Title of Invention

LUBRICANT COMPOSITION, METHOD FOR PREPARATION THEREOF AND APPLICATION THEREOF TO CUTTING BLADE USED IN PRECISION CUTTING MACHINES

Abstract

The present invention discloses a Lubricant composition comprising (a) 90 to 98 parts by mass of a refined petroleum fraction such as herein described, said petroleum fraction having kinematic viscosity in the range of 40 to 60 mm2/s at 40° C, and having paraffinic hydrocarbon content of more than 95% said paraffinic hydrocarbon having a carbon chain length of 12 to 40 carbon atoms (b) 2 to 10 parts by mass of a fatty acid being a single fatty acid, such as herein described, having a molecular weight in the range of about 200 to 300, and having a carbon chain length of 12 to 18 carbon atoms, and optionally about 0 01 to 0 05 parts by mass of phenolic compound, such as herein described.

Full Text

The present invention relates to a lubricant composition, and the method of its preparation. This invention also relates to a method for applying the lubricant to cutting blades used at precision cutting machines for high speed cutting of non-ferrous metal sheets such as, aluminium sheets. In high-speed precision cutting machines for cutting of non-ferrous metal sheets, during the cutting operation, the cutting blade picks up metal from the sheet edges and this metal which sticks generates edge burrs on the cut sheet edges which are unacceptable from the point of quality. Also, the cutting blade looses its sharpness and needs to be replaced often. Replacement and proper setting of blades in such high-speed precision cutting machines is a costly exercise and, consumes lot of skilled man-hours and involves closedown of machine for long period of time. Application of a suitable lubricant to the cutting blade would prevent this metal from sticking and would extend the life of the cutting blade, thus saving a lot of machine closedown time period, skilled labour man-hours and cost. Therefore, suitable lubrication is necessary for smooth cutting of metal sheets, to ensure that the cut edges are burr-free resulting in longer life of the cutting blade. In most cases, cutting of aluminium sheets is being carried out by dry-cutting techniques i.e., without any lubricant,for the reasons given below. As a result, the life of the cutting blade becomes very short and edge burrs start appearing after a relatively short period of cutting. -2- In some cases, a volatile solvent such as kerosene is used (by spray method) on cutting blades. Since, the solvent evaporates quickly, there is no risk of oil carryover. However, this brings in only a marginal improvement in the cut edge quality and extension of life of the cutting blade. None of the techniques of prior art produce the desired result, as required, for cutting of non-ferrous metal sheets such as, aluminium sheets, in high speed precision cutting machines. Also, providing lubrication at the cutting blade has been a problem because, in many cases, the cut surfaces of sheets have to be free from any oil/lubricant, due to the nature of their post-application. Degreasing (removal of oil/lubricant) of sheets after the cutting operation is not viable from cost, quality and practical points of view. Therefore, lubrication of the cutting blade has to be carried out in such a way that no oil/lubricant drips on sheet surface including edges. Also, there should not be any visible carry-over of oil/lubricant from blade to sheet. Therefore, the desirable aspects of the lubrication are a) application of lubricant should be such that very small quantity of lubricant is applied to the cutting blade edge; b) cut sheet edges should be burr-free and there should be no visible carry-over of lubricant to the sheet; c) cutting blade should be lubricated before each cutting operation; -3- d) lubricant should have good lubricity and good anti-wear properties, e) lubricant should be eco-friendly, no occupational health and safety hazards must be involved; and, J f) components of the lubricant should not have tendency to react with freshly generated metal surfaces at the cut edges of sheet; also, they should not cause any kind of stains on the metal. The principal objective of the present invention, therefore, is to develop a lubricant composition including the preparation thereof, and a method of application, suitable for lubrication of the cutting blades of high-speed precision cutting