Lubricating Oil Composition and Grease Composition Technical Field

Abstract
A lubricating oil composition, which comprises a perfluoropolyether base oil, and a fluorine-containing polyether diphosphonic acid ester, represented by the following general formula: (R2O)(R1O)P(O)(CH2)aCF(CF3) [OCF2CF(CF3)]bO(CF2)cO[CF(CF3)CF2O]dCF(CF3)(CH2)eP(O)(OR3)(OR4) (where R1, R2, R3, and R4 are hydrogen atoms, alkyl groups, cycloalkyl groups, aryl groups, alkylaryl groups, aralkyl groups, or any of the foregoing groups can be halogen atom-substituted groups, subscripts a, b, c, d, and e are in conditions of 2≦a+e≦8, b+d≦28, and 1≦c≦10, and b and d can be 0), and a grease composition which further contains a thickening agent in addition to the lubricating oil composition, have distinguished abrasion resistance and rust preventiveness without deteriorating the heat resistance inherent in the lubricating oil and the grease containing a perfluoropolyether oil as a base oil.
Description
TECHNICAL FIELD

The present invention relates to a lubricating oil composition and a grease composition, and more particularly to a lubricating oil composition and a grease composition with improved abrasion resistance, rust preventiveness, etc. to mating members by adding a fluorine-containing organophosphorus compound thereto.


BACKGROUND ART

The fluorine-containing organophosphorus compound has a good effect on the improvement of solvent resistance, chemical resistance, mold releasability, friction -abrasion resistance, etc. and thus has been so far used as various kinds of additives, a mold releasing agent, etc. So far well known fluorine-containing organophosphorus compounds includes, for example, phosphoric acid ester series or phosphonic acid ester series having linear perfluoroalkyl groups, and their utilization as a base oil for lubricating oil or grease has been limited, because they have a poor compatibility with perfluoropolyether oil, trifluorochloroethylene polymer oil, etc.


Phosphonic acid ester series having perfluoropolyether groups and having one terminal group consisting of phosphonic acid ester RfRPO(OR′)2 has been so far proposed. The phosphonic acid ester series are soluble in fluorine-containing base oil and have a good lubricability, but fail to fully satisfy recently imposed more stringent requirements for lubricability or rust preventiveness.


Patent Literature 1: JP-A-2003-27079


Phosphoric acid ester series having perfluoropolyether groups, or aryl phosphate, or phosphonate series, etc. having a mono- or poly-alkylene oxide bond group or not between the phosphorus and the fluorocarbon group have been also proposed. However, these compounds are liable to undergo hydrolysis, because the fluorine-containing group and the phosphoric acid group form a C—O—P bond, and thus have poor heat resistance and durability, failing to show a heat resistance, which is a characteristic inherent in fluoro series lubricating oil or grease.


Patent Literature 2: JP-A-6-136379


Patent Literature 3: JP-A-2002-510697


DISCLOSURE OF THE INVENTION
PROBLEM TO BE SOLVED BY THE INVENTION

An object of the present invention is to provide a lubricating oil composition and a grease composition with distinguished abrasion resistance and rust preventiveness without impairing the heat resistance inherent in lubricating oil and grease based on perfluoropolyether oil as a base oil, by adding a fluorine-containing organophosphorus compound to perfluoropolyether base oil.


MEANS FOR SOLVING THE PROBLEM

The object of the present invention can be attained by a lubricating oil composition, which comprises a perfluoropolyether base oil, and a fluorine-containing polyether diphosphonic acid ester, represented by the following general formula:

(R2O) (R1O)P(O)(CH2)aCF(CF3)
[OCF2CF(CF3)]bO(CF2)cO[CF(CF3)CF2O]d
CF(CF3)(CH2)eP(O)(OR3)(OR4)

(where R1, R2, R3, and R4 are hydrogen atoms, alkyl groups, cycloalkyl groups, aryl groups, alkylaryl groups, aralkyl groups or any of the foregoing groups, some or whole of whose hydrogen atoms are substituted with halogen atoms, and subscripts a, b, c, d, and e are integers satisfying conditions of 2≦a+e≦8, b+d≦28, and 1≦c≦10, and subscripts b and d can be 0), or by a grease composition, which comprises the lubricating oil composition and further a thickening agent.


