JPS5856375B2 - Method for manufacturing thermosetting resin for molding - 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 mechanical properties under heat.

Conventionally, thermosetting resin molding materials have been used for materials that require heat resistance, such as electrical and electronic parts, automobiles, and mechanical parts.
Due to recent advanced technological advances, the conditions for their use have become harsher, and materials with even better heat resistance are required.

Among them, polyimide is a resin with particularly excellent heat resistance.
It is suitable as a material for parts that require heat resistance, dimensional stability, etc., but it has drawbacks in terms of processability.

For example, thermoplastic polyimide is difficult to melt mold and is usually cut after casting and hardening.

In addition, thermosetting polyimide and compositions made by mixing the polyimide with solvents, modifiers, or other components can be melted or laminated, but they require heating at high temperatures for long periods of time, and require precision and high precision molding. It is difficult to mold heat-resistant parts, which has limited the field of application for polyimide resin.

It is known that bisimide and diamine are heated in advance to form a prepolymer and used in this state as a molding material (
For example, it is described in Japanese Patent Publication No. 46-23260).

A composition consisting of polyamino bismaleimide, which is one of the thermosetting polyimide resin materials using such a prepolymer, and a filler has a drawback that it requires a step to form a prepolymer before mixing with the filler. In addition, the molding temperature is particularly high during processing, and molded products can be obtained by heating and curing at 200 to 250 °C, but the fluidity during molding is poor, high pressure is required, and the material handling workability is poor, and precision is difficult. However, there were problems with parts that required heat resistance and those that required molding of a large number of parts.

In order to improve these drawbacks, the present inventors conducted intensive research on resins, curing agents, accelerators, etc., and found that bisimide,
Mixing diamine and peroxide directly with filler 150
By softening and melting kneading at a temperature below ℃, then cooling and solidifying, and then crushing, the resulting composition has excellent fluidity and curability, and the heat resistance of the molded product is also superior to that when using a prepolymer. I found that it was improved.

Conventionally, in order to produce a thermosetting resin composition for molding, for example, phenol, diallyl phthalate, epoxy, bismaleimide, etc. are made into a prepolymer or resin by a condensation or addition reaction, and a filler is added to the prepolymer or resin. In general, it is difficult to directly mix monomers, etc. and fillers to form a molding composition, and there is no such idea with general thermosetting resins, and this kind of thing has not been done in the past. has not been carried out.

According to the present invention, bisimide, diamine and filler are combined into 15
The composition obtained by melt-kneading at a temperature of 0°C or lower has practical moldability, for example, can be molded at a temperature of 150 to 200°C in about 1 to 5 minutes, and the molded and cured product is resistant to mechanical and thermal processing. Excellent characteristics.

This is because bisimide, diamine, etc. are melt-kneaded as monomers during kneading, so the eutectic mixing of bisimide and diamine temporarily lowers the melt viscosity, improving affinity with the filler and improving properties. considered to be a thing.

Although it is possible to melt and knead at a temperature of 150° C. or higher, hardening progresses too much before sufficient mixing occurs, resulting in poor fluidity or difficulty in molding.

To carry out the present invention, the amount of bisimide per mole of diamine is at least 1 mole or more, preferably 1 mole to 10 moles.
Used in the molar range.

If the amount of bisimide is less than 1 mole per mole of diamine, the heat resistance will decrease, and if the amount of bisimide is more than 10 moles, the fluidity will be poor and the molding processability will be extremely poor.

In addition, in the present invention, a prepolymer consisting of bisimide and diamine can be added to the bisimide and diamine components within a range that does not significantly reduce fluidity, and it is also possible to use up to about 50 parts of the prepolymer with respect to the bisimide and diamine components. Preferably it is 20 parts or less.

The bisimide that can be used in the present invention has the general formula (where R1 is hydrogen or an alkyl group of C1 to CIO, R2
is a divalent organic group having at least one aromatic group);
Phenylene bismaleimide, N-N'-4,4'-diphenyl ether bismaleimide, NN/p phenylene bismaleimide, N-N'-4,4'-diphenylmethane bismaleimide, N-N7m xylene bismaleimide, N-N' -p xylene bismaleimide, N-N'-
diphenylcyclohexane bismaleimide, N-N'-
4,4'-diphenylsulfone bismaleimide, N-
One or more types selected from the group such as N'-4.4' diphenyl-1.1 propane bismaleimide can be used.

Diamines represented by the formula (where R is a divalent organic group having at least 2 carbon atoms) include, for example, m-phenylenediamine, p-phenylenediamine, m-xylylenediamine, p-xylylenediamine, 4. One or more selected from 4'-diaminodiphenyl ether, 4,4'diaminodiphenyl sulfide, 4,4'-diaminodiphenyl sulfone, etc. can be used.

