Designation:D281−12StandardTestMethodforOilAbsorptionofPigmentsbySpatulaRub-out1ThisstandardisissuedunderthefixeddesignationD281;thenumberimmediatelyfollowingthedesignationindicatestheyearoforiginaladoptionor,inthecaseofrevision,theyearoflastrevision.Anumberinparenthesesindicatestheyearoflastreapproval.Asuperscriptepsilon(´)indicatesaneditorialchangesincethelastrevisionorreapproval.ThisstandardhasbeenapprovedforusebyagenciesoftheDepartmentofDefense.1.Scope*1.1Thistestmethodcoversthedeterminationoftheoilabsorptionofpigmentsbythespatularub-outtechnique.1.2ThevaluesstatedinSIunitsaretoberegardedasstandard.Thevaluesgiveninparenthesesareforinformationonly.1.3Thisstandarddoesnotpurporttoaddressallofthesafetyconcerns,ifany,associatedwithitsuse.Itistheresponsibilityoftheuserofthisstandardtoestablishappro-priatesafetyandhealthpracticesanddeterminetheapplica-bilityofregulatorylimitationspriortouse.2.ReferencedDocuments2.1ASTMStandards:2D1483TestMethodforOilAbsorptionofPigmentsbyGardner-ColemanMethod3.SummaryofTestMethod3.1Astiff,putty-likepasteisformedbythedropwiseadditionoflinseedoiltopigmentthatisbeingthoroughlyrubbedwithaspatula.Theamountofoilrequiredtoproducetheendpointisusedtocalculateanoilabsorptionvalue.4.SignificanceandUse4.1Theoilabsorptionvalueobtainedbythistestmethodgivesinformationaboutthevehicledemandofthepigmentwhenitisusedinapigmentpaste.Oilabsorptionvaluescanbeusedtocharacterizepigmentsorbatchesofagivenpigment.4.2ThistestmethoddiffersfromTestMethodD1483inthatD1483involvesonlyagentlestirringandfoldingofthepigment,whereasthistestmethodrequiresathoroughrubbingaction.Becausetheendpointsaredifferent,thevaluesobtainedfromthetwotestmethodsgenerallydiffer.5.ApparatusandMaterials5.1Balance,capableofweighingto0.001g.5.2DroppingBottle,fittedwithground-inpipetandrubberbulborburet,graduatedin0.1-mLdivisions.5.3SmoothGlassRub-upPlateorMarbleSlab(glassshouldhaveasurfacesimilartoHooverMullerPlates).5.4Spatula,sharp-edged,steel,havingabladeof15or20mmby100mm(1⁄2or3⁄4by4i...
