Fluorine-resin sealing ring

Abstract

A PTFE resin sealing ring in which at least one surface of an abutting part that forms a discontinuity in the sealing ring has been subjected to a plasma-modification treatment using a non-polymerizable gas and a pressure during plasma exposure of 10 to 500 Pa. Since the abutting surface(s) of this PTFE resin sealing ring has / have been subjected to a low-pressure plasma treatment, changing the states of the C-F bonds in the surface region(s), the abutting part does not stick even after a steady load has been applied at a high temperature, producing the prominent effect of ensuring both sealing performance under pressure and the ability to slide when not under pressure. This sealing ring is effective as a sealing material used with rotation or reciprocal motion, including a hydraulic circuit in a continuously variable transmission (CVT) or an automatic transmission (A / T) in an automobile, for example.

Description

technical field

[0001] The present invention relates to a fluororesin seal ring, and more particularly to a fluororesin seal ring capable of preventing fusion between fluororesin components. Background technique

[0002] Resin seal rings are now used in rotation or reciprocation in hydraulic circuits including, for example, automotive automatic transmissions (A / T), continuously variable transmissions (CVT), and the like. The resin seal ring generally has a joint portion constituting a discontinuity in a part of the ring in order to ensure mountability in the annular groove, sealability under pressure, and slidability under normal pressure, and is set so that A slight gap in the circumferential direction (joint gap) occurs at the joint when the seal ring is installed. When the temperature of the sealing fluid rises, the seal ring thermally expands, and the gap between the joints gradually narrows, resulting in a state where the cut surfaces of the joints butt against each ot...

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