A Study on Improvement in Durability of Chloroprene Rubber C.V. Joint Boot Seals

Chloroprene rubber (CR) compound has been mainly used as the material for constant velocity (C.V.) joint boot seals in Japan, but extension of the service life of CR boot seals is required. In order to meet this requirement, causes of breakage of CR boot seals have been analyzed in terms of the mechanism of deterioration of the rubber material with the elaps of time. As a result, it is found that the deterioration of the material is accelerated by oxygen and ozone molecules in the atmosphere, due to the reduced content of antideteriorant in the rubber material with the elapse of time.

Based on this finding, measures have been taken to insulate rubber surfaces from the atmosphere and to supply the antideteriorant to the rubber surface layer, which have extended the CR boot seal service life significantly.

This paper provides results of analysis on the mechanism and the effectiveness of those measures, based on the test results.