CN101128569B

CN101128569B - Lubricant

Info

Publication number: CN101128569B
Application number: CN2006800057624A
Authority: CN
Inventors: 桥田幸; 泽口涉; 新田敏夫; 桥本达也; 志村明彦; 百合本次郎
Original assignee: Nok Klueber Co Ltd
Current assignee: Nok Klueber Co Ltd
Priority date: 2005-02-22
Filing date: 2006-02-17
Publication date: 2012-12-12
Anticipated expiration: 2026-02-17
Also published as: KR100900748B1; US20080167208A1; KR20070054179A; JP4697225B2; WO2006090641A1; JPWO2006090641A1; CN101128569A; DE112006000066T5

Abstract

A lubricant comprising a lubricating oil or grease which contains as a base oil a perfluoropolyether oil having a dynamic viscosity at 40 DEG C of 50-1,500 mm2/sec and containing no (CF2O)n groups as repeating units for the polymer. The lubricant is usable in applications where it comes into contact with graphite or molybdenum disulfide or applications where it comes into contact with an aluminum material. As the perfluoropolyether base oil is used F(CF2CF2CF2O) mC2F5 or RfO[CF(CF3)CF2O]p(CF2CF2O)qRf'. Even when this lubricant is used in various applications such as those, the high-temperature characteristics (high-temperature durability) are not considerably impaired. When the base oil has a dynamic viscosity of 50-250 mm2/sec, the lubricant is excellent also in low-temperature characteristics.

Description

Lubricant

Technical field

The present invention relates to a kind of lubricant.Relate to a kind of lubricant that contains lubricating oil or railway grease in more detail, it is used for contacting with the graphite or the molybdenumdisulphide of the sintered metal bearing that contains graphite or molybdenumdisulphide etc., perhaps is used for contacting with the aluminium of the slide unit that uses aluminium etc.

Background technology

Sintered metal bearing is made up of the porous plastid that the multiple pressed powder of compression forms, and wherein pressed powder obtains through in metal-powders such as iron, copper, tin, zinc, adding solid lubricants such as graphite, molybdenumdisulphide, carbon black.Sintered metal bearing is through the self-lubricating function of the less amount of lubrication oil generation of initial stage dipping, thereby non-refuelling also can be used.Therefore, can keep the lubricant of sufficient quantity for a long time in the bearing, and can stably use, this life-span for bearing is very important.

Bearing as automobile; The service condition of the sintered metal bearing more cheap than ball-and-roller bearing increases day by day, and used lubricant is in special attention high temperature durability and cold property etc. inevitably lubricant is required in the environment of strictness more in this sintered metal bearing.For this purpose; Use is with the lubricating oil composition of perfluoro polyether oil as base oil; But such base oil also has very large surface-area so that can contact coexistence with multiple metal or solid lubricant, so even perfluoro polyether oil can not be kept the stable hot properties that depends on its structure.

Patent documentation 1: Japanese Patent the 2nd, 595, No. 583 communiques

Aluminium is light but specific tenacity is bigger; Through it can be obtained higher intensity as alloy or enforcement processing; And have erosion resistance, so can be used for from the slide unit to the trolley part, various uses such as aviation ship components, tame electrical article, power tool class.They to the lightweight of various machineries, improve high-speed rotary part or slide unit working efficiency, saving energy all has contribution.These use lubricant used in the parts of aluminium also to need stably to keep excellent performance.

Summary of the invention

The hot properties of discovery perfluoro polyether oils such as the inventor not exclusively depends on its structure, through with sintered metal bearing in the graphite or the molybdenumdisulphide that use as a kind of composition contact rapid reduction hot properties.And, find that perfluoro polyether oil contacts with aluminium, its hot properties also can sharply reduce.

The purpose of this invention is to provide a kind of lubricant that also can significantly not damage hot properties (high temperature durability) in following situation; These situations comprise: be used for contacting with the graphite or the molybdenumdisulphide of the sintered metal bearing that contains graphite or molybdenumdisulphide etc., with situations such as the metal parts of the spot contact bearing that contains graphite or molybdenumdisulphide etc. contacts, perhaps be used for the situation that contacts with aluminium (comprise as slide unit and use aluminium).

