JPS6343420B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a thermosetting resin composition having excellent heat resistance.

Polyimide resins have excellent heat resistance, chemical resistance, etc., and have traditionally been used in various applications such as films used at high temperatures, electric wire coatings, laminates, paints, adhesives, and molded products.

Among them, homopolymers of maleimide compounds are
Although it has excellent thermal properties, as is clear from its molecular structure, it does not have sufficient mechanical strength, so by copolymerizing it with other materials,
It is used by sacrificing some of its thermal properties and improving its mechanical strength.

On the other hand, the product name TRADLON is available in the United States.
Polyparabanic acid sold by EXXON has excellent mechanical and thermal properties, but it is difficult to process and requires high temperatures and pressures to make molded products and laminated products, so it is currently widely used. The problem was that the existing processing equipment for phenolic resins, epoxy resins, etc. could not be used as is.

The present invention was made to solve these difficulties, and provides a thermosetting resin composition that has good heat resistance and mechanical properties, has excellent processability, and can be widely used for lamination or as a molding material. It is something.

That is, the present invention provides (A)(a) a dimaleimide compound,
or (B) a maleimide compound consisting of a mixture of (a) a dimaleimide compound and (b) a monomaleimide compound;
Polyparabanic acid and (C) imidazole compound,
Component (A) is 15 to 85% by weight based on the total amount of component (B)
Therefore, component (B) is 85 to 85% of the total amount of component (A).
It relates to a thermosetting resin composition in which component (C) and component (A) are mixed in an amount of 0.5 to 5% by weight based on the total amount of component (A).

In the present invention, the maleimide compound (A) constituting a component of the thermosetting resin composition includes 4,4'-methylenebis(N-phenylmaleimide), 4,4'-
Oxikibis (N-phenylmaleimide, N.
It is preferable to use bismaleimides represented by the general formula () such as N'-sulfone bis(N-phenylmaleimide) and N.N'-dithiobis(N-phenylmaleimide). (In the formula, R ₅ represents a hydrogen atom or an alkyl group, and R ₆ represents a divalent organic group. The same applies hereinafter.) A part of it is N-phenylmaleimide, N-3
It is also possible to replace it with a monomaleimide represented by the general formula () such as -chlorophenylmaleimide and N-4-nitroenylmaleimide.

(R ₇ represents a monovalent organic group.) In this case, the amount of monomaleimide in the total amount of maleimide compound is preferably 20% by weight or less.

These maleimide compounds contain 15
Use in the range of ~85% by weight.

If the blending ratio of the maleimide compound is less than 15% by weight, the desired processability cannot be obtained, while if it exceeds 85% by weight, the workability improves, but the mechanical strength decreases. , it becomes difficult to obtain a heat-resistant molding material with good properties.

In the present invention, as the polyparabanic acid (B) which constitutes another component of the composition, there is TRADLON, which is sold by EXXON of the United States in the form of a dimethylformamide solution, and this is added to the solid content of the mixture with the maleimide compound. It is used in a range of 85 to 15% by weight based on the total weight.

If the amount of polyparabanic acid is less than 15% by weight,
If the mechanical strength is not improved and the content exceeds 85% by weight, processability will decrease, and in either case, it will be difficult to obtain desirable properties as a heat-resistant molding material.

Furthermore, the imidazole compound (C), which is another component in the present invention, plays a role as a curing accelerator for the maleimide compound (A), and is present in an amount of 0.5 to 5% by weight based on the solid content of the maleimide compound. Add amount.

If the amount of the imidazole compound (C) added is less than 0.5% by weight, the effect of the addition will not be apparent, whereas if it exceeds 5% by weight, curing will be too rapid and workability and processability will deteriorate.

In carrying out the present invention, a composition consisting of the above components, that is, a composition consisting of a mixture of a maleimide compound, a dimethylformamide solution of polyparabanic acid, and an imidazole compound, is usually mixed with N-methyl-2- It is used by dissolving it in an organic solvent such as pyrrolidone, dimethylformamide, or dimethylacetamide.

After immersing a forming base material such as glass cloth or cotton cloth in this resin solution, or applying the resin solution to these base materials, several sheets of prepreg obtained by volatilizing and removing the solvent are stacked together and heated and pressed. By molding, a laminate product with excellent heat resistance and electrical properties can be obtained.

Furthermore, by pouring this resin solution into a large excess of water while stirring, and separating and drying only the precipitated resin, a thermosetting resin powder that can be molded at 180 to 200°C can be obtained. A molded article with excellent thermal and mechanical properties can be obtained by a method such as molding this resin powder in a metal mold.

