JPH1044254A5 - - Google Patents

Description

[0016]
As described above, the multilayer structure shaped product of the present invention is a precursor for obtaining a final cured molded product. In the final cured molded product, it is desirable that the cured coating layer be sufficiently adhered to the core material. The adhesive strength is achieved by the adhesiveness of the resin component in the coating layer before curing, the pinholes and other fine irregularities on the surface of the cured core material, and the molding shrinkage of the coating layer. For the cured molded product, there is often no need to particularly improve the adhesive strength between the coating layer and the core material due to its intended use. However, if particularly improved adhesive strength is required, an adhesive can be used, or the surface of the core material can be roughened by an appropriate method such as sandblasting prior to placing the coating layer around the periphery of the core material. The present invention also includes cases where these appropriate methods are used.

[0018]
The epoxy resin can be prepared using the same knowledge as that used in the pultrusion molding method using epoxy resins. A typical example of the epoxy resin composition is 100 parts of Araldite AER 260 (manufactured by Ciba-Geigy), which is a bisphenol A diglycidyl ether, as the epoxy resin, 17 parts of 1,4-butanediol diglycidyl ether as a viscosity modifier, 4 parts of 2-methylimidazole as a curing agent, and a viscosity of 1600 centipoise at 25°C.

[0033]
Separately, glass roving 5 was passed through an impregnation tank 25 containing a thermosetting resin (B) 24 containing an isophthalic acid-based unsaturated polyester resin and an equal weight of aluminum hydroxide and coloring pigment to prepare impregnated glass roving 26. The impregnated roving 26 was placed around the outer periphery of the core material 2 coated with the epoxy resin 22, with a volume content of 50%, and then drawn into the second mold 20 via the positioning guide 7. A multilayer structure shaped product 4 was produced inside the mold near its entrance, with a cured core and an uncured coating layer around the periphery. The product was then drawn to the right in the figure and passed through the heating section of the second mold 20, covered with a hot plate 28, to obtain a multilayer molded product, a round bar 27. In the figure, reference numerals 18 and 28 denote hot plates for heating the curing molds 1 and 20, respectively. The molding speed was 40 cm/min. A round bar 27 made of a phenolic resin fiber-reinforced cured product with a beautifully pigmented surface was obtained.

Claims (4)

A multilayer structured object characterized by having a core made of a pultrusion-molded hardened material consisting of a fiber reinforcement material and a thermosetting resin (A), and having its outer periphery covered with a fiber reinforcement material impregnated with a thermosetting resin (B). A method for producing a multilayer structured object by a pultrusion molding method, characterized in that a pultrusion-molded hardened product obtained by passing a fiber reinforced material impregnated with a thermosetting resin (A) through a first mold is used as a core material, and a fiber reinforced material impregnated with a thermosetting resin (B) is arranged on the outer periphery as a coating layer, and then the core material is passed through a second mold or a concentrating tool. A method for producing a multilayer structure shaped object according to claim 2, characterized in that an epoxy resin is applied to the surface of a core material made of a pultrusion-molded hardened material obtained through a first mold, and a coating layer made of a fiber-reinforced material impregnated with a thermosetting resin (B) is placed on the outer periphery of the core material while the resin is in an unhardened or semi-hardened state. 4. The method for producing a multi-layer structured object according to claim 2 or 3, wherein the thermosetting resin (A) is a phenolic resin.