JPH04329129A - Glass fiber reinforced synthetic resin molded product - Google Patents

Abstract

PURPOSE:To provide a glass fiber reinforced synthetic resin molded product characterized by that a glass fiber does not stimulate the skin uppon the touch with the surface of the molded product. CONSTITUTION:A glass fiber reinforced synthetic resin molded product A has such a structure that an air permeable sheet 4 composed of a reticulated body is integrally fixed to the surface of a molded body formed into a plate shape by bonding glass fibers 1 by a synthetic resin binder 2 by the curing of said binder 2. For example, the synthetic resin binder 2 is composed of polyethylene or polypropylene to mutually bond the glass fibers 1. The air permeable sheet 4 is composed of the reticulated body having a mesh size 1/10-1/2 the length of the glass fibers.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to improvements in synthetic resin molded products reinforced with glass fibers.

0002

[Prior Art] Conventionally, synthetic resin molded products in which glass fiber is mixed to strengthen bending strength are generally referred to as FRP, and are often used as synthetic resin materials with high bending rigidity, and their uses are wide-ranging. It has passed to In particular, FRP materials using short fibers have excellent workability and are used, for example, in automobile parts, concrete formwork materials, and the like.

0003

[Problems to be Solved by the Invention] However, in the above-mentioned glass fiber reinforced resin molded products, it is difficult to reduce the weight by incorporating a large amount of glass fiber with a long fiber length, or to add moldability by using glass fiber with a short fiber length. As a result, the following problems arose. In other words, if a large amount of glass fiber with a long fiber length is mixed in, the glass fibers will not be buried sufficiently inside the synthetic resin molded body, and the glass fibers will be easily exposed on the surface of the molded body, causing the surface of the molded body to become rough. When handling, exposed glass fibers may come into contact with the skin and cause irritation.

[0004] Furthermore, when fibers with short lengths are used, the bonding force between the glass fibers and the synthetic resin binder is reduced.
After the exposed glass fibers were stuck in the skin, they easily fell out of the molded body and remained stuck in the skin, causing not only itching but also pain.

[0005] On the other hand, as a method to prevent skin irritation caused by such shedding of glass fibers, it is possible to provide a protective layer by coating the surface of the molded product with a resin or by pasting a resin sheet. However, resin coating must be applied to each molded product, which is inefficient.Furthermore, since the glass fibers are exposed, the paintability is poor, and even if the resin sheet is glued, there will be no separation between the molded product and the molded product. This may cause bubbles to form or the resin sheet to peel off easily.

[0006]

[Means for Solving the Problems] The present invention has been made in view of the above-mentioned problems, and it is possible to prevent the passage of glass fibers to the surface layer of a molded body in which glass fibers are bonded with a synthetic resin binder. This is a glass fiber-reinforced synthetic resin molded product characterized by an air-permeable sheet having a gap of the same size as that is integrally fixed.

[0007]

[Operation] With the above structure, the glass fibers are prevented from being exposed to the surface by the air-permeable sheet on the surface layer, so the glass fibers do not irritate the skin even if the surface is touched. In addition, if the breathable sheet is integrally fixed to the surface layer of the molded body by penetration curing of a synthetic resin binder, the breathable sheet will be integrated without using adhesives, making manufacturing easier. It is firmly fixed.

[0008] Furthermore, by setting the voids in the air-permeable sheet to 1/10 to 1/2 of the length of the glass fibers, the synthetic resin binder can sufficiently penetrate into the voids, and exposure of the glass fibers can be reliably prevented. Furthermore, if a stretchable fabric or nonwoven fabric is used as the breathable sheet, even if the molded body is bent, the breathable sheet will expand and contract following the bending deformation of the synthetic resin, and no peeling will occur.

[0009]

[Embodiment] Fig. 1 shows an embodiment of the glass fiber reinforced synthetic resin molded article A of the present invention, in which glass fibers 1 are bonded with a synthetic resin binder 2 to form a plate-like molded body 3. On the surface layer of the molded body 3,
A breathable sheet 4 made of a net-like material is fixedly integrated with the synthetic resin binder 2 by curing.

The synthetic resin binder 2 is a thermoplastic resin or phenol resin such as polyethylene, polystyrene, acrylonitrile/styrene/butadiene, polypropylene, polyethylene terephthalate, polyvinyl chloride, polybutylene terephthalate, etc., and binds glass fibers together. There is. Among these resins, polypropylene, polyethylene, and the like, which are crystalline resins whose melt viscosity is extremely reduced by heating, are preferably used because glass fibers are appropriately dispersed therein and easily penetrate into the voids of the breathable sheet 4.

[0011] The glass fiber 1 has a length of, for example, 7 to 50 m.
m fibers are mixed in an amount of 20 to 60% by weight of the molded body, and the synthetic resin binder 2 is mixed in an amount of 40 to 80% by weight of the molded body 3 so as to substantially bind the glass fibers. It is mixed in the proportion of Although the glass fiber length may be 50 mm or more, the moldability will be poor, and
Since the flow of the synthetic resin binder 2 will be poor and the adhesion force to the breathable sheet 4 will also be reduced, the length is preferably 50 mm or less. In addition, if it is less than 7 mm, the reinforcing effect will be small,
Undesirable. And the diameter of glass fiber 1 is 5 to 20
μ, preferably 10 to 15 μ is used. Incidentally, stainless steel or copper metal fibers or carbon fibers can be used simultaneously with the glass fiber 1, and this material can be used as an electromagnetic wave shielding material.

