CN102959066A

CN102959066A - Hydraulic oil composition

Info

Publication number: CN102959066A
Application number: CN2011800315186A
Authority: CN
Inventors: 高桥一聪; 设乐裕治
Original assignee: JX Nippon Oil and Energy Corp
Current assignee: Eneos Corp
Priority date: 2010-06-25
Filing date: 2011-02-24
Publication date: 2013-03-06
Also published as: WO2011161986A1; JPWO2011161986A1; JP5769707B2

Abstract

Disclosed is a hydraulic oil which has excellent stick-slip suppressing properties and oil-water separation properties. The disclosed hydraulic oil includes, in a lubricant base oil, not more than 0.01-10 mass%, with reference to the total amount of lubricating oil, of a glycerol stearate, preferably glycerol mono-isostearate, and 0.0001-0.1 mass%, with reference to the total amount of lubricating oil, of a polyalkylene glycol having a weight-average molecular weight of 5,000-20,000; and at 40 DEG C the hydraulic oil has a dynamic viscosity of 10-600mm2/s and a viscosity index of at least 80.

Description

Hydraulic oil composition

Technical field

The present invention relates to have the hydraulic oil composition of function and the excellent oily water separation performance of the sliding part generation stick-slip that suppresses hydro-cylinder.

Background technology

Fork truck, construction implement, various vibroshock or injection moulding machine, work mechanism, stamping machine, forging and pressing punch process etc. need that use can be with the pressurization energy transformation of the hydro-pump hydraulic efficiency system as kinetic energy (power energy) more in the system of high-power energy.In the cylinder section of this hydraulic efficiency system, metal each other or the various parts of metal and resin, elastomeric material and so on slide, be lubricated with hydraulic oil in order to carry out these round and smooth slips.In this case, if sliding velocity is extremely slow, then the formation scarce capacity of oil film, cause breaking of oil film and cause static friction coefficient to become more remarkable when large than kinetic friction coefficient, produce stick-slip at slipping plane, produce noise, vibration.It is that 0.01m/s occurs when following that this stick-slip particularly is easy in sliding velocity, in addition, in parts, particularly the slip of metal and elastomeric material is that the limit repeats to condense between parts and the sliding edge motion of advancing, so the generation of the increase of its frictional coefficient, vibration is compared greatly than intermetallic slip.

In order to suppress the generation of this stick-slip, only the oil film retention of base oil is inadequate, has usually added the effect high friction regulator of chemisorption in slide unit and formation lubricating film coated.For example, use the metal series organic compounds such as molybdenum in the lubricating oil that oil engine is used, thereby reduced frictional coefficient, but when it is applicable to hydraulic oil, exist metal ingredient to become to be insoluble to lubricating oil mud, action part is caused detrimentally affect, cause the problem of the lost of life and so on of machine itself.

In addition, also exist slipper to immerse easily rainwater, emulsification of lubricant and make lubricating function that deteriorated and so on problem occur in arm oil cylinder (arm cylinder) section of fork truck, construction implement or the various vibroshocks of outdoor application.

Need to prove, friction regulator is generally brought into play its effect by be adsorbed on the metallic surface when forming lubricating film coated, but has following character: cause the oily water separation performance of lubricating oil to reduce easy emulsification when water is sneaked into owing to adsorption group has polarity.

Work mechanism polycarboxylate, that have anti-stick-slip and have an excellent oil-water separativeness that the applicant has proposed to contain in the lubricant base 0.05 ~ 10 quality % is with lubricating oil composition (patent documentation 1).But this lubricating oil has following problem: in the slow hydro-cylinder of sliding velocity, a little less than the absorption of friction regulator to the metallic surface, therefore can't suppress fully the generation of stick-slip.

In addition, the inventor etc. be for the province that realizes hydraulic efficiency system can quantize, and have proposed following hydraulic oil, and it is take mineral oil and/or poly-alpha-olefin as base oil, and the kinematic viscosity under 40 ℃ is 10 ~ 600mm ²/ s, viscosity index are 140 ~ 200, the reduced viscosity rate during the high temperature high-shear is that reduced viscosity rate below 0.5%, in the shear stability test is below 0.5%, compounding the olefin copolymer of molecular weight below 5000 and the Vinlub of 0.01 ~ 10 % by weight (patent documentation 2) of 0.1 ~ 10 % by weight.But stick-slip generating function or the oil-water separativeness of the sliding part of the inhibition hydro-cylinder of this hydraulic oil are all insufficient.

