GB861940A - Improvements in the inhibition of volatile acid formation in preserved latex - Google Patents

Abstract

Volatile fatty acid formation in preserved, concentrated latex from Hevea brasiliensis during the period between the preserving and eventual use of the latex for making rubber articles is prevented by adding to the latex, before or immediately after concentration, a small proportion of an enzyme poison. The latex preserved is exemplified by ammoniated, centrifuged latex of 60% dry rubber content. The enzyme poison is exemplified by zinc oxide, copper chloride, silver nitrate, nickel chloride, sodium fluoride, semicarbazide hydrochloride, iodoacetic acid. Up to 2% of zinc oxide may be incorporated in the preserved latex. A longchain fatty acid, e.g. lauric acid, may be added to stabilize the latex. Antibiotics, e.g. 0.001-0.01% of a streptomycin, oxytetracycline, chlortetracycline and penicillin formulation, or other bactericides exemplified by 0.02-0.2% of sulphonamides such as sulphanilamide, sulphathiazolium, sulphaguanidine, phthalyl sulphathiazole and sulphamerazine, 0.1% of chlorinated phenols or xylenols or their sodium salts such as 6-chloro-o-cresol, pentachlorophenol, dichloro-m-xylenol, 0.05% of boric acid or its ammonium salt, and 0.01-0.2% of the vulcanization accelerators mercaptobenzthiazole, piperidine pentamethylene dithiocarbamate, aniline-formaldehyde condensate, cyclohexyl benzthiazyl sulphenamide, diphenyl guanidine, hexamethylene tetramine and selenium dimethyl dithiocarbamate, may be added. Specifications 800,089 and 821,872 are referred to.