Designation:D3721−05(Reapproved2011)StandardSpecificationforSyntheticRedIronOxidePigment1ThisstandardisissuedunderthefixeddesignationD3721;thenumberimmediatelyfollowingthedesignationindicatestheyearoforiginaladoptionor,inthecaseofrevision,theyearoflastrevision.Anumberinparenthesesindicatestheyearoflastreapproval.Asuperscriptepsilon(´)indicatesaneditorialchangesincethelastrevisionorreapproval.1.Scope1.1Thisspecificationcoverssyntheticredironoxideforuseinpaintsandcoatingsmanufacturedbyanyofthefollowing:1.1.1Calcinationofironsalts.1.1.2Precipitationfromironsalts.1.1.3Calcinationofsyntheticironoxide.1.1.4Productoforganicreduction.2.ReferencedDocuments2.1ASTMStandards:2D50TestMethodsforChemicalAnalysisofYellow,Orange,Red,andBrownPigmentsContainingIronandManga-neseD185TestMethodsforCoarseParticlesinPigmentsD280TestMethodsforHygroscopicMoisture(andOtherMatterVolatileUndertheTestConditions)inPigmentsD387TestMethodforColorandStrengthofChromaticPigmentswithaMechanicalMullerD1208TestMethodsforCommonPropertiesofCertainPigments3.CompositionandProperties3.1Thepigmentshallconformtothefollowingrequirements:Fe2O3,min,%96.0Moistureandothervolatilematter,max,%1.0OrganiccoloringmatternoneCoarseparticles(totalresidueretainedona45-µm(No.325)sieve)max,%1.0Mattersolubleinwater,max,%0.2pHvalue,min5.03.2Inasmuchasironoxidepigmentsareavailableinarangeofcolors,themasscolorand,ifdesiredbythepurchaser,thecharacterofthetintformedbymixturewithawhitepigmentshallbewithinmutuallyagreeduponlimitsofareferencesamplemutuallyagreeduponbetweenthesellerandthepurchaser.ThissampleshouldbetestedinaccordancewithTestMethodD387.4.Sampling4.1Twosamplesshallbetakenatrandomfromdifferentpackagesfromeachlot,batch,day’spack,orotherunitofproductioninashipment.Whennomarkingsdistinguishingbetweenunitsofproductionappearsamplesshallbetakenfromdifferentpackagesintheratiooftwosamplesforeach10000lb(5000kg),exceptthatforshipmentsoflessthan10000lbtwosamplesshallbetaken.Attheoptionofthepurchaser,thesamplesmaybetestedsepara...
