Carbon fiber bundle, process for producing the same, and thermoplastic resin composition and molded article thereof

Abstract

A carbon fiber bundle is provided which can develop satisfactory interfacial adhesion to polyolefin-based resins, especially polypropylene resins. The carbon fiber bundle comprises a plurality of single fibers that was sized with a sizing agent comprising: a polymer having a main chain formed of carbon-carbon bonds, containing an acid group in at least part of side chains or at least a part of main chain ends, and representing an acid value of 23 to 120 mgKOH / g as measured in accordance with ASTM D1386; or a polymer having a main chain formed of carbon-carbon bonds and containing at least either of an epoxy group and an ester group in at least a part of side chains or at least a part of main chain ends.

Description

technical field [0001] The present invention relates to a carbon fiber bundle used as a reinforcing material for a thermoplastic resin and a method for producing the same. It also relates to a thermoplastic resin composition using these carbon fiber bundles and a molded article thereof. Background technique [0002] The so-called carbon fiber bundle is a carbon fiber bundle in which a plurality of single fibers made of carbon are gathered together and used as a reinforcing material such as a thermoplastic resin. [0003] When used as a reinforcing material of thermoplastic resin, carbon fiber bundles are generally supplied in a form cut into a length of 5 to 15 mm. When producing pellets kneaded with the carbon fiber bundles and the thermoplastic resin, it is necessary to supply the carbon fiber bundles to the extruder in a fixed amount, and thus the morphological stability of the carbon fiber bundles is important. If the shape is not suitable, it will cause spit spots. I...

AI Technical Summary

Problems solved by technology

[0009] However, for the method of adding an acid-modified polyolefin resin to the matrix resin, it is necessary to add a large amount of acid-modified polyolefin resin, which is not excellent in terms of reusability and economical efficiency.

In addition, for the method of sizing with a sizing agent containing a silane coupling agent, in the case of carbon fibers, compared with glass fibers, there are not as many hydroxyl groups present on the surface as glass fibers, so the effect of improving interface adhesion is equivalent. Low

[0010] In addition, in the method of sizing using a sizing agent containing acid-modified polypropylene as an essential component described in Patent Document 1, although relatively good interfacial adhesion with polyolefin resins can be achieved, carbon fiber case, the effect is not sufficient