JPH01172468A - Modified maleimide resin varnish - Google Patents

Abstract

PURPOSE:To obtain the title varnish excellent in long-term heat resistance, adhesiveness and drillability, by dissolving a specified maleimide resin, an epoxy resin and an aromatic polyamine as essential components in a solvent based on a cyclic ether. CONSTITUTION:The title varnish is produced by dissolving 100pts.wt. maleimide resin (A) containing 40-70wt.% bismaleimide obtained by reacting maleic anhydride with an aromatic diamine (e.g., N,N'-m-phenylenebismaleimide) and 60-30wt.% prepolymer of an MW of 500-5,000, 10-200pts.wt. epoxy resin (B) (e.g., bisphenol A epoxy resin) and 5-50pts.wt. aromatic polyamine (C) (e.g., 4,4-diaminodiphenyl sulfone) as essential components in a solvent based on a cyclic ether (e.g., tetrahydrofuran). A cured product of this varnish is excellent in long-term heat resistance, adhesiveness and drillability, so that it can give very excellent products when used in the production of laminates, multilayer printed boards, etc.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a heat-resistant modified maleimide resin face that has good workability and hardenability, and has excellent adhesiveness, drillability, and long-term heat resistance. be.

[Subject skill]

Conventionally, bismaleimide, polyamino bismaleimide resin, and the like are well known as thermosetting heat-resistant resins.

Bismaleimide has poor solubility and curing properties, and although it has excellent heat resistance when fully cured, it is brittle and has weak adhesive properties, making it impractical for festivals as it is.
Therefore, for -a, a polyamino bismaleimide resin face modified with an aromatic diamine has been put into practical use.

However, polyamino bismaleimide resins are only soluble in high-boiling polar solvents and are slow to cure.

Vostkiair requires a lot of energy →. Moreover, even this polyamino bismaleimide resin has not yet reached a satisfactory level of brittleness and adhesiveness.

The present inventors have already proposed a modified maleimide resin consisting of a maleimide resin, an epoxy resin, and a phenolic resin (Japanese Patent Application No. 182264/1983), but these have poor curability, heat resistance, adhesion, and drill workability. Although this is excellent, there is a growing demand for further improvements in long-term heat resistance, adhesion, and drilling workability.

[Purpose of the invention]

The present invention provides that maleimide resin containing components with an appropriate molecular weight distribution, due to intermolecular condensation, has a low melting point, low solubility,
It was found that the resin has good curability and excellent compatibility with other thermosetting resins, and based on this knowledge, various studies were carried out and the present invention was completed. The purpose is to obtain a modified maleimide resin varnish that has excellent long-term heat resistance, adhesion, and drillability.

[Structure of the invention]

The present invention uses 40 to 70% by weight of bismaleimide obtained from the reaction of maleic anhydride and aromatic diamine and 6% of a prepolymer with a molecular fit of 500 to 5,000.
Maleimide resin (A) containing 0-30ffi amount% 1
00 parts by weight, epoxy resin (B) 10-20
The present invention relates to a modified maleimide resin varnish which contains 0 parts by weight and 5 to 50 parts by weight of aromatic polyamine (C) as essential components and is mainly dissolved in a cyclic ether.

Bismaleimide, which is one of the maleimide resin components of the present invention, is represented by the following formula (11).

(R represents a divalent aromatic group) Specific examples include N, N'-m-phenylene bismaleimide, N, N'-p-phenylene bismaleimide, N,
N'-m-toluylene bismaleimide, N, N'-4,
4'-biphenylene bismaleimide, N, N'-4,4
'-(3,3'-dimedyrubiphenylene)bismaleimide, N,N-4,4'-diphenylmethanebismaleimide, N,N'-4,4'-(3,3'-dimethyldiphenylmethane]bis Maleimide, N, N'-4゜4'-
C3,3'-diethyldiphenylmethane]bismaleimide, N,N'-4,4'-diphenylpropane bismaleimide, N,N'-4,4'-diphenyl ether bismaleimide, N,N'-3,3'- Examples include diphenylsulfone bismaleimide and N,N'-4,4'-diphenylsulfone bismaleimide. There is no problem even if two or more of these are included.

Bismaleimide needs to be contained in the maleimide resin in an amount of 40 to 70% by weight. If it exceeds 70% by weight, the solubility in the solvent decreases, precipitation occurs, and the storage stability of the varnish is extremely deteriorated. In addition, the curing speed is slow. On the other hand, if it is less than 40% by weight, components with a large molecular weight will increase, and some components with a molecular weight of 110,000 or more will also be included, resulting in the formation of insoluble matter and the viscosity of the varnish. Due to the excessive increase in viscosity and the increase in viscosity, disadvantages such as a very short pot life of the varnish occur.

