JPH0258546A - Molding method for resin-impregnated fiber sheet molded products - Google Patents

Abstract

PURPOSE:To efficiently produce moldings excellent in appearance in a short time by put a mat consisting of continuous glass fiber on top of a resin- impregnated fiber sheet containing a quick-curing catalyst in a specified amount and pressing under heating. CONSTITUTION:(A) A sheet-like material composed of glass fiber is impregnated with a composition composed of 100 pts.wt. unsaturated polyester and 0.5-2.5 pts.wt. quick-curing catalyst (e.g., t-butyl peroxybenzoate or t-butyl peroxyisopropyl carbonate). (B) A continuous strand mat composed of continuous glass filament fibers is placed on a bottom tool of a pressing mold and a prescribed number of the resin-impregnated fiber sheets prepared by (A) are put on top of the mat in layers. The top force is then closed and pressing under heating is carried out under 50 kg/cm<2> at such mold temperatures as 140 deg.C at the top force and 130 deg.C at the bottom tool, thus obtaining a resin-impregnated fiber sheet molding.

Description

[Detailed description of the invention] (Industrial application field) The present invention is a resin-impregnated fiber sheet (hereinafter referred to as rsMc).

The present invention relates to a method of using a specific amount of a fast-curing catalyst to shorten the molding cycle and improve productivity during molding.

(Prior art and its section M) Various attempts have been made to improve the productivity and shorten the molding time in the conventional molding of SMC molded products, but none of them use ordinary curing catalysts. S was there
In MC, simply shortening the press mold clamping time will destroy the balance between the curing speed due to the flow of the unsaturated polyester resin in SMC and the mold clamping time, and the reinforcing glass fibers will be easily cut partially, causing the glass fibers to break. There was a gap where the effect of using it as a stronghold was lost.

(Means for solving Section H) The present invention is a method for solving the above-mentioned fat problem, and its gist is that 0.5 to 2.5 parts by weight of a fast-curing catalyst is added to 100 parts by weight of unsaturated polyester resin. This is a method for forming a resin-impregnated fiber sheet molded product, which comprises laminating a continuous glass fiber mat on a resin-impregnated fiber sheet obtained by impregnating a glass fiber sheet with a composition containing the above-mentioned composition, and hot pressing the laminated resin-impregnated fiber sheet.

The present invention will be explained in detail below.

The SMC used in the method of the present invention is made by adding a fast-curing catalyst to a composition made by adding additives such as a dispersant and filler to a common unsaturated polyester resin, and impregnating this into a glass fiber sheet. A glass fiber mat made of continuous long fibers is laminated on the SMC and heated and pressed.

The fast curing catalyst added to the composition in the above SMC includes 1,1-bis(t-butylperoxy)3,3.
Wotrimedylcyclohexane, 1,1-bis(t-butylperoxy)cyclohexane, t-butylperoxy(2-ethylhexanoate, t-butylperoxylaurate, t-butylperoxyisopropyl carbonate, etc.) Suitably used.

The above rapid curing catalyst is used in an amount of 0.5 to 2.5 parts per 100 parts by weight (hereinafter referred to as "parts") of the unsaturated polyester resin. If the amount added is less than 0.5 parts, the effect of shortening the curing speed will be small, and if it exceeds 2.5 parts, the surface of the molded product will become uneven in gloss, impairing the quality of its appearance.

In addition, in the present invention, the continuous glass fiber mat laminated on the SMC to which the above-mentioned fast-curing catalyst has been added is a continuous glass fiber mat made of continuous glass fibers in the form of long fibers, which is normally used for reinforcement in SMC molding. -It is an asstrand mat.

During press molding, the above-mentioned continuous glass fiber mat is placed on the lower mold of the press mold, a predetermined number of sheets of the above-mentioned fast-curing catalyst-added SMC are overlaid, and then the upper mold is closed, and the mold temperature is raised to above. Mold 140°C, lower mold 130°C, press pressure 5
Molding is carried out under the following molding conditions: Q kg, cJ, mold clamping time of 40 to 50 seconds, and pressure holding time of 240 to 250 seconds.

(Example) Compositions of Examples and Comparative Examples used in the present invention were prepared as 14I according to the formulations shown in Table 1 below.

The following margins> Ku Table -1>"Table-1> The composition of the embodiment shown in Table -1 is impregnated into a normal glass fiber mat, and it is aged for 24 hours at 40 ° C.
Four m+n SMC sheets (thickness 6M) are laminated on one continuous strand mat with a thickness of 0.5 threshold, and the total product pIJg is 6.5I+I11! The laminate is placed on the lower mold of the press mold, the upper mold is closed, and the temperature of the upper mold is increased to 140'C.
Pressing was carried out under the following conditions: 1 lower mold 130°C 1 pressure 50 kIr/cJ to obtain a panel with a thickness of 5 mm and good appearance quality.
In the example, the mold clamping time was 45 seconds, and the pressurization holding time was 240 seconds.
It was seconds. However, in the comparative example, the mold clamping time was 7
It took 5 seconds, and the pressure holding time was 330 seconds.

Next, when the above comparative example was press-molded under the same conditions as the mold clamping time and pressure holding time of the above-mentioned example, the balance between the curing speed and mold clamping time was lost, and continuous glass fiber ma.7+ for reinforcement was used. - The glass fibers were partially cut and the appearance was poor.

(Effect of the invention) Since the present invention has the above configuration, it has the following effects.

By the method of the present invention, SMC without adding a fast curing catalyst,
If continuous glass fiber mats are laminated and molded by synchronizing the curing speed of the resin in the SMC to shorten the mold clamping time, the glass fibers will not be cut during molding, resulting in a molded product with excellent appearance quality. The productivity of SMC molded products is improved by molding in just one hour.

Claims (1)

[Claims] A continuous glass fiber mat is laminated on a resin-impregnated fiber sheet obtained by impregnating a glass fiber sheet with a composition in which 0.5 to 2.5 parts by weight of a fast-curing catalyst is added to 100 parts by weight of an unsaturated polyester resin. A method for forming a resin-impregnated fiber sheet molded product, the method comprising heating and pressing.