Lubricant through having following condition reaches the object of the invention, and this lubricant uses the repeating unit as polymkeric substance not contain (CF ₂O) _nThe perfluoro polyether oil of base is as base oil, and wherein the dynamic viscosity of perfluoro polyether oil under 40 ℃ is 50～1500mm ²/ second, preferred 50～250mm ²/ second, preferred especially 65～200mm ²/ second, and this lubricant can be used for contacting with graphite or molybdenumdisulphide or being used for contacting with aluminium.Lubricant can be any form of lubricating oil or railway grease.Here, as the PFPE base oil, use the perfluoro polyether oil of representing by formula.

F(CF ₂CF ₂CF ₂O) _mC ₂F ₅

RfO[CF(CF ₃)CF ₂O] _p(CF ₂CF ₂O) _qRf’

The hot properties of perfluoro polyether oil (high temperature durability) also not exclusively depends on its structure; Through with sintered metal bearing in the graphite or the molybdenumdisulphide that use as a kind of composition contact; Can sharply reduce hot properties; But can provide a kind of according to the present invention and also can significantly not damage the lubricant of hot properties in following situation, these situations comprise: be used for contacting, be used for and contain the situation that the metal parts of the spot contact bearing etc. of graphite or molybdenumdisulphide contacts with the graphite or the molybdenumdisulphide of sintered metal bearing that contains graphite or molybdenumdisulphide etc.In addition, when being used for contacting, comprise the atmosphere that is used to disperse or has sneaked into graphite or molybdenumdisulphide, situation that for example contacts etc. with graphite or molybdenumdisulphide from motor components such as brush, axles with metal parts.The atmosphere of dispersing or having sneaked into graphite or molybdenumdisulphide is not limited to these situations.

Dynamic viscosity under 40 ℃ is 50～1500mm ²/ second said perfluoro polyether oil, in the presence of solid lubricants such as graphite, molybdenumdisulphide, even use down surpassing 150 ℃ high temperature, also can long term maintenance volatility and stability, use the parts acquisition long lifetime thereby make.Particularly dynamic viscosity is 50～250mm ²/ second, preferred 65～200mm ²The perfluoro polyether oil of/second also has excellent cold property.

This lubricant be applicable to comprise rotation, back and forth, slide, the material of the various slip forms of swing; For example can enumerate: as sintered metal bearing that contains graphite or molybdenumdisulphide or axle bush; As fuel injection device such as the number control device that dallies, ERG, electronic throttle gear and be the purposes that requires thermotolerance, low temperature properties, anti-loading property of representative with hub unit, traction engine, alternator etc., be the car applications such as purposes that require wear resistant or low rubbing characteristics of representative with power transmission, power-operated window for vehicle mover, wiper etc.; Be used for hard disk drive, diskette storage device, CD drive, magneto optical driver etc. is the information machine purposes of the requirement high speed, low-friction coefficient of representative, low degassing property etc.; Being used for LBP scanning device mover etc. is the business machine purposes of representative; The mover purposes etc. that is used for other the tame electrical article that can under hot environment, use, sound equipment articles for use etc.Also can be applicable to effectively other contact or sneaked into the purposes of using under the environment of graphite or molybdenumdisulphide.

The hot properties of perfluoro polyether oil (high temperature durability) in that when contact, this characteristic sharply reduces with aluminium (comprise as slide unit use aluminium), can significantly not damage hot properties when still lubricant of the present invention is used for this situation.That is, under the coexistence of aluminium, even use lubricant of the present invention surpassing under the hot conditions of 150 ℃ or 200 ℃, also can long term maintenance volatility and stability, through in various slips, bringing into play oilness, thereby use parts to obtain extra long life.

Except that these purposes, this lubricating oil also can be used for the bearing or the axle bush of chain used in warming mill, building machinery, work mechanism, power tool, printing bookbinding sheet processing machinery or their parts of plastic working device, business machine, duplicating machine etc.; Can also be further used for the lubricated of contact position between the sliding position individuality of ball-and-roller bearing, sliding surface bearing, sintered bearing, gear, valve, stop valve, oil sealing, beaming roller, electrical pickoff etc.

Description of drawings

Fig. 1 is in the presence of graphite or molybdenumdisulphide, 200 ℃ down various PFPE base oils the weight decrement through the time change synoptic diagram.

