Abstract: Elastomeric particles, which have a tendency to agglomerate, are rendered non-agglomerating by contacting those particles with an aqueous solution or dispersion of a polyurethane rubber, a high Mooney viscosity, high gel content rubber and/or a soap, and optionally a polar binder, separating the coated elastomeric particles from the solution or dispersion, and then drying the elastomeric particles while keeping the coated particles in motion.

Abstract: Nitrile rubber emulsion latexes containing anionic emulsifying aids such as surfactants are treated with large amounts of cationic polymeric coagulants to form innocuous water insoluble residues. The polymeric coagulants chemically react with the anionic emulsifying aids by forming polymer adducts whereby the adducts are physically maintained in the nitrile rubber. The need for complete or thorough washing steps, which is generally tedious, expensive, and commercially impractical, is thus reduced or eliminated. Moreover, the dried latex particles have been found to have improved properties such as water resistance, adhesion, and the like.

Abstract: There is disclosed a simple economical method of producing butadiene rubber, particularly NBR, in dry powder form free of extraneous material influencing its utility in rubber products manufacture. The method consists of preparing the butadiene rubber in latex form in the usual manner but using sodium lauryl sulfate or equivalent as emulsifier and then coagulating the latex with a combination of magnesium sulfate and aluminum sulfate, or their equivalents, in a molar ratio of Mg to Al in the range of 0.3 to 1 to 2 to 1. The coagulum wet cake obtained contains powder size particles of the rubber and is dried to give a dry free-flowing rubber powder, preferably after addition of zinc stearate or equivalent which functions as an anticake agent and prevents agglomeration of the powder size particles during drying. The zinc stearate can be added to the wet cake as dry powder or as a wet paste or produced in situ.

Abstract: A method for polymerizing olefinically unsaturated carboxylic acids containing at least one activated carbon to carbon olefinic double bond and at least one carboxyl group in an organic media in which said carboxylic acid is at least partially soluble, and a nonsolvent for the polymers of said carboxylic acid, in the presence of a free radical forming catalyst and a surface active agent having an HLB value in the range of less than 10.

Abstract: Handling problems of cadmium curing agents are minimized by adding to a nitrile rubber latex an antioxidant in the form of a soluble alkali metal salt to form a modified latex and then coagulating the modified latex with a cadmium salt to form nitrile rubber containing bound antioxidant in the form of a cadmium compound. Alternately, a concentrate containing a large proportion of the antioxidant in the form of a cadmium compound is prepared which can be subsequently added to a nitrile latex to provide the cadmate cure function.

Abstract: Particulate rubber is intimately and uniformly coated with an anti-cake(s) and pressed at mild temperatures to form friable rubber bales. The bales have a bulk density from about 1.3 to about two times that of the original particulate rubber and are capable of being handled as a slab and of supporting a direct load, yet break down under shear to form particles substantially similar in size and distribution to that of the original particulate rubber.