JPH0470329B2 - - Google Patents

Description

[Detailed description of the invention]

[Industrial Field of Application] This invention relates to a curable resin composition used for laminated plates and the like. [Prior art] Generally, resins used for laminates, etc.
Epoxy resins and imide resins are often used. In the case of such laminates, the criteria for resin selection has been to use imide resins and epoxy resins depending on whether the number of laminated layers is 10 or more or less. However, in recent years, the uses of laminates have diversified.
Such a system of use based on the number of laminated layers is no longer sufficient. For example, epoxy resins are required to be further improved in terms of high purity, fast curing, smearing properties, UV blocking properties, etc., while imide resins are required to have a high glass transition point Tg, high flame retardancy, The pursuit of low-temperature curability, low cost, etc. has begun. Particularly recently, there has been a demand for products with performance that lies between those of imide resins and epoxy resins, and in response to this demand, epoxy-modified imide resin prepolymers have been developed in which imide resin prepolymers are modified with epoxy resins. . [Problem to be solved by the invention] However, in the currently used epoxy-modified imide resin prepolymers, the amount of epoxy resin blended is usually increased in order to increase the interlayer adhesion (adhesion) when used in laminates. However, there is a problem in that the glass transition point of the resin after curing becomes low. Therefore, with the aim of creating a curable resin composition that has a high glass transition point and also provides sufficient interlayer adhesion when used in laminates, the inventors wondered how to improve the epoxy resin composition. A study was conducted from the viewpoint of whether it was possible to increase the interlayer adhesion strength without increasing the blending amount. As a result, instead of increasing the amount of epoxy resin blended, we developed an aromatic compound that has multiple imide groups in the main chain, which is the main skeleton of the imide resin prepolymer, and multiple amino groups that react with the epoxy resin. I discovered that I could use what I had. However, it has further been found that simply reacting such a compound with an epoxy resin leaves a large number of unreacted amino groups, which adversely affects heat resistance. Therefore, the inventors first developed the following curable resin composition in order to solve the above problem (Japanese Patent Application No. 148532/1984, etc.). The curable resin composition is made by reacting an aromatic compound having a plurality of imide groups and a plurality of amino groups in the molecule with an epoxy resin, and at least an unsaturated imide compound is blended as a curing agent. Here, the aromatic compounds mentioned above are not particularly limited, but include compounds () and () represented by the following general formula. [In the formula, Ar ¹ represents a divalent aromatic group, Ar ² represents a tetravalent aromatic group, Ar ³ represents a trivalent aromatic group, and p and q are 0 or a positive integer (however, p+q
>0). ] [In the formula, Ar ⁴ is a tetravalent aromatic group that is the same as or different from Ar ² , R ¹ and R ² represent a hydrogen atom, a halogen atom, or an alkyl group, and at least one of R ¹ and R ² is Always an alkyl group. Moreover, m represents a positive integer. ] It is recommended to use at least one of the following. The curable resin composition according to the above invention certainly has a high glass transition point, and when used in a laminate, it can provide sufficient interlayer adhesion and also has good heat resistance. Although the objective has been achieved, further improvements were required, particularly in terms of improving interlayer adhesion. In view of the above circumstances, the present invention aims to develop a curable resin that has a high glass transition point, good heat resistance, and can provide even better interlayer adhesive strength when used as an impregnating resin for laminates. An object of the present invention is to provide a composition. [Means for Solving the Problems] In order to solve the above problems, the resin composition according to the present invention comprises an aromatic compound represented by the following general formula (), or an aromatic compound represented by this and the above general formula (). It is made by reacting an epoxy resin with an unsaturated imide compound as a curing agent. A curing agent other than the above-mentioned unsaturated imide compound may be used in combination, and for example, it is preferable to use a Lewis acid compound in combination. In addition, the above-mentioned epoxy resin contains a brominated epoxy resin, and the amount thereof is 6% by weight in terms of the bromine atom content in the total solid content of the curable resin composition.
