Ethyl Corporation

George L Mina

Raymond A Schell

Dixie E Goins

Lloyd E Goddard

Gary D Heidebrecht

John Borges

Glen L Livingston

John S Gramling

The 2-alkyl-6-t-butyl-4-(pentamethylbenzyl)phenols in which the 2-alkyl group is t-butyl or methyl are novel compounds having melting points sufficiently low to make them attractive as antioxidants for low melting polymers such as polyethylene, polypropylene, and polystyrene.

Phenolic antioxidants and stabilized organic compositions

3,5-dialkyl-4-hydroxybenzyl-substituted benzene compounds are made by reacting 2,6-dialkyl-4-methoxymethyl phenols with a benzene compound having an unsubstituted nuclear position in an inert solvent and in the presence of sulfuric acid catalyst while distilling methanol by-product from the reaction mixture as it forms.

Phenolic antioxidant process

3,5-dialkyl-4-hydroxybenzyl-substituted benzene compounds are made by reacting 2,6-dialkyl-4-methoxymethyl phenols with a benzene compound having an unsubstituted nuclear position in an inert solvent and in the presence of an organic sulfonic acid catalyst while distilling methanol by-product from the reaction mixture as it forms.

Antioxidant process

3,5-di-alkyl-4-hydroxybenzyl-substituted aromatics are made in improved yield by co-feeding 2,6-di-alkyl-4-alkoxymethyl phenol and sulfuric acid to a benzene compound, e.g. mesitylene, in an inert solvent at -10.degree. to 50.degree. C.

Process for making 3,5-dialkyl-4-hydroxybenzyl-substituted aromatics

Antioxidant compounds having the structure: ##STR1## in which p is 1 or 2 and + is a tert-butyl group provide excellent oxidation stability, melt flow index and yellow index, especially in polypropylene.

Antioxidant

Phenols, e.g. 2,6-di-tert-butylphenol, are coupled to form biphenols, e.g. 4,4'-bis(2,6-di-tert-butylphenol), by reaction with aqueous hydrogen peroxide under basic conditions in the presence of a phase transfer agent.

Biphenol process

A process for making a 2,6-di-hydrocarbyl-4-alkoxyalkylphenol, e.g. 2,6-di-tert-butyl-4-methoxymethylphenol, by reacting a 2,6-dihydrocarbylphenol with formaldehyde in a stoichiometric excess of alcohol and in the presence of a Mannich base catalyst preferably formed in situ by adding a catalyst-forming amount of a secondary amine, e.g. dimethylamine, to the mixture of 2,6-di-hydrocarbylphenol, formaldehyde and alcohol. Unreacted alcohol and amine are distilled out and the 2,6-di-hydrocarbyl-4-alkoxyalkylphenol is reacted with a benzene-type compound, e.g. mesitylene, to make a hindered phenolic antioxidant, e.g. 1,3,5-trimethyl-2,4,6-tri-(3,5-di-tert-butyl-4-hydroxybenzyl)benzene.

Antioxidant synthesis

Small amounts of paraformaldehyde and a carboxylic acid are added to a reaction mixture of trialkylbenzene and 3,5-dialkyl-4-hydroxybenzyl alcohol to thereby increase the yield of the product: trialkyl-tris(3,5-dialkyl-4-hydroxybenzyl)benzene. The reaction catalyst, sulfuric acid or a Friedel-Crafts catalyst, is not adversely affected by the additional ingredients.

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Orangeburg, SC, United States of America

George L Mina