JP2010529240A - Improving power output in hydraulic systems - Google Patents

Abstract

  The present invention describes the use of a fluid having a VI of at least 130 to improve the output of a hydraulic system. Preferably, engine speed can be maintained at the same selected speed while using standard HM oil to deliver> 3% higher hydraulic power.

Description

  The present invention relates to increased power output in hydraulic pumps and motors achieved by the use of hydraulic fluids having high viscosity indices. The use of such fluids can increase the output of the system without modifying the hardware.

  The hydraulic system is designed to transfer energy and apply large forces under high flexibility and control. It would be desirable to build a system that efficiently converts input energy from an engine, electric motor, or other source into usable work. Fluid power can be used to cause rotational or linear motion or to store energy in an accumulator for future use. Hydraulic systems provide significantly more accurate and adjustable energy transfer means than electrical or mechanical systems. In general, hydraulic systems are reliable, efficient, cost effective and widely used in industry. The fluid power industry is constantly improving the cost effectiveness of hydraulic systems by using new mechanical components and components.

  With water and many liquids, Pascal's principle can be used in practice, where the fluid compressed in a closed vessel does not reduce the resulting pressure throughout the system. Say to transmit equally in all directions.

  Standard “HM” monograde oil is typically the choice because it is the least expensive option and since ancient times it has reliable performance without maintenance problems. In fluid powered outdoor applications that experience a wide range of temperature changes, low viscosity grade fluids are used in winter and high viscosity grade fluids are used in summer. In order to achieve good low temperature fluidity under cold start conditions, PAMA additives are blended into certain hydraulic fluids as viscosity index improvers (“HV” grade oil). It is not known that PAMA additives provide other performance benefits.

  For example, document WO20050108531 describes the use of a hydraulic fluid containing a PAMA additive to reduce the temperature rise of the hydraulic fluid under work load. However, no improvement in output is described or suggested in this document.

  Furthermore, document WO2005014762 discloses a functional fluid having improved fire resistance. This fluid can be used in a hydraulic system. However, this document does not describe the output of a system that uses such a fluid.

  Achieving higher output in a hydraulic system is typically done by selecting a larger pump or improving other hardware configurations of the unit that provides mechanical energy to the hydraulic system. However, such methods are usually associated with higher energy consumption and increased costs.

  A further general purpose is to improve the volume output. According to the prior art, these objectives are achieved by a combustion engine or electric motor with greater power. However, such methods are usually associated with higher energy consumption and increased costs and are often constrained by space or mass limitations.

  In view of the prior art, an object of the present invention is to provide a hydraulic system with increased output to facilitate increased workload and improved productivity. The increased power can be used to increase excavation force, lift, or machine speed. Furthermore, it is a general goal to improve the life and service life of hydraulic systems.

  These as well as other unspecified objects that can be easily derived or revealed from the beginning are achieved by the use of the fluid of claim 1 of the present invention.

  In particular, an improvement in the hydraulic output is achieved by the use of the fluid of claim 1 of the present invention. Appropriate modifications of the use of the invention are described in the dependent claims.

  Using a fluid with a VI of at least 130 results in an unexpected increase in pump hydraulic output. As a result of the increased output from the pump, the output from the hydraulic motor (cylinder or rotary motor) increases.

  The hydraulic fluids of the present invention exhibit improved low temperature performance and a wider temperature operating range. Furthermore, hydraulic fluid provides an improvement in volume output. Furthermore, hydraulic systems that use hydraulic fluids with a VI of at least 130 exhibit improved power reduction, especially with high-load units that provide mechanical work. Thus, output invariance is improved by use of the present invention.

  The hydraulic fluids of the present invention can be sold on a cost-effective basis with fast capital recovery periods.

  It is also possible to design hydraulic systems that utilize high viscosity exponential hydraulic fluids that operate at lower pressure levels and produce equal amounts of hydraulic output with lower pump input energy. A system operating at lower pressure will have a longer component life (seal, hose, wear surface, fluid), resulting in lower fluid operating temperatures.

  The hydraulic fluids of the present invention exhibit good resistance to oxidation and are chemically very stable compared to standard HM fluids.

  The viscosity of the hydraulic fluid of the present invention can be adjusted over a wide range.

  Furthermore, the hydraulic fluid of the present invention is suitable for high pressure applications in the range of 100 to 700 bar. The hydraulic fluids of the present invention have minimal viscosity changes during operation for good shear stability.

  Furthermore, improvements in power and system productivity can be achieved without structural changes in the hydraulic system. As a result, the output of both new and old hydraulic systems can be improved at a very low cost. Such hydraulic fluid compositions are well compatible with existing elastomeric materials used in seals, bladders, and hoses, which are readily acceptable for use in existing industrial hydraulic systems.

  The hydraulic fluid used in accordance with the present invention has a viscosity index of at least 130, preferably at least 150, more preferably at least 180, and most preferably at least 200. According to a preferred embodiment of the present invention, the viscosity index ranges from 150 to 400, more preferably from 200 to 300. The viscosity index can be determined according to ASTM D2270.

  Use of the present invention improves the output of the hydraulic system. The expression “output” is energy that can be used as work and typically means what is measured and quantified in horsepower or kilowatts as output torque from a rotary hydraulic motor.

  Preferably, the fluid of the present invention is compared to the output of a system using a monograde hydraulic fluid having a VI of about 100 operating at the same pressure and temperature with the same mechanical input from the engine or electric motor. Effective to increase the output of the hydraulic system by at least 3%, more preferably at least 5%, and more preferably at least 10%. Thus, although an equal amount of energy is consumed (fuel or power), a system using high VI fluid will produce more usable output in equal time periods.

In accordance with a preferred embodiment of the present invention, the volume output is increased. Preferably, the fluid of the present invention is compared to the volume output of a system using a monograde hydraulic fluid having a VI of about 100 that operates at the same pressure and temperature with the same mechanical input from the engine or electric motor. Thus, it is effective to increase the volumetric output of the hydraulic system by at least 3%, more preferably at least 5%, and more preferably at least 10%. The expression “volumetric output” means the volume provided to a hydraulic motor that can be used as work at a specific pressure differential, typically measured and quantified in m ³ or liters.

  The present invention can further provide a method for improving output invariance. Surprisingly, the power invariance can be increased even at maximum load. For example, the reduction in power after an operating time of at least 10 minutes is preferably up to 3% as measured at 90% or more of the maximum load of the unit providing mechanical energy.

  With the aforementioned improvements, the performance of the hydraulic system can be increased in a surprising way. By providing a system that is low in output and protracted, it can be used with the ultimate power of the unit that produces mechanical energy. Therefore, the predetermined work can be performed in a shorter time without requiring a change in the structure of the system. Preferably, the engine speed of the unit providing mechanical energy is maintained at a constant speed and the system delivers increased levels of fluid power.

  According to a preferred embodiment of the present invention, the hydraulic system is designed to operate at low pressure so that the output is equal to that delivered by a reference system with a hydraulic fluid having a VI of 100. Can do. Those skilled in the art can easily make such design changes. For example, in an excavator, the shovel can be changed. By using even lower pressures, the lifetime and service life of hydraulic systems can be improved in surprising ways.

  According to a preferred embodiment of the present invention, the hydraulic system can show an improvement in the ratio of hydraulic output to input, where the output / input ratio is a reference system using a hydraulic fluid having a VI of 100. Preferably at least 3%, more preferably at least 5% improvement compared to that delivered by.

  The viscosity of the hydraulic fluid of the present invention can be widely adapted according to the requirements of the hydraulic pump / motor manufacturer. For example, ISO VG 15, 22, 32, 46, 68, 100, 150 fluid grades can be achieved.

Preferably, kinematic viscosity 40 ° C. by ASTM D 445 ^{is, 15mm 2 / s~150mm 2 / s} , preferably from 28mm ² / s~110mm ² / s.

