Method for producing a carbon fiber bundle
AssigneeMitsubishi Rayon Co., Ltd.
InventorsNaoki SUGIURA, Akihiko Fukushima, Shinobu Fujie
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Abstract
A method to prepare a carbon fiber bundle which can develop satisfactory interfacial adhesion to polyolefin-based resins, especially polypropylene resins, is provided. The carbon fiber bundle comprises a plurality of single fibers 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 having an acid value of 23 to 120 mg KOH/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.
Claims2
A method for producing a carbon fiber bundle, comprising:
- pre-sizing the carbon fiber bundle with a pre-sizing agent consisting of an epoxy resin;
- treating the pre-sized carbon fiber bundle with an aqueous sizing agent solution to obtain a sized and presized carbon fiber bundle;
- cutting the obtained carbon fiber bundle to a prescribed length;
- and
- drying the carbon fiber bundle cut to the prescribed length,
- wherein
- the carbon fiber bundle comprises a plurality of single fibers,
- an amount of a sizing agent to the total weight is 1 to 5 wt %, and
- the aqueous sizing agent solution is obtained by dissolving or dispersing in water, a sizing agent comprising:
- a polymer having a main chain formed of carbon-carbon bonds, comprising an acid group in at least a part of side chains or at least a part of main chain ends, wherein an acid value of the polymer comprising acid groups is 23 to 120 mg KOH/g as measured in accordance with ASTM D1386;
- or
- a polymer having a main chain formed of carbon-carbon bonds, comprising at least one 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.
A method for producing a carbon fiber bundle comprising:
- treating the carbon fiber bundle with an aqueous sizing agent solution to obtain a sized carbon fiber bundle;
- cutting the sized carbon fiber bundle to a prescribed length with regulating the moisture content of the carbon fiber bundle to 20 to 60 wt %;
- and
- drying the carbon fiber bundle cut to a prescribed length
- wherein
- the carbon fiber bundle comprises a plurality of single fibers,
- the single fibers comprise a plurality of wrinkles on their surface,
- wherein
- a vertical difference between a highest portion and a lowest portion in a region defined by 2 μm of circumferential length×1 μm of fiber axial direction length of the single fibers is 40 nm or more,
- an amount of a sizing agent to the total weight is 1 to 5 wt %,
- the aqueous sizing agent solution is obtained by dissolving or dispersing in water the sizing agent comprising:
- a polymer having a main chain formed of carbon-carbon bonds, comprising an acid group in at least a part of side chains or at least a part of main chain ends, and an acid value of the polymer comprising acid groups is 23 to 120 mg KOH/g as measured in accordance with ASTM D1386;
- or
- a polymer having a main chain formed of carbon-carbon bonds, comprising at least one 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.
Dependencies are inferred from the claim text.