DESC:

FORM-2
THE PATENTS ACT, 1970 (39 of 1970)
&
THE PATENTS RULES, 2003

COMPLETE SPECIFICATION
(See section 10 and rule 13)

TITLE

LUBRICANTS AND A PROCESS TO PREPARE THE SAME;

APPLICANT

HINDALCO INDUSTRIES LIMITED,
of address
AHURA CENTRE, 1ST FLOOR, B-WING, MAHAKALI CAVES ROAD, ANDHERI (EAST), MUMBAl-400 093

COMPLETE SPECIFICATION
The following specification particularly describes this invention and the manner in which it is to be performed:

FIELD OF THE INVENTION
[1] The present invention relates to lubricants for edge trimming application of aluminum and its alloys and a process to prepare the same.

BACKGROUND OF THE INVENTION
[2] Aluminium rolled products are produced in two ways, one with Continuous Casting (CC) route and the other with Direct Chilling (DC) route.

[3] In CC route, the molten aluminium alloy is casted continuously to 5-8 mm thickness directly. The temperature of metal during casting at lauder varies between 700°C and 750° C based on alloy composition. Cast sheet from CC is further rolled in cold rolling mill to get desired thickness. Aluminium sheet produced by CC route, prior to edge trimmer operation has uneven edges. The uneven edges have cracks and cuts. If these uneven edges are not trimmed at caster itself, cracks/cuts on the edge get propagated inside the sheet during cold rolling. Propagated cuts/cracks at edges results in sheet breakage and marks on rolls. Sheet breakage can lead to fire at cold mills.

[4] Hence, edge trimming operation just after casting of aluminum sheet is very important. In market, various edge trimmer tools with different geometries, material of construction and lubrication systems are available. Thickness of casted aluminum sheet varies between 5 and 8 mm and temperature varies between 300°C and 400°C. Uneven edges of casted sheet are trimmed by trimming tool (cutter) with the help of lubricant. Quality of lubricant decides the quality of edges. Quality of trimmed edges is very critical in further rolling process and quality of products. Quality of lubricant also decides the edge trimming tool life.

[5] Aluminum being softer and malleable as compared with ferrous material, regular neat cutting lubricants used for metal working are not suitable for edge trimming application. Continuous casting itself is a specialized process followed by edge trimming, where lubrication regime is boundary lubrication. Insufficient lubrication during trimming will result in metal pick up by trimmer blades and excess lubrication will result in stains on aluminum sheet refusal. Apart from that, different alloys of aluminium have different hardness and different mechanical properties; usually all these alloys are cast on same caster and hence, properties of lubricant for edge trimming needs to be optimized in such way that it can accommodate all alloys (from soft to harder)

[6] Purpose of using specialized edge trimming lubricant during trimming operation at continuous caster is to

• Improve the quality of the product
• Provide the cooling to Trimmer blades
• Protect the edge trimmer blades from wearing
• Increase the productivity
• Clean the surface from aluminum fines and aluminum oxide fines generated during trimming
• Corrosion protection to the product

[7] Ordinary, neat metalworking fluids are in-appropriate for edge trimming operation at continuous caster as they cause stains on aluminum sheet, burrs at the edges, patchy surface and have many other defects. Hence, aluminum industries, specialty neat oils are used for intended application. Usually, the lubricant is used in neat form with mist lubrication system.

[8] EP 0 690 121 discloses a lubricant for use in a metal forming process. The lubricant comprises a mixture of mineral spirits and one or more compounds selected from the group consisting of polyisobutenes having a molecular weight of from 320 to 460 and alkylene glycols having one terminal hydroxyl group and a viscosity in the range of from 65 to 1715 Saybolt Universal Seconds (SUS) at 100 °C. We are told that the selected organic compounds evaporate leaving a small trace of residue that may be removed using water based cleaning agents.

[9] EP 0 690 121 acknowledges prior art lubricants made of mineral oil that have excellent lubricating properties. The mineral oil remains as a residual coating on the fins after the fin stamping operation and it needs to be removed before subsequent manufacturing operations.