  For use in the present invention, suitable hydraulic fluids are NFPA (National Fluid Power Association) multi-grate fluids as defined by NFPA T2.13.13-2002, such as double, triple, quadra and / or pentagrade fluids. .

  Suitable fluids include at least mineral oil and / or synthetic oil.

  Mineral oils are substantially known and are commercially available. Mineral oil is generally obtained from petroleum or crude oil by distillation and / or refining and optionally further refining and processing methods, in particular the high-boiling fraction of crude oil or petroleum falls under the concept of mineral oil. In general, the boiling point of mineral oil is 5000 Pa, higher than 200 ° C, preferably higher than 300 ° C. Production by low temperature distillation of shale oil, coking of hard coal, distillation of lignite under air exclusion and hydrogenation of hard or lignite is possible as well. Slightly, mineral oils are also made from raw materials of plant origin (eg jojoba, rapeseed (canola), sunflower and soy oil) or from animal sources (eg tallow or cow leg oil). Thus, mineral oils exhibit different amounts of aromatic, cyclic, branched and straight chain hydrocarbons in each case, depending on the origin.

  In general, paraffinic, naphthenic and aromatic fractions in crude oil or mineral oil are distinguished, where the term paraffinic fraction refers to long chain or highly branched isoalkanes, where naphthenic fractions refer to cycloalkanes. To express. Furthermore, the mineral oil in each case contains n-alkanes, low-branched isoalkanes, so-called monomethyl-branched paraffins, and heteroatoms responsible for polarity, in particular O, N and / or S, depending on the origin and treatment. The various fractions of compounds with are shown. However, attribution is difficult. The reason is that individual alkane molecules can have both long chain branches and cycloalkane residues as well as aromatic components. For the purposes of the present invention, classification can be performed according to DIN 51378. The polar component can also be determined according to ASTM D2007.

  The proportion of n-alkane in the preferred mineral oil is less than 3% by weight and the proportion of O, N and / or S-containing compounds is less than 6% by weight. The proportion of aromatic compound and monomethyl branched paraffin is generally in the range from 0 to 40% by weight in each case. According to one interesting aspect, the mineral oil mainly comprises naphthenic and paraffinic alkanes, which generally have more than 13, preferably more than 18 and particularly preferably more than 20 carbon atoms. The proportion of these compounds is generally at least 60% by weight, preferably at least 80% by weight, and is not intended to be limited thereto. Suitable mineral oils are in each case from 0.5 to 30% by weight aromatic component, from 15 to 40% by weight naphthenic component, from 35 to 80% by weight paraffinic component, up to 3%, based on the total weight of the mineral oil. Contains up to wt% n-alkane and 0.05-5 wt% polar component.

Analysis of a particularly suitable mineral oil, performed using traditional methods such as urea dewaxing and liquid chromatography on silica gel, shows for example the following components (where percentages are based on the total mass of the relevant mineral oil) ):
N-alkane having about 18-31 C atoms: 0.7-1.0%,
Low-branched alkane having 18-31 C atoms: 1.0-8.0%,
Aromatic compounds having 14 to 32 C atoms: 0.4 to 10.7%,
Isoalkanes and cycloalkanes having 20 to 32 C atoms: 60.7-82.4%,
Polar compound: 0.1-0.8%
Loss: 6.9 to 19.4%.

  Useful advice on the analysis of mineral oils, as well as a list of mineral oils with other compositions, can be found, for example, in the "Lubricants and relevant prod." Section of Ullmann's Encyclopedia of Industrial Chemistry, 5th Edition on CD-ROM, 1997. .

  Preferably, the hydraulic fluid is a mineral oil base from API Group I, II, or III. According to a preferred embodiment of the present invention, a mineral oil is used which contains at least 90% by weight of saturated material and at most about 0.03% sulfur as determined by elemental analysis. API group II oil is particularly preferred.

  API Group IV and V synthetic oils, among other materials, are organic esters such as carboxylic esters and phosphate esters; organic ethers such as silicone oils and polyalkylene glycols; and synthetic hydrocarbons, particularly polyolefins and Fischer-Tropsch ( GTL) base oil. These are mostly slightly more expensive than mineral oil, but are advantageous in terms of performance. For illustration, reference is made to 5 API class base oil types (API: American Petroleum Institute).

American Petroleum Institute (API) base oil classification

  Synthetic hydrocarbons, especially polyolefins, are well known in the art. Polyalphaolefin (PAO) is particularly suitable. These compounds can be obtained by polymerization of alkenes, especially alkenes having 3 to 12 carbon atoms, such as propene, hexene-1, octene-1, and dodecene-1. Suitable PAOs have a number average molecular weight in the range of 200-10000 g / mol, more preferably 500-5000 g / mol.

  According to a preferred embodiment of the present invention, the hydraulic fluid may comprise an oxygen-containing compound selected from the group consisting of carboxylic acid esters, polyether polyols and / or organophosphorus compounds. Preferably, the oxygen-containing compound is a carboxylic acid ester containing at least two ester groups, a diester of carboxylic acid containing 4 to 12 carbon atoms and / or an ester of a polyol. By using an oxygen-containing compound as the base stock, the fire resistance of the hydraulic fluid can be improved.

  For example, alkylaryl phosphate esters; trialkyl phosphates such as tributyl phosphate or tri-2-ethylhexyl phosphate; triaryl phosphates such as mixed isopropyl phenyl phosphate, mixed t-butyl phenyl phosphate, trixylenyl phosphate, or tricresyl phosphate Phosphorus ester fluids such as can be used as components of hydraulic fluids. Further types of organophosphorus compounds are phosphonates and phosphinates, which may contain alkyl and / or aryl substituents. Dialkyl phosphonates such as di-2-ethylhexyl phosphonate; alkyl phosphinates such as di-2-ethylhexyl phosphinate are useful. As the alkyl group in the present specification, linear or branched alkyl containing 1 to 10 carbon atoms is preferable. As the aryl group in the present specification, aryl containing 6 to 10 carbon atoms (which may be substituted with alkyl) is preferable. In particular, the hydraulic fluid may contain from 0 to 60% by weight, preferably from 5 to 50% by weight of an organophosphorus compound.

  As carboxylic acid esters, reaction products such as alcohols such as polyhydric alcohols and monohydric alcohols and fatty acids such as monocarboxylic acids and polycarboxylic acids can be used. Such a carboxylic acid ester may naturally be a partial ester.

  The carboxylic acid ester can have one carboxylic acid ester group having the formula R—COO—R, where R is independently a group containing 1 to 40 carbon atoms. Suitable ester compounds contain at least two ester groups. These compounds may be based on polycarboxylic acids having at least two acidic groups and / or polyols having at least two hydroxyl groups.

  The polycarboxylic acid residue usually has 2 to 40, preferably 4 to 24, in particular 4 to 12 carbon atoms. Useful polycarboxylic acid esters are, for example, esters of adipic acid, azelaic acid, sebacic acid, phthalic acid and / or dodecanoic acid. The alcohol component of the polycarboxylic acid compound preferably contains 1 to 20, in particular 2 to 10 carbon atoms.

  Examples of useful alcohols are methanol, ethanol, propanol, butanol, pentanol, hexanol, heptanol and octanol. In addition, oxo alcohols such as diethylene glycol, triethylene glycol, tetraethylene glycol to decamethylene glycol can be used.

  Particularly preferred compounds are esters of polycarboxylic acids with alcohols containing one hydroxyl group. Examples of these compounds are described in Ullmanns Encyclopaedier der Technischen Chemie, third edition, vol. 15, page 287-292, Urban & Schwarzenber (1964)).

