U.S. patent application number 13/389711 was filed with the patent office on 2012-06-07 for grease composition and mechanical part.
Invention is credited to Masamichi Yamamoto.
Application Number | 20120142566 13/389711 |
Document ID | / |
Family ID | 43586203 |
Filed Date | 2012-06-07 |
United States Patent
Application |
20120142566 |
Kind Code |
A1 |
Yamamoto; Masamichi |
June 7, 2012 |
GREASE COMPOSITION AND MECHANICAL PART
Abstract
The invention provides a grease composition containing a base
oil, a thickener and an additive, characterized in that the base
oil has a kinetic viscosity at 40.degree. C. of 50 to 200
mm.sup.2/s; the thickener contains a diurea compound represented by
formula (I): R.sup.1--NHCONH--R.sup.2--NHCONH--R.sup.3 (wherein
R.sup.2 is a divalent aromatic hydrocarbon group having 6 to 15
carbon atoms, and R.sup.1 and R.sup.3, which may be the same or
different, represent cyclohexyl group or a straight-chain or
branched alkyl group having 8 to 22 carbon atoms); and the additive
is at least one selected from the group consisting of a metal salt
of naphthenic acid, a salt of a fatty acid having 6 to 10 carbon
atoms and an aliphatic amine having 6 to 10 carbon atoms, and a
metal salt of an organic sulfonic acid. The composition of the
invention shows excellent anti-fretting properties under the
conditions of ordinary temperature to low temperature (e.g.,
-50.degree. C., preferably about -40.degree. C.).
Inventors: |
Yamamoto; Masamichi;
(Fujisawa-shi, JP) |
Family ID: |
43586203 |
Appl. No.: |
13/389711 |
Filed: |
August 10, 2010 |
PCT Filed: |
August 10, 2010 |
PCT NO: |
PCT/JP2010/063521 |
371 Date: |
February 9, 2012 |
Current U.S.
Class: |
508/385 |
Current CPC
Class: |
C10N 2030/02 20130101;
C10N 2030/06 20130101; C10N 2040/02 20130101; C10M 2219/046
20130101; C10M 2207/126 20130101; C10M 2223/043 20130101; C10N
2010/04 20130101; C10N 2050/10 20130101; C10M 2205/0285 20130101;
C10M 2207/122 20130101; C10M 2215/04 20130101; C10M 2215/1026
20130101; C10N 2040/04 20130101; C10M 169/06 20130101; C10M
2223/045 20130101; C10M 2207/16 20130101; C10M 2203/1006 20130101;
C10N 2020/02 20130101; C10N 2040/32 20130101; C10M 2223/045
20130101; C10N 2010/04 20130101; C10M 2223/045 20130101; C10N
2010/04 20130101 |
Class at
Publication: |
508/385 |
International
Class: |
C10M 169/04 20060101
C10M169/04 |
Foreign Application Data
Date |
Code |
Application Number |
Aug 10, 2009 |
JP |
2009-185793 |
Claims
1. A grease composition comprising a base oil, a thickener and an
additive, wherein; the base oil has a kinetic viscosity at
40.degree. C. of 50 to 200 mm.sup.2/s; the thickener comprises a
diurea compound represented by formula (I):
R.sup.1--NHCONH--R.sup.2--NHCONH--R.sup.3 (I) (wherein R.sup.2 is a
divalent aromatic hydrocarbon group having 6 to 15 carbon atoms,
and R.sup.1 and R.sup.3, which may be the same or different,
represent cyclohexyl group or a straight-chain or branched alkyl
group having 8 to 22 carbon atoms); and the additive is at least
one selected from the group consisting of a metal salt of
naphthenic acid, a salt of a fatty acid having 6 to 10 carbon atoms
and an aliphatic amine having 6 to 10 carbon atoms, and a metal
salt of an organic sulfonic acid.
2. The grease composition of claim 1, wherein the metal salt of
naphthenic acid is at least one selected from the group consisting
of zinc cyclopentanoate and zinc cyclohexanoate; the amine salt is
a salt of a straight-chain fatty acid having 6 to 10 carbon atoms
and a straight-chain aliphatic amine having 6 to 10 carbon atoms;
and the metal salt of an organic sulfonic acid is at least one
selected from the group consisting of calcium
dinonylnaphthalenesulfonate, zinc dinonylnaphthalenesulfonate and
barium dinonylnaphthalenesulfonate.
