DE68917816T2 - Additive for oils for cold rolling metals. - Google Patents

Description

The present invention relates to the use of a compound obtainable by reacting at least one member selected from the group consisting of polyalkylenepolyamines and polyalkyleneimines, each containing 3 to 200 nitrogen atoms, with at least one member selected from the group consisting of fatty acid compounds, glycidyl ether compounds and epoxy compounds, as an additive for cold rolling oils and the use of the above-described compound in a cold rolling oil composition.

The cold rolling oil mainly used today is generally based on an animal or vegetable oil, a mineral oil, a fatty acid ester or the like as a lubricating oil component and contains as additional components a rust inhibitor, an extreme pressure agent, an oil improver, an antioxidant, an antifoaming agent and/or other auxiliary agents. Such a cold rolling oil is emulsified with an emulsifier to form an O/W emulsion, which is then supplied to the roll assembly of a rolling mill generally at a concentration of about 1 to 20%. On the other hand, with recent advances in rolling technology, high-speed rolls and rolls for mass production have been introduced, and accordingly, there is a demand for a rolling oil having improved lubricating properties, improved processability and improved disposal suitability.

Under these circumstances, in the prior art cold rolling oil comprising a conventional emulsifier, the roll slipperiness is controlled by adjusting the type and amount of emulsifier added, so as to reduce the amount of oil (scaling) deposited on the surface of the rolling work. is used, with the result that the amount of scaling and the stability of the circulated emulsion cannot be made to match. In other words, the higher the stability of the emulsion, the smaller the amount of scaling on the rolled work, resulting in insufficient lubricating effect. On the other hand, if an attempt is made to increase the amount of scaling, the stability of the emulsion is sacrificed, so that various problems occur while the emulsion is circulated. Furthermore, iron particles formed in the course of cold rolling penetrate into the unstable emulsion, so that there is a risk of sludge adhering to the cold-rolled steel sheet, thereby affecting subsequent washing and tempering processes. Furthermore, the sludge adheres to the rolls and equipment around the rolls, thereby deteriorating the working environment and disturbing workability. In order to overcome these disadvantages, a number of oil compositions for cold rolling have been proposed (eg, JP-B-62-14599 and JP-A-62-121792). However, these compositions are always deficient in preventing the formation of residues (antifouling properties) during tempering and in ensuring the cleanliness of the roll stand, and therefore are not of great utility in practical use.

US-A-4 705 643 relates to a lubricating oil composition comprising a detergent additive which is the hydrolyzed reaction product of an aliphatic branched carboxylic acid having 16 to 20 carbon atoms and a polyamine having at least 3 amine groups. The lubricating oil composition described therein is used in the field of fuel/oil mixtures, in particular in two-stroke internal combustion engines.

A composition comprising, alone or in combination, polyamides obtained by reacting specific polyalkylenediamines with specific fatty acids such as linoleic acid is described in FR-A 1 318 311. This composition can be used in lubricants and fuels for internal combustion engines.

Summary of the invention

The invention relates, in one aspect, to the use of a compound obtainable by reacting at least one member of the group consisting of polyalkylenepolyamines and polyalkyleneimines, each containing 3 to 200 nitrogen atoms, with at least one member of the group consisting of fatty acid compounds, glycidyl ether compounds and epoxy compounds, as an additive for cold rolling oils, and, in another aspect, to the use of the above-described compound in a cold rolling oil composition which exhibits excellent lubricity, emulsion stability and resistance to residue formation during tempering and ensures the utmost cleanliness of the roll stand.

Detailed Description of the Preferred Embodiments

The polyalkylenepolyamines that can be used in the present invention include, among others, diethylenetriamine, triethylenetetramine, tetraethylenepentamine, pentaethylenehexamine, dipropylenetriamine and tetrapropylenepentamine. The polyalkyleneimines include polyethyleneimine, polypropyleneimine and the like.

The fatty acid compounds that react with the active hydrogen atoms of such polyalkylenepolyamines and polyalkyleneimines include, among others, higher fatty acids having 8 to 22 carbon atoms, such as 2-ethylhexylic acid, lauric acid, stearic acid, coconut oil fatty acid, beef tallow fatty acid, oleic acid, linoleic acid and the like, as well as dimer and polymer acids of unsaturated fatty acids, such as oleic acid, linoleic acid, linolenic acid and the like.

