WATER-BASED LUBRICANT FOR METALWORKING

Abstract

The invention relates to a lubricating composition comprising water and: - from 0.05 to 40% by weight of at least two polyalkylene glycols, PAG1 and PAG2, the ratio between the molar mass of PAG1 and the molar mass of PAG2 being strictly less than 1; - from 0.001 to 30% by weight of at least one cellulosic compound, relative to the total weight of the lubricating composition. The present invention also relates to the use of the lubricating composition according to the invention for metalworking.

Description

Title of the invention: AQUEOUS LUBRICANT FOR METALWORKING TECHNICAL FIELD OF THE INVENTION

[0001] The present invention relates to the field of lubricating compositions, and more particularly to lubricating compositions used in metalworking processes, in particular for machining (turning, milling, drilling, sawing, threading among others), forming, cutting, stamping or even rolling of metal parts. In particular, the present invention relates to aqueous-based lubricating compositions. STATE OF THE ART

[0002] Lubricating compositions, also called "lubricants", are commonly used in mechanical systems to reduce friction between parts and thus protect them against wear. In addition to wear phenomena, friction can oppose the relative movement of the parts in contact and induce energy losses that are detrimental to optimal operation of the mechanical system.

[0003] Lubricants are used for multiple applications, from the lubrication of combustion vehicle engines to the lubrication of equipment used for machining operations, commonly known as metalworking, in particular for metal deformation operations.

[0004] Metalworking more generally corresponds to the implementation of mechanical or metallurgical processes, both diversified and more specialized, which can be defined as shaping, cutting or joining processes. This can also concern any mechanical transformation of metal, such as machining (turning, milling, drilling, sawing, threading among others), forming, cutting, stamping or even rolling.

[0005] Operations relating to metalworking particularly require the use of lubricating compositions, with the aim of reducing the friction forces between the metal parts in contact and preventing their premature wear, while advantageously guaranteeing cooling of the latter.

[0006] These lubricating compositions, dedicated to lubrication in metal machining processes, are also commonly referred to as “metalworking compositions or fluids”, “machining lubricants or fluids” or “cutting lubricants or fluids”.

[0007] Conventionally, the lubricating formulations used for such machining operations are lubricants composed mainly of one or more oils of base, which are generally associated with additives dedicated to boosting the lubricating performance of base oils, such as friction modifier additives.

[0008] Generally speaking, these lubricating formulations are classified according to the type of oil they incorporate. Thus:

[0009] - Mineral fluids, non-renewable, are those comprising oils mineral oils, such as paraffinic, aromatic or naphthenic oils, in their basic formulation;

[0010] - Renewable fluids, of plant or animal origin, are those comprising vegetable, animal oils or fats in their basic formulation;

[0011] - Mineral fluids of synthetic origin are those comprising oils mineral or chemically modified petrochemical derivatives, in their basic formulation such as, for example, polyalphaolefins, polyalkylene glycols and hydrogenated mineral oils;

[0012] - Renewable fluids of synthetic origin are those comprising oils chemically modified vegetable or animal oils, in their basic formulation such as, for example, vegetable oil esters, sulphated, oxidised, esterified vegetable oils or even sulphated animal oils.

[0013] Some formulations, called mixed, include a mixture of the oils listed above in their basic formulation. The best known are called semi-synthetic oils and correspond to a mixture of synthetic and mineral oils.

[0014] However, the use of oils or greases in lubricating compositions for metalworking has several disadvantages. In particular, oil-based lubricants generally have low resistance to microbial attack, poor cooling properties or a negative impact on the working environment, health or safety.

[0015] Lubricants in emulsion form, comprising an aqueous phase added to an oily phase, have thus been developed. However, these lubricants have low stability partly due to water hardness and / or salinity.

[0016] In order to solve the problems associated with the implementation of oil-based lubricating formulations in metalworking applications, water-based compositions have shown some interest. These formulations generally comprise water, supplemented with various water-soluble additives in order to ensure the tribological properties required for lubricants, in particular in terms of friction reduction and protection of parts against wear.

[0017] Unfortunately, the use of aqueous lubricants for application in metalworking has a major disadvantage related to the formation of what are called "gummy residues".

[0018] These gummy residues appear after the machining operations. Once the machining equipment is stopped, the lubricant, subjected to ambient dehydration, is likely to lead to the formation of salts which, combined with the polymers present in the lubricant, can form relatively viscous and insoluble residues in the aqueous phase, referred to as "gummy residues".

[0019] Gummy residues adhere to the walls of the tooling and are likely to cause the machining tool to jam, generally requiring undesirable maintenance operations on the machine.

[0020] Thus, there remains a need to have an aqueous lubricating composition, for metalworking, generating little or no gummy residue, while maintaining, or even improving, the tribological properties of the lubricant, particularly in terms of anti-wear and extreme pressure properties.

[0021] In metalworking, the lubricating composition used for metalworking is likely to come into contact with oils or greases. It is desirable to have a lubricating composition for metalworking which has the ability to separate from these oils or greases in order to avoid losses in product performance due to pollution by foreign oils.

[0022] An objective of the present invention is to provide a lubricating composition, in particular a lubricating composition for metalworking, limiting residue formation and wear and having good oil separation capacity. Summary of the invention

[0023] The invention relates to a lubricating composition comprising water and:

[0024] - from 0.05 to 40% by weight of at least two polyalkylene glycols PAG1 and PAG2, the ratio between the molar mass of PAG1 and the molar mass of PAG2 being strictly less than 1.

[0025] - from 0.001 to 30% by weight of at least one cellulose compound,

[0026] relative to the total weight of the lubricating composition.

[0027] Preferably, the ratio between the molar mass of PAG1 and the molar mass of PAG2 is less than or equal to 0.8, preferably less than or equal to 0.7, more preferably less than or equal to 0.5.

[0028] Preferably, the molar mass of PAG1 ranges from 500 to 2000 g / mol, preferably from 700 to 1800 g / mol, and / or the molar mass of PAG2 ranges from 1500 to 5000 g / mol, preferably from 2000 to 4000 g / mol, it being understood that the ratio between the molar mass of PAG1 and the molar mass of PAG2 is strictly less than 1.

[0029] According to one embodiment, the composition further comprises a third polyalkylene glycol PAG3, said PAG3 preferably having a molar mass ranging from 500 to 2000 g / mol, preferably 700 to 1800 g / mol, PAG3 having a molar mass different from PAG1 and different from PAG2, PAG3 preferably having at least one methyl end, advantageously one methyl end and one butyl end.

[0030] According to one embodiment, the composition comprises:

[0031] - from 0.05 to 30% by weight, preferably from 0.1 to 15% by weight, more preferably from 0.15 to 10% by weight of PAG1,

[0032] - from 0.01 to 30%, preferably from 0.05 to 15% by weight, more preferably from 0.1 to 10% by weight of PAG2,

[0033] - optionally from 0.01 to 10% by weight, preferably from 0.02 to 7% by weight, of preferably still from 0.05 to 5% by weight of PAG3,

[0034] relative to the total weight of the lubricating composition.

[0035] Preferably, the composition further comprises at least one anti-corrosion system comprising at least one acid and at least one base, at least one base preferably being chosen from amines, advantageously from alkanolamines.

[0036] Preferably, said at least one cellulose compound is chosen from alkylcelluloses, dialkylcelluloses, hydroxyalkylcelluloses, carboxyalkylcelluloses, and mixtures thereof, preferably from hydroxyalkylcelluloses, advantageously said at least one cellulose compound is a hydroxyethylcellulose.

[0037] Preferably, the polyalkylene glycol(s) are chosen from poly(ethylene glycol), poly(propylene glycol), copolymers comprising ethylene oxide units and propylene oxide units, and mixtures thereof, preferably from block copolymers comprising ethylene oxide units and propylene oxide units and mixtures thereof, more preferably from ethylene oxide-propylene oxide diblock copolymers and propylene oxide-ethylene oxide-propylene oxide triblock copolymers and mixtures thereof.

[0038] According to one embodiment, the composition is a ready-to-use composition comprising water and:

[0039] - from 0.05 to 15% by weight, preferably from 0.05 to 10% by weight, preferably from 0.1 5% by weight of polyalkylene glycol,

[0040] - from 0.005 to 5% by weight, preferably from 0.005 to 1% by weight, preferably from 0.005 to 0.5% by weight of at least one cellulose compound,

[0041] relative to the total weight of the lubricating composition.