3. The grease composition of claim 1, wherein the metal salt of
naphthenic acid is contained in an amount of 0.5 to 5.0 mass %, the
amine salt is contained in an amount of 1.5 to 5.0 mass %, and the
metal salt of an organic sulfonic acid is contained in an amount of
1.5 to 5.0 mass %, with respect to the total mass of the grease
composition.
4. A mechanical part in which the grease composition of claim 1 is
packed.
Description
TECHNICAL FIELD
[0001] The present invention relates to a grease composition and a
mechanical part. More particularly, the present invention relates
to a lubricating grease composition excellent in the anti-fretting
properties under the conditions from ordinary temperature to low
temperature, and a mechanical part, such as a bearing, containing
the grease composition therein.
BACKGROUND ART
[0002] Motorcars, electrical machines, and a variety of mechanical
parts and products are often transported by train or truck. During
the transportation, fretting may occur on the grease-applied
lubricating parts due to vibration induced by rail joints and rough
roads. The fretting is a surface damage induced under a minute
amplitude of vibration, and generates oxidized debris in the air,
which is said to often cause abrasive action to lead to
considerable abrasion (Yuji Yamamoto et al., "Tribology"
Rikogakusha Publishing Co., Ltd. (25 Nov. 1999): 201-203).
[0003] For prevention of the occurrence of fretting, there are some
proposals, for example, (1) to decrease the amplitude of the
relative sliding motion, (2) to separate both contact surfaces to
prevent direct contact, and (3) to prevent the adhesion of the
surfaces by coating the contact surfaces with a phosphate coating
or the like or supplying a lubricating oil or grease (Yuji Yamamoto
et al., "Tribology" Rikogakusha Publishing Co., Ltd. (25 Nov.
1999): 201-203).
[0004] In fact, many greases with excellent anti-fretting
properties have been developed and examined mostly in the technical
field of grease used in the wheel bearings of cars. For example, it
is reported that when compared with a grease where a lithium soap
is conventionally used as a thickener, a grease employing an
aromatic diurea as a thickener to increase the consistency exhibits
significantly improved anti-fretting properties (T. Endo:
Eurogrease, November/December (1997): 25-40).
[0005] Practically, the improvement in grease flowability has been
made to solve the problem of fretting, as mentioned above, by
changing the kinds of thickeners, increasing the consistency, and
the like.
[0006] However, the aromatic diurea has poor flowability.
Therefore, when the aromatic diurea is used for bearings, a short
lubricating life is exhibited in the angular contact ball bearings
due to insufficient flow of the grease into lubrication parts,
although a long life is exhibited in the deep-groove ball bearings.
The application of the aromatic diurea to bearings is thus limited.
As mentioned above, the improvement of grease by changing the
thickeners induces the problem that the resultant greases are
lacking in versatility.
[0007] In addition, the increase in grease consistency leads to the
problem of leakage, so that such greases cannot be used for the
parts sensitive to leakage. This also results in lack of
versatility.
[0008] Any of the above-mentioned measures are taken against the
fretting which may occur at ordinary temperature, and there is
almost no report that the fretting can be prevented under the
conditions of low temperature.
[0009] Under the conditions of low temperature, the flow of grease
is lowered as the viscosity of the base oil contained in the grease
increases, so that the ability to prevent the adhesion of the
surfaces by supplying a grease thereto as mentioned in the above
item (3) cannot be expected. As a measure to control the increase
in viscosity of the base oil at low temperature, it is proposed to
use a base oil mainly comprising expensive synthetic oils. However,
the above-mentioned measure has the drawbacks that the effect of
controlling the increase in viscosity of base oil is insufficient
and the raw material cost becomes high.
SUMMARY OF INVENTION
Technical Problem
[0010] An object of the invention is to provide a grease
composition excellent in anti-fretting properties.
[0011] Another object is to provide a grease composition capable of
exhibiting excellent anti-fretting properties under the conditions
from ordinary temperature to low temperature (for example, at
-50.degree. C., preferably about -40.degree. C.), without the use
of a base oil mainly comprising expensive synthetic oils.