It is preferable that it is above. [Function] In this invention, instead of the conventional imide resin prepolymer, an aromatic compound having a plurality of each of imide groups and amino groups in the molecule (hereinafter abbreviated as "imide group-amino group-containing compound") is used. () is used, and an epoxy resin that reacts with the unterminated amino group of the compound () to modify it, and an unsaturated imide compound as a curing agent for the epoxy resin are blended. As a result, the terminal amino group in () above and the epoxy resin react sufficiently, without increasing the content of the epoxy resin (that is, without lowering the glass transition point of the curable resin composition).
Interlayer adhesion can be further improved, and in addition, good heat resistance can also be obtained. [Example] First, the imide group-amino group-containing compound (
(See Publication No. 29584). Ar ₁ and Ar ₂ in the same compound () are each independently a mononuclear or polynuclear divalent aromatic group (residue), and the aromatic ring contains a lower alkyl group, halogen, lower alkoxyl group, etc. A substituent such as a group or a carboxyl group may be included. More specifically, Ar ₁ and Ar ₂ are both residues of aromatic diamines. Examples of aromatic diamines include 4,
4'-diaminodiphenylmethane, 3,3'-diaminodiphenylmethane, 4,4'-diaminodiphenylpropane, 4,4'-diaminodiphenyl, 4,
4'-diaminostilbene, 4,4'-diaminodiphenyl ether, 3,4'-diaminodiphenyl ether, 4,4'-diaminodiphenyl sulfone,
3,3'-diaminodiphenylsulfone, 4,4'-
Diaminodiphenyl sulfide, 3,3'-diaminobenzophenone, 2,4-toluenediamine,
2,6-toluenediamine, m-phenylenediamine, p-phenylenediamine, benzidine, m
-xylylenediamine, p-xylylenediamine, 1,3-bis(3-aminophenoxy)benzene, 1,4-bis(4-aminophenoxy)benzene, 2,2-bis(4-aminophenoxyphenyl)propane , 4,4'-bis(4-aminophenoxy)diphenylsulfone, 4,4'-bis(3-aminophenoxy)diphenylsulfone,
and methyl-, ethyl-, chloro-, methoxy-, ethoxy-, carboxy-, etc. substituents of these listed compounds (e.g., 3,3'-dimethyl-4,4'-diaminophenylmethane, 3,3 ′−
Dimethyl-4,4'-diaminofubienyl, 3,
3'-Dichloro-4,4'-diaminodiphenidylpropane, 3,3'-dichloro-4,4'-diaminodiphenylsulfone, tetrachlorodiaminodiphenylmethane, 3,3'-dimethoxy-4,4 '-diaminobiphenyl, 3,3'-dicarboxy-4,
4'-diaminodiphenylmethane, etc.). In addition, examples of condensed polycyclic (polynuclear) aromatic groups other than benzene rings (mononuclear) include fluorene, anthracene, indane, etc., and aromatic diamines containing these [for example, 9,9-bis(4-
aminophenyl)fluorene, 8,9-bis(4
-aminophenyl)anthracene, 5-amino-
1-(4'-aminophenyl)-1,3,3-trimethylindane, etc.] can also be used in the same manner. The above aromatic diamines may be used alone or in combination; for example, Ar ₁ and Ar ₂ may be equal or different, and Ar ₁ and/or Ar ₂ may each be used as Multiple types may be used. R ₁ , R ₂ and n are as described above. The above-mentioned imide group-amino group-containing compound () is, for example, the above-mentioned aromatic diamine and an acid anhydride () represented by the following general formula. [In the formula, R ₁ and R ₂ are the same as above. ] can be synthesized by a conventional imidization reaction. Further, as a commercially available product, the product name TSM-20 (manufactured by Sumitomo Chemical Co., Ltd.) or the like may be used. In the curable resin composition according to the present invention, in addition to the above-mentioned imide-based amino group-containing compound (), the above-mentioned imide-based amino group-containing compound () is used.
(Japanese Patent Application No. 62-148532, etc.) can also be used in combination. The imido group-amino group-containing compound (2) can be obtained by reacting an aromatic tetracarboxylic acid or its derivative with a molar excess of an aromatic diamine component in a suitable solvent. Examples of the aromatic tetracarboxylic acids include pyromellitic acid,
3,3',4,4'-benzophenonetetracarboxylic acid, 3,3',4,4'-diphenyl ether tetracarboxylic acid, 3,3',4,4'-biphenyltetracarboxylic acid, 2,3,6,7-naphthalenetetracarboxylic acid, 2,2-bis(3,4-dicarboxyphenyl)propane, etc. are used as aromatic diamine components, o-alkyl substituted aniline-formaldehyde condensate (alkyl Examples of the _solvent include amide solvents such as N-methyl-2-pyrrolidone, N _, N-dimethylacetamide, and N,N-dimethylformamide; Examples include phenols such as m-cresol, dimethyl sulfoxide, etc., but are not limited thereto. Various epoxy resins can be used to modify the imide-based amino group-containing compound, but in order to improve the glass transition point and other properties of the resin after curing, novolac-type epoxy resins are recommended. It is preferable to use Of course, it is also possible to use other epoxy resins depending on the purpose of use. For example, using a brominated epoxy resin can improve the flame retardancy of the resulting resin. In that case, in order to achieve the UL standard UL94V-0, it is appropriate to blend the brominated epoxy resin in an amount that will contain 6% by weight or more of bromine atoms based on the total solid content of the composition. be. Examples of the above-mentioned brominated epoxy resin include:
Brominated novolak type epoxy resin () represented by the following general formula, diglycidyl ether compound of tetrabromo bisphenol A (), and brominated epoxy resin derived from tetrabromobisphenol A () [In the above formulas () and (), m represents a positive integer, and p represents 0 or a positive integer. ] etc. are mentioned as the most preferable examples, but the invention is not limited thereto. The above epoxy resins may be used alone or in combination. The blending ratio of the imide-based amino group-containing compound and the epoxy resin is not particularly limited, but as described above, in the present invention, it is possible to obtain sufficient interlayer adhesion even with a small blended amount of the epoxy resin. Therefore, from the viewpoint of increasing the glass transition point of the resin, the amount of the epoxy resin blended is preferably as small as possible. For example, in conventional epoxy-modified imide resin prepolymers, the weight ratio of epoxy resin/imide resin was often about 1.5, but in this invention, the weight ratio of epoxy resin/imide resin was approximately 1.5. Even if the amount of epoxy resin is reduced such that the amino group-containing compound is ≦1.0, sufficient interlayer adhesion strength can be obtained that is equal to or greater than that of the conventional method. In the present invention, at least an unsaturated imide compound is used as a curing agent for curing the epoxy resin. Typical unsaturated imide compounds include N-methylmaleimide, N-ethylmaleimide, N-phenylmaleimide, and the bismaleimide () shown below. and its derivatives are preferably used, but
Without being limited to these, many other unsaturated imide compounds can be used as well. These may be used alone or in combination. Further, as a curing agent other than the above-mentioned unsaturated imide compound, a Lewis acid compound consisting of a novolak type phenol resin and/or a novolak type cresol resin can also be used in combination. The curable resin composition of the present invention as described above can be obtained by simply mixing the imide group-amino group-containing compound, the epoxy resin, and the curing agent. When it is high, it appears to be uniform, but when diluted, there is a risk that the former two components will separate.
Therefore, it is preferable to react the imide group-amino group-containing compound and the epoxy resin under appropriate conditions. The reaction conditions are not particularly limited, and can be adjusted depending on the type of compound used, etc.
You can set them individually. Next, more detailed examples of the present invention will be described together with comparative examples. - Example 1 - Trade name as imido group amino group-containing compound a
TSM-20 (manufactured by Sumitomo Chemical Co., Ltd., bisphenol A type epoxy resin (manufactured by Yuka Ciel Epoxy Co., Ltd., handled by Ciel Chemical Co., Ltd., Epicote 828) and brominated epoxy resin (same as above) Using DX245 manufactured by Co., Ltd.,
After performing epoxy modification by reacting at 35° C. for 30 minutes, the bismaleimide () was added as a curing agent to obtain a curable resin composition. The blending amounts of each of the above components are as shown in Table 1. A glass cloth (WE-09-F104 manufactured by Nitto Boseki Co., Ltd.) was impregnated with the above curable resin composition and heated at 160°C for 10 minutes.
The prepreg was obtained by drying for a minute. Four sheets of the obtained prepreg were stacked and copper foil (JTC-18μ manufactured by Nikko Gould Co., Ltd.) was placed on top and bottom of the resulting laminate, which was heated and pressed at 30 kg/cm ² at 170° C. for 90 minutes. Thereafter, after-curing was performed at 200° C. for 120 minutes under normal pressure to obtain a double-sided copper-clad laminate (hereinafter referred to as “laminate”) with a thickness of 0.5 mm. -Example 2- A curable resin composition was prepared in the same manner as in Example 1 above, except that a novolac type cresol resin was used as a curing agent together with the above bismaleimide (), and a laminate was prepared in the same manner. was created. - Example 3 - Compound a (in the formula,