[0042] According to one embodiment, the composition is a concentrated composition comprising water and:

[0043] - from 0.5 to 30% by weight, preferably from 1 to 20% by weight, preferably from 2 to 15% by weight, polyalkylene glycol,

[0044] - from 0.05 to 10% by weight, preferably from 0.05 to 5% by weight, preferably from 0.1 to 1% by weight of at least one cellulose compound,

[0045] relative to the total weight of the lubricating composition.

[0046] According to one embodiment, the composition is a ready-to-use composition comprising:

[0047] - from 0.05 to 15% by weight, preferably from 0.05 to 10% by weight, more preferably from 0.1 to 5% by weight of a first polyalkylene glycol PAG1,

[0048] - from 0.05 to 15% by weight, preferably from 0.05 to 10% by weight, preferably from 0.1 at 5% by weight of a second polyalkylene glycol PAG2, it being understood that the ratio between the molar mass of PAG1 and the molar mass of PAG2 is strictly less than 1,

[0049] - optionally from 0.01 to 5% by weight, preferably from 0.02 to 2% by weight, of preferably still from 0.05 to 1% by weight, of a third polyalkylene glycol PAG3,

[0050] - from 0.005 to 5% by weight, preferably from 0.005 to 1% by weight, preferably from 0.005 to 0.5% by weight of cellulose compound(s),

[0051] - at least 60% by weight of water, preferably at least 70% by weight of water, preferably at least 80% by weight of water,

[0052] - possibly:

[0053] o from 0.01 to 10% by weight, preferably from 0.01 to 5% by weight, preferably from 0.05 to 5% by weight, of acid(s), at least one acid being an aliphatic acid, and

[0054] o from 0.01 to 10% by weight, preferably from 0.01 to 5% by weight, preferably from 0.05 to 5% by weight, of base(s),

[0055] relative to the total weight of the lubricating composition.

[0056] According to one embodiment, the composition is a concentrated composition comprising:

[0057] - from 0.5 to 30% by weight, preferably from 1 to 20% by weight, preferably from 2 to 15% by weight of a first polyalkylene glycol PAG1,

[0058] - from 0.5 to 30% by weight, preferably from 1 to 20% by weight, preferably from 2 to 15% by weight of a second polyalkylene glycol PAG2, it being understood that the ratio between the molar mass of PAG1 and the molar mass of PAG2 is strictly less than 1,

[0059] - optionally from 0.1 to 15% by weight, preferably from 0.1 to 10% by weight, of preferably still from 0.5 to 5% by weight of a third polyalkylene glycol PAG3,

[0060] - from 0.05 to 10% by weight, preferably from 0.05 to 5% by weight, preferably from 0.1 to 1% by weight of cellulose compound(s),

[0061] - at least 30% by weight of water, preferably at least 40% by weight of water, of preferably at least 45% by weight of water,

[0062] - possibly:

[0063] o from 0.5 to 20% by weight, preferably from 0.5 to 15% by weight, preferably from 1 to 15% by weight of acid(s), at least one acid being an aliphatic acid, and

[0064] o from 0.5 to 25% by weight, preferably from 0.5 to 20% by weight, preferably from 1 to 20% by weight, of base(s),

[0065] relative to the total weight of the lubricating composition.

[0066] According to a particular embodiment of the composition according to the invention:

[0067] - the first polyalkylene glycol PAG1 is a copolymer comprising units ethylene oxide and propylene oxide units and having a molar mass ranging from 500 to 2000 g / mol, PAG1 having at least one alkyl terminal group having from 1 to 5 carbon atoms, and

[0068] - the second polyalkylene glycol PAG2 is a copolymer comprising units ethylene oxide and propylene oxide units and having a molar mass ranging from 1500 to 5000 g / mol, PAG2 having two hydroxyl terminal groups, it being understood that the ratio between the molar mass of PAG1 and the molar mass of PAG2 is strictly less than 1, and

[0069] - where appropriate, the third polyalkylene glycol PAG3 is a copolymer comprising ethylene oxide units and propylene oxide units and having a molar mass ranging from 500 to 2000 g / mol, PAG3 having a molar mass different from PAG1, PAG3 having at least one alkyl terminal group having from 1 to 5 carbon atoms, and

[0070] - the cellulose compound is a hydroxyethylcellulose.

[0071] The invention also relates to the use of the lubricating composition according to the invention, as a fluid for working metals, in particular for machining (turning, milling, drilling, sawing, threading among others), forming, cutting, stamping or even rolling of metal parts, the metal preferably being steel.

[0072] The invention also relates to the use of the lubricating composition according to the invention for improving the eco-performance of a process comprising at least one metalworking step, in which the eco-performance is chosen from:

[0073] - the reduction of the energy consumed for the implementation of the process,

[0074] - increasing the productivity of the process,

[0075] - improving the safety of process operators,

[0076] eco-performance being chosen in particular from the improvement of the safety of the process operators.

[0077] The invention makes it possible to provide a multi-service lubricating composition since it can be implemented on different types of metal surfaces, in particular aluminum surfaces and steel surfaces.

[0078] The lubricating composition according to the invention makes it possible to limit the formation of viscous residues. However, these viscous or gummy residues can accumulate on the tools machining and can form a polymeric film that is difficult to remove. The lubricating composition according to the invention makes it possible to limit the formation of these deposits but also makes it possible to facilitate the redissolution of these gummy residues.

[0079] Furthermore, the lubricating composition according to the invention has excellent anti-wear properties.

[0080] Finally, the lubricating composition according to the invention has a very good capacity to separate from an oil or a grease, so that it is stable over time since it retains performance for longer without being polluted by these foreign oils or greases.

[0081] The invention also makes it possible to provide a lubricating composition having a good toxicological profile and a low impact on the environment.

[0082] The invention makes it possible to provide a lubricating composition which does not generate oil deposits on the ground, which increases operator safety and thus improves the eco-design profile of the composition. DETAILED DESCRIPTION OF THE INVENTION

[0083] The invention relates to a lubricating composition comprising water and: - from 0.05 to 40% by weight, preferably from 0.1 to 30% by weight, preferably from 0.1 to 20% by weight, of at least two polyalkylene glycols PAG1 and PAG2, the ratio between the molar mass of PAG1 and the molar mass of PAG2 being strictly less than 1. - from 0.001 to 30% by weight, preferably from 0.005 to 10% by weight, preferably from 0.005 to 2% by weight, of at least one cellulose compound,

[0084] relative to the total weight of the lubricating composition.

[0085] The lubricating composition according to the invention may be a ready-to-use composition or a concentrated composition, also called a composition to be diluted.

[0086] Indeed, the lubricating composition according to the invention can be diluted with the addition of water before being used as a fluid for metalworking. For example, the concentrated composition can be diluted with a dilution rate ranging from 3 to 30%, or even from 5 to 20%. This is therefore a dilution rate expressed by volume.

[0087] When the composition is ready for use, it can be used directly as a metalworking fluid, without the need to dilute it.

[0088] When the composition is a ready-to-use composition, it preferably comprises water and: - from 0.05 to 15% by weight, preferably from 0.05 to 10% by weight, preferably from 0.1 to 5% by weight, of polyalkylene glycol, - from 0.005 to 5% by weight, preferably from 0.005 to 1% by weight, preferably from 0.005 to 0.5% by weight, of at least one cellulose compound,

[0089] relative to the total weight of the lubricating composition.

[0090] According to one embodiment, when the composition is a ready-to-use composition, it comprises: - from 0.05 to 15% by weight, preferably from 0.05 to 10% by weight, preferably from 0.1 to 5% by weight, of polyalkylene glycol, - from 0.005 to 5% by weight, preferably from 0.005 to 1% by weight, preferably from 0.005 to 0.5% by weight, of at least one cellulose compound, - at least 60% by weight of water, preferably at least 70% by weight of water, preferably at least 80% by weight of water - possibly : • from 0.01 to 10% by weight, preferably from 0.01 to 5% by weight, preferably from 0.05 to 5% by weight, of aliphatic acid(s), and • from 0.01 to 10% by weight, preferably from 0.01 to 5% by weight, preferably from 0.05 to 5% by weight, of base(s),

[0091] relative to the total weight of the lubricating composition.