machines for cutting of non-ferrous metal sheets such as, aluminium sheets. This invention relates to new compositions of matter suitable for use as a lubricant, method for its preparation and a novel method for applying the lubricant composition for lubrication of cutting blade for cutting of non-ferrous metal (such as, aluminium and its alloys) sheets. Accordingly, the present invention provides a lubricant composition comprising: (A) 90 to 98 parts by mass of a refined petroleum fraction such as herein described, said petroleum fraction having kinematic viscosity in the range of 40 to 60 mm2/s at 40°C, and having paraffinic hydrocarbon content of more than 95%, said paraffinic hydrocarbon having a carbon chain length of 12 to 40 carbon atoms, -4- (B) 2 to 10 parts by mass of a fatty acid being a single fatty acid such as herein described, having a molecular weight in the range of about 200 to 300, and having a carbon chain length of 12 to 18 carbon atoms, and (C) optionally about 0 01 to 0.05 parts by mass of a phenolic compound, such as herein described. The present invention also provides a method for the preparation of said lubricant composition, said method comprising the steps of (a) Warming 90 to 98 parts by mass of refined petroleum fraction such as herein described, having a kinematic viscosity in the range of 40 to 60 mm2/s at 40°C, having paraffinic hydrocarbon content of more than 95%, to a temperature of about 45 to 55°C, said paraffinic hydrocarbon having a carbon chain length of 12 to 40 carbon atoms, (b) adding 2 to 10 parts by mass of a fatty acid being a single fatty acid, such as herein described, having a molecular weight in the range of about 200 to 300 and having a carbon chain length of 12 to 18 carbon atoms to the warmed petroleum fraction of step (a) and stirring while maintaining the temperature at about 45 to 55°C to form a homogeneous mixture; and (c) cooling said homogeneous mixture to room temperature; and (d) optionally, before the step (c) of cooling, adding about 0.01 to 0.05 parts by mass of an phenolic compound such as herein described to said homogeneous mixture while maintaining the temperature at about 45 to 55 °C and stirring the mixture. -5- The present invention further provides a method for applying the lubricant composition to a cutting blade used at precision cutting machines for cutting of non-ferrous metals, comprising: mounting an absorbing pad, which is stiff and elastic enough to retain its shape during continuous contact with said cutting blade, on the cutting table of the cutting machine so that only one edge of pad along the length of the pad comes in contact with the cutting edge of the cutting blade so as to just brush the cutting edge of the cutting blade; and applying said lubricant along the length of said pad on the opposite edge of said pad, so that the lubricant slowly and gradually spreads throughout the pad, whereby the said one edge of the pad which comes into contact with the cutting blade becomes wet with the lubricant and lubricates the cutting blade by brushing. Paraffinic hydrocarbon liquids and refined petroleum oils, in the kinematic viscosity range of 40 to 60 mm2/s at 40°C, are preferred petroleum fractions forming component A. Preferred examples of component B are: Hexadecanoic acid, octadecanoic acid, Dodecanoic acid, Tetradecanoic acid etc Component B enhances lubricity and, provides anti-wear properties to the composition - 6 - Organic phenolic compound forming component C may be 2,6 di-tert butyl p-cresol, 4 methyl butyl phenol, butylated hydroxy anisole, etc. Component C imparts anti-oxidation property to the lubricant composition. It is preferable to maintain the temperature at about 45-55°C during preparation of the composition since, at temperatures above 60°C, the component B may undergo oxidation, which is undesirable. The most preferred temperature is about 50°C. It may be noted that the first two components viz., component A and component B are absolutely essential for formulation of the lubricant composition. The third component i.e., component C is required only for extension of life of the lubricant composition, and hence is an optional component. It may be mentioned that none of the above components can be used individually as lubricant for the lubrication of cutting blades to get the desired results. Component A has lubricity, but it is not adequate. Component