Self-Vulcanizing Cements

Abstract By self-vulcanizing cements is to be understood cements, films of which at regular room temperature assume within a period of one or two days a vulcanized state. As implied by this definition, self-vulcanizing cements must be based on exceedingly active accelerators. The ultra-accelerators regularly used, such as thiuram disulfides, “Zimate,” and so forth, are not suitable for the purpose. We tested them in our preliminary work, and have proved their inadequacy in this respect. Nevertheless the industry used, under the name of self-vulcanizing cements, cements based on these accelerators. In self-vulcanizing cements accelerators with the lowest critical temperature must be used. Of those available, we chose Vulkacit P, Pipsol X, and zinc butylxanthate, and have established their critical temperature of vulcanization, with the following results: Critical temperature for tetramethylthiuram disulfide 110° C. Critical temperature for Vulkacit P 60° C. Critical temperature for Pipsol X (American) 60° C. Critical temperature for zinc butylxanthate 59° C. On the basis of the above results, we chose zinc butylxanthate. For an activator we used p-toluidine, the critical temperature of the accelerator being lowered from 50° C. to 40° C. by the p-toluidine. It was with this combination of zinc butylxanthate and p-toluidine that we carried out our next work on the following lines: 1. Development of a cement formula. 2. Testing the cement of the chosen formula under laboratory conditions by cementing leather specimens or canvas with rubber, and separating same after curing them in different conditions. 3. Study of gelling in the process of storing cements.