[0092] When the composition is a composition to be diluted (concentrated), it preferably comprises water and: - from 0.5 to 30% by weight, preferably from 1 to 20% by weight, preferably from 2 to 15% by weight, of polyalkylene glycol, - from 0.05 to 10% by weight, preferably from 0.05 to 5% by weight, preferably from 0.1 to 1% by weight, of at least one cellulose compound,

[0093] relative to the total weight of the lubricating composition.

[0094] According to one embodiment, when the composition is a composition to be diluted (concentrated), it comprises: - from 0.5 to 30% by weight, preferably from 1 to 20% by weight, preferably from 2 to 15% by weight, of polyalkylene glycol, - from 0.05 to 10% by weight, preferably from 0.05 to 5% by weight, preferably from 0.1 to 1% by weight, of at least one cellulose compound, - at least 30% by weight of water, preferably at least 40% by weight of water, preferably at least 45% by weight of water, - possibly : • from 0.5 to 20% by weight, preferably from 0.5 to 15% by weight, preferably from 1 to 15% by weight, of aliphatic acid(s), and • from 0.5 to 25% by weight, preferably from 0.5 to 20% by weight, preferably from 1 to 20% by weight, of base(s),

[0095] relative to the total weight of the lubricating composition. Polyalkylene glycol (PAG)

[0096] The lubricating composition according to the invention comprises at least two PAGs, called PAG1 and PAG2. PAG can be a polymer or a copolymer. When it is a copolymer, it can be a random copolymer or a block copolymer.

[0097] According to one embodiment, the PAG(s) of the lubricating composition according to the invention are chosen from PAGs comprising alkylene oxide units comprising from 2 to 12 carbon atoms, preferably from 2 to 8 carbon atoms, more preferably from 2 to 4 carbon atoms.

[0098] Typically, in the context of the present invention, if the PAG comprises a terminal group of hydroxyl type (-OH) and a terminal group of alkyl type, then said terminal group of alkyl type comprises from 1 to 5 carbon atoms.

[0099] According to one embodiment, the PAG(s) used in the lubricating composition according to the invention corresponds to formula (I):

[0100] R-(OA)ZOR' (I)

[0101] in which:

[0102] R and R' represent, independently of one another, a hydrogen atom or alkyl group, linear or branched, comprising from 1 to 5 carbon atoms;

[0103] A, all identical or different, represents an alkyl group, linear or branched, comprising from 2 to 8 carbon atoms;

[0104] z represents an integer greater than or equal to 2, preferably an integer greater than or equal to 4.

[0105] According to one embodiment, the PAG(s) of the lubricating composition according to the invention are chosen from poly(ethylene glycol) (PEG), poly(propylene glycol) (PPG), copolymers comprising ethylene oxide units and propylene oxide units, and mixtures thereof, preferably from block copolymers comprising ethylene oxide units and propylene oxide units and mixtures thereof, more preferably from ethylene oxide-propylene oxide diblock copolymers, propylene oxide-ethylene oxide-propylene oxide triblock copolymers, ethylene oxide-propylene oxide-ethylene oxide triblock copolymers, and mixtures thereof.

[0106] For the purposes of the present invention, the term "copolymers comprising ethylene oxide units and propylene oxide units" means copolymers comprising at least units resulting from the polymerization of ethylene glycol and at least units resulting from the polymerization of propylene glycol. These polymers may be, for example, block copolymers or random copolymers.

[0107] By "block copolymers comprising ethylene oxide units and propylene oxide units" within the meaning of the present invention, we mean copolymers comprising at least one block resulting from the polymerization of ethylene glycol and at least one block resulting from the polymerization of propylene glycol. They can then be called PEG / PPG.

[0108] For the purposes of the present invention, the term "ethylene oxide-propylene oxide diblock copolymers" means copolymers consisting of two blocks, one block resulting from the polymerization of ethylene glycol and one block resulting from the polymerization of propylene glycol. They can then be called PEG-PPG.

[0109] For the purposes of the present invention, the term "propylene oxide-ethylene oxide-propylene oxide triblock copolymers" means copolymers consisting of three blocks, sequenced, one block resulting from the polymerization of propylene glycol, one block resulting from the polymerization of ethylene glycol and one block resulting from the polymerization of propylene glycol (in this order). They can then be called PPG-PEG-PPG.

[0110] For the purposes of the present invention, the term "ethylene oxide-propylene oxide-ethylene oxide triblock copolymers" means copolymers consisting of three blocks, sequenced, one block resulting from the polymerization of ethylene glycol, one block resulting from the polymerization of propylene glycol and one block resulting from the polymerization of ethylene glycol (in this order). They can then be called PEG-PPG-PEG.

[0111] One or more of the PAGs used in the invention may optionally comprise alkyl end groups, for example chosen from linear or branched alkyl groups comprising from 1 to 8 carbon atoms, preferably from 1 to 5 carbon atoms. The inventors have in fact observed that the presence of at least one alkyl type end group, in particular a methyl type end group, allows the lubricating composition of the invention to have better cleaning properties.

[0112] According to one embodiment, the PAGs used in the lubricating composition according to the invention correspond to one of the formulas (II) to (V):

[0113] R-(OCH2CH2)x(OCH2CH(CH3))yOR' (II);

[0114] R-(OCH2CH(CH3))y(OCH2CH2)xOR' (III);

[0115] R-(OCH2CH(CH3))y(OCH2CH2)x(OCH2CH(CH3))y OR' (IV);

[0116] R-(OCH2CH2)x(OCH2CH(CH3))y(OCH2CH2)x OR' (V);

[0117] in which:

[0118] R and R' represent, independently of one another, a hydrogen atom or a saturated, linear or branched alkyl group comprising from 1 to 5 carbon atoms;

[0119] x and x', identical or different, represent an integer greater than or equal to 2, preferably greater than or equal to 4,

[0120] y and y', identical or different, represent an integer greater than or equal to 2.

[0121] Preferably, in the compounds of formula (II), (III), (IV) or (V) according to the invention, x, x', y and y' are, independently of each other, an integer ranging from 2 to 30, preferably from 4 to 25, advantageously from 6 to 20.

[0122] Preferably, in formula (IV), x is an integer ranging from 2 to 30, preferably from 4 to 25, advantageously from 6 to 20, and the sum y+y' ranges from 8 to 45, preferably from 12 to 40, preferably still from 20 to 35.

[0123] Preferably, in formula (V), y is an integer ranging from 2 to 30, preferably from 4 to 25, advantageously from 6 to 20, and the sum x+x' ranges from 8 to 45, preferably from 12 to 40, more preferably from 20 to 35.

[0124] According to one embodiment, PAG1 has at least one terminal group of alkyl type, in particular alkyl comprising from 1 to 5 carbon atoms, and / or PAG2 has at least one terminal hydroxyl group, advantageously two terminal hydroxyl groups.

[0125] When the composition comprises three PAGs, advantageously, PAG1 will have a hydroxyl terminal group and an alkyl terminal group, PAG2 will have two hydroxyl terminal groups, and PAG3 will have two alkyl terminal groups.

[0126] According to one embodiment, the ratio between the molar mass of PAG1 and the molar mass of PAG2 is less than or equal to 0.8, preferably less than or equal to 0.7, more preferably less than or equal to 0.5.

[0127] According to one embodiment, PAG1 has a molar mass ranging from 500 to 2000 g / mol, preferably from 700 to 1800 g / mol.

[0128] According to one embodiment, PAG2 has a molar mass ranging from 1500 to 5000 g / mol, preferably from 2000 to 4000 g / mol, it being understood that the ratio between the molar mass of PAG1 and the molar mass of PAG2 is strictly less than 1, preferably less than or equal to 0.8, preferably less than or equal to 0.7, more preferably less than or equal to 0.5.

[0129] The molar mass of the PAGs can be determined according to any method well known to those skilled in the art, for example by size exclusion chromatography.

[0130] The lubricating composition may optionally comprise a third polyalkylene glycol, called PAG3. In the context of the invention, PAG3 will be different from PAG1 and different from PAG2, the difference being able to be for example the molar mass and / or the terminal groups.

[0131] According to one embodiment, PAG3 has a molar mass ranging from 500 to 2000 g / mol, preferably from 700 to 1800 g / mol.

[0132] According to one embodiment, PAG3 has a methyl end, advantageously a methyl end and a butyl end.

