Designation:D2448−85(Reapproved2012)StandardTestMethodforWater-SolubleSaltsinPigmentsbyMeasuringtheSpecificResistanceoftheLeachateofthePigment1ThisstandardisissuedunderthefixeddesignationD2448;thenumberimmediatelyfollowingthedesignationindicatestheyearoforiginaladoptionor,inthecaseofrevision,theyearoflastrevision.Anumberinparenthesesindicatestheyearoflastreapproval.Asuperscriptepsilon(´)indicatesaneditorialchangesincethelastrevisionorreapproval.1.Scope1.1Thistestmethodcoversthedeterminationofthespecificresistanceoftheaqueousleachatefromapigmentasanindexofwater-solublesaltcontent.Thistestmethodisapplicabletowhitepigmentsandcoloredpigments(organicandinorganic).Thewater-solublesaltscontentisafunctionofthespecificresistanceofthesolutionformedbyextractingthepigmentwithwater.1.2Thistestmethodisbasedonawatertopigmentratioof9+1.Theleachateyield(minimum160mL)sufficientforrinsingthecylinderdipcellandthermometerplusthemini-mum80mLrequiredforthemeasurementtodeterminethequantityofpigmenttobeused.1.3ThevaluesstatedinSIunitsaretoberegardedasstandard.Nootherunitsofmeasurementareincludedinthisstandard.1.4Thisstandarddoesnotpurporttoaddressallofthesafetyconcerns,ifany,associatedwithitsuse.Itistheresponsibilityoftheuserofthisstandardtoestablishappro-priatesafetyandhealthpracticesanddeterminetheapplica-bilityofregulatorylimitationspriortouse.2.ReferencedDocuments2.1ASTMStandards:2D1193SpecificationforReagentWater3.SummaryofTestMethod3.1Aweighedquantityofpigmentisaddedtowaterandboiled.Forhydrophobicpigmentsmethylalcoholisusedtofacilitatewetting.Afterfiltration,thespecificresistanceofthefiltrateisdeterminedusingaconductivitybridge.4.SignificanceandUse4.1Thistestmethodprovidesareliablemeansforthedeterminationoftherelativeamountsofthesesaltswhencomparingdifferentlotsofthesamepigmentgrade.Water-solublesaltsalsoaffectthewaterresistanceandblisterresis-tanceofcoatings,especiallyprimersforsteel.Conductivitymeasurements,however,cannotbeusedastheonlymethodtodetermineandcomparetheamountofwate...