[0012] A further object of the invention is to provide a mechanical
part where the above-mentioned grease composition is used.
Solution to Problem
[0013] The invention provides a grease composition and a mechanical
part as shown below.
[0014] (1) A grease composition comprising a base oil, a thickener
and an additive, wherein:
[0015] the base oil has a kinetic viscosity at 40.degree. C. of 50
to 200 mm.sup.2/s;
[0016] the thickener comprises a diurea compound represented by the
following formula (I):
R.sup.1--NHCONH--R.sup.2--NHCONH--R.sup.3 (I)
(wherein R.sup.2 is a divalent aromatic hydrocarbon group having 6
to 15 carbon atoms, and R.sup.1 and R.sup.3, which may be the same
or different, represent cyclohexyl group or a straight-chain or
branched alkyl group having 8 to 22 carbon atoms); and
[0017] the additive is at least one selected from the group
consisting of a naphthenic acid metallic salt, a salt of a fatty
acid having 6 to 10 carbon atoms and an aliphatic amine having 6 to
10 carbon atoms, and a metal salt of an organic sulfonic acid.
[0018] (2) The grease composition described in the above-mentioned
(1), wherein the naphthenic acid metallic salt is at least one
selected from the group consisting of zinc cyclopentanoate and zinc
cyclohexanoate; the amine salt is a salt of a straight-chain fatty
acid having 6 to 10 carbon atoms and a straight-chain aliphatic
amine having 6 to 10 carbon atoms; and the metal salt of an organic
sulfonic acid is at least one selected from the group consisting of
calcium dinonylnaphthalenesulfonate, zinc
dinonylnaphthalenesulfonate and barium
dinonylnaphthalenesulfonate.
[0019] (3) The grease composition described in the above-mentioned
(1) or (2), wherein the naphthenic acid metallic salt is contained
in an amount of 0.5 to 5.0 mass %, the amine salt is contained in
an amount of 1.5 to 5.0 mass %, and the metal salt of an organic
sulfonic acid is contained in an amount of 1.5 to 5.0 mass %.
[0020] (4) A mechanical part in which the grease composition
described in any one of the above-mentioned (1) to (3) is
packed.
Advantageous Effects of Invention
[0021] The grease composition of the invention has excellent
anti-fretting properties. Therefore, the grease composition of the
invention can be used for lubrication of various mechanical parts.
The targeted mechanical parts are not particularly limited, but
include rolling bearings, ball screws, linear motion guide
bearings, a variety of gears, cams and constant-velocity joints,
journal bearings (plain bearings), pistons, screws, ropes, chains
and the like. In particular, the grease composition of the
invention is suitable for the rolling bearings.
DESCRIPTION OF EMBODIMENTS
[0022] The base oil used in the grease composition of the invention
is not particularly limited so long as the base oil has a kinetic
viscosity at 40.degree. C. of 50 to 200 mm.sup.2/s. When the
kinetic viscosity at 40.degree. C. is less than 50 mm.sup.2/s, the
resultant grease film tends to be thinner and a sufficient
thickness of the grease film may not be ensured. When the kinetic
viscosity at 40.degree. C. exceeds 200 mm.sup.2/s, the viscosity
resistance is apt to increase.
[0023] From the viewpoints of cost and performance, mineral oils
are most preferable. The mineral oils or synthetic oils may be used
in combination when necessary.
[0024] As the synthetic oils, ester-based synthetic oils including
diester oils and polyol ester oils; synthetic hydrocarbon oils
including poly .alpha.-olefin and polybutene; ether-based oils
including alkyldiphenyl ethers and polypropylene glycols; silicone
oils; and the like can be used. Those base oils can be used alone
or in combination.
[0025] In consideration of the cost and performance, the content of
the mineral oil in the base oil may preferably be 70 mass % or
more, more preferably 80 to 100 mass %, and most preferably 100
mass %.
[0026] The thickener used in the grease composition of the
invention comprises a particular diurea compound represented by
general formula (I).
[0027] The diurea compound may be contained in the grease
composition of the invention in such an amount that the consistency
of the grease composition is preferably in the range of 235 to 325,
more preferably 280 to 325. To be more specific, the diurea
compound may preferably be contained in an amount of 5 to 15 mass
%, more preferably 8 to 12 mass %, based on the total mass of the
grease composition.
