GB300287A - Improvement in method of vulcanizing rubber - Google Patents

Abstract

300,287. Marks, E. C. R., (Rubber Service Laboratories Co.). May 9, 1927. Amines. - Rubber vulcanization accelerators are produced by treating the condensation products of aldehydes and amines known as Schiff's bases or the aldehyde derivatives of such bases with an acid, neutralizing the acid and then reacting the product with further aldehyde or with carbon disulphide. For example, ethylidene di-anilide. is prepared by adding 45 parts of acetaldehyde to 279 parts of aniline at a tempera.ture of preferably not more than 40‹ C., the mixture is cooled to not more than 30‹ C., and 5 parts bv weight. of 30 per cent hydrochloric acid are added. After standing the acid is neutralized by, preferably, calcium carbonate and the mixture is washed to remove the salt. The aldehyde reaction product is then obtained by adding 135 parts of acetaldehyde. In another example, an aldehyde derivative of a Schiff's base is prepared by adding 3 mols. of aldehyde to 2 mols. of a primary aromatic amine, the product is treated with dilute sulphuric acid, the acid is neutralized and formaldehyde added. The final product may be dried in vacuo. The accelerators may be prepared in the presence of a solvent such as free amine or benzol. Further specific examples of the preparation of accelerators are given. Specifications 7370/14, [Glass 70, Indiarubber &c.], 180,978, and 251,005 are referred to.