Ethyl Corporation

John C Wollensak

Kryn G Ihrman

Donald H Lucast

Chester P Jarema

Paul G Elsey

Ronald L Shubkin

Kju H Shin

Allen H Filbey

John D Bartleson

Luke J Governale

Dialkyl diamines for use with polyols and polyisocyanates in cast elastomer and reaction injection molding polyurethane processes. The dialkyl diamines are prepared by nitration and reduction of dialkylbenzenes or alkylation of meta-phenylenediamine. The chain extenders have the following structure: ##STR1## where R.sub.1 is C.sub.1 -C.sub.6 alkyl or C.sub.3 -C.sub.6 cycloalkyl and R.sub.2 is C.sub.2 -C.sub.6 alkyl or C.sub.3 -C.sub.6 cycloalkyl. Contrary to the teachings of the prior art the novel diamines have surprisingly good reaction times to form polyurethanes with excellent physical properties. Furthermore, little or no mold release is required in RIM and other processes using the chain extenders of the invention.

Polyurethanes from dialkyl diaminobenzenes and processes therefor

Methyl groups on N-methyl aromatic amines are redistributed to ring positions by heating in contact with an aluminum anilide catalyst and a nickel, cobalt, molybdenum or titanium-containing cocatalyst. For example, N-methyl-o-toluidine forms a mixture containing substantial quantities of 2,6-dimethylaniline, 2,4-dimethylaniline, and 2,4,6-trimethylaniline.

Process for rearrangement of alkyl groups on aromatic amines

Methyl groups on o-methyl aromatic amine are redistributed to ortho positions by heating in contact with an aluminum anilide catalyst and a nickel, cobalt, molybdenum or titanium-containing cocatalyst. For example, o-toluidine forms a mixture containing an aniline, o-toluidine, 2,6-dimethylaniline, and 2,4-dimethylaniline.

Polyurethanes can be produced using dihydroxyaromatic compounds as chain extenders. Preferred polyurethanes of this type are RIM (reaction injection molding) molded products or cast elastomers. The dihydroxyaromatic compounds are preferably selected from:

Phenol extended polyurethanes prepared by RIM process

Organic material such as lubricating oil is stabilized against oxidative degradation by addition of an alkyl aniline (e.g. 2,4,6-triethylaniline; 2-sec-butyl-6-ethylaniline), monoethyldiphenylamine and/or N-(2-amino-3-ethyl-.alpha.-methylbenzylidene)-2,6-diethylaniline or mixtures thereof.

Amine antioxidant

An improved 2,6-dialkylaniline process carried out by reacting an aromatic amine having an unsubstituted ortho position with an olefin in the presence of an aluminum anilide type catalyst followed by catalyst deactivation and distillation to remove 2,6-dialkylaniline. The distillation residue is catalytically hydrogenated and then distilled to recover additional 2,6-dialkylaniline.

Process for producing 2,6-dialkylanilines

Aromatic amines (e.g., aniline) are selectively alkylated in an ortho nuclear position by reaction with an olefin (e.g., ethylene) in the presence of an aluminum anilide catalyst. Hydrogen halides (e.g., HCl) are added to increase the reaction rate.

Chemical process

Ortho-cyclopentyl-hydroxybenzyl sulfides (e.g. di-(3,5-dicyclopentyl-4-hydroxybenzyl)sulfide) are effective antioxidants.

Thioether bis phenolic antioxidants

Methylenebis(dicyclopentyl phenols) in which at least one cyclopentyl group is ortho to the phenolic hydroxy group are effective antioxidants in a broad range of organic materials including mineral and synthetic lubricating oil and polyolefins.

Antioxidant

Hydroxy aromatics are aminated to form the corresponding aromatic amine by reaction at 200.degree.-400.degree.C with ammonia in the presence of a cyclohexanone and water in contact with a hydrogen transfer catalyst. For example, 2,6-dimethylphenol reacts with ammonia in the presence of cyclohexanone, water and a supported palladium catalyst to form 2,6-dimethylaniline.

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Bloomfield Hills, MI, United States of America

John C Wollensak