GB1002643A - New organic peroxides - Google Patents

Abstract

A vulcanizable composition comprises a peroxide of the general formula <FORM:1002643/C3/1> in which R2 to R7 are alkyl groups containing from 1 to 6 carbon atoms, partially substituted or not with halogens, R1 is an alkyl group containing from 1 to 6 carbon atoms whose hydrogen atoms may be partially substituted with halogens or an aromatic group whose hydrogen atoms may be substituted or not with alkyl, aryl or cycloalkyl groups or with halogens, and A is an arylene group whose hydrogen atoms may be substituted or not as above, and a copolymer of ethylene and an alpha-olefin. Preferred copolymers contain ethylene in an amount of 5 to 70% by weight with propylene or butene-1. The concentration of peroxide is usually from 0.002 to 0.02 mols. per 100 g. of copolymer. Auxiliary substance such as sulphur, quinone compounds, vinyl monomers or dimaleimide may be present. The vulcanization may be carried out at from 110 DEG to 230 DEG C., preferably from 150 DEG to 200 DEG C. Auxiliary substances included in examples in addition to those specified above are carbon black, clay, silica, magnesium dioxide, diphenyl guanidine, diethylene glycol, liquid polybutadiene, divinylbenzene, p-quinonedioxime-dibenzoate.ALSO:The invention comprises a peroxide of the general formula <FORM:1002643/C2/1> in which R2 to R7 are aralkyl groups containing from 1 to 6 carbon atoms, partially substituted or not with halogens, R1 is an alkyl group containing from 1 to 6 carbon atoms whose hydrogen atoms may be partially substituted with halogens or an aromatic group containing from 6 to 20 carbon atoms whose hydrogen atoms may be substituted or not with alkyl, aryl or cycloalkyl groups or with halogens, and -A-is an arylene group whose hydrogen atoms may be substituted or not as above, particularly a ,a 1-bis(tert.-butylperoxy) - 1,4 - diisopropylbenzene; a ,a 1 - bis(cumyl peroxy) - diisopropylbenzene; di - tert. - butylperoxy - diisopropyldiphenyl; bis(tert.-butylperoxy) - 2,5 - diisopropyl naphthalene; and a mixture of meta and para a ,a 1- bis(tert. - butyl - peroxy) - diisopropyl - benzene. The novel peroxides are made by heating a mixture of an aromatic hydrocarbon having two mobile hydrogen atoms of the general formula <FORM:1002643/C2/2> and a catalyst consisting of a salt of copper, manganese or cobalt to 40 DEG C., or preferably 60-120 DEG C., with agitation and gradually adding an hydroperoxide of the general formula <FORM:1002643/C2/3> in an amount such as to provide a slight excess of hydroperoxide with respect to the hydrocarbon, and separating the diperoxide formed from the reaction mixture by evaporation under vacuum or by fractional crystallization. Alternatively, an alcohol of the general formula <FORM:1002643/C2/4> is reacted with the above hydroperoxide. The reaction is carried out in an alcohol, ketone or organic acid and an acid condensing agent, such as perchloric, sulphuric, or benzenesulphonic acid, or bromine trifluoride, is added to the solution or suspension while agitating at temperatures from room temperature to 120 DEG C. Examples describe the preparation of the above-mentioned specific peroxides and also a ,a 1-bis (cumyl peroxy)-diisopropyl-diphenyl.