[0028] When the content of the diurea compound is less than 5 mass
%, the grease tends to soften and leak from the mechanical part
upon application of a shear force to the grease. The content of 15
mass % or more may lower the flowability of grease.
[0029] In contrast to this, it is impossible to impart sufficient
anti-fretting properties to the grease where a metallic soap such
as lithium soap is used as the thickener.
[0030] The additive used in the grease composition of the invention
comprises at least one selected from the group consisting of a
metal salt of naphthenic acid, a salt of a fatty acid having 6 to
10 carbon atoms and an aliphatic amine having 6 to 10 carbon atoms,
and a metal salt of an organic sulfonic acid.
[0031] Examples of metals for the metal salt of naphthenic acid
include zinc, magnesium, calcium, aluminum and the like. In
particular, zinc salts are most advantageous.
[0032] The fatty acid having 6 to 10 carbon atoms for constituting
the above-mentioned amine salt may be a straight-chain or branched
fatty acid.
[0033] The aliphatic amine having 6 to 10 carbon atoms for
constituting the above-mentioned amine salt may also be a
straight-chain or branched aliphatic amine. The amine salt from a
straight-chain fatty acid having 6 to 10 carbon atoms and a
straight-chain aliphatic amine having 6 to 10 carbon atoms is
preferred, and the amine salt from a straight-chain fatty acid
having 8 carbon atoms and a straight-chain aliphatic amine having 8
carbon atoms is further preferred.
[0034] Examples of the organic sulfonic acid for constituting the
above-mentioned metal salt of an organic sulfonic acid include
synthetic sulfonic acids such as petroleum sulfonate,
dinonylnaphthalenesulfonic acid, heavy alkylbenzenesulfonic acid
and the like, which are obtainable by sulfonating an aromatic
hydrocarbon component contained in the lubricating oil
fraction.
[0035] Examples of metals for the above-mentioned metal salt of an
organic sulfonic acid include calcium, zinc, barium, sodium and the
like. The calcium salt of an organic sulfonic acid may be a neutral
or highly basic salt. For example, calcium salts having a base
number of about 50 to 500 mgKOH/g can be used.
[0036] The metallic salts of dinonylnaphthalenesulfonic acid are
preferable, and in particular, calcium salts, zinc salts and barium
salts of dinonylnaphthalenesulfonic acid are preferred.
[0037] In the grease composition of the invention, the content of
the metal salt of naphthenic acid may preferably be 0.5 to 5.0 mass
%, and more preferably 1.0 to 5.0 mass %.
[0038] The content of the salt obtained from the fatty acid having
6 to 10 carbon atoms and the aliphatic amine having 6 to 10 carbon
atoms may preferably be 1.5 to 5.0 mass %, and more preferably 2.0
to 5.0 mass %.
[0039] The content of the metal salt of an organic sulfonic acid
may preferably be 1.5 to 5.0 mass %, and more preferably 2.0 to 5.0
mass %.
[0040] When two or more kinds of salts are used in combination, the
respective contents may appropriately be adjusted.
[0041] When the content is less than the above-mentioned lower
limit, the effect of preventing the fretting at ordinary
temperature or low temperature is unsatisfactory although there
appears a rust inhibitory effect. The content of more than 5.0 mass
% is considered to be uneconomical because more effect cannot be
recognized.
[0042] The metal salt of naphthenic acid, the fatty acid amine
salt, and the organic sulfonic acid salt used as the additives in
the grease composition of the invention are typical rust inhibitors
for lubricating oil, which are used in wide applications, also as
the rust inhibitors for the grease compositions.
[0043] However, there is neither report nor disclosure to the
effect that the above-mentioned metal salt of naphthenic acids, the
amine salts, and the metal salt of an organic sulfonic acids have
the effect on prevention of the fretting damage under the
conditions of ordinary temperature to low temperature.
[0044] When necessary, the grease composition of the invention may
further comprise other general-purpose additives in addition to the
above-mentioned metal salt of naphthenic acid, amine salt, and
metal salt of an organic sulfonic acid. For example, the following
additives can be used: [0045] Antioxidant
[0046] Amines: phenyl .alpha.-naphthylamine, alkylated phenyl
.alpha.-naphthylamine, alkylated diphenylamine and the like.
