JPH05318653A - Manufacture of flame-retardant copper-clad laminate - Google Patents

Abstract

PURPOSE:To ensure that a flame-retardant copper-clad laminate of high quality is obtained which meets safety and environmental requirements by impregnating the sheet with a blend of bifunctional epoxy resin, dihydric phenols, a curing agent and aluminum hydroxide as essential ingredients, then laminating a prepreg obtained by chemical reaction with the bifunctional epoxy resin, divalent phenols and curing agent on a copper foil and molding these materials in one piece under heat and pressure. CONSTITUTION:A flame-retardent copper-clad laminate consists of bifunctional epoxy resin, divalent phenols, a curiang agent and aluminum hydroxide as essential ingredients. A prepreg is prepared by applying the essential ingredients to a base material and allowing the ingredients to undergo a chemical reaction in the B stage during the subsequent impregnation and drying processes, instead of applying, impregnating and drying a resin composition obtained by running the essential ingredients through a previous chemical reaction. The prepreg thus obtained is stacked on the copper foil and these materials are molded in one piece under heat and pressure. This flame-retardant copper-clad laminate, containing aluminum hydroxide in the resin, is perfect from a safety and environmental viewpoint, because water is adsorbed from aluminum hydroxide during the burning process and the adsorbed water is used for fire resistance.

Description

Detailed Description of the Invention

[0001]

The present invention does not contain bromine compounds,
The present invention relates to a method for producing a flame-retardant copper-clad laminate excellent in safety and measling resistance.

[0002]

2. Description of the Related Art In recent years, with the development of electronic equipment, printed circuit boards have come to be used in various fields, and most of the substrate materials are flame-retardant (UL9) for safety reasons.
4 V-0).

However, the conventional flame-retardant substrate uses a bromine compound such as a brominated epoxy resin for flame retardation. Although bromine compounds have a large flame retardant effect, combustion,
Due to thermal decomposition, toxic and irritating gas is generated,
Not safe. As described above, although the bromine compound is used for the flame-retardant substrate, it has a serious drawback such as generation of toxic gas.

[0004]

DISCLOSURE OF THE INVENTION The present invention has been made to solve the above-mentioned drawbacks, and is free of bromine compounds, excellent in safety and environment, and excellent in measling resistance and adhesiveness. Another object of the present invention is to provide a method for producing a flame-retardant copper-clad laminate.

[0005]

Means for Solving the Problems As a result of intensive research aimed at achieving the above-mentioned objects, the present inventors have found that a large amount of aluminum is contained in a resin, and a resin component is reacted during the production of a prepreg. The present invention has been completed by finding that the stable manufacturing method for the above purpose can be achieved.

That is, the present invention relates to a bifunctional epoxy resin, 2
A prepreg obtained by impregnating a mixture of the above essential components in a prepreg manufacturing process with a dihydric phenol resin, a curing agent and aluminum hydroxide as essential components and reacting the bifunctional epoxy resin, the dihydric phenols and the curing agent with copper. A method for producing a flame-retardant copper-clad laminate, which is characterized in that the foil is laminated with a foil and integrally molded under heat and pressure.

The present invention will be described in detail below.

The prepreg used in the present invention is obtained by coating and impregnating a base material with a mixture of a bifunctional epoxy resin, a dihydric phenol, a curing agent and aluminum hydroxide, and at the time of producing a prepreg, a bifunctional epoxy resin, a dihydric phenol and It is a reaction of a curing agent.

Examples of the bifunctional epoxy resin used for the prepreg include a bisphenol A type epoxy resin and a bisphenol F type epoxy resin, which can be used alone or in combination. If necessary, cresol novolac epoxy resin, phenol novolac epoxy resin, bisphenol A novolac epoxy resin, and other polyfunctional epoxy resins such as trifunctional and tetrafunctional compounds can be blended.

Examples of the dihydric phenols used in the prepreg include bisphenol A and methylene bisphenol, which can be used alone or in combination.

Examples of the curing agent used for the prepreg include dicyandiamides and phenols, and specific compounds of the phenols include phenol novolac, cresol novolac, and bisphenol A novolac. It is not limited. These can be used alone or in combination.
In addition, examples of the curing accelerator include imidazoles, tertiary ammonium salts, tertiary amines, and the like, and these can be used alone or in combination.

As the aluminum hydroxide used in the present invention, those which are usually used for laminated plates can be used, and the particle size and the like are not particularly limited, but those having a particle size of several μm which can be highly filled in operation are preferable.