[0133] According to a particular embodiment, the lubricating composition comprises: - from 0.05 to 30% by weight, preferably from 0.1 to 15% by weight, more preferably from 0.15 to 10% by weight, of PAG1, said PAG1 preferably having a molar mass ranging from 500 to 2000 g / mol, preferably from 700 to 1800 g / mol, - from 0.01 to 30%, preferably from 0.05 to 15% by weight, more preferably from 0.1 to 10% by weight of PAG2, said PAG2 preferably having a molar mass ranging from 1500 to 5000 g / mol, preferably from 2000 to 4000 g / mol, it being understood that the ratio between the molar mass of PAG1 and the molar mass of PAG2 is strictly less than 1, preferably less than or equal to 0.8, preferably less than or equal to 0.7, more preferably less than or equal to 0.5, - optionally from 0.01 to 10% by weight, preferably from 0.02 to 7% by weight, more preferably from 0.05 to 5% by weight of PAG3, said PAG3 preferably having a molar mass ranging from 500 to 2000 g / mol, preferably from 700 to 1800 g / mol,

[0134] relative to the total weight of the lubricating composition.

[0135] According to one embodiment, PAG1 has a pour point below 0°C, preferably below -15°C, more preferably below -20°C.

[0136] According to one embodiment, PAG2 has a pour point below +10°C, preferably below +5°C, more preferably below -5°C.

[0137] The pour point can be measured according to ISO 3016.

[0138] The PAGs represent from 0.05 to 40% by weight, preferably from 0.1 to 30% by weight, preferably from 0.2 to 20% by weight, of the total weight of the lubricating composition (reduced to 100% by weight).

[0139] PAGs are commercially available products. Cellulosic compound

[0140] The lubricating composition according to the invention comprises at least one cellulose compound.

[0141] Preferably, the cellulose compound is chosen from alkylcelluloses, dialkylcelluloses, hydroxyalkylcelluloses, carboxyalkylcelluloses, and mixtures thereof, preferably from hydroxyalkylcelluloses, advantageously said at least one cellulose compound is a hydroxyethylcellulose.

[0142] For the purposes of the present invention, a hydroxyalkylcellulose is distinguished from a carboxyalkylcellulose in particular in that the carboxyalkylcellulose comprises at least one carboxyl function -COOH, whereas the hydroxyalkylcellulose does not comprise a carboxyl function -COOH.

[0143] In the context of the cellulose compound used in the invention, advantageously the alkyl groups possibly present have from 1 to 8 carbon atoms, more preferably from 1 to 4 carbon atoms.

[0144] Advantageously, the lubricating composition comprises hydroxyethylcellulose (HEC) as a cellulose compound.

[0145] According to one embodiment, at least one cellulosic compound of the lubricating composition, preferably all the cellulosic compounds of the lubricating composition, has a weight-average molecular mass of at least 700,000 Da, of preferably ranging from 700,000 to 2,000,000 Da.

[0146] The weight average molecular mass of cellulose compounds can be measured by gel permeation chromatography (“GPC”).

[0147] The cellulose compound(s) represent from 0.005 to 5% by weight, preferably from 0.005 to 3% by weight, preferably from 0.01 to 1% by weight, of the total weight of the lubricating composition (reduced to 100% by weight).

[0148] The cellulose compounds are commercially available and will advantageously be chosen from water-soluble compounds.

[0149] The inventors have in fact discovered that a composition comprising at least two PAGs having different molar masses and a cellulose compound makes it possible to obtain a composition having improved lubrication properties, in particular this association makes it possible to obtain a reduction in the capacity to form residues during washing and an improved capacity for separation with oils. Acid-base anti-corrosion system

[0150] The lubricating composition according to the invention advantageously comprises an acid-base anti-corrosion system.

[0151] When implemented, the anti-corrosion system of the lubricating composition according to the present invention comprises at least one acid and at least one base.

[0152] Among the acids that may be mentioned are aliphatic monocarboxylic acids, in particular having from 4 to 15 carbon atoms, for example octanoic acid, isononanoic acid, neodecanoic acid, aliphatic dicarboxylic acids having from 4 to 15 carbon atoms, for example decanedioic acid (sebacic acid), undecanedioic acid, dodecanedioic acid, isononanedioic acid, and mixtures thereof as well as aromatic acids.

[0153] For the purposes of the present invention, the term “aliphatic acid” or “aliphatic carboxylic acid” means a compound comprising at least one -COOH function and not comprising an aromatic group, and advantageously comprising only carbon, hydrogen and oxygen atoms.

[0154] For the purposes of the present invention, the term “aromatic acid” means an acid comprising at least one aromatic group, optionally of aromatic heterocycle type, and comprising at least one acid function of -COOH type.

[0155] Preferably, at least one acid of the anti-corrosion system is a saturated aliphatic acid.

[0156] Preferably, at least one acid of the anti-corrosion system implemented in the invention consists of carbon, hydrogen and oxygen atoms.

[0157] Preferably, at least one acid is a monoacid. Monoacids in particular make it possible to reduce staining.

[0158] Among the bases that may be mentioned are amines, in particular alkanolamines and amino alcohols, potash and sodium hydroxide. The base(s) may be chosen from potash, sodium hydroxide, and ethanolamines, such as monoethanolamine (MEA), die-ethanolamine (DEA), methyldiethanolamine (MDEA), triethanolamine (TEA), diglycolamine (DGA), isopropanolamines, such as mono-isopropanolamine (MIPA), diisopropanolamine (DIPA) and triisopropanolamine (TIPA), ethylene amines, such as ethylenediamine (EDA), diethylenetriamine (DETA), triethylenetetramine (TETA) and tetraethylenepentamine (TEPA), cyclamines, such as cyclohexylamine, 2-amino-2-ethyl-1,3-propanediol, 2-amino-2-methyl-1-propanol and mixtures thereof.

[0159] According to one embodiment, the base(s) are chosen from monoethanolamine (MEA), diethanolamine (DEA), methyldiethanolamine (MDEA), triethanolamine (TEA), diglycolamine (DGA), isopropanolamines, such as monoisopropanolamine (MIPA), diisopropanolamine (DIPA) and triisopropanolamine (TIPA), ethylene amines, such as ethylenediamine (EDA), diethylenetriamine (DETA), triethylenetetramine (TETA) and tetraethylenepentamine (TEPA), cyclamines, such as cyclohexylamine, 2-amino-2-ethyl-1,3-propanediol, 2-amino-2-methyl-1-propanol and mixtures thereof.

[0160] According to one embodiment, the lubricating composition comprises: - from 0.01 to 20% by weight, preferably from 0.05 to 15% by weight, preferably from 0.05 to 15% by weight, of acid(s), and - from 0.01 to 25% by weight, preferably from 0.01 to 20% by weight, preferably from 0.05 to 20% by weight, of base(s),

[0161] relative to the total weight of the lubricating composition.

[0162] According to one embodiment, the lubricating composition comprises: - from 0.01 to 20% by weight, preferably from 0.05 to 15% by weight, preferably from 0.05 to 15% by weight, of acid(s), at least one acid being an aliphatic acid, and - from 0.01 to 25% by weight, preferably from 0.01 to 20% by weight, preferably from 0.05 to 20% by weight, of amine(s),

[0163] relative to the total weight of the lubricating composition.

[0164] According to a preferred embodiment, the lubricating composition comprises: - from 0.01 to 20% by weight, preferably from 0.05 to 15% by weight, preferably from 0.05 to 15% by weight, of acid(s), at least one acid advantageously being a monocarboxylic acid having from 4 to 15 carbon atoms and at least one acid advantageously being a dicarboxylic acid having from 4 to 15 carbon atoms and - from 0.01 to 25% by weight, preferably from 0.01 to 20% by weight, preferably from 0.05 to 20% by weight of alkanolamine(s), at least one alkanolamine being advantageously chosen from monoethanolamine (MEA), diethanolamine (DEA), methyldiethanolamine (MDEA), triethanolamine (TEA), diglycolamine (DGA), isopropanolamines, such as monoisopropanolamine (MIPA), diisopropanolamine (DIPA) and triisopropanolamine (TIPA), and mixtures thereof,

[0165] relative to the total weight of the lubricating composition.

[0166] According to one embodiment, the acid / base mass ratio of the anti-corrosion system ranges from 0.1 to 2, preferably from 0.2 to 1, more preferably from 0.3 to 0.8.

[0167] Preferably, the anti-corrosion system is chosen so as to maintain the pH of the lubricating composition at an alkaline pH, i.e. a pH ranging from 8 to 11, preferably from 8 to 10.