The glycidyl ether compounds which react with the active hydrogen atoms of the polyalkylenepolyamines and polyalkyleneimines include, among others, the glycidyl ethers of aliphatic alcohols or alkylphenols, such as octyl alcohol glycidyl ether, lauryl alcohol glycidyl ether, stearyl alcohol glycidyl ether, nonylphenol glycidyl ether, dodecylphenol glycidyl ether and the like.

The epoxy compounds include, but are not limited to, C8-26 aliphatic α-olefin epoxides, C8-22 cycloolefin epoxides, C8-20 alkyl diepoxides, and the like.

The compound used as an additive for oils for cold rolling metals is a compound obtainable by reacting at least one member selected from the group consisting of the above-mentioned polyalkylenepolyamines and polyalkyleneimines each containing 3 to 200 nitrogen atoms with at least one member selected from the group consisting of the above-mentioned fatty acid compounds, glycidyl ether compounds and epoxy compounds, and which acts as a basic surfactant.

In carrying out the invention, the above-mentioned basic compound may be used alone, but it is preferably used in combination with an acidic surfactant such as a phosphoric acid ester compound, a sulfonic acid compound, a sulfonic acid ester compound and the like in the form of a neutral salt at a pH of 3 to 10.

The above-mentioned phosphoric acid ester compounds include, among others, the compounds obtainable by reacting 2 to 5 moles of the adduct of 1 to 30 moles of ethylene oxide to an alkylphenol such as butylphenol, nonylphenol, dodecylphenol and the like, or a higher alcohol such as octyl alcohol, lauryl alcohol, oleyl alcohol and the like, with 1 mole of phosphoric anhydride generally at a temperature of 30 to 90°C, or the compounds obtainable by reacting 2 to 5 moles of the block adduct or random adduct of 1 to 10 moles of propylene oxide and 1 to 30 moles of ethylene oxide to the alkylphenol or the higher alcohol with 1 mole of phosphoric anhydride generally at a temperature of 30 to 90°C.

As examples of the sulfonic acid compounds or sulfonic acid ester compounds, there can be mentioned the compounds obtained by reacting 1 to 2 moles of an alkylbenzene having 6 to 24 carbon atoms, an α-olefin having 8 to 26 carbon atoms, an alkylphenol having 6 to 24 carbon atoms, a higher alcohol having 6 to 22 carbon atoms, or an alkylphenol or higher alcohol-alkylene oxide adduct with 1 mole of a sulfonating agent such as sulfuric acid, fuming sulfuric acid, sulfuric anhydride, chlorosulfonic acid, sulfamic acid or the like, at a temperature of 10 to 120 ° C. As examples of the alkylphenol or higher alcohol-alkylene oxide adduct, there can be mentioned the block adduct or the random adduct obtainable by adding 1 to 30 moles of ethylene oxide or 1 to 10 moles of propylene oxide plus 1 to 30 moles of ethylene oxide.

The basic compound and a neutral salt thereof, which constitute the above-mentioned additive for cold rolling oils, can be synthesized in a known manner. For example, they can be prepared according to the following method. To tetraethylenepentamine (containing 5 nitrogen atoms) is added stearic acid, and the mixture is subjected to condensation with elimination of water at an elevated temperature of 120 to 180°C to obtain an amide compound. To this is added polyoxyethylene nonylphenol ether phosphate or sulfonate at a temperature of 30 to 100°C to obtain a neutral salt having a pH of 7.

In addition, the compound used as an additive for cold rolling oils in the present invention preferably further contains a nonionic surfactant having an HLB number of not less than 6. As examples of such a nonionic surfactant, there can be mentioned the adducts of ethylene oxide, propylene oxide, butylene oxide or the like with C₈₋₂₂ alcohols, alkylphenols, fatty acids or polyhydric alcohol-fatty acid esters. If the HLB number is less than 6, the stability of the emulsion is not satisfactory and the occurrence of oil stains is increased. The above-mentioned C₈₋₂₂ alcohols include octyl alcohol, lauryl alcohol, stearyl alcohol, oleyl alcohol and the like. The alkylphenols include, among others, butylphenol, Octylphenol, nonylphenol, dodecylphenol and the like, and the corresponding condensates with formaldehyde. The fatty acids include lauric acid, myristic acid, palmitic acid, stearic acid, oleic acid and the like. The polyhydric alcohol fatty acid esters include, among others, esters which are obtainable by reacting the fatty acids with glycerin, polyglycerin, pentaerythritol, sorbitol, ethylene glycol, propylene glycol or the like.