The prepreg used in the present invention is not obtained by coating, impregnating and drying a base material with a resin composition prepared by preliminarily reacting each of the above components. It is produced by a B-stage reaction during impregnation and drying. The flame-retardant copper-clad laminate can be manufactured by stacking the prepreg and the copper foil thus obtained, heating and pressurizing, and integrally laminating.

[0014]

The flame-retardant copper-clad laminate according to the manufacturing method of the present invention is
By including aluminum hydroxide in the resin, water in the aluminum hydroxide is released at the time of combustion, and the water as a leaving component is used for flame retardancy, so there is no safety or environmental problem at all. In the conventional resin composition for lamination, epoxy resin and dihydric phenol A are reacted in a reaction vessel to polymerize, and then coated, impregnated and dried on a substrate to produce a prepreg. On the other hand, in the present invention, a mixture of low molecular weight components before the reaction is applied to improve the impregnation property into glass cloth and the like, and the B stage reaction of the respective components is promoted during the production of the prepreg, whereby the bifunctional By adopting a method that controls the competitive reaction between the epoxy resin, dihydric phenol and curing agent, the impact resistance and workability, which were the drawbacks of heat-resistant epoxy resin, have been greatly improved, and adhesion and measling resistance have been improved. It is an improvement.

[0015]

EXAMPLES The present invention will now be described with reference to examples. The invention is not limited by these examples. In the following examples and comparative examples, "part" means "part by weight".

Example 1 Bifunctional epoxy resin Epicoat 828 (manufactured by Yuka Shell Epoxy Co., trade name) 90 parts, multifunctional epoxy resin YDC
N704 (manufactured by Tohto Kasei Co., cresol novolac epoxy resin, trade name), 10 parts of bisphenol A, 6 parts of didiandiamide and 60 parts of methyl cellosolve were dissolved by heating to obtain a uniform solution. After cooling the solution, 2-ethyl-
4-methylimidazole 0.12 parts was added, and aluminum hydroxide Hydilite H31 (manufactured by Nippon Light Metal Co., Ltd.,
A varnish was prepared by adding 100 parts of the product name and thoroughly stirring with a disperse.

Silane-treated glass cloth was dipped in this varnish to apply and impregnate it, and dried in a vertical dryer to react the bifunctional epoxy resin with the dihydric phenol to produce a prepreg.

A plurality of the prepregs were stacked, copper foils were stacked on the front and back, and heated and pressed at a pressure of 40 kg / cm ² and a temperature of 180 ° C. for 2 hours to produce a flame-retardant copper-clad laminate.

Examples 2 to 4 Using the composition shown in Table 1, a prepreg was prepared in the same manner as in Example 1, and a flame-retardant copper-clad laminate was manufactured in the same manner as in Example 1.

Comparative Examples 1-2 A prepreg having the composition shown in Table 1 was prepared in the same manner as in Example 1, and a flame-retardant copper-clad laminate was manufactured in the same manner as in Example 1.

Using the flame-retardant copper-clad laminates produced in Examples 1 to 4 and Comparative Examples 1 to 2, glass transition temperature, copper foil peel strength, resistance to measling, flame retardancy, and generation of irritating odor gas. The results were shown in Table 1. The glass transition temperature was measured by the TMA method. Copper foil peel strength is 18μ
Tested with m 2 copper foil. The boiling resistance is 4
After a lapse of time, the product after being immersed in a solder bath at 260 ° C. for 30 seconds was visually evaluated. Flame retardance was tested by UL94. For the generation of irritating odor gas, the presence or absence of irritating odor gas during combustion was tested. The flame-retardant copper-clad laminate according to the present invention was excellent in all properties, and the effects of the present invention could be confirmed.

[0022]

[Table 1] * 1: Brominated bisphenol A epoxy resin (bromination rate
21%) Product name, manufactured by Chipa Geigy. * 2: Phenol equivalent of about 120. * 3: The surface prepreg used was one without Heidilite H31. * 4: After boiling for 4 hours, the product was immersed in a solder bath at 260 ° C for 30 seconds and visually evaluated. ○: No blister. * 5: ○: No occurrence.

[0023]

As is apparent from the above description and Table 1, the flame-retardant copper-clad laminate produced by the production method of the present invention does not contain a bromine compound and therefore does not generate a toxic gas.
It is excellent in safety and environment, and is highly reliable and flame retardant such as measling resistance.

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Claims (1)

[Claims] 1. A bifunctional epoxy resin, a divalent phenol, a curing agent and aluminum hydroxide as essential components,
In the prepreg manufacturing process, a prepreg obtained by impregnating the mixture of the above essential components and reacting a bifunctional epoxy resin, a dihydric phenol and a curing agent is laminated with a copper foil, and integrally molded by heating and pressurizing. A method for producing a flame-retardant copper-clad laminate.