JPH0796533A - Method of molding frp molded product - Google Patents

Abstract

PURPOSE:To improve weather resistance without exposing glass fibers, by a method wherein an outside prepreg which is obtained by impregnating a nonwoven fabric material with a resin compound and a rear side prepreg which is obtained by impregnating a chopped glass roving with the same resin compound are heated and pressurized by interposing a continuous strand mat of glass fibers between them. CONSTITUTION:An outside prepreg 3 which is obtained by impregnating a nonwoven fabric material with a resin compound consisting mainly of unsaturated polyester resin or vinyl ester resin and a rear side prepreg 5 which is obtained by impregnating a chopped glass roving with a resin compound similar to the resin compound are heated and pressurised by interposing a continuous strand mat 4 made of glass fibers between them. In other word, the outside prepreg 3 is provided in a bottom force 1 and after the continuous strand mat 4 of the glass fibers is put in that, the rear side prepreg 5 which is obtained by impregnating the chopped glass roving with the resin compound is superposed. Then the mold 2 is clamped.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an FRP molded product molded from a resin-impregnated sheet, and more particularly to a method for molding an FRP molded product which is preferably used as a unit plate for a water tank.

[0002]

2. Description of the Related Art Conventionally, an FRP molded product used as a unit plate for a water tank has a chopped glass roving impregnated with a resin placed on a continuous strand mat containing no resin and heated. Method of integrating by pressure, method of placing non-woven fabric not impregnated with resin on chopped glass roving impregnated with resin and heating and pressing to integrate, and continuous glass on the surface of sheet molding compound A method is known in which a glass substrate such as a fiber mat or glass cloth is heated and pressed to be integrated.

[0003]

However, the FRP molded product obtained by the conventional molding method is, for example, a continuous strand mat, a non-woven fabric or a glass used as the outer surface side when used as a unit plate for a water tank. The base material side is not sufficiently impregnated with resin, so-called glass floating phenomenon occurs, and if the resin content is low, the weather resistance is poor, the resin content is eluted by natural exposure, and the glass fiber is exposed. There is a problem that the deterioration is further accelerated.

[0004]

DISCLOSURE OF THE INVENTION The present invention is intended to solve the above problems, and its gist is the outer surface side of a nonwoven fabric material impregnated with a resin compound mainly composed of an unsaturated polyester resin or a vinyl ester resin. Molding method of FRP molded article, characterized in that heat and pressure are applied through a continuous strand mat made of glass fiber between a prepreg and a back side prepreg in which chopped glass roving is impregnated with the same resin compound as the resin compound. Also, a resin compound similar to the resin compound is chopped glass between the outer surface side prepreg obtained by impregnating a nonwoven fabric material with a resin compound mainly composed of an unsaturated polyester resin or a vinyl ester resin and a continuous strand mat made of glass fiber. Impregnating roving The method for molding an FRP molded article, which comprises heating and pressurizing the back side prepreg, and the amount of the inorganic filler added to the resin compound impregnated in the outer surface side prepreg in the resin compound impregnated in the back side prepreg. Molding method of FRP molded article characterized by being less than the amount of inorganic filler and surface of sheet molding compound formed by impregnating chopped glass roving with resin compound mainly composed of unsaturated polyester resin or vinyl ester resin Of a FRP molded article, which comprises heating and pressing a prepreg obtained by impregnating a mesh woven cloth, which is fixed and reinforced so that the threads constituting the woven cloth are not displaced, with a resin compound similar to the sheet molding compound. There is a molding method.

[0005]

EXAMPLES The present invention will be described in more detail based on the following examples.

As shown in the cross-sectional view of FIG. 1, a method for molding an FRP molded product such as an FRP unit plate of the present invention is as follows. First, one lower mold 1 is provided with a thermosetting resin compound such as glass fiber or polyester fiber. One ply of the outer surface side prepreg 3 impregnated with the nonwoven fabric material is placed.

This outer surface side prepreg 3 is obtained by applying a resin compound having the following composition (A) onto a thermoplastic resin film such as polyethylene or polypropylene which runs on an endless belt conveyor in a prepreg manufacturing machine, and coating it on it. , The non-woven fabric material and the other thermoplastic resin film are overlaid, and after defoaming impregnation with a defoaming roll, for example, 40 ° C.
It is produced by heating for 24 hours, aging and thickening.

Blend (A) Unsaturated polyester resin 80 parts by weight Low shrinkage resin (polystyrene monomer solution) 20 parts by weight Curing agent (t-butyl perbenzoate) 1 part by weight Internal mold release agent (zinc stearate) 3 parts by weight Filler (calcium carbonate) 50 parts by weight Pigment 3 parts by weight Thickener (magnesium oxide) 0.8 parts by weight Next, one ply of glass fiber continuous strand mat 4 is placed on the outer surface prepreg 3. After doing
1 or more plies of back side prepreg 5 in which chopped glass roving is impregnated with resin compound are laminated and arranged.

In the prepreg manufacturing machine, the back side prepreg 5 is obtained by first coating a resin compound of the following composition (B) on a thermoplastic resin film such as polyethylene or polypropylene which runs on an endless belt conveyor, and coating it on it. A chopped glass roving cut into a predetermined length, for example, 1 inch by a roving cutter is sprayed.

