JPH0478647B2 - - Google Patents

Description

[Detailed description of the invention]

[Technical Field] The present invention relates to a curable resin composition used for laminates and the like. [Background technology] 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 is whether the number of laminated layers is 10 or more or less than 10, and either imide resin or epoxy resin is used.
However, in recent years, the uses of such laminates have become diversified, and the current usage system, such as the use according to the number of laminated plates, is no longer able to adequately cope with these needs. For example, epoxy resins are required to be superior in terms of high purity, fast curing, smearing properties, UV shielding properties, etc., and imide resins are required to have high glass transition temperature (Tg) and high There has been a growing demand for flame retardancy, low temperature curing, and cost reduction. Particularly recently, there has been a demand for products with performance that lies between those of imide resins and epoxy resins, and as a response to this demand, epoxy-modified imide resin polymers, which are made by modifying imide resin prepolymers with epoxy resins, have been developed. . However, many of the epoxy-modified imide resin prepolymers currently in use contain a large amount of epoxy resin in order to increase the interlayer adhesion when made into a laminate, but this results in a large amount of epoxy resin being added to the resin after curing. The problem is that the glass transition temperature becomes low. [Object of the Invention] The present invention was made in view of the above circumstances, and provides a curable resin composition that has a high glass transition temperature and can provide sufficient interlayer adhesion even when formed into a laminate. is intended to provide. [Disclosure of the Invention] In order to achieve the above objectives, the inventors conducted studies from the viewpoint of how to increase interlayer adhesion without increasing the amount of epoxy resin blended. . As a result, instead of increasing the amount of epoxy resin blended, we developed an aromatic compound that has multiple imide groups in the molecule, which is the main skeleton of the imide resin prepolymer, and a compound that has multiple amino groups that react with the epoxy resin. I found out that it can be used. However, simply reacting such a compound (hereinafter referred to as "aromatic compound having multiple imide groups and amino groups in the molecule") with an epoxy resin leaves many unreacted amino groups. It was found that this had a negative effect on heat resistance. Therefore, as a result of further study, this invention was completed. That is, the present invention provides a curable product which is obtained 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 blending at least an unsaturated imide compound as a curing agent. The main subject is resin compositions. This invention will be explained in detail below. Aromatic compounds having a plurality of imide groups and a plurality of amino groups in the molecule, which are used in place of the imide resin prepolymer, include the following formula (),
At least one of the compounds represented by () is used. [In the above formula, Ar ¹ represents a divalent aromatic group, Ar ² represents a tetravalent aromatic group, and Ar ³ represents a trivalent aromatic group, respectively, and n and m are 0 or a positive integer (however, n+
m>0). ] [In the above formula, Ar ⁴ represents 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,
At least one of R ¹ and R ² is always an alkyl group. Further, p represents a positive integer. ] The compound represented by the above general formula () includes dimethylformamide, N-methylpyrrolidone, m
- In a polar solvent such as cresol, the following general formulas () and () An aromatic acid anhydride represented by the following is reacted with an aromatic diamine represented by the following general formula () NH ₂ −Ar ¹ −NH ₂ ……() in excess of the number of moles of these acid anhydrides. It can be obtained by letting Examples of the aromatic acid anhydride represented by the general formula () or () include 3,3',4,4'-benzophenonetetracarboxylic dianhydride, pyromellitic dianhydride, 2,3,6, 7-naphthalenetetracarboxylic dianhydride, 3,3',4,4'-diphenyltetracarboxylic dianhydride, 2,2-bis(3,4-dicarboxyphenyl)propane dianhydride, bis (3,4-dicarboxyphenyl)ether dianhydride, 2,6-dichloronaphthalene-
1,4,5,8-tetracarboxylic dianhydride, phenanthrene-1,8,9,10-tetracarboxylic dianhydride, 1,1-bis(2,3-dicarboxyphenyl)ethane dianhydride , bis(2,3-dicarboxyphenyl)methane dianhydride, bis(3,4-dicarboxyphenyl)sulfone dianhydride, 1,1,3,3,3-hexafluoro-2,