The prior art document

Patent documentation

Patent documentation 1: TOHKEMY 2009-221330 communique

Patent documentation 2: TOHKEMY 2008-127426 communique

Summary of the invention

The problem that invention will solve

The problem that the present invention will solve provides a kind of hydraulic oil composition that has high stick-slip generation rejection and have excellent oily water separation performance.

For the scheme of dealing with problems

The inventor conducts in-depth research in order to solve above-mentioned problem, found that thrilling is to contain Vinlub and a small amount of polyalkylene glycol by making lubricant base, can take into account stick-slip rejection and oily water separation performance, thereby expect the present invention.

Namely, hydraulic oil composition of the present invention in lubricant base, contain by lubricating oil total amount benchmark count 0.01 ~ 10 quality % Vinlub and by lubricating oil total amount benchmark count 0.0001 ~ 0.1 quality %, weight-average molecular weight is 5000 ~ 20000 polyalkylene glycol, the kinematic viscosity of this hydraulic oil composition under 40 ℃ is 10 ~ 600mm ²/ s, viscosity index is more than 80.

In addition, preferably, as above-mentioned Vinlub, use glycerine list isostearate, as polyalkylene glycol, use PEP-101, wherein, the polymerization molar ratio (propylene oxide/oxyethane) of oxyethane and propylene oxide is 0.5 ~ 3.5.

The effect of invention

Hydraulic oil of the present invention can play to have high stick-slip generation rejection and has excellent this significant effect of oily water separation performance.

Embodiment

Below, be described in detail for embodiments of the present invention.

Hydraulic oil composition of the present invention is to contain the Vinlub of specified quantitative and the composition of polyalkylene glycol in lubricant base, and the kinematic viscosity under its 40 ℃ is 10 ~ 600mm ²/ s, viscosity index are more than 80.Kinematic viscosity under these 40 ℃ is preferably 10 ~ 460mm ²/ s, more preferably 10 ~ 320mm ²/ s.Kinematic viscosity under 40 ℃ is lower than 10mm ²During/s, the abundant oil film that can't form on the other hand, surpasses 600mm ²During/s, viscous resistance becomes, and energy excessive, that hydraulic efficiency system is used increases.And then aforementioned viscosity index is preferably more than 90, and more preferably more than 100, viscosity index is preferably more high better, but namely is being sufficient below 250 usually.Viscosity index is lower than at 80 o'clock, and according to the difference of use temperature, the running ability during starting reduces.

(lubricant base)

The employed base oil of hydraulic oil of the present invention is this lubricated main body of oil, so long as the base oil that usually uses as lubricant base gets final product, can use any of mineral oil, synthetic oil or their mixture.

As the physical property of this lubricant base, kinematic viscosity, pour point, flash-point etc. are important, and the kinematic viscosity under 40 ℃ is preferably 10 ~ 600mm ²/ s, more preferably 20 ~ 300mm ²/ s.Pour point is preferably below-5 ℃, more preferably-10 ℃ below.And then viscosity index is preferably more than 80, more preferably more than 100.

These physical property are large on the impact as the physical property of the hydraulic oil of end article, need to obtain the desired physical property of final lubricating oil product-use.Lubricant base be account for more than 80% of hydraulic oil, according to circumstances be the main component that accounts for more than 90%, therefore preferably have the physical property close with the physical property of desirable lubricating oil.

In addition, if the hydraulic oil flash more than 250 ℃, is not hazardous material then, belong to the flammable liquid class aspect fire service law, be easy to process.Therefore, be more than 250 ℃ as the lubricant base of this lubricated main body of oil also preferred its flash-point.

In the situation of the mixture of various kinds of lubricating oil base oil, so long as satisfy above-mentioned physical property as this mixture, even departing from the scope of above-mentioned physical property, also can use by the single base oil before then mixing.