Embodiment

Dynamic viscosity (JIS K2283 benchmark under using 40 ℃ as base oil; Corresponding to ASTMD445) be 50～1500mm ²/ second, preferred 50～250mm ²/ second, preferred especially 65～200mm ²/ second, and do not contain (CF as the repeating unit of polymkeric substance ₂O) _nThe base oil of base.As after state embodiment 1 with shown in Fig. 1 chart, be determined at perfluoro polyether oil when leaving standstill in 200 ℃ the thermostatic bath through the time change (the weight decrement of oil), contain (CF as the repeating unit of polymkeric substance ₂O) _nThe perfluoro polyether oil of base through the time change with the situation that does not have graphite or molybdenumdisulphide under other perfluoro polyether oil compare; Its weight decrement through the time to change not be remarkable especially, if but with graphite or molybdenumdisulphide coexistence then should through the time change remarkable especially; Do not contain (CF as repeating unit on the other hand ₂O) _nThe perfluoro polyether oil of base, even under the coexistence of graphite or molybdenumdisulphide, this characteristic only has subtle change, does not contain (CF so can use as repeating unit ₂O) _nThe perfluoro polyether oil of base is as base oil.。

As after state shown in the result of embodiment 2, even under the coexistence of aluminium, lubricant of the present invention is under 250 ℃ high temperature, its weight decrement and also is same result-40 ℃ dynamic viscosity also in the scope of allowing.

Repeating unit as polymkeric substance does not contain (CF ₂O) _nThe perfluoro polyether oil (base oil) of base, the perfluoro polyether oil of the formula that for example can be listed below.

(A)F(CF ₂CF ₂CF ₂O) _mC ₂F ₅

(B)RfO[CF(CF ₃)CF ₂O] _p(CF ₂CF ₂O) _qRf’

(wherein, Rf and Rf ' are that identical or mutually different carbonatoms is 1～5 perfluoroalkyl).

Perfluoro polyether oil (A): through in the presence of the cesium fluoride catalyzer 2,2,3,3-tetrafluoro trimethylene oxide carries out anionoid polymerization, again with gained fluorochemical polyether (CH ₂CF ₂CF ₂O) _nUnder 160～300 ℃ uviolizing, handle and to obtain perfluoro polyether oil (A) with fluorine gas.Its dynamic viscosity that can use under 40 ℃ is 5～2000mm ²/ second perfluoro polyether oil, this perfluoro polyether oil satisfies the condition of m=2～100 in the general formula of perfluoro polyether oil (A).

Perfluoro polyether oil (B): through fluoridizing fully with the precursor that tetrafluoroethylene carries out photoxidation polymerization generation by R 1216 or its; Perhaps carry out anionoid polymerization with the tetrafluoroethylene oxide compound, again gained is had terminal CF (CF through hexafluoropropene oxide in the presence of the cesium fluoride catalyzer or its ₃) acyl fluorides of COF base handles with fluorine gas and can obtain perfluoro polyether oil (B).Its dynamic viscosity that can use under 40 ℃ is 5～2000mm ²/ second perfluoro polyether oil, this perfluoro polyether oil satisfies the condition of p+q=2～200, q/p=0～2 in the general formula of perfluoro polyether oil (B).

Dynamic viscosity is 50mm ²/ second following perfluoro polyether oil, it is big that vaporization losses rate (weight decrement) becomes, and the oil film strength reduction etc., thereby causing lifetime or cause abrasion, Cylinder sticking, dynamic viscosity is 1500mm on the other hand ²/ second above perfluoro polyether oil, it is very high that pour point becomes, and not only can not obtain sufficient cold property, and because the increase of viscous resistance causes the problem that consumer motivation or torque increase, so if be 50～1500mm as the dynamic viscosity under 40 ℃ of the base oils ²/ second then can bring into play sufficient heat-resistant stability, particularly under coldcondition for example-40 ℃, when requiring to have good cold property, only limiting to use dynamic viscosity is 50～250mm ²/ second, preferred 65～200mm ²The perfluoro polyether oil of/second.Perfluoro polyether oil with such dynamic viscosity not only satisfies sufficient anti-vaporization losses characteristic or cold property, and also can stably use above under 200 ℃ the hot conditions.But also can mix the perfluoro polyether oil that uses more than 2 kinds, at this moment mixing base oil must be in above-mentioned scope in the dynamic viscosity under 40 ℃.

