Plasticizing rubber with a metal salt of an acylated aminothiophenol

摘要

Synthetic rubbers are plasticized with zinc salts of aminothiophenols (see Group IV (b)) of the formula:- where R is an alkyl or alkoxy radical of 1-4 carbon atoms, a phenylamino radical, an aryl radical of 6-12 carbon atoms or a heterocyclic radical. Synthetic rubbers specified are copolymers of butadiene-1 : 3 and styrene or acrylonitrile. In an example, a butadienestyrene (80 : 20) copolymer is milled at 100 DEG C. for 10 minutes with zinc o-carboisobutoxyamidothiophenate and the viscosity compared with an untreated sample and a sample treated with dibenzamidodiphenyldisulphide.ALSO:The invention comprises zinc salts of aminothiophenols of formula where R is an alkyl or alkoxy radical of 1-4 carbon atoms, a phenylamino radical, an aryl radical of 6-12 carbon atoms such as phenyl, tolyl, xylyl or naphthyl, or a heterocyclic radical such as furyl, thienyl, pyrrolidyl or pyridyl. The compounds are used as plasticizers for natural and synthetic rubbers (see Groups IV (a) and V) and are prepared by reacting the corresponding o,o1-disulphide with zinc dust and hydrochloric acid. The reaction is preferably carried out in an inert alcohol solvent such as methanol, ethanol or butanol. In examples: (1) o,o1-dibenzamidodiphenyldisulphide and zinc dust are slurried in methanol, hydrochloric acid is added and after refluxing for 1 1/2 hours the mixture is filtered and the filtrate is poured into water to precipitate zinc o-benzamidothiophenate; (2)-(6) using procedures similar to (1) and starting with the corresponding o,o1-disulphide the following are prepared: zinc o-phenylcarbamido-, o-acetamido -, o - (2 - furoylamido) -, o - carboethoxyamido - and o - carboisobutoxyamido - thiophenates.ALSO:Rubber is plasticized with a salt of an aminothiophenol (see Group IV(b)) of the formula: where R is an alkyl or alkoxy radical of 1-4 carbon atoms, a phenylamino radical, an aryl radical of 6-12 carbon atoms or a heterocyclic radical. Generally between 0,01 and 5 per cent of the zinc salt is used. In Examples samples of rubber are milled for 10 minutes at 212 DEG F. with the following zinc salts: zinc o-benzamido-o-carboethoxyamido-, o-acetamido-, o-(2-furoylamido)- and o-carboisobutoxyamido-thiophenates and the viscosities are compared with an untreated sample and one treated with dibenzamidodiphenyldisulphide.