[0168] When implemented, the acid-base anti-corrosion system represents from 0.1 to 30% by weight, preferably from 0.5 to 30% by weight, preferably from 1 to 30% by weight, of the total weight of the lubricating composition (reduced to 100% by weight). Non-ionic surfactant(s)

[0169] The composition according to the invention may optionally comprise at least one non-ionic surfactant.

[0170] According to one embodiment, the non-ionic surfactant has a hydrophilic-lipophilic balance (HLB) ranging from 7 to 17.

[0171] In the context of the present invention, HLB can for example be measured according to the Griffin method.

[0172] According to one embodiment, the surfactant(s) is(are) chosen from alkoxylated fatty alcohols, sorbitan esters, alkylpolyglycosides, preferably from alkoxylated fatty alcohols, the alkoxylated fatty alcohols preferably being ethoxylated and / or propoxylated fatty alcohols. According to one embodiment, the ethoxylated and / or propoxylated fatty alcohols are chosen from ethoxylated and propoxylated fatty alcohols.

[0173] In the context of the present invention, the expression "alkoxylated fatty alcohol" designates an alcohol comprising an alkyl chain and alkoxy units, for example ethoxy units (-CH2CH2O-) and / or propoxy units (-CH2CH2CH2O- or CH3CH(CH3)O-). The alkyl chain may be linear or branched and may comprise, for example, from 6 to 28 carbon atoms or from 7 to 22 carbon atoms.

[0174] In the context of the present invention, alkoxylated fatty alcohols are different from PAGs.

[0175] Sorbitan esters may include sorbitan monoesters, sorbitan diesters, or sorbitan triesters. Non-limiting examples of sorbitan esters include sorbitan monolaurate, sorbitan monooleate, sorbitan monostearate, sorbitan trioleate, sorbitan tristearate.

[0176] The alkylpolyglycosides may, for example, comprise alkyl chains having from 6 to 20 carbon atoms.

[0177] Preferably, at least one non-ionic surfactant used in the invention is chosen from alkoxylated fatty alcohols, in particular ethoxylated and / or propoxylated fatty alcohols. According to one embodiment, all the non-ionic surfactants of the lubricating composition according to the invention are chosen from alkoxylated fatty alcohols.

[0178] Typically, the alkoxylated fatty alcohols of the lubricating composition are in the form of a mixture of fatty alcohols comprising a distribution of compounds which differ in the number of alkoxylated units.

[0179] According to one embodiment, each alkoxylated fatty alcohol comprises from 1 to 20 alkoxylated units, preferably from 1 to 15 alkoxylated units, the alkoxylated units preferably being chosen from ethoxylated units, propoxylated units and their mixture.

[0180] According to a preferred embodiment, the alkoxylated fatty alcohols used in the lubricating composition according to the invention comprise ethoxylated units, optionally in combination with propoxylated units. Indeed, the ethoxylated units will provide good solubility in water.

[0181] According to one embodiment, each alkoxylated fatty alcohol comprises an aliphatic hydrocarbon chain comprising from 6 to 24 carbon atoms, preferably from 6 to 16 carbon atoms.

[0182] The lubricating composition according to the invention may comprise a mixture of alkoxylated fatty alcohols in which the alkoxylated fatty alcohols differ from each other by the length of the hydrocarbon chain. According to this embodiment, the hydrocarbon chain, preferably of alkyl type, comprises from 7 to 22 carbon atoms, preferably from 12 to 20 carbon atoms.

[0183] According to a preferred embodiment, the molar mass of the alkoxylated fatty alcohols ranges from 130 to 850 g / mol, preferably from 140 to 700 g / mol, more preferably from 150 to 500 g / mol.

[0184] The non-ionic surfactants represent from 0.001 to 15% by weight, preferably from 0.002 to 10% by weight, of the total weight of the lubricating composition (reduced to 100% by weight).

[0185] Non-ionic surfactants, in particular alkoxylated fatty alcohols, are commercially available products. Lubricating composition

[0186] The lubricating composition according to the invention is an aqueous lubricating composition. Water may represent from 30 to 99.99% by weight of the total weight of the lubricating composition.

[0187] When the composition is a ready-to-use composition, the water preferably represents from 60 to 99.99% by weight, preferably from 70 to 99% by weight, of the total weight of the lubricating composition.

[0188] When the composition is a concentrated composition (to be diluted), the water preferably represents from 30 to 90% by weight, preferably from 40 to 80% by weight, of the total weight of the lubricating composition.

[0189] The lubricating composition according to the invention may further comprise at least one additive chosen from the additives conventionally used by those skilled in the art in lubricating compositions for metalworking, preferably at least one additive chosen from anti-foams, biocides, wetting agents, friction modifiers, antifreeze additives, anti-corrosion agents other than acid-base systems, and their mixture.

[0190] According to one embodiment, the lubricating composition according to the invention further comprises at least one additive chosen from anti-foams, anti-corrosion agents of the benzotriazole or tolyltriazole type, and biocides, alone or as a mixture, preferably in a total amount ranging from 0.01 to 15% by weight, preferably from 0.05 to 10% by weight, relative to the total weight of the lubricating composition.

[0191] Advantageously, the lubricating composition according to the invention does not comprise boron compounds.

[0192] Advantageously, the lubricating composition according to the invention does not comprise polyvinylpyrrolidone polymers.

[0193] According to one embodiment, the viscosity at 40°C of the ready-to-use lubricating composition ranges from 1 to 20 mm2 / s, preferably from 1.5 to 5 mm2 / s.

[0194] According to one embodiment, the viscosity at 40°C of the concentrated composition ranges from 50 to 120 mm2 / s, preferably from 60 to 100 mm2 / s.

[0195] The viscosity at 40°C of the lubricating composition can be measured according to ASTM D7042.

[0196] According to one embodiment, the lubricating composition according to the invention comprises water and: - from 0.05 to 30% by weight, preferably from 0.1 to 15% by weight, more preferably from 0.15 to 10% by weight, of PAG1 comprising alkylene oxide units comprising from 2 to 8 carbon atoms, preferably from 2 to 4 carbon atoms, - from 0.01 to 30%, preferably from 0.05 to 15% by weight, more preferably from 0.1 to 10% by weight by weight of PAG2 comprising alkylene oxide units comprising from 2 to 8 carbon atoms, preferably from 2 to 4 carbon atoms, - optionally from 0.01 to 10% by weight, preferably from 0.02 to 7% by weight, more preferably from 0.05 to 5% by weight of PAG3 comprising alkylene oxide units comprising from 2 to 8 carbon atoms, preferably from 2 to 4 carbon atoms, - from 0.005 to 10% by weight, preferably from 0.005 to 5% by weight, preferably from 0.005 to 1% by weight, of cellulose compound(s),

[0197] relative to the total weight of the lubricating composition.

[0198] According to one embodiment, the lubricating composition according to the invention comprises water and: - from 0.05 to 30% by weight, preferably from 0.1 to 15% by weight, more preferably from 0.15 to 10% by weight, of PAG1 having a molar mass ranging from 700 to 1800 g / mol, - from 0.01 to 30%, preferably from 0.05 to 15% by weight, more preferably from 0.1 to 10% by weight by weight of PAG2 having a molar mass ranging from 2000 to 5000 g / mol, - optionally from 0.01 to 10% by weight, preferably from 0.02 to 7% by weight, more preferably from 0.05 to 5% by weight of PAG3 having a molar mass ranging from 700 to 1800 g / mol, - from 0.005 to 10% by weight, preferably from 0.005 to 5% by weight, preferably from 0.005 to 1% by weight, of cellulose compound(s),

[0199] relative to the total weight of the lubricating composition.

[0200] According to one embodiment, the lubricating composition according to the invention comprises water and: - from 0.05 to 30% by weight, preferably from 0.1 to 15% by weight, more preferably from 0.15 to 10% by weight, of PAG1 having a molar mass ranging from 700 to 1800 g / mol, PAG1 being a copolymer comprising ethylene oxide units and propylene oxide units, - from 0.01 to 30%, preferably from 0.05 to 15% by weight, more preferably from 0.1 to 10% by weight by weight of PAG2 having a molar mass ranging from 2000 to 5000 g / mol, PAG2 being a copolymer comprising ethylene oxide units and propylene oxide units, - optionally from 0.01 to 10% by weight, preferably from 0.02 to 7% by weight, more preferably from 0.05 to 5% by weight of PAG3 having a molar mass ranging from 700 to 1800 g / mol, PAG3 being a copolymer comprising ethylene oxide units and propylene oxide units, - from 0.005 to 10% by weight, preferably from 0.005 to 5% by weight, preferably from 0.005 to 1% by weight, of cellulose compound(s) chosen from hydroxyalkylcelluloses where the alkyl groups contain from 1 to 4 carbon atoms,

[0201] relative to the total weight of the lubricating composition.