EFFECT OF THE INVENTION

A lubricating oil composition, which comprises a perfluoropolyether base oil, and a fluorine-containing polyether diphosphonic acid ester as a new compound, and a grease composition, which comprises the lubricating oil composition and further a thickening agent, can show distinguished abrasion resistance and rust preventiveness without impairing the heat resistance inherent in both of the lubricating oil and the grease based on perfluoropolyether oil as a base oil.


BEST MODES FOR CARRYING OUT THE INVENTION

The fluorine-containing polyether diphosphonic acid ester compound represented by the foregoing general formula can be obtained by reaction of a fluorine-containing polyether dialkyl halide, represented by the following general formula:

X(CH2)aCF(CF3)[OCF2CF(CF3)]bO(CF2)c
O[CF(CF3)CF2O]dCF(CF3)(CH2)eX

    • X: Cl, Br, or I


      with one kind or two kinds of phosphonic acid or phosphonic acid ester (phosphite compound), preferably trialkyl phosphite, represented by the following general formulae:

      [A] (R1O)(R2O)P(OR)
      [B] (R3O)(R4O)P(OR)
    • R: hydrogen atom or a lower alkyl group
    • R1, R2, R3, and R4: as defined above


      In the case using only one kind of the same phosphite compound [A] or [B], a diphosphonic acid ester compound with same kind of both terminal groups can be obtained, whereas in the case of using two kinds of mutually different phosphite compounds [A] and [B], a diphosphonic acid ester compound with two different kinds of terminal groups can be obtained.


The fluorine-containing polyether diphosphonic acid ester compound so synthesized includes, for example, the following compounds, where for the alkyl groups, cycloalkyl groups, alkylaryl groups, and aralkyl groups of R1, R2, R3, and R4, usually alkyl groups having 1 to 10 carbon atoms can be used. Why the condition of 2≦a+e≦8 is set forth is due to easiness of synthesis, and why the conditions of b+d≦28 and 1≦c≦10, preferably 2≦c≦10 are set forth are due to easy availability of raw materials for synthesis.


(C2H5O)2P(O)(CH2)2CF(CF3)OCF2CF(CF3) O(CF2)2OCF(CF3)CF2OCF(CF3) (CH2)2P(O)(OC2H5)2


(C3H7O)2P(O)(CH2)aCF(CF3)[OCF2CF(CF3)]bO(CF2)4O[CF(CF3)CF2O]dCF(CF3)(CH2)eP(O)(OC3H7)2
2≦a+e≦6 and 2≦b+d≦6


(C3F7O)2P(O)(CH2)2CF(CF3)[OCF2CF(CF3)]bO(CF2)6O[CF(CF3)CF2O]dCF(CF3)(CH2)2P(O)(OC3H7)2
10≦b+d≦16


(C3H7O)(HO)P(O)(CH2)aCF(CF3) [OCF2CF(CF3)]bO(CF2)4O[CF(CF3)CF2O]dCF(CF3)(CH2)eP(O)(OH)(OC3H7)

2≦a+e≦6 and 2≦b+d≦6


(HO)2P(O)(CH2)aCF(CF3)[OCF2CF(CF3)]bO(CF2)4O[CF(CF3)CF2O]dCF(CF3)(CH2)eP(O)(OH)2
2≦a+e≦6 and 2≦b+d≦6


(C6H11O)2P(O)(CH2)2CF(CF3)OCF2CF(CF3)O(CF2)2OCF(CF3)CF2OCF (CF3)(CH2)2P(O)(OC6H11)2


(C6H11O)2P(O)(CH2)2CF(CF3)OCF2CF(CF3)O(CF2)2OCF(CF3)CF2OCF (CF3)(CH2)2P(O)(OC6H4CH3)2


(CH3C6H4O)2P(O)(CH2)2CF(CF3)OCF2CF(CF3)O(CF2)2OCF(CF3)CF2OCF (CF3)(CH2)2P(O)(OC6H4CH3)2


(C6H5O)2P(O)(CH2)2CF(CF3)[OCF2CF(CF3)]2O(CF2)2O[CF(CF3)CF2O]2CF(CF3)(CH2)2P(O)(OC6H5)2


(C6H5O)2P(O)(CH2)2CF(CF3)[OCF2CF(CF3)]2O(CF2)2O[CF(CF3)CF2O]2CF(CF3)(CH2)2P(O)(OH)(OC6H5)


Perfluoropolyether, to which such a fluorine-containing polyether diphosphonic acid ester compound is added and which is used as a base oil, can be represented by the following general formula:

RfO (CF2O)x(C2F4O)y(C3F6O)zRf

where x+y+z=2-200, and one or two of x, y and z can be 0. Specifically, those represented by the following general formulae (1)-(3) can be used, and also the one represented by the following general formula (4) can be also used. Rf is a perfluoro lower alkyl group having 1-5 carbon atoms, preferably 1-3 carbon atoms, such as a perfluoromethyl group, a perfluoroethyl group, a perfluoropropyl group, etc.


