JPS6392624A - Production of thermosetting resin composition - Google Patents

Abstract

PURPOSE:To obtain the title easily moldable composition which can give a three-dimensional cured product of a low dielectric constant and excellent heat resistance, by prereacting 1,5,9-cyclododecatriene with a specified polymaleimide in an inert solvent. CONSTITUTION:10-30wt% 1,5,9-cyclododecatriene (A) which is a nonconjugated cyclotriene obtained by cyclopolymerizing three 1,3-butadiene molecules is prereacted with 90-70wt% polymaleimide (B) of the formula (wherein R1 is an n-valent 2C or higher organic group and a is 2-10), e.g., N,N'-p,p'- diphenylmethanebismaleimide, at 100-200 deg.C in an inert solvent (C) (e.g., cyclohexane) in an amount to give a resin content <=70wt% to the obtained varnish to obtain the title composition which is a varnish which, even when cooled to room temperature, does not cause phase separation and can be kept in a uniform state. If necessary, an organic peroxide as a radical reaction initiator may be added to this composition.

Description

Detailed Description of the Invention [Field of Industrial Application] The present invention relates to a method for producing a thermosetting resin composition used for producing various molded products, laminates, etc. The present invention relates to a method for producing a thermosetting resin composition with high heat resistance.

[Conventional technology]

Conventionally, as an organic polymer material with a low dielectric constant and high heat resistance, polytetrafluoroethylene or 1,2-polybutadiene, which is disclosed in Japanese Patent Publication No. 59-5207 and Japanese Patent Publication No. 60-11634, has been used. Mixtures with maleimide compounds are used.

[Problem that the invention seeks to solve]

However, polytetrafluoroethylene has a melting point of 320° C., which requires the molding temperature to be higher than the melting point, making it difficult to mold.

In addition, the mixture of 1,2-polybutadiene and maleimide compound is a non-polar polymer, whereas the latter is a non-polar polymer.
Since they are polar compounds, there is no suitable common solvent for making them into solutions, and only solutions with very low concentrations can be obtained. That is, for example, a solution of epoxy resin or polyimide resin for laminates can have a resin content of about 50% by weight, whereas a mixture of 1,2-polybutadiene and a maleimide compound has a resin content of at most 30% by weight. Only a solution with a certain concentration can be obtained.

The present invention was made in view of the above circumstances, and is a thermosetting resin composition that can obtain a highly concentrated homogeneous solution, is easy to mold, has a low dielectric constant of a three-dimensionally cured cured product, and has high heat resistance. The aim is to provide methods for manufacturing products.

[Means for solving problems]

As a result of intensive studies to solve the above problems, the present inventors have found that the above object can be achieved by pre-reacting 1,5,9-cyclododecatriene and a specific polymaleimide in an inert solvent. The present invention was completed based on the discovery that the method for producing the thermosetting resin composition of the present invention is based on 1,5,9-cyclododecatriene and the general formula (where R is at least two carbon atoms). (represents an a-valent organic group having an atom, a represents a number of 2 or more and 10 or less.) It is characterized by preliminarily reacting with a polymaleimide represented by the following in an inert solvent.

1,5,9-cyclododecatriene used in the method of the present invention is a non-conjugated cyclic triene, and is synthesized, for example, by cyclopolymerizing three molecules of 1,3-butadiene.

1.5.9-Cyclododecatriene is currently known to have two isomers: cis-trans-trans and trans-trans-trans. Either type can be used, and a mixture of these can be used. May be used.

Furthermore, the polymaleimide (1
) as N,N'-ethylene bismaleimide, N,
N'-m-phenylene bismaleimide, N, N'-p-
Phenylene bismaleimide, N, N'-hexamethylene bismaleimide, NIN'-p, p'-diphenyldimethylsilyl bismaleimide, N, N'-p, p'-diphenylmethane bismaleimide, N, N'-p, p '-diphenyl ether bismaleimide, N, N'-p.

p'-diphenylsulfone bismaleimide N.

N'-dicyclohexylmethane bismaleimide, N, N
'-m-xylene bismaleimide, N, N'-(3,
3'-dichloro-p,p'-bisphenylene)bismaleimide, N,N'-(3,3'-diphenyloxy)bismaleimide, 3.3'.

4.4'-diphenylmethane bismaleimide and the general formula (in which R2 represents an organic group having from 1 to 8 carbon atoms, and b represents a number with an average value ranging from 0.1 to 8.0). ), preferably N, N
'-p, p', diphenylmethane bismaleimide and a polymaleimide of formula II (R2 is CH2M).