Be lubricant base as mineral oil, can list and crude oil to be carried out air distillation or further to carry out underpressure distillation and the distilled oil that obtains is made with extra care the lubricating oil distillate that forms by various process for refining.Process for refining has hydrofinishing, solvent extraction, solvent dewaxing, hydrodewaxed, sulfuric acid scrubbing, clay treatment etc., and they with suitable sequential combination and process, can be obtained base oil of the present invention.The mixture of the combination by different technique of different crude oil or distilled oil, multiple treated oil that the proterties that order obtains is different also is useful.No matter by either method, after the mode that resulting base oil satisfies aforementioned viscosity, flash-point, pour point and viscosity index with proterties is adjusted, can preferably use.

Be lubricant base as synthetic oil, preferably use the base material of stability to hydrolysis excellence, such as listing poly-alpha-olefin, polybutene, the polyolefine such as multipolymer of various alkene more than 2 kinds, polyester, polyalkylene glycol, alkylbenzene, alkylnaphthalene etc.Wherein, poly-alpha-olefin is from the property obtained, cost aspect, viscosity characteristics, oxidative stability, consider it is preferred with the suitability aspect of system component.In the poly-alpha-olefin, it is preferred that the polymkeric substance of 1-laurylene, 1-decene etc. is considered from the cost aspect.

For lubricant base, the synthetic oil shown in the example can be used separately or mix more than 2 kinds and use.And then, also can use with aforementioned mineral oil.

When use comprises synthetic oil and is mixture lubricant base, the various kinds of lubricating oil base oil, as long as this base oil mixture satisfies above-mentioned physical property, even departing from the scope of described physical property, also can use by the single base oil before then mixing.Therefore, single synthetic oil is that base oil not necessarily needs to satisfy above-mentioned physical property, but preferred in the scope of above-mentioned physical property.

(Vinlub)

Comprise iso stearic acid of glycerine ester in the Vinlub of the present invention.That is, be the ester of glycerine (glycerol) and stearic acid or Unimac 5680, this ester has monoesters, diester, three esters, and then, diester, three esters also have the complex ester of stearic acid and Unimac 5680, in the present invention, can use the multiple mixture of their any or they.

This Vinlub is because carbochain is saturated, so lubricating film coated chemically can arrange regularly, thereby the oiliness effect of lipophilic group is got a promotion.Need to prove, in the present invention, the preferred glycerine list isostearate that the solvability to base oil is promoted by having side chain that uses.

The content of this Vinlub is counted 0.01 ~ 10 quality % by lubricating oil total amount benchmark, is preferably 0.02 ~ 1 quality %.When content is lower than 0.01 quality %, can't obtain sufficient stick-slip inhibition, and when surpassing 10 quality %, not only effect reaches capacity, also can produce the problem such as separate out.

(polyalkylene glycol)

As polyalkylene glycol of the present invention, can use the alkylene oxide of carbon number 2 ~ 4, particularly, can use any of one kind or two or more ring-opening polymerization polymer in oxyethane, propylene oxide, butylene oxide ring and the different butylene oxide ring or multipolymer, be preferably PEP-101, wherein the polymerization molar ratio (propylene oxide/oxyethane) of optimization ethylene oxide and propylene oxide is 0.5 ~ 3.5, more preferably 1.0 ~ 3.0.

In addition, the weight-average molecular weight of this polyalkylene glycol (MW) is 5000 ~ 20000, is preferably 6000 ~ 15000, more preferably 8000 ~ 12000.When weight-average molecular weight (MW) departs from 5000 ~ 20000 scope, can't guarantee fully demulsification performance, the oily water separation performance when water is sneaked into is not enough.

The content of this polyalkylene glycol is counted 0.0001 ~ 0.1 quality % by lubricating oil total amount benchmark, is preferably 0.001 ~ 0.05 quality %.When content is lower than 0.0001 quality %, can't obtain sufficient oily water separation performance, and when surpassing 0.1 quality %, the oily water separation performance can worsen also.

Suitably compounding viscosity index improver, pour point depressant, antioxidant, rust-preventive agent, anti-wear agent, extreme pressure agent, defoamer, metal passivator etc. in the lubricating oil of the present invention.