(1) RfO(CF2CF2O)m(CF2O)nRf


where m+n=3-200, and m:n=10-90:90-10. The CF2CF2O group and the CF2O group are bonded to the main chain at random. The compound (1) can be obtained by complete fluorination of a precursor formed by photooxidation polymerization of tetrafluoroethylene.


(2) RfO [CF(CF3) CF2O]p(CF2CF2O)q(CF2O)rRf


where p+q+r=3-300, q and r can be 0, and (q+r)/p=0.2. The CF(CF3)CF2O group, the CF2CF2O group, and the CF2O group can be bonded to the main chain at random. The compound (2) can be obtained by complete fluorination of a precursor formed by photoxidation polymerization of hexafluoropropene and tetrafluoroethylene.


(3) RfO[CF(CF3)CF2O]s(CF2CF2O)tRf


where s+t=2-200, and t can be 0, and t/s=0-2, and the CF(CF3)CF2O group and the CF2CF2O group can be bonded to the main chain at random. The compound (3) can be obtained by complete fluorination of a precursor formed by photooxidation polymerization of hexafluoropropene and tetrafluoroethylene, or by anionic polymerization of hexafluoropropylene oxide, or tetrafluoroethylene oxide in the presence of a cesium fluoride catalyst, followed by treatment of the resulting acid fluoride compound having a terminated —CF(CF3)COF group with a fluorine gas.


(4) F(CF2CF2CF2O)2˜100C2F5


The compound (4) can be obtained by anionic polymerization of 2,2,3,3-tetrafluorooxetane in the presence of a cesium fluoride catalyst, followed by treatment of the resulting fluorine-containing polyether (CH2CF2CF2O)n with a fluorine gas at about 160° to about 300° C. under ultraviolet ray irradiation.


These perfluoropolyether base oils can be used alone or in a mixture, and in the case of using them as a lubricating oil, it is desirable that their viscosity (40° C.) is about 5 to about 2,000 mm2/sec, preferably about 10 to about 1,500 mm2/sec. When the viscosity is below about 5 mm2/sec, no oil films can be maintained at high temperatures, resulting in abrasion of lubricated surfaces, whereas above about 2,000 mm2/sec, the pour point (according to JIS K-2283) will be 10° C. or higher, so bearings, gears, chains, etc. will fail to work at low temperatures in the ordinary procedure, additional heating will be necessary for their working, consequently lacking in the necessary qualifications for use as the normal oil. The base oils can be used as grease by adding a thickening agent thereto. When the viscosity is below about 5 mm2/sec in that case, evaporation amount will be increased, failing to satisfy the conditions that the evaporation amount must be not more than 1.5%, as set forth according to JIS ball-and-roller bearing grease, class 3, for the heat resistant grease, whereas when the viscosity is above about 2,000 mm2/sec, the pour point (according to JIS K-2283) will be 10° C. or higher, same as in the case of the lubricating oil, and bearings, gears, chains, etc. will fail to work at low temperatures in the ordinary manner, and additional heating is necessary for their working, consequently lacking in the necessary qualifications for use as the normal grease.


When the fluorine-containing polyether diphosphonic acid ester compound is added to the perfluoropolyether base oil to prepare a lubricating oil composition, the diphosphonic acid ester compound can be used in a proportion of about 0.1 to about 20% by weight, preferably about 0.5 to about 5% by weight, on the basis of the composition consisting of these two components. If the proportion is below about 0.1% by weight, no sufficient effect of a lubricating oil can be obtained, whereas, even if used in a proportion of more than about 20% by weight, no such properties as to meet the cost performance can be obtained.


