GB669548A - Improvements in or relating to the manufacture of a cork composition - Google Patents

Abstract

The process of the parent Specification in which moulded cork compositions are formed by mixing a synthetic rubber latex, e.g. of polymers of butadiene or chloroprene, or copolymers of butadiene with styrene or acrylonitrile, with cork particles of 5-50 mesh, coagulating the resultant mixture and subsequently moulding, is modified by effecting the coagulation of the latex without removal of water from the mixture. Coagulation is preferably effected by agitation for 2-10 minutes, and a part of the water may be removed after coagulation and before moulding. In examples, ground cork or reground composition cork of 10-30 mesh was added in a mixer to a composition containing latex, sulphur, zinc oxide, tetramethyl thiuram disulphide, methyl zimate, polymerized organic salts of alkyl aryl sulphonic acids, casein, ground bentonite, and ammonium hydroxide, and substances chosen from the sodium salt of the sulphate mono-esters of a mixture of higher fatty alcohols, di-alkyl esters of sodium sulpho-succinic acid, the sodium salt of a condensed aryl sulphonate, light mineral oil, clay filler, coumarone indene resins, asphalt, natural resins and hydrogenated methyl abietate, whereby the cork particles were coated with the binder and the latex was coagulated. A mat was formed from the composition by moulding whereby the binder was vulcanized.