Molecular weight in maleimide resin 500 or more, s, ooo
The following components are preforms that are produced simultaneously with bismaleimide obtained by intramolecular dehydration condensation reaction when excess maleic anhydride and aromatic diamine are reacted in the absence of a solvent at a temperature of 130 to 200°C. It is a polymer obtained mainly by an intermolecular dehydration condensation reaction, and on the high temperature side it also includes a thermal polymer of bismaleimide.

When diluting with a solvent during the reaction, the formation of this prepolymer is drastically reduced.

Components with a molecular weight of 500 or more and 5,000 or less lower the melting point of bismaleimide and promote solubility in solvents, making it soluble not only in expensive high-boiling polar solvents but also in cyclic ethers such as tetrahydrofuran and dioxane. become.

Components with a molecular weight larger than s, ooo reduce the solubility in cyclic ethers, increase the varnish friability at the same resin content weight, increase the setting speed, and shorten the pot life of the varnish. This is not desirable. A component having a molecular weight of less than 500 reduces the solubility of the bismaleimide component in cyclic ethers.

The component having a molecular weight of 500 or more and 5,000 or less is preferably contained in the resin in an amount of 30 to 60%.

If it is less than 30%, there is too much bismaleimide, so the solubility decreases, precipitation occurs, and the shelf life of the varnish deteriorates. On the other hand, if it exceeds 60%, components with molecular weights larger than s, ooo will also be included, resulting in the above-mentioned disadvantages. Here, the molecular weight is measured using a gel permeation chromatograph (G It is a value measured by PC) and converted using a standard polystyrene test line.

There are no particular restrictions on the epoxy resin, but for example, diglycidyl ether of bisphenol A, 4°4'-di(1
,2-epoxyethyl)diphenyl ether, 4.4'
-(1,2-epoxyethyl)diphenyl ether, glycidyl ether of resorcinol, butadiene jepoxide, bis-(2,3-epoxycyclopentyl) ether, 2,2-bis(3,4-epoxycyclohexyl)propane, phloroglucin Difunctional epoxy compounds such as diglycidyl ether of , diglycidyl ether of methylphloroglucin, polyglycidyl ether of phenols-formaldehyde novolak, triglycidyl ether of trimethylolpropane, triglycidyl ether of glycerin, 1,3 .5-tri (1,2
Tri- or higher functional epoxy compounds such as -epoxyethyl)benzene, polyallyl glycidyl ether, and triglycidyl ether of para-aminophenol are used.

These compounds can be used alone or in combination depending on the use and purpose. The amount of epoxy resin added is 10 to 200 parts per 1001 parts of maleimide resin.
Parts by weight are preferred.

If the amount of epoxy resin is less than 10 parts by weight, improvements in adhesion and drill workability will not be sufficient, and if it exceeds 200 parts by weight, heat resistance such as glass transition temperature will decrease.

Examples of aromatic polyamines include m- or p-phinylene diamine, 4,4'-diaminodiphenylmethane, 3,3'-dimethyl-4,4-diaminodiphenylmethane, 3,3'-diethyl-4, 4゛-diaminodiphenylmethane, 2゜2-bis(4-aminophenyl)propane, 4゜4'-diaminodiphenyl ether, 4.
4'-diaminodiphenylsulfone, m- or p-xylylenediamine, and also has an average composition of the general formula (however,
n>Q, R is CH, or C* Hs −, atmi(
i is a number indicating the order of benzene nuclei in []), 'm' and m' are 0.1 or 2. ) can be mentioned.

By including an aromatic amine as a varnish component, it is possible to provide a kind of flexibility and stability to the bonds between molecules compared to modified maleimide resin varnishes made of phenolic resin, maleimide resin, and epoxy resin. Ta.

The amount of aromatic polyamine added is 100% of maleimide resin!
If the aromatic polyamine is less than 5 parts by weight, adhesion, drilling workability, and long-term heat resistance will not be sufficiently improved like epoxy resins.
Dimensional stability is also poor, and if it exceeds 50 parts by weight, heat resistance such as glass transition temperature decreases.

As the solvent used in the present invention, high-boiling polar solvents such as dimethylformamide, dimethylacetamide, and N-methylpyrrolidone can be used, but low-boiling cyclic ethers with good workability and the ability to remove the solvent at low temperatures and in a short time are preferable. More preferred.

Examples of the cyclic ethers include tetrahydrofuran, 2-methyltetrahydrofuran, 3-methyltetrahydrofuran, 2,5-dimethyltetrahydrofuran, 2-ethyltetrahydrofuran, 1,4-dioxane, and 1,3-dioxane. Further, a mixed solvent may be used in which these are the main solvents and other general organic solvents are added as long as the solubility is not deteriorated.

