C - Chemistry – Metallurgy – 08 – L
Patent
C - Chemistry, Metallurgy
08
L
400/1113, 400/54
C08L 21/00 (2006.01) C08L 23/16 (2006.01)
Patent
CA 1315433
- 3 - the monoolefin rubber is largely non-crystalline, contains from about 0.1 to 10.0 weight percent, based on the monoolefin rubber, of pendent acid groups and is dispersed in the high-diene hydro- carbon rubber in particulate form with particles which have a weight average diameter below about 10 µm or are substantially all less than about 50 µm in diameter. In the blends of the invention, the particle size of the vulcanized monoolefin copolymer is particularly important and critical. It is necessary, first of all, that the vulcanized monoolefin copolymer portion be present as discrete particles, rather than continuous strands or sheets, forming large zones or globules of relatively undispersed rubber. Studies have shown that in blends of significant portions of EPDM rubber with high- diene hydrocarbon rubbers (such as natural rubber, polybutadiene or SBR rubber), the EPDM is dispersed well into the other rubber, in particles which are on the order of from less than one µm up to about 10 µm. (J.E. Callan, W.M. Hess and C.E. Scott, Rubber Chem. Technol. 44, 815 (1971)). The small, discrete particles, which are the disperse phase in the blends of the invention, permit the blends to exhibit the characteristic properties of the continuous phase, which is high-diene hydrocarbon rubber, yet retain some of the properties of the monoolefin copolymer rubber. The particles should have the size generally associated with the blends described in the art, that is, they should have a weight average diameter below about 10 µm, or in the alternative, they should substantially all be less than about 50 µm in dia- meter, which is the smallest size visible to the naked eye, and is also of sufficient size to act as a flaw in the cured rubber material and thus adversely affect its physical properties. In a preferred method, the blends of the invention can be made by mixing monoolefin copolymer rubber, a selective vulcanization agent therefor (said
526389
Coran Aubert Y.
Mcfadden Fincham
Monsanto Company
LandOfFree
Rubber blends does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Rubber blends, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Rubber blends will most certainly appreciate the feedback.
Profile ID: LFCA-PAI-O-1202181