[0047] Phenols: hindered phenols such as
2,6-di-tert-butyl-p-cresol, pentaerythrityl tetrakis
[3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate],
octadecyl-3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate and the
like.
[0048] Quinolines: 2,2,4-trimethyl-1,2-dihydroquinoline polymer and
the like. [0049] Rust Preventive
[0050] Carboxylic acids and derivatives thereof; alkenylsuccinic
anhydride, alkenylsuccinate, half ester of alkenylsuccinate.
[0051] Carboxylates; metal (Ca, Ba, Mg, Al, Zn, Na or the like)
salts of fatty acids, dibasic acids, lanolin fatty acids,
alkenylsuccinic acids and the like, or amine salts thereof.
[0052] Passivators; sodium nitrite, sodium molybdate and the
like.
[0053] Esters; sorbitan trioleate, sorbitan monoleate and the
like.
[0054] Metal corrosion inhibitors; benzotriazole or derivatives
thereof, zinc oxide and the like. [0055] Extreme Pressure Agent
[0056] Phosphorus-containing compounds; tricresyl phosphate,
tri-2-ethylhexyl phosphate and the like
[0057] Sulfur-containing compounds; dibenzyl disulfide, a variety
of polysulfides and the like.
[0058] Sulfur-phosphorus containing compounds; triphenyl
phosphorothionate
[0059] Organic metal-based extreme pressure agents; Zn, Mo, Sb, Bi
salt or the like of dialkyl dithiophosphate, Zn, Mo, Sb, Ni, Cu, Bi
salt or the like of dialkyl dithiocarbamate, and the like.
[0060] Others, e.g., ashless dithiocarbamate, ashless
dithiophosphate carbamate and the like. [0061] Solid Lubricant:
Molybdenum Disulfide, Graphite, PTFE, MCA and the Like.
[0062] Under the conditions of ordinary temperature, it is possible
to prevent the fretting by changing the kinds of thickeners (the
effect as mentioned in the above-mentioned item (2) obtainable by
the aromatic urea coating), and increasing the consistency (i.e.,
improving the flow of grease), as shown in Comparative Examples 6
to 10, 19 and 20 to be described later.
[0063] At low temperature, however, flowability of the grease is
lowered, so that the effect of preventing the fretting by the
presence of grease cannot be expected.
[0064] The grease composition of the invention comprises a
particular additive (a metal salt of naphthenic acid, a salt of a
fatty acid having 6 to 10 carbon atoms and an aliphatic amine
having 6 to 10 carbon atoms, or a metal salt of an organic sulfonic
acid).
[0065] Therefore, for example, when the grease composition of the
invention is used for bearings, the strong adsorption of the
above-mentioned additive to the surface of members induces the
adhesive action at the interface between the diurea grease and the
balls and between the diurea grease and the inner/outer ring races.
Even under the conditions where the flow of grease is lowered, both
surfaces can be sufficiently separated to avoid the direct contact,
which is supposed to prevent the fretting at low temperature.
[0066] Those skilled in the art could not easily expect the effects
according to the invention of improving the anti-fretting
properties under the conditions from ordinary temperature to the
low temperature by the addition of the particular additive.
EXAMPLES 1 TO 14 AND COMPARATIVE EXAMPLES 1 TO 17
[0067] The predetermined amounts of raw materials isocyanate and
amine were allowed to react at a molar ratio of 1 to 2 in the base
oil. After a given amount of additives was added, the resultant
mixture was adjusted to have a predetermined consistency using a
three-roll mill.
Comparative Example 18
[0068] In a predetermined amount of base oil, lithium hydroxy
stearate was dissolved under application of heat with stirring.
After cooling the mixture, a given amount of additives was added,
and the resultant mixture was adjusted to have a predetermined
consistency using a three-roll mill.
<Test Methods>
[0069] Worked penetration: JIS K 2220.7 [0070] Fafnir friction
oxidation test (in accordance with ADTM D 4170) [0071]
Specification test for evaluating the anti-fretting properties
[0072] A test grease was applied to two sets of test thrust
bearings as shown below, and then the bearings were subjected to a
prescribed oscillation motion to determine the abrasion wear
(weight loss by the fretting wear).
