METHOD FOR IMPROVING WATER REPELLENCY OF MOLDED ARTICLE OF POLYTETRAFLUOROETHYLENE

摘要

PURPOSE:To obtain a polytetrafluoroethylene molded article having a contact angle with water of a high value and excellent water repellency by heat-treating a molded article of a polytetrafluoroethylene. CONSTITUTION:A molded article of a polytetrafluoroethylene, preferably subjected to surface roughness by mechanical treatment, is heat-treated at a temperature (preferably 340-380 deg.C) of >= the melting point and < the decomposition temperature of the molded article of the polytetrafluoroethylene and preferably simultaneously brought into contact with a fluorine gas to improve water repellency of the molded article. The concentration of the fluorine gas is preferably 10-500 Torr and the contact time is preferably 10 minutes to one hour. The contact angle of the molded article of the polytetrafluoroethylene with water can reach 168 deg. at the highest value.