The peroxides used in the present invention include versil peroxide, dicumyl peroxide, t-7'' thyl peroxybenzoate, di-t-phthyl peroxide, di-t-butyl peroxydi-isopropylbenzene, etc. It is.

Peroxide can be used within the range of practical moldability, such as molding in about 1 to 5 minutes at a temperature of 150 to 180°C, preferably 0.1 to 100 parts by weight of the component consisting of bisimide and diamine. and 10 weight percent.

If the amount of peroxide is 10 parts by weight or more, the moldability or heat resistance will deteriorate.

As for the method of adding peroxide, it is possible to melt mix it with components such as bisimide, diamine, etc. from the beginning, but it is more preferable to add components such as bisimide, diamine, filler, etc.
Another method is to melt and knead at a temperature below C and add peroxide as soon as sufficient kneading is achieved.

This is to prevent a sudden increase in melt viscosity in order to increase the affinity between bisimide, diamine and filler.

The filler components used in the present invention include thermally stable inorganic or organic substances such as silica powder, alumina powder,
Calcium silicate powder, aluminum hydroxide powder, copper powder,
glass powder, mica powder, asbestos fiber, graphite,
These include glass fiber, carbon fiber, and synthetic fiber.

It is necessary for the purposes of this invention that these filler components be added to the bisimide and diamine monomers.

Pigments such as carbon black in an amount of 0.1 to 5.0 percent by weight, mold release agents or modifiers such as stearic acid, zinc stearate, Montana socks, etc. in an amount of 0.1 to 5.0 percent by weight based on the filler component. may be included.

The molding composition according to the invention can be obtained in several ways.

For example, bisimide, diamine, peroxide, and filler components are heated and kneaded using a roll, co-kneader, Henschel mixer, extruder, or the like.

The composition can then be cooled, solidified and ground for use.

In any of these heat softening and melting methods, the temperature is 150°C.
The mixture is usually cooled as soon as uniform incorporation is achieved to minimize reaction between the bisimide and the diamine.

However, in some cases, as an additional measure to shorten the curing time, mixing may be continued at a temperature lower than 150 DEG C. in order to extend the kneading time or to allow the reaction to proceed to the B-stage.

At temperatures above 150°C, the melt viscosity increases rapidly, making manufacturing operations difficult.

In some cases, a small amount of organic solvent may also be used at the beginning of mixing to enhance the effect of impregnating the filler.

The thermosetting resin composition for molding thus obtained is
The manufacturing process is simplified, and it has excellent moldability such as fluidity and curability, and the molded and cured product using this composition has excellent mechanical properties and heat resistance, making it an innovative thermosetting product for molding. It was a plastic resin composition.

The fluidity of the composition according to the present invention was evaluated by a spiral flow test method.

A spiral flow mold is a spiral mold with a fillet width of 5 mm and a depth of 5 mm. Calculate from the plunger area the distance that the molding composition flows through the gate at a pressure of 230 kq/crA and 150 ± 5 ° C. Ta.

Usually, the materials that can be transfer molded or injection molded are 20~
It is preferable to have a flow of about 150 (m), preferably about 30 to 100 crrL.

Examples will be described below. Example I N-N'-4,4'-,>25 parts of phenylmethane bismaleimide, 10 parts of 4,4'-diaminodiphenylmethane, 37 parts of 6 mm long glass fiber, 25 parts of silica powder, 1 part of carbon black, 1.2 parts of stearic acid at 120℃
The mixture was melt-kneaded for 10 minutes using hot rolls, 0.8 part of dicumyl peroxide was added thereto, and the mixture was further kneaded for 10 minutes at 120'C.

After cooling, the obtained sheet was pulverized using an impact pulverizer.

The spiral flow of this powder composition was 75 cfrL.

This powder composition was transferred to 165°C.
It was molded for 5 minutes and then heat-treated at 200°C for 24 hours.

The bending strength of this molded product conforms to JIS K6911.

The same applies to the following examples) was 15.1 kg/ma.

Furthermore, even after heat treatment at 200℃ for 1000 hours, the bending strength remains 1.
It was 4.2 kg/ma.

Comparative Example I 25 parts of N-N'-4,4'-diphenylmethane bismaleimide and 10 parts of 4,4'-diaminodiphenylmethane were stirred at 160°C for 20 minutes.