[Test Conditions]
[0073] Bearing: ANDREWS W 5/8 Load: 2450 N (550 lbf) (contact
pressure: 1861 MPa) Angle of oscillation: 0.21 rad (12.degree.)
Oscillation cycle: 25 Hz Duration: 22 hours
Temperatures: 25.degree. C. and -30.degree. C.
[0074] Filling amount of grease: 1.0 g per bearing Abrasion wear:
weight loss of the race per bearing (by dividing the total weight
loss of the test bearing races by 2)
[Judgment]
[0075] oo: abrasion wear of 2.0 mg or less (anti-fretting
properties: excellent) o: abrasion wear of more than 2.0 mg and
less than 5.0 mg (anti-fretting properties: good) .DELTA.: abrasion
wear of more than 5.0 mg and less than 15.0 mg (anti-fretting
properties: slightly present) x: abrasion wear of 15.0 mg or more
(anti-fretting properties: absent) Test for determining corrosion
preventive properties: ASTM D1743-73 (test for determining
corrosion preventive properties for bearings)
[Judgment]
[0076] o: absence of corrosion x: presence of corrosion
[0077] The results are shown in Tables 1 to 5.
TABLE-US-00001 TABLE 1 Ex. 1 Ex. 2 Ex. 3 Ex. 4 Ex. 5 Ex. 6 Ex. 7
Isocyanate MDI*.sup.1 MDI*.sup.1 MDI*.sup.1 MDI*.sup.1 MDI*.sup.1
MDI*.sup.1 MDI*.sup.1 Amine ODA(1) ODA(1) ODA(1) ODA(1) ODA(1)
ODA(1) ODA(1) (molar ratio) CHA(7) CHA(7) CHA(7) CHA(7) CHA(7)
CHA(7) CHA(7) Thickener 11 11 11 11 11 11 11 (mass %) Base oil
(mixing Mineral Mineral Mineral Mineral Mineral Mineral Mineral
ratio by mass) oil (100) oil (100) oil (100) oil (100) oil (100)
oil (100) oil (100) Base oil (mass %) 88.3 88.0 87.0 87.0 87.0 87.0
87.0 Kinetic viscosity 100 100 100 100 100 100 100 of base oil
(40.degree. C.: mm.sup.2/s) Zinc 0.7 1.0 2.0 naphthenate*.sup.2
Fatty acid 2.0 amine salt*.sup.3 Ca sulfonate*.sup.4 2.0 Zn
sulfonate*.sup.5 2.0 Ba sulfonate*.sup.6 2.0 Worked 300 300 300 300
300 300 300 consistency Abrasion wear .smallcircle.
.smallcircle..smallcircle. .smallcircle..smallcircle.
.smallcircle..smallcircle. .smallcircle..smallcircle.
.smallcircle..smallcircle. .smallcircle..smallcircle. (25.degree.
C.) Abrasion wear .smallcircle. .smallcircle..smallcircle.
.smallcircle..smallcircle. .smallcircle..smallcircle.
.smallcircle..smallcircle. .smallcircle..smallcircle.
.smallcircle..smallcircle. (-30.degree. C.) Corrosion .smallcircle.
.smallcircle. .smallcircle. .smallcircle. .smallcircle.
.smallcircle. .smallcircle. preventive properties
TABLE-US-00002 TABLE 2 Ex. 8 Ex. 9 Ex. 10 Ex. 11 Ex.12 Ex. 13 Ex.
14 Isocyanate MDI*.sup.1 MDI*.sup.1 MDI*.sup.1 MDI*.sup.1
MDI*.sup.1 MDI*.sup.1 MDI*.sup.1 Amine OA OA OA OA OA OA OA (molar
ratio) Thickener 9 9 9 9 9 9 9 (mass %) Base oil (mixing Mineral
Mineral Mineral Mineral Mineral Mineral Mineral ratio by mass) oil
(100) oil (100) oil (100) oil (100) oil (100) oil (100) oil (100)
Base oil (mass %) 90.3 90.0 89.0 89.0 89.0 89.0 89.0 Kinetic
viscosity 100 100 100 100 100 100 100 of base oil (40.degree. C.:
mm.sup.2/s) Zinc 0.7 1.0 2.0 naphthenate*.sup.2 Fatty acid 2.0
amine salt*.sup.3 Ca sulfonate*.sup.4 2.0 Zn sulfonate*.sup.5 2.0
Ba sulfonate*.sup.6 2.0 Worked 300 300 300 300 300 300 300
consistency Abrasion .smallcircle. .smallcircle..smallcircle.
