The Preparation of Chlorinated Rubbers from Latex. Hypochlorination and Chlorination Processes

Abstract

Abstract With the view of extending the field of application of rubber latex, it has been considered desirable to study the behavior of this material toward various chemical reagents. Owing to the colloidal nature of latex the choice of reagent is considerably restricted; acids and many salts (especially those of bivalent and tervalent metals) produce coagulation, while alkaline reagents may cause creaming and aggregation of the particles. It is known that with the aid of certain stabilizers (e. g., saponin or casein) a stable acid latex may be obtained, but this is in general only stable over a limited range of pH values and is not stable to heat; moreover the stabilizer itself is prone to attack by the chemical reagent introduced. As would be anticipated from the foregoing considerations, the direct introduction of chlorine into latex immediately causes coagulation. Ellis and Boehmer (U. S. Patent 1,544,535) appear to have achieved some measure of success in chlorinating latex by using liquid chlorine under pressure, but the products obtained in different operations varied considerably in their properties.