B is essential for enhancing the lubricity and to provide good anti-wear properties. Component B alone can not be used for the said application because of its lack of flowability. Therefore, it is clear that none of the components mentioned above can be used individually as lubricant for lubrication of cutting blades. However, the components A and B, and optionally component C together can be used to formulate lubricant compositions for use as lubricant for cutting blades. It may be again highlighted that the -7- components A and B are absolutely essential for the lubricant composition to perform. Component C is only an anti-oxidant. All the components, when formulated together, do not have any chemical reaction between them. But, in use, they impart a synergistic effect for the composition to perform as good lubricant for the lubrication of cutting blades. As mentioned earlier, if the components of the lubricant have a tendency to attack highly reactive freshly generated cut edges of metal sheets, imperfections would develop. Therefore, selection of components for the present invention has been done with due consideration, to eliminate the said ill factor. Also, all the components used belong to Indian Pharmacopia or equivalent grade, so that the formulation is ecofriendly. No health and safety hazards are involved in the formulation. As previously stated, the lubricant composition of this invention contains 90 to 98 parts by mass of component A, at least 2 parts by mass of component B and, optionally 0.01 to 0.05 parts by mass of component C. Examples of typical formulations are given below: Composition 1 Composition 2 Composition 3 Component (A) : 97.00 parts 97.98 parts 95.00 parts (Heavy liquid (Heavy liquid (Heavy liquid Paraffin) Paraffin) Paraffin) Component (B) : 2.95 parts 2.00 parts 4.95 parts (Hexadecanoic (Octadecanoic (Dodecanoic Acid) Acid) Acid) Component (C) : 0.05 parts 0.02 parts 0.05 parts (2,6 di-tert. (2,6 di-tert. (Butylated butyl p-cresol) butyl p-cresol) Hydroxy Anisole) -8- Various other formulations with the above components can be made to suit the needs of specific cutting application. PREPARATION OF THE LUBRICANT COMPOSITION One method of preparing the composition will hereinafter be described. Required quantity of component A is taken in a glass vessel and warmed to about 50°C. Then, component B is added in desired proportions with constant stirring, while maintaining the temperature at about 50°C. There is no chemical reaction during mixing. When the mass becomes homogeneous, component C is added in required proportion if required. The entire mass is made uniform through agitation and, then cooled to room temperature. APPLICATION OF THE LUBRICANT Cutting blades are to be lubricated just before each cutting operation. Lubricant has to be restricted to very small quantity so that, carry-over of lubricant from blade to sheet edge during cutting is negligible and, at the same time, ensure that the blade edge is lubricated continuously. An absorbing pad, which is stiff and elastic enough to retain its shape from any deformation due to its continuous contact with the blade during cutting operation is used for applying the lubricant. The pad should be capable of absorbing the lubricant. Also it should not deteriorate or undergo permanent deformation after absorbing the lubricant. This means that the pad should not lose its strength and also that it should not undergo any expansion. The most suitable materials for the pad are woollen felt material and the like. Length of the pad should be slightly more than that of the -9- cutting blade Pads with dimensions: thickness ranging from 0.5 cm to 2 cm and, and width ranging from 5 cm to 20 cm may be used as suitable. The pad is to be fitted on the cutting table in such a way that, every time the blade moves in for cutting, the pad just brushes the blade edge. That means, only one edge of the pad along the length comes in contact with the blade edge. It has to be ensured that this edge of the pad is cut accurately along a straight line before fitting. The lubricant is to be applied along the length of the pad only on the other side (i.e., the side other than the one which comes in contact with cutting blade), so that it will gradually and slowly flow to the side which comes into contact with the cutting blade. The lubricant is to be applied periodically in small quantities just enough