The above-mentioned oil composition comprises the above-mentioned compound to be used as an additive in the present invention and a lubricating oil component. With regard to this lubricating oil component, any of the components heretofore used in this type of rolling oil can be used. As examples of such components, animal oils, vegetable oils, mineral oils and synthetic fatty acid esters can be mentioned. These oil components can be used alone or in combination. To be specific, any of the mineral oils such as spindle oil, machine oil, turbine oil, cylinder oil and the like; animal and vegetable oils such as sperm oil, beef tallow, lard, rapeseed oil, castor oil, rice oil, soybean oil, palm oil, coconut oil and the like; esters of fatty acids of beef tallow, coconut oil, castor oil and the like with aliphatic monohydric alcohols having 1 to 22 carbon atoms; and fatty acid esters synthesized from such fatty acids and polyhydric alcohols such as propylene glycol, pentaerythritol, sorbitol and the like.

In general, the oil composition for rolling is based on an animal or vegetable oil, a mineral oil or a synthetic fatty acid ester and optionally contains as an additional component one or more members of the group consisting of oil improvers, extreme pressure additives, rust inhibitors, antioxidants, emulsifiers, antifoaming agents and the like, and is used diluted with water in an emulsion with a concentration of 0.1 to 10%. The oil composition for cold rolling can be used in the same way. The Thus, the compound to be used as an additive according to the invention is first dissolved in an oil component as a base and then diluted with water to form an emulsion. Alternatively, the compound to be used as an additive according to the invention may be first dissolved in water and then emulsified with the oil component as a base to form an emulsion. The amount of the compound to be used as an additive according to the invention added, based on the total weight of the oil composition for cold rolling, is 0.1 to 10 wt% and preferably 0.5 to 5 wt%.

In addition to the above components, the oil composition for cold rolling may optionally further contain any of the known oil improvers, extreme pressure additives, rust inhibitors, antioxidants, defoaming agents and the like.

In the cold rolling oil composition, since the protective colloid effect of the additive of the present invention allows the oil to be stably dispersed in water in fairly large particles, the oil component maintains a stable and fairly large particle size distribution even under agitated conditions with high shear forces in a tank, a circulating pump, and the like.

In addition, since the large oil particles form a thick lubricating film on the metal workpiece when fed to the rolls, the composition exhibits excellent lubricating properties during cold rolling and ensures satisfactory circulation stability (the large particle size of the oil is maintained and no separation of the oil occurs even when the composition is circulated).

Furthermore, when the neutral salt of a basic surfactant and an acidic surfactant is used, its ability to be rapidly adsorbed to the liquid and solid particles to make them hydrophilic helps to eliminate the capture of intruded dirty oil or contaminants such as metal dust during rolling operations and to to prevent residue formation in the tank and on the roll stand. These effects are not achieved with conventional rolling oil compositions prepared by using conventional emulsifiers. Accordingly, the composition obtained by using the compound to be used as an additive for cold rolling oils according to the invention has the advantageous feature of helping to ensure a clean environment, which has not been achieved with conventional cold rolling oil emulsions. Furthermore, since the rolling oil composition obtained by using the compound to be used as an additive for cold rolling oils according to the invention maintains stable lubricating properties during cold rolling, it is far superior to commercial rolling oil compositions heretofore available in terms of lubricating properties and clean roll stand characteristics.

By thus providing the use of a compound as an additive for cold rolling oils which can be used in a cold rolling oil composition having excellent lubricating properties in cold rolling and stable recirculation properties, the present invention makes a significant contribution to the advancement of rolling technology.

The following examples and comparative examples are intended only to illustrate the invention and should not be misunderstood as limiting the scope of the invention.

The use of compounds as additives A to T incorporated into rolling oil compositions according to the present invention is shown in Tables 1 and 2. The thus obtained rolling oil compositions prepared using these additives in predetermined proportions (by weight) are shown in Tables 3 and 4.

The performance properties of these rolling oil compositions were evaluated by the following tests. The results are shown in Tables 5 and 6.

