Title of Invention | A METHOD FOR DETERMINING ALUMINIUM CONTENT IN ALUMINIUM PAINTS |
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Abstract | The invention discloses a method for determining aluminium content in aluminium paints method for determining aluminium content in aluminium paints. The method comprising the steps of heating a paint sample on a hot plate for removal of the organic contents; adding gradually 10% NaOH solution in hot condition until reaction with the sample ceases; cooling the material to room temperature and adding cold H2O2 solution for complete oxidation; adding concentrated hydrochloric acid and boiling to bring the entire residual mass into a solution; filtering the mass by filter paper and collecting the filtrate in a volumetric flask; washing the residue with hot water to make it acid free; igniting the residue with the filter paper at a temperature of 1000°C; fusing the ignited material with potassium pyro sulphate, dissolving the fused mass in dilute hydrochloric acid and transferring the mother solution to a volumetric flask; adding 2 gms of sodium carbonate, 1 gm of borax, 20 ml concentrated HNO3, 20 ml of solution and 5ml of 2000 ppm copper solution in a 250 ml volumetric flask; making up the volume upto the mark while shaking well ; and calibrating a program on an ICP spectrometer for measuring the aluminium content. |
Full Text | FIELD OF THE INVENTION The present invention relates to a method for determining aluminium content in aluminium paints. BACKGROUND OF THE INVENTION Aluminium paints are used extensively as coating material on structural for prevention of corrosion. Aluminium content in the paint is very important for the quality of the paint. Deterioration in the life of painted surfaces can be correlated with the aluminium content in paints. There is no existing method for chemical analysis of aluminium content in paints. A need therefore, exists for the estimation of aluminium content in paints. SUMMARY OF THE INVENTION The main object of the present invention therefore is to provide a method for estimating the aluminium content in paints used for providing a protective coating on structural surfaces against corrosion. The process for such testing of aluminium content in paints will broadly involve steps like collection of samples, removal of any organic portion of the paint from the sample, bringing the residue into an aqueous solution, measuring the aluminium content of the solution by inductively coupled plasma technique and checking for repeatability and reproducibility of the method. Thus, the present invention provides a method for determining aluminium content in aluminium paints comprising the steps of a) heating a paint sample on a hot plate for removal of the organic contents; b) adding gradually 10% NaOH solution in hot condition until reaction with the sample ceases; c) cooling the material to room temperature and adding cold H2O2 solution for complete oxidation; d) adding concentrated hydrochloric acid and boiling to bring the entire residual mass into a solution; e) filtering the mass by filter paper and collecting the filtrate in a volumetric flask; f) washing the residue with hot water to make it acid free; g) igniting the residue with the filter paper at a temperature of 1000°C; h) fusing the ignited material with potassium pyro sulphate, dissolving the fused mass in dilute hydrochloric acid and transferring the mother solution to a volumetric flask; i) adding 2 gms of sodium carbonate, 1 gm of borax, 20 ml concentrated HNO3, 20 ml of solution of step (h) and 5 ml of 2000 ppm copper solution in a 250 ml volumetric flask; j) making up the volume upto the mark while shaking well; and k) calibrating a program on an ICP spectrometer and measuring the aluminium content. DETAILED DESCRIPTION OF THE INVENTION For estimation of aluminium in paints, a sample of the paint of say 0.5 gms can be taken in a beaker. The beaker can be made to a material like for example, Teflon and heated on a hot plate so that the organic constituents of the paint like base oil and thinner can be removed. The material can be heated upto a temperature of 200°C for about two hours. 10% sodium hydroxide NaOH (aqueous solution wt./vol) is then added slowly to the material in heated condition till the reaction ceases. The Teflon beaker can then be removed from the hot plate and allowed to be brought to room temperature. Cooled hydrogen peroxide H2O2 solution is then added by drops for complete oxidation of the material. 10-15 ml of concentrated hydrochloric acid HC1 is then added and boiled a little to bring the entire residual mass into a solution. The solution is then filtered, which can be done by using double Whatman 41 filter paper. The filtrate can be collected in a volumetric flask of say 100 ml capacity. The residue is then washed with hot water to make it acid free. The washed residue is then taken into a platinum crucible along with the filter paper,dried and ignited at a temperature of 1000° C. This can be done in a muffle furnace. The ignited material is then fused with a minimum quantity of potassium pyro sulphate. The fused mass is dissolved in a minimum quantity of dilute hydrochloric acid and transferred to the mother solution in the volumetric flask. The volume is made up to the mark with distilled water. 