A curable resin composition was prepared in the same manner as in Example 1 above, except that R ₁ =R ₂ =H, m=1) was used in combination, and a laminate was also produced. -Comparative Example 1- Instead of the imide group-amino group-containing compound, N,
N′-diphenylmethane bismaleimide and 4,4′-
Example 1 above except that Kinel type polyimide obtained by reacting with diaminodiphenylmethane (DDM) was used and an amine curing agent (DDM) was used instead of the unsaturated imide compound as the curing agent. A curable resin composition was prepared in the same manner as above, and laminates were produced in the same manner. - Comparative Example 2 - Compound a (in the formula,

【formula】

【formula】

A curable resin composition was prepared in the same manner as in Example 1 above, except that p=q=1) was used, and laminates were produced in the same manner. - Comparative Example 3 - A curable resin composition was prepared in the same manner as in Example 1 above, except that the same compound a as in Example 4 was used as the imide group-amino group-containing compound, and the same procedure was followed. A laminate was produced. - Comparative Example 4 - Instead of unsaturated imide compound as curing agent
A curable resin composition was prepared in the same manner as in Example 1, except that DDM was used, and a laminate was produced in the same manner. Regarding the laminates of the above examples and comparative examples,
The following tests were conducted to evaluate the performance. *Glass transition point After removing the copper foil on the surface of the laminate by etching, it was measured using a dynamic viscoelasticity measuring device. ★ Interlayer adhesion strength Width 4 to 8 perpendicular to the fiber direction of glass cloth
The laminate was cut into strips of mm. The interlayer adhesion strength between the first layer and the second layer of the glass cloth in the obtained sample was measured using a Schottper type tensile tester. ★ Copper foil peel strength A sample similar to the above interlayer adhesion strength rate was prepared, and the peel strength between the copper foil on the surface and the first layer of glass cloth immediately below it was measured using a Schottsper type tensile tester. It was measured. ★Solder heat resistance The laminate was cut into 25±1 mm length and width test pieces, which were floated on a solution solder bath (300°C).
After 20 seconds, the presence or absence of blisters on the copper foil surface and the laminate was observed. The above results are also shown in Table 1.

【table】

〔Effect of the invention〕

The curable resin composition according to the present invention has a high glass transition point and good heat resistance, and when used in a laminate, it provides even better interlayer adhesion, which is unprecedented. It can be expected to be an excellent laminate material.

Claims (1)

[Claims] 1. An aromatic compound represented by the following general formula () or a product obtained by reacting an epoxy resin with an aromatic compound represented by the following general formula (), and an unsaturated imide as a curing agent. A curable resin composition containing a compound. [In the formula, Ar ₁ and Ar ₂ are each a divalent aromatic group,
R ₁ is a hydrogen atom or an alkyl group having 1 to 10 carbon atoms, R ₂ is a hydrogen atom, an alkyl group having 1 to 20 carbon atoms,
Each represents an alkoxyl group or a hydroxyl group, and n represents an integer from 0 to 80. ] [In the formula, Ar ⁴ represents a tetravalent aromatic group, R ¹ and R ² represent a hydrogen atom, a halogen atom, or an alkyl group, and at least one of R ¹ and R ² is always an alkyl group. Moreover, m represents a positive integer. 2. The curable resin composition according to claim 1, which also contains a Lewis acid compound consisting of a novolak type phenol resin and/or a novolak type cresol resin as a curing agent. 3. The curable resin composition according to claim 1 or 2, wherein the epoxy resin contains a brominated epoxy resin, and the amount thereof is 6% by weight or more in terms of bromine atom content in the total solid content.