  Polyols useful for obtaining ester compounds containing at least two ester groups usually contain 2 to 40, preferably 4 to 22 carbon atoms. Examples are neopentyl glycol, diethylene glycol, dipropylene glycol, 2,2-dimethyl-3-hydroxypropyl-2 ′, 2′-dimethyl-3′-hydroxypropionate, glycerol, trimethylolethane, trimethanolpropane, Trimethylol nonane, ditrimethylolpropane, pentaerythritol, sorbitol, mannitol and dipentaerythritol. The carboxylic acid component of the polyester may contain 1 to 40, preferably 2 to 24 carbon atoms. Examples are linear or branched saturated fatty acids such as formic acid, acetic acid, propionic acid, octanoic acid, caproic acid, enanthic acid, caprylic acid, pelargonic acid, capric acid, undecanoic acid, lauric acid, tridecanoic acid, myristic acid, pentadecanoic acid , Palmitic acid, heptadecanoic acid, stearic acid, nonadecanoic acid, arachidic acid, behenic acid, isomyristic acid, isopalmitic acid, isostearic acid, 2,2-dimethylbutanoic acid, 2,2-dimethylpentanoic acid, 2,2- Dimethyloctanoic acid, 2-ethyl-2,3,3-trimethylbutanoic acid, 2,2,3,4-tetramethylpentanoic acid, 2,5,5-trimethyl-2-t-butylhexanoic acid, 2,3 , 3-Trimethyl-2-ethylbutanoic acid, 2,3-dimethyl-2-isopropylbutanoic acid, 2-ethylhexa Acids, 3,5,5-trimethylhexanoic acid; linear or branched unsaturated fatty acids such as linoleic acid, linolenic acid, 9 octadecenoic acid, undecenoic acid, elaidic acid, cetreic acid, erucic acid, brassic acid, and various animals It is a commercial grade oleic acid obtained from natural fat or vegetable oil sources. Mixtures of fatty acids such as tall oil fatty acids can be used.

  Particularly useful compounds containing at least two ester groups are, for example, neopentyl glycol taleate, neopentyl glycol dioleate, propylene glycol taleate, propylene glycol dioleate, diethylene glycol taleate, and diethylene glycol dioleate.

  Many of these compounds are available from Inolex Chemical Co. Under the trademark Lexolube 2G-214, Cognis Corp. Under the trademark ProEco 2965 under the trademark Uniqema Corp. Is commercially available under the trademarks Priolube 1430 and Priolube 1446 from Georgia, and under the trademarks Xtolube 1301 and Xtolube 1320 from Georgia Pacific.

  In addition, ethers are useful as components of hydraulic fluids. Preferably, a polyether polyol is used as a component of the hydraulic fluid of the present invention. These compounds are well known. Examples are polyalkylene glycols such as polyethylene glycol, polypropylene glycol and polybutylene glycol. The polyalkylene glycol can be based on a mixture of alkylene oxides. These compounds preferably contain 1 to 40 alkylene oxide units, more preferably 5 to 30 alkylene oxide units. Polybutylene glycol is a suitable compound for anhydrous fluids. The polyether polyols can contain further groups such as, for example, alkylene or arylene groups containing 1 to 40, in particular 2 to 22 carbon atoms.

  According to another aspect of the invention, the hydraulic fluid comprises polyalphaolefin (PAO), carboxylic acid ester (diester or polyol ester), vegetable ester, phosphate ester (trialkyl, triaryl, or Synthetic base stock base comprising alkylaryl phosphate) and / or polyalkylene glycol (PAG). Preferred synthetic base stocks are API Group IV and / or Group V oils.

  Preferably, the hydraulic fluid can be obtained by mixing at least two components. At least one of the components must be a base oil. The expression base oil includes mineral oils and / or synthetic oils based on hydraulic fluids as described above. Preferably, the hydraulic fluid comprises at least 60% by weight base oil. Preferably, at least one of the components may have a viscosity index of 120 or less. According to a preferred embodiment, the hydraulic fluid may comprise at least 60% by weight of at least one component having a viscosity index of 120 or less.

  In particular, a polymer viscosity index improver can be used as a component of the hydraulic fluid. Viscosity index improvers are well known and are disclosed, for example, in Ullmann's Encyclopedia of Industrial Chemistry, 5th Edition on CD-ROM, 1997.

  Suitable polymers useful as VI improvers include units derived from alkyl esters having at least one ethylenically unsaturated group. These polymers are well known in the art. Suitable polymers can be obtained in particular by polymerizing (meth) acrylates, maleates and fumarate. The term (meth) acrylate includes methacrylate and acrylate and mixtures of both. These monomers are well known in the art. Alkyl residues can be linear, cyclic, or branched.

[式中、Ｒは、水素またはメチルであり、Ｒ¹は、１〜６個、特に１〜５個、好ましくは１〜３個の炭素原子を有する直鎖もしくは分岐アルキルを意味し、Ｒ²およびＲ³は、独立して、水素または式−ＣＯＯＲ’の基であり、ここでＲ’は、水素または１〜６個の炭素原子を有するアルキル基を意味する]の１以上のエチレン性不飽和エステル化合物を含む。 The mixture for obtaining a suitable polymer comprising units derived from an alkyl ester is 0 to 100% by weight, preferably 0.5 to 90% by weight, in particular 1 to 80% by weight, based on the total weight of the monomer mixture, Preferably 1-30% by weight, more preferably 2-20% by weight of formula (I)

[Wherein R is hydrogen or methyl, R ¹ represents straight-chain or branched alkyl having 1 to 6, in particular 1 to 5, preferably 1 to 3 carbon atoms, R ² And R ³ is independently hydrogen or a group of formula —COOR ′, wherein R ′ represents hydrogen or an alkyl group having 1 to 6 carbon atoms]. Contains saturated ester compounds.

  Examples of component (a) are in particular (meth) acrylates derived from saturated alcohols, fumarate and maleates such as methyl (meth) acrylate, ethyl (meth) acrylate, n-propyl (meth) acrylate, isopropyl (meth) Acrylate, n-butyl (meth) acrylate, tert-butyl (meth) acrylate, pentyl (meth) acrylate and hexyl (meth) acrylate; cycloalkyl (meth) acrylates such as cyclopentyl (meth) acrylate.

[式中、Ｒは、水素もしくはメチルであり、Ｒ⁴は、７〜４０個、特に１０〜３０個、好ましくは１２〜２４個の炭素原子を有する直鎖もしくは分岐アルキル残基を意味し、Ｒ⁵およびＲ⁶は独立して、水素または式−ＣＯＯＲ"の基であり、ここで、Ｒ"は水素または７〜４０個、特に１０〜３０、好ましくは１２〜２４個の炭素原子を有するアルキル基を意味する]の１以上のエチレン性不飽和エステル化合物を含む。 Furthermore, the monomer composition for obtaining the polymer containing the unit derived from the alkyl ester is 0 to 100% by mass, preferably 10 to 99% by mass, particularly 20 to 95% by mass, further based on the total mass of the monomer mixture. Preferably 30 to 85% by weight of formula (II)

[Wherein R is hydrogen or methyl, R ⁴ represents a linear or branched alkyl residue having 7 to 40, in particular 10 to 30, preferably 12 to 24 carbon atoms; R ⁵ and R ⁶ are independently hydrogen or a radical of the formula —COOR ″, where R ″ has hydrogen or 7 to 40, in particular 10 to 30, preferably 12 to 24 carbon atoms. Meaning one or more ethylenically unsaturated ester compounds.

