JPH06190850A - Method for molding unit plate of fiber-reinforced plastic - Google Patents

Abstract

PURPOSE:To obtain a method for molding a unit plate of fiber-reinforced plastic without a glass break phenomenon or a glass levitation phenomenon with a higher weatherability and a higher productivity. CONSTITUTION:An outer surface-side prepreg 12 of a continuous strand mat impregnated with a resin compound obtained by compounding an unsatd. polyester resin with an inorganic filler and a curing agent is disposed on one mold 11 for forming an outer surface of a unit plate. On the outer surface-side prepreg 12, a rear surface-side prepreg 13 of a chopped glass roving impregnated with a resin compound obtained by compounding an unsatd. polyester resin with an inorganic filler and a curing agent realizing a curing rate higher than the curing agent compounded in the outer surface-side prepreg is disposed. In this state, the other mold 14 is closed, and the prepregs are heated and pressed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for forming a fiber reinforced plastic unit plate, and more particularly to a method for forming a water tank unit plate forming a water tank by using a resin-impregnated fiber sheet (SMC).

[0002]

2. Description of the Related Art As shown in a sectional view of FIG. 2, a conventional fiber reinforced plastic (FRP) unit plate is manufactured by a lower mold 1
The continuous strand mat 2 not impregnated with resin is placed on top of it, and the chopped glass roving 3 impregnated with resin is further laminated thereon, the upper mold 4 is closed, and heating / pressurization is applied to continue. A method of impregnating a strand component with a resin component under pressure is adopted. In this case, the side on which the continuous strand mat is arranged is usually used as the outer surface.

[0003]

However, in the case of the above manufacturing method, when the continuous strand mat 2 is pressure-impregnated with the resin component, the continuous strand mat 2
In some cases, the continuous strand mat 2 was broken due to insufficient strength, and the initial performance could not be exhibited. In addition, since the continuous strand mat 2 is impregnated with the resin component only by pressurization, the continuous strand mat 2 cannot be sufficiently impregnated with the resin component, which causes a phenomenon of so-called glass float. It may occur. Further, when the resin content on the surface is small, the weather resistance is poor, and there is a problem that the resin content is eluted by natural exposure and the glass fiber is exposed.

Therefore, an object of the present invention is to provide a method for molding a fiber-reinforced plastic unit plate which eliminates the phenomenon of glass breakage and glass floatation, and can improve weather resistance and productivity.

[0005]

In order to achieve the above-mentioned object, a method for molding a fiber-reinforced plastic unit plate of the present invention is such that one of the molds forming the outer surface of the unit plate is provided with an unsaturated polyester resin, An outer surface side prepreg in which a continuous strand mat is impregnated with a resin compound containing an inorganic filler and a curing agent is arranged, and the unsaturated polyester resin, the inorganic filler and the outer surface side prepreg are placed on the outer surface side prepreg. It is characterized in that a back side prepreg in which a chopped glass roving is impregnated with a resin compound containing a curing agent faster than the compounded curing agent is placed, and the other mold is closed and heated and pressed in this state.

[0006]

The present invention will be described in more detail below with reference to an embodiment shown in FIG. As shown in the cross-sectional view of FIG. 1, the molding method of the fiber reinforced plastic unit plate of the present invention is as follows. First, in one mold (lower mold) 11, a resin compound is formed into a glass fiber mat of a continuous strand mat. One to two plies of the impregnated outer surface side prepreg 12 are arranged. This outer surface side prepreg 12 is a prepreg manufacturing machine, in which a resin compound of the following formulation (A) is coated on a thermoplastic resin film such as polyethylene or polypropylene which runs on an endless belt conveyor, and the continuous compound is applied thereon. It can be produced by stacking the strand mat and the other thermoplastic resin film, followed by defoaming impregnation with a defoaming roll, and then heating at 40 ° C. for 24 hours for aging and thickening.