[10] EP 0690 121 also acknowledges prior art lubricants comprising mineral spirits with small amounts of surfactants and lubricity enhancement agents. Although these lubricants evaporate without leaving a residue, their lubricating performance is very poor. These lubricants are also volatile organic compounds.

[11] CN104818091A recites an aluminum alloy cutting liquid comprises 5-10 pts. fatty acid diethanolamide, 3-5 pts. sorbitan monooleate, 5-10 pts. petroleum sulfonate as a rust inhibitor, 3-5 pts. monoethanolamine, 64-82 pts. petroleum oil, 1-3 pts. lauryl alcohol, 1-3 pts. triazine derivative fungicide and 0.1-0.5 pts. silicone defoamer.

[12] CN107418693B acknowledges an aluminum alloy cutting fluid and a preparation method thereof, which are characterized by comprising the following raw materials in percentage by weight: 15-30% of naphthenic oil, 5-8% of boric acid ester containing sulfur and nitrogen, 3-5% of potassium borate, 2-4% of triethanolamine oleate, 4-8% of nonionic surfactant, 2-4% of anionic surfactant, 1-3% of corrosion inhibitor, 1-3% of antirust agent, 0.5-2% of stabilizer, 0.1-1.0% of defoaming agent, 0.1-0.5% of composite bactericide and the balance of deionized water.

[13] CN102746924B relates to aluminium hot-rolling oil, comprising 51-70wt% of mineral oil, 1-15wt% of non-ionic surfactant, 1-8wt% of phosphorous extreme pressure agent, 1-5wt% of antirust agent, 1-3wt% of mixed alcohol amine, 1-3wt% of oleic acid, 2-15wt% of polyol ester, and 0.1-0.5wt% of antifoaming agent, measured as the total weight of the hot-rolling oil.

[14] Lubricants widely used in the industry are expensive and maintenance of the lubricant is not adequate. Therefore, there is a need to develop lubricants for edge Trimming operations which overcome the aforesaid disadvantages.

SUMMARY OF THE INVENTION
[15] It is therefore an object of the invention to provide a lubricant for use in a metal forming process that overcomes the disadvantages of the prior art lubricants.

[16] An object of the invention is to provide a lubricant which gives sufficient lubrication, heat removal, and removal of fine and burrs at edge trimmer along with good product quality in terms of surface finish and productivity.

[17] Another object of the present invention is to develop a lubricant composition, which has adequate lubricity, a method of preparation and application thereof in Edge Trimming operations at Continuous Caster Machine.

[18] For achieving the above object, the invention provides lubricant composition comprises of:
• 80-99% (W/W) of at least one base oil;
• 1-10% (W/W) of at least one of a first additive;
• 0.5-5% (W/W) of at least one of a second additive; and
• 0.05-0.1% (W/W) of at least one antioxidant.

BRIEF DESCRIPTION OF THE INVENTION
[19] In describing and claiming the invention, the following terminology will be used in accordance with the definitions set forth below. Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. Although any methods and materials similar or equivalent to those described herein can be used in the practice or testing of the present invention, the preferred methods and materials are described herein. As used herein, each of the following terms has the meaning associated with it in this section. Specific and preferred values listed below for individual process parameters, substituents, and ranges are for illustration only; they do not exclude other defined values or other values falling within the preferred defined ranges.

[20] As used herein, the singular forms "a," "an," and "the" include plural reference unless the context clearly dictates otherwise.

[21] The terms “preferred” and “preferably” refer to embodiments of the invention that may afford certain benefits, under certain circumstances. However, other embodiments may also be preferred, under the same or other circumstances. Furthermore, the recitation of one or more preferred embodiments does not imply that other embodiments are not useful, and is not intended to exclude other embodiments from the scope of the invention

[22] As used herein, the terms “comprising” “including,” “having,” “containing,” “involving,” and the like are to be understood to be open-ended, i.e., to mean including but not limited to.

[23] The term “lubricant” as used herein refers to substance that helps to reduce friction between surfaces in mutual contact, which ultimately reduces the heat generated when the surfaces move. It may also have the function of transmitting forces, transporting foreign particles, or heating or cooling the surfaces.

