JPS58193143A - Laminated board - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a laminate having excellent dimensional stability and interlayer adhesive strength.

Conventionally, for the purpose of improving dimensional stability, JP-A-56-1
A laminated plate shown in Japanese Patent No. 48549 is known. This laminate is a laminate made of cloth and resin woven from composite yarn made by mixing and twisting glass fibers with a fiber diameter of 5 to 7 μm and organic fibers with a fiber diameter of 5 to 7 μm and a heat resistance temperature of 160C or higher. The reason why the fiber diameter is limited in this way is that fibers with a diameter of less than 5 μm have low strength, and fibers with a diameter of more than 7 μm have poor resin impregnation properties.

However, when aromatic polyamide fibers are used as organic fibers, they are made of cloth and resin obtained by weaving a composite yarn made by mixing and twisting aromatic polyamide fibers and glass fibers with a fiber diameter similar to or larger than that of the aromatic polyamide fibers. Although laminates have the advantage of excellent dimensional stability, they also have the disadvantage of poor interlayer adhesion strength. The reason why the interlaminar adhesive strength of this laminate is poor is that the adhesive strength between the aromatic polyamide fiber and the resin is weak, so that the gaps between the cloths of the laminate tend to peel off.

An object of the present invention is to appropriately select the ratio of the fiber diameters of the aromatic polyamide fibers and the glass fibers in a laminate made of cloth and resin obtained by weaving a composite yarn made by mixing and twisting aromatic polyamide fibers and glass fibers. By this, the object is to provide a laminate with excellent dimensional stability and interlayer adhesive strength.

The feature of the present invention is that a resin is applied to a cloth obtained by weaving nine composite yarns by twisting a mixture of glass fibers and aromatic polyamide fibers having a fiber diameter 1.4 times larger than the diameter of the fibers. It is made by impregnation.

Note that the words "fiber diameter" and "fiber diameter" used above mean the diameter of one filament.

The present invention will be explained in detail below.

The bending stiffness S of a fiber with a circular cross section is expressed as: where d: Fiber diameter E: Elastic modulus of fiber The elastic modulus of aromatic polyamide fiber is 13360 and 4 f/w
m" (131, OGPa), and the elastic modulus of the glass fiber is 7400 Kff/wm" (720 Pa). Therefore, from equation (1), the ratio of the stiffness So of the glass fiber to the bending strength SF of the aromatic polyamide fiber having a diameter 1.4 times the fiber diameter of the glass fiber is as follows.

In this way, a composite yarn made by twisting a mixture of aromatic polyamide fibers with high bending rigidity and glass fibers with low bending rigidity has a structure in which the glass fibers are wound around the aromatic polyamide fibers. Therefore, many glass fibers having strong adhesive strength with resin are arranged on the surface of this composite yarn, and the interlayer adhesive strength of the laminate is strengthened.

In order to increase the interlayer adhesion strength of a laminate, it is desirable to increase the ratio of the bending stiffness of aromatic polyamide fibers and glass fibers as much as possible, and to wrap the glass fibers so as to cover the aromatic polyamide fibers. In order to increase the interlayer adhesive strength of the plate, the ratio of the bending stiffness of the aromatic polyamide fiber to the glass fiber must be at least 5 or more.

To obtain this bending stiffness ratio, the diameter of the aromatic polyamide fiber must be at least 1.3 times the fiber diameter of the glass fiber, but considering the variation in the fiber diameter of both fibers, the average of the aromatic polyamide fiber It is necessary to make the fiber diameter larger than 1.4 times the average fiber diameter of the glass fibers.

Next, the present invention will be specifically explained by showing examples.

Example 22 tex KEVLAFL 49 (DuPont registered trademark) aramid fiber (average fiber diameter 11.9 μm) y2
2 tex glass fibers (average fiber diameter 3 μm) are twisted together to make a single yarn, and this composite yarn is woven at a weaving density of 40 yarns.
I made a composite cloth of 40/25■.

On the other hand, brominated bisphenol A type epoxy resin (epoxy equivalent: 480 g/eq) 90 parts by weight, cresol novolac type epoxy resin (epoxy equivalent: 220 g/eq) 1
0 parts by weight, 4 parts by weight of dicyandiamide, 0.2 parts by weight of benzyldimethylamine, and methyl ethyl ketone and methyl celonorb as solvents were added to make a 37% concentration festival.9.

The above composite cloth was dipped in this fest, and 160C
The prepreg was dried for 5 minutes to obtain a prepreg.

Next, eight sheets of this prepreg and a copper foil having a thickness of 35 μm were placed on top of each other and pressed at 1701:1′ for 60 minutes to obtain a copper-clad laminate.

Comparative Example 1 A composite yarn was made by twisting 22 tex KEVLAR 49 aramid fibers (average fiber diameter 11.9 μm) and 22 tex glass fibers (average fiber diameter 13 μm), and this yarn was woven at a weaving density of 40 x 40/25 ■I made a composite cloth.

This composite cloth was dipped into the festival used in the example, and
A prepreg was obtained by drying at 0C for 5 minutes.

Next, eight sheets of this prepreg and copper foil with a thickness of 35 μm were placed on top of each other and pressed at 170 C for 60 minutes to obtain a copper-clad laminate.

Comparative Example 2 Glass fibers of 22 tex (average fiber diameter 9 μm) were produced to make a cloth with a weave density of 42×32 fibers/25M.

This cloth was immersed in the festival used in the example, and 160t
:' for 5 minutes to obtain a prepreg.

Next, eight sheets of this prepreg and copper foil having a thickness of 35 μf were placed one above the other and pressed at 170C for 60 minutes to obtain a copper-clad laminate.

Examples, comparative examples 1. Table 1 shows the performance of the laminate of Comparative Example 2.

Note that the dimensional change rate shown in Table 1 refers to the difference between the dimensions after manufacturing the laminate and the dimensions after copper foil etching and heat treatment.

As can be seen from the Examples and Comparative Examples in Table 1 and above, by appropriately selecting the ratio of the fiber diameters of aromatic polyamide fiber and glass fiber, a laminate with excellent dimensional stability and strong interlayer adhesion can be produced. can be provided.

Continuation of page 1 0 shots: Yasuo Miyadera Hitachi Chemical, 1500 Oaza Ogawa, Shimodate City Seikogyo Co., Ltd. Shimodate Research Institute 0 shots by Riki Matsuura Hitachi Chemical, 1500 Oaza Ogawa, Shimodate City Seikogyo Co., Ltd. Shimodate Research Institute ■Applicant: Hitachi Chemical Co., Ltd. 2-1 Nishi-Shinjuku, Shinjuku-ku, Tokyo No. 1

Claims (1)

[Claims] Laminating a predetermined number of prepregs obtained by impregnating a cloth obtained by weaving a composite yarn made by mixing and twisting glass fibers and aromatic polyamide fibers having a fiber diameter larger than 1.4 times the diameter of the fibers with a resin. A laminate plate made by heating and pressure forming.