1、Designation: D2218 67 (Reapproved 2012)Standard Specification forMolybdate Orange Pigments1This standard is issued under the fixed designation D2218; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last revision. A numb
2、er in parentheses indicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.This standard has been approved for use by agencies of the Department of Defense.1. Scope1.1 This specification covers the pigment known as molyb-date
3、orange.1.2 The values stated in SI units are to be regarded asstandard. The values given in parentheses are for informationonly.1.3 The following hazard caveat applies to the test methodportion of this specification only. This standard does notpurport to address all of the safety concerns, if any, a
4、ssociatedwith its use. It is the responsibility of the user of this standardto establish appropriate safety and health practices anddetermine the applicability of regulatory limitations prior touse.2. Referenced Documents2.1 ASTM Standards:2D126 Test Methods for Analysis of Yellow, Orange, andGreen
5、Pigments Containing Lead Chromate and Chro-mium Oxide GreenD185 Test Methods for Coarse Particles in PigmentsD235 Specification for Mineral Spirits (Petroleum Spirits)(Hydrocarbon Dry Cleaning Solvent)D387 Test Method for Color and Strength of ChromaticPigments with a Mechanical MullerD523 Test Meth
6、od for Specular GlossD600 Specification for Liquid Paint DriersD822 Practice for Filtered Open-Flame Carbon-Arc Expo-sures of Paint and Related CoatingsD1210 Test Method for Fineness of Dispersion of Pigment-Vehicle Systems by Hegman-Type GageE97 Method of Test for Directional Reflectance Factor,45-
7、Deg 0-Deg, of Opaque Specimens by Broad-BandFilter Reflectometry (Withdrawn 1991)32.2 Federal Specification:TT-R-266 Resin, Alkyd; Solutions43. Composition and Properties3.1 Dry PigmentThe pigment shall be a product made bythe chemical coprecipitation of lead chromate and lead molyb-date, with or wi
8、thout admixtures of other insoluble compoundsof lead or other materials used in manufacture to control certainproperties. The pigment shall conform to the requirements forchemical composition as prescribed in Table 1.3.2 The mass color and character of the tint formed by amixture with a white pigmen
9、t shall be the same as, and thestrength shall be within mutually agreed upon limits of astandard acceptable to both the purchaser and the seller.3.3 When mutually agreed upon between the purchaser andthe seller as being essential to the end use of the pigment,resistance to loss of gloss, chalking, a
10、nd color change shall betested as specified in 5.1.6 The exposed panel shall show nochalking, a loss of not more than 10 % of the original gloss,and a color change difference of not more than three units.4. Sampling4.1 Two samples shall be taken at random from differentpackages from each lot, batch,
11、 days pack, or other unit ofproduction in a shipment. When no markings distinguishingbetween units of production appear, samples shall be takenfrom different packages in the ratio of two samples for each4540 kg (10 000 lb), except that for shipments of less than10 000 lb two samples shall be taken.
12、At the option of thepurchaser, the samples may be tested separately, or samplesfrom the same production unit may be blended in equalquantities to form a composite sample.5. Test Methods5.1 Tests shall be conducted in accordance with the follow-ing ASTM test methods:1This specification is under the j
13、urisdiction of ASTM Committee D01 on Paintand Related Coatings, Materials, and Applications and is the direct responsibility ofSubcommittee D01.31 on Pigment Specifications.Current edition approved June 1, 2012. Published August 2012. Originallyapproved in 1963. Last previous edition approved in 200
14、6 as D2218 - 67 (2006).DOI: 10.1520/D221867R12.2For 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 standards Document Summary page onthe ASTM website.3The last appr
15、oved version of this historical standard is referenced onwww.astm.org.4Available from Standardization Documents Order Desk, DODSSP, Bldg. 4,Section D, 700 Robbins Ave., Philadelphia, PA 19111-5098, http:/www.dodssp.daps.mil.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Consh
16、ohocken, PA 19428-2959. United States15.1.1 Chemical Analysis of Lead ChromateProceed inaccordance with the Lead Chromate section of Test MethodsD126. The alternative procedure is not applicable.5.1.2 Chemical Analysis of Lead Molybdate and TotalMolybdenumWeigh to 1 mg about 1-g sample of pigmentint