Blend (A) Unsaturated polyester resin 80 parts by weight Low shrinkage resin 20 parts by weight Curing agent (eg t-butyl perbenzoate) 1 part by weight Internal mold release agent (eg zinc stearate) 5 parts by weight Filler ( For example, calcium carbonate) 120 parts by weight Pigment 3 parts by weight Thickener (eg zinc oxide) 0.7 parts by weight

Next, on the outer surface side prepreg 12,
The outer prepreg 12 is a back prepreg 13 in which a chopped glass roving is impregnated with a resin compound.
The same as or more than the above is laminated and arranged. In the prepreg manufacturing machine, the back side prepreg 13 is
A resin compound of the following formulation (B) is coated on a thermoplastic resin film such as polyethylene or polypropylene running on an endless belt conveyor, and a glass cut into a predetermined length, for example, 1 inch by a roving cutter on the resin compound. Sprinkle roving (chopped glass roving). Then, the thermoplastic resin film coated with the resin compound of the same composition (B) is superposed, defoamed and impregnated with a defoaming roll in the same manner as described above, and then heated to be aged and thickened to be manufactured. it can.

Blend (B) Unsaturated polyester resin 80 parts by weight Low shrinkage resin 20 parts by weight Curing agent (eg t-butylperoxy isopropyl carbonate) 1 part by weight Internal release agent (eg zinc stearate) 5 parts by weight Filling Agent (eg calcium carbonate) 120 parts by weight Pigment 3 parts by weight Thickener (eg zinc oxide) 0.7 parts by weight

Then, in this state, the other mold (upper mold)
By closing 14 and heating and pressurizing under conditions of, for example, an upper mold 140 ° C., a lower mold 130 ° C. and a pressure of 50 kg / cm ² , the outer surface side prepreg 12 and the back side prepreg 13 are integrated to obtain a water tank unit plate. .

Here, in both of the above resin compounds, the curing agent used for the back side prepreg 13 is one that is faster in hardening than the one for the outer surface side prepreg 12. That is, when molding a thick one such as an aquarium unit plate, the curing rate of the outer layer is faster than the curing rate of the inner layer, so styrene gas or entrapped air remains in the inner layer and is molded. Although a large swelling may occur on the surface of the product and the phenomenon of glass fiber rising may occur, by increasing the curing speed of the back side prepreg 13, it is possible to prevent gas and air from being trapped. It is possible to prevent the outer surface from bulging and the glass fibers from rising. As the fast-curing curing agent, a fast-curing catalyst such as t-butyl peroctoate, t-butyl perbenzoate or peroxyketal may be used.

[0012]

As described above, according to the method for molding a fiber-reinforced plastic unit plate of the present invention, quality defects such as glass breakage and glass floatation do not occur, and
Since the thickness of the resin on the surface of the unit plate is increased, the weather resistance is also improved. Further, since the glass breakage phenomenon does not occur even when high-speed mold clamping is performed, the molding cycle can be shortened and the productivity is improved.

[Brief description of drawings]

FIG. 1 is a sectional view showing an embodiment of a molding method of the present invention.

FIG. 2 is a cross-sectional view showing an example of a conventional molding method.

[Explanation of symbols]

11 ... Mold (lower mold), 12 ... Outer surface side prepreg, 13 ...
Back side prepreg, 14 ... Mold (upper mold)

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Claims (1)

[Claims] 1. An outer surface side prepreg in which a resin compound containing an unsaturated polyester resin, an inorganic filler and a curing agent is impregnated into a continuous strand mat is disposed on one of the molds forming the outer surface of the unit plate. Then, on the outer surface side prepreg, a back side prepreg obtained by impregnating chopped glass roving with a resin compound containing an unsaturated polyester resin, an inorganic filler, and a curing agent faster curing than the curing agent mixed in the outer surface side prepreg. Is placed, and the other mold is closed and heated and pressed in this state, and a method for molding a unit plate made of fiber reinforced plastic.