JPH0339321A - Epoxy resin composition - Google Patents

Abstract

PURPOSE:To obtain the title composition useful as a resin for substrate of printed circuit board and adhesive, having heat resistance and sufficient bond strength without reducing curing properties, comprising a specific aromatic diamine and epoxy resin. CONSTITUTION:The aimed composition comprising an aromatic diamine {preferably 2,2-bis[3,5-dibromo-4-(beta-p-aminophenoxyethoxy)phenyl]propane} shown by the formula (X1-X4 are H, halogen or alkyl; R1 and R2 are H, methyl, ethyl, trifluoromethyl or trichloromethyl; n is 1-3) and an epoxy resin containing two or more epoxy groups in the molecule.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an epoxy resin composition using a specific amine compound as a curing agent. More specifically, the present invention relates to an epoxy resin composition that has excellent flame retardancy, flexibility, and adhesive properties and is useful as a resin for substrates of printed wiring boards and as a resin for adhesives.

(Prior art) The properties of the cured epoxy resin vary depending on the type of curing agent. For example, it has been reported that a cured epoxy resin using an aromatic diamine as a curing agent has excellent heat resistance. .

Aromatic diamines such as diaminodiphenylmethane are used as hardeners in epoxy resin compositions for printed wiring board substrates and adhesives to improve drill workability such as smear and soldering heat resistance after moisture absorption. There was a problem that the product was brittle and the adhesive strength with copper foil and interlayer adhesive strength decreased.

Methods for improving these include a method of using halogenated polyaminodiphenylmethane in combination with imidazoles or imidacillins as a curing agent for epoxy resins as shown in Japanese Patent Publication No. 49-23840, and Japanese Patent Application Laid-Open No. 62-62747.
A method using a halogenated aromatic polyamine as shown in Japanese Patent Publication No. 62-187737, and an aromatic diamine substituted with an alkyl group at the 2 and 6 positions and dicyandiamide There is a way to use both.

In addition, as a curing agent that improves the adhesive strength of epoxy resin by imparting flexibility to the cured product, 2,2-bis[3,5-dibromo-4 There is a method using -(4-aminophenoxy)phenylcopropane.

(Problems to be solved by inventions/devices) Special Publication Publication No. 1973-2
The method of using a halogenated aromatic amine or an alkylated aromatic amine as a curing agent for epoxy resin, which is shown in Japanese Patent Application Laid-open No. 3840, Japanese Patent Application Laid-Open No. 62-62747, and Japanese Patent Application Laid-Open No. 62-187737, is effective for adhesion with copper foil. Although the strength and interlayer adhesion are improved, this is due to the fact that the aromatic ring is substituted with a halogen or alkyl group, which reduces the reactivity of the amine group and the epoxy group. There was a problem in that when the curing properties were adjusted, the adhesive force naturally became insufficient.

On the other hand, in the case of the long-chain diamine disclosed in JP-A-58-8639, there is no substituent on the aromatic ring to which the amino group is bonded, so the reactivity with the epoxy group does not change and curability is a problem. However, since the cured resin product has insufficient flexibility, the adhesive strength with copper foil and the interlayer adhesive strength are also insufficient.

The present invention provides an epoxy resin composition that can improve adhesion to copper foil and interlayer adhesion without reducing curability.

(Means for Solving the Problems) As a result of intensive studies to solve the above problems, the present inventors found that by using a specific aromatic long-chain diamine as a hardening agent, there was no problem in hardenability and there was no problem with copper foil. It has been found that an epoxy resin composition with excellent adhesive strength and interlayer adhesive strength can be obtained.

That is, 1 the present invention is based on the general formula [1] % formula % [1] (wherein, , ethyl group, trifluoromethyl group or trichloromethyl group, which may be the same or different, n is an integer of 1 to 3) is used as a curing agent. The present invention will be described in detail below.

Epoxy resins used in the present invention include, for example, bisphenol A epoxy resins, phenol or talesol novolak epoxy resins, alicyclic epoxy resins, and halogenated resins thereof, which may be used alone or in mixtures.

The aromatic diamine curing agent that is a feature of the present invention has a structure represented by the above general formula [11], and specifically, 2,2-bis[4-(β-p-aminophenoxyethoxy) phenyl]propane, 2,2-bis[3,5-dibromo-4-(β-p-aminophenoxyethoxy)phenyl]propane, and the like, which can be used alone or in a mixture.

In addition to the aromatic diamine represented by the above general formula [1], compounds known as curing agents such as dicyandiamide, aliphatic diamine, and acid may be used as necessary, within a range that does not reduce heat resistance and adhesiveness. Anhydrides etc. can be used together, or if necessary, known compounds such as imidazoles, tertiary amines, quaternary ammonium salts, phosphine and quaternary phosphonium salts can be used together as curing accelerators. can.

In the present invention, the amount of the aromatic diamine represented by the above general formula [1] is preferably 0.5 to 1.2 equivalents in terms of active hydrogen equivalent to 1 equivalent of the epoxy resin, that is, the epoxy equivalent. When it is out of this range, various properties such as heat resistance, moisture resistance, and processability tend to deteriorate.

