ASTM_D_6280_-_98_2020.pdf

Designation:D628098(Reapproved 2020)Standard Specification forZinc Phosphate Pigments1This standard is issued under the fixed designation D6280;the number immediately following the designation indicates the year oforiginal adoption or,in the case of revision,the year of last revision.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 specification covers three types of pigments com-mercially known as zinc phosphate each of which may or maynot be available in specific grades delineated by particle size oroil absorption.1.1.1 Type IZinc Phosphate,dihydrate predominant.1.1.2 Type IIZinc Phosphate,dihydrate tetrahydrate mix-ture.1.1.3 Type IIIZinc Phosphate,tetrahydrate predominant.1.2 The values stated in SI units are to be regarded asstandard.No other units of measurement are included in thisstandard.1.3 This international standard was developed in accor-dance with internationally recognized principles on standard-ization established in the Decision on Principles for theDevelopment of International Standards,Guides and Recom-mendations issued by the World Trade Organization TechnicalBarriers to Trade(TBT)Committee.2.Referenced Documents2.1 ASTM Standards:2D153 Test Methods for Specific Gravity of PigmentsD185 Test Methods for Coarse Particles in PigmentsD280 Test Methods for Hygroscopic Moisture(and OtherMatter Volatile Under the Test Conditions)in PigmentsD281 Test Method for Oil Absorption of Pigments bySpatula Rub-outD1193 Specification for Reagent WaterD1208 Test Methods for Common Properties of CertainPigmentsD1210 Test Method for Fineness of Dispersion of Pigment-Vehicle Systems by Hegman-Type GageD2448 Test Method for Water-Soluble Salts in Pigments byMeasuring the Specific Resistance of the Leachate of thePigment3.Significance and Use3.1 Zinc phosphate functions as both a chemical and apigment.As a pigment it is used in a variety of applicationsincluding that of corrosion inhibiting paints.4.Composition and Properties4.1 Zinc phosphate pigment is a white corrosion inhibitingpigment consisting either predominately of zinc phosphatedihydrate(Zn3(PO4)22H2O)or a mixture of zinc phosphatedihydrate and zinc phosphate tetrahydrate(Zn3(PO4)24H2O)or predominately of zinc phosphate tetrahydrate which is freefrom extenders,diluents,and other pigments.4.2 Zinc phosphate shall be a chemically prepared pigmentand shall be of such type and grade as to conform to therequirements prescribed in Table 1.They shall additionally befree of extenders,modifiers,diluents,alteration of stoichiomet-ric chemical structure,co-reacted precipitates,and carbona-ceous material.4.3 The desired properties of the pigment,other than asherein indicated,shall be subject to mutual agreement betweeninterested parties and shall be based upon a satisfactory matchbetween any submitted sample and a previously agreed uponreference sample.5.Classification5.1 Type Iwhich consists predominately of zinc phosphatedihydrate(Zn3(PO4)22H2O)and exhibits a differentiating losson ignition of the dried pigment at 600C between 8.5 and 10.0weight%.5.2 Type IIwhich consists essentially of a mixture of zincphosphate dihydrate(Zn3(PO4)22H2O)and Zinc PhosphateTetrahydrate(Zn3(PO4)24H2O)and exhibits a differentiatingloss on ignition of the dried pigment at 600C between 10.0and 14.0 weight%.5.3 Type IIIwhich consists predominately of zinc phos-phate tetrahydrate(Zn3(PO4)24H2O)and exhibits a differenti-ating loss on ignition of the dried pigment at 600C between14.0 and 18.0 weight%.1This specification is under the jurisdiction 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 1,2020.Published July 2020.Originally approvedin 1998.Last previous edition approved in 2014 as D6280 98(2014).DOI:10.1520/D6280-98R20.2For 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 International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United StatesThis international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for theDevelopment of International Standards,Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade(TBT)Committee.6.Sampling6.1 Two 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 ratio of two samples for each 5000kg,except for those shipments of less than 5000 kg where twosamples shall be