[0202] According to one embodiment, the lubricating composition according to the invention comprises water and: - from 0.05 to 30% by weight, preferably from 0.1 to 15% by weight, more preferably from 0.15 to 10% by weight, of PAG1 having a molar mass ranging from 700 to 1800 g / mol, PAG1 being a copolymer comprising ethylene oxide units and propylene oxide units and having at least one terminal alkyl group, - from 0.01 to 30%, preferably from 0.05 to 15% by weight, more preferably from 0.1 to 10% by weight of PAG2 having a molar mass ranging from 2000 to 5000 g / mol, PAG2 being a copolymer comprising ethylene oxide units and propylene oxide units, and having at least one terminal hydroxyl group, - optionally from 0.01 to 10% by weight, preferably from 0.02 to 7% by weight, more preferably from 0.05 to 5% by weight of PAG3 having a molar mass ranging from 700 to 1800 g / mol, PAG3 being a copolymer comprising ethylene oxide units and propylene oxide units and having at least one terminal alkyl group, - from 0.005 to 10% by weight, preferably from 0.005 to 5% by weight, preferably from 0.005 to 1% by weight, of cellulose compound(s) chosen from hydroxyalkylcelluloses where the alkyl groups contain from 1 to 4 carbon atoms, - at least 30% by weight of water, preferably at least 40% by weight of water, preferably at least 45% by weight of water, - possibly : • from 0.01 to 10% by weight, preferably from 0.01 to 5% by weight, preferably from 0.05 to 5% by weight, of acid(s), at least one acid being an aliphatic acid, and • from 0.01 to 10% by weight, preferably from 0.01 to 5% by weight, preferably from 0.05 to 5% by weight, of base(s),

[0203] relative to the total weight of the lubricating composition.

[0204] According to one embodiment, the lubricating composition according to the invention comprises water and: - from 0.05 to 30% by weight, preferably from 0.1 to 15% by weight, more preferably from 0.15 to 10% by weight, of PAG1 having a molar mass ranging from 700 to 1800 g / mol, PAG1 being a copolymer comprising ethylene oxide units and propylene oxide units and having at least one terminal alkyl group, - from 0.01 to 30%, preferably from 0.05 to 15% by weight, more preferably from 0.1 to 10% by weight by weight of PAG2 having a molar mass ranging from 2000 at 5000 g / mol, PAG2 being a copolymer comprising ethylene oxide units and propylene oxide units, and having at least one terminal hydroxyl group, - optionally from 0.01 to 10% by weight, preferably from 0.02 to 7% by weight, more preferably from 0.05 to 5% by weight of PAG3 having a molar mass ranging from 700 to 1800 g / mol, PAG3 being a copolymer comprising ethylene oxide units and propylene oxide units and having at least one terminal alkyl group, - from 0.005 to 10% by weight, preferably from 0.005 to 5% by weight, preferably from 0.005 to 1% by weight, of cellulose compound(s) chosen from hydroxyalkylcelluloses where the alkyl groups contain from 1 to 4 carbon atoms, - at least 30% by weight of water, preferably at least 40% by weight of water, preferably at least 45% by weight of water, - possibly : • from 0.01 to 20% by weight, preferably from 0.05 to 15% by weight, of acid(s), at least one acid being an aliphatic acid comprising from 4 to 15 carbon atoms, and • from 0.01 to 25% by weight, preferably from 0.05 to 15% by weight, of alkanolamine(s),

[0205] relative to the total weight of the lubricating composition.

[0206] According to one embodiment, when the composition is a ready-to-use composition, it comprises: - from 0.05 to 15% by weight, preferably from 0.05 to 10% by weight, more preferably from 0.1 to 5% by weight, of a first polyalkylene glycol PAG1, - from 0.05 to 15% by weight, preferably from 0.05 to 10% by weight, preferably from 0.1 to 5% by weight of a second polyalkylene glycol PAG2, it being understood that the ratio between the molar mass of PAG1 and the molar mass of PAG2 is strictly less than 1, - optionally from 0.01 to 5% by weight, preferably from 0.02 to 2% by weight, more preferably from 0.05 to 1% by weight, of a third polyalkylene glycol PAG3, - from 0.005 to 5% by weight, preferably from 0.005 to 1% by weight, preferably from 0.005 to 0.5% by weight, of cellulose compound(s), - at least 60% by weight of water, preferably at least 70% by weight of water, preferably at least 80% by weight of water, - possibly : from 0.01 to 10% by weight, preferably from 0.01 to 5% by weight, of preferably from 0.05 to 5% by weight of acid(s), at least one acid being an aliphatic acid comprising from 4 to 15 carbon atoms, and • from 0.01 to 10% by weight, preferably from 0.01 to 5% by weight, preferably from 0.05 to 5% by weight, of alkanolamine(s),

[0207] relative to the total weight of the lubricating composition.

[0208] According to one embodiment, when the composition is a composition to be diluted (concentrated), it comprises: - from 0.5 to 30% by weight, preferably from 1 to 20% by weight, preferably from 2 to 15% by weight, of a first polyalkylene glycol PAG1, - from 0.5 to 30% by weight, preferably from 1 to 20% by weight, preferably from 2 to 15% by weight, of a second polyalkylene glycol PAG2, it being understood that the ratio between the molar mass of PAG1 and the molar mass of PAG2 is strictly less than 1, - optionally from 0.1 to 15% by weight, preferably from 0.1 to 10% by weight, more preferably from 0.5 to 5% by weight, of a third polyalkylene glycol PAG3, - from 0.05 to 10% by weight, preferably from 0.05 to 5% by weight, preferably from 0.1 to 1% by weight, of cellulose compound(s), - at least 30% by weight of water, preferably at least 40% by weight of water, preferably at least 45% by weight of water, - possibly : • from 0.5 to 20% by weight, preferably from 0.5 to 15% by weight, preferably from 1 to 15% by weight, of acid(s), at least one acid being an aliphatic acid comprising from 4 to 15 carbon atoms, and • from 0.5 to 25% by weight, preferably from 0.5 to 20% by weight, preferably from 1 to 20% by weight, of alkanolamine(s),

[0209] relative to the total weight of the lubricating composition.

[0210] Preferably, the lubricating composition according to the invention is in the form of a solution. Indeed, the ingredients of the lubricating composition are preferably soluble or solubilized in water.

[0211] For the purposes of the present invention, a “solution” is distinguished from an emulsion or a dispersion which may contain several phases or which may contain non-solubilized particles.

[0212] According to one embodiment, the aqueous lubricating composition according to the invention is not an emulsion.

[0213] The lubricating composition according to the invention can be prepared by simply mixing the ingredients, according to any methods known to those skilled in the art to obtain a solution. Applications

[0214] The invention also relates to the use of the lubricating composition according to the invention, as a fluid for metalworking, in particular for machining (turning, milling, drilling, sawing, threading among others), forming, cutting, stamping or even rolling of metal parts, typically steel parts, in particular stainless steel.

[0215] It should be noted that the lubricating composition will advantageously be diluted with water before its use as a metalworking fluid.

[0216] The present invention also relates to a method for lubricating at least one metal surface of a metal part, in particular aluminum or steel, comprising bringing the lubricating composition into contact with said metal surface.

[0217] Preferably, the metal surface is a steel surface.

[0218] It should be noted that the lubrication method may comprise a step of diluting the lubricating composition with water before the step of bringing the lubricating composition (thus diluted) into contact with said metal surface.

[0219] The invention also relates to a metalworking method, comprising at least one metalworking step, preferably chosen from a machining, forming, cutting, stamping or rolling step, carried out on a metal part coated on at least part of its surface with the lubricating composition according to the invention.

[0220] Preferably, the metalworking method comprises at least one preliminary step of lubricating at least a portion of said metal surface, comprising contacting the lubricating composition with at least a portion of said metal surface.

[0221] The inventors have in fact discovered that a composition comprising both a PAG, a non-ionic surfactant and a cellulose compound makes it possible to obtain a composition having improved lubrication properties, in particular this association makes it possible to obtain an improved capacity to be eliminated after the metalworking step.