Inert solvents that can be used in the method of the present invention include methyl ethyl ketone, methyl propyl ketone, methyl isopropyl ketone, methyl butyl ketone, methyl isobutyl ketone, binacolon, diethyl ketone, butylon, diisopropyl ketone, cyclobutanone, cyclopentanone, cyclohexanone, alkylene glycol. Monoalkyl ethers, N,N-dimethylformamide, tetrahydrofuran, 1,4-dioxane, diglyme, toluene, xylene, trichloroethylene, etc. can be used.
When the polymaleimide is N,N'-p,p'-diphenylmethane bismaleimide, cyclohexanone or N
, N-dimethylformamide is preferably used.

The present inventors have found that by pre-reacting 1.5°9-cyclododecatriene and the above-mentioned polymaleimide in these inert solvents by heating, a uniform varnish can be obtained. It was also found that a homogeneous state was maintained without causing two-layer separation.

The preliminary reaction temperature is not particularly limited, but is 100°C to 2°C.
The range is preferably 00°C, particularly preferably 1
It is in the range of 50°C to 170°C.

If the preliminary reaction temperature is lower than 100°C, the reaction will take a long time, and if it is higher than 200°C, the polymaleimides will react with each other, resulting in gelation.

The time required for the preliminary reaction varies depending on the type of solvent used and the type of polymaleimide, and when the varnish is returned to room temperature,
This can be continued until a uniform condition is maintained. If the pre-reaction time is too short, the varnish will separate into two layers, and if the pre-reaction time is too long, gelation will occur.

The ratio of 1,5.9-cyclododecatriene to the total amount of 1.5.9-cyclododecatriene and polymaleimide is not particularly limited, but is preferably 10% by weight to 30% by weight.

1.5.9-Cyclododecatriene proportion is 10% by weight
If the amount is less, the effect of lowering the dielectric constant will not be noticeable, and if it is more than 30% by weight, the resin composition will separate into two layers after solvent drying.

The amount of inert solvent to be used is preferably such that the resin content in the varnish after preliminary reaction is 70% by weight or less, and if the concentration exceeds 70% by weight, two-layer separation is likely to occur.

Moreover, the inert solvent used can be removed from the obtained varnish by reducing pressure or heating after the preliminary reaction, thereby making it possible to obtain a homogeneous solution of the desired high concentration thermosetting resin composition.

Furthermore, the curing time can be shortened by adding an appropriate organic peroxide as a radical reaction initiator to the thermosetting resin composition of the present invention, if necessary. Organic peroxides suitable for the method of the present invention include, for example, benzoyl peroxide, dicumyl peroxide, methyl ethyl ketone peroxide, t-butyl perbenzoate, t-butyl peroxylaurate, di-1-
Examples include butyl peroxyphthalate, lauroyl peroxide, and dibenzyl peroxide.

In addition, the thermosetting resin composition of the method of the present invention includes silica,
It is also possible to add commonly used additives such as glass powder, fillers such as aluminum hydroxide, and flame retardants such as tricresyl phosphate, chlorinated paraffin, antimony oxide, monoammonium phosphate, etc.

This thermosetting resin composition is three-dimensionally cured by heating and pressure molding. The heating temperature ranges from 150°C to 300°C, preferably from 180°C to 250°C.

The pressure is 5 kgf/c to make the composition flow to some extent.
i or more is required.

Further, after impregnating a base material with the thermosetting resin composition obtained according to the present invention, the solvent is dried and removed by heating to obtain a prepreg, and after cutting this prepreg to a predetermined size, a predetermined number of sheets are laminated and heated and pressed. A laminate can be produced by curing.

Furthermore, if necessary, a copper-clad laminate can be manufactured by adhering copper foil to both or one side of the prepreg and laminating the prepreg.

As the base material, glass cloth, glass paper, glass nonwoven fabric, gas mat, paper, asbestos paper, aromatic polyamide fiber cloth, quartz fiber cloth, carbon fiber, etc. can be used.

[Effect]

By the method of the present invention, a highly concentrated 1,5,9-cyclododecatriene-polymaleimide composition can be prepared with uniform R? It is thought that the reason why fl is obtained is that 1,5.9-cyclododecatriene and polymaleimide react with each other, resulting in improved solubility in the solvent.

It is also believed that 1,5.9-cyclododecatriene acted to lower the dielectric constant, and polyamide acted to improve heat resistance.

〔Example〕

Hereinafter, the present invention will be explained in more detail with reference to Examples.
The scope of the present invention is not limited in any way by these examples.