Particularly, viscosity index improver is owing to can make lubricating oil high viscosity index (HVI) Hua He province quantize, and therefore preferred the interpolation for example can use PMA polymkeric substance, alkene to overlap thing, ethylene-alpha-olefin polymers.Its addition is preferably 0.1 ~ 10 quality %.

The preferred a small amount of interpolation polymkeric substance that namely tell on, molecular weight 400,000 ~ 600,000 of pour point depressant, particularly preferably PMA polymkeric substance, polybutene, its addition is preferably the scope of 0.05 ~ 0.5 quality %, more preferably the scope of 0.05 ~ 0.3 quality %.

In addition, antioxidant suitably compounding lubricating oil with in normally used phenol be that antioxidant, amine are antioxidant etc.As rust-preventive agent, the suitable common known additive such as the metal-salt of compounding Ca, Ba etc. (sulfonate etc.), nonionic based compound (sorbitol ester, nonylplenyl ether class etc.), succsinic acid part ester.

And then, as anti-wear agent/extreme pressure agent, can list sulphur system (disulphide, olefine sulfide etc.), phosphorus system (Tritolyl Phosphate, dialkyl dithiophosphate etc.), organo-metallic system (zinc dialkyl dithiophosphate etc.) etc.Fully antifriction consumption, extreme pressure and suitably compounding in economic aspect also preferred scope can given.As defoamer, can use silicon-type, PMA polymer system etc., as metal passivator, can use benzotriazole, thiadiazoles etc.

Embodiment

Below, the present invention is described in detail to enumerate embodiment, but the present invention is not limited to following embodiment.

As lubricant base, used and had mineral oil and synthetic oil (poly-alpha-olefin: the mixture of INEOS Group Limited, DURASYN 168 and DURASYN 180, fatty acid ester: Croda Japan KK, EMKARATE 1700) proterties shown in the table 1, that implemented solvent dewaxing after the hydrofinishing.

[table 1]

	Mineral oil	Poly-alpha-olefin	Fatty acid ester
				Density, g/cm ³	0.868	0.836	0.971
40 ° of C kinematic viscosity, mm ²/s	32.3	63.69	18.8
				100 ° of C kinematic viscosity, mm ²/s	5.50	9.83	4.12
Viscosity index	107	138	122

Used glycerine list isostearate as Vinlub, in order to compare, used polycarbonate (Rhein Chemie Corporation, RC8100), sulfuration ester (Dainippon Ink And Chenicals, Inc., ダイルー Block FS-150), the friction regulator such as molybdenum dithiocarbamate (ADEKA Corporation, Sakura-Lube 165).

Polyalkylene glycol has used following 4 kinds.

(1) EO-PO copolymer A: PEP-101; Weight-average molecular weight=10000, molar ratio=1:2 of EO:PO

(2) PO-BO multipolymer: propylene oxide-butylene oxide ring multipolymer; Weight-average molecular weight=8000, molar ratio=1:1.5 of EO:PO

(3) EO-PO multipolymer B: PEP-101; Weight-average molecular weight=25000, molar ratio=1:4 of EO:PO

(4) EO-PO multipolymer C: PEP-101; Weight-average molecular weight=2000, molar ratio=1:2 of EO:PO

For trial-production oil, measure lubricant base, the additive shown in the table 2 of specified amount in the stainless steel container made, heat to 60 ℃, additive is dissolved equably.Need to prove, in order to give the fundamental property as lubricating oil, as other additive, compounding 0.5 quality % antioxidant, 0.5 quality % anti-wear agent are used as basic additive respectively in the base oil of whole embodiment, comparative example, thereby give fundamental property as lubricating oil (anti-oxidant etc.).

＜performance evaluation＞

For the trial-production oil that obtains thus, measured respectively the resistance to emulsion under oxidative stability under kinematic viscosity under 40 ℃ and 100 ℃ take JIS K2283 as benchmark and viscosity index, the rotating bomb oxidation test take JIS K2514 as benchmark (Rotating Bomb Oxidation Test, RBOT), take JIS K2520 as benchmark 54 ℃.In addition, carried out rub(bing)test according to following method.