Can add the use thickening material in such base oil, preferably use fluoro-resin.As fluoro-resin, can use over as the tetrafluoroethylene of lubricant, tetrafluoraoethylene-hexafluoropropylene copolymer, perfluorinated alkylidene resin etc.It is about tetrafluoroethylene of about 1000～1000000 that methods such as the emulsion polymerization through tetrafluoroethylene, suspension polymerization, solution polymerization are made number-average molecular weight Mn; Then it is handled through methods such as thermolysis, electron rays irradiation decompositions, physical pulverization, use number-average molecular weight Mn is about about 1000～500000.In addition, the copolymerization of tetrafluoroethylene and R 1216 and lower molecular weight processing also with the same the carrying out of situation of tetrafluoroethylene, use number-average molecular weight Mn to be about about 1000～600000.Can when copolyreaction, use chain-transfer agent to carry out the control of molecular weight.The Powdered fluoro-resin of gained generally has below about 500 μ m, the average primary particle diameter of preferred about 0.1～30 μ m.Add pulverous fluoro-resin and can give oil film formability, the anti-leaks of dispersing, rust-preventing characteristic, and can further improve oilness and weather resistance.

As the thickening material except that fluoro-resin; Can use mineral substance such as metallic soap, urea-formaldehyde resin, wilkinite, pigment dyestuff, Vilaterm, Vestolen PP 7052, polymeric amide etc. such as Li soap; If consider from thermotolerance, oilness aspect, preferably use aliphatic dicarboxylic acid metal-salt, monoamide monocarboxylic acid metal-salt, monoesters carboxylic metallic salt, allophanamide, triuret, four ureas etc.

The interpolation blending ratios of thickening material in the perfluoro polyether oil base oil such as these fluororesin powders are 0.1～40 weight % of total composition, preferred 0.5～30 weight %.If adding proportion is more than it, then compsn is really up to the mark, cause can not bearing enclosed grade in; On the other hand; If adding proportion below it, then can not be brought into play the thickening capabilities of fluoro-resin, AV reduces; Dispersiveness in base oil worsens, thereby can't improve oil film formability, anti-leaks and the rust-preventing characteristic of dispersing.The adding proportion of thickening material be thickening material and base oil total amount a little less than then forming railway grease about 10 weight %; After state in embodiment and the comparative example; The ratio of thickening material is that 5 weight % are when following; Belong to the category of " liquid railway grease " and demonstrate flowability, so the evaluation of cold property is represented with the low temperature viscosity of base oil mixture.On the other hand, the ratio of thickening material is in the example of 30 weight %, owing to the category that belongs to railway grease becomes semi-solid, so the evaluation of cold property is represented with the evaluation result of low temperature torque.

Further; In the scope of not damaging the object of the invention; Can add as required and use the plain type additive of previously known fluorine, for example the end of perfluoro polyether oil is by the substituted compounds such as resultant of reaction of ethanol, carboxylic acid or its ester, amine, acid amides, phosphoric acid or its ester, phosphonic acids or its ester, isocyanic ester and ethanol or amine.

Owing to added fluoro-resin, before can also further adding in the lubricant base oil as required and the additive that adds in the lubricant before the immiscible various non-fluorine element class additive of perfluoro polyether oil, viscosity index improver, pour point depressant, ashless dispersant, metal species sanitising agent, inhibitor, rust-preventive agent, sanitas, skimmer, extreme-pressure additive, oiliness improver, friction modifier, solid lubricant etc.

As inhibitor, for example can enumerate: 2,6 di tert butyl 4 methyl phenol, 4,4 '-methylene-bis phenol inhibitors such as (2,6 di t butyl phenols); Has carbonatoms and is the amine antioxidants such as alkyl diphenylamine, triphenylamine, PA, alkylation-alpha-naphthylamine, thiodiphenylamine, alkylated phenthazine of 4～20 alkyl.

As rust-preventive agent, for example can enumerate: lipid acid, fatty acid amine, alkylsulphonic acid metal-salt, alkylsulphonic acid amine salt, oxidized petroleum wax, Voranol EP 2001 etc., as sanitas, for example can enumerate: benzotriazole, benzoglyoxaline, thiadiazoles etc.