An effective grease composition can be prepared also with respect to the sealability by adding a thickening agent to such a lubricating oil composition. As a thickening agent, polytetrafluoroethylene [PTFE], tetrafluoroethylene-hexafluoropropene copolymer [FEP], perfluoroalkylene resin, etc., which have been so far used as a lubricating oil, can be also used. Polytetrafluoroethylene, prepared by emulsion polymerization, suspension polymerization, solution polymerization, etc. of tetrafluoroethylene, and further treated by thermal decomposition, electron beam irradiation, physical pulverization, etc. to reduce the number average molecular weight Mn from about 1,000 to about 1,000,000 down to about 1,000 to about 500,000, can be used. Copolymerization reaction of tetrafluoroethylene and hexafluoropropene, and successive treatment to lower the molecular weight can be carried out as in the case of polytetrafluoroethylene, and the resulting tetrafluoroethylene-hexafluoropropene copolymer having a lowered number average molecular weight Mn of about 1,000 to about 600,000 can be used. Control of the molecular weight can be also carried out by a chain transfer agent at the time of copolymerization reaction. The resulting powdery fluorine resin has usually a melting point of about 250° to about 340° C., and an average primary particle size of not more than about 500 μm, preferably about 0.1 to about 30 μm.


As other thickening agent than these fluoro resins, a metal soap such as Li soap, etc., urea resin, minerals such as bentonite, etc., an organic pigment, polyethylene, polypropylene, and polyamide can be also used. In view of the heat resistance and lubricating properties, aliphatic dicarboxylic acid metal salts (e.g. dilithium azelate), monoamide-monocarboxylic acid metal salts, monoester carboxylic acid metal salts, diurea, triurea, tetraurea, etc. can be used.


These fluoro resin powder, metal soap, urea, and other thickening agents can be used in a proportion of 0.1-50% by weight, preferably 10-40% by weight, on the basis of total with the base oil and the additive. When these thickening agents are used in a proportion of more than 50% by weight, the composition will be too hard, whereas in a proportion of less than 0.1% by weight, the thickening effect of the fluoro resin, etc. cannot be shown, resulting in acceleration of oil separation, and any improvement of anti-scattering and anti-leakage properties cannot be fully expected. The fluorine-containing polyether diphosphonic acid ester can be used in a proportion of about 0.1 to about 20% by weight, preferably about 0.5 to about 5% by weight, on the basis of the composition comprising these three components, as in the case of the lubricating oil composition.


The composition can contain, if necessary, other additives such as an antioxidant, a rust preventive, a corrosion inhibitor, an extreme pressure additive, an oiliness agent, a solid lubricant, etc., which have been so far used in the lubricant. The antioxidant includes, for example, a phenolic antioxidant such as 2,6-t-butyl-4-methylphenol, 4,4′-methylenebis(2,6-t-butylphenol), etc., and an amine-based antioxidant such as alkyldiphenylamine, triphenylamine, phenyl-α-naphthylamine, phenothiazine, alkylated phenyl-α-naphthylamine, phenithazine, alkylated phenithiazine, etc.


The rust preventive includes, for example, fatty acids, fatty acid amines, alkylsulfonic acid metal salts, alkylsulfonic acid amine salts, paraffin oxides, polyoxyethylene alkyl ether, etc. and the corrosion inhibitor includes, for example, benzotriazole, benzoimidazole, thiadiazole, etc.


The extreme pressure agent includes, for example, a phosphorus-based compound such as phosphoric acid esters, other phosphorous acid ester, phosphoric acid ester amine salts, etc., and a sulfur-based compound such as sulfides, disulfides, etc., a metal salt of sulfur-based compound such as dialkyldithiophosphoric acid metal salts, dialkyldithiocarbamic acid metal salts etc.


The oiliness agent includes, for example, fatty acids or their esters, higher alcohols, polyhydric alcohols, or their esters, aliphatic amines, fatty acid monoglycerides, etc. The other solid lubricant includes, for example, molybdenum disulfide, graphite, boron nitride, silane nitrides, etc.


Preparation of the composition can be carried out as follows a lubricating oil composition can be readily prepared by adding a fluorine-containing polyether diphosphonic acid ester to a perfluoropolyether base oil, followed only by stirring, and a grease composition can be prepared by a method (a) of adding predetermined amounts of a fluorine-containing polyether diphosphonic acid ester synthesized in advance, a thickening agent, and other necessary additives to a perfluoropolyether base oil, followed by thorough kneading through three rolls or in a high pressure homogenizer, or by a method (b) of adding a perfluoropolyether base oil and an aliphatic carboxylic acid to a heating and stirrable reactor vessel, then adding a predetermined amount of a metal hydroxide (and amine or alcohol) thereto to initiate a metal salt formation reaction (and amidization reaction or esterification reaction), followed by cooling, and further adding a fluorine-containing polyether diphosphonic acid ester thereto, followed by through kneading through three rolls or in a high pressure homogenizer.







