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:
Nov. 15, 1994
Filed:
Aug. 20, 1993
Frank E Critchfield, South Charleston, WV (US);
Donald W Simroth, Charleston, WV (US);
Stuart L Watson, Midlothian, VA (US);
Arco Chemical Technology, L.P., Greenville, DE (US);
Abstract
The present invention provides polymer polyols and a method for preparing polymer polyols which have (1) exceptional dispersion stability, especially at high styrene contents, and (2) substantially smaller particle sizes than polymer polyols having equivalent viscosity. In a preferred embodiment of the present invention, a first reaction product is obtained by feeding the following materials to a first continuous reactor in the presence of a free radical initiator or catalyst: (a) less than about 50 wt % of a total monomer proportion or monomer mixture, preferably comprising styrene/acrylonitrile at a ratio preferably greater than about 50/50 wt %; (b) at least about 50 wt % of a total base polyol proportion; (c) a majority of a precursor stabilizer; and, (d) a polymer control agent (PCA). The product from this first reaction then is again fed through a continuous reactor, which may be the same as the first reactor, along with additional initiator, at least about 50% of the total monomer proportion, and, optionally, any balance of the total base polyol proportion, precursor stabilizer, and PCA. The product from this second reactor is a high stability, low viscosity polymer polyol.