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:
Sep. 22, 2015
Filed:
Feb. 03, 2012
Rainer Kolb, Kingwood, TX (US);
Phillip T. Matsunaga, Houston, TX (US);
Periagaram S. Ravishankar, Kingwood, TX (US);
Lisa B. Stefaniak, Houston, TX (US);
Quintin Paul Ward Costin, Baton Rouge, LA (US);
Rainer Kolb, Kingwood, TX (US);
Phillip T. Matsunaga, Houston, TX (US);
Periagaram S. Ravishankar, Kingwood, TX (US);
Lisa B. Stefaniak, Houston, TX (US);
Quintin Paul Ward Costin, Baton Rouge, LA (US);
ExxonMobil Chemical Patents Inc., Baytown, TX (US);
Abstract
Provided are processes for making polymer compositions, especially those with reduced or no gel formation in lubricating oils as identified by rheological and visual gel tests and which are useful as viscosity modifiers. The processes described herein aim to achieve this objective by adjusting the concentrations of the hydrogen feed(s) in the first and/or second polymerization reaction zones, preferably such that (a) the hydrogen feed concentration in the first polymerization reaction zone is 0.0-1.0 wt %, based on total weight of feed(s) of hydrogen, ethylene monomer, α-olefin comonomer, and solvent into the first polymerization reaction zone, and/or (b) the hydrogen feed concentration in the second polymerization reaction zone is 0.0-0.5 wt %, based on total weight of feed(s) of hydrogen, ethylene monomer, α-olefin comonomer, and solvent into the second polymerization reaction zone.