JPS58193144A - 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 plate having a small linear expansion coefficient in the in-plane direction and a relatively small am tensile coefficient in the thickness direction.

Conventionally, for the purpose of improving dimensional stability, JP-A-56-1
A laminated board shown in Japanese Patent No. 48549 is known. This laminated board is made by mixing 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 1000 or higher. It is a board made of cloth woven from twisted composite yarns and resin, and 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 7 μm or more are impregnated with resin. It is a bad thing.

However, when aromatic polyamide fibers are used as organic fibers, cloth and resin are produced by weaving composite yarns 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. The laminated l-plate has the disadvantage of strong anisotropy in that the coefficient of linear expansion in the in-plane direction of the laminate is small, but the coefficient of linear expansion in the thickness direction of the laminate is large.

There are two main reasons for this, and they are that in laminated plates made of cloth and resin, fibers with a smaller coefficient of linear expansion than resin are oriented in the plane of the laminated plates. The plate has a structural difference in the in-plane direction and the plate thickness direction, and the aromatic polyamide fiber has anisotropy in linear expansion coefficient, which is as small as -2×10-@C-1 in the fiber axis direction. It has a linear expansion coefficient and a large a expansion coefficient of 59 x 10 "tl:" in the fiber radial direction.

The object of the present invention is to improve the above-mentioned drawbacks, and to provide a laminated board made of cloth and resin obtained by weaving nine composite yarns by twisting a mixture of aromatic polyand fibers and glass fibers.
By appropriately selecting the fiber diameter ratio of aromatic polyamide fiber and glass fiber, the in-plane linear expansion coefficient of the laminate is small, and the linear expansion coefficient in the thickness direction is also relatively small! - To provide a board.

The feature of the present invention is that the diameter of the glass fiber is 0.
A predetermined number of prepregs obtained by impregnating a resin with a cloth obtained by making JA fibers from composite yarns mixed and twisted with aromatic polyamide fibers having a fiber diameter of 7 times or less are molded under heat and pressure. It is.

The terms 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 follows. d: Fiber diameter E: Fiber elastic modulus The elastic modulus of aromatic polyamide fiber is 13360 Kpf/1
yaa” (131,0 GPa), and the elastic modulus of the glass fiber is.

The composite yarn, which is a mixture of twisted glass fibers with high bending rigidity and aromatic polyamide fibers with low bending rigidity, has a structure in which the aromatic polyamide fibers are wound around the circumference 9 of the glass fibers. For this reason, the aromatic polyamide fibers having a large anisotropy in the coefficient of linear expansion are bent, and the anisotropy in the coefficient of linear expansion of the laminate caused by the anisotropy in the coefficient of linear expansion of the aromatic polyamide fibers is alleviated.

In order to reduce the anisotropy of the wire and tenacity coefficients of the laminate, the ratio of the bending stiffness of the aromatic boriad fibers and the glass fibers should be made as small as possible, and the aromatic polyand fibers should be strongly bent and wound around the glass fibers. However, as shown in the examples described later, it has been found that it is effective to make the diameter of the aromatic boria-doped fibers 0.7 times or less the fiber diameter of the glass fiber.

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

Example 22 KEVLAR 49 (registered trademark of DuPont) aramid fiber (average fiber diameter 11.9 μm) and 22t
EX glass fibers (average fiber diameter 17 μm) were twisted together to make a composite yarn, and this yarn was woven to make a composite cloth with a weaving density of 40 pieces x 40 pieces/25 m.

On the other hand, 90 parts by weight of brominated bisphenol A epoxy resin (1480 g/eq of epoxy), 1 part of cresol novolak epoxy resin (220 g/eq of epoxy)
Add methyl ethyl ketone and methyl cellosolve as solvents to 0 parts by weight, 4 parts of dicyandiamide, and 0.2 parts of benzyldimethylamine to make a varnish with a concentration of 37%.9.

The above composite cloth was immersed in this varnish and heated to 160C.
The mixture was dried for 5 minutes to obtain a prepreg.

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

Comparative Example 22 KEVLAR 49 aramid fiber of tex (average M fiber diameter 11.94 m) and glass fiber of 22 tex (average fiber diameter 3 μm) were twisted together to make a composite yarn, and this yarn was woven to have a weaving density of 40 pieces x 40 pieces. / I made a 25m double cross.

In the center of this temporary cloth, 8 sheets of prepreg made using the varnish used in the example and 35 μm thick steel foil were placed on top and bottom, and pressed at 170C for 60 minutes to obtain the Copper Clad τ Award! - Obtained a board.

Table 1 shows the performance of the +yRrm board of the actual example and comparative example.

As can be seen from the above examples and comparative examples, by appropriately selecting the ratio of the fiber diameters of aromatic polyamide 1 fiber and glass fiber, the coefficient of linear expansion in the in-plane direction can be reduced, and the coefficient of linear expansion in the thickness direction can also be increased. Comparatively/J1 size no board can be provided.

Continuation of page 1 [Phase] Initiator: Yasuo Miyadera Hitachi Chemical, 1500 Bold Ogawa, Shimodate City Seikogyo Co., Ltd. Shimodate Research Institute 0 shots by Hide Matsuura Hitachi Chemical, 1500 Oaza Ogawa, Shimodate City Seikogyo Co., Ltd. Shimodate Research Institute 0 applicants Hitachi Chemical Co., Ltd. 2-1 Nishi-Shinjuku, Shinjuku-ku, Tokyo No. 1

Claims (1)

[Claims] A predetermined number of sheets of prepreg are fabricated by impregnating a cloth obtained by weaving a composite yarn made by mixing and twisting glass fibers with aromatic polyamide fibers having a fiber diameter of 0.7 times or less than the diameter of the fibers, and impregnating the cloth with a resin. , a product made by heating and pressure molding.