JPS59174628A - Production of laminated plate - Google Patents

Abstract

PURPOSE:The base is, before being impregnated with a thermosetting resin, pretreated with a mixture of a water-soluble phenolic resin and a novolak type phenolic resin to give laminated plates with high dimensional stability, heat resistance and good punching properties. CONSTITUTION:At first, the base such as kraft paper is pretreated with a mixture of (A) a water-soluble phenolic resin and (B) a novolak type phenolic resin, preferably the content of component B is 20-60wt%, then impregnated with (C) a thermosetting resin, preferably modified with a drying oil. The products are dried and the resultant prepregs are laminated to give the objective plates. The resin B is preferably obtained by allowing formaldehyde to react with phenol so that the molar ratio is 0.1-0.4.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for manufacturing a laminate having excellent dimensional stability and heat resistance, as well as excellent punching workability, water resistance properties, and electrical properties.

In recent years, with the development of the electronic equipment industry, there has been a demand for higher density circuit boards, and significant advances in mounting systems have led to improvements in the dimensional stability and punching workability (interlayer adhesion) of the laminates used.
Excellent products are required.

Conventionally, the phenolic resin used for laminates is generally 1
It is a resol type resin whose core is methylolphenol. Although this resol type resin has the advantage of being excellent in impregnating the base material, it generates a lot of volatile matter such as condensed water and unreacted substances due to dehydration condensation reaction during the curing process.
The resulting laminate exhibits large shrinkage and expansion due to heating and moisture absorption, and its dimensional stability is unsatisfactory.

On the other hand, novolak-type phenolic resins are known to have superior dimensional stability compared to the resol-type phenolic resins, and novolak-type phenolic resins have poor impregnation properties into base materials (when used as a laminate, they have poor dimensional stability). Poor adhesion between material layers (problems with electrical properties, water resistance, etc.).

SUMMARY OF THE INVENTION An object of the present invention is to eliminate the above-mentioned conventional drawbacks and provide a laminate with good dimensional stability.

In order to achieve the above object, the present invention provides a method for manufacturing a laminate in which a prepreg obtained by impregnating and drying a thermosetting resin on a base material treated with Iiii+ with a water-soluble phenol resin is applied to the water-soluble phenol resin. It is characterized by using a mixture of novolac type phenolic resin.

The novolac type phenolic resin used in the present invention includes phenol, cresol, xylenol, butylphenol,
It is a reaction between phenols such as nonylphenol and formaldehydes such as formaldehyde and paraformaldehyde using an excess of the former relative to the latter under an acidic catalyst. The molar ratio of formaldehyde/phenols is preferably O1 to O4. If it is less than 0.1, the advantages of the novolac type phenol resin will not be exhibited, and if it exceeds 0.4, the resin molecular weight will increase and impregnating properties will be impaired. In addition, the water-soluble phenolic resin used in the present invention is prepared by combining phenols such as phenol, cresol, xylenol, butylphenol, and nonylphenol with formaldehydes such as formaldehyde and paraformaldehyde, and using an excess of the latter with respect to the former to form a basic catalyst. This is the low molecular weight product that was reacted below. The appropriate proportion of the novolac type phenol resin mixed with the water-soluble phenol resin is 20 to 60% by weight. If the amount of novolac type phenol resin mixed is too large, the impregnating property to the base material will be impaired. Also, if it is too small, the dimensional stability will not be effective.

After pre-impregnating a base material such as cotton linter paper or kraft paper with the above mixed resin and pre-drying it.

A prepreg is obtained by impregnating and drying a thermosetting resin.

The thermosetting resin used in the present invention 1 is not particularly limited, but it is preferably modified with drying oil or the like in order to improve the punching workability of the laminate.

A required number of the above prepregs are stacked, and if necessary, metal foil is further stacked on one or both sides, and heated and pressed to obtain a laminate or a metal foil-clad laminate.

Next, the present invention will be explained in detail.

Example phenol 500f and 8596 paraformaldehyde 3
8g of paratoluenesulfonic acid in the presence of 0.3F
After heating to 0 to 85°C and reacting for 4 hours, diluted with a mixed solvent of triene and methanol (1:l) to reduce the resin content to 5096.
A novolak type phenolic resin was obtained. This varnish is A
Use varnish.

Nonylphenol 110f and 3796 formalin 301
．． 85% paraformaldehyde 40f was heated to 80-85°C in the presence of trimethylamine 30f and reacted for 1 hour, then phenol 330f and 8596 paraformaldehyde 230F were added and reacted at 80-85°C for 3 hours, then diluted with methanol. A water-soluble phenol resin having a resin content of 50% was obtained. This varnish will be referred to as B varnish.

Synthetic resol (m-cresol 6596, p-cresol 35%) '1509 and 750f of tung oil were heated to 80-85°C in the presence of 0.9f of para-toluenesulfonic acid and reacted for 3 hours.

Next, add 24F of 2596 ammonia water, 300g of 85% formaldehyde and 100F of methanol.
It was made to react at 0-85 degreeC for 4 hours. Next, the mixture was concentrated under reduced pressure and diluted with a mixed solvent of toludiene and methanol (1:1) to obtain a tung oil-modified phenol resin with a fat content of 50%.

This varnish will be referred to as C varnish.

The above A varnish and B varnish were mixed in a ratio of A:B = 4:6 by weight, and this was impregnated into kraft paper with a thickness of 0.25 mm to a resin content of 2096. After pre-drying, varnish C was mixed. A prepreg of resin gold [15296] was obtained by impregnation and drying. Eight sheets of this prepreg were layered with a 35 micron thick adhesive-coated copper foil on one side at a temperature of 160°C and a pressure of 1.
Heat and press at 00 Kp/+m for 60 minutes to a thickness of 1.
A copper-clad laminate of 6 layers was obtained.

Its performance is shown in Table 1.

Comparative Example 1 A kraft paper with a thickness of 0.25 mm was impregnated with varnish B to a resin content of 20%, and after preliminary drying, varnish C was impregnated and dried to obtain a prepreg with a resin gold Ω of 52%.

Using this prepreg, a copper-clad laminate was obtained under the same conditions as in the example.

Its performance is shown in Table 1.

Comparative Example 2 A prepreg with a resin adhesion content of 52% was obtained by impregnating 025 mm thick kraft paper with C varnish and drying it. Using this prepreg, a copper-clad laminate was obtained under the same conditions as in the example. Its performance is shown in Table 1.

Table 1 As mentioned above, in the present invention, the base material is pretreated with a water-soluble phenolic resin mixed with a novolac type phenolic resin, and then the prepreg which is impregnated with a thermosetting resin and dried is laminated and molded, so that good interlayer adhesion is achieved. The industrial value of this method is extremely great because a laminate with excellent electrical properties, water resistance properties, and dimensional stability can be obtained.

Claims (1)

[Scope of Claims] 1. In the production of a laminate in which prepregs obtained by impregnating and drying a thermosetting resin on a base material pretreated with a water-soluble phenolic resin are laminated and molded, a novolak-type phenolic resin is added to the water-soluble phenolic resin. A method for manufacturing a laminate, characterized by mixing. 2 Mixing ratio of novolac type phenolic resin is 20 to 60
% by weight. A method for producing a laminate according to claim 1.