.smallcircle..smallcircle. .smallcircle..smallcircle.
.smallcircle..smallcircle. .smallcircle..smallcircle.
.smallcircle..smallcircle. wear (25.degree. C.) Abrasion
.smallcircle. .smallcircle..smallcircle. .smallcircle..smallcircle.
.smallcircle..smallcircle. .smallcircle..smallcircle.
.smallcircle..smallcircle. .smallcircle..smallcircle. wear
(-30.degree. C.) Corrosion .smallcircle. .smallcircle.
.smallcircle. .smallcircle. .smallcircle. .smallcircle.
.smallcircle. preventive properties
TABLE-US-00003 TABLE 3 Comp. Comp. Comp. Comp. Comp. Comp. Ex. 1
Ex. 2 Ex. 3 Ex. 4 Ex. 5 Ex. 6 Isocyanate MDI*.sup.1 MDI*.sup.1
MDI*.sup.1 MDI*.sup.1 MDI*.sup.1 MDI*.sup.1 Amine ODA(1) ODA(1)
ODA(1) ODA(1) ODA(1) ODA(1) (molar ratio) CHA(7) CHA(7) CHA(7)
CHA(7) CHA(7) CHA(7) Thickener 11 11 11 11 11 11 (mass %) Base oil
(mixing Mineral Mineral Mineral Mineral Mineral Mineral ratio by
mass) oil (100) oil (100) oil (100) oil (100) oil (100) oil (100)
Base oil (mass %) 89.0 87.0 87.0 87.0 87.0 87.0 Kinetic viscosity
100 100 100 100 100 100 of base oil (40.degree. C.: mm.sup.2/s)
Phosphoro- 2.0 thionate*.sup.7 Calcium 2.0 carbonate*.sup.8 Zinc
stearate*.sup.9 2.0 MoDTC*.sup.10 2.0 ZnDTP*.sup.11 2.0 Worked 300
300 300 300 300 300 consistency Abrasion wear x .smallcircle. x
.smallcircle. x x (25.degree. C.) Abrasion wear x x x x x x
(-30.degree. C.) Corrosion x x x x x x preventive properties
TABLE-US-00004 TABLE 4 Comp. Comp. Comp. Comp. Comp. Comp. Ex. 7
Ex. 8 Ex. 9 Ex. 10 Ex. 11 Ex. 12 Isocyanate MDI*.sup.1 MDI*.sup.1
MDI*.sup.1 MDI*.sup.1 MDI*.sup.1 MDI*.sup.1 Amine ODA(1) ODA(1)
ODA(1) OA OA OA (molar ratio) CHA(7) CHA(7) CHA(7) Thickener 11 8
11 9 9 9 (mass %) Base oil (mixing Mineral Mineral PAO (100)
Mineral Mineral Mineral ratio by mass) oil (100) oil (100) oil
(100) oil (100) oil (100) Base oil (mass %) 89 92 89 91 89 89
Kinetic viscosity 40 100 100 100 100 100 of base oil (40.degree.
C.: mm.sup.2/s) Phosphoro- 2.0 thionate*.sup.7 Calcium 2.0
carbonate*.sup.8 Worked 300 340 300 300 300 300 consistency
Abrasion wear .DELTA. .DELTA. x x .smallcircle. x (25.degree. C.)