These include (meth) acrylates derived from saturated alcohols, fumarate and maleates such as 2-ethylhexyl (meth) acrylate, heptyl (meth) acrylate, 2-tert-butylheptyl (meth) acrylate, octyl (meth) acrylate, 3 -Isopropylheptyl (meth) acrylate, nonyl (meth) acrylate, decyl (meth) acrylate, undecyl (meth) acrylate, 5-methylundecyl (meth) acrylate, dodecyl (meth) acrylate, 2-methyldodecyl (meth) acrylate , Tridecyl (meth) acrylate, 5-methyltridecyl (meth) acrylate, tetradecyl (meth) acrylate, pentadecyl (meth) acrylate, 2-methylhexadecyl (meth) acrylate Heptadecyl (meth) acrylate, 5-isopropylheptadecyl (meth) acrylate, 4-tert-butyloctadecyl (meth) acrylate, 5-ethyloctadecyl (meth) acrylate, 3-isopropyloctadecyl (meth) acrylate, octadecyl (meta ) Acrylate, nonadecyl (meth) acrylate, eicosyl (meth) acrylate, cetyl eicosyl (meth) acrylate, stearyl eicosyl (meth) acrylate, docosyl (meth) acrylate, and / or eicosyl tetratriacontyl (meth) acrylate ;
Cycloalkyl (meth) acrylates such as 3-vinylcyclohexyl (meth) acrylate, cyclohexyl (meth) acrylate, bornyl (meth) acrylate, 2,4,5-tri-t-butyl-3-vinylcyclohexyl (meth) acrylate, 2,3,4,5-tetra-t-butylcyclohexyl (meth) acrylate; and the corresponding fumarate and maleate are included.

  An ester compound having a long-chain alcohol residue, in particular component (b), can be obtained, for example, by reacting (meth) acrylate, fumarate, maleate and / or the corresponding acid with a long-chain aliphatic alcohol. In general, a mixture of esters such as (meth) acrylates with different long chain alcohol residues is generally obtained as a result. These aliphatic alcohols include, in particular, Oxo Alcohol (R) 7911 and Oxo Alcohol (R) 7900, Oxo Alcohol (R) 1100 (Monsanto); Alphanol (R) 79 (ICI); Nafol (R) Trademark) 1620, Alfol (R) 610 and Alfol (R) 810 (Sasol); Epal (R) 610 and Epal (R) 810 (Ethyl Corporation); Linevol (R) 79, Linevol (R) ) 911 and Dobanol (R) 25L (Shell AG); Lial 125 (Sasol); Dehydad (R) and Dehydad (R) and orol (registered trademark) (Cognis), and the like.

Of the ethylenically unsaturated ester compounds, (meth) acrylates are particularly preferred over maleates and fumarate. That is, R ² , R ³ , R ⁵ , R ⁶ in formulas (I) and (II) represent hydrogen in a particularly preferred embodiment.

  In a particular embodiment of the invention, it is preferred to use a mixture of ethylenically unsaturated ester compounds of the formula (II), which mixture has at least one (meta) having 7 to 15 carbon atoms in the alcohol group. ) Acrylate, and at least one (meth) acrylate having 16 to 30 carbon atoms in the alcohol group. The proportion of (meth) acrylate having 7 to 15 carbon atoms in the alcohol group is preferably in the range of 20 to 95% by mass with respect to the mass of the monomer composition for producing the polymer. The proportion of (meth) acrylate having 16 to 30 carbon atoms in the alcohol group is preferably from 0.5 to the mass of the monomer composition for producing a polymer containing units derived from an alkyl ester. The range is 60 masses. The mass ratio of (meth) acrylate having 7 to 15 carbon atoms in the alcohol group and (meth) acrylate having 16 to 30 carbon atoms in the alcohol group is preferably 10: 1 to 1:10. More preferably, it is the range of 5: 1 to 1.5: 1.

  Component (c) comprises in particular an ethylenically unsaturated monomer which can be copolymerized with the ethylenically unsaturated ester compound of formula (I) and / or (II).

[式中、Ｒｌ^*およびＲ２^*は、独立して、水素、ハロゲン、ＣＮ、１〜２０個、好ましくは１〜６個、そして特に好ましくは１〜４個の炭素原子を有する直鎖もしくは分岐アルキル基（１〜（２ｎ＋ｌ）個のハロゲン原子で置換することができ、ここでｎは、アルキル基（たとえばＣＦ３）の炭素原子の数である）、２〜１０個、好ましくは２〜６個、そして特に好ましくは２〜４個の炭素原子を有するα，β−不飽和直鎖もしくは分岐アルケニルまたはアルキニル基（１〜（２ｎ−ｌ）個のハロゲン原子、好ましくは塩素で置換することができ、ここでｎは、アルキル基、たとえばＣＨ₂＝ＣＣｌ−の炭素原子の数である）、３〜８個の炭素原子を有するシクロアルキル基（１〜（２ｎ−ｌ）個のハロゲン原子、好ましくは塩素で置換することができ、ここでｎは、シクロアルキル基の炭素原子の数である）；Ｃ（＝Ｙ^*）Ｒ５^*、Ｃ（＝Ｙ^*）ＮＲ^6*Ｒ^7*、Ｙ^*Ｃ（＝Ｙ^*）Ｒ^5*、ＳＯＲ^5*、ＳＯ₂Ｒ^5*、ＯＳＯ₂Ｒ^5*、ＮＲ^8*ＳＯ₂Ｒ^5*、ＰＲ^5* ₂、Ｐ（＝Ｙ^*）Ｒ^5* ₂、Ｙ^*ＰＲ^5* ₂、Ｙ^*Ｐ（＝Ｙ^*）Ｒ^5* ₂、ＮＲ^8* ₂［追加のＲ^8*、アリール、またはヘテロシクリル基で四級化することができ、ここで、Ｙ^*は、ＮＲ^8*、ＳまたはＯ、好ましくはＯであり得；Ｒ^5*は、１〜２０個の炭素原子を有するアルキル基、１〜２０個の炭素原子を有するアルキルチオ基、ＯＲ¹⁵（Ｒ¹⁵は、水素もしくはアルカリ金属である）、１〜２０個の炭素原子を有するアルコキシ、アリールオキシまたはヘテロサイクリルオキシであり；Ｒ^6*およびＲ^7*は、独立して、水素もしくは１〜２０個の炭素原子を有するアルキル基であるか、またはＲ^6*およびＲ^7*は一緒になって、２〜７個、好ましくは２〜５個の炭素原子を有するアルキレン基を形成することができ、この場合、これらは３〜８員環、好ましくは３〜６員環を形成し、Ｒ^8*は、１〜２０個の炭素原子を有する直鎖もしくは分岐アルキルまたはアリール基である］からなる群から選択され；
Ｒ３^*およびＲ４^*は独立して、水素、ハロゲン（好ましくはフッ素または塩素）、１〜６個の炭素原子を有するアルキル基およびＣＯＯＲ^9*（式中、Ｒ^9*は水素、アルカリ金属もしくは１〜４０個の炭素原子を有するアルキル基である）からなる群から選択されるか、またはＲ^1*およびＲ^3*は一緒になって式（ＣＨ₂）_nの基を形成することができ、この基は、１−２ｎ’個のハロゲン原子もしくはＣ₁−Ｃ₄アルキル基により置換することができるか、または式Ｃ（＝Ｏ）−Ｙ^*−Ｃ（＝Ｏ）（式中、ｎ’は２〜６、好ましくは３または４であり、Ｙ^*は前記定義のとおりである）の基を形成することができ；残基Ｒ^1*、Ｒ^2*、Ｒ^3*およびＲ^4*のうちの少なくとも２つは水素またはハロゲンである]。 Comonomers corresponding to the following formula are particularly suitable for the polymerization according to the invention:

[Wherein Rl ^* and R2 ^* are independently hydrogen, halogen, CN, 1-20, preferably 1-6, and particularly preferably 1-4 straight or branched carbon atoms. An alkyl group (which can be substituted with 1 to (2n + 1) halogen atoms, where n is the number of carbon atoms in the alkyl group (eg CF3)), 2 to 10, preferably 2 to 6 And particularly preferably an α, β-unsaturated linear or branched alkenyl or alkynyl group having 2 to 4 carbon atoms (1 to (2n-1) halogen atoms, preferably chlorine can be substituted. Where n is an alkyl group, for example the number of carbon atoms of CH ₂ ═CCl—, a cycloalkyl group having 3 to 8 carbon atoms (1 to (2n−1) halogen atoms, preferably Replace with chlorine It can be, where n is the number of carbon atoms of a cycloalkyl ^{group); C (= Y *)} R5 *, C (= Y *) NR 6 * R 7 *, Y * C (= Y *) ^{R 5 *, SOR 5 *,} SO 2 R 5 *, OSO 2 R 5 *, NR 8 * SO 2 R 5 *, PR 5 * 2, P (= Y *) R 5 * 2, Y * PR 5 * ₂ , Y ^* P (= Y ^* ) R ^{5 *} ₂ , NR ^{8 *} ₂ [can be quaternized with an additional R ^{8 *} , aryl, or heterocyclyl group, where Y ^* is NR ^{8 *} , S or O, preferably O; R ^{5 *} is an alkyl group having 1 to 20 carbon atoms, an alkylthio group having 1 to 20 carbon atoms, OR ¹⁵ (R ¹⁵ is hydrogen or an alkali metal), 1-20 alkoxy having carbon atoms, aryl oxy or heterocyclyl-oxy; R 6 ^* and R ^{7 *} are independently hydrogen or 1 Or an alkyl group having 20 carbon atoms, or R ^{6 *} and R ^{7 *} together, 2-7, preferably to form an alkylene group having 2 to 5 carbon atoms In which case they form a 3-8 membered ring, preferably a 3-6 membered ring, and R ^{8 *} is a linear or branched alkyl or aryl group having 1-20 carbon atoms] Selected from the group consisting of:
R3 ^* and R4 ^* are independently hydrogen, halogen (preferably fluorine or chlorine), an alkyl group having 1 to 6 carbon atoms and COOR ^{9 *} (wherein R ^{9 *} is hydrogen, alkali metal or 1 R ^{1 *} and R ^{3 *} can be taken together to form a group of formula (CH ₂ ) _n , which is an alkyl group having ˜40 carbon atoms), This group can be substituted by 1-2n ′ halogen atoms or C ₁ -C ₄ alkyl groups, or it can be represented by the formula C (═O) —Y ^* —C (═O) (where n ′ Can be a group of 2-6, preferably 3 or 4, and Y ^* is as defined above; in the residues R ^{1 *} , R ^{2 *} , R ^{3 *} and R ^{4 *} At least two of them are hydrogen or halogen].

As comonomer, in particular, hydroxyalkyl (meth) acrylate, such as 3-hydroxypropyl (meth) acrylate, 3,4-dihydroxybutyl (meth) acrylate, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) Acrylate, 2,5-dimethyl-1,6-hexanediol (meth) acrylate, 1,10-decanediol (meth) acrylate;
Aminoalkyl (meth) acrylates and aminoalkyl (meth) acrylamides such as N- (3-dimethylaminopropyl) methacrylamide, 3-diethylaminopentyl (meth) acrylate, 3-dibutylaminohexadecyl (meth) acrylate;
Nitriles of (meth) acrylic acid and other nitrogen-containing (meth) acrylates such as N- (methacryloyloxyethyl) diisobutylketimine, N- (methacryloyloxyethyl) dihexadecylketimine, (meth) acryloylamide acetonitrile, 2-methacryloyl Oxyethyl methyl cyanamide, cyanomethyl (meth) acrylate;
Aryl (meth) acrylates, such as benzyl (meth) acrylate or phenyl (meth) acrylate (wherein in each case the acrylic residue may be unsubstituted or substituted up to 4 times) ;
Carbonyl-containing (meth) acrylates such as 2-carboxyethyl (meth) acrylate, carboxymethyl (meth) acrylate, oxazolidinylethyl (meth) acrylate, N-methacryloyloxy) formamide, acetonyl (meth) acrylate, N-methacryloyl Morpholine, N-methacryloyl-2-pyrrolidinone, N- (2-methacryloyloxyethyl) -2-pyrrolidinone, N- (3-methacryloyloxypropyl) -2-pyrrolidinone, N- (2-methacryloyloxypentadecyl (-2) -Pyrrolidinone, N- (3-methacryloyloxyheptadecyl-2-pyrrolidinone;
(Meth) acrylates of ether alcohols such as tetrahydrofurfuryl (meth) acrylate, vinyloxyethoxyethyl (meth) acrylate, methoxyethoxyethyl (meth) acrylate, 1-butoxypropyl (meth) acrylate, 1-methyl- (2- Vinyloxy) ethyl (meth) acrylate, cyclohexyloxymethyl (meth) acrylate, methoxy-methoxyethyl (meth) acrylate, benzyloxymethyl (meth) acrylate, furfuryl (meth) acrylate, 2-butoxyethyl (meth) acrylate, 2- Ethoxyethoxymethyl (meth) acrylate, 2-ethoxyethyl (meth) acrylate, ethoxylated (meth) acrylate, allyloxymethyl (meth) acrylate, 1-ethoxy Butyl (meth) acrylate, methoxymethyl (meth) acrylate, 1-ethoxyethyl (meth) acrylate, ethoxymethyl (meth) acrylate;
(Meth) acrylates of halogenated alcohols such as 2,3-dibromopropyl (meth) acrylate, 4-bromophenyl (meth) acrylate, 1,3-dichloro-2-propyl (meth) acrylate, 2-bromoethyl (meth) Acrylate, 2-iodoethyl (meth) acrylate, chloromethyl (meth) acrylate;
Oxiranyl (meth) acrylate, for example 2,3-epoxybutyl (meth) acrylate, 3,4-epoxybutyl (meth) acrylate, 10,11 epoxyundecyl (meth) acrylate, 2,3-epoxycyclohexyl (meth) acrylate Oxiranyl (meth) acrylate, such as 10,11-epoxyhexadecyl (meth) acrylate, glycidyl (meth) acrylate;
Phosphorus-containing, boron-containing and / or silicon-containing (meth) acrylates such as 2- (dimethylphosphato) propyl (meth) acrylate, 2- (ethylphosphito) propyl (meth) acrylate, 2-dimethylphosphinomethyl (meta ) Acrylate, dimethylphosphonoethyl (meth) acrylate, diethyl-methacryloylphosphonate, dipropylmethacryloyl phosphate, 2- (dibutylphosphono) ethyl (meth) acrylate, 2,3-butylenemethacryloylethylborate, methyldiethoxymethacryloylethoxysilane Diethyl phosphatoethyl (meth) acrylate;
Sulfur-containing (meth) acrylates such as ethylsulfinylethyl (meth) acrylate, 4-thiocyanatobutyl (meth) acrylate, ethylsulfonylethyl (meth) acrylate, thiocyanatomethyl (meth) acrylate, methylsulfinylmethyl (meth) Acrylate, bis (methacryloyloxyethyl) sulfide;
Heterocyclic (meth) acrylates such as 2- (1-imidazolyl) ethyl (meth) acrylate, 2- (4-morpholinyl) ethyl (meth) acrylate and 1- (2-methacryloyloxyethyl) -2-pyrrolidone;
Vinyl halides such as vinyl chloride, vinyl fluoride, vinylidene chloride and vinylidene fluoride;
Vinyl esters such as vinyl acetate;
Vinyl monomers containing aromatic groups, such as styrene, substituted styrenes having alkyl substituents in the side chain, such as α-methyl styrene and α-ethyl styrene, substituted styrenes having alkyl substituents on the ring, such as vinyl toluene and p- Methylstyrene, halogenated styrene, such as monochlorostyrene, dichlorostyrene, tribromostyrene and tetrabromostyrene;
Heterocyclic vinyl compounds such as 2-vinylpyridine, 3-vinylpyridine, 2-methyl-5-vinylpyridine, 3-ethyl-4-vinylpyridine, 2,3-dimethyl-5-vinylpyridine, vinylpyrimidine, vinyl Piperidine, 9-vinylcarbazole, 3-vinylcarbazole, 4-vinylcarbazole, 1-vinylimidazole, 2-methyl-1-vinylimidazole, N-vinylpyrrolidone, 2-vinylpyrrolidone, N-vinylpyrrolidine, 3-vinylpyrrolidine , N-vinylcaprolactam, N-vinylbutyrolactam, vinyloxolane, vinylfuran, vinylthiophene, vinylthiolane, vinylthiazole and hydrogenated vinylthiazole, vinyloxazole and hydrogenated vinyloxazole;
Vinyl and isoprenyl ethers;
Maleic acid derivatives such as maleic anhydride, methylmaleic anhydride, maleimide, methylmaleimide;
Examples include fumaric acid and fumaric acid derivatives, such as mono- and diesters of fumaric acid.