EXAMPLES

The present invention will be described in detail below, referring to Examples.


Examples 1 to 12, and Comparative Examples 1 to 9

Base oil A: RfO[CF(CF3)CF2O]pRf Viscosity (40° C.) 100 mm2/sec.


B: RfO[CF(CF3)CF2O]pRf Viscosity (40° C.) 400 mm2/sec


C: F(CF2CF2CF2O)uRf Viscosity (40° C.) 100 mm2/sec


D: RfO(CF2CF2O)m(CF2O)nRf Viscosity (40° C.) 160 mm2/sec


E3[CF2O]p(CF2O)rRf Viscosity (40° C.) 230 mm2/sec


Additive I: R1,R2,R3,R4=C2H5, a,c,e=2, b,d=1


II: A mixture (wt. ratio=3:1) of R1,R2,R3,R4=C6H5, a,b,c,d,e=2, and R1,R2,R3=C6H5, R4=H, a,b,c,d,e=2


III: A mixture (wt. ratio=1:2:1) of R1,R2,R3,R4=C3H7, 2≦a+e ≦6, 2≦b+d≦6, c=4, R1,R2,R3=C3H7, R4=H, 2≦a+e=≦6, 2≦b+d ≦6, c=4, and R1, R2, R3, R4=H. 2≦a+e≦6, 2≦b+d ≦6, c=4


IV: A mixture (wt. ratio=1:2:1) of R1,R2,R3,R4=C6H,11, a,c,e=2, b,d=1, R1, R2=C6H11, R3,R4=C6H4CH3, a,c,e=2, b,d=1, and R1,R2,R3,R4=C6H4CH3, a,c,e=2, b,d=1


V: R1,R2,R3,R4=C3H7, a,e=2, c=6, 10≦b+d≦16


VI: C3F7O[CF2CF(CF3)O]vCF(CF3)(CH2)2PO(OC2H5)22≦v≦6


VII: C3F7O[CF2CF(CF3)O]vCF(CF3)(CH2)2PO(OC6H5)22≦v≦8


VIII: C3F7O[CF2CF(CF3)O]vCF(CF3)(CH2)2OPO(OC2H5)22≦v≦6


The afore-mentioned base oil and additive could be readily mixed only with stirring, whereby lubricating oil compositions could be prepared.

TABLE 1Base oilAdditiveExamplesSpecieswt. %Specieswt. %Example 1A99.5I0.5Example 298.0II2.0Example 390.0I10.0Example 498.0II2.0Example 599.0IV1.0Example 6B99.0V1.0Example 795.0I5.0Example 8C97.0III3.0Example 995.0II5.0Example 10D99.0V1.0Example 11E95.0II5.0Example 1285.0IV15.0Comp. Ex. 1A100.0Comp. Ex. 2B100.0Comp. Ex. 3A98.0VI2.0Comp. Ex. 499.0VII1.0Comp. Ex. 5B95.05.0Comp. Ex. 6C97.0VI3.0Comp. Ex. 7D99.01.0Comp. Ex. 8E95.0VII5.0Comp. Ex. 9A98.0VIII2.0


These lubricating oil compositions were subjected to the following tests to determine abrasion marks, friction coefficient and rust preventiveness. The results are shown in the following Table 2.


<Shell Abrasion Test>


Test pieces [SUJ2(a half inch), grade 20] were subjected to an abrasion test under such conditions as revolution rate: 20 revolutions/sec., load: 392.3N (40 kgf), temperature:room temperature, and time: 60 minutes, using a Shell Four-Ball Wear test machine to determine abrasion mark sizes formed on the test pieces after the test


<Pendulum Test>


Aida type pendulum type friction tester was used under such conditions as a ball: SUJ2( 3/16 inch), a roller pin: SUJ2, temperature:room temperature, and load: 80g at the right and left sides and 40 g at the center to determine a friction coefficient <Humidity Test>


Humidity test pieces (material: SPCC-SB, and dimension: 1.2 mm×60 mm×80 mm) were dipped into individual lubrication oil compositions, and then suspended in the humidity cabinet of the test apparatus at a temperature of 49°±1° C. and a humidity of 95% or higher and maintained in that state for 300 hours. Then, the test pieces were taken out of the tank to determine the degree of rust generation. The degree of rust generation is classified in the following rankings.

