JPS6213793Y2 - - Google Patents

Description

[Detailed explanation of the idea]

This invention is based on glass fiber reinforced plastic (hereinafter referred to as
This invention relates to a glass strand mat suitable as a reinforcing material for FRP. Glass strand mats that are currently widely used as reinforcing materials for FRP include glass chopped strand mats (hereinafter referred to as chopped strand mats) and glass contained strand mats (hereinafter referred to as contained strand mats). For chopped pine, the laminating resin (unsaturated polyester resin, epoxy resin, etc.) must have excellent wet-out properties during hand lay-up molding, and from the viewpoint of mold conformability, the resin must be treated with an easily soluble surface treatment. Often used are chopped strands bonded to resin in a mat shape using a readily soluble binder. FRP products reinforced with this chopped mat have the characteristics of good surface finish and high strength, but when used as a reinforcing material in mechanical molding methods such as press molding and resin injection molding, the resin wets out quickly. As a result, the strands quickly turn into filaments, resulting in high resin flow resistance, and furthermore, the binder dissolves in the resin, causing strand flow and mat breakage, making it impractical. In order to solve this problem, it was considered that chopped strands, which had a surface treatment that made them difficult to dissolve in resin, were made into a mat using an insoluble binder, but this method had good wet-through properties and strands. It is extremely difficult to manufacture a bulky pine that does not cause drift or pine cutting, and has not yet been put to practical use. On the other hand, continuous smuts, which are used in mechanical molding methods such as press molding and resin injection molding, are made by coiling continuous strands that have been surface-treated to make them difficult to dissolve in resin, and are made with an insoluble binder. It is made from a bulky pine tree. Although this container mat has good wet through and is less likely to cause strand drift or breakage, it is difficult to obtain a high-strength FRP product and has the problem of poor surface finish due to its many surface irregularities. In order to solve the problems of the conventional glass strand mat mentioned above, the inventors of the present invention have made extensive studies and have developed a glass strand mat having a three-layer structure in which both surface layers are made of chopped mat and the middle layer is made of continuous mat. The chopped strand layer has been subjected to a surface treatment that makes it soluble in resin, and the continuous strand layer is poorly soluble in resin and has a styrene-insoluble content of 30% to 90%.
It was discovered that the following surface treatment gives good wet through of the resin during mechanical molding, no strand flow or breakage occurs, and the appearance of the molded product is good, leading to the present invention. The present invention will be explained below with reference to the drawings. The glass strand mat shown in Figure 1 is made by bonding glass chopped strands with a cut length of 50 m/m on both surfaces into a mat shape using an easily soluble binder.
Chopped pine layer 1 with a mass of gram/1 square meter, the middle layer is poorly soluble in resin and has a styrene insoluble content of 40
It has a three-layer structure with a total mass of 600 g/1 square meter formed from a continuous mat layer 2 with a mass of 300 g/1 square meter bonded in a mat shape with a continuous strand binder that has been subjected to a surface treatment of . This glass strand pine is impregnated with an unsaturated polyester resin and press-molded to obtain an FRP board.The middle layer of the three-layered pine is surface-treated to have a styrene insoluble content of less than 30% (A). , surface treated with styrene insoluble content of 90% or more (b) and conventional 600g/
Table 1 shows a comparison of the characteristics (c) of an FRP board obtained by impregnating a 1 square meter container mass with unsaturated polyester resin and press-molding it. The middle layer of the three-layered pine contains styrene-insoluble content.
If the surface treatment is less than 30%, the pine will break or the strands will flow, and the styrene insoluble content will be 90%.
Whitening phenomenon can be seen on FRP boards that have been subjected to the above surface treatments. In addition, FRP boards using container mats have low bending strength and the finished surface of the molded product is uneven and has a poor appearance, but the glass strand mat according to the present invention has excellent properties in all respects.

【table】

[Table] <Forming conditions> Three plies of various glass strand mats weighing 600 g/m ² were placed in a press mold for flat plates at 60°C, and an unsaturated polyester resin solution containing 1% hardening agent was applied to the mats, and a press pressure of 5 kg was applied. /cm ² , mold clamping time
Press molding was performed for 20 minutes. The reason why we limited the insoluble content of the surface treatment agent of the container mat that constitutes the intermediate layer in the glass strand mat of the present invention to a range of 30 to 90% is as follows.
When a surface treatment agent with a styrene-insoluble content of 90% or more is applied, the impregnation with the liquid resin is slow from the time the liquid resin is applied or injected until it is molded and cured, and the initial strand form is maintained. If the chopped mats in both surface layers have a low mass because they are incorporated into the molded product, unevenness will occur on the surface of the molded product, worsening the appearance of the molded product. When the insoluble content of the surface treatment agent is 30% or less, the surface treatment of the continuous strand is easily dissolved in the liquid resin and becomes a filament, which obstructs the flow of the applied or injected liquid resin. Glass flow also occurs at the same time, resulting in a problem that the strength of the molded product lacks uniformity. As a method for insolubilizing the surface treatment of continuous strands of the present invention, the composition of the surface treatment agent is a mixture of an unsaturated polyester and an organic peracid oxide such as benzoyl peroxide or t-butyl perbenzoate, or an epoxy resin. It can be obtained by applying a mixture of curing agents such as diethylenetriamine or metaxylene diamine or a mixture of reactive vinyl acetate and acrylic silane, but is not limited to the examples given here. In this invention, the insoluble matter in styrene refers to the addition of a polymerization inhibitor (hydroquinone, etc.) to styrene at a rate of 0.1
%, surface-treated glass strand products are added thereto, and after reflux extraction for 12 hours, the amount of surface treatment agent remaining on the surface of the glass strand product is measured. The ratio of the residual content after extraction to the amount is indicated.

[Brief explanation of the drawing]

Figure 1 shows one of the glass strand mats of the present invention.
It is a cross-sectional schematic diagram showing an example. Brief explanation of the symbols: 1...Glass chopped strand mat layer, 2...Glass continuous strand mat layer.

Claims (1)

[Claims for Utility Model Registration] 1 Glass chopped strands are laminated in a glass strand mat having a three-layer structure in which both surface layers are formed of glass chopped strand mats and the middle layer is formed of glass continuous strand mats. A glass strand that has been subjected to a surface treatment that makes it soluble in a resin used for use, and the glass continuous strand has been subjected to a surface treatment that has a styrene-insoluble content of 30% or more and 90% or less. Matsuto. 2. The glass strand mat according to claim 1, wherein the continuous strand has been subjected to a surface treatment containing a crosslinked adhesive component as a main component. 3. The glass strand mat according to claim 2, wherein the crosslinked adhesive component is a cured unsaturated polyester resin. 4. The glass strand mat according to claim 2, wherein the crosslinked adhesive component is a cured epoxy resin. 5. The glass strand mat according to claim 2, wherein the crosslinked adhesive component is a reaction product obtained by subjecting a polyvinyl acetate resin to a crosslinking reaction with a silane coupling agent.