Abrasion wear x x x x x x (-30.degree. C.) Corrosion x x x x x x
preventive properties
TABLE-US-00005 TABLE 5 Comp. Comp. Comp. Comp. Comp. Comp. Ex. 13
Ex. 14 Ex. 15 Ex. 16 Ex. 17 Ex. 18 Isocyanate MDI*.sup.1 MDI*.sup.1
MDI*.sup.1 MDI*.sup.1 MDI*.sup.1 Li soap Amine OA OA OA OA OA
(molar ratio) Thickener 9 9 9 9 7 8 (mass %) Base oil (mixing
Mineral Mineral Mineral Mineral Mineral Mineral ratio by mass) oil
(100) oil (100) oil (100) oil (100) oil (100) oil (100) Base oil
(mass %) 89 89 89 91 93 90 Kinetic viscosity 100 100 100 40 100 100
of base oil (40.degree. C.: mm.sup.2/s) Zinc 2.0 naphthenate*.sup.2
Zinc stearate*.sup.9 2.0 MoDTC*.sup.10 2.0 ZnDTP*.sup.11 2.0 Worked
300 300 300 300 340 300 consistency Abrasion wear .smallcircle. x x
.DELTA. .DELTA. x (25.degree. C.) Abrasion wear x x x x x x
(-30.degree. C.) Corrosion x x x x x .smallcircle. preventive
properties *.sup.1diphenylmethane diisocyanate *.sup.2metal salt of
naphthenic acid mainly comprising zinc cyclopentanoate *.sup.3salt
of a straight-chain fatty acid having eight carbon atoms and a
straight-chain aliphatic amine having eight carbon atoms
*.sup.4calcium dinonylnaphthalenesulfonate *.sup.5zinc
dinonylnaphthalenesulfonate *.sup.6barium
dinonylnaphthalenesulfonate *.sup.7mixture of alkylphosphoro
thionate compound and amine-based compound, HITEC 833 (trade name,
made by Afton Chemical Corporation) *.sup.8calcium carbonate
*.sup.9zinc stearate *.sup.10MOLYVAN A (trade name, made by R. T.
Vanderbilt Company, Inc.) *.sup.11LUBRIZOL 1395 (trade name, made
by The Lubrizol Corporation) ODA: octadecylamine CHA:
cyclohexylamine OA: octylamine PAO: poly-.alpha.-olefin
[0078] In the above tables, the added amount, i.e., mass % with
respect to the total mass of grease in parentheses of the items
marked with *2 to *6, *8 and *9 represent the concentration of
active ingredients in the additive.
[0079] In the above tables, the added amount, i.e., mass % with
respect to the total mass of grease in parentheses of the items
marked with *7, *10 and *11 represent the concentration of the
added commercially available product.
[0080] The grease compositions of Examples 1 to 14 where the metal
salt of naphthenic acid, salt of fatty acid having 6 to 10 carbon
atoms and aliphatic amine having 6 to 10 carbon atoms, or metal
salt of an organic sulfonic acid is added as the additive exhibit
minimum abrasion wear and excellent anti-fretting properties
without increasing the consistency under the conditions of ordinary
temperature and the low temperature; and excellent corrosion
preventive properties.
[0081] The grease compositions of Comparative Examples 1, 9 and 10
where no particular additive of the invention is contained show
considerable abrasion wear and poor anti-fretting properties under
the conditions of ordinary temperature and the low temperature; and
poor corrosion preventive properties.
[0082] The grease compositions of Comparative Examples 2, 4, 11 and
13 where any additives different from the particular additive of
the invention are contained show reduced abrasion wear at ordinary
temperature, but considerable abrasion wear and poor anti-fretting
properties at the low temperature, and inferior corrosion
preventive properties.
[0083] The grease compositions of Comparative Examples 3, 5, 6, 12,
14 and 15 where any additives different from the particular
additive of the invention are contained show considerable abrasion
wear and poor anti-fretting properties under the conditions of
ordinary temperature and the low temperature, and also poor
corrosion preventive properties.
[0084] The grease compositions of Comparative Examples 7 and 16
employing the base oils with a low kinetic viscosity show slight
abrasion wear at ordinary temperature, but considerable abrasion
wear and poor anti-fretting properties at the low temperature, and
also poor corrosion preventive properties.
[0085] The grease compositions of Comparative Examples 8 and 17
where the content of the thickener is decreased show a higher
worked consistency and slight abrasion wear at ordinary
temperature, but considerable abrasion wear and poor anti-fretting
properties at the low temperature, and also poor corrosion
preventive properties.
[0086] The grease composition of Comparative Example 18 employing
the lithium soap as the thickener show considerable abrasion wear
and poor anti-fretting properties at ordinary temperature and the
low temperature although satisfactory corrosion preventive
properties are found
* * * * *