RankingDegree of rust generation (%)A0B 1˜10C11˜25D26˜50E 51˜100


<Heating Test>


50 ml of a mixture of a base oil and an additive was charged into a beaker having a capacity of 100 ml, and then the beaker was left to stand in a thermostat tank heated to 200° C. for 100 hours. After the test, changes in the appearance was visually inspected.

TABLE 2Shell abrasion testPendulum testHumidity testHeating testAbrasion markFrictionRust preventiveChange inExamplessize (mm)coefficientrankingappearanceExample 10.330.114ANo changesExample 20.300.111AExample 30.270.108AExample 40.320.112AExample 50.310.114AExample 60.320.115AExample 70.350.115AExample 80.360.110AExample 90.370.108AExample 100.390.009AExample 110.320.113AExample 120.310.105AComp. Ex. 10.610.135EComp. Ex. 20.720.133EComp. Ex. 30.380.117BComp. Ex. 40.750.114DComp. Ex. 50.720.119DComp. Ex. 60.470.114BComp. Ex. 70.490.113CComp. Ex. 80.690.120DComp. Ex. 90.670.120BChangedto brown(turbidity)


Examples 13 to 25, and Comparative Examples 10 to 18

Grease compositions were prepared from the afore-mentioned base oils and additives together with the following thickening agents by the afore-mentioned preparation method (a) [but in the case of using the following thickening agent d by the afore-mentioned preparation method (b)].


Thickening agent a: Emulsion-polymerized PTFE (Mn: 105˜2×105; melting point: 330° C.; average primary particle size: 0.2 μm)

    • b: Suspension-polymerized PTFE (Mn: 104˜105; melting point: 318° C.; average primary particle size: 5 μm)
    • c: Solution-polymerized FEP (Mn: 5×104˜15×104; melting point: 256° C. average primary particle size : 0.2 μm)


d: Dilithium azelate LiOOC(CH2)7COOLi

TABLE 3Base oilAdditiveThickening agentExamplesSpecieswt. %Specieswt. %Specieswt. %Example 13A77.5I1.5a22.0Example 1475.0II5.020.0Example 15B70.0III2.028.0Example 1665.0IV3.032.0Example 1765.0V5.030.0Example 1864.0II1.0b35.0Example 1960.0I10.0 d30.0Example 20C70.50.5a29.0Example 2167.0II3.030.0Example 22D57.0IV5.0b38.0Example 2369.0V1.0c30.0Example 24E65.0III3.0a32.0Example 2555.0I18.0 c27.0Comp. Ex. 10C65.0a35.0Comp. Ex. 11D70.030.0Comp. Ex. 12E85.0d15.0Comp. Ex. 13A75.0VI5.0a20.0Comp. Ex. 1478.0VII2.020.0Comp. Ex. 15B72.0VI3.025.0Comp. Ex. 16C68.51.5b30.0Comp. Ex. 17D62.03.035.0Comp. Ex. 18E65.0VII5.0c30.0


The grease compositions were tested to determine the abrasion mark size and corrosion resistance. The results are shown in the following Table 4.


<Shell Abrasion Test>


The same as above


<Emcor test (degree of corrosion) according to DIN 51802>


10 ml of grease was sealed into a 1306K bearing. The bearing was fixed to a SKF Emcor Method testing machine and tested in such a cycle condition as a revolution rate of 80 rpm, and revolution cycle of revolution continuation for 8 hours→revolution discontinuation for 16 hours→revolution continuation for 8 hours revolution discontinuation for 16 hours→revolution continuation for 8 hours→revolution discontinuation for 108 hours (=total 164 hours) to evaluate the corrosion state on the race way of bearing outer race according to the following evaluation standard. test, an aqueous 0.1 wt. % sodium chloride solution was used.