The breathable sheet 4 is made of, for example, natural fibers such as cotton fibers and pulp, woven or nonwoven fabrics of synthetic resin fibers such as polyethylene fibers, polypropylene fibers, nylon fibers, and polyethylene terephthalate fibers, or synthetic resins made of the above resins. A net or a resin sheet with many fine through holes is used.

This breathable sheet 4 suppresses the glass fibers in the surface layer of the molded body 3 and embeds them inside the synthetic resin binder 2, and also prevents the glass fibers 1 from being exposed to the surface. The purpose of the present invention cannot be achieved if the openings are so small that 1 does not pass through the breathable sheet 4, and the purpose of the present invention cannot be achieved if the openings are so coarse that the glass fibers are exposed through the openings, such as the mesh of the breathable sheet 4.

[0014] Therefore, the void is 1 of the length of the glass fiber.
/10 to 1/2 is preferable, more preferably 1/3 to 1
/2 range. If the gap is 1/2 or more, the glass fibers will be exposed through the gap, and if the gap is 1/10 or less, the glass fibers will not be exposed, but the penetration of the synthetic resin binder 2 will be insufficient, and the fixing force will decrease. It is. If the glass fibers are 7 to 50 mm thick, they tend to spring back when the sheet 6 (described later) is heated, and are exposed to the surface of the molded body 3 through the molten resin binder 2, so there are gaps in the air permeable sheet 4. It is important to keep the value within the above range.

Next, a method for producing the glass fiber reinforced synthetic resin molded product A of the present invention will be explained. First, resin powder that will become the synthetic resin binder 2 and glass fiber are uniformly mixed in water or air, and heated and pressed with a roll or the like to melt the resin powder and form a sheet 6 bonded to the glass fiber. In order to perform molding using this sheet 6, as shown in FIG.
After placing the sheet 6, an appropriate number of preheated sheets 6 are placed in the recess, and then pressed using an upper mold member 7 having a convex portion.

In this way, the molten synthetic resin binder 2 in the sheet 6 flows into the voids in the breathable sheet 4, filling the voids and integrating them, and the glass fibers 1 cannot pass through the voids, preventing ventilation. As a result, the surface of the molded body 3 becomes smooth without the presence of glass fibers 1. During this pressing, the heated sheet 6 tends to expand due to the springback of the glass fibers, so if the gap between the molds 5 and 7 is made wider than the thickness of the sheet 6, the molded body 3 will become porous.

[0017] Hereinafter, the present invention will be explained in more detail using examples. Polypropylene resin powder, diameter 13μ, length approximately 13mm
Sheet 6 was prepared by mixing the following glass fibers. A polyethylene resin net with the mesh shown below was placed inside the lower mold material 5, and the heated sheet 6 was then placed at 200°C.
It was pressed at 30 kg/cm2. The results are shown in the table below.

[0018]

[Table 1] From this result, the mesh size of the breathable sheet is 3.2 mm, 1
．． It has been found that when the thickness is 6 mm, the polypropylene sufficiently penetrates into the mesh, and a good condition is created in which the glass fibers are not exposed. Also, if the mesh is 6.4mm,
It was also found that very little glass fiber was exposed.

The above-mentioned breathable sheet 4 may be provided on both sides of the molded body 3 or on the entire outer peripheral surface. Further, the shape of the molded product is not limited to a plate-shaped molded product, but may be formed into a curved molded product or a bent molded product. Such molded product A can be used for various panel materials such as concrete forms, vehicle interior materials,
It can be used as bag material, etc. When using it as a vehicle interior material, fabric etc. is integrally attached to the opposite side of the breathable sheet, and when using it as a bag material,
It is used by attaching cloth, etc. to the surface of the breathable sheet.

[0020]

[Effects of the Invention] As explained above, the present invention provides the following advantages:
Since it is a glass fiber reinforced synthetic resin molded product characterized by a breathable sheet having voids large enough to prevent the passage of glass fibers being integrally fixed by the synthetic resin binder, the air permeability of the surface layer is improved. Since the sheet prevents the glass fibers from being exposed to the surface, there is no risk of the glass fibers irritating the skin even if the surface is touched. In addition, by integrally fixing the breathable sheet to the surface layer of the molded body through penetration of the synthetic resin binder, the breathable sheet is integrated without using a separate adhesive, making it difficult for the sheet to peel off. .

Furthermore, since the glass fibers have a length of 7 to 50 mm and the breathable sheet has voids that are 1/10 to 1/2 of the length of the glass fibers, the synthetic resin binder fully enters the voids and provides strong adhesion. In addition, the glass fibers are not exposed on the surface of the molded product, making it easy to handle.

[Brief explanation of drawings]

FIG. 1 is a sectional view showing an example of a glass fiber reinforced synthetic resin molded product of the present invention.

FIG. 2 is a cross-sectional view illustrating the method for manufacturing a glass fiber-reinforced synthetic resin molded product of the present invention.

[Explanation of symbols]

1 Glass fiber 2 Synthetic resin binder 3. Breathable sheet

Claims (3)

[Claims] Claim 1: A breathable sheet having voids large enough to prevent passage of glass fibers is integrally fixed to the surface layer of a molded body made of glass fibers bound with a synthetic resin binder by the synthetic resin binder. Glass fiber reinforced synthetic resin molded product. 2. The glass fiber-reinforced synthetic resin molding according to claim 1, wherein the breathable sheet is integrally fixed to the surface layer of the molded body by penetration of a synthetic resin binder that binds the glass fibers. Goods. 3. The glass fiber has a length of 7 to 50 mm, and the air permeable sheet has voids of 1/10 to 1/2 of the length of the glass fiber. Glass fiber reinforced synthetic resin molded product as described.