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:
Jan. 13, 2004
Filed:
Aug. 29, 2002
Thomas Rajewski, Auburn, MI (US);
John C. Tolfa, Midland, MI (US);
Hsinheng Li, Mt. Pleasant, MI (US);
The Lubrizol Corporation, Wickliffe, OH (US);
Abstract
A problem with refrigeration systems using ammonia as the refrigerant and hydrocarbon lubricants is that the seals/gaskets of the systems have a tendency to harden and shrink. This can cause leakage of the refrigerant and eventually require disassembly of the equipment and replacement of the seals. The addition of a small amount polyether having an aromatic fragment of 6-18 carbon atoms or an aliphatic fragment of 10-22 carbon atoms can soften the seals and partially re-swell the seals solving the leakage problem and avoiding expensive maintenance costs. Alternatively a polyether of 1,2-butylene oxide which is more oil soluble than most other polyethers with a smaller Z group e.g. derived from alkanols of 1 to 9 carbon would be effective at reducing hardening and shrinkage.