GREEN STRENGTH PROMOTERS FOR EPDM/EPM COMPOSITIONS

摘要

EPM and/or EPDM compositions exhibiting superior green strength as compared to conventional EPM/EPDM compositions are attained by adding, along with the rubber curing agents and various conventional additives as desired, colemanite and/or alumina trihydrate. Colemanite, alumina trihydrate or a mixture of the two have unexpectedly been found to enhance the green strength of EPM/EPDM compositions prior to vulcanization. The green strength promoters of this invention utilized in EPM/EPDM rubber compositions allows for faster mixing (shorter mixing cycles) and improved processing rates, such as faster calender throughput rates, to be achieved. The green strength promoters can be utilized in generally any type of EPM and/or EPDM rubber formulation to improve the green strength thereof without adversely effecting the other desired physical properties. These green strength promoters are particularly useful in increasing the green strength of amorphous (non-crystalline) EPM/EPDM compositions.