Example I 41 parts by weight of N,N'-p,p'-diphenylmethane bismaleimide was dissolved in 50 parts by weight of cyclohexanone at a temperature of 155°C to obtain a solution (A) having a concentration of 45% by weight.

1.5.9-cyclododecatriene, CD in solution (A)
T (1,5.9- with a molecular weight of 162.27 and a cis-trans-trans isomer content of 95% by weight or more)
9 parts by weight of cyclododecatriene (liquid at room temperature, trade name manufactured by Shell Chemical Co., Ltd.) (the ratio of CDT to the total amount of CDT and polymerimide is 8% by weight) so that the concentration of polymaleimide and CDT in the solution is 50% by weight. After mixing as described above, the solution (B
) was obtained. Solution CB) remained homogeneous without turbidity even after cooling to room temperature.

Comparative Example 1 Solution (C) was prepared in the same manner as in Example 1, except that the preliminary reaction was not performed and the reaction time of N,N'-p,p'-diphenylmethane bismaleimide and CDT was changed to 30 minutes. .

After the solution (C) was cooled to room temperature, it separated into two layers.

Example 2 49 parts by weight of N,N'-p,p'-diphenylmethane bismaleimide was mixed with N at a temperature of 155°C.

It was dissolved in 40 parts by weight of N-dimethylformamide to obtain a solution CD) with a concentration of 55% by weight.

711 parts by weight of the above-mentioned CD (the ratio of CDT to the total amount of CDT and polymaleimide is 18% by weight)
were mixed so that the concentration of polymaleimide and CDT in the solution was 60% by weight, and then heated at 120% at a temperature of 155°C.
The mixture was reacted for a minute to obtain a solution (E). Solution (E) remained homogeneous without turbidity even after cooling to room temperature.

Add glass cloth G-7010-BX (aminosilane treated 0.11-thickness glass cloth, manufactured by Nittobo) to solution [E].
was immersed and dried by heating at 170°C for 2 minutes to remove the solvent, yielding a prepreg with a resin content of 60% by weight. Twelve sheets of this prepreg are stacked, and electrolytic copper foil NDGAC-
35 (35, cam single-sided roughened copper foil, manufactured by Nippon Denki Co., Ltd.) was stacked, and the pressure was 80 kgf/co! A copper-clad laminate having a thickness of 1.6 fl was produced by press molding at a temperature of 200° C. and a molding time of 2 hours.

The obtained copper-clad laminate had a low dielectric constant and excellent heat resistance when its dielectric constant, dielectric loss tangent, glass transition temperature, and copper foil peeling strength were measured.

The measurement results are shown in Table 1.

Comparative Example 2 22 parts by weight of the above CDT (
The ratio of CDT to the total amount of CDT and polymaleimide is 31% by weight). After mixing with DMF so that the concentration of polymaleimide and CDT in the solution is 60% by weight, the solution is reacted at a temperature of 155°C for 120 minutes. CF) was obtained. A prepreg was prepared by removing the solvent using solution (F) in the same manner as in Example 2, but the liquid CDT was separated from the resin composition and formed into two layers.

Comparative Example 3 Polyimide resin copper clad laminate MCL-1-67 (1.6 m
The dielectric constant, dielectric loss tangent, glass transition temperature, and copper foil peeling strength were measured using a film with a thickness of 1.5 m (trade name, manufactured by Hitachi Chemical Co., Ltd.). The measurement results are shown in Table 1.

Margin below Table 1 ') Measured according to JI 5-C-6481.

2' Measured using thermomechanical testing machine TMA.

Temperature increase rate: 5°C/mxn, load: 5g [Effects of the Invention] As described above in detail, according to the present invention, 1.5
．． A highly concentrated homogeneous solution of 9-cyclododecatriene and polymaleimide can be obtained, and a thermosetting resin composition can be obtained that is easy to mold, has a low dielectric constant of the three-dimensionally cured cured product (and has high heat resistance). , its industrial value is great.

Claims (1)

[Claims] 1,1,5,9-cyclododecatriene and the general formula ▲ Numerical formulas, chemical formulas, tables, etc. ▼ [I] (Here, R_1 is a having at least 2 carbon atoms
represents a valent organic group, and a represents a number of 2 or more and 10 or less. ) A method for producing a thermosetting resin composition, which comprises preliminarily reacting a polymaleimide represented by the following formula in an inert solvent. 2. The method for producing a thermosetting resin composition according to claim 1, wherein the polymaleimide is N,N'-p,p'-diphenylmethane bismaleimide.