1、Designation: D3969 01 (Reapproved 2012)Standard Test Method forZirconium in Paint Driers by EDTA Method1This standard is issued under the fixed designation D3969; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last rev
2、ision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.1. Scope1.1 This test method covers the titrimetric determination ofzirconium in zirconium driers used in the coatings industry andutilize
3、s the disodium salt of ethylenediaminetetraacetic aciddihydrate (EDTA).1.2 This test method is limited to the determination of thezirconium content of a liquid zirconium drier that does notcontain other drier elements. The test method is not applicableto drier blends and does not differentiate hafni
4、um fromzirconium.1.3 All cations that can be titrated with EDTAin acid mediainterfere and must not be present in the sample.1.4 This test method has been tested for concentrations of 6and 12 % zirconium, but there is no reason to believe that it isnot suitable for higher or lower zirconium concentra
5、tions,provided specimen size is adjusted proportionately.1.5 The values stated in SI units are to be regarded asstandard. No other units of measurement are included in thisstandard.1.6 This standard does not purport to address all of thesafety concerns, if any, associated with its use. It is theresp
6、onsibility of the user of this standard to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:2D600 Specification for Liquid Paint DriersD1193 Specification for Reagent WaterE180 Practic
7、e for Determining the Precision of ASTMMethods for Analysis and Testing of Industrial and Spe-cialty Chemicals (Withdrawn 2009)3E300 Practice for Sampling Industrial Chemicals3. Summary of Test Method3.1 The zirconium drier is digested with concentrated sul-furic acid and 30 % hydrogen peroxide to d
8、estroy all organicmatter. The diluted solution is boiled with an excess of EDTA,the pH adjusted, and the excess titrated with bismuth nitrateusing xylenol orange as the indicator.4. Significance and Use4.1 The amount of zirconium drier used in oxidizing-typecoatings significantly affects their dryin
9、g properties. This testmethod may be used to confirm the stated content of a pureliquid zirconium drier manufactured for use by the coatingsindustry.5. Apparatus5.1 Centrifuge, capable of developing 1000 to 2000 g.6. Reagents6.1 Purity of ReagentsReagent grade chemicals shall beused in all tests. Un
10、less otherwise indicated, it is intended thatall reagents shall conform to the specifications of the Commit-tee on Analytical Reagents of the American Chemical Society,where such specifications are available.4Other grades may beused, provided it is first ascertained that the reagent is ofsufficientl
11、y high purity to permit its use without lessening theaccuracy of the determination.6.2 Purity of WaterUnless otherwise indicated, referencesto water shall be understood to mean reagent water conformingto Type II of Specification D1193.6.3 Ammonium Hydroxide (sp gr 0.90)Concentrated, am-monium hydrox
12、ide (NH4OH).1This test method is under the jurisdiction of ASTM Committee D01 on Paintand Related Coatings, Materials, and Applications and is the direct responsibility ofSubcommittee D01.21 on Chemical Analysis of Paints and Paint Materials.Current edition approved June 1, 2012. Published July 2012
13、. Originally approvedin 1980. Last previous edition approved in 2006 as D3969 01 (2006). DOI:10.1520/D3969-01R12.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the
14、 standards Document Summary page onthe ASTM website.3The last approved version of this historical standard is referenced onwww.astm.org.4Reagent Chemicals, American Chemical Society Specifications, AmericanChemical Society, Washington, DC. For suggestions on the testing of reagents notlisted by the
15、American Chemical Society, see Analar Standards for LaboratoryChemicals, BDH Ltd., Poole, Dorset, U.K., and the United States Pharmacopeiaand National Formulary, U.S. Pharmacopeial Convention, Inc. (USPC), Rockville,MD.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohock
16、en, PA 19428-2959. United States16.4 Bismuth Nitrate, Standard Solution (0.05 M)Dissolve24.25 g of bismuth nitrate (Bi(NO3)5H2O) in 20 to 30 mL ofconcentrated nitric acid (use a magnetic stirrer if possible).After solution is complete, dilute to 1 L with water.NOTE 1Add the water very slowly to the
17、acid solution, while coolingthe flask in an ice bath to prevent splattering.6.5 EDTA, Standard Solution(0.05 M)Dissolve 18.61 g ofEDTA in 300 to 500 mL of water and dilute to 1 L. Store in apolyethylene or borosilicate glass bottle.6.6 Eriochrome Black-T IndicatorTriturate 0.100 g ofpowdered Eriochr
18、ome Black-T with 100 g of sodium chloride(NaCl), and store the mixture in a tightly stoppered bottle. Thismixture remains stable for several years.6.7 Formic Acid (sp gr 1.22, 90 %) HCOOH.6.8 Hydrochloric Acid (sp gr 1.19)Concentrated hydro-chloric acid (HCl).6.9 Hydrogen Peroxide (30 %).6.10 Isopro
19、pyl Alcohol (99.5 %).6.11 Nitric Acid (sp gr 1.42)Concentrated nitric acid(HNO3).6.12 Phenolphthalein Indicator (1.0 %)Dissolve 1.0 g ofphenolphthalein indicator in 100 mL of methanol, ethanol, orisopropanol.6.13 Sodium Sulfite (Na2SO3).6.14 Sulfuric Acid (sp gr 1.84)Concentrated sulfuric acid(H2SO4
20、).6.15 Xylenol Orange (0.2 %)Dissolve 0.2 g in 100 mL ofwater. Prepare fresh each day used.6.16 Zinc Chloride, Standard Solution (0.100 M)Dissolve6.538 g of zinc ribbon (Note 2) in concentrated HCl, keepingthe excess of acid as small as possible. After the zinc hasdissolved, cool to room temperature
21、 and dilute to 1 L in avolumetric flask.NOTE 2Store the zinc ribbon in a tightly closed container to preventthe surface of the zinc from oxidizing.7. Sampling7.1 Take a small sample of liquid drier from bulk using theprocedure in Practice E300 appropriate for the size of thecontainer: section on Bot
22、tle Sampling for tanks and tank cars,or section on Tube Sampling for drums and cans.NOTE 3Liquid driers are normally homogeneous so that only simplephysical tests, such as specific gravity or solids content, on top and bottomsamples from tanks, are required to confirm that separation has notoccurred
23、. Agitate drums in accordance with section on Tube Sampling inPractice E300.7.2 Examine the sample of drier for sediment or suspendedmatter which, if present, is evidence of noncompliance withSpecification D600.7.3 If the sample is homogeneous keep it in a stopperedvessel to prevent solvent evaporat
24、ion prior to analysis.8. Standardization8.1 Zinc Chloride, Standard Solution (0.100 M)Calculatethe molarity, M1, of the zinc chloride (ZnCl2) solution asfollows:M15S165.37(1)where:S1= zinc used, g, and65.37 = zinc to producea1Msolution, g/L.8.2 EDTA, Standard Solution (0.05 M)Pipet 20 or 25-mLportio
25、ns (use calibrated pipets) of the standard ZnCl2solutioninto a 250-mL Erlenmeyer flask. Add concentrated NH4OHdropwise until the precipitate which forms redissolves. Add 3mL more of NH4OH. Add 0.20 to 0.25 g Eriochrome Black-Tindicator mixture and titrate with EDTA until the solutionchanges from red
26、 to clear blue.8.2.1 Calculate the molarity of the EDTA solution, M2,asfollows:M25 V1M1/V2(2)where:V1= volume of ZnCl2solution, mL, andV2= volume of EDTA solution, mL.8.3 Bismuth Nitrate, Standard Solution (0.05 M)Pipet 24mL of 0.05 M EDTA into a 250-mL Erlenmeyer flask, add 75mL of distilled water,
27、 neutralize with concentrated NH4OH toa pink end point with phenolphthalein, and then add 15 mL ofconcentrated formic acid. After cooling to room temperature,titrate with 0.05 M bismuth nitrate solution and xylenol orangefrom a yellow to a pink end point.8.3.1 Calculate the molarity, M3, of the Bi(N
28、O3)3solution asfollows:M35V3M2V4(3)where:M3= molarity of Bi(NO3)3solution,V3= 24.0 mLM2= molarity of EDTA solution, andV4= volume of Bi(NO3)3solution, mL.9. Procedure9.1 Check the clarity of the drier. If not clear, centrifuge aportion of the sample until it is clear, keeping the centrifugetube stop
29、pered to prevent solvent evaporation.9.2 Place a few grams of the drier in a 50-mL Erlenmeyerflask fitted with a cork through which passes a dropping tubeand rubber bulb (or a medicine dropper) and obtain the totalweight. Into another Erlenmeyer flask, weigh by difference to0.5 mg, a specimen of the