(1) Lubricity test

Using a Timken tester, the test was carried out in accordance with JIS K 2519. That is, in a tank, each of the rolling oil compositions was diluted with water to a concentration of 5% and stirred by a homomixer at 8000 rpm to provide a dispersion at a temperature of 60ºC, and this dispersion was fed to the circulation system. The evaluation was carried out on the basis of the specific area within the seizure limit curves. The worst evaluation was 1.0 (ratio). The larger this ratio, the more favorable the lubricating properties.

(2) Test for prevention of residue formation during tempering

To 5% aqueous dispersions of each oil composition for rolling was added 0.1% iron powder (particle size: not more than 1 µm) to provide an oil dispersion for rolling at 60°C. Using a gear pump, this oil dispersion for rolling was sprayed from a nozzle against a surface of a test steel sheet (0.5 1/min, 1 atm, 5 seconds) and dried. Two steel sheets treated in a similar manner were superimposed, pressed together with a pressure of 40 kg/cm2 and heated at 130°C for 15 hours. Then, the assembly was annealed in an atmosphere of N₂ + 5% H₂ in an annealing furnace at 700°C for 2 hours, and the degree of residue formation on the surface of the steel sheets was visually evaluated and ranked according to the criteria below.

: clean condition without deposits

o : clean condition, but minor deposits are found

x : poor condition with many deposits

(3) Dispersion stability test

To a 5% aqueous dispersion of each of the oil compositions for rolling was added 0.1% of iron powder (particle size: not more than 1 µm) to provide an oil dispersion for rolling at 60°C. Using a gear pump, this dispersion was continuously sprayed at a pressure of 2.5 kg/cm2 against an iron roller heated to 150°C in a closed liquid circuit. After 48 hours, the oil fraction of the dispersion excluding the oil phase floating on the surface was quantitatively determined and the percentage decrease from the initial concentration was determined according to the following equation:

Decrease (%) = [(initial concentration - final concentration)/final concentration] x 100

(4) Test for disposal of the effluent

To the oil dispersion for rolling prepared in the above test (1) was added 3 g of aluminum sulfate, and the mixture was stirred for 2 minutes. After adjusting the pH to 7.0 with Ca(OH)₂, the mixture was further stirred for 10 minutes and then allowed to stand for 30 minutes. The oil phase was discarded, and the clear liquid was collected and analyzed for COD (chemical oxygen demand, KMnO₄ method). Table 1 Additive Basic surface-active component (a) Acid surface-active component (b) Molar mixing ratio (a:b) Tetraethylenepentamine-coconut oil fatty acid monoamide Hexaethyleneheptamine-oleic acid monoamide Polyethylenimine (30 N atoms)-beef tallow fatty acid diamide Diethylenetriamine-2-ethylhexyl acid monoamide Polyethylenimine (150 N atoms)-stearic acid triamide Pentaethylenehexamine-lauric acid monoamide Tetraethylenepentamine-octyl alcohol glycidyl ether (1 mol) adduct Polyethylenimine (50 N atoms)-dodecylolefin epoxide (5 mol) adduct Tetraethylenepentamine-oleic acid dimer monoamide Polyethylenimine (30 N atoms)-oleic acid hexamide Tetraethylenepentamine-octadecylolefin epoxide (2 mol) adduct Polyoxyethylenenonylphenol ether (EO: 8 Mol)-phosphoric acid diesters Polyoxyethylene oleyl ether (EO: 10 Mol)-phosphoric acid diesters Polyoxypropylene/polyoxyethylene oleyl ether (PO: 5 Mol, EO: 15 Mol)-phosphoric acid diesters Polyoxyethylene dodecylphenol ether (EO: 5 Mol)-phosphoric acid diesters Polyoxyethylene nonylphenol ether (EO: 3 Mol)-phosphoric acid monoesters Polyoxyethylene stearyl ether (EO: 12 Mol)-phosphoric acid monoesters Polyoxyethylene 2-ethylhexyl alcohol ether (EO: 7 Mol)-phosphoric acid diesters Polyoxyethylene nonylphenol ether (EO: 20 Mol)-phosphoric acid diesters not used * EO: ethylene oxide PO: propylene oxide Table 2 Additive Basic surface-active component (a) Acid surface-active component (b) Molar mixing ratio (a:b) Tetraethylenepentamine-oleic acid monoamide Polyethylenimine (20 N atoms)-coconut oil fatty acid diamide Hexaethyleneheptamine-beef tallow fatty acid monoamide Diethylenetriamine-2-ethylhexylic acid monoamide Pentaethylenehexamine-stearic acid monoamide Polyethylenimine (150 N atoms)-lauric acid triamide Tetraethylenepentamine-nonylphenol glycidyl ether (1 mol) adduct Polyethylenimine (50 N atoms)-dodecylolefin epoxide (4 mol) adduct Hexaethyleneheptamine-oleic acid dimer monoamide Dodecylbenzenesulfonic acid 1-dodecenesulfonic acid Nonylphenolsulfonic acid Lauryl alcohol sulfonate Polyoxyethylene nonylphenol ether (EO: 10 mol) sulfonate Polyoxyethylene octyl ether (EO: 8 mol) sulfonate Polyoxypropylene/polyoxyethylene stearyl ether (PO: 5 mol, EO: 20 mol) sulfonate Polyoxyethylene/polyoxypropylene nonylphenol ether (PO: 8 mol, EP: 25 mol) sulfonate Octyl alcohol sulfonate * EO: ethylene oxide PO: propylene oxide Table 3 Example (parts by weight) Lubricating oil component purified beef tallow palm oil beef tallow fatty acid butyl ester Additive non-ionic surfactant with an HLB number of not less than 6* Antioxidant 2,6-di-tert-butyl-p-cresol *: U = polyoxyethylene nonylphenol ether (EO: 6 mol) V = polyoxyethylene oleyl ether (EO: 7 mol) W = polyoxyethylene lauryl ether (EO: 5 mol) Table 4 Example Comparative example (parts by weight) Lubricating oil component purified beef tallow palm oil beef tallow fatty acid butyl ester Additive non-ionic surfactant with an HLB number of not less than 6* Antioxidant 2,6-di-tert-butyl-p-cresol *: U = polyoxyethylene nonylphenol ether (EO: 6 mol) V = polyoxyethylene oleyl ether (EO: 7 mol) W = polyoxyethylene lauryl ether (EO: 5 mol) Table 5 Lubricating properties Prevention of residue formation during tempering Dispersion stability (%) Example Table 6 Lubricating properties Prevention of residue formation during tempering Dispersion stability (%) Example Comparative example

