JPS6282009A - Manufacture of prepreg - Google Patents

Abstract

PURPOSE:To prevent generation of voids in the outer layer and an inner layer after molding of a laminated sheet, by a method wherein rolls are brought into contact with both sides of a resin-impregnated base material by providing a plurality of rolls on a position excluding a gateway part out of the whole length of a drying process where the resin-impregnated base material flows. CONSTITUTION:Smoothness of both sides of a prepreg are improved by bringing both the sides of the prepreg into contact with several rolls during a drying process of the prepreg. Glass cloth 6 enters into a drying tower 7 after immersion in varnish 5 and passes through gaps among two sets of a top and bottom rolls 1, 3 and 2, 4. Each of the rolls 1, 2, 3, 4 is synchronized with the glass cloth and the glass cloth is compressed appropriately in each of the gaps among rolls 1, 3 and 2, 4. Each of the roll positions is obtained by excluding one fifth of the while length of the drying process from a gateway of the drying process.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Field of Application) The present invention relates to laminated FI2, especially steel-clad #i-layer plates, which are electrical insulation materials, and multilayer printed wiring boards. The present invention relates to a method for manufacturing prepreg used for manufacturing materials such as fabrics.

(Prior art) Lamination: FI impregnates a base material with a matrix resin, dries it, and then heats and presses the required number of sheets to form them.

Paper, glass cloth, glass vapor, cloth, etc. are used as the base material, and thermosetting resins such as epoxy resin, polyimide resin, phenol resin, polyester resin, melamine resin, and silicone resin are used as the n1 matrix resin.

The production of laminates involves placing mushroom material on a metal plate, stacking a head plate and stacking prepreg as required, then layering the head plate, mushroom material, and metal plate.The properties required for the prepreg are as follows. , the surface is smooth, and the resin impregnation is sufficient.

Conventionally, only one side of this type of prepreg was in contact with the roll during the drying process (see Figure 2).

(Problems to be Solved by the Invention) In the prepreg drying process, resin impregnation of the base material on the surface not in contact with the rolls is insufficient, resulting in unevenness instead of smoothness. For this reason, voids were generated in the surface layer and inner layer after the molding of the slope, which caused cracking after heating, and also caused defects in electrical properties and appearance.

(Means for Solving the Problems) In order to solve the above-described problems with prepregs, the present invention provides a method in which both sides can be made smooth to a certain extent and resin impregnated to a sufficient extent.

The present invention is a method of bringing both sides of the prepreg into contact with several rolls during the drying process to improve the smoothness of both sides. FIG. 1 shows an embodiment of the invention. glass cloth 6
After soaking in varnish 5, it enters the drying tower 7P9 and passes through two sets of upper and lower rolls 1.5 and 2,40 gaps. Each roll 1, 2
, 44 are synchronized with the glass cloth, and the glass cloth is appropriately compressed in the gaps between the rolls 1.6, 2, and 4. The position of each roll is 11 points along the entire length of the drying process from the entrance/exit of the drying process.
5 shall be excluded.

Example 100 parts of epoxy resin (Evomic R301 manufactured by Mitsui Petrochemicals, 11,480 g per epoxy) was dissolved in 25 parts of methyl ethyl ketone, 4 parts of curing agent dicyandiamide was dissolved in methyl cellosolve, and 2-ethyl-4-methyl imidazol was added to the above mixture. The varnish made by adding 2 parts of The roughness is shown in Table 1.

Comparative Example A prepreg was produced by conventional drying as shown in FIG. The surface roughness is shown in Table 1.

(Effects of the Invention) A prepreg sample obtained by an example of the present invention and a prepreg sample obtained by a conventional method in which only one side is brought into contact with a roll were compared in terms of plane roughness. The results are shown in Table 1.

Table 1

[Brief explanation of drawings]

FIG. 1 is an explanatory diagram of prepreg manufacturing according to the present invention, and FIG. 2 is an explanatory diagram of conventional prepreg manufacturing. 1, 2.3.4... Roll, 5... Varnish, 6...
・・・・・・・・・・・・Glass cloth, 7・・・・・・
・・・・・・・・・Drying tower. %1 Figure 2

Claims (1)

[Claims] 1. In the continuous manufacturing process of prepreg, in which a base material is impregnated with a thermosetting resin dissolved in an organic solvent and then dried, a plurality of rolls are installed at positions throughout the entire length of the drying process where the resin-impregnated base material flows, excluding the entrance and exit portions. A method for producing a prepreg, characterized in that the roll is in contact with both sides of a resin-impregnated base material.