Examples include 2-bis(3,4-dicarboxyphenyl)propane dianhydride and trimellitic anhydride. Examples of the diamine represented by the general formula () include 4,4'-diaminodiphenylpropane, 4,
4'-diaminodiphenyl methane, 4,4'-diaminodiphenyl sulfide, 3,3-diaminodiphenyl sulfone, 4,4'-diaminodiphenyl sulfone, 4,4'-diaminodiphenyl ether,
3,3'-dimethyl-4,4'-diaminodiphenylmethane, 3,3'-diethyl-4,4'-diaminodiphenylmethane, 3,3'-dimethoxy-4,4'-
Diaminodiphenylmethane, 3,3'-dimethyl-
4,4'-diaminodiphenyl ether, 3,3'-
Diethoxy-4,4'-diaminodiphenyl sulfone, 3,3'-diethyl-4,4'-diaminodiphenylpropane 3,3'-dimethyl-4,4'-diaminobenzophenone, 3,3'- Diaminodiphenyl methane, 3,3'-diaminodiphenyl ether,
2,4-diaminotoluene, 2,6-diaminotoluene, 2,4-diaminoanisole, 2,4-
Diaminomonochlorobenzene, 2,4-diaminofluorobenzene, m-phenylenediamine, p
-phenylenediamine, 3,3'-diaminobenzophenone, 1,3-bis(3-aminophenoxy)benzene, 9,9-bis(4-aminophenyl)fluorene, and the like. The reaction may be carried out under known polymerization conditions for producing imide polymers or amide-imide polymers. The compounds represented by the above general formula () include pyromellitic acid, 3,3',4,4'-benzophenonetetracarboxylic acid, 3,3',4,4'-diphenylethertetracarboxylic acid, 3 , 3',4,4'-biphenyltetracarboxylic acid, 2,3,6,7-naphthalenetetracarboxylic acid, 2,3,4,5-thiophenetetracarboxylic acid, 2,2-bis(3,
Aromatic tetracarboxylic acids such as (4-dicarboxyphenyl)propane and derivatives thereof, molar excess of o-alkyl substituted aniline-formaldehyde condensates (alkyl is C ₁ to C ₄ , of which ethyl group is preferred), etc. and an aromatic diamine component in a suitable solvent. As a solvent, N-methyl-2-pyrrolidone, N,
In addition to amide solvents such as N-dimethylacetamide and N,N-dimethylformamide, phenols such as m-cresol, dimethyl sulfoxide, etc. are used. Epoxy resins used for modifying aromatic compounds having a plurality of imide groups and a plurality of amino groups in the molecule, each represented by the above formulas () and (), include:
Although various resins are conceivable, it is preferable to use a novolak type epoxy resin in order to improve the glass transition temperature of the resin after curing and other properties. However, it is of course also possible to use other epoxy resins. For example, the use of brominated epoxy resins can improve the flame retardancy of the resin. In that case, UL
In order to achieve the standard UL94V-0, the brominated epoxy resin should be blended in an amount such that Br atoms are contained in an amount of 8% by weight or more based on the total amount of resin components. As the brominated epoxy resin, for example, the following general formula () Brominated novolac epoxy resin expressed by the formula () A diallyl etherified product of tetrabromobisphenol A represented by the formula () Diglycidyl etherified products of tetrabromobisphenol A represented by the following formula are preferred for this invention. The blending ratio of the aromatic compound having a plurality of imide groups and amino groups in the molecule and the epoxy resin is not particularly limited, but as described above, in this invention, even if the blending ratio of the epoxy resin is small, it is sufficient. The lower the blending ratio of the epoxy resin is, the more preferable it is from the viewpoint of increasing the glass transition temperature of the resin, since it is possible to obtain interlayer adhesion. For example, in conventional epoxy-modified imide resin prepolymers, the blending ratio E/I of epoxy resin (E) and imide resin (I) was often about 1.5, but in this invention, the epoxy resin (E) Even if the compounding ratio E/IA of the aromatic compound (IA), which has multiple imide groups and amino groups in the molecule, is 1.0 or less, it is possible to obtain the same interlayer adhesion as before. be. An unsaturated imide compound is used as a curing agent for curing the epoxy resin. A typical unsaturated imide compound is the following general formula () N-methylmaleimide represented by the formula () Bismaleimide represented by is preferably used, but unsaturated imide compounds other than these can of course also be used. In addition, curing agents other than the above unsaturated imide compounds,