30、 appropriate size: (a) 0.6 to 0.7 g for6% Zr, (b) 0.3 to 0.35 g for 12 % zirconium, and (c)proportionate amounts for more or less Zr. Add several glassbeads, 5 mL of concentrated H2SO4, and 10 mL of 30 % H2O2and heat on the hot plate until white fumes appear. Destroy allthe organic matter by further
31、 additions of hydrogen peroxide in10-mL increments.D3969 01 (2012)29.3 Cool (25 to 30C), add 75 mL of water, not less than 0.2gofNa2SO3and boil for 5 min (Note 4). Add to the warmsolution 25 mL of 0.05 M EDTA and heat to boiling.NOTE 4If the solution turns milky red after the addition of Na2SO3,boil
32、ing will make it clear. Sometimes a black precipitate forms at this timealso. Disregard it since it does not interfere with the endpoint.9.4 Allow the solution to cool and neutralize with concen-trated NH4OH to a pink end point using phenolphthaleinindicator. Add 15 mL of concentrated formic acid an
33、d aftercooling to room temperature in an ice bath, add 6 to 8 drops ofxylenol orange and titrate with standard Bi(NO3)3solutionfrom a yellow to a pink end point.NOTE 5Because the color of metal indicators (and some of their metalcomplexes) is affected by pH changes, the pH must be kept constantdurin
34、g titration by the recommended buffer during the titration.10. Calculation10.1 Calculate the percent of metal, A,(Note 6) present aszirconium as follows:A 5V4M22 V5M3!9.122S2(4)where:V4= volume of EDTA solution, mL.V5= volume of Bi(NO3)3solution, mL,9.122 = millimolar weight of zirconium 100, andS2=
35、 specimen weight, g.NOTE 6Zirconium driers may contain up to 5 % of the total metal ashafnium. However, the typical hafnium content would be 1.6 6 0.1 % ofthe total metal present. The rest would be zirconium. Based on supplierresults, there is no difference in the activity of hafnium versus zirconiu
36、min paints.11. Precision and Bias511.1 PrecisionThe precision estimates are based on aninterlaboratory study in which one operator in six differentlaboratories analyzed in duplicate on two different days twosamples of zirconium drier containing 6 and 12 % zirconium.The zirconium drier was a commerci
37、ally supplied sample. Theresults were analyzed statistically in accordance with PracticeE180, and the within-laboratory coefficient of variation wasfound to be 0.46 % relative at 12 df and the between-laboratories coefficient of variation was 1.61 % relative at 10df. Based on these coefficients, the
38、 following criteria should beused for judging the acceptability of results at the 95 %confidence levels:11.1.1 RepeatabilityTwo results, each the mean of dupli-cate determinations, obtained by the same operator on differentdays should be considered suspect if they differ by more than1.42 % relative.
39、11.1.2 ReproducibilityTwo results, each the mean of du-plicate determinations, obtained by operators in different labo-ratories should be considered suspect if they differ by morethan 5.0 % relative.11.2 BiasBias cannot be determined because there are noaccepted standards for zirconium in paint drie
40、rs.12. Keywords12.1 analysis; EDTA method; liquid driers; paint driers;zirconium drierASTM International takes no position respecting the validity of any patent rights asserted in connection with any item mentionedin this standard. Users of this standard are expressly advised that determination of t
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43、s have not received a fair hearing you shouldmake your views known to the ASTM Committee on Standards, at the address shown below.This standard is copyrighted by ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959,United States. Individual reprints (single or mul
44、tiple copies) of this standard may be obtained by contacting ASTM at the aboveaddress or at 610-832-9585 (phone), 610-832-9555 (fax), or serviceastm.org (e-mail); or through the ASTM website(www.astm.org). Permission rights to photocopy the standard may also be secured from the ASTM website (www.astm.org/COPYRIGHT/).5Supporting data have been filed at ASTM International Headquarters and maybe obtained by requesting Research Report RR:D01-1031.D3969 01 (2012)3