Rub(bing)test: use with the LFW-1 trier of chunk (paracril)/ring (SUJ-2) as sliding material, load-carrying is made as 44N, temperature and is made as 70 ℃, sliding velocity and was made as each speed lower 5 minutes, and the sequential stages ground of pressing 0.01m/s, 0.1m/s, 0.6m/s, 1m/s increases.Frictional coefficient under each speed is used as data.In addition, when in rub(bing)test, finding noise, abnormal vibrations, will be when recorder be observed the rheological parameters' change with time of frictional coefficient the frictional coefficient part situation that sharply increases or reduce be judged as and stick-slip occurs.

These be the results are shown in table 2.

[table 2]

As shown in Table 2, for the comparative example 1 that does not add the friction regulators such as glycerine list isostearate, under the such low-speed conditions of 0.01m/s stick-slip has just occured, frictional coefficient is relatively large.On the other hand, for the embodiment 1 ~ 4 that contains glycerine list isostearate and comparative example 2,7,8,9, the frictional coefficient in these low speed fields reduces, and can be observed the stick-slip inhibition based on friction regulator.Need to prove that comparative example 5 has been owing to produced brown Shen Dian, thereby do not carry out various evaluation tests.

Embodiment 1 ~ 4 has good stick-slip rejection, oxidation-stabilized performance, oily water separation performance, and on the other hand, although comparative example 2 stick-slip rejections are high, oily water separation performance aspect is lower than embodiment 1 ~ 4.In addition, comparative example 3,4 stick-slip rejection are compared with embodiment 1 ~ 4, are in a disadvantageous position.And then the oxidative stability of comparative example 6 is poorer than embodiment, when long-time the use, may be owing to oxidative degradation produce mud, thus cause the generation of the early stage fault of the fault of hydraulic efficiency system.

Added weight-average molecular weight in the comparative example 7,8 and be 25000 or 2000 polyalkylene glycol, but can't guarantee fully demulsification performance, the oily water separation performance when water is sneaked into is not enough.And then, the addition as many as 0.5% of the polyalkylene glycol in the comparative example 9, but oil-water separativeness worsens on the contrary.

As above clear and definite, according to the present invention, by being used in combination as the Vinlub of friction regulator and the polyalkylene glycol with specific weight-average molecular weight, can bring excellent stick-slip rejection and oxidation-stabilized performance, oily water separation performance for hydraulic oil.By such low-friction coefficient, can improve the value added as the hydraulic oil of province's energy of seeking in recent years, noise-proofing, vibration proof etc.

Utilizability on the industry

It can be hydraulic efficiency system, the machinery such as the industrial equipment such as injection moulding machine, work mechanism, stamping machine, forging and pressing stamping machine of kinetic energy (power energy) with the pressurization energy transformation of hydro-pump that hydraulic oil composition of the present invention can be used as, construction implement, work mechanism, vehicle, boats and ships, the hydraulic oil of the hydraulic machine of aviation machine etc., device etc.Particularly, hydraulic oil composition of the present invention is because stick-slip generation rejection and oily water separation performance are excellent, therefore to being useful at the sliding part of the hydro-cylinder of the fork truck of outdoor application, construction implement etc. or the lubricated of arm oil cylinder sliding part of various vibroshocks.

Claims

1. hydraulic oil composition, it contains in lubricant base by lubricating oil total amount benchmark counts the Vinlub below 0.01 ~ 10 quality % and is 5000 ~ 20000 polyalkylene glycol by the weight-average molecular weight that lubricating oil total amount benchmark is counted 0.0001 ~ 0.1 quality %, and the kinematic viscosity of this hydraulic oil composition under 40 ℃ is 10 ~ 600mm ²/ s, viscosity index is more than 80.

2. hydraulic oil composition according to claim 1, wherein, Vinlub is glycerine list isostearate.

3. hydraulic oil composition according to claim 1 and 2, wherein, polyalkylene glycol is PEP-101, the polymerization molar ratio of oxyethane and propylene oxide is that propylene oxide/oxyethane is 0.5 ~ 3.5.