| 摘要 |
PURPOSE:To obtain a contrast medium containing tube capable of effectively preventing discoloring of an X-ray contrast medium even when a fluorine resin is used for the tube by mixing the X-ray contrast medium and hexagonal boron nitride powder into the tube wall made of a thermoplastic resin. CONSTITUTION:The wall of a contrast medium containing tube is made of a thermoplastic resin with an X-ray contrast medium and hexagonal boron nitride powder mixed therein. In the contrast medium containing tube, hexagonal boron nitride as an additive is used because of its excellent lubricity with graphite type crystal form together with chemical stability. The boron nitride powder has the effect of improving fluidity of the molten resin and increasing the extrusion speed. As a result, stagnant time of the molten resin in extrusion machines is made shorter than heretofore to effectively prevent thermal decomposition of the resin. As a result, the X-ray contrast medium does not discolor even if a resin which produces reactive decomposition products of the fluorine resin is used for the tube. |