RantingDegree of CorrosionDescription0No corrosionNothing1Traces of corrosionNot more than 3 corrosion sites,none having a diameter greaterthan 1 mm2Slight corrosionCorrosion covering not more than1% of surface, but or largercorrosion sites than for rating 13Moderate corrosionCorrosion covering more than 1%,but not more than 5% of surface4Severe corrosionCorrosion covering more than 5%,but not more than 10% of surface5Very severe corrosionCorrosion covering more than 10%of surface













TABLE 4












Shell abrasion test
Emcor test



Examples
Abrasion mark size (mm)
Rating









Example 13
0.66
0



Example 14
0.62
0



Example 15
0.71
0



Example 16
0.69
0



Example 17
0.67
0



Example 18
0.73
0



Example 19
0.65
0



Example 20
0.79
0



Example 21
0.98
0



Example 22
0.97
0



Example 23
0.99
0



Example 24
0.70
0



Example 25
0.60
0



Comp. Ex. 10
2.88
5



Comp. Ex. 11
3.04
5



Comp. Ex. 12
2.75
5



Comp. Ex. 13
0.74
1



Comp. Ex. 14
2.45
4



Comp. Ex. 15
0.91
1



Comp. Ex. 16
1.01
2



Comp. Ex. 17
1.15
1



Comp. Ex. 18
2.62
3










INDUSTRIAL UTILITY

The present lubricating composition and grease composition can be applied to uses to which perfluoropolyether oil has been so far applied, particularly sliding parts requiring the lubricability or rust preventiveness, or exposed to corrosive gases, for example, sliding parts of ball-and-roller bearings, slide bearings, sintering bearings, gears, valves, cocks, oil seals, electric contacts, etc.


Specifically, they can be effectively applied to sliding parts, for example, bearings requiring the heat resistance, low-temperature characteristics, and load resistance, typically hub units, traction motor, fuel injection systems, alternators, etc. of automobiles; gear parts requiring the wear resistance, low friction characteristics, and high torque efficiency, typically power transmission devices, power wind motors, wipers, etc. of automobiles; bearings requiring a low torque or low outgassing, typically hard disc, flexible disc memory devices, compact disc drives, optomagnetic disc drives used in the information equipment; bearings, gears, etc. used in vacuum pumps, resin production apparatuses, conveyers, lumber industry machinery, chrome coating apparatuses, etc. or electric contacts in electronic devices used in breaker-interrupting devices-relay-switch, etc.

Claims
  • 1. A lubricating oil composition, which comprises a perfluoropolyether base oil, and a fluorine-containing polyether diphosphonic acid ester, represented by the following general formula:
  • 2. A lubricating oil composition according to claim 1, wherein the fluorine-containing polyether diphosphonic acid ester with 2≦c≦10 in the general formula representing the fluorine-containing polyether diphosphonic acid ester is used.
  • 3. A lubricating oil composition according to claim 1, wherein the fluorine-containing polyether diphosphonic acid ester is used in a proportion of 0.1-20 wt. % in the composition.
  • 4. A lubricating oil composition according to claim 1, wherein the perfluoropolyether is a compound represented by the following general formula:
  • 5. A lubricating oil composition according to claim 4, wherein the perfluoropolyether is a compound represented by the following general formula:
  • 6. A lubricating oil composition according to claim 4, wherein the perfluoropolyether is a compound represented by the following general formula:
  • 7. A lubricating oil composition according to claim 4, wherein the perfluoropolyether is a compound represented by the following general formula:
  • 8. A lubricating oil composition according to claim 1, wherein the perfluoropolyether is a compound represented by the following general formula:
  • 9. A grease composition, which comprises a perfluoropolyether base oil, a fluorine-containing polyether diphosphonic acid ester, represented by the following general formula:
  • 10. A grease composition according to claim 9, wherein the fluorine-containing polyether diphosphonic acid ester with 2≦c≦10 in the general formula representing the fluorine-containing polyether diphosphonic acid ester is used.
  • 11. A grease composition according to claim 9, wherein the fluorine-containing polyether diphosphonic acid ester is used in a proportion of 0.1-20 wt. % in the composition.
  • 12. A grease composition according to claim 9, wherein the thickening agent is used in a proportion of 0.1-50 wt. % in the composition.
  • 13. A grease composition according to claim 9, wherein the perfluoropolyether is a compound, represented by the following general formula:
  • 14. A grease composition according to claim 13, wherein the perfluoropolyether is a compound, represented by the following general formula:
  • 15. A grease composition according to claim 13, wherein the perfluoropolyether is a compound, represented by the following general formula:
  • 16. A grease composition according to claim 13, wherein the perfluoropolyether is a compound, represented by the following general formula:
  • 17. A grease composition according to claim 9, wherein the perfluoropolyether is a compound, represented by the following general formula:
Priority Claims (1)
Number Date Country Kind
2004-339862 Nov 2004 JP national
PCT Information
Filing Document Filing Date Country Kind 371c Date
PCT/JP05/21526 11/24/2005 WO 5/21/2007