The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Oct. 03, 2000
Filed:
Dec. 02, 1998
John Semen, Baton Rouge, LA (US);
Albemarle Corporation, Richmond, VA (US);
Abstract
The present invention is directed to a process for the production of agglomerates of a sterically hindered phenol antioxidant such that the agglomerates have a balanced hardness so as to resist abrasion during conveyance yet being readily dispersed in a host plastic. Such novel agglomerates are achieved through the use of a processing aid consisting of a solvent selected from the group consisting of methylene chloride, chloroform, toluene, acetone, methylethylketone, xylene, cyclohexane, styrene, methylcyclohexane and hexane having at least one gram of antioxidant dissolved therein per 100 mL of solvent and from about 20 to about 50 weight percent of an alcohol of the formula ROH wherein R is an alkyl group of 1 to 8 carbon atoms and thereafter using the resulting solution of solvent, alcohol, and antioxidant to form a paste of additional portions of the antioxidant which is thereafter agglomerated and dried. The present invention further provides a novel process for controlling the hardness of an agglomerated sterically hindered phenol antioxidant or a mixture of such antioxidant and a secondary phosphite antioxidant through the use of a processing aid wherein there is employed from 20 to about 50 weight percent of an alcohol of the formula ROH and wherein the hardness of the resulting agglomerate is inverse to the amount of alcohol employed in the system.