  A monomer having a dispersed functional group can also be used as a comonomer. These monomers are well known in the art and usually contain heteroatoms such as oxygen and / or nitrogen. For example, the hydroxyalkyl (meth) acrylates, aminoalkyl (meth) acrylates and aminoalkyl (meth) acrylamides already described, ether alcohol (meth) acrylates, heterocyclic (meth) acrylates and heterocyclic vinyl compounds are dispersed comonomers. Is considered.

  Particularly suitable mixtures include methyl methacrylate, lauryl methacrylate and / or stearyl methacrylate.

  The components can be used individually or as a mixture.

The hydraulic fluid of the present invention preferably comprises a polyalkyl methacrylate polymer. These polymers that can be obtained by polymerizing compositions containing alkyl methacrylate monomers are well known in the art. Preferably, these polyalkylmethacrylate polymers comprise at least 40% by weight, in particular at least 50% by weight, more preferably at least 60% by weight and most preferably at least 80% by weight methacrylate repeat units. Preferably, these polyalkylmethacrylate polymers comprise C ₉ -C ₂₄ methacrylate repeating units and C ₁ -C ₈ methacrylate repeating units.

  The molecular weight of the alkyl ester-derived polymer is not critical. Usually, the polymer derived from an alkyl ester has a molecular weight in the range of 300 to 1,000,000 g / mol, preferably in the range of 10,000 to 200,000 g / mol, more preferably in the range of 25,000 to 100,000 g / mol, but is not limited thereto. These values are the weight average molecular weight of the polymer.

  While not intending to be limited thereby, the alkyl (meth) acrylate polymer has a polydispersity (mass average molecular weight of 1-15, preferably 1.1-10, particularly preferably 1.2-5. Obtained by the ratio Mw / Mn to the number average molecular weight). Polydispersity can be determined by gel permeation chromatography (GPC).

  The aforementioned monomer mixture can be polymerized by any known method. Traditional radical polymerization can be performed using conventional radical initiators. These initiators are well known in the art. Examples of these radical initiators are azo initiators such as 2,2′-azodiisobutyronitrile (AIBN), 2,2′-azobis (2-methylbutyronitrile) and 1,1 azo-biscyclohexanecarbox. Nitriles; peroxide compounds such as methyl ethyl ketone peroxide, acetylacetone peroxide, dilauryl peroxide, tert-butyl per-2-ethylhexanoate, ketone peroxide, methyl isobutyl ketone peroxide, cyclohexanone peroxide, dibenzoyl peroxide, tert-butyl perbenzoate, tert- Butylperoxyisopropyl carbonate, 2,5-bis (2-ethylhexanoyl-peroxy) -2,5-dimethylhexane, tert-butylperoxy-2-ethyl Ruhexanoate, tert-butylperoxy-3,5,5-trimethylhexanoate, dicumene peroxide, 1,1 bis (tertbutylperoxy) cyclohexane, 1,1 bis (tertbutylperoxy) 3,3,5-trimethylcyclohexane Cumene hydroperoxide and tert-butyl hydroperoxide.

  By using a chain transfer agent, a low molecular weight poly (meth) acrylate can be obtained. This technique is generally known and is practiced in the polymer industry and is described in Odian, Principles of Polymerization, 1991. Examples of chain transfer agents are sulfur-containing compounds such as thiols such as n-dodecanethiol and t-dodecanethiol, 2-mercaptoethanol, and mercaptocarboxylates such as methyl-3-mercaptopropionate. Suitable chain transfer agents contain up to 20, in particular up to 15, more preferably up to 12 carbon atoms. Furthermore, the chain transfer agent may contain at least 1, in particular at least 2 oxygen atoms.

  Furthermore, a low molecular weight poly (meth) acrylate can be obtained by using a transition metal complex such as a low spin cobalt complex. These techniques are well known and are described, for example, in USSR Patent 940,487-A and Heuts, et al, Macromolecules 1999, pp 2511-2519 and 3907-3912.

  In addition, novel polymerization techniques such as ATRP (Atom Transfer Radical Polymerization) and / or RAFT (Reversible Addition Fragmentation Chain Transfer) can be applied to obtain useful polymers derived from alkyl esters. These methods are well known. The ATRP reaction method is described in, for example, JS. Wang, et al. , J .; Am. Chem. Soc. , Vol. 117, pp. 5614-5615 (1995), and Matyjaszewski, Macromolecules, Vol. 28, pp. 7901-7910 (1995). Furthermore, the patent applications WO 96/30421, WO 97/47661, WO 97/18247, WO 98/40415 and WO 99/10387 disclose variants of the aforementioned ATRP, which is particularly referred to for the purpose of disclosure. The RAFT method is extensively presented in WO 98/01478, which is specifically referenced for purposes of disclosure.

  The polymerization can be carried out at normal pressure, reduced pressure or high pressure. The polymerization temperature is not critical. However, in general, the polymerization temperature is in the range of -20 to 200 ° C, preferably 0 to 130 ° C, particularly preferably 60 to 120 ° C, and is not intended to be limited thereto.

  The polymerization can be carried out with or without a solvent. The term solvent is understood broadly herein.

  According to a preferred embodiment, the polymer can be obtained by polymerization in API Group II or III mineral oil. These solvents have already been disclosed.

  Furthermore, polymers obtainable by polymerization in polyalphaolefins (PAO) are preferred. More preferably, the PAO has a number average molecular weight in the range of 200-10000, more preferably 500-5000. This solvent is disclosed above.

  The hydraulic fluid may comprise 0.5 to 50% by weight, in particular 1 to 30% by weight, preferably 3 to 20% by weight, of one or more polymers derived from alkyl esters, based on the total weight of the fluid. According to a preferred embodiment of the present invention, the hydraulic fluid comprises at least 5% by weight of one or more polymers derived from alkyl esters.

  According to a preferred aspect of the present invention, the fluid may comprise at least two polymers having different monomer compositions. Preferably at least one of the polymers is a polyolefin. Preferably, polyolefins are useful as viscosity index improvers.

  These polyolefins include in particular polyolefin copolymers (OCP) and hydrogenated styrene / diene copolymers (HSD). Polyolefin copolymers (OCP) used according to the invention are known per se. These are mainly polymers synthesized from ethylene, propylene, isoprene, butylene and / or further olefins having 5 to 20 carbon atoms. Systems grafted with small amounts of oxygen-containing monomers or nitrogen-containing monomers (e.g. 0.05-5% by weight maleic anhydride) can also be used. Copolymers containing a diene component are generally hydrogenated to reduce the oxidation sensitivity and crosslinking tendency of the viscosity index improver.

  The molecular weight Mw is generally 10,000 to 300,000, preferably 50,000 to 150,000. Such olefin copolymers are described, for example, in German published applications DE-A 16 44 941, DE-A 1769834, DE-A 1939037, DE-A 1963039 and DE-A 2059981.

  Ethylene / propylene copolymers are particularly useful and terpolymers with known ternary components such as ethylidene-norbornene (see Macromolecular Reviews, Vol. 10 (1975)) are also possible, but in the aging process their tendency to crosslink Must also be considered. Although the distribution can be substantially random, ordered polymers containing ethylene blocks can also be used advantageously. The monomer ethylene / propylene ratio varies within a range and can be set as an upper limit of about 75% for ethylene and about 80% for propylene. Polypropylene is not as suitable as an ethylene / propylene copolymer due to its reduced tendency to dissolve in oil. In addition to polymers incorporating predominantly atactic propylene, those incorporating more prominent isotactic or syndiotactic propylene can also be used.