[24] The term “edge trimming operation” as used herein refers to operation just after casting of aluminum sheet where uneven edges of casted sheet are trimmed by trimming tool (cutter) with the help of lubricant. Quality of lubricant decides the quality of edges. Quality of trimmed edges is very critical in further rolling process and quality of products. Quality of lubricant also decides the edge trimming tool life.

[25] The invention relates to a lubricant composition having adequate lubricity. The lubricant finds application in in edge trimming operations at continuous caster machine.

[26] Accordingly, the invention discloses a lubricant composition. The composition comprises of:
• 80-99% (Wt/Wt) of at least one base oil;
• 1-10% (Wt/Wt) of at least one of a first additive;
• 0.5-5% (Wt/Wt) of at least one of a second additive; and
• 0.05-0.1% (Wt/Wt) of at least one antioxidant.

[27] The aforesaid components are essential to provide a lubricant composition having superior benefits.

[28] The base oil is preferably a synthetic ester. A mixture of two esters or a single ester to get the of viscosity of final product in the range of 40-50 Cst at 40°C can be used. Esters are selected in such a way that final acid value of the product is< 2 mg/g of KOH and flash point is greater than 300°C. The concentration of base oil in the formulation is preferred to be in the range of 80-99%(W/W). The base oil provides appropriate viscosity for lubrication during edge trimming and reduces generation of fume during trimming.

[29] In an embodiment, esters are selected from a group consisting of, but not limited to trimethylolpropane (TMP) ester, trimellitate ester, penta ester and diesters.

[30] The first additive improves anti-wear and load bearing property. In an embodiment, these are amine selected from a group consisting of neutralized phosphoric acid esters of fatty alcohols, zinc dialkyldithiophosphates (ZDDP), amine-neutralized phosphoric acid ester (Nalube AW 6110). They are preferred in a range of 1-10% based on alloy composition and thickness of the sheet.

[31] The second additive is an anti-wear oil additive that protects metal parts from wear and tear. This additive is preferred in a range of 0.5-5% based on alloy composition and sheet thickness. This additive has polarized hydrocarbons which are attracted to the metal surfaces where they permeate into the metal structure. In an embodiment, the second additive is selected from a group consisting of ionic liquids such as trihexyltetradecyl phosphonium bis(2-ethylhexyl)phosphate, polytron MCT.

[32] Antioxidant improves the life of the lubricant formulation. In an embodiment, antioxidant is selected from a group consisting of, but not limited to butylated hydroxy toluene, butylated hydroxyl anisole, tert­ butylhydroquinone.

[33] The combination of these components in specific proportions results in a composition which has better lubricity, higher extreme property weld load and lower coefficient of friction.

[34] Subsequently, the aluminium roll is subjected to a metallurgical process where a thin layer of polished, harder metal is formed which increases the wear resistance of the metal parts and increases durability by at least a hundred times more.

[35] In an embodiment, the invention also provides a method for obtaining the lubricant composition, comprising the steps of:
(a) heating base oil at a temperature in the range of 50°C-70°C;
(b) adding a first additive to heated base oil of step (a) under stirring conditions;
(c) adding a second additive to mixture of step (b); and
(d) adding an anti-oxidant to mixture of step (c).

[36] In an embodiment, the heating of step (a) is carried out for a duration in the range of 1 to 2 hours. In an embodiment, stirring of step (b) is carried out for a duration in the range 0.5 to 1 hour.

[37] In an embodiment, step (c) and (d) is carried out at an elevated temperature in the range of 50°C-70°C.

[38] Beneficial effect of the lubricant composition of the present invention in aluminium rolling process is good cooling, rust prevention of aluminium rolls and increase the service life of aluminium rolls.

[39] Lubricant was poured into the application tank of Edge Trimmer. Lubricant was then applied with mist applicator on the blade of Edge Trimmers where trimmer blade makes contact with aluminum sheet.

WORKING EXAMPLES
PREPARATION OF LUBRICANT COMPOSITION
[40] 987.5 (gram/kg) of base oil Spak Ester 9260 was heated at a temperature in the range of 50°C-70°C for 1-2 hours. To the heated base oil, 10 (gram/kg) of a first additive Additin RC3760 was added to the heated base oil. The mixture was stirred for a duration of 45 Minutes.

