Improvement of the crosslinking of polychloroprene

The vulcanization of polychloroprene is usually performed by using metal ox ides and derivatives of thiourea, mainly ethylene thiourea (ETU), These vul canizates are known to have excellent physical properties, good aging resis tance and very good sealing properties that are based on the low compressio n and tension set. A substitution of ETU is necessary due to its assessment as Potential Carcinogen. Laws or regulations have already been issued in s everal European countries. 3-Methyl-thiazolidine-thione-2 (MTT) is an alter native crosslinking agent for polychloroprene, which permits an economical and ecological optimization of the processing. In the presence of MTT the a mount and the activity of zinc oxide and magnesium oxide also show signific ant influences on the crosslinking characteristics. This is another way in which the vulcanization rate can be influenced. The physical properties, e. g. tensile strength, depend only marginally on the vulcanization system. Fu rthermore, significant advantages in the compression set and the aging beha vior are found.