PROBLEM TO BE SOLVED: To provide a medical catheter which exhibits a sufficient back flow preventing function, which is hardly split at the end part of a slit, and which does not keep the state in which a check valve is caught in when an obturator is extracted off.SOLUTION: In a check valve 10, a body part 12 so extends in a medical catheter 200 as to close toward a tip part of the medical catheter 200. Said body part 12 is formed with a slit 15 in a tapering tip part 14 which is connected with inclined side parts 13 inclined to have a mutual spacing tapered toward the tip, along a direction in which the tapering tip part 14 extends. A reinforcement rib 16 formed at one inclined side part 13 extends to the upper edge of the inclined side part 13 in a direction from a portion near one end of the slit 15 toward the central side of the slit 15 and in the direction apart from the slit 15. A reinforcement rib 16 formed at the other inclined side part 13 extends to the upper edge of the inclined side part 13 in a direction from a portion near the other end of the slit 15 toward the central side of the slit 15 and in the direction apart from the slit 15.COPYRIGHT: (C)2015,JPO&INPIT【課題】十分な逆流防止機能を発揮し、スリットの端部が裂け難く、オブチュレーターを抜き取る際に逆流防止弁が巻き込まれた状態に保持されない医療用カテーテルを提供する。【解決手段】逆流防止弁10は、医療用カテーテル200の内部を医療用カテーテル200の先端部に向かって閉じるように本体部12が延び、該本体部12は、先端に向かって互いの間隔が狭くなって先細るよう傾斜した傾斜側部13が繋がる先細り先端部14の延びる方向に沿って先細り先端部14にスリット15が形成され、一方の傾斜側部13に形成した補強リブ16がスリット15の一端寄りからスリット15の中央側に向かう方向で且つスリット15から離れる方向に傾斜側部13の上縁まで延び、もう一方の傾斜側部13に形成した補強リブ16がスリット15の他端寄りからスリット15の中央側に向かう方向で且つスリット15から離れる方向に傾斜側部13の上縁まで延びる。【選択図】図1