[41] To the above mixture 2.5 (gram/kg) of a second additive Polytron MCT and 0.5 (gram/kg) of anti-oxidant Butylated hydroxytoluene (BHT). The temperature was maintained in the range of 50°C-70°C

[42] Subsequently the mixture stirred for a duration of 2 hours to obtain a lubricant with consistent viscosity.

[43] The properties of the lubricant oil are shown in table 1.

Test Parameters Test Method Observed Parameters
Flash Point (PMCC), 0C IS 1448 : (P 21) >250 0C
Kinematic Viscosity at 40 deg. C, mm2/s Auto ASTMD445 40-50 mm2/s
AW Test,
ASTM D4172 B Four Ball Tester Wear Scar Diameter 300-400 µm
EP Test - Pass load,
ASTM D2596 Four Ball Tester 160 Kg
EP Test - Weld load,
ASTM D2596 Four Ball Tester 200 Kg
Table 1

PREPARATION OF LUBRICANT COMPOSITION F14
[44] 987.5 (gram/kg) of base oil (Spak Ester 9260) was heated at a temperature in the range of 50°C-70°C for 1-2 hours. To the heated base oil, 10 (gram/kg) of a first additive (Additin RC3760) was added to the heated base oil. The mixture was stirred for a duration of 45 Minutes.

[45] To the above mixture 2.5 (gram/kg) of a second additive (Polytron MCT) and 0.5 (gram/kg) of anti-oxidant (Butylated hydroxytoluene (BHT)) The temperature was maintained in the range of 50°C-70°C

[46] Subsequently the mixture stirred for a duration of 2 hours to obtain a lubricant with consistent viscosity.

PREPARATION OF LUBRICANT COMPOSITION F19
[47] 950 (gram/kg) of base oil (Spak Ester 9260) was heated at a temperature in the range of 50°C-70°C for 1-2 hours. To the heated base oil, 45 (gram/kg) of a first additive (Additin RC3760) was added to the heated base oil. The mixture was stirred for a duration of 45 Minutes.

[48] To the above mixture 5 (gram/kg) of a second additive (Polytron MCT) and 0.5 (gram/kg) of anti-oxidant (Butylated hydroxytoluene (BHT)) The temperature was maintained in the range of 50°C-70°C

[49] Subsequently the mixture stirred for a duration of 2 hours to obtain a lubricant with consistent viscosity.

PREPARATION OF LUBRICANT COMPOSITION F20
[50] 900 (gram/kg) of base oil (Spak Ester 9260) was heated at a temperature in the range of 50°C-70°C for 1-2 hours. To the heated base oil, 95 (gram/kg) of a first additive (Additin RC3760) was added to the heated base oil. The mixture was stirred for a duration of 45 Minutes.

[51] To the above mixture 5 (gram/kg) of a second additive (Polytron MCT) and 0.5 (gram/kg) of anti-oxidant (Butylated hydroxytoluene (BHT)) The temperature was maintained in the range of 50°C-70°C

[52] Subsequently the mixture stirred for a duration of 2 hours to obtain a lubricant with consistent viscosity.

PREPARATION OF LUBRICANT COMPOSITION F21
[53] 980 (gram/kg) of base oil (Spak Ester 9260) was heated at a temperature in the range of 50°C-70°C for 1-2 hours. To the heated base oil, 10 (gram/kg) of a first additive (Additin RC3760) was added to the heated base oil. The mixture was stirred for a duration of 45 Minutes.

[54] To the above mixture 10 (gram/kg) of a second additive (Polytron MCT) and 0.5 (gram/kg) of anti-oxidant (Butylated hydroxytoluene (BHT)) The temperature was maintained in the range of 50°C-70°C

[55] Subsequently the mixture stirred for a duration of 2 hours to obtain a lubricant with consistent viscosity.

PREPARATION OF LUBRICANT COMPOSITION F22
[56] 965 (gram/kg) of base oil [Please provide the exact base oil used] [Spak Ester 9260] was heated at a temperature in the range of 50°C-70°C for 1-2 hours. To the heated base oil, 10 (gram/kg) of a first additive (Additin RC3760) was added to the heated base oil. The mixture was stirred for a duration of 45 Minutes.

