	US 12,466,985 B2
	Organophilic clays and drilling fluids containing them
Sarah Smith, Prince George, VA (US); Gary Davis, Westampton, NJ (US); Dennis Parrish, Sandston, VA (US); and Miyako Hisamoto, Glen Allen, VA (US)
Assigned to Evonik Corporation, Parsippany, NJ (US)
Filed by Evonik Corporation, Piscataway, NJ (US)
Filed on Dec. 28, 2022, as Appl. No. 18/090,343.
Application 18/090,343 is a division of application No. 17/087,621, filed on Nov. 3, 2020, granted, now 11,634,621.
Application 17/087,621 is a division of application No. 15/831,152, filed on Dec. 4, 2017, granted, now 10,865,338, issued on Dec. 15, 2020.
Claims priority of provisional application 62/430,486, filed on Dec. 6, 2016.
Prior Publication US 2023/0137391 A1, May 4, 2023
Int. Cl. C09K 8/36 (2006.01); C09K 8/03 (2006.01); C09K 8/32 (2006.01)

CPC C09K 8/36 (2013.01) [C09K 8/03 (2013.01); C09K 8/32 (2013.01)]

20 Claims

1. A method for preparing an organophilic clay, comprising:

a) mixing an aqueous suspension of a smectite-type clay with a quaternary ammonium salt comprising at least 75 mol-% bis-(2-hydroxypropyl)-dimethylammonium methylsulfate fatty acid ester, at a temperature above the melting point of the quaternary ammonium salt;

b) separating solids from the composition formed in step a); and

c) drying the solids separated in step b);

wherein the organophilic clay further comprises: (2-hydroxypropyl)-(1-methyl-2-hydroxyethyl)-dimethylammonium fatty acid esters, wherein the molar ratio of bis-(2-hydroxypropyl)-dimethylammonium fatty acid esters to (2-hydroxypropyl)-(1-methyl-2-hydroxyethyl)-dimethylammonium fatty acid esters is from 4:1 to 20:1.