Ciba-geigy Corporation

Ambelal R Patel

Ramanathan Ravichandran

Raymond R Seltzer

Stephen D Pastor

Douglas Wayne Horsey

Frank P Cortolano

Charlene White

Peter W Stewart

James Peter Galbo

Richard W Thomas

Anthony DiBattista

An asymmetrical hydrazine derivative of formula V ##STR1## where R.sub.1 is alkoxy of 1 to 18 carbon atoms or cycloalkyl of 5 to 12 carbon atoms;

Azodicarboxylic acid derivatives containing hindered amine moieties as

New azodicarboxylic acid derivatives of formula I ##STR1## where R.sub.1 is hydrogen, oxyl, hydroxyl, alkyl, allyl, benzyl, alkoxy or acyl, and X is --O-- or --NR-- where R is hydrogen or alkyl, are useful for the stabilization of polymers, particularly unsaturated elastomers, by being grafted thereon.

The instant invention relates to novel hydrazine derivatives of formula III ##STR1## where R.sub.1 is hydrogen, oxyl, hydroxyl, alkyl, of 2 to 4 carbon atoms substituted by one hydroxyl group, allyl, benzyl, benzyl substituted by one of two alkyl of 1 to 4 carbon atoms or alkanoyl of 1 to 8 carbon atoms, and X is --O-- or --NR.sub.2 -- where R.sub.2 is hydrogen or alkyl. These compounds are useful as intermediates from which to prepare the corresponding azo compounds, which are useful for the stabilization of polymers, particularly unsaturated elastomers, by being grafted thereon.

Elastomers are very effectively stabilized against thermal and oxidative degradation at elevated temperatures with a blend of an N,N,N',N'-tetrasubstituted 1,4-diamino-2-butene, where the substituents are alkyl, cycloalkyl, aralkyl, aryl or mixtures thereof, in combination with a mercaptoimidazole of formula IV ##STR1## where E is hydrogen, alkyl, cycloalkyl, aryl or phenylalkyl.

N,N'-alkenylene amine/mercaptotolylimidazole blends as high temperature

Polyolefins, especially those containing a phenolic antioxidant, are prone to discoloration upon improper processing at elevated temperatures or upon prolonged aging. Such discolored polyolefins can be reclaimed and recycled as essentially non-colored useful polymers by the addition thereto of a hydroxylamine of the formula

Method for recycling discolored polyolefins

Hot melt adhesive compositions stabilized against thermal degradation, discoloration, skin formation and substantial viscosity changes, said adhesives being based on ethylene-vinyl acetate copolymer and a hydrocarbon tackifying resin and containing a stabilizer system of a hindered phenol antioxidant, a phosphite costabilizer and an acid scavenger.

Stabilized ethylene-vinyl acetate copolymer hot melt adhesive systems

Hindered amines based on various 2,2,6,6-tetraalkylated nitrogen-containing heterocyclic moieties wherein the hindered nitrogen atom on the ring is substituted with OR.sub.1 substituents and the 4-position of the ring is substituted with a diversity of substituents are effective in protecting polyolefins against the adverse effects of light, heat and oxygen.

Polyolefin compositions stabilized with NOR-substituted hindered amines

Hindered amines based on various 2,2,6,6-tetralkylated nitrogen-containing heterocyclic moieties wherein the hindered nitrogen atom on the ring is substituted with OH or OR substituents and the 4-position of the ring is substituted with a diversity of substituents are effective in protecting a variety of non-polyolefin substrates against the adverse effects of light, heat and oxygen.

Polymeric substrates stabilized with N-substituted hindered amines

Long chain N-alkyl-alpha-alkyl nitrones represent particularly valuable process stabilizers for polyolefin compositions. The nitrone derived from the long chain alkyl mixture present in di(hydrogenated tallow)amine is especially useful for this purpose.

Long chain N-alkyl-alpha-alkyl nitrones and polyolefin compositions

Long chain N,N-dialkylhydroxylamines represent particularly valuable process stabilizers for polyolefin compositions. The hydroxylamine derived from di(hydrogenated tallow)amine is particularly useful for this purpose. These long chain N,N-dialkylhydroxylamines are very resistant to extraction from polyolefin compositions.

Polyolefin compositions stabilized with long chain

Long chain N,N-dialkylhydroxylamines represent particularly valuable stabilizers for a number of polymer substrates. Their particular value is seen in their high temperature processing stabilization of poly(arylene sulfide), such as poly(phenylene sulfide), PPS, and of selected unsaturated elastomers used to modify thermoplastics. PPS is processed at elevated temperatures (300.degree. to 425.degree. C.) at which temperatures it crosslinks readily. Process stabilizers can extend the time to crosslinking and hence the processibility of the PPS. Long chain N,N-dialkylhydroxylamines are very effective process stabilizers for PPS being far superior to phenolic antioxidants, phosphites or amines. The hydroxylamine derived from di(hydrogenated tallow)amine is particularly useful for this purpose.

Long chain N,N,-dialkylhydroxylamines and stabilized compositions

N,N-Dibenzylhydroxylamine and other selected hydroxylamine derivatives are effective in stabilizing polyolefin compositions containing a stabilizer or mixture of stabilizers selected from the group consisting of the phenolic antioxidants, the hindered amine light stabilizers, the ultraviolet light absorbers, the organic phosphorus compounds, the alkaline metal salts of fatty acids and the thiosynergists, against degradation upon high temperature extrusion, exposure to the combustion products of natural gas, gamma irradiation or upon storage for extended periods.

Polyolefin compositions stabilized against degradation using

A stable phenolic antioxidant dispersion is prepared by adding, with high speed stirring, a melt of a phenolic antioxidant, which is an alkyl ester of a carboxylic acid containing an alkylhydroxyphenyl group, and a fatty acid to an aqueous solution of a base capable of forming a soap with said fatty acid. The dispersion may also be prepared by adding, with high speed stirring, a melt of the phenolic antioxidant to water, where either or both of the antioxidant and water contain an anionic or nonionic surfactant. These aqueous dispersions are useful in the stabilization of substrates which are better stabilized with water dispersible antioxidants against oxidative degradation induced by heat and/or light.

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Ardsley, NY, United States of America

Ambelal R Patel