  Such products are, for example, trade names: Dural® CO 034, Dural® CO 038, Dural® CO 043, Dural® CO 058, Buna® EPG 2050 or Buna. (Registered trademark) EPG 5050.

  Hydrogenated styrene / diene copolymers (HSD) are likewise known and these polymers are described, for example, in DE 2156122. These are generally hydrogenated isoprene / styrene or butadiene / styrene copolymers. The ratio of diene to styrene is preferably in the range of 2: 1 to 1: 2, particularly preferably about 55:45. The molecular weight Mw is generally 10,000 to 300,000, preferably 50,000 to 150,000. According to a particular embodiment of the invention, the proportion of double bonds after hydrogenation is 15% or less, particularly preferably 5% or less, relative to the number of double bonds before hydrogenation.

  Hydrogenated styrene / diene copolymers can be obtained commercially under the trade name SHELLVIS® 50, 150, 200, 250 or 260.

  Preferably, at least one of the polymers of the mixture comprises units derived from monomers selected from acrylate monomers, methacrylate monomers, fumarate monomers and / or maleate monomers. These polymers have already been described.

  The mass ratio of polyolefin to polymer comprises units derived from monomers selected from acrylate monomers, methacrylate monomers, fumarate monomers and / or maleate monomers, and is 1:10 to 10: 1, in particular 1: 5 to 5: 1. Range.

  The hydraulic fluid may contain conventional additives. These additives include, for example, antioxidants, antiwear agents, corrosion inhibitors and / or antifoaming agents, and are often purchased as commercial additive packages.

Preferably, hydraulic fluid, at 40 ° C. in accordance with ^{ASTM D 445, 10~150mm 2 / s} , even more preferably a viscosity in the range of 22~100mm ² / s.

Preferably, the hydraulic system includes the following components:
1. A unit that generates mechanical energy, such as a combustion engine or an electric motor.
2. A unit, such as a pump, that generates fluid flow or force and converts mechanical energy into fluid power.
3. A pipe that transmits fluid under pressure.
4). A unit that converts the fluid power of a fluid into mechanical work or motion, such as an actuator or fluid motor. There are two types of motors, cylindrical and rotary.
5). A control circuit having a valve that regulates flow, pressure, direction of motion, and applied force.
6). A fluid container that allows separation of water, foam, entrained air, or debris before returning clean fluid through the filter to the system.
7). A low compressibility liquid that can be operated without decomposition under applicable conditions (temperature, pressure, radiation).

  Most complex systems utilize a large number of pumps, rotary motors, and cylinders that are electrically controlled by valves and regulators.

  According to a preferred embodiment of the present invention, fluid power can be generated using a vane pump or a piston pump.

  The system can be operated at high pressure. The improvement of the invention can be achieved at pressures in the range of 50 to 700 bar, preferably 100 to 400 bar, more preferably 150 to 350 bar.

  A unit that generates mechanical energy, such as a motor, can be operated at a speed of 500 to 5000 rpm, preferably 1000 to 3000 rpm, more preferably 1400 to 2000 rpm.

  Hydraulic fluid can be used over a wide temperature range. Preferably the fluid can be used at a temperature in the range of -30 ° C to 200 ° C, more preferably 10 ° C to 150 ° C. Usually, the operating temperature depends on the base fluid used to produce the hydraulic fluid.

  Preferably, the fluid is used in military hydraulic systems, hydraulic launch assist systems (for hydraulic hybrid vehicle propulsion), industrial, marine, mining and / or mobile equipment hydraulic systems.

  Furthermore, the present invention includes a hydraulic fluid having a VI of at least 130, a unit for generating mechanical power, a unit for converting mechanical power into fluid power, and a unit for converting fluid power into mechanical work or motion. A hydraulic system is provided.

  Preferentially, engine speed can be maintained at a constant level to deliver more fluid power. Preferably, the mechanical output of the engine or electric motor can be operated at full output capacity to deliver more fluid power than hydraulic systems using standard HM grade fluids having a viscosity index of less than 120.

FIG. 1 shows a comparison of power at lower pressures (data from Table 6). FIG. 2 shows a comparison of power at lower pressures (data from Table 7).

  The invention is explained in more detail below by means of examples and comparative examples, but is not intended to limit the invention to these examples.

Examples 1 and 2 and Comparative Example 1
The Denison T6C mobile vane pump is operated under the following control conditions:
Speed = 1500 rpm, pressure = 200 bar, fluid temperature = 80 ° C.
One ISO VG46HM oil is used as a reference fluid to obtain a fluid power of 6.97 kW. For comparison, several ISO VG46HV oils were tested under the same conditions to obtain a 6-11% higher level hydraulic output as shown in Table 1.

Table 1-Denison T6C mobile vane pump output Comparative Example 1 Example 1

Operating conditions: 1500rpm, 200bar, 80 ° C
Examples 3 to 5 and Comparative Example 2
The Eaton-Vickers V20 vane pump is operated under the following controlled conditions: speed = 1200 rpm, pressure = 138 bar, fluid temperature = 80 ° C.
One ISO VG46HM oil is flowed as the reference fluid to obtain 8.69 kW of fluid power. For comparison, several ISO VG46HV oils were run under the same conditions to obtain 3-6% higher hydraulic output as shown in Table 2.

Table 2: Eaton-Vickers V20 vane pump output

Operating conditions: 1200rpm, 138bar, 80 ° C
Examples 6-8 and Comparative Example 3
The Eaton-Vickers V104C vane pump is operated under the following control conditions:
Speed = 1200 rpm, pressure = 138 bar, fluid temperature = 80 ° C.
One ISO VG46HM oil is used as a reference fluid to obtain 8.35 kW of fluid power. For comparison, several ISO VG46HV oils were tested under the same conditions to obtain a hydraulic output level 5-7% higher as shown in Table 3.

Table 3: Eaton-Vickers V104C vane pump output

Operating conditions: 1200rpm, 138bar, 80 ° C
Examples 9 to 11 and Comparative Example 4
The Komatsu 35 + 35 dual piston pump is operated under the following control conditions:
Speed = 2100 rpm, pressure = 350 bar, fluid temperature = 100 ° C.
One ISO VG46HM oil was used as a reference fluid and a fluid power of 5.83 kW was obtained. For comparison, several ISO VG46HV oils were tested under the same conditions to obtain 4-6% higher levels of hydraulic output, as shown in Table 4.

Table 4: Komatsu 35 + 35 double piston pump output

Operating conditions: 2100 rpm, 350 bar, 100 ° C.
Examples 12-14 and Comparative Example 5
Operate the Eaton L2 gear pump under the following control conditions:
Speed = 2750 rpm, pressure = 207 bar, fluid temperature = 80 ° C.
One ISO VG46HM oil is used as a reference fluid and a fluid power of 21.5 kW is obtained. For comparison, several ISO VG46HV oils were run under the same conditions to obtain a 6-8.8% higher level hydraulic output, as shown in Table 5.

Table 5 Eaton L2 gear pump output

Operating conditions: 2750 rpm, 207 bar, 80 ° C.
The data collected in the examples show that “HV” multi-grate oil formulated with Group II PAMA increased the hydraulic output obtained from the hydraulic pump. The increased work output allows the excavator to complete the work cycle in a shorter time, thus completing a higher level of work output in the same time.

Examples 15 to 18 and Comparative Example 6
A further advantage of the present invention is the ability to design hydraulic systems that operate at lower pressures and deliver equal amounts of hydraulic output. Table 6 contains data comparing the relative input and hydraulic output on the Denison P09 piston pump at about 5000 psi (345 bar).

Table 6: Comparison of piston pump output at low pressure

  The data is further represented graphically in FIG. 1 and shows that a system delivering an equal level of hydraulic output can be designed to operate at 5% lower pressure.

