US 11,920,054 B1
Reactive extrusion of hydrophobically modified urethane thickeners and methods of manufacturing the same
Vito J. Pistone, Cleveland, OH (US); and Randolph B. Krafcik, Cleveland, OH (US)
Assigned to SWIMC LLC, Cleveland, OH (US)
Filed by SWIMC LLC, Cleveland, OH (US)
Filed on Apr. 20, 2020, as Appl. No. 15/929,264.
Claims priority of provisional application 62/837,230, filed on Apr. 23, 2019.
Int. Cl. C08G 18/48 (2006.01); C08G 18/24 (2006.01); C08G 18/28 (2006.01); C08G 18/75 (2006.01); C09D 175/08 (2006.01)
CPC C09D 175/08 (2013.01) [C08G 18/246 (2013.01); C08G 18/2825 (2013.01); C08G 18/4833 (2013.01); C08G 18/758 (2013.01); C08G 2150/00 (2013.01)] 6 Claims
 
1. A method of production of a hydrophobically modified, urethane thickener, wherein the thickener is produced by a reactive extrusion process, wherein the extrusion process comprises:
first, loading a polyether polyol feed comprising a polyethylene oxide into a twin-screw extruder, the extruder comprising a front end and a back end with an outlet at the back end, wherein the polyether polyol feed is loaded near the front end of the extruder, wherein the polyethylene oxide has a weight average molecular weight of 1,000 to 32,000,
second, loading an isocyanate functional material feed comprising a diisocyanate into the extruder at a point along the extruder closer to the back end of the extruder than where the polyether polyol feed was loaded, wherein the diisocyanate has the formula OCN—R—NCO where R is arylene, alkylarylene, alkylene, cyclic, or a hydrocarbon group containing ester or ether linkages, and
third, loading a hydrophobic modifier feed into the extruder at a point along the extruder closer to the back end of the extruder than where the polyether polyol and isocyanate functional material feeds were loaded, wherein the hydrophobic modifier feed comprises an aliphatic alcohol with 5 to 20 carbons;
wherein either the polyether polyol feed, the isocyanate functional material feed, or both further comprise a metal catalyst for catalyzing a reaction between the polyethylene oxide and the isocyanate functional material;
wherein the polyether polyol and isocyanate functional material feeds are placed close enough to the front of the extruder and the hydrophobic modifier feed is placed close enough to the back end of the extruder that when the combined polyether polyol and isocyanate functional material feeds reach the hydrophobic modifier feed in the extruder, the polyethylene oxide and diisocyanate have fully reacted;
wherein the hydrophobic modifier feed is located close enough to the front end of the extruder and far enough away from the extruder outlet to allow the combined polyether polyol feed, isocyanate functional material, and hydrophobic modifier feeds to react fully prior to reaching the extruder outlet, forming a hydrophobically modified urethane thickener and
wherein the extruder temperature is maintained at 80° C. to 140° C. from the front end to the back end of the extruder, and different temperatures may be maintained at different locations along the extruder from the front end to the back end; and
wherein the residence time for the extruder is one to five minutes.