to maintain the pad wet at all times. The lubricant can be applied to the other side by means of a universal oil can. With this arrangement, before every cutting operation, cutting blade just brushes the pad edge and gets lubricated. This method of application ensures that: (a) Lubricant is effectively applied to the cutting blade in very small quantities and it provides adequate lubrication and anti-wear property; (b) The cutting blade is lubricated before each cutting operation; and (c) There is no visible carry-over of lubricant on to the sheet. EVALUATION OF THE LUBRICANT FORMULATION The lubricant formulation, given in the above example of -10- Composition 1 has been evaluated as given below: 1. Physicochemical properties Sr.No. Parameter Method Ref. Test Data 1. Appearance Clear, free from suspended matter and undissolved water 2. Colour, ASTM ASTM D 1500 3. Specific gravity at 26°C. ASTM D 1298 0.850 4. Kinematic Viscosity at 40°C, mm2/s ASTM D 445 52 5. Viscosity Index ASTM D 446 96 6. Water content, % by volume ASTM D 95 Nil 7. Sediment, % by volume ASTM D 96 Nil 2. Performance in Machine The lubricant composition has been used by the applicants at a cutting machine (make-Esmech Rolling Machinery Pvt. Ltd., Mumbai) used for cutting of Aluminium sheets (thickness range 0.2 mm to 1 mm), at a speed of 50 cuts per minute. The performance of the lubricant was found to be excellent. The blade life increased from an average of 1-2 lakh cuts per blade to more than 15 lakh cuts per blade. There were no complaints of burr or oil carry-over. Periodicity of lubrication of the pad was about once in 25,000 to 50,000 cuts. It is clear that the lubricant composition, prepared as -11- per the formulation and process thereof and, applied in a manner stated in previous paragraphs, (I) has performed very well in actual cutting operation i.e., cut edges are free from burr and there is no visible carry-over of lubricant on to the sheet; (II) has very good lubricity and anti-wear properties; and (III)involves no occupational health and safety hazards. Advantages of the lubricant composition of the present invention are: (a) The lubricant has good lubricity and anti-wear properties to ensure smooth cutting of metal sheets. (b) The cut edges are burr-free. (c) Life of cutting blade is increased by about 10 times. (d) Lubricant does not react with highly reactive freshly generated metal surface at the cut edges; (e) Lubricant does not cause any kind of stains on the metal; and (f) Lubricant does not have any occupational health and safety hazards; even skin contact is harmless; The lubricant formulation of the present invention is not a mere admixture of components A, B and C. The formulation has a synergistic effect of providing good lubrication and good anti-wear properties when applied in the manner described in previous paragraphs for lubrication of cutting blades of high speed precision cutting machines. -12- WE CLAIM 1 Lubricant composition comprising (a) 90 to 98 parts by mass of a refined petroleum fraction such as herein described, said petroleum fraction having kinematic viscosity in the range of 40 to 60 mm2 /s at 40° C, and having paraffinic hydrocarbon content of more than 95% said paraffinic hydrocarbon having a carbon chain length of 12 to 40 carbon atoms (b) 2 to 10 parts by mass of a fatty acid being a single fatty acid, such as herein described, having a molecular weight in the range of about 200 to 300 and having a carbon chain length of 12 to 18 carbon atoms, and (c) optionally about 0 01 to 0 05 parts by mass of phenolic compound, such as herein described 2 Lubricant composition as claimed in claim 1, wherein said refined petroleum fraction is selected from paraffinic hydrocarbon liquids and refined petroleum oils having kinematic viscosity in the range of 40 to 60 mm2/s at 40° C 3 Lubricant composition as claimed in claim 2, wherein said fatty acid is selected from dodecanoic acid, tetradecanoic acid, hexadecanoic acid, octadecanoic acid. 4 Lubricant composition as claimed in any of claims 1 to 3, wherein said inhibited phenolic compound is selected from 2,6 di-tert p-cresol, 4 methyl butyl phenol, butylated hydroxy anisole. 