Cleaning and liquid contact with solids – Processes – Metal base work – acid treating
Reexamination Certificate
2000-11-16
2003-04-08
Carrillo, Sharidan (Department: 1746)
Cleaning and liquid contact with solids
Processes
Metal base work, acid treating
C134S002000, C134S003000, C134S036000, C510S245000, C510S254000, C510S437000, C510S488000, C510S491000
Reexamination Certificate
active
06544349
ABSTRACT:
FIELD OF THE INVENTION
This invention relates to methods for cleaning internal parts of a machine and, more particularly, to methods for in situ cleaning of internal or inaccessible metal parts and rubber or silicone seals, using a synthetic ester of a naturally occurring fatty acid.
BACKGROUND OF THE INVENTION
Internal components of machines such as internal combustion engines, mechanical gearboxes, printing presses, compressors, hydraulic systems and the like often become contaminated during normal use when foreign matter or debris (lubricant degradation products such as carbon and varnish) is deposited on surfaces of parts and behind oil seals which often are not easily accessible for cleaning. These internal parts often mate or mesh with other parts of the machine or, in the case of seals, prevent oil or lubricant from leaking from the lubrication system, and are typically lubricated during operation. Lubricants, such as oil or grease, are sometimes capable of trapping loose debris that can be harmful to the machine, and it is common practice to periodically change the lubricant. Changing the lubricant, however, does not remove adhered debris or deposits from the metal parts of the machine or trapped behind oil seals. For example, in an internal combustion engine, changing the lubricant does not remove carbon deposits that adhere to pistons, rings, valves, cylinder heads and the like, and lead to deteriorization, decreased engine power and increased wear. In other machines, such as printing presses, accumulation of debris on rubber or silicone seals used to seal rotating or moving parts, or on moving metal parts that mate or mesh with each other, can adversely affect lubrication, performance and the useful life of the seals and other mechanical parts.
To remove adhered or accumulated debris that is not taken up and circulated in the conventional lubricating fluid used in the machine during operation, it is often necessary to disassemble the machine to clean the parts and/or replace the oil seals. Prior to introduction of strict environmental standards by the U.S. Environment Protection Agency (EPA) and similar agencies, it was common to clean metal components of various industrial machines using volatile organic compounds, such as hexane, benzene, toluene, methylethylketone and the like. It is time consuming to manually clean gears, chains, bearings other mechanical parts of machines. To avoid having to disassemble a machine to clean internal parts individually, it would be advantageous to provide effective and environmentally acceptable cleaning compositions for in situ cleaning of internal or otherwise inaccessible metal parts of a machine while the machine operates.
SUMMARY OF THE INVENTION
We have, surprisingly, found that synthetic esters of naturally occurring fatty acids provide effective cleaning compositions which, when added to the conventional lubricant in a machine having moving metal parts that are lubricated during operation, can clean those parts in situ, as well as remove debris that is lodged on or behind oil seals, while the machine is operating. The inventive method also has been found to reduce or inhibit oil leaks in such machines that can result from an accumulation of debris on or behind the oil seals of the machine. The method of the invention can increase the longevity and/or effectiveness of the oil seals. The cleaning compositions comprise a synthetic ester of a naturally occurring fatty acid, such as lanolin fatty acid, tall oil fatty acid, tallow fatty acid, coconut oil fatty acid or the like, wherein the alkyl moiety of the ester group is a straight or branched chain alkyl moiety having from about 6 to 20 carbon atoms. A presently preferred cleaning composition is provided by a synthetic ester prepared from the reaction of lanolin fatty acid and 2-ethylhexanol (i.e., an ester of lanolin fatty acid, wherein the ester group contains a 2-ethylhexyl moiety). The fatty acid esters described herein are environmentally desirable, yet possess very effective cleaning properties.
DETAILED DESCRIPTION OF THE INVENTION
In one of its aspects, the present invention entails a method for cleaning lubricated metal parts of a machine to remove debris adhered to the parts, comprising the step of operating the machine so that a circulating lubricant composition having a cleaning effective concentration of a synthetic ester of a naturally occurring fatty acid contacts the metal parts for an amount of time sufficient to clean adhered debris from the metal parts while the machine is operating.
In another of its aspects, the present invention entails a method for cleaning lubricated oil seals of a machine to remove debris accumulated at the oil seal, especially behind the oil seal, comprising the step of operating the machine so that a circulating lubricant composition having a cleaning effective concentration of a synthetic ester of a naturally occurring fatty acid contacts the oil seal and the debris accumulated at the oil seal for an amount of time sufficient to clean adhered or accumulated debris from the oil seal while the machine is operating. In this aspect of the invention, it has been found that oil seals made of rubber or silicone, when treated in the method of the present invention can have an increased effectiveness and longevity. Moreover, the method of the invention can inhibit or stop oil leaks occurring at the oil seals where the oil seal itself is not cracked or irreparably damaged.
The phrase “synthetic ester of a naturally occurring fatty acid” as used herein, means an ester that is formed such as in an esterification reaction between a naturally occurring fatty acid and an alcohol or other reactant capable of esterifying the fatty acid. The term “naturally occurring fatty acid” includes fatty acids that may be extracted from animal or plant material, or that may be chemically derived from their corresponding waxes, as is well known in the art. As used herein “naturally occurring fatty acid” includes lanolin fatty acid, coconut oil fatty acid, tall oil fatty acid, tallow fatty acid and the like, as well as saturated, monounsaturated and polyunsaturated fatty acids, such as myristic acid, palmitic acid, stearic acid, arachidic acid, myristoleic acid, palmitoleic acid, oleic acid, linoleic acid and the like, and mixtures of such fatty acids. Esters of lanolin fatty acid, coconut oil fatty acid, tall oil fatty acid and tallow fatty acid are presently preferred for use in accordance with the present invention. These and other fatty acids are commercially available. They may also be provided by saponification of their corresponding naturally occurring waxes, as is known in the art.
The phrase “debris accumulated on the parts” means lubrication degradation products which are adhered to or accumulated on parts of the machine such that the debris is not suspended or dissolved in conventional lubricating oil that circulates while the machine is operating, but is capable of being suspended or dissolved in lubricating oil supplemented with a cleaning effective concentration of a synthetic ester of a naturally occurring fatty acid, as described herein, while the machine is operating. The phrase “debris accumulated on the parts” includes lubricant degradation products such as carbon, varnish or brown carbon (as the term is used in the printing press field),that are adhered to the parts or are trapped in areas where the lubricant circulates, such as behind oil seals or the like.
The term “adhered debris,” or variation thereof, as used herein, refers to carbon deposits, varnish, and other foreign deposits that become bound to metal parts of a machine during normal operation in the presence of an oil or lubricant which lacks the synthetic fatty acid esters cleaning compositions described herein.
A “cleaning-effective concentration,” as used herein, means a concentration of a synthetic ester of a naturally occurring fatty acid that is capable of cleaning a detectable amount of debris from the metal parts or oil seals of a machine during operation for a predetermin
Donahue Donald R.
Miller Frank J.
Carrillo Sharidan
Feder Scott B.
Hastreier Roberta L.
Lord, Bissell & Brook
The Fanning Corporation
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