[0222] The PAGs used in the aforementioned use may have one or more of the characteristics and preferences described above in the context of the lubricating composition according to the invention.

[0223] The cellulosic compound(s) used in the aforementioned use may have one or more of the characteristics and preferences described above in the context of the lubricating composition according to the invention.

[0224] The lubricating composition resulting from the aforementioned use may have one or more of the characteristics and preferences described above within the scope of the com- lubricating position according to the invention.

[0225] The invention also relates to the use of the lubricating composition according to the invention to improve the eco-performance of a process comprising at least one metalworking step, in which the eco-performance is chosen from:

[0226] - the reduction of the energy consumed for the implementation of the process,

[0227] - increasing the productivity of the process,

[0228] - improving the safety of process operators,

[0229] eco-performance being chosen in particular from the improvement of the safety of the process operators.

[0230] The metalworking step may include machining (turning, milling, drilling, sawing, threading among others), forming, cutting, stamping or even rolling of metal parts, the metal preferably being steel.

[0231] In other words, the lubricating composition according to the invention makes it possible to reduce the environmental impact of a process comprising at least one metalworking step. EXAMPLES

[0232] In the remainder of this description, examples are given for the purpose of illustrating the present invention and are not intended in any way to limit its scope.

[0233] Example 1: Preparation of lubricating compositions

[0234] Two lubricating compositions were prepared. The following ingredients were used: - ExPAGl denotes a poly(alkylene glycol) comprising ethylene oxide (EO) and propylene oxide (PO) units in an EO / PO ratio of approximately 1 / 1, ExPAGl being terminated by a butyl group at one end and a hydroxyl group at the other end, ExPAGl having a molecular weight in the range of 900 to 1500 g / mol. - ExPAG2 denotes a poly(alkylene glycol) comprising ethylene oxide (EO) and propylene oxide (PO) units in an EO / PO ratio of approximately 4 / 1, ExPAG2 being terminated by a hydroxyl group at both ends, ExPAG2 having a molecular mass of approximately 2700 g / mol. - ExPAG3 denotes a poly(alkylene glycol) comprising ethylene oxide (EO) and propylene oxide (PO) units in an EO / PO ratio of approximately 1 / 1, ExPAG3 being terminated by a butyl group at one end and a methyl group at the other end, ExPAG3 having a molecular weight of approximately 1400 g / mol. - HEC denotes a hydroxyethylcellulose having a weight-average molecular mass ranging from 700,000 to 1,500,000 Da. - alkanolamine means one or more alkanolamines chosen from monoethanolamine (MEA), diethanolamine (DEA), triethanolamine (TEA), diglycolamine (DGA), monoisopropanolamine (MIPA), diisopropanolamine (DIPA), triisopropanolamine (TIPA), methyldiethanolamine (MDEA), 2-amino-2-ethyl-1,3-propanediol, 2-amino-2-methyl-1-propanol and mixtures thereof. - aliphatic acid means one or more acids chosen from C8-C11 aliphatic monoacids, C8-C11 aliphatic diacids, - aromatic acid means one or more polyacids comprising at least one aromatic cycle, - additive package means a mixture of additives conventionally used in lubricating compositions for metalworking, including in particular an antifoam, a biocide and a benzo-triazole type anticorrosion agent.

[0235] Table 1 gives the details of the compositions tested, the percentages are percentages by weight relative to the total weight of the composition.

[0236] [Tables 1] CCI CC2 Cil CI2 Water qsp qsp qsp qsp ExPAGl 3% 3% 4.5% 4.5% ExPAG2 0 0 3.5% 3.5% ExPAG3 0 0 1.0% 1.0% HEC 0.2% 1% 0.2% 1% Aliphatic acid 9% 9% 9% 9% Aromatic acid 0 0 2.5% 2.5% Alkanolamine 15.0% 15.0% 15.9% 15.9% Additive package 7.93% 7.93% 8.31% 8.31%

[0237] Example 2: Evaluation of the formation of viscous residues

[0238] In this example, the ability of the compositions described in Example 1 to form viscous residues was compared.

[0239] For this test, the composition of Table 1 was diluted in water to 8%.

[0240] The test protocol is as follows with the following successive steps:

[0241] - initial:

[0242] • Pour 10 ml of dilution (8% TH40) into a cup

[0243] • Evaporate to constant weight 80°C (1h45)

[0244] - 1st wash:

[0245] • Pour into a cup with dry extract (ES) of the initial, 10 ml of 8% TH40 dilution

[0246] • Wait 15 min in static mode (no mixing)

[0247] • Drain the excess

[0248] • Evaporate for 15 min at 80°C

[0249] Repeat this step N times until a significant residue is obtained on the reference formula according to the protocol below:

[0250] - N wash:

[0251] • Pour into a cup with ES of the Nl wash, 10 ml of 8% TH40 dilution

[0252] • Wait 15 min in static mode (no mixing)

[0253] • Drain the surplus

[0254] • Evaporate for 15 min at 80°C

[0255] Once this residue is obtained, proceed as follows:

[0256] - washing with pure water:

[0257] • Pour into a cup with ES of the Ninth wash, 10 ml of osmosis water

[0258] • Wait 15 min in static mode (no mixing)

[0259] • Drain the excess

[0260] • Evaporate for 15 min at 80°C

[0261] It was observed that after the final washing with pure water, for the comparative compositions CCI and CC2, residues of polymers and minerals were still present in the cup whereas for the compositions according to the invention Cil and CI2, no residue remained, the cup was clean.

[0262] As the results of this example show, the lubricating composition according to the invention makes it possible to avoid the formation of residues, in particular viscous residues of dry polymer type (whitish deposit), during washing taking place after the metalworking step.

[0263] Example 3: Evaluation of anti-wear and extreme pressure properties

[0264] The compositions described in Example 1 were evaluated in a 4-ball type anti-wear test.

[0265] For this test, the composition of Table 1 was diluted in water to 8%.

[0266] The extreme pressure and anti-wear properties of the lubricating compositions are evaluated by the 4-ball test according to the ASTM D2783 standard adapted with the following parameters:

[0267] - speed close to 1500 rpm,

[0268] - room temperature, i.e. approximately 20°C,

[0269] - 1 minute charging time.

[0270] The extreme pressure measurement is carried out by rotating a stainless steel ball on three stainless steel balls held stationary, the 4 balls being completely covered with a film of lubricant. A load is applied to the balls and gradually increased (every minute according to the above parameters) until the balls weld together. The balls are changed before each increase in load.

[0271] The extreme pressure power corresponds to the value of the load from which the 4 balls weld, preventing the rotation of the upper ball on the other 3. The greater the load, the higher the extreme pressure power.

[0272] This method also makes it possible to evaluate the anti-wear properties of a lubricating composition. During the gradual increase in load, it is possible to determine, at each stage, the wear diameter on the 3 balls. The smaller the wear diameter, the more effective the lubricant is in preventing wear (or seizure) of the parts.

[0273] The wear diameter in mm is shown in Table 2 for different loads

[0274] [Tables2] Load CCI CC2 Cil CI2 100 kg 1.2 1.4 0.9 1 120 kg 1.4 1.6 1.1 1.2 140 kg 1.7 1.9 1.3 1.5 160 kg weld weld 1.4 1.65 180 kg weld weld

[0275] As shown by the results in Table 2, the composition according to the invention C11 has a smaller wear diameter and a higher weld load and therefore better anti-wear and extreme pressure properties than the composition outside the invention CCI. Similarly, the composition according to the invention CI2 has a smaller wear diameter and a higher weld load and therefore better anti-wear and extreme pressure properties than the composition outside the invention CC2. Thus, with an iso-cellulose content, the composition according to the invention comprising two PAGs of different mass makes it possible to improve the anti-wear and extreme pressure properties.

[0276] Example 4: Evaluation of the capacity to release oils

[0277] In this example, the CCI and Cil compositions described in Table 1 are evaluated and compared for their ability to release oils.

[0278] For this test, the composition of Table 1 was diluted in water to 10%.

[0279] The test protocol is as follows:

[0280] The diluted composition was mixed with an oil in a proportion: 90% by volume of composition and 10% by volume of oil.

[0281] The principle is to mix 10% of oil called foreign oil in 90% of a solution of the formula diluted to 8% in hard water TH 40 (French degree).

