that 18.9 g of 3-maleimido phenol was used instead of 3-maleimido benzoic acid in Preparation Example 1, and the powder was hereinafter referred to as modified bismaleimide C. The same test as in 1 was carried out and the results are shown in Table 1.

[Production Example 4]

A powder was obtained in the same manner as in Preparation Example 1, except that 18.9 g of 4-maleimido phenol was used instead of 3-maleimido benzoic acid in Preparation Example 1, and the powder was hereinafter referred to as modified bismaleimide D. The same test as in 1 was carried out and the results are shown in Table 1.

Production Example 5

Preparation Example 1 except that 47.5g of diglycidyl ether of bisphenol A (LER 1050, LUCKY) having an epoxy equivalent of 475 was used instead of diglycidyl ether of bisphenol A having an epoxy equivalent of 190. The same procedure was followed to obtain a yellowish brown powder, which is hereinafter referred to as modified bismaleimide E, and was subjected to the same test as in Preparation Example 1, and the results are shown in Table 1.

[Manufacture example 6]

47.5 g of diglycidyl ether of bisphenol A with epoxy equivalent of 475 instead of diglycidyl ether of bisphenol A with epoxy equivalent of 190 instead of 3-maleimido benzoic acid in Preparation Example 1 Except for using the same as in Preparation Example 1 to obtain a reddish brown powder, this powder is referred to as modified bismaleimide F below, the same test as in Preparation Example 1 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 25 ° C.), dicumyl peroxide (DCP) as a curing accelerator, 1.0 Parts by weight, 0.5 parts by weight of 2-ethyl-4-methylimidazole, 1.0 part by weight of 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 Evenly blended.

The mixture is melt kneaded in a Brabender preheated to 80-110 ° C. for about 10 to 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 pressure is applied to 50 kg / cm 2.

After holding for about 1 hour at this condition, the mold is removed at a high temperature, and then the secondary curing is performed at 260 ° C. for 4 hours.

The moldings thus obtained were measured for mechanical and thermal properties in accordance with their respective test standards. The results and molding characteristics during molding are shown in Table 2. As an example, the flexural strength test may be performed after fabricating a specimen according to the ASTM D790-71 standard for flexural test, and measuring the measured value at room temperature (25 ° C) at 50 mm span and heating at 200 ° C for 500 hours. 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 in Example 1, 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 30 parts by weight of the modified bismaleimide resin C was used instead of 30 parts by weight of the modified bismaleimide resin A in Example 1, and the same physical properties and molding properties were obtained. The measurement results are shown in Table 2.

Example 4

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

Example 5

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

Example 6

A composition was prepared in the same manner as in Example 1, except that 30 parts by weight of the modified bismaleimide resin F 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 7

A composition was prepared in the same manner as in Example 1 except that the amount of the modified bismaleimide resin A used in Example 1 was 26 parts by weight, and 44 parts by weight of glass fiber and 22.5 parts by weight of fused silica were used as the inorganic filler. The physical properties and molding properties were measured by the method, and the results are shown in Table 2.

Example 8

Except for using the modified bismaleimide resin A in Example 1 to 20 parts by weight, and 71.5 parts by weight of molten silica as an inorganic filler, the blending ratio of the other composition is the same as in Example 1, by tableting the composition powder obtained After preheating with a high frequency preheater, it is injected into a mold at 175 ° C with a transfer pressure of 25 to 100kg / cm ² using a low pressure transfer molding machine, and then molded for 5 minutes and then taken out of the mold for 4 hours at 240 ° C. Harden. Hereinafter, the physical properties and molding properties were carried out in the same manner as in Example 1 and the results are shown in Table 2.

Comparative Example 1

N, N'-4,4'-diphenylmethanebismaleimide and 4,4'-diaminodiphenylmethane were substituted for 30 parts by weight of modified bismaleimide resin A and 5 parts by weight of amino-modified silicone oil in Example 1. A composition was prepared in the same manner as in Example 1, except that polyamino bismaleimide prepolymer (Kerimid 601, Rhone-Poulence product name) synthesized at a molar ratio of 2.5: 1 was used to carry out the same evaluation test as in Example 1. The results are shown in Table 2.

Comparative Example 2

A composition was prepared in the same manner as in Example 1, except that 1.5 parts by weight of dicumyl peroxide alone was used in place of the mixed catalyst system of dicumyl pioxide and imidazole as a curing accelerator. The same evaluation test was carried out and the results are shown in Table 2.

Comparative Example 3

A composition was prepared in the same manner as in Example 1, except that 5 parts by weight of the modified bismaleimide resin A was used instead of 5 parts by weight of the amino modified silicone oil in Example 1, and the same evaluation test as in Example 1 was conducted. Is shown in Table 2.

TABLE 2

As shown in Table 2, it can be seen that the composition using the novel modified bismaleimide resin of the present invention has excellent moldability and excellent appearance characteristics of the final cured product, and mechanical properties and heat resistance are typical addition bismaleimide resin compositions. Since the thermal expansion coefficient, water absorption rate, and mold shrinkage rate are very close to the (Kinnel series), it can be used as structural materials, high heat resistant parts, or semiconductor encapsulation materials for automobiles and aircrafts.

Claims (7)

1) 20 to 60 parts by weight of modified bismaleimide resin obtained by addition reaction of monomaleimide having a functional group and bisphenol A epoxy resin, 2) 40 to 80 parts by weight of inorganic filler, 3) 0.8 to 25 parts by weight of silicone oil 4) A thermosetting resin composition for molding, comprising 0.5 to 5.0 parts by weight of a mixed catalyst composed of an organic peroxide and an imidazole derivative. The thermosetting resin composition for molding according to claim 1, wherein the resulting modified bismaleimide resin has a molecular weight of 600 to 1800 and a softening point of 40 to 110 ° C. The thermosetting resin composition for molding according to claim 1, wherein the monomaleimide having a functional group is represented by the following general formula (II).

In the formula, X is a carboxyl group, hydroxyl group, or amine group. 2. The molding thermosetting resin composition according to claim 1, wherein the bisphenol A epoxy resin contains two or more epoxy groups in one molecule with an epoxy equivalent of 170 to 700. The inorganic filler according to claim 1, wherein the inorganic filler is silicon oxide, calcium carbonate, alumina, molten silica, crystalline silica, glass fiber, carbon fiber, graphite, gypsum, graphite, tar, mica, silica sand, kaolin, aluminum hydroxide, asbestos, sulfide A molding thermosetting resin composition comprising molybdenum alone or in combination of two or more thereof. The molding thermosetting resin composition according to claim 1, wherein the silicone oil has an amine functional group and has a viscosity of 500 to 1,000,000 cps at 25 ° C. The molding thermosetting resin composition according to claim 1, wherein the use ratio of the organic peroxide and the imidazole derivative in the mixed catalyst is 1: 5 to 5: 1.