1、Designation: D478 02 (Reapproved 2012)Standard Specification forZinc Yellow (Zinc Chromate) Pigments1This standard is issued under the fixed designation D478; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last revisio
2、n. A number 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 pigments commercial
3、lyknown as zinc yellow (zinc chromate).1.2 Two types are included:1.2.1 Type IHigh-purity, low sulfate and chloride content.1.2.2 Type IIRegular grade.1.3 The values stated in SI units are to be regarded asstandard. The values given in parentheses are for informationonly.2. Referenced Documents2.1 A
4、STM Standards:2D185 Test Methods for Coarse Particles in PigmentsD387 Test Method for Color and Strength of ChromaticPigments with a Mechanical MullerD444 Test Methods for Chemical Analysis of Zinc YellowPigment (Zinc Chromate Yellow)3. Significance and Use3.1 Zinc yellow is used in rust-inhibiting
5、protective coatingsand metal primers for ferrous and non-ferrous metals.4. Composition and Properties4.1 Dry PigmentThe pigment shall be a reaction precipi-tate of soluble chromates and a suitable zinc compound andshall be free of extenders, carbonates, and organic color in anyform. The pigment shal
6、l conform to the requirements forcomposition prescribed in Table 1.4.2 The mass color and character of the tint and the tintingstrength formed by a mixture with a white pigment shall bewithin mutually agreed upon limits of a standard acceptable toboth the purchaser and the seller.5. Sampling5.1 Two
7、samples shall be taken at random from differentpackages from each lot, batch, 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 each4545 kg (10 000 lb),
8、 except that for shipments of less than10 000 lb two samples shall be taken. At the option of thepurchaser, the samples may be tested separately or afterblending in equal quantities the samples from the sameproduction unit to form a composite sample.6. Test Methods6.1 Tests shall be conducted in acc
9、ordance with the follow-ing ASTM test methods:6.2 Chemical AnalysisTest Methods D444.6.3 Coarse ParticlesTest Methods D185.6.4 Mass Color and Tinting StrengthTest Method D387.7. Keywords7.1 chromatic; inhibitor metal primer; pigment; zinc chro-mate; zinc yellow1This specification is under the jurisd
10、iction 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 1938. Last previous edition approved in 2006 as
11、D478 02 (2006).DOI: 10.1520/D0478-02R12.2For 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.Copyright ASTM Intern
12、ational, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States1ASTM 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 determinati
13、on 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 or withdr
14、awn. Your comments are invited either for revision of this standard or for additional standardsand should be addressed to ASTM International Headquarters. Your comments will receive careful consideration at a meeting of theresponsible technical committee, which you may attend. If you feel that your
15、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 (single
16、 or multiple 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 (
17、www.astm.org/COPYRIGHT/).TABLE 1 Composition RequirementsType I Type IIZinc (calculated as ZnO), % 35 to 40 35 to 40Chromium (calculated as CrO3),min, %41 41Sulfates (calculated as SO3), max, % 0.20 3.0AChlorides (calculated as Cl), max, % 0.10 0.8AAlkaline salts (calculated as K2O), max, % 13 13Mat
18、ter insoluble in acetic acid(1+9) at 80C, max, %0.3 0.3Moisture and other volatile matter, max, % 1.0 1.0Coarse particles (total residue retained onNo. 325 (45-m) sieve), max, %1.0 1.0AThe maximum percent of sulfates or chlorides given in the table for Type IIpigment apply if only one or the other i
19、s present (for this purpose amounts of lessthan 0.05 % shall be disregarded). If both sulfates and chlorides are present, thesum of the percentages of each divided by its respective maximum permissiblepercentage (3.0 for SO3and 0.8 for Cl) shall not exceed 1.0. For example, if asample contains 1.8 % SO3(0.6 of the maximum for sulfates) and 0.3 % chlorides(0.4 of the maximum for chlorides), the sample just conforms to the maximumrequirements of the specification in this respect.D478 02 (2012)2
