Hitachi Cable, Inc.

Nissan Motor Company Limited

Hitachi Metals, Ltd.

Hiroo Kusano

Yasuaki Yamamoto

Hideki Yagyu

Tomihito Hashimoto

Tomohito Ota

Hajime Nishi

Etsuo Fukuchi

Kazumasa Osono

Tomoyuki Nishio

A method of manufacturing a crosslinked fluororesin powder includes forming a powder mixture by mixing a fluororesin powder as a first powder with a second powder not fusing to the fluororesin powder even under conditions for crosslinking of the fluororesin powder, and conducting a cross-linking treatment to the formed powder mixture.

Method of manufacturing crosslinked fluororesin powder

A modified fluorocarbon resin composition and a modified molded product of fluorocarbon resin composition having an excellent abrasion resistivity and low friction property under high pressure, are provided. The modified fluorocarbon resin composition comprises a blend of fluorocarbon resin and aromatic engineering plastic, which is modified by irradiation of ionizing radiation.

Modified fluorocarbon resin composition and molded products

A seal ring () of the present invention seals operating oil hermetically and is attached to an annular seal ring groove () provided on an outer circumference of a shaft member (). The seal ring () includes fluororesin, modified fluororesin formed by being irradiated with an ionizing radiation in a range from 1 kGy to 10 MGy inclusive in a state of being heated up to a melting point thereof or higher under an inert gas atmosphere with an oxygen partial pressure of 1.33 kPa or less, and synthetic resin having a surface energy ranging from +0 N/cm to 20&#x2dc;10&#x2212;5 N/cm inclusive of that of the operating oil.

Seal ring and seal device

A seal ring seals operating oil hermetically and is attached to an annular seal ring groove provided on an outer circumference of a shaft member. The seal ring comprises fluororesin, metal powder having a hardness equal to or more than that of any of a side surface of the seal ring groove serving as a sliding partner and an inner circumferential surface of a housing engaged relatively rotatable with the outer circumference of the shaft member, and modified fluororesin formed by irradiating an ionizing radiation in a range from 1 kGy to 10 MGy inclusive in a state of being heated up to a melting point thereof or higher under an inert gas atmosphere with an oxygen partial pressure of 1.33 kPa or less.

A fluororesin heated at a temperature at or above the melting point of the resin is exposed in an inert gas atmosphere having an oxygen concentration of not more than 10 Torr to an ionizing radiation at a radiation dose of 0.1 kGy to 10 MGy to prepare a crosslinked fluororesin. The crosslinked fluororesin is exposed to an ionizing radiation at a radiation dose of 10 kGy to 5 MGy, and is then brought into contact with a functional group-containing organic compound to cause a graft reaction. By virtue of this constitution, a modified fluororesin is provided which has satisfactory mechanical strength and, at the same time, has, imparted thereto, for example, ion-exchange capacity, hydrophilicity, adhesive property, or abrasion resistance.

Modified fluororesin and process for producing the same

A fluoroplastic-based product having reduced friction and improved abrasion resistance having excellent abrasion resistance as well as good characteristics being inherent to fluoroplastics comprises a fluoroplastic molded material containing a modified fluoroplastic prepared by applying ionizing radiation to a fluoroplastic (I) heated at the melting point or a higher temperature under an inert gas atmosphere having 10 torr or less oxygen concentration within a range of irradiation doses of from 1 KGy to 10 MGy; and an unmodified fluoroplastic (II).

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Hitachi, Japan

Hiroo Kusano