Solid anti-friction devices – materials therefor – lubricant or se – Lubricants or separants for moving solid surfaces and... – Heterocyclic ring compound; a heterocyclic ring is one...
Reexamination Certificate
2000-09-11
2004-08-03
Johnson, Jerry D. (Department: 1764)
Solid anti-friction devices, materials therefor, lubricant or se
Lubricants or separants for moving solid surfaces and...
Heterocyclic ring compound; a heterocyclic ring is one...
C508S292000, C508S293000
Reexamination Certificate
active
06770605
ABSTRACT:
FIELD OF THE INVENTION
Internal combustion engines operate under a wide range of temperatures including low temperature stop and go service as well as high temperature conditions produced by continuous high speed driving. Stop and go driving, particularly during cold, damp weather conditions, leads to formation of a sludge in the crankcase and in the oil passages of a gasoline or a diesel engine. This sludge seriously limits the ability of the crankcase oil to lubricate the engine effectively. In addition, the sludge with its entrapped water tends to contribute to rust formation in the engine. These problems tend to be aggravated by the manufacture's lubrication service recommendations which specify extended drain oils.
Another problem facing the lubricant manufacturer is that of seal deterioration in the engine. All internal combustion engines use elastomer seals, such as Viton™ seals, in their assembly. Over time, these seal are susceptible to serious deterioration caused by the lubricating oil composition and the deterioration results in oil leaking from the engine. A lubricating oil composition that degrades the elastomer seals in an engine is unacceptable to engine manufacturers and has limited value.
BACKGROUND OF THE INVENTION
It is known to employ nitrogen containing dispersants and/or detergents in the formulation of crankcase lubricating oil compositions. Many of the known dispersant/detergent compounds are based on the reaction of an alkenylsuccinic acid or anhydride with an amine or polyamine to produce an alkylsuccinimide or an alkenylsuccinamic acid as determined by selected conditions of reaction.
U.S. Pat. No. 4,558,170 (Chen et al., Dec. 10, 1985) is directed to polyisobutylene prepared from a mixed C
4
hydrocarbon feedstream using an AlCl
3
—HCl catalyst system wherein the HCl is introduced separately into the feedstream to form organochloride in the feedstream. Polymer product having a very narrow molecular weight distribution is obtained over the Mn range of 700 to 3,000. Dispersants derived from this polyisobutylene are said to exhibit substantially improved performance in lubricating oil compositions.
U.S. Pat. No. 5,614,480 (Salomon et al., Mar. 25, 1997) describes a lubricating oil composition which comprises a major amount of an oil of lubricating viscosity and
(A) at least about 1% by weight of at least one carboxylic derivative composition produced by reacting
(A-1) at least one substituted succinic acylating agent containing at least about 50 carbon atoms in the substituent with
(A-2) from about 0.5 equivalent up to about 2 moles, per equivalent of acylating agent (A-1), of at least one amine compound characterized by the presence within its structure of at least one HN< group; and
(B) at least one alkali metal overbased salt of a hydrocarbyl-substituted carboxylic acid or a mixture of a hydrocarbyl carboxylic acid and a hydrocarbyl-substituted sulfonic acid having a metal ratio of greater than 2 in an amount sufficient to provide at least about 0.002 equivalent of alkali metal per 100 grams of the lubricating oil composition wherein the hydrocarbyl substituent of the carboxylic acid contains at least about 50 carbon atoms.
U.S. Pat. No. 5,792,730 (Gutierrez et al., Aug. 11, 1998) is directed to the reaction product of hydrocarbons or polymers functionalized by halogenation (e.g. chlorination), thermal “ene” reaction or free radical grafting and derivatized with a heavy polyamine. A heavy polyamine is a mixture of polyalkylenepolyamines comprising small amounts of lower polyamine oligomers such as tetraethylene pentamine and pentahexamine but primarily oligomers with 7 or more nitrogens, 2 or more primary amines per molecule, and more extensive branching than conventional polyamine mixtures.
U.S. Pat. No. 5,936,041 (Diana et al., Aug. 10, 1999) pertains to improved lubricating oil dispersants wherein a fractionating polymer is prepared prior to functionalization (e.g. in the Koch reaction) for making dispersant additives. In one aspect, it was discovered that by fractionating a polymer to remove light hydrocarbon and unreacted monomer from the polymer before the carbonylation step of the Koch reaction, the amount of light ester impurities generated was minimized. Light ester is an undesirable byproduct that adversely affects the recycle of the catalyst from the functionalization step of the Koch reaction. The reference also pertains to improved lubricating oil nitrogen-containing dispersant additives derived from fractionated polymer.
SUMMARY OF THE INVENTION
The present invention provides a composition suitable for reducing engine sludge and degradation of elastomer seals comprising
a major amount of an oil of lubricating viscosity and
a minor amount of a nitrogen-containing dispersant wherein the nitrogen containing dispersant is a reaction product of
(I) a hydrocarbyl-substituted succinic acylating agent, wherein no more than about 20 mole percent of the individual molecules thereof have a hydrocarbyl substituent with a molecular weight of less than 500; wherein the hydrocarbyl substituent is a polymeric species consisting essentially of olefin monomer units of at least 3 carbon atoms; and
(II) at least one polyamine, wherein the polyamine is
(a) a polyalkylene amine containing at least one H—N< group; or
(b) a condensate of (i) a polyalkylene amine containing at least one H—N< group with (ii) at least one alcohol containing at least one ether group, amine group, nitro group, or additional alcohol group;
wherein in said polyamine (a) or condensed polyamine (b) no more than about 20 mole percent of the molecules contain 6 or fewer nitrogen atoms.
By means of an alternative description, the hydrocarbyl-substituted succinic acylating agent (I) is an agent wherein the hydrocarbyl substituent is prepared from a polymeric species consisting essentially of olefin monomer units of at least 3 carbon atoms and wherein no more than about 20 mole percent of the individual molecules of said polymeric species have a molecular weight of less than 500.
The invention also provides a method for reducing the formation of sludge and the degradation of seals in an engine, comprising lubricating the engine with the above-described composition.
REFERENCES:
patent: 4234435 (1980-11-01), Meinhardt et al.
patent: 4558170 (1985-12-01), Chen et al.
patent: 5053152 (1991-10-01), Steckel
patent: 5114435 (1992-05-01), Abramo et al.
patent: 5296560 (1994-03-01), Gutierrez et al.
patent: 5334321 (1994-08-01), Harrison et al.
patent: 5614480 (1997-03-01), Salomon et al.
patent: 5792730 (1998-08-01), Gutierrez et al.
patent: 5821205 (1998-10-01), Harrison et al.
patent: 5936041 (1999-08-01), Diana et al.
patent: 6066605 (2000-05-01), Emert et al.
patent: 370 805 (1990-05-01), None
patent: 451 380 (1991-10-01), None
Abraham William D.
Lamb Gordon D.
Raguz Mary Galic
Stachew Carl F.
Esposito Michael F.
Johnson Jerry D.
Shold David M.
The Lubrizol Corporation
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