17、o a 250-mL beaker. Add 20 mL of sulfuric acid (H2SO4,1+1) and heat to light fumes. Cool the solution, dilute to 150mL, filter, and wash with water. To reduce chromate, addfreshly prepared sulfurous acid (H2SO3) until the solution turnsgreen, and then add several millilitres in excess. Boil thesoluti
18、on until excess H2SO3is removed. Cool the solution to 5to 10C, and add 30 mL of a 2 % solution of alphabenzoino-xime in alcohol slowly, with stirring. Add sufficient brominewater to tint the solution a pale yellow, and then add a fewmore millilitres of the alphabenzoinoxime reagent. After 15min at 5
19、 to 10C, filter the solution through very thin, mediumpaper. Then wash the solution with cold H2SO4(1+100)containing 25 to 50 mL of prepared alphabenzoinoxime re-agent per litre. Place the precipitate in a platinum crucible, charcautiously, then ignite to constant weight at 500C, and weighas molybde
20、num oxide (MoO3). Calculate weight percent leadmolybdate (PbMoO4), M, as follows:M 5 A 3255!/S (1)where:A = weight of MoO3obtained, g, andS = specimen weight, g.5.1.3 Coarse ParticlesTest Methods D185.5.1.4 Mass Color and Tinting StrengthTest Method D387.5.1.5 Moisture and Other Volatile MatterTest
21、MethodsD126.5.1.6 Resistance to Loss of Gloss, Chalking, and ColorChange:5.1.6.1 Prepare a test enamel consisting of ingredientsconforming to the applicable specifications in the followingproportions:Ingredient Weight %Molybdate orange sample 29.51Alkyd resin solutionA61.72Mineral spiritsB8.37Lead n
22、aphthenateC0.25Cobalt naphthenateC0.15_Total 100.0AConforming to Type III of U.S. Federal Specification TT-R-266.BSee Specification D235.CSee Class B of Specification D600.5.1.6.2 Give the enamel three passes through a moderatelytight roller mill setting to give a fineness of grind, as deter-mined f
23、ollowing Test Method D1210, of 1.5 mils (40 m) orless. Apply the enamel to duplicate flat metal panels by sprayor applicator to complete hiding, and allow to dry 72 h.Measure the gloss at 60 in accordance with Test MethodD523. Measure the directional reflectance of the coating inaccordance with Test
24、 Method E97. Subject the coated panelsfor 168 h to accelerated weathering under the conditionsprescribed in Practice D822. Examine the exposed coating forchalking. Wash the exposed panel under running water with athoroughly degreased lambs wool pad to remove scum or dirt.Wipe off the water with clea
25、n cheesecloth and dry the panel for2 h. Calculate the loss of gloss from gloss measurements madebefore and after exposure. After exposure, determine thedirectional reflectance for each panel as described in TestMethod E97. Estimate the color change or lightness-differenceestimate (DL) as follows:DL
26、5 KY212 2 Y112! (2)where:Y1= luminous directional reflectance of the panel measuredbefore exposure,Y2= reflectance measured after exposure, andK = 100 when the reflectances are expressed in decimalfractions or 10 if reflectances are expressed in per-cent.The color change for the coating shall be the
27、 mean obtainedfor the two panels.56. Keywords6.1 lead; molybdate chrome/molybdate; molybdate orange;pigment5The method of determining the lightness-difference estimate is described indetail in example 4, “Photoelectric Tristimulus Colorimetry with Three Filters,”Circular C429, NBSCA, Nat. Bureau Sta
28、ndards.TABLE 1 Requirements for Chemical Composition%Min MaxChromium (calculated as PbCrO4) 70 .Molybdenum (calculated as PbMoO4) 8 .Total of all substances (including moisture andwater soluble compounds) other than insolublecompounds of lead. 12Moisture and other volatile matter . 1.5Coarse particl
29、es (total residue retained on a45-m (No. 325) sieve. 1.0Matter soluble in water . 1.0D2218 67 (2012)2ASTM 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 det
30、ermination of the validity of any such patent rights, and the riskof infringement of such rights, are entirely their own responsibility.This standard is subject to revision at any time by the responsible technical committee and must be reviewed every five years andif not revised, either reapproved o
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32、at your comments 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
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