[57] To the above mixture 25 (gram/kg) of a second additive (Polytron MCT) and 0.5 (gram/kg) of anti-oxidant (Butylated hydroxytoluene (BHT)) The temperature was maintained in the range of 50°C-70°C

[58] Subsequently the mixture stirred for a duration of 2 hours to obtain a lubricant with consistent viscosity.

[59] The properties of the lubricant compositions F14, F19, F20, 21 & 22 are shows in Table 2.

Properties F14 F-19 F-20 F-21 F-22
Viscosity at 40? 48.9 53.4 56.8 48.6 48.9
Flash Point COC, ? >280 >280 >280 >280 >280
Wear Scar Diameter in micron 376.77 387.5 384.2 349.5 320.5
EP Pass Load (kg) 126 126 126 126 126
EP Weld Load (kg) 160 160 160 160 160
Hot plate fumes (1 ml in aluminium cup) Low/Nil Low Low Low/Nil Low/Nil
Table 1
[60] All formulations i.e F-14, 19, F20, 21 & 22 gives good results in terms of low fume generations. Secondly lubrication properties in terms of wear scar diameter & EP pass load & weld are similar

EDGE TRIMMING OPERATION
[61] The formulation F-14 was tested for edge trimming operations. The edge trimming parameters are provided below in table 2.

Sr. No Parameter Details
1 Alloy AA3XXX
2 Temperature 757 0C/813 .3 0C
3 Metal temperature at Casting 710 0C
4 Casting Speed 0.83-0.90 MPM
5 Inlet water temperature 31 0C
6 Out let water temperature 33 0C
7 Inlet water pressure 2.6 Bar
Table 2
[62] It was observed that the surface finish of trimmed edge was smooth without scratch marks and vertical line marks & burrs. Stains on the aluminium sheets were reduced and the fume generation was reduced drastically.

[63] The foregoing description of the invention has been set merely to illustrate the invention and is not intended to be limiting. Since modifications of the disclosed embodiments incorporating the spirit and substance of the invention may occur to a person skilled in the art, the invention should be construed to include everything within the scope of the disclosure.

,CLAIMS:We Claim:

1) A lubricant composition comprising;
a) 80-99% (W/W) of at least one base oil;
b) 1-10% (W/W) of at least one of a first additive;
c) 0.5-5% (W/W) of at least one of a second additive; and
d) 0.05-0.1% (W/W) of at least one antioxidant.

2) The lubricant as claimed in claim 1, wherein said base oil comprises of one or more esters selected from a group consisting of, trimethylolpropane (TMP) ester, trimellitate ester, penta ester or diesters.

3) The lubricant as claimed in claim 1, wherein said first additive is selected from a group consisting of amine neutralized phosphoric acid esters of fatty alcohols, zinc dialkyldithiophosphates (ZDDP), amine-neutralized phosphoric acid ester.

4) The lubricant as claimed in claim 1, wherein said second additive is selected from a group consisting of ionic liquids such as trihexyltetradecyl phosphonium bis(2-ethylhexyl)phosphate or polytron MCT.

5) The lubricant as claimed in claim 1, wherein said antioxidant is selected from a group consisting of butylated hydroxy toluene, butylated hydroxyl anisole, tert­ butylhydroquinone.

6) The lubricant as claimed in claim 1, wherein kinematic viscosity of lubricant is in the range of 45-58 mm2/s.

7) A method for obtaining the lubricant composition, comprising the steps of:
(a) heating base oil at a temperature in the range of 50°C-70°C;
(b) adding a first additive to heated base oil of step (a) under stirring conditions;
(c) adding a second additive to mixture of step (b); and
(d) adding an anti-oxidant to mixture of step (c).

8) The method as claimed in claim 1, wherein the heating of step (a) is carried out for a duration in the range of 1 to 2 hours.

9) The method as claimed in claim 1, stirring of step (b) is carried out for a duration in the range 0.5 to 1 hour.

10) The method as claimed in claim 1, wherein step (c) and (d) is carried out at an elevated temperature in the range of 50°C-70°C.

Dated this 18 May 2021
M. Kisoth
IN/PA-2259
Agent for the Applicant