CARBON FIBER BASE MATERIAL

PROBLEM TO BE SOLVED: To provide a carbon fiber base material, which suppresses a temperature dependence of a drape property under a normal temperature atmosphere and a low-temperature atmosphere and does not require different handling even under a work environment with temperature change.SOLUTION: A carbon fiber base material is made by disposing plenty of carbon fiber yarns to which sizing agent is applied are arranged in parallel. The carbon fiber base material has 1.2 or less of a ratio D2/D1, where D1 is the bending resistance of the carbon fiber base material under atmosphere at 20°C in an arranging direction of the carbon fiber yarns, and D2 is the bending resistance of the carbon fiber base material under atmosphere at 5°C in the arranging direction of the carbon fiber yarns.SELECTED DRAWING: Figure 1 【課題】常温雰囲気下と低温雰囲気下におけるドレープ性能の温度依存性を抑制し、温度変化を伴う作業環境でも取扱いの使い分けを必要としない炭素繊維基材を提供する。【解決手段】サイジング剤が付与された炭素繊維糸条が多数本並行に配列されてなる炭素繊維基材であって、炭素繊維糸条の配列方向における２０℃雰囲気下での炭素繊維基材の剛軟度Ｄ１と炭素繊維糸条の配列方向における５℃雰囲気下での炭素繊維基材の剛軟度Ｄ２との比Ｄ２／Ｄ１が１．２以下である炭素繊維基材。【選択図】図１