Then, the thermoplastic resin films coated with the resin compound of the same composition (B) are superposed, and after defoaming and impregnating with a defoaming roll in the same manner as described above, the mixture is heated to be aged and thickened. To manufacture. The resin compound with which the outer surface prepreg 3 is impregnated may use the same composition (B) as the back prepreg 5, but the resin used in the back prepreg 5 with an inorganic filler amount as in the composition (A). It is more preferable that the amount of the inorganic filler in the compound is less than that of the compound because the impregnating property into the nonwoven fabric can be improved and the weather resistance can be improved. In this case, the amount of the inorganic filler in the compound (A) is preferably 20 to 70 parts by weight.

Blend (B) Unsaturated polyester resin 80 parts by weight Low shrinkage resin (polystyrene monomer solution) 20 parts by weight Curing agent (t-butyl peroxybenzoate) 1 part by weight Internal release agent (zinc stearate) 5 parts by weight Part Filler (calcium carbonate) 120 parts by weight Pigment 3 parts by weight Thickener (magnesium oxide) 0.8 parts by weight In this state, the other upper mold 2 is closed, for example, upper mold 140 ° C., lower mold The outer surface side prepreg 3, the continuous strand mat 4, and the back side prepreg 5 are integrated with each other by heating and pressurizing at 130 ° C. and a pressure of 50 kg / cm ² to obtain an FRP molded product for a water tank unit plate.

The thus-obtained FRP molded product has a resin layer having a thickness of 0.2 to 0.7 mm formed on the surface thereof and is free from appearance defects such as exposure of the glass fiber of the continuous strand mat 4 and deterioration of gloss. Moreover, the glass fiber is not exposed even after long-term natural exposure, and the weather resistance is extremely good.

A vinyl ester resin can also be used as the resin compound.

FIG. 2 shows another embodiment. First, one ply of a continuous strand mat 4 of glass fiber is placed on one lower mold 1 and an unsaturated polyester resin and cured on it. One or more plies of back side prepreg 5 obtained by impregnating chopped glass roving with a resin compound containing an agent and an inorganic filler such as calcium carbonate are placed. This back side prepreg 5 is a prepreg manufacturing machine, in which a resin compound of the following formulation (C) is coated on a thermoplastic resin film such as polyethylene or polypropylene which runs on an endless belt conveyor, and a roving cutter is used to predetermined it. After being cut to a length of, for example, 1 inch and sprayed with chopped glass roving, thermoplastic resin films coated with the same compound (C) resin compound are superposed on each other, followed by defoaming impregnation with a defoaming roll, For example, it can be produced by aging at 40 ° C. for 24 hours and increasing the viscosity.

Blend (C) Unsaturated polyester resin 80 parts by weight Low shrinkage resin (polystyrene monomer solution) 20 parts by weight Curing agent (t-butyl peroxybenzoate) 1 part by weight Internal mold release agent (zinc stearate) 5 parts by weight Part Filler (calcium carbonate) 120 parts by weight Pigment 3 parts by weight Thickener (magnesium oxide) 0.8 parts by weight Next, on the back side prepreg 5, the amount of the inorganic filler is smaller than that of the back side prepreg 5. One surface of the outer surface side prepreg 3 in which a resin compound of the following composition (D) mainly composed of unsaturated polyester resin is impregnated into a glass surface mat or a nonwoven fabric of organic fiber such as polyester or acrylic is placed, and in this state, on the other side Close the mold 2, for example, upper mold 2, 140 ℃, lower mold 1, 130 ℃,
By heating and pressurizing under a pressure of 50 kg / cm ² , the outer surface side prepreg 3, the back side prepreg 5 and the continuous strand mat 4 of glass fiber are integrated to obtain an FRP molded product for an aquarium unit plate. The FRP molded product thus obtained does not have a defective appearance such as exposure of continuous strand mud or nonwoven fabric and deterioration of gloss like the above-mentioned examples, and a resin layer having a thickness of 0.2 to 0.7 mm is formed on the surface. Therefore, the glass fiber is not exposed to long-term natural exposure, and the weather resistance is extremely good.

Blend (D) Unsaturated polyester resin 80 parts by weight Low shrinkage resin (polystyrene monomer solution) 20 parts by weight Curing agent (t-butylperoxybenzoate) 1 part by weight Internal mold release agent (zinc stearate) 3 parts by weight Parts Filler (calcium carbonate) 50 parts by weight Pigment 3 parts by weight Thickener (magnesium oxide) 0.8 parts by weight The amount of the inorganic filler added to the formulation (C) is 70 to 1
Add 50 parts by weight.

On the other hand, the compound (D) has a smaller number of added parts than the amount of the inorganic filler of the compound (C),
20 to 70 parts by weight is preferable because it has the same thickening property as the backside prepreg for the reasons of workability, prepreg hardness, etc., as in the case of the above-mentioned formulation (A).

