CN1782043A - Ion liquid lubricant - Google Patents

Abstract

The present invention discloses a kind of ion liquid lubricant. The ion liquid lubricant has the features of very low volatility, high heat stability and excellent viscosity-temperature characteristic. As one kind of lubricant for friction pair of steel/ steel, steel/ aluminum, steel/ copper, steel/ monocrystal silicon, steel/ ceramic, ceramic/ ceramic, etc, it has excellent antifriction and anti-wear performance in eight room temperature or high temperature and in either high load or low load conditions.

Description

A kind of ion liquid lubricant

Technical field

The present invention relates to a kind of ion liquid lubricant.

Background of invention

Lubricant with utmost point low-vapor pressure, high thermal stability and good low-temperature fluidity is the space mechanism pursuing target always.For most of space mechanism, the temperature range in its window is-10～60 ℃, and between 10～50 ℃, environmental quality is microgravity, high vacuum usually.Microgravity is favourable for lubricating, but the environment of high vacuum will produce acid test to lubricant.Though airship or satellite can adopt solid lubricant film, soft metal coating, lubricating grease to lubricate, in general, surpass the space mechanism in 1 year work-ing life, and major part all has liquid lubrication means.Development along with technology, require more and more longer the work-ing life of space mechanism, be 6 months to 1 year the sixties in 20th century in early days, the mid-1960s is 3～5 years, the mid-1970s general requirement 7～10 years, and after the nineties, the life in 20 years of space station technical requirements, the work-ing life in 10～20 years.The sixties in 20th century is early stage, and silicone oil (G.E.Versilube F-50) is 10 ^-7～10 ^-9Under the vacuum of Torr for burn-out life of stainless steel AISI 440C bearing between 1000～4600 hours, but at that time, just be enough to meet the demands.The mid-1960s was also tested the mineral oil of paraffinic base, and bearing life surpasses 12000 hours, and under the same conditions, and dibasic acid esters just is no more than 3600 hours owing to volatilize and lost efficacy.The seventies, Britain has developed two kinds of space lubricating oil: super refined mineral oil BP110 and three ester oil BP135, high vapour pressure and high amount of gas evolved are at that time with molecular seal, anti-migration barrier with hold the oil sump technology and solve.At present PFPE (PFPE) is a most widely used lubricant in the space mechanism, and wherein the most frequently used have Krytox 143AC and a Fomblin Z25.But FomblinZ25 is easily degraded in friction process, and as the lubricant of longer life of space mechanism, the performance of PFPE is still waiting further raising.

Simultaneously, the appearance of high loading, high-performance flight aircraft, a problem of being brought is: oiling system must be worked under higher temperature condition.When estimating Mach 2 ship 2.5, the main body lubricating oil temperature is about 204 ℃; When Mach 2 ship 3, the main body lubricating oil temperature is about 260 ℃.When liquid lubricant was worked under this temperature, foreseeable difficulty was oxidation stability, thermostability, the high volatile volatile of lubricant.U.S. Department of Defense, National Aeronautics and Space Administration propose " Integrated High Performance Turbine Engine Technology ", its objective is in order to satisfy 21 century the double requirement of thrust of turbine engine.The requirement of a key is the new high perofmrnace lubricating oils of exploitation in these technology, can tolerate the high-temperature work environment of engine.

Summary of the invention

The object of the present invention is to provide that a kind of volatility is extremely low, thermostability, ion liquid lubricant that viscosity temperature characteristic is good.

A kind of ion liquid lubricant contains the ionic liquid of 5-95wt% molecular formula (I) and the quaternary phosphonium ionic liquid of 95-5wt% molecular formula (II);

R in the molecular formula (I) ₁For containing the alkyl of 1～4 carbon atom, R ₂For containing the alkyl of 2～20 carbon atoms; X is selected from tetrafluoroborate, hexafluoro-phosphate radical, a kind of in the trifluoromethanesulfonic acid root;

R in the molecular formula (II) ₃For containing the alkyl of 1～8 carbon atom, R ₄For containing the alkyl of 2～20 carbon atoms; Y is selected from tetrafluoroborate, hexafluoro-phosphate radical, a kind of in the trifluoromethanesulfonic acid root.

The preparation method of lubricant of the present invention mixes the ionic liquid process of molecular formula (I) and molecular formula (II), obtains by vibration, ultrasonic dispersing.

Table 1 has been enumerated the ion liquid thermostability of concrete some molecular formula (I):

Table 1

	B108	B206	P308	P206	F203	F206
							Decomposition temperature	365.68℃	370.95℃	330.15℃	356.12℃	445.65℃	386.98℃

B108：R ₁＝CH ₃，R ₂＝n-C ₈H ₁₇，X＝BF ₄ ^-；

B206：R ₁＝C ₂H ₅，R ₂＝n-C ₆H ₁₃ X＝BF ₄ ^-；

P308：R ₁＝C ₃H ₇，R ₂＝n-C ₈H ₁₇，X＝PF ₆；

P206：R ₁＝C ₂H ₅，R ₂＝n-C ₆H ₁₃，X＝PF ₆ ^-；

L-F203：R ₁＝C ₂H ₅，R ₂＝C ₃H ₇，X＝(CF ₃SO ₂) ₂N ^-；

L-F206：R ₁＝C ₂H ₅，R ₂＝n-C ₆H ₁₃，X＝(CF ₃SO ₂) ₂N ^-.

The synthetic method of formula (I) compound is seen R.Hagiwara, Y.Ito, J.FluorineChem., 2000,105,221.