Examples 19 to 22 and Comparative Example 7
Further experiments show that the relative input and hydraulic output in the Denison T6C vane pump at about 3000 psi (207 bar) is improved by the present invention. The results obtained are shown in Table 7. In addition, the data is graphically represented in FIG. 2 and shows that a system that delivers equal levels of hydraulic power can be designed to operate at 6% lower pressure.

Table 7: Comparison of vane pump output at low pressure

Claims (53)

  Use of a fluid having a VI of at least 130 to improve the output of the hydraulic system.   Use according to claim 1, wherein the output is increased by at least 3%.   Use according to claim 2, wherein the output is increased by at least 5%.   4. Use according to any one of claims 1 to 3, wherein the volume output is increased.   Use according to claim 4, wherein the volumetric output is increased by at least 3%.   6. Use according to claim 5, wherein the volume output is increased by at least 5%.   7. Use according to any one of claims 1 to 6, wherein the invariance of the output is increased.   Use according to claim 7, wherein the invariance of the output increases at maximum load.   Use according to claim 7 or 8, wherein the decrease in power after an operating time of at least 10 minutes is a maximum of 3%, measured at a load of 90% or more of the maximum load of the unit providing mechanical energy.   Use according to any one of claims 1 to 9, wherein the engine speed of the unit providing mechanical energy is maintained at a constant speed and the system delivers an increased level of fluid power.   Use according to any one of claims 1 to 10, wherein the engine speed of the unit providing mechanical energy is in the range of 1000 to 3000 rpm.   Use according to claim 11, wherein the engine speed of the unit providing mechanical energy is in the range of 1400-2000rpm.   13. Use according to any one of claims 1 to 12, wherein the pressure provided by the unit providing the fluid power is in the range of 50-700 bar.   14. Use according to claim 13, wherein the pressure provided by the unit providing fluid power is in the range of 150-350 bar.   15. A hydraulic system is designed to operate at a lower pressure and the output is equal to that delivered by a reference system using a hydraulic fluid having a VI of 100. Use of any one of Claims.   An improvement in the ratio of hydraulic output to input such that the output / input ratio is improved by at least 3% compared to that delivered by a reference system using a hydraulic fluid having a VI of 100. Use according to any one of claims 1 to 15, which is indicated.   17. Use according to any one of claims 1 to 16, wherein the fluid has a VI of at least 150.   18. Use according to claim 17, wherein the fluid has a VI of at least 180.   19. Use according to any one of claims 1 to 18, wherein the fluid is an NFPA double viscosity grade, triple viscosity grade, quadra viscosity grade, or pentavisibility grade hydraulic fluid.   20. Use according to any one of claims 1 to 19, wherein the fluid can be obtained by mixing a base fluid and a polymer viscosity index improver.   21. Use according to claim 20, wherein the fluid comprises at least 60% by weight of at least one base fluid.   The use according to claim 21, wherein the fluid comprises at least 60% by weight of at least one base fluid having a viscosity index of 120 or less.   23. Use according to any one of claims 1 to 22, wherein the fluid comprises mineral oil and / or synthetic oil.   24. The use of claim 23, wherein the fluid comprises API Group I, API Group II, API Group III oil, API Group IV or API Group V oil, or Fischer-Tropsch (GTL) based oil.   25. Use according to any one of claims 1 to 24, wherein the fluid comprises polyalphaolefin (PAO), carboxylic acid ester, vegetable ester, phosphate ester and / or polyalkylene glycol (PAG).   26. Use according to any one of claims 1 to 25, wherein the fluid comprises at least one polymer.   27. Use according to claim 26, wherein the polymer comprises units derived from monomers selected from acrylate monomers, methacrylate monomers, fumarate monomers and / or maleate monomers.   28. Use according to claim 27, wherein the fluid comprises a polyalkylmethacrylate polymer. Fluid
a) 0 to 100% by weight of one or more formulas (I) with respect to the total weight of the ethylenically unsaturated monomers

Wherein R is hydrogen or methyl, R ¹ means a straight or branched alkyl residue having 1 to 6 carbon atoms, R ² and R ³ are independently hydrogen or formula An ethylenically unsaturated ester compound of -COOR ', wherein R' represents hydrogen or an alkyl group having 1 to 6 carbon atoms],
b) 0 to 100% by weight of one or more formulas (II) relative to the total weight of the ethylenically unsaturated monomers

Wherein R is hydrogen or methyl, R ⁴ represents a straight or branched alkyl residue having 7 to 40 carbon atoms, R ⁵ and R ⁶ are independently hydrogen or formula An ethylenically unsaturated ester compound of -COOR ", wherein R" means hydrogen or an alkyl group having 7 to 40 carbon atoms],
29. Any of claims 26 to 28, comprising c) a polymer obtainable by polymerizing a mixture of olefinically unsaturated monomers consisting of 0-50% by weight of comonomer with respect to the total weight of ethylenically unsaturated monomers. Or use according to item 1.   30. Use according to any one of claims 26 to 29, wherein the polymer can be obtained by polymerization in API Group II or Group III mineral oil.   30. Use according to any one of claims 26 to 29, wherein the polymer can be obtained by polymerization in polyalphaolefins (PAO).   32. Use according to any one of claims 26 to 31, wherein the polymer can be obtained by polymerizing a mixture comprising dispersed monomers.   Use according to any one of claims 26 to 32, wherein the polymer can be obtained by polymerizing a mixture comprising vinyl monomers containing aromatic groups.   34. Use according to any one of claims 26 to 33, wherein the polymer has a molecular weight in the range from 10,000 to 200,000 g / mol, in particular from 25000 g / mol to 100,000 g / mol.   35. Use according to any one of claims 26 to 34, wherein the fluid comprises 0.5 to 40% by weight of polymer.   36. Use according to claim 35, wherein the fluid comprises from 3 to 20% by weight of polymer.   37. Use according to any one of claims 26 to 36, wherein the fluid comprises at least two polymers having different monomer compositions.   38. Use according to claim 37, wherein at least one of the polymers is a polyolefin.   40. Use according to claim 38, wherein at least one of the polymers comprises units derived from alkyl ester monomers.   40. Use according to claim 39, wherein the mass ratio of polyolefin to polymer comprising monomer units derived from alkyl esters is in the range of 1:10 to 10: 1.   41. Use according to any one of claims 1 to 40, wherein the fluid comprises an oxygen-containing compound selected from the group of carboxylic acid esters, polyether polyols and / or organophosphorus compounds.   42. Use according to claim 41, wherein the oxygen-containing compound is a carboxylic acid ester comprising at least two ester groups.   43. Use according to claim 41 or 42, wherein the oxygen-containing compound is a diester of a carboxylic acid containing 4 to 12 carbon atoms.   42. Use according to claim 41, wherein the oxygen-containing compound is an ester of a polyol.   45. Use according to any one of claims 1 to 44, wherein the fluid has an ISO viscosity grade in the range of 15 to 150.   The use according to any one of claims 1 to 45, wherein the fluid is used at a temperature in the range of -40C to 120C.   47. Use according to any one of claims 1 to 46, wherein the fluid comprises an antioxidant, an antiwear agent, a corrosion inhibitor and / or an antifoam agent.   48. The fluid is used in a military hydraulic system, a hydraulic launch assist system (for hydraulic hybrid vehicle propulsion), industrial, marine, mining and / or mobile equipment hydraulic systems. The use according to any one of the above.   At least one unit for providing fluid with mechanical energy, at least one unit for converting mechanical energy into fluid power, at least one pipe for transmitting fluid under pressure, and mechanical fluid power of fluid 49. Use according to any one of claims 1 to 48, for use in a hydraulic system comprising at least one unit for converting to work.   49. Use according to claim 48, wherein the unit providing mechanical energy comprises a combustion engine.   51. Use according to claim 49 or 50, wherein the unit for converting mechanical energy into fluid power is a vane pump.   51. Use according to claim 49 or 50, wherein the unit for converting mechanical energy into fluid power is a piston pump.   51. Use according to claim 49 or 50, wherein the unit for converting mechanical energy into fluid power is a gear pump.

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