PROCESS FOR THE PREPARATION OF AN IMPROVED GELATIN FOR PHOTOGRAPHIC EMULSIONS AND GELATIN OBTAINED THEREOF.

摘要

P The manufacturing process of this gelatin comprising from 6000 to 8000 ppm of methionine, of which less than 20% is in oxidized form which consists a.) To demineralize the bones by action of an acid, b.) To treat l demineralized bone with a supersaturated aqueous solution of calcium hydroxide for several weeks, at a temperature between 10degree C and 25degree C, c.) to extract in hot water the gelatin from the ossein thus treated and neutralized , and d.) concentrating the gelatin broth obtained and then gelling and drying the gelatin, is characterized, according to the invention, in that the redox power of the treatment and extraction media is controlled. / P