Table 2 has been enumerated the thermostability of the quaternary phosphonium ionic liquid of concrete some molecular formula (II):

Table 2

	P4442B	P4444B	P4446B	P4448B	P44410B	P66614B
							Decomposition temperature	373.10℃	372.07℃	373.94℃	405.69℃	388.48℃	401.85℃

P4442B：R ₁＝R ₂＝R ₃＝n～C ₄H ₉，R ₄＝C ₂H ₅ Y＝BF ₄ ^-

P4444B：R ₁＝R ₂＝R ₃＝n～C ₄H ₉，R ₄＝C ₄H ₉ Y＝BF ₄ ^-

P4446B：R ₁＝R ₂＝R ₃＝n～C ₄H ₉，R ₄＝C ₆H ₁₃ Y＝BF ₄ ^-

P4448B：R ₁＝R ₂＝R ₃＝n～C ₄H ₉，R ₄＝C ₈H ₁₇ Y＝BF ₄ ^-

P44410B：R ₁＝R ₂＝R ₃＝n～C ₄H ₉，R ₄＝C ₁₀H ₂₁ Y＝BF ₄ ^-

P66614B：R ₁＝R ₂＝R ₃＝n～C ₆H ₁₃，R ₄＝C ₁₄H ₂₉ Y＝BF ₄ ^-

The synthetic method of formula (II) compound is seen Christine J.Bradaric.AndrewDownard, Christine Kennedy, Allan J.Robertson and Yuehui ZhouGreen Chemistry, 2003,5,143.

Two kinds of ionic liquids are after mixing, and performance thermolysis property does not separately influence mutually respectively.Therefore, the heat decomposition temperature of the beginning of mixture is that decomposition temperature is minimum in the component, and decomposition temperature is that decomposition temperature is the highest in the component fully.Therefore, compare with single component, the lubricant after the combination has temperature applicable range widely.Compare with PFPE with phosphine nitrile X-1P commonly used at present simultaneously, its spendable temperature range is improved.Temperature range is-10～60 ℃ in the window that most of space mechanism requires, and the present invention to be satisfiable temperature range be-50～350 ℃.

Advantage such as above-mentioned two kinds of ionic liquids have all that volatility is extremely low, thermostability and viscosity temperature characteristic are good.Lubricant of the present invention is compared with PFPE with space lubricant phosphine nitrile X-1P commonly used at present, it comprises that to different friction pairs steel/steel, steel/aluminium, steel/copper, steel/silicon single crystal, steel/pottery, pottery/pottery etc. all show good tribological property, is a kind of emerging, very big lubricating oil system of application future.

The tribological property of ion liquid lubricant adopts Optimol SRV type friction wear testing machine to estimate selected frequency 25Hz, amplitude 1mm, experimental period 30min; Experimentally trying is the SAE52100 steel ball, and the examination dish is the nahlock of radius 19mm.In steel/steel-steel pair, the lubrication failure when load increases to 400N of lubricating oil commonly used such as phosphine nitrile and PFPE, and ionic liquid crest provided by the present invention can reach 1000N.

To other friction pair, also all show good tribological property equally as steel/aluminium, steel/copper, steel/silicon single crystal, steel/pottery, pottery/pottery etc.

Same in steel/steel-steel pair under the load of 300N, phosphine nitrile and PFPE frictional coefficient are respectively 0.080 and 0.110, and ionic liquid provided by the present invention can be reduced to 0.065.And the wear volume of phosphine nitrile and PFPE is respectively 26.42mm under the equal conditions ³And 22.44mm ³, and ionic liquid provided by the present invention can be reduced to 2.13mm ³, the highest 9.89mm that is no more than ³

The frictional coefficient of several friction pairs of table 3 under ion liquid lubricant, phosphine nitrile, PFPE are lubricated:

Table 3

Friction pair ball/dish	Frictional coefficient
							The present invention		The phosphine nitrile		PFPE
	SRV	DF-PM	SRV	DF-PM	SRV	DF-PM
							Steel/steel steel/aluminum steel/copper steel/SiO 2Pottery/SiO 2Steel/Si (100) steel/ceramic/pottery	0.065 0.040 0.025 0.060 0.083 0.050 0.065 0.065	0.082 0.095 0.045 0.075 0.060 0.085 0.065 0.080	0.098 0.128 0.117 0.110 0.115 0.102 0.100 0.105	0.100 0.330 0.110 0.105 0.105 0.090 0.090 0.090	0.145 - 0.145 0.132 0.132 0.145 0.120 0.130	0.120 - 0.120 0.115 0.120 0.120 0.110 0.115

Annotate: SRV is the micro-moving frictional wear trier.

DF-PM is quiet kinetic friction wear testing machine.

SRV: frequency 25Hz, amplitude 1mm, load 50N, room temperature; DF-PM (quiet moving experimental machine):

Speed 150mm/min, unidirectional stroke 10mm, load 1N, room temperature.

Embodiment

Embodiment 1

According to the component and the content (wt%) of table 4, with the compound of formula (I) and formula (II) through mixing after make the ion lubricant after the vibration, ultrasonic dispersing.

Table 4

Claims (1)

1, a kind of ion liquid lubricant contains the ionic liquid of 5-95wt% molecular formula (I) and the quaternary phosphonium ionic liquid of 95-5wt% molecular formula (II);

R in the molecular formula (I) ₁For containing the alkyl of 1～4 carbon atom, R ₂For containing the alkyl of 2～20 carbon atoms; X is selected from tetrafluoroborate, hexafluoro-phosphate radical, a kind of in the trifluoromethanesulfonic acid root;

R in the molecular formula (II) ₃For containing the alkyl of 1～8 carbon atom, R ₄For containing the alkyl of 2～20 carbon atoms; Y is selected from tetrafluoroborate, hexafluoro-phosphate radical, a kind of in the trifluoromethanesulfonic acid root.