It is apparent from Tables 5 and 6 that the use of a compound obtainable as defined in the claims as an oil composition for cold rolling according to the present invention is superior to conventional compositions (comparative examples) in terms of lubricating properties, prevention of residue formation during tempering, dispersion stability and possibility of disposal of the effluent.

Claims (9)

1. Use of a compound as an additive for cold rolling oils, which is obtainable by reacting at least one member selected from the group consisting of polyalkylenepolyamines and polyalkyleneimines, each containing 3 to 200 nitrogen atoms, with at least one member selected from the group consisting of fatty acid compounds, glycidyl ether compounds and epoxy compounds. 2. Use according to claim 1, wherein the fatty acid compound is at least one compound selected from the group consisting of higher fatty acids having 8 to 22 carbon atoms, dimer acids of unsaturated fatty acids and polymeric acids of unsaturated fatty acids. 3. Use according to claim 1 or 2, wherein the glycidyl ether compound is at least one compound selected from the group consisting of glycidyl ethers of aliphatic alcohols and glycidyl ethers of alkylphenols. 4. Use according to any one of claims 1 to 3, wherein the epoxy compound is at least one compound selected from the group consisting of aliphatic α-olefin epoxides having 8 to 26 carbon atoms, cycloolefin epoxides having 8 to 22 carbon atoms and alkyl diepoxides having 8 to 22 carbon atoms. 5. Use according to one of claims 1 to 4, wherein an acidic surface-active component is additionally contained. 6. Use according to claim 5, wherein the acidic surface-active component is at least one compound selected from the group consisting of phosphoric acid ester compounds, sulfonic acid compounds and sulfonic acid ester compounds. 7. Use according to one of claims 1 to 4, wherein a non-ionic surface-active component with an HLB number of not less than 6 is additionally contained. 8. Use according to claim 5 or 6, wherein a non-ionic surface-active component with an HLB number of not less than 6 is additionally included. 9. Use according to any one of claims 1 to 8 in a cold rolling oil composition, wherein the lubricating oil component is at least one component selected from the group consisting of animal and vegetable oils and fats, mineral oils and synthetic fatty acid esters.