2 gms of sodium carbonate, 1 gm of borax, 20 ml of concentrated nitric acid, 20 ml of solution from the previous step and 500 ml of 2000 ppm copper solution are taken in a 250 volumetric flask. The volume is made up to the mark and shaken well. A calibration program of an ICP spectrometer is then made using synthetic aqueous standards covering a range of concentrates of aluminium upto 50%. The ICP spectrometer used for the purpose can be of Spectro Analytical, Germany. The ICP's spectrometer is used for measuring the aluminium content. Repeatability tests can be carried out. From a particular sample,the following values were obtained 6.74, 6.51, 6.67, 6.81, 6.58, 6.65, 6.52, 6.75 and 6.69 % which provide an average value of 6.65X with a standard deviation of 0.10%. WE CLAIM 1. A method for determining aluminium content in aluminium paints in a sample comprising the steps of: (a) a paint sample of 5-10 gm is heated at 200°C for three hours on a hot plate for removal of organic components; (b) adding gradually 20-30 ml of 10% NaOH aqueous solution in wt/vol in hot condition until reaction with the sample ceases; (c) cooling the material to room temperature and adding cold H2O2 solution 3-4 ml for complete oxidation; (d) adding 10-15 ml of concentrated hydrochloric acid and boiling to bring the entire residual mass into a solution; (e) filtering the mass by double Whatsman 41 filter paper and collecting the filtrate in a volumetric flask, of 100 ml capacity; (f) washing the residue with hot water to make it acid free; (g) igniting the residue with the filter paper in a platinum crucible inside a muffle furnace at a temperature of 1000-1050°C; (h) fusing the ignited material with 2-4 gms potassium pyro sulphate dissolving the fused mass in 10-20 ml dilute hydrochloric acid and transferring the molten solution to a volumetric flask; (i) adding 2-4 gms of sodium carbonate, 1 -2 gm of borax, 20 ml concentrated Nitric acid to 20 ml of solution of step(h) and adding 500-600 ml of 2000 ppm copper solution in a 250 ml volumetric flask; (j) making up the volume up to the mark while shaking well and (k) calibrating a program on an ICP spectrometer for measuring the aluminium content using synthetic aqueous standards covering a range of concentrates of aluminium. characterised in that said sample in the form of solution is aspirated into argon plasma wherein the different constituents of the sample get excited to higher energy levels and while coming back to the ground state, they emit characteristic radiation and intensity of the characteristic radiation of the element of interest is measured using photo multipliers or CCD detectors and by referring to the calibration graph stored in the system, concentration of aluminium is known (Aluminium characteristic wave length monitored is 308.215 nra). 2. The method as claimed in claim 1, wherein different values can be obtained by repeating steps (a) to (k) for a given sample. 3. The method as claimed in claim 1, wherein ICP spectrometer used is of spectro analytical, Germany. The invention discloses a method for determining aluminium content in aluminium paints method for determining aluminium content in aluminium paints. The method comprising the steps of heating a paint sample on a hot plate for removal of the organic contents; adding gradually 10% NaOH solution in hot condition until reaction with the sample ceases; cooling the material to room temperature and adding cold H2O2 solution for complete oxidation; adding concentrated hydrochloric acid and boiling to bring the entire residual mass into a solution; filtering the mass by filter paper and collecting the filtrate in a volumetric flask; washing the residue with hot water to make it acid free; igniting the residue with the filter paper at a temperature of 1000°C; fusing the ignited material with potassium pyro sulphate, dissolving the fused mass in dilute hydrochloric acid and transferring the mother solution to a volumetric flask; adding 2 gms of sodium carbonate, 1 gm of borax, 20 ml concentrated HNO3, 20 ml of solution and 5ml of 2000 ppm copper solution in a 250 ml volumetric flask; making up the volume upto the mark while shaking well ; and calibrating a program on an ICP spectrometer for measuring the aluminium content. |
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00168-kol-2005 correspondence-1.1.pdf
00168-kol-2005 correspondence-1.2.pdf
00168-kol-2005 correspondence-1.3.pdf
00168-kol-2005 correspondence.pdf
00168-kol-2005 description(complete).pdf
00168-kol-2005 other document.pdf
168-KOL-2005-(12-12-2011)-FORM-27.pdf
168-kol-2005-granted-abstract.pdf
168-kol-2005-granted-claims.pdf
168-kol-2005-granted-correspondence.pdf
168-kol-2005-granted-description (complete).pdf
168-kol-2005-granted-examination report.pdf
168-kol-2005-granted-form 1.pdf
168-kol-2005-granted-form 13.pdf
168-kol-2005-granted-form 18.pdf
168-kol-2005-granted-form 2.pdf
168-kol-2005-granted-form 3.pdf
168-kol-2005-granted-form 5.pdf
168-kol-2005-granted-reply to examination report.pdf
168-kol-2005-granted-specification.pdf
Patent Number | 233875 | |||||||||||||||
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Indian Patent Application Number | 168/KOL/2005 | |||||||||||||||
PG Journal Number | 16/2009 | |||||||||||||||
Publication Date | 17-Apr-2009 | |||||||||||||||
Grant Date | 16-Apr-2009 | |||||||||||||||
Date of Filing | 15-Mar-2005 | |||||||||||||||
Name of Patentee | TATA STEEL LIMITED | |||||||||||||||
Applicant Address | RESEARCH AND DEVELOPMENT AND SCIENTIFIC SERVICES DIVISION, JAMSHEDPUR | |||||||||||||||
Inventors:
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PCT International Classification Number | G01N 21/04 | |||||||||||||||
PCT International Application Number | N/A | |||||||||||||||
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