JPH0110200Y2 - - Google Patents

Description

[Detailed explanation of the idea]

The present invention relates to an improvement in a continuous molded article made of fiber-reinforced thermosetting resin, which has a core made of a mixture of reinforcing fiber bundles and uncured thermosetting resin, and the periphery of the core is covered with a thermoplastic resin layer. The continuous molded product as described above is an intermediate product,
After storing the thermosetting resin in the core in an uncured state or transporting it to a predetermined location, it is immersed in boiling water or the like at a desired time to harden the thermosetting resin inside to obtain the final molded product. It is. However, the decomposition reaction of the catalyst also progresses during storage of such an intermediate continuous molded product, and this reaction is accelerated by the influence of temperature, accelerating the curing of the thermosetting resin in the core. As a result, the shelf life of this continuous molded product is shortened. In order to prevent the shelf life from being shortened in this way, it is possible to mix an antioxidant (polymerization inhibitor) into the uncured thermosetting resin.
If the amount of this antioxidant is large, the curing speed will be significantly reduced during curing to obtain the final molded product, and in extreme cases, curing will not occur. On the other hand, if the amount of this antioxidant is small, curing by ultraviolet rays will start again after it is consumed, so if the period for which the intermediate product is stored varies, the amount of this antioxidant mixed in should be adjusted. It was virtually impossible. Generally, carbon black is mixed as a coloring agent into the coating thermoplastic resin layer to improve weather resistance, but this carbon black reacts with the uncured thermosetting resin, causing the thermosetting resin to It has been found that it accelerates the curing of the resin and shortens the shelf life of the intermediate product. The present invention is based on the above-mentioned knowledge, and its purpose is to create a continuous molded product made of fiber-reinforced thermosetting resin that has excellent weather resistance and that prevents the curing of the internal thermosetting resin from being accelerated during storage of intermediate products. is to provide. Preferred embodiments of the present invention will be described below with reference to the accompanying drawings. In the figure, 1 is a core made of a mixture of reinforcing fiber bundles and uncured thermosetting resin, and most reinforcing fibers are glass fibers, carbon fibers, or aromatic polyamide fibers such as Kevlar (trademark). Common. Further, as the thermosetting resin, unsaturated polyester or epoxy resin is generally used. The outer periphery of the core 1 contains a first resin which does not contain any component that promotes curing of the thermosetting resin of the core 1.
A thermoplastic resin layer 2 is coated to constitute an intermediate layer. The most desirable resin for the first thermoplastic resin layer 2 is polyethylene resin or polypropylene resin, which does not contain an oxidation promoter such as a colorant, from the viewpoint of molding and economics. The outer periphery of the first thermoplastic resin layer 2 is further coated with a second thermoplastic resin layer 3 containing carbon black, preferably 1 to 4 wt%, to form a continuous fiber-reinforced thermosetting resin of the present invention. It composes things. Preferably, by mixing 0.1 wt% or more of an antioxidant into the first thermoplastic resin layer 2 forming the intermediate layer,
Phenol-based antioxidants are effective as this antioxidant. Next, a core made of a mixture of reinforcing fiber bundles and uncured thermosetting resin was coated with 2.6wt% carbon black.
The table below shows the test results comparing the weather resistance of the conventional product coated with a single layer of thermoplastic resin containing the present invention and the product of the present invention. In this test, the conventional product and the invented product were each stored indoors at a temperature of 30°C, where they were indirectly irradiated with ultraviolet rays from the sun, and the thermosetting resin in the core 1 was cured to a predetermined level. The shelf life before the product loses its flexibility was investigated.

【table】

[Table] As is clear from the above test results, the present invention has a core 1 made of a mixture of reinforcing fiber bundles and an uncured thermosetting resin, and a second thermoplastic resin layer containing carbon black ( The outer layer and the core are separated by interposing the first thermoplastic resin layer (intermediate layer) 2 which does not contain a component that promotes curing of the thermosetting resin in the core between the outer layer) 3 and the core. Since the carbon black in the outer layer does not react with the thermosetting resin in the core, the shelf life can be significantly extended compared to conventional products. Also,
By incorporating an antioxidant into the intermediate layer, the shelf life can be further extended significantly.

[Brief explanation of the drawing]

The figure is a partially sectional perspective view showing a continuous molded article made of fiber-reinforced thermosetting resin according to the present invention. 1... Core portion, 2... First thermoplastic resin layer (intermediate layer), 3... Second thermoplastic resin layer (outer layer).

Claims (1)

[Claims for Utility Model Registration] 1. A core made of a mixture of a reinforcing fiber bundle and an uncured thermosetting resin is surrounded by a first thermoplastic resin that does not contain a component that accelerates the curing of the thermosetting resin. 1. A continuous molded article made of fiber-reinforced thermosetting resin, characterized in that the thermoplastic resin layer is further covered with a second thermoplastic resin layer containing carbon black. 2. The continuous molded article made of fiber-reinforced thermosetting resin according to claim 1, wherein the first thermoplastic resin layer contains an antioxidant.