PRODUCTION METHOD OF POLYTETRAFLUOROETHYLENE MOLDED PRODUCT, PRODUCTION METHOD OF POLYTETRAFLUOROETHYLENE FILM, AND PRODUCTION METHOD OF LAMINATE

• Main Authors: KANAZAWA SHINICHI, SATO ATSUSHI, IKEDA KAZUAKI, SUGIHARA NAOKI
• Format: Patent
• Language: English; Japanese
• Published: 12.10.2022
• Subjects: AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F,C08G; CHEMISTRY; COMPOSITIONS BASED THEREON; GENERAL PROCESSES OF COMPOUNDING; LAYERED PRODUCTS; LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT ORNON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM; METALLURGY; ORGANIC MACROMOLECULAR COMPOUNDS; PERFORMING OPERATIONS; THEIR PREPARATION OR CHEMICAL WORKING-UP; TRANSPORTING; WORKING-UP

To provide a production method of a PTFE molded product with excellent abrasion resistance, in which the generation of cracks is suppressed in a production step.SOLUTION: A production method of a polytetrafluoroethylene molded product is a production method of a PTFE molded product having: (1) a first step to obtain a first molding by heating a molding material including PTFE with melt viscosity at 380°C of 7×105 Pa s or lower to a crystalline melting point of PTFE or higher; and (2) a second step to obtain a second molding after the first step by making the first molding be irradiated with ionizing radiation in a condition of no oxygen and at the crystalline melting point or higher, in which when conducting the second step after the first step, (a) after the first step, the second step is conducted while maintaining temperature of the first molding to be not lower than the crystalline melting point, or (b) after the first step, at least in a temperature range equal to or lower than the crystalline melting point and 300°C or higher, the first molding is cooled at a cooling rate of less than 2°C/minute, then the second step is conducted by heating the first molding to the crystalline melting point or higher.SELECTED DRAWING: Figure 1 【課題】 製造工程での割れの発生が抑制され、耐摩耗性が良好なＰＴＦＥ成形体を製造できる方法を提供する。【解決手段】 （１）３８０℃における溶融粘度が７×１０５Ｐａ・ｓ以下であるＰＴＦＥを含む成形材料をＰＴＦＥの結晶融点以上に加熱して第１成形物を得る第１工程と、（２）第１工程後、第１成形物に無酸素かつ上記結晶融点以上の条件下で電離性放射線を照射して第２成形物を得る第２工程とを有するＰＴＦＥ成形体の製造方法であって、第１工程の後、第２工程を行う際に、（ａ）第１工程の後、第１成形物の温度が結晶融点未満にならないように維持したまま第２工程を行うか、又は、（ｂ）第１工程の後、少なくとも上記結晶融点以下３００℃以上の温度域においては、第１成形物の温度を２℃／分未満の冷却速度で冷却し、その後上記結晶融点以上に加熱して第２工程を行う、ポリテトラフルオロエチレン成形体の製造方法。【選択図】図１