The prepolymer with a softening point of 85°C obtained after cooling was pulverized,
Further, 0.8 parts of dicumyl peroxide, 37 parts of 6-length glass fiber, 25 parts of silica powder, 1.2 parts of stearic acid, and 1 part of carbon black were mixed and melted with a hot roll in the same manner as in Example 1. Kneaded.

The spiral flow of this powder composition was 9.5 crrL.

Compared to Example 1, Comparative Example 1 has significantly poorer flow.

After molding this powder composition in the same manner as in Example 1,
The bending strength of the molded product heat-treated at ℃ for 24 hours is 10.3.
kg/wait.

Example 2 30 parts of N-N'-4°4'-diphenylmethane bismaleimide, 5 parts of 4,4'-diaminodiphenylmethane, 25 parts of glass fiber, 35 parts of silica powder, 2 parts of magnesium oxide, 2.6 parts of zinc stearate. 1 part were melt-kneaded for 20 minutes using heated rolls at 100°C, and further 0.4 part of dicumyl peroxide was added and kneaded for 10 minutes.

The spiral flow of the composition obtained by cooling and pulverizing was 5.
It was 3crrL.

This mixture can be molded by transfer molding at a temperature of 160°C in 5 minutes, and the bending strength of the molded product heat-treated at 200°C for 4 hours is 12.8 kg/mt? It was t.

Also, the bending strength at 200℃ is 12.1 kg/ma.
Yes, it has high heat resistance.

Example 3 28 parts of N-N'-4,4' diphenyl ether bismaleimide, 10 parts of 4,4'-diaminodiphenyl ether, 0.2 part of benzoyl peroxide, 0.4 part of dicumyl peroxide, asbestos fiber 30 parts of clay powder, and 1.4 parts of stearic acid were melt-kneaded for 10 minutes using heated rolls at 140°C.

The spiral flow of the obtained powder composition was 63CrfL.
Met.

Compression molded at 180°C for 5 minutes, 250°C
The bending strength of the molded product heat-treated for 2 hours is 13.1 kg.
/i4.

Furthermore, even when heated at 200°C, the weight was 12.5 kg/m4.

Example 4 36 parts of N-N'-4,4'-diphenylmethane bismaleimide, 5 parts of 4,4'-diaminodiphenylmethane, 5 parts of the prepolymer produced according to Comparative Example 1, 0.8 part of dicumyl peroxide, glass 20 parts of fiber, 3 parts of clay powder
2 parts and 1.2 parts of stearic acid were melt-kneaded for 10 minutes using a hot roll at 130°C, and then powdered.

The spiral flow of the obtained powder composition was 49 CrrL.
Met.

The bending strength of the molded product obtained by transfer molding at 160°C for 3 minutes was 14.1 ky/mm.
Met.

Furthermore, even when heated at 200°C, the bending strength is 13.7 kg.
/m4.

Claims (1)

[Claims] 1 General formula (where R1 is hydrogen or an alkyl group of C1 to CIO, R2
is a divalent organic group having at least one aromatic group), a diamine represented by the formula (wherein R is a divalent organic group having at least 2 carbon atoms), a peroxide, and a filler. 1. A method for producing a thermosetting resin composition for molding, which comprises melting and kneading the composition and the composition at a temperature of 150° C. or lower, cooling and solidifying the mixture, and then crushing the mixture. 2 The diamine represented by the general formula is 4,4'-diaminodiphenylmethane, 4,4'-diaminodiphenyl ether, m-
The method for producing a thermosetting resin composition for molding according to claim 1, wherein the thermosetting resin composition is at least one selected from the group consisting of phenylenediamine. 3 The bisimide represented by the general formula is a group consisting of N-1'(-4,4'-diphenylmethane bismaleimide, N-N'-4,4' diphenyl ether bismaleimide, N-Nm-phenylene bismaleimide) At least 1 selected from
A method for producing a thermosetting resin composition for molding according to claim 1 or 2, which is a seed. 4 For 1 mole of diamine represented by the general formula, the amount of bisimide represented by the general formula is small (both 1 mol to 10
A method for producing a thermosetting resin composition for molding according to claim 1, 2 or 3, wherein the thermosetting resin composition comprises molar. 5 Claims 1, 2, 3, or 5 consisting of 50 to 500 weight percent of the filler component based on 100 weight percent of the component consisting of the diamine represented by the general formula and the bisimide represented by the general formula. 5. A method for producing a thermosetting resin composition for molding according to item 4. 6 Claims 1, 2, and 3 consist of 0.1 to 10 weight percent peroxide based on 100 weight percent of the component consisting of the diamine represented by the general formula and the bisimide represented by the general formula. ,
A method for producing a thermosetting resin composition for molding according to item 4 or 5.