| US 7,524,798 B2 | ||
| Use of a polyster composition as a hydraulic fluid | ||
| Markwart Kunz, Worms (Germany); Jörg Kowalczyk, Eisenberg/Steinborn (Germany); Alireza Haji Begli, Ramsen (Germany); Rainer Kohlstrung, Schwetzingen (Germany); Manfred Harperscheid, Römerberg (Germany); Angela Kesseler, Oberhausen (Germany); Rolf Luther, Speyer (Germany); Theo Mang, Weinheim (Germany); Christian Puhl, Grünstadt (Germany); and Helena Wagner, Cologne (Germany) | ||
| Assigned to Sudzucker Aktiengesellschaft Fuchs Petrolub AG, Manheim/Ochsenfurt (Germany) | ||
| Appl. No. 10/486,149 PCT Filed Jul. 22, 2002, PCT No. PCT/EP02/08140 § 371(c)(1), (2), (4) Date Feb. 06, 2004, PCT Pub. No. WO03/014269, PCT Pub. Date Feb. 20, 2003. |
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| Claims priority of application No. 101 38 686 (DE), filed on Aug. 07, 2001. | ||
| Prior Publication US 2005/0032653 A1, Feb. 10, 2005 | ||
| This patent is subject to a terminal disclaimer. | ||
| Int. Cl. C10M 169/04 (2006.01); C07C 53/00 (2006.01) | ||
| U.S. Cl. 508—220 [508/216; 554/227] | 23 Claims |
| 1. A method for making a base fluid for a rapidly biodegradable hydraulic fluid, said base fluid having low cold viscosity,
wherein the method comprises the steps of:
(a) forming a carbohydrate mixture comprised of mannitol and sorbitol; and
(b) esterifying said carbohydrate mixture with at least one selected from the group consisting of a C2 to C24 monocarboxylic acid, a C2 to C 24 monocarboxylic acid derivative and mixtures thereof to convert said carbohydrate mixture to a polyester mixture, such that
at least 75% of all free hydroxyl groups in the carbohydrate mixture are esterified, wherein the polyester mixture is said
base fluid.
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