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
2001-09-27
2003-05-27
McAvoy, Ellen M. (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...
C508S373000, C508S376000, C508S391000, C508S469000, C508S502000, C508S586000
Reexamination Certificate
active
06569819
ABSTRACT:
BACKGROUD OF THE INVENTION
1. Field of the Invention
This invention relates to lubricant compositions, and more particularly to such a lubricant composition which is suitable as engine oils and highly effective in inhibiting sludge formation.
2. Description of the Prior Art
In gasoline engines, sludge is formed by the oxidative deterioration of the engine oil at elevated temperatures or the reaction between the engine oil and unburned fuel or blow-by gases (NOx) Such sludge clogs the oil passages and valves and increases the viscosity of the engine oil, leading to malfunctions of the engine. Therefore, engine oils have been demanded to have the ability to inhibit the formation of sludge as much as possible. Particularly due to the recent trend of high-powered engines and the decreased volume of oil pans for energy-saving, the engine oils have been used under severe conditions and thus been demanded to be highly effective in inhibiting sludge formation.
Generally, gasoline engine oils are produced by blending a lubricant base oil with additives such as ashless-dispersants, wear inhibitors, and metal-based detergents. In the conventional blend formulation, polybutenyl succinimides have been used as ashless dispersants.
However, known polybutenyl succinimides are too insufficient in terms of the sludge inhibiting effect to establish a technology of prolonging the life of engine oils.
In view of the foregoing, the object of the present invention is to provide a lubricant composition which has an excellent sludge inhibiting effect.
BRIEF SUMMARY OF THE INVENTION
According to the present invention, there is provided a lubricant composition which comprises a lubricant base oil and:
(A) a mono substituted amide type bissuccinimide in an amount of 0.5 to 20 percent by mass;
(B) zinc dithiophosphate in an amount of 0.05 to 0.3 percent by mass of phosphorus; and
(C) a metal-based detergent in an amount of 0.5 to 4.0 percent by mass of sulfated ash, based on the total mass of the composition.
A lubricant composition according to the present invention contains preferably (D) a dispersant-type viscosity index improver in an amount of 0.1 to 20 percent by mass based on the total mass of the composition.
DETAILED DESCRIPTION OF THE INVENTION
The present invention will be described in more details below.
Eligible lubricant base oils in the lubricant composition of the present invention are any mineral oils and/or synthetic oils which are used as base oil of conventional lubricants.
Specific examples of mineral oils which may be used include paraffinic- and naphthenic-mineral oils which are produced by subjecting lubricant fractions resulting from the atmospheric distillation and the vacuum distillation of crude oil to one or more refining processes such as solvent deasphalting, solvent extraction, hydrocracking, solvent dewaxing, catalytic dewaxing, hydrorefining, sulfuric acid washing, and clay treatment in suitable combination; and n-paraffinic mineral oils. In the case of using two or more of the refining processes, the processes can be combined in any suitable order or one particular refining process can be repeated a plurality of times under different conditions.
Although not restricted, examples of synthetic oils are one or more compounds selected from poly-&agr;-olefins such as 1-octene oligomer, 1-decene oligomer, and ethylene-propylene oligomer, and hydrides thereof, isobutene oligomers and hydrides thereof, isoparaffins, alkylbenzenes, alkylnaphthalenes, diesters such as ditridecyl glutarate, di-2-ethylhexyl adipate, diisodecyl adipate, ditridecyl adipate, and di-2-ethylhexyl sebacate, polyol esters such as trimethylolpropane caprylate, trimethylolpropane pelargonate, pentaerythritol-2-ethyl hexanoate, and pentaerythritol pelargonate, polyoxyalkylene glycol, dialkyldiphenyl ether, and polyphenyl ether.
Needless to mention, there may be used a mixture of the mineral oils and the synthetic oils mixed in any ratio, i.e., semi-synthetic oils as a base oil for the present invention.