The epoxy resin composition of the present invention can be used as a varnish by diluting and dissolving the epoxy resin, the aromatic diamine represented by the general formula [11], and other curing agents and curing accelerators as necessary with a solvent. can. Moreover, various additives such as fillers and flame retardants can be used in combination as necessary.

The epoxy resin composition of the present invention can form an adhesive layer as it is or by applying the varnish to an adhesive and drying it. Additionally, a prepreg can be produced by impregnating and drying a base material such as glass fiber, and a laminate can be made by stacking and molding several sheets.

(Function) The epoxy resin composition of the present invention exhibits excellent performance in heat resistance, adhesiveness, and curability by using the aromatic diamine represented by the above general formula [1] as a curing agent, that is, the above-mentioned The aromatic diamine represented by the general formula [1] has a longer chain compared to known aromatic diamines, and by using it as a curing agent, a cured epoxy resin product with high flexibility can be obtained. It is thought that this improves adhesive strength.

In addition, since the aromatic ring to which the amino group is bonded is not substituted with other functional groups, the reactivity with the epoxy group does not decrease, and therefore the curability of the epoxy resin composition is also lower than that of conventional aromatic diamines. Nothing has changed and there are no problems.

(Example) The present invention will be explained in more detail with reference to Examples below.

Example 1 Brominated bisphenol A type epoxy resin (epoxy equivalent: 530) 80 parts by weight Phenol novolak type epoxy resin (epoxy equivalent: 200) 20 parts by weight 2.2-bis[4-(β-p-aminophenoxyethoxy)phenyl] 30 parts by weight of propane 0.5 parts by weight or more of 2-ethyl-4-imidazole was dissolved in methyl ethyl ketone to make a varnish with a non-volatile content of 60%, impregnated into a 0.1 mm thick glass cloth and heated at 140°C for 5 minutes. A prepreg was obtained. In order to examine the curing properties of this prepreg, gelation time (160° C.) was measured.

Next, three sheets of prepreg and 35 μm thick copper foil were laminated to form a
A copper-clad laminate was produced by molding for 60 minutes at 70°C and 50 kg/am. In order to evaluate the heat resistance and adhesiveness of this laminate, the solder heat resistance after moisture absorption (PCT/12
1℃-3hr + 260℃, 20 seconds) and copper foil peel strength (1mm width line, 50mm/mi
n) was measured.

Comparative Example 1 A prepreg and a copper-clad laminate were produced in the same manner as in Example 1 except that 5 parts by weight of dicyandiamide was used as a curing agent, and the gelation time, soldering heat resistance, and copper foil peel strength were measured. .

Comparative Example 2 A prepreg and a copper-clad laminate were produced in the same manner as in Example 1, except that 15 parts by weight of 2,2-bis(p-aminophenoxy)propane was used as a curing agent, and gelation time,
Solder heat resistance and copper foil peel strength after moisture absorption were measured.

Example 2 Bisphenol A type epoxy resin (epoxy equivalent: 500) 80 parts by weight Phenol novolac type epoxy resin (epoxy equivalent: 200) 20 parts by weight 2.2-bis[3,5-dibromo-4-(β-p-aminophenoxy) ethoxy)phenyl]propane
50 parts by weight 2-ethyl-4-imidazole 0
．． A varnish with a nonvolatile content of 60% was prepared by dissolving 5 parts by weight or more of the compound in methyl ethyl ketone, and a prepreg and an R-strung laminate were prepared in the same manner as in Example 1.
Solder heat resistance and copper foil peel strength after moisture absorption were measured.

Comparative Example 3 2,2-bis[3,5-dibromo-4-(
A prepreg and a copper-clad laminate were prepared in the same manner as in Example 2 except that 45 parts by weight of p-aminophenoxy)phenyl]propane was used, and gelation time, soldering heat resistance after moisture absorption, and copper foil peeling strength were measured. We measured the

Table 1 shows the measured values of the gelation time of the prepreg, the solder heat resistance of the copper clad laminate, and the peel strength of the copper foil.

(Effect of the invention) As is clear from the results in Table 1, the epoxy resin composition using the specific aromatic diamine of the present invention has excellent heat resistance,
Moreover, unlike conventional aromatic amines, it has sufficient adhesive strength for use in wiring boards without reducing curability, and is useful as a substrate resin or adhesive for printed wiring boards.

Table 1

Claims (1)

[Claims] 1. General formula [I] ▲There are mathematical formulas, chemical formulas, tables, etc.▼...[I] (In the formula, X_1 to X_4 represent hydrogen, halogen, or an alkyl group, and may be different from each other. R_1 and R_2 represent hydrogen, a methyl group, an ethyl group, a trifluoromethyl group, or a trichloromethyl group, and may be the same or different from each other. n represents an integer of 1 to 3.) An epoxy resin composition comprising an aromatic diamine and an epoxy resin having two or more epoxy groups in the molecule. 2. The aromatic diamine represented by the general formula [I] is 2,2
The epoxy resin composition according to claim 1, which is -bis[4-(β-p-aminophenoxyethoxy)phenyl]propane. 3. The aromatic diamine represented by the general formula [I] is 2,2
The epoxy resin composition according to claim 1, which is -bis[3,5-dipromo-4-(β-p-aminophenoxyethoxy)phenyl]propane.