Stabilisation of polyolefins and polyamides

摘要

Diphenylamine derivatives of the formula in which R represents a hydrogen atom or an alkyl or cycloalkyl group and A represents an acyl group derived from an aliphatic or cycloaliphatic acid containing at least 4 carbon atoms, are prepared by acylating the corresponding aminodiphenylamine with an appropriate acid chloride or acid anhydride. Specified instances of the radical R are methyl, ethyl, isopropyl, cyclohexyl and methylcyclohexyl groups and specified instances of the radical A are the residues of butyric, pivalic, valeric, lauric, myristic, stearic, oleic, adipic, succinic, sebacic, capric and cyclohexane carboxylic acids. The radical A may also be derived from a polycarboxylic acid and may contain chlorine atoms or cyano or alkoxy groups. In an example, 4-aminodiphenylamine is condensed with lauryol chloride in the presence of pyridine to yield 4-lauroylaminodiphenylamine. Other products similarly obtainable are 4-stearoylaminodiphenylamine, 4 - nonanoylaminodiphenylamine, 4- myristoylaminodiphenylamine, bis -(4 - diphenylamino) - adipamide and bis - (4 - diphenylamino) - sebacamide. The products are useful for protecting polyolefins and polyamides against oxidation (see Division C3).ALSO:As agents for protecting polyolefins and polyamides against oxidation, use is made of diphenylamine derivatives of the formula in which R represents an hydrogen atom or an alkyl or cycloalkyl group and A represents an acyl group derived from an aliphatic or cycloaliphatic acid containing at least 4 carbon atoms (see Division C2). 0.01-1% may be used. Specified instances of the radical R are methyl, ethyl, isopropyl, cyclohexyl and methylcyclohexyl groups and specified instances of the radical A are the residues of butyric, pivalic, valeric, lauric, myristic, stearic, oleic, adipic, succinic, sebacic, capric and cyclohexane carboxylic acids. The radical A may also be derived from a polycarboxylic acid and may contain chlorine atoms or cyano or alkoxy groups. Specified products are 4-lauroylaminodiphenylamine, 4 - stearoylaminodiphenylamine, 4-nonanoylaminodiphenylamine, 4 - myristoylaminodiphenylamine, bis - (4 - diphenylamino)-adipamide and bis - (4 - diphenylamino)-sebacamide. The action of the products on polyolefins may be enhanced by the conjoint use of sulphides, e.g. dilauryl thiodipropionoate, phosphite esters, e.g. tris-nonylphenyl phosphite, phenyl dioctyl phosphite or trilauryl trithiophosphite, dialkyldithiophosphates, e.g. zinc diisopropyldithiophosphate, dialkyl dithiocarbamates, e.g. zinc dinonyldithiocarbamate, or ultra-violet absorbing agents, e.g. 2-hydroxy - 4 - octyloxy - benzophenone. An example is given of the treatment of polypropylene, either alone or conjointly with dilauryl thiodipropionate. An example is given also in which a solution of polyhexamethylene adipamide in formic acid is treated and then converted into a film. The polymer in powder or chip form may also be mixed with the antioxidant before spinning.