5 Method for preparation of lubricant composition as claimed in claim 1. said method comprising the steps of (a) warming 90 to 98 parts by mass of a refined petroleum fraction such as herein described, having a kinematic viscosity in the range of 40 to 60 mm2/s at 40° C. and having paraffinic hydrocarbon content of more than 95%, to a -13- temperature of about 45 to 55°C, said paraffinic hydrocarbon having a carbon chain length of 12 to 40 carbon atoms, (b) adding 2 to 10 parts by mass of a fatty acid being a single fatty acid, such as herein described, having a molecular weight in the range of about 200 to 300 and having a carbon chain length of 12 to 18 carbon atoms to the warmed petroleum fraction of step (a) and stirring while maintaining the temperature at about 45 to 55°C to form a homogeneous mixture, and (c) cooling said homogeneous mixture to room temperature, and (d) optionally, before said step (c) of cooling, adding about 0 01 to 0 05 parts by. mass of an inhibited phenolic compound such as herein described to said homogeneous mixture while maintaining the temperature at about 45 to 55°C and stirring the mixture 6 Method as claimed in claim 5 wherein said refined petroleum fraction is selected from paraffinic hydrocarbon liquids and refined petroleum oils having kinematic viscosity in the range of 40 to 60 mm2/s at 40° C 7 Method as claimed in claim 6 wherein said fatty acid is selected from dodecanoic acid, tetradecanoic acid, hexadecanoic acid, octadecanoic acid- 8 Method as claimed in any of claims 5 to 7, wherein said inhibited phenolic compound is selected from 2,6 di-tert butyl p-cresol, 4 methyl butylphenol, butylated hydroxy anisole - 9 Method as claimed in any of claims 5 to 8, wherein the temperature is maintained at about 45-55°C, and preferably at about 50°C 10 Method for applying the lubricant composition as claimed in any of claims 1 to 6 to a cutting blade used in precision cutting machines for cutting of non-ferrous metals, comprising - 14- mounting an absorbing pad, which is stiff and elastic enough to retain its shape during continuous contact with said cutting blade, on the cutting table of the cutting machine so that only one edge of pad along the length of the pad comes in contact with the cutting edge of the cutting blade so as to just brush the cutting edge of the cutting blade, and applying said lubricant along the length of said pad on the opposite edge of said pad, so that the lubricant slowly and gradually spreads throughout the pad, whereby the said one edge of the pad which comes into contact with the cutting blade becomes wet with the lubricant and lubricates the cutting blade by brushing 11 Method as claimed in claim 10, wherein said pad has a thickness of 0 5 to 2 cm and a width of 5 to 20 cm 12. Method as claimed in claim 10 or 11, wherein said pad is made of woolen felt material - 13 Lubricant composition substantially as herein described, particularly with reference to the foregoing examples 14 Method for the preparation of a lubricant composition substantially as herein described (I.S. BHATTACHARYA) OF D P AHUJA & CO. APPLICANT'S AGENT Dated this 10th day of December, 1998 -15- The present invention discloses a Lubricant composition comprising (a) 90 to 98 parts by mass of a refined petroleum fraction such as herein described, said petroleum fraction having kinematic viscosity in the range of 40 to 60 mm2/s at 40° C, and having paraffinic hydrocarbon content of more than 95% said paraffinic hydrocarbon having a carbon chain length of 12 to 40 carbon atoms (b) 2 to 10 parts by mass of a fatty acid being a single fatty acid, such as herein described, having a molecular weight in the range of about 200 to 300, and having a carbon chain length of 12 to 18 carbon atoms, and optionally about 0 01 to 0 05 parts by mass of phenolic compound, such as herein described.

Documents:

02157-cal-1998-abstract.pdf

02157-cal-1998-claims.pdf

02157-cal-1998-correspondence.pdf

02157-cal-1998-description(complete).pdf

02157-cal-1998-form-1.pdf

02157-cal-1998-form-2.pdf

02157-cal-1998-form-3.pdf

02157-cal-1998-gpa.pdf

2157-CAL-1998-FORM 15.pdf

2157-CAL-1998-FORM-27.pdf

2157-cal-1998-granted-abstract.pdf

2157-cal-1998-granted-claims.pdf

2157-cal-1998-granted-correspondence.pdf

2157-cal-1998-granted-description (complete).pdf

2157-cal-1998-granted-examination report.pdf

2157-cal-1998-granted-form 1.pdf

2157-cal-1998-granted-form 2.pdf

2157-cal-1998-granted-form 3.pdf

2157-cal-1998-granted-gpa.pdf

2157-cal-1998-granted-letter patent.pdf

2157-cal-1998-granted-reply to examination report.pdf

2157-cal-1998-granted-specification.pdf