Fiber-reinforced resin molding material and manufacturing method thereof

Abstract

The present invention relates to a fiber-reinforced resin molding material comprising at least discontinuous bundle-like aggregates of reinforcing fibers and a matrix resin, characterized in that the bundle-like aggregates of reinforcing fibers include the following two: reinforcing fiber aggregates A, It has a shape formed by cutting a bundle of continuous reinforcing fibers after performing a fiber splitting process for completely dividing the bundle into a plurality of bundles; and, a reinforcing fiber aggregate B1 or / and a reinforcing fiber aggregate B2 in which The body B1 has the shape of an uncut portion where the fiber splitting process is insufficient, and the reinforcing fiber aggregate B2 has a shape in which the fiber splitting process has not been performed, wherein the weight of the reinforcing fiber aggregate B1 is The ratio of the total weight of reinforcing fibers in the fiber-reinforced resin molding material, or the total weight of the reinforcing fiber aggregate B1 and the reinforcing fiber aggregate B2 relative to the total weight of reinforcing fibers in the fiber-reinforced resin molding material The weight ratios are all in the range of 50-95%. The present invention provides a fiber-reinforced resin molding material capable of achieving both good fluidity during molding and excellent mechanical properties of a molded product in a well-balanced manner, and a method for producing the same.

Description

technical field [0001] The present invention relates to a fiber-reinforced resin molding material and a method for producing the same, and more particularly to a fiber-reinforced resin molding material capable of achieving both good fluidity of the material when molded using the molding material and excellent mechanical properties of the molded product in a well-balanced manner and its manufacturing method. Background technique [0002] Using a fiber-reinforced resin molding material comprising discontinuous bundles of reinforcing fibers (for example, carbon fibers) (hereinafter, sometimes referred to as fiber bundles) and a matrix resin (for example, thermosetting resin), by heating and press molding, Techniques for molding into a molded body of a desired shape are known (for example, Patent Documents 1 to 5). In the conventional fiber-reinforced resin molding material as described above, when the fiber bundles in the fiber-reinforced resin molding material include fiber b...

AI Technical Summary

Problems solved by technology

In such a molding material, since the number of filaments in the fiber bundle is large, the reinforcing fibers can efficiently move together with the resin in the form of a fiber bundle during molding, so excellent fluidity can be obtained. For molded products after molding of molding materials, when the molded product breaks, there is a high possibility of stress concentration at the end of the fiber bundle in the molded product, so it is not suitable for molding molded products that require high mechanical properties.

[0004] On the other hand, for example, Patent Document 2 discloses a fiber-reinforced resin using a fiber bundle obtained by splitting so that the number of single filaments becomes 100 or less. Compared with fiber bundles, the number of monofilaments is small, so the reinforcing fibers are well dispersed in the molded product, the possibility of stress concentration at the end of the fiber bundle in the molded product is reduced, and the mechanical properties of the molded product are improved. But on the other hand, there is still a possibility that the desired level of high fluidity cannot be obtained during molding

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