When making a varnish, the maleimide resin 10 mentioned above is used.
0 parts by weight of epoxy resin 1O~200 (more preferably 50~100) ff! ffi part, aromatic polyamine 5 to 50 (preferably 10 to 30 parts by weight) are blended at once so that the resin content of the face is 60% by weight, or each component is blended so that the resin content of the varnish is 60% by weight. Prepare each by dissolving them in a solvent and remixing them in the above proportions.

If necessary, a curing catalyst such as tertiary amines, imidazoles, phosphines, or organic peroxides may be added to the modified maleimide resin varnish.

〔Effect of the invention〕

The cured product made from the modified maleimide resin varnish of the present invention has excellent long-term heat resistance, as well as excellent adhesion and drilling workability, so it is extremely suitable for use in the production of laminates, multilayer printed boards, etc. is obtained.

In addition, the maleimide resin used in the present invention can be used as it is by reacting maleic anhydride with an aromatic diamine, and the solvent used can be one with a low boiling point. The solvent can be removed quickly, which is advantageous in terms of workability.

Further, a curing catalyst may be added if necessary, so that a product with good curability can be obtained and can be sufficiently cured at a lower temperature than polyamino bismaleimide.

〔Example〕

[Synthesis example of maleimide resin] Synthesis examples 1 to 5 According to the formulation in Table 1, maleic anhydride was melted, and an aromatic diamine was gradually added thereto.
A dehydration reaction was carried out under a reduced pressure of 0 m51 g under the conditions shown in Table 1. Next, 20 g of xylene and 200 g of hot water were added and mixed with stirring for 5 minutes while refluxing. When left to stand still, the extracted water separates into an upper layer. This was removed by suction, 200 g of hot water was added twice, and the same washing was repeated twice.

Thereafter, residual moisture and xylene were distilled off under reduced pressure to obtain a maleimide resin.

[Examples 1 to 5] The resin compositions obtained in Synthesis Examples 1 to 4 were treated with a solvent according to the formulations in Table 2 so that the viscosity of the mixture was 1.0±0.5 poise (25°C). Prepared. A surface-treated glass cloth was impregnated with this and heated in a dryer at 110° C. for 5 minutes to remove the solvent, thereby producing a prepreg. The volatile matter was 0.5% or less, and almost no solvent remained.

Eight sheets of the above prepreg were stacked and heated and pressed to obtain a laminate.

[Comparative Examples 1 to 7] Using N-methylpyrrolidone as a solvent, the resin composition obtained in Synthesis Example 5, N,N'-4,4'-diphenylmethane bismaleimide and polyamino bismaleimide were mixed as shown in Table 2. According to the formulation viscosity is 1.0±0.5 poise (2
5°C) using a solvent. However, comparative example 2
A large amount of insoluble matter remained and it was not possible to make it into a varnish.

In Comparative Example 1 and Comparative Examples 3 to 5, surface-treated glass cloth was impregnated and heated in a dryer to remove the solvent, thereby creating BUJ preg. The volatile content is higher than in Examples 1-5.

Furthermore, eight sheets of each prepreg were stacked and heated and pressed to obtain an 82-layer board.

Comparative Examples 6.7 are those in which the aromatic polyamine was replaced with a phenolic resin. Long-term heat resistance and peel strength are slightly inferior to Examples.

DSC was measured on formulations without added solvent.

It can be seen that Examples 1 to 5 have exothermic peak temperatures 20°C or more lower than Comparative Examples 1 to 5, and have good curability.

The laminate had good delamination strength, dimensional stability, and drillability, and a high glass transition temperature was obtained without post-curing.

Table 1 DDM; 4,4'-diaminodiphenylmethane Dr)E
;4,4'-diaminodiphenyl ether 8A;
3.3'-diethyl J-ray 4.4'-diaminodiphenylmethane *Im Solubility: 1.4 dioxane 50% solution *2 Stability: Viscosity of soluble material *2 Storage stability: Leave at room temperature for 7 days or more ○ No abnormality ml
Kelimide (manufactured by Rhone-Poulenc) *2 Epoxy W1190, bisphenol A type epoxy resin *3 Novolac type epoxy resin *44.4-Diaminodiphenylsulfone *5 Made by Sumitomo Delerez PR-51470 *6 No voids or fading 01 Molding Poor properties× *7 Dimensional change rate after 7 days treatment at 230°C (average value in X and Y directions) *8 No smear, peeling, etc. occur during drilling○

Claims (1)

[Claims] 40 to 70% by weight of bismaleimide obtained from the reaction of maleic anhydride and aromatic diamine and a molecular weight of 50%.
10 to 200 parts by weight of an epoxy resin (B) and 5 to 50 parts by weight of an aromatic polyamine (C) per 100 parts by weight of a maleimide resin (A) containing 60 to 30% by weight of a prepolymer having a molecular weight of 0 to 5,000. 1. A modified maleimide resin varnish characterized by having 10% as an essential component and mainly dissolved in a cyclic ether.