JP2639113B2 - Epoxy resin composition - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to an epoxy resin composition using a specific amine compound as a curing agent. More specifically, flame retardant, flexible,
The present invention relates to an epoxy resin composition having excellent adhesiveness and useful as a resin for a substrate of a printed wiring board and a resin for an adhesive.

(Prior art) Epoxy resins vary in their properties 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 a curing agent in printed circuit board resins and epoxy resin compositions for adhesives to improve drill workability such as smear and solder heat resistance after moisture absorption. There is a problem that the material is brittle and the adhesive strength to the copper foil and the interlayer adhesive strength are reduced.

To improve these, a method in which halogenated polyaminodiphenylmethane is used in combination with imidazoles or imidazolines described in JP-B-49-23840 as a curing agent for an epoxy resin is disclosed in JP-A-62-62747. A method using a halogenated aromatic polyamine and 2,6,6
There is a method in which an aromatic diamine whose position is substituted with an alkyl group is used in combination with dicyandiamide.

Further, as disclosed in JP-A-58-8639, 2,2-bis [3,5-dibromo-4] is used as a curing agent for imparting flexibility to a cured product to improve the adhesive strength of an epoxy resin. − (4
-Aminophenoxy) phenyl] propane.

(Problems to be Solved by the Invention and Invention) Halogenated aromatic amines and alkylated aromatic amines described in JP-B-49-23840, JP-A-62-62747 and JP-A-62-187737. Is used as a curing agent for epoxy resin, although the adhesion to copper foil and interlayer adhesion are improved, but the reactivity of amino and epoxy groups is reduced due to the substitution of aromatic rings with halogens and alkyl groups. Therefore, when the curability is adjusted by using imidazole or dicyandiamide in combination, there is a problem that the adhesive strength naturally becomes insufficient.

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

The present invention provides an epoxy resin composition that can improve the adhesive strength to a copper foil and the interlayer adhesive strength without lowering the curability.

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

That is, the present invention provides a compound represented by the general formula [I]: (Wherein, X _{1 to} X ₄ represent hydrogen, an alkyl group, or halogen;
They 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. n shows the integer of 1-3. This is an epoxy resin composition characterized by using an aromatic diamine represented by the formula (1) as a curing agent, and the present invention will be described in detail below.

The epoxy resin used in the present invention includes, for example, bisphenol A type epoxy resin, phenol or cresol novolak type epoxy resin, alicyclic epoxy resin and halogenated resin thereof, and used alone or as a mixture.

The aromatic diamine curing agent which is a feature of the present invention has a structure represented by the above general formula [I], 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, and these can be used alone or in a mixture.

In addition to the aromatic diamine represented by the above general formula [I], if necessary, a compound known as a curing agent such as dicyandiamide, an aliphatic diamine and an acid may be used as long as heat resistance and adhesiveness are not reduced. An anhydride or the like can be used in combination, or if necessary, a compound known as a curing accelerator, such as an imidazole, a tertiary amine, a quaternary ammonium salt, a phosphine, and a quaternary phosphonium salt can be used in combination.

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

The epoxy resin composition of the present invention is obtained by diluting and dissolving the epoxy resin, the aromatic diamine represented by the above general formula [I], and other curing agents and curing accelerators as necessary with a solvent to use as a varnish. Can be. Various additives such as a filler and a flame retardant can be used in combination as needed.

The epoxy resin composition of the present invention can form an adhesive layer as it is or by applying the varnish to an adherend and drying. Further, a prepreg is produced by impregnating and drying a substrate such as glass fiber, and several sheets can be laminated to form a laminate.

(Action) The epoxy resin composition of the present invention has the general formula [I]
By using the aromatic diamine represented by the formula (1) as a curing agent, it shows excellent performance in heat resistance, adhesiveness and curability.
That is, the aromatic diamine represented by the above general formula [I] is a long-chain aromatic diamine as compared with a known aromatic diamine, and by using this as a curing agent, an epoxy resin cured product having high flexibility is obtained. Is considered to improve the adhesive strength.

In addition, since the aromatic ring to which the amino group is bonded is not substituted with another functional group, the reactivity with the epoxy group does not decrease, and therefore, the curability of the epoxy resin composition is also lower than that of the conventional aromatic diamine. There is no change and there is no problem.

(Example) Hereinafter, the present invention will be described more specifically with reference to examples.

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] Propane 30 parts by weight 2-Ethyl-4-imidazole 0.5 part by weight The above compound is dissolved in methyl ethyl ketone to form a varnish having a nonvolatile content of 60%, and impregnated in a 0.1 mm thick glass cloth at 140 ° C.
For 5 minutes to obtain a prepreg. The gel time (160 ° C.) was measured to examine the curability of the prepreg.

Next, three prepregs and 35 μm thick copper foil were laminated and 17
Molding was performed at 0 ° C. and 50 kg / cm ² for 60 minutes to produce a copper-clad laminate. In order to evaluate the heat resistance and adhesiveness of this laminate, solder heat resistance after moisture absorption (PCT / 121 ℃ -3hr + 260 ℃, 2
0 seconds) and copper foil peeling strength (1mm width line, 50mm / m
in) was measured.

Comparative Example 1 A prepreg and a copper-clad laminate were prepared 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, solder heat resistance, and copper foil peeling strength were measured. .

Comparative Example 2 A prepreg and a copper-clad laminate were prepared 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. Were measured for solder heat resistance and copper foil peeling strength.

Example 2 Bisphenol A type epoxy resin (Epoxy equivalent 500) 80 parts by weight Phenol novolak 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 0.5 part by weight The above compound was dissolved in methyl ethyl ketone to form a varnish having a nonvolatile content of 60%, and a prepreg and a copper-clad laminate were prepared in the same manner as in Example 1. It was manufactured, and the gel time, the solder heat resistance after moisture absorption, and the copper foil peeling strength were measured.

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

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

(Effects 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 and lowers curability like a conventional aromatic amine. It has sufficient adhesive strength for wiring boards without
It is useful as a resin for printed circuit boards and an adhesive.

Claims (3)

(57) [Claims] 1. A compound of the general formula [I] (Wherein, 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. May be the same or different. N represents an integer of 1 to 3) and an epoxy resin having an epoxy resin having two or more epoxy groups in a molecule. . 2. An aromatic diamine represented by the general formula [I]:
The epoxy resin composition according to claim 1, which is 2,2-bis [4- (β-p-aminophenoxyethoxy) phenyl] propane. 3. An aromatic diamine represented by the general formula [I]:
The epoxy resin composition according to claim 1, which is 2,2-bis [3,5-dibromo-4- (β-p-aminophenoxyethoxy) phenyl] propane.