By adjusting the amount of the filler of the compound (D) within the above range, the fluidity of the compound is increased, the impregnation property of the glass fiber or the organic fiber into the nonwoven fabric is increased, the choking phenomenon is reduced, and the weather resistance is improved. It is preferable because it can be improved.
A vinyl ester resin can also be used as the resin compound.

Also in this embodiment, the compound of the resin of the outer surface side prepreg 3 may be the compound (C). However, as in the case of the compound (D), the inorganic compound in the resin compound to be impregnated in the back side prepreg is used. It is more preferable to reduce the amount of the agent for the above reason.

Next, another embodiment will be described with reference to FIG.

An uncured sheet molding compound (SMC) 7 having an uncured thickness of 2 mm was prepared by impregnating chopping roving glass of reinforcing glass fiber with a resin compound compounded as described below.

Blend (E) Unsaturated polyester resin 80 parts by weight Low shrinkage resin (polystyrene monomer solution) 20 parts by weight Curing agent 1 part by weight Internal release agent (zinc stearate) 5 parts by weight Filler (calcium carbonate) 110 Parts by weight Pigment 5 parts by weight On the other hand, a resin-like material similar to that described above was impregnated into a knitted woven glass woven fabric to prepare an uncured reticulated prepreg sheet 6 of 0.5 mm.

Next, the laminated body in which the mesh prepreg sheet 6 is laminated on the above-mentioned four-layered SMC 7 is placed on the lower mold 1 and the upper mold 2 and the lower mold 1 under the following conditions. By heating and pressurizing, an FRP container having a height of 5 cm, a length of 30 cm, a width of 25 cm, a side wall thickness of 3 mm, and a bottom plate thickness of 5 mm was obtained.
A vinyl ester resin may be used as the resin compound.

Molding conditions Mold temperature Upper mold 140 ° C. Lower mold 130 ° C. Molding pressure 50 kg / cm ² Pressing time 5 minutes Continuing, the SMC molded product of the present invention was exposed to accelerated weathering by a sunshine weather meter (3 months exposure). A test was conducted to evaluate the weather resistance.

As a comparative sample, a general-purpose SMC molded product in which a glass woven fabric was not laminated on the surface of the molded product was used.

As a result, a general-purpose SMC molded product is
It was found that the reinforcing glass fiber inside was exposed on the surface and surface deterioration was severe.

On the other hand, the SMC molded product of the present invention is
It was found that the exposure of the glass fiber inside the SMC did not occur at all and the weather resistance was remarkably improved.

It is important that the entangled woven net-like woven fabric should not be opened or cut when it is pressure-laminated with SMC. Woven thread entanglement is strong and tensile strength is high, and a woven fabric having a thickness of 0.3 mm is effective. A mesh-like woven fabric in which the weft threads and the warp threads of the woven material are woven so that the weft threads are pressed against the warp threads from above and below at the intersecting points, and which is physically fixed and reinforced, is desirable. Alternatively, the glass members may be fixed and strengthened with a polyester or vinyl acetate adhesive.

A vinyl ester resin can also be used as the resin compound.

[0030]

As described above, according to the molding method of the present invention, the appearance of the continuous strand mat or non-woven fabric or the glass fiber of the glass substrate on the surface of the FRP molded product at the time of molding is exposed and the gloss is reduced. Since there is no defect and the resin layer having a predetermined thickness is provided on the surface of the FRP, there is no exposure of the glass fiber to long-term natural exposure, and an FRP molded article having extremely excellent weather resistance can be obtained.

[Brief description of drawings]

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

FIG. 2 is a sectional view showing another example of the molding method of the present invention.

FIG. 3 is a sectional view showing another example of the molding method of the present invention.

[Explanation of symbols]

 1 Lower mold 2 Upper mold 3 Outer surface side prepreg 4 Continuous strand mat 5 Back side prepreg 6 Reticulated prepreg sheet 7 SMC

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Claims (4)

[Claims] 1. An outer surface side prepreg obtained by impregnating a nonwoven material with a resin compound mainly composed of an unsaturated polyester resin or a vinyl ester resin, and a back side prepreg obtained by impregnating chopped glass roving with the same resin compound as the resin compound. A method for molding an FRP molded article, which comprises heating and pressing through a continuous strand mat made of glass fiber therebetween. 2. A resin similar to the above resin compound between the outer surface side prepreg obtained by impregnating a nonwoven fabric material with a resin compound mainly composed of unsaturated polyester resin or vinyl ester resin and a continuous strand mat made of glass fiber. A method for molding an FRP molded article, which comprises heating and pressing through a back side prepreg in which a compound is impregnated in chopped glass roving. 3. The amount of inorganic filler added to the resin compound impregnated in the outer surface prepreg according to claim 1 or 2 is smaller than the amount of inorganic filler in the resin compound impregnated in the back prepreg. The method for molding an FRP molded article according to claim 1 or 2, wherein 4. A sheet molding compound formed by impregnating chopped glass roving with a resin compound mainly composed of an unsaturated polyester resin or a vinyl ester resin. A method for molding an FRP molded article, which comprises heating and pressing a prepreg obtained by impregnating the reticulated woven fabric with a resin compound similar to the sheet molding compound.