In the thermosetting resin composition of the present invention, the components (A), (B), and (C) described above do not substantially react with each other. That is, the components (A) and (B) simply exist as a mixture in a polymer state. In addition, component (C) is a component that polarizes component (A) and accelerates curing due to the solvent effect, and is similar to component (A).
There is no direct reaction with component (C). Therefore, the thermosetting resin composition of the present invention in which components (A), (B), and (C) are mixed can be thermally polymerized by heating. A mixed composition is obtained.

As described above, the composition of the present invention has excellent properties such as good heat resistance, processability, and mechanical properties, since the maleimide resin and polyparabanic acid compensate for each other's shortcomings, so it can be used for various industrial purposes. It can be used for

Examples of the present invention will be described below, but the present invention is not limited thereto.

Example 1 60 g of N・N′-methylenebis(N-phenylmaleimide) and 300 g of a 20% by weight solution of polyparabanic acid in dimethylformamide were mixed, heated to 100°C, and 2MZ-agine (Shikoku Kasei Co., Ltd.) was added to the mixture. 0.3 g of imidazole compound (trade name) was added to make a homogeneous solution, and 40 g of 1,4-dioxane was further added to dilute it to make a 30% by weight resin solution.

The resulting resin solution was applied to a satin type glass cloth treated with γ-aminopropyltriethoxysilane and dried at 150°C for 3 minutes and then at 70°C for 5 minutes to obtain a prepreg. Next, sheets of this prepreg are stacked together and preformed in a press heated to 200°C, degassing twice, and then heated to 70°C.
A pressure of Kg/cm ² was applied for 60 minutes to obtain a laminate.

This laminate was kept at a temperature of 220°C for 15 hours, and after the resin was completely cured, its bending strength was measured.

The measurement results are shown below.

Bending strength: 58Kg/cm ² (room temperature) 38Kg/cm ² (250℃) After heating this laminate at a temperature of 250℃ for 30 days, the bending strength was measured in the same manner, but it was 50Kg/cm ²
(room temperature), almost no decrease in strength was observed.

Example 2 60 g of N・N′-methylenebis(N-phenylmaleimide) and 100 g of a 20% by weight solution of polyparabanic acid in dimethylformamide were mixed, heated to 100°C, and 1.2 g of 2MZ-agine was added thereto. moreover
100 g of dimethylformamide was added to obtain a homogeneous resin solution.

Next, pour this into a large amount of water while stirring, separate the powdery precipitate that has formed, and heat it at 100℃ for 5 minutes.
After drying for several hours, a powdered resin was obtained.

Put this into a mold heated to 200℃ and make 120Kg/cm ²
When molded at a pressure of 3 minutes, it maintained sufficient hardness to be removed from the mold after 3 minutes of pressure molding.

Next, the obtained molded product was post-cured at a temperature of 250°C, and then its bending strength was measured.

The measurement results are shown below.

Bending strength 12.5Kg/cm ² (room temperature) 11Kg/cm ² (250℃) The bending strength was measured after heating this molded product at a temperature ^of 250℃ for 20 days. ) and maintained sufficient strength.

Furthermore, this molded product and a molded product that was similarly heat- and pressure-molded from the resin solution obtained in Example 1 were gradually heated to a high temperature, and the weight residual ratios at various temperatures were measured. A thermal decomposition curve was obtained.

The results are shown in the graph of the drawing.

[Brief explanation of the drawing]

The drawing is a thermal decomposition curve diagram of a resin molded article obtained from an example of the present invention.

Claims (1)

[Scope of Claims] 1 (A) A maleimide compound consisting of (a) a dimaleimide compound or a mixture of (a) a dimaleimide compound and (b) a monomaleimide compound; (B) a polyparabanic acid represented by the general formula (); , (In the formula, n is a positive integer.) (C) An imidazole compound represented by the general formula (), (In the formula, R ₁ to _{R 4} represent a hydrogen atom or an alkyl group, and may be the same or different from each other.) Component (A) is 15 to 85% by weight based on the total amount of component (B). Therefore, component (B) is 85% of the total amount of component (A).
15% by weight, and a thermosetting resin composition in which component (C) is mixed in an amount of 0.5 to 5% by weight based on the total amount of component (A). 2. The thermosetting resin composition according to claim 1, wherein the monomaleimide compound (A) and (b) is 20% by weight or less based on the total amount of the maleimide compound.