Process for producing modified molded article, molded article, diaphragm, and diaphragm valve
AssigneeDaikin Industries, Ltd.
InventorsHitoshi Imamura, Tatsuya Funaoka, Takeshi Shimono
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Abstract
The invention provides a process for producing a modified molded article capable of providing a diaphragm that is less likely to generate particles. The process for producing a modified molded article includes: molding modified polytetrafluoroethylene containing a tetrafluoroethylene unit and a modifying monomer unit based on a modifying monomer copolymerizable with tetrafluoroethylene to provide a molded article; and irradiating the molded article with not lower than 30 kGy but lower than 70 kGy of radiation at 270° C. to 310° C. to provide a modified molded article.
Claims14
A process for producing a modified molded article, comprising:
- molding modified polytetrafluoroethylene containing a tetrafluoroethylene unit and a modifying monomer unit based on a modifying monomer copolymerizable with tetrafluoroethylene to provide a molded article;
- and
- irradiating the molded article with not lower than 30 kGy but lower than 70 kGy of radiation at 270° C. to 310° C. to provide a modified molded article,
- wherein the modified polytetrafluoroethylene has non-processability and a standard specific gravity defined in ASTM D4895-89 of 2.13 to 2.23.
A molded article comprising modified polytetrafluoroethylene,
- the modified polytetrafluoroethylene containing a tetrafluoroethylene unit, modifying monomer unit based on a modifying monomer copolymerizable with tetrafluoroethylene,
- wherein the modified polytetrafluoroethylene constituting the molded article contains tertiary carbon, the tertiary carbon being present in an amount of 0.035 to 0.100 mol % relative to a sum of amounts of the tetrafluoroethylene unit and the modifying monomer unit, and
- wherein the modified polytetrafluoroethylene has non-melt-processability and a standard specific gravity defined in ASTM D4895-89 of 2.13 to 2.23.
A diaphragm obtainable by irradiating modified polytetrafluoroethylene with not lower than 30 kGy but lower than 70 kGy of radiation at 270° C. to 310° C.,
- wherein the modified polytetrafluoroethylene has non-melt-processability and a standard specific gravity defined in ASTM D4895-89 of 2.13 to 2.23.
Dependencies are inferred from the claim text.