As extreme-pressure additive, for example can enumerate: Phosphorus compounds such as SULPHOSUCCINIC ACID ESTER, phosphorous acid ester, phosphate amine salt; Sulphur such as sulfide, disulphide compounds; Dialkyl dithiophosphoric acid metal-salt, dialkyldithiocarbamacompositions metal-salt etc.

As oiliness improver, for example can enumerate: lipid acid or its ester, higher alcohols, polyvalent alcohol or their ester, fatty amine, glycerine monofatty ester etc.

As solid lubricant, for example can enumerate: graphite, molybdenumdisulphide, SP 1, silicon nitride etc., when using graphite or molybdenumdisulphide as solid lubricant, can also prevent the PFPE base oil effectively heat-resisting through the time reduction that changes.

In the PFPE base oil, add the compsn that thickening material forms, for example can prepare according to method described as follows.

(a) add the thickening material of specified quantitative in the PFPE base oil respectively; The method of fully mediating with triple-roller mill or high pressure homogenizer; (b) toward adding perfluoro polyether oil and aliphatic carboxylic acid and heating and melting in the reaction kettle of heated and stirred; Carry out metal salinization reaction (and amidate action or esterification) and cooling toward the metal hydroxides (and amide compound or alkylol cpd) that wherein adds specified quantitative then; The method of fully mediating with triple-roller mill or high pressure homogenizer again; Perhaps (c) adds perfluoro polyether oil and isocyanic ester and heating in can the reaction kettle of heated and stirred, and the past then amine that wherein adds specified quantitative reacts and cools off the method for fully mediating with triple-roller mill or high pressure homogenizer again.

Embodiment

Below through embodiment the present invention is described more specifically, but the present invention does not receive the restriction of these embodiment.

Embodiment 1

Admixed graphite powder (black japan leadwork flakey blacklead powder CB-150 in following 3 kinds of PFPE base oils; Fixed carbon content is more than 98.0%, median size 40 μ m) or molybdenumdisulphide (the lubricated goods LM13-SM powder in big east; Median size 0.4 μ m), in sample, be the amount of 10 weight %, get this test and on the glass dish of diameter 37mm, be coated with into film like equably with sample 0.6g, rest on then in 200 ℃ the thermostatic bath, measure oil the weight decrement through the time change.

The gained result is as shown in Figure 1.

●: F (CF ₂CF ₂CF ₂O) _mC ₂F ₅(40 ℃ of following dynamic viscosity: 100mm ²/ second)

Zero :+graphite

▲: RfO [CF (CF ₃) CF ₂O] _p(CF ₂CF ₂O) _qRf ' (40 ℃ of following dynamic viscosity: 180mm ²/ second)

△ :+graphite

■: RfO (CF ₂CF ₂O) _m(CF ₂O) _nRf ' (40 ℃ of following dynamic viscosity: 160mm ²/ second)

:+graphite

◆ :+molybdenumdisulphide

Can know from the gained result, not contain (CF as the repeating unit of polymkeric substance ₂O) _nThe perfluoro polyether oil of base, 200 ℃ down the weight decrements of oil receive the influences of graphite hardly, relative therewith, contain (CF as the repeating unit of polymkeric substance ₂O) _nThe perfluoro polyether oil of base, because the existence of graphite or molybdenumdisulphide, particularly graphite, nearly all oil vaporization losses all in the extremely short time.

Embodiment 2

Toward the following PFPE base oil (A) with the dynamic viscosity under various 40 ℃ or (B), the aluminum mixture powder is (with the pure medicine goods of light; Purity 99.5%; Median size 53～150 μ m); In sample, be the amount of 10 weight %, get this test and on the glass dish of diameter 37mm, be coated with into film like equably, rest on then in 250 ℃ the thermostatic bath with sample 0.6g; Mensuration is calculated the weight decrement of oil through the whole weight of the glass dish after 100 hours.