No particular limitation is imposed on the viscosity of the lubricant base oils. However, the lower limit of kinematic viscosity at 100° C. is preferably 1.0 mm
2
/s, and more preferably 2.0 mm
2
/s, while the upper limit is preferably 10 mm
2
/s, and more preferably 8 mm
2
/s. The use of a lubricant base oils with a kinematic viscosity at 100° C. of 1.0 mm
2
/s or more makes it possible to produce a lubricant composition which can form oil film sufficiently and is more excellent in lubricity and more less in evaporation loss under elevated temperature conditions. The use of a lubricant base oil with a kinematic viscosity at 100° C. of 10 mm
2
/s or lower makes it possible to produce a lubricant composition which is reduced in fluid resistance, resulting in less friction resistance at sites to be lubricated.
Although not restricted, a lubricant base oil has a viscosity index of preferably 50 or more, and more preferably 80 or more. The use of a lubricant base oil with a viscosity index of 50 or more makes it possible to produce a lubricant composition having the abilities to both form oil film and reduce fluid resistance.
Although not restricted, a lubricant base oil has a pour point of preferably 0° C. or below, and more preferably −5° C. or below. The use of a lubricant base oil having a pour point of 0° C. or below makes it possible to produce a lubricant composition which does not hinder the engine work.
The lubricant composition of the present invention necessarily contains a lubricant base oil, (A) a mono substituted amide type bissuccinimide, (B) zinc dithiophosphate, and (C) a metal-based detergent.
Specific examples of (A) a mono substituted amide type bissuccinimide are compounds represented by formula (1) below and derivatives thereof:
In formula (1), R
1
, R
2
R
3
, and R
4
are each independently hydrogen, an alkyl or alkenyl group having 1 to 24 carbon atoms or an alkoxy group having 1 to 24 carbon atoms.
Specific examples of the alkyl or alkenyl group having 1 to 24 carbon atoms are straight-chain or branched alkyl groups such as methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, nonyl, decyl, undecyl, dodecyl, tridecyl, tetradecyl, pentadecyl, hexadecyl, heptadecyl, octadecyl, nonadecyl, eicosyl, heneicosyl, docosyl, tricosyl, and tetracosyl groups, and straight-chain or branched alkenyl groups such as butenyl, pentenyl, hexenyl, heptenyl, octenyl, nonenyl, decenyl, undecenyl, dodecenyl, tridecenyl, tetradecenyl, pentadecenyl, hexadecenyl, heptadecenyl, octadecenyl, nonadecenyl, eicosenyl, heneicosenyl, docosenyl, tricosenyl, and tetracosenyl groups.
Specific examples of the alkoxy group having 1 to 24 carbon atoms are alkoxy groups of which alkyl may be straight-chain or branched, such as methyloxy (methoxy), ethyloxy (ethoxy), propyloxy (propoxy), butyloxy (butoxy), pentyloxy, hexyloxy, heptyloxy, octyloxy, nonyloxy, decyloxy, undecyloxy, dodecyloxy, tridecyloxy, tetradecyloxy, pentadecyloxy, hexadecyloxy, heptadecyloxy, octadecyloxy, nonadecyloxy, eicosyloxy, heneicosyloxy, docosyloxy, tricosyloxy, and tetracosyloxy groups.
Preferred for R
1
, R
2
, R
3
, and R
4
are hydrogen, alkyl groups having 1 to 12 carbon atoms, and alkoxy groups having 1 to 12 carbon atoms with the objective of an excellent detergent effect.
In formula (1), R
5
and R
6
are each independently a straight-chain or branched alkyl or alkenyl group having 40 to 400 carbon atoms. Preferred for R
5
and R
6
are branched alkenyl groups derived from polypropylene, polybutene or polyisobutylene each having a number-average molecular weight of preferably 800 to 3500, and more preferably 900 to 2600, and hydrides of these alkenyl groups, i.e., branched alkyl groups. The terms “polybutene” and “polyisobutylene” designate those obtained by polymerizing a butene mixture or a highly purified isobuten using an aluminum chloride based catalyst or a boron fluoride based catalyst. No particular limitation is imposed on the method of producing them.
In formula (1), a and b are each independently an integer of 1 to 5.
Igarashi Jinichi
Kurosawa Osamu
Yagishita Kazuhiro
McAvoy Ellen M.
Nippon Mitsubishi Oil Corporation
LandOfFree
Lubricant compositions does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Lubricant compositions, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Lubricant compositions will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3038853