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:
May. 02, 2000
Filed:
Sep. 22, 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 pellets of a sterically hindered phenol antioxidant such that the pellets have a balanced hardness so as to resist abrasion during conveyance yet being readily dispersed in a host plastic. Such novel pellets 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 1 gram of antioxidant dissolved therein per 100 grams of solvent and thereafter using the resulting solution of solvent and antioxidant to form a paste of additional portions of the antioxidant which is thereafter extruded, pelleted, and dried. The present invention further provides a novel process for controlling the hardness of a pelleted sterically hindered phenol antioxidant through the addition of from 0 to 80 weight percent of an alcohol of the formula ROH wherein R is an alkyl group of from 1 to 8 carbon atoms to the solvent system employed in the preparation of the processing aid and paste of antioxidant for further processing. The hardness of the resulting pellets is inverse to the amount of alcohol employed in the system.