Perfluoro polyether oil (A): F (CF ₂CF ₂CF ₂O) _mC ₂F ₅

40 ℃ dynamic viscosity (A-1) 65mm ²/ second

(A-2) 100mm ²/ second

(A-3) 200mm ²/ second

(A-4) 23mm ²/ second

Perfluoro polyether oil (B): RfO [CF (CF ₃) CF ₂O] _pRf '

40 ℃ dynamic viscosity (B-1) 180mm ²/ second

(B-2) 400mm ²/ second

(B-3) 25mm ²/ second

(B-4) 1200mm ²/ second

Perfluoro polyether oil (C): RfO (CF ₂CF ₂O) _m(CF ₂O) _nRf '

40 ℃ dynamic viscosity 140mm ²/ second

In addition, use the polytetrafluorethylepowder powder that emulsion polymerization method obtains (Mn about 50000～100000, average primary particle diameter 0.2 μ m) as fluororesin powder.

The amount (weight part) of the kind of base oil and amount (weight part) and fluoro-resin, and the result of gained: base oil or base oil-fluoro-resin mixture at 40 ℃ dynamic viscosity and pour point (based on JISK2269; Corresponding to ASTM D97), weight decrement and the low temperature viscosity of oil (base oil) (based on JIS K2283 ,-40 ℃ dynamic viscosity; Corresponding to ASTM D445), as shown in table 1 below in the lump.No.1～12 are embodiment, and No.13～15 are comparative example.

Table 1

Can know from above result, use 40 ℃ the not enough 50mm of dynamic viscosity ²/ second perfluoro polyether oil the time (No.13,14), the weight decrement under 250 ℃ enlarges markedly.In addition, use repeating unit to contain (CF as polymkeric substance ₂O) _nDuring the perfluoro polyether oil of base (No.15), 250 ℃ of weight decrements after following 100 hours increase, and most of sample disappears.Relative therewith, the dynamic viscosity of using 40 ℃ is at 50～1500mm ²/ second scope in perfluoro polyether oil the time, under 250 ℃ high temperature the weight decrement still in allowed limits, and 40 ℃ dynamic viscosity is at 50～250mm ²/ second scope in perfluoro polyether oil, in-40 ℃ dynamic viscosities still in above-mentioned scope (No.1～10).

Moreover; For the railway grease that contains A-170 weight part-fluoro-resin 30 weight parts (No.21), A-270 weight part-fluoro-resin 30 weight parts (No.22), B-270 weight part-fluoro-resin 30 weight parts (No.23) and B-370 weight part-fluoro-resin 30 weight parts (No.24); Except that above each item, also carry out the low temperature torque test and (, measure-40 ℃ when starting down and solid periodic value based on JIS K2220.5.14; Corresponding to ASTM D1478).The gained result is as shown in table 2 below.No.24 is a comparative example.

Table 2

Annotate) *: can not measure

Claims

Lubricant with purposes during aluminium contacts, wherein, be 50～250mm with 40 ℃ dynamic viscosities ²/ second, and do not contain (CF as the repeating unit of polymkeric substance ₂O) _nThe base perfluoro polyether oil as lubricating oil,

Wherein perfluoro polyether oil is with general formula

F(CF ₂CF ₂CF ₂O) _mC ₂F ₅

The perfluoro polyether oil (A) of expression, wherein, m is 2～100 integer,

And with general formula

RfO[CF(CF ₃)CF ₂O] _p(CF ₂CF ₂O) _qRf’

The expression perfluoro polyether oil (B) at least a, wherein, Rf and Rf ' are that identical or mutually different carbonatoms is 1～5 perfluoroalkyl, p+q=2～200, q/p=0～2 and q can be 0, CF (CF ₃) CF ₂O base and CF ₂CF ₂The O base is randomly-bonded in main chain.
2. the purposes of the described lubricant of claim 1, the dynamic viscosity of wherein using 40 ℃ is 65～200mm ²The perfluoro polyether oil of/second is as lubricating oil.
3. the purposes of the described lubricant of claim 1 is wherein further mixed thickening material, uses as railway grease.
4. the purposes of the described lubricant of claim 3, wherein thickening material is a fluororesin powder.
5. the purposes of the described lubricant of claim 2 is wherein further mixed thickening material, uses as railway grease.
6. the purposes of the described lubricant of claim 5, wherein thickening material is a fluororesin powder.
7. the purposes of the described lubricant of claim 1, it is used to use the purposes of aluminium as slide unit.
8. the purposes of the described lubricant of claim 2, it is used to use the purposes of aluminium as slide unit.