For example, it is also possible to use a Lewis acid compound in combination. A typical Lewis acid compound is the general formula (XI) below. Phenol novolak expressed by formula (XII) [However, in the above two formulas, r and s represent an integer of 1 or more. ] Orthocresol novolacs and the like represented by these are preferably used, but Lewis acid compounds other than these can also be used. The curable resin composition of the present invention as described above can be obtained by simply mixing the above-mentioned aromatic compound having a plurality of imide groups and amino groups in the molecule, an epoxy resin, and a curing agent. However, if only mixed in this way, it will appear to be homogeneous if the concentration is high, but there is a risk that the former two will separate when diluted. Therefore, it is necessary to react an aromatic compound having a plurality of imide groups and a plurality of amino groups each in the molecule with an epoxy resin. The reaction conditions are not particularly limited, and may be set according to the type of compound used. Next, examples of the present invention will be described together with comparative examples. Examples 1 and 2 A compound represented by the above formula () was used as an aromatic compound having a plurality of imide groups and a plurality of amino groups in the molecule, and this was mixed with the epoxy resin shown in Table 1 and reacted. After that, a curing agent shown in the same table was added to obtain a curable resin composition. The obtained curable resin composition was coated on a glass cloth (manufactured by Nittobo Co., Ltd.).
WE-09-F104) and dried at 160°C for 10 minutes to obtain a prepreg. Obtained prepreg 4
Copper foil (JTC-
18μ), heated at 30Kg/cm ² and 170℃ for 90 minutes,
After applying pressure, after-curing was performed at 200° C. for 120 minutes under normal pressure to obtain a double-sided copper-clad laminate with a thickness of 0.5 mm. Examples 3 and 4 A curable resin was prepared in the same manner as in Examples 1 and 2, except that the compound represented by the above formula () was used as the aromatic compound having a plurality of imide groups and a plurality of amino groups in the molecule. The composition was obtained, and a double-sided copper-clad laminate with a thickness of 0.5 mm was produced. Comparative Example 1 A double-sided copper-clad laminate was obtained in the same manner as in Examples 1 and 2 above, except that no curing agent was blended. Comparative Examples 2, 3 Maleic acid N, N'-4, which is an unsaturated bisimide
The procedure was repeated in the same manner as in Examples 1 and 2 above, except that an imide compound containing a terminal amino group obtained by reacting 4'-diphenylmethane-bis-imide with 4,4'-diaminodiphenylmethane, which was a diamine, was used. A double-sided copper-clad laminate was obtained. The following tests were conducted on the double-sided copper-clad laminates obtained in the above Examples and Comparative Examples to evaluate their performance. The results are shown in the lower column of Table 1. <Glass transition temperature (Tg)> After the copper foil on the surface of the double-sided copper-clad laminate was removed by etching, it was measured using a dynamic viscoelasticity measuring device. <Interlayer adhesion strength> The double-sided copper-clad laminate was cut into strips having a width of 4 to 8 mm at right angles to the fiber direction of the glass cloth to obtain sunflutes. Then, the interlayer adhesive strength between the first layer and the second layer of glass cloth in the obtained sample was measured using a Schottper type tensile tester. <Copper Foil Peel Strength> A sample similar to the interlayer adhesive strength 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 Schottper type tensile tester. <Solder heat resistance> Cut a double-sided copper-clad laminate into a test piece of 25 ± 1 mm in length and width, float it on a molten solder bath (300°C), and after 20 seconds, check for blisters on the copper foil surface and the laminate. observed.

〔Effect of the invention〕

As described above, the curable resin composition of the present invention has a high glass transition temperature and can also provide sufficient interlayer adhesion even when formed into a laminate.

Claims (1)

[Scope of Claims] 1. Curing 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 adding at least an unsaturated imide compound as a curing agent. The aromatic compound having a plurality of imide groups and a plurality of amino groups each in the molecule has the following general formula ().
A curable resin composition comprising at least one of the following. [In the above formula, Ar ¹ is a divalent aromatic group, Ar ² is a tetravalent aromatic group, and Ar ³ is a trivalent aromatic group, respectively,
Expression, n and m are 0 or positive integers (however, n
+m>0). ] [In the above formula, Ar ⁴ represents 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,
At least one of R ¹ and R ² is always an alkyl group. Further, p represents a positive integer. 2. The curable resin composition according to claim 1, which also contains a Lewis acid compound as a curing agent. 3. The epoxy resin according to claim 1 or 2, wherein the epoxy resin contains a brominated epoxy resin, and the amount thereof is 8% by weight or more in terms of the Br atom content in the entire resin. Curable resin composition.