[0282] At the initial moment, the presence of unmixed oil on the surface is checked, then it is stirred vigorously by hand and the evolution of the decantation of the oil is observed after 15 min, 30 min, 1 h, 2 h and 24 h.

[0283] The composition according to the invention Cil exhibits a better separation between the aqueous phase and the oily phase than the composition CCI. Indeed, it has been observed that after decantation of the composition CCI, the aqueous phase is polluted by the oil, whereas after decantation of the composition Cil, the aqueous phase is separated from the oil, as initially, without pollution, with rapid kinetics.

Claims

Claims

1. Lubricating composition comprising water and: - from 0.05 to 40% by weight of at least two polyalkylene glycols PAG1 and PAG2, the ratio between the molar mass of PAG1 and the molar mass of PAG2 being strictly less than 1. - from 0.001 to 30% by weight of at least one cellulose compound, relative to the total weight of the lubricating composition.

2. Lubricating composition according to claim 1, in which the ratio between the molar mass of PAG1 and the molar mass of PAG2 is less than or equal to 0.8, preferably less than or equal to 0.7, more preferably less than or equal to 0.

5.

3. Lubricating composition according to claim 1 or 2, in which the molar mass of PAG1 ranges from 500 to 2000 g / mol, preferably from 700 to 1800 g / mol, and / or the molar mass of PAG2 ranges from 1500 to 5000 g / mol, preferably from 2000 to 4000 g / mol, it being understood that the ratio between the molar mass of PAG1 and the molar mass of PAG2 is strictly less than 1.

4. Lubricating composition according to any one of claims 1 to 3, further comprising a third polyalkylene glycol PAG3, said PAG3 preferably having a molar mass ranging from 500 to 2000 g / mol, preferably from 700 to 1800 g / mol, PAG3 having a molar mass different from PAG1 and different from PAG2, PAG3 preferably having at least one methyl end, advantageously one methyl end and one butyl end.

5. Lubricating composition according to any one of claims 1 to 4, comprising: - from 0.05 to 30% by weight, preferably from 0.1 to 15% by weight, more preferably from 0.15 to 10% by weight, of PAG1, - from 0.01 to 30%, preferably from 0.05 to 15% by weight, more preferably from 0.1 to 10% by weight of PAG2, - optionally from 0.01 to 10% by weight, preferably from 0.02 to 7% by weight, more preferably from 0.05 to 5% by weight of PAG3, relative to the total weight of the lubricating composition.

6. Lubricating composition according to any one of claims 1 to 5, further comprising at least one anti-corrosion system comprising at least one acid and at least one base, at least one base preferably being chosen from amines, advantageously from alkanolamines.

7. Lubricating composition according to any one of claims 1 to 6, wherein said at least one cellulose compound is chosen from alkylcelluloses, dialkylcelluloses, hydroxyalkylcelluloses, carboxyalkylcelluloses, and mixtures thereof, preferably from hydroxyalkylcelluloses, advantageously said at least one cellulose compound is a hydroxyethylcellulose.

8. Lubricating composition according to any one of claims 1 to 7, in which the polyalkylene glycol(s) are chosen from poly(ethylene glycol), poly(propylene glycol), copolymers comprising ethylene oxide units and propylene oxide units, and mixtures thereof, preferably from block copolymers comprising ethylene oxide units and propylene oxide units and mixtures thereof, more preferably from ethylene oxide-propylene oxide diblock copolymers and propylene oxide-ethylene oxide-propylene oxide triblock copolymers and mixtures thereof.

9. Lubricating composition according to any one of claims 1 to 8, said composition being a ready-to-use composition comprising water and: - from 0.05 to 15% by weight, preferably from 0.05 to 10% by weight, preferably from 0.1 to 5% by weight, of polyalkylene glycol, - from 0.005 to 5% by weight, preferably from 0.005 to 1% by weight, preferably from 0.005 to 0.5% by weight, of at least one cellulose compound, relative to the total weight of the lubricating composition.

10. A lubricating composition according to any one of claims 1 to 8, said composition being a concentrated composition comprising water and: - from 0.5 to 30% by weight, preferably from 1 to 20% by weight, preferably from 2 to 15% by weight, of polyalkylene glycol, - from 0.05 to 10% by weight, preferably from 0.05 to 5% by weight, preferably from 0.1 to 1% by weight of at least one cellulose compound, relative to the total weight of the lubricating composition.

11. A lubricating composition according to any one of claims 1 to 9, said composition being a ready-to-use composition comprising: - from 0.05 to 15% by weight, preferably from 0.05 to 10% by weight, more preferably from 0.1 to 5% by weight, of a first polyalkylene glycol PAG1, - from 0.05 to 15% by weight, preferably from 0.05 to 10% by weight, preferably from 0.1 to 5% by weight of a second polyalkylene glycol PAG2, it being understood that the ratio between the molar mass of PAG1 and the molar mass of PAG2 is strictly less than 1, - optionally from 0.01 to 5% by weight, preferably from 0.02 to 2% by weight, more preferably from 0.05 to 1% by weight, of a third polyalkylene glycol PAG3, - from 0.005 to 5% by weight, preferably from 0.005 to 1% by weight, preferably from 0.005 to 0.5% by weight, of cellulose compound(s), - at least 60% by weight of water, preferably at least 70% by weight of water, preferably at least 80% by weight of water, - possibly : • from 0.01 to 10% by weight, preferably from 0.01 to 5% by weight, preferably from 0.05 to 5% by weight, of acid(s), at least one acid being an aliphatic acid, and • from 0.01 to 10% by weight, preferably from 0.01 to 5% by weight, preferably from 0.05 to 5% by weight, of base(s), relative to the total weight of the lubricating composition.

12. A lubricating composition according to any one of claims 1 to 8 or 10, said composition being a concentrated composition comprising: - from 0.5 to 30% by weight, preferably from 1 to 20% by weight, preferably from 2 to 15% by weight, of a first polyalkylene glycol PAG1, - from 0.5 to 30% by weight, preferably from 1 to 20% by weight, preferably from 2 to 15% by weight, of a second polyalkylene glycol PAG2, it being understood that the ratio between the molar mass of PAG1 and the molar mass of PAG2 is strictly less than 1, - optionally from 0.1 to 15% by weight, preferably from 0.1 to 10% by weight, more preferably from 0.5 to 5% by weight, of a third polyalkylene glycol PAG3, - from 0.05 to 10% by weight, preferably from 0.05 to 5% by weight, preferably from 0.1 to 1% by weight, of cellulose compound(s), - at least 30% by weight of water, preferably at least 40% by weight of water, preferably at least 45% by weight of water, - possibly : • from 0.5 to 20% by weight, preferably from 0.5 to 15% by weight, preferably from 1 to 15% by weight, of acid(s), at least one acid being an aliphatic acid, and • from 0.5 to 25% by weight, preferably from 0.5 to 20% by weight, preferably from 1 to 20% by weight, of base(s), relative to the total weight of the lubricating composition.

13. A lubricating composition according to any one of claims 1 to 12, wherein: - the first polyalkylene glycol PAG1 is a copolymer comprising ethylene oxide units and propylene oxide units and having a molar mass ranging from 500 to 2000 g / mol, PAG1 having at least one alkyl terminal group having from 1 to 5 carbon atoms, and - the second polyalkylene glycol PAG2 is a copolymer comprising ethylene oxide units and propylene oxide units and having a molar mass ranging from 1500 to 5000 g / mol, PAG2 having two hydroxyl end groups, it being understood that the ratio between the molar mass of PAG1 and the molar mass of PAG2 is strictly less than 1, and - where applicable, the third polyalkylene glycol PAG3 is a co

14.

15. polymer comprising ethylene oxide units and propylene oxide units and having a molar mass ranging from 500 to 2000 g / mol, PAG3 having a molar mass different from PAG1, PAG3 having at least one alkyl terminal group having from 1 to 5 carbon atoms, and - the cellulose compound is a hydroxyethylcellulose. Use of the lubricating composition according to any one of claims 1 to 13, as a fluid for metalworking, in particular for machining, forming, cutting, stamping or rolling of metal parts, the metal preferably being steel. Use of a lubricating composition according to any one of claims 1 to 14, for improving the eco-performance of a process comprising at least one metalworking step, in which the eco-performance is chosen from: - reduction of the energy consumed for the implementation of the process, - increasing the productivity of the process, - improving the safety of process operators, preferably among the improvement of the safety of the process operators.