ASTM_D_476_-_15.pdf

Designation:D47615Standard Classification forDry Pigmentary Titanium Dioxide Products1This standard is issued under the fixed designation D476;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.This standard has been approved for use by agencies of the U.S.Department of Defense.1.Scope1.1 This classification describes eight types of dry pigmen-tary titanium dioxide products,grouped by composition,typi-cal end use application,and some performance properties.1.2 The values stated in SI units are to be regarded asstandard.No other units of measurement are included in thisstandard.2.Referenced Documents2.1 ASTM Standards:2D34 Guide for Chemical Analysis of White PigmentsD153 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 PigmentsD1394 Test Methods for Chemical Analysis of White Tita-nium PigmentsD2448 Test Method for Water-Soluble Salts in Pigments byMeasuring the Specific Resistance of the Leachate of thePigmentD3720 Test Method for Ratio of Anatase to Rutile inTitanium Dioxide Pigments by X-Ray Diffraction3.Significance and Use3.1 This classification is given as an aid in determining thefitness for use of a titanium dioxide pigment for a coatingapplication.It is limited to dry,hiding pigments.It excludespigment dispersions,and non-hiding specialty titanium dioxideproducts.4.Basis for Classification4.1 Titanium dioxide pigments can differ in many ways,including composition and performance.This classificationoutlines differences between pigment types that should beconsidered when selecting a product for a coating application.A minimum number of properties are given to highlight majordifferences,while allowing maximum flexibility.5.Composition and Properties5.1 Titanium Dioxide Pigments,should conform to therequirements for composition prescribed in Table 1.They arechemically prepared pigments consisting of anatase or rutiletitanium dioxide with or without modifications with water-insoluble oxides of aluminum,silicon,zinc,etc.,or otheragents;these reagent materials are introduced specifically toimprove those properties for which the pigment is used.Thetitanium dioxide pigments shall be free of extenders such asbarium sulfate,clay,magnesium silicate,whiting,etc.5.2 The desired properties of the pigment,other than asherein indicated,shall be subject to agreement between thepurchaser and the seller and shall be based on a satisfactorymatch between the submitted pigment sample and a previouslyagreed upon reference sample(see 6.1.6).6.Test Methods6.1 Tests shall be conducted in accordance with the follow-ing test methods.Test procedures not covered by ASTM testmethods shall be mutually agreed upon between the purchaserand the seller.6.1.1 Chemical AnalysisGuide D34 or Test MethodsD1394.6.1.2 Specific GravityTest Methods D153.6.1.3 Coarse ParticlesTest Methods D185.6.1.4 MoistureTest Methods D280.6.1.5 Matter Soluble in Water,Specific ResistanceTestMethod D2448.The measured specific resistance of the aque-ous leachage from the pigment is an index of the level ofwater-soluble salts.6.1.6 Chalking ResistanceIt is recommended that pur-chaser and seller agree upon standards and methods of testsuitable for their requirements(see 5.2).Comparison in a goodquality exterior air-dry alkyd enamel(trade sales or industrial)and exposure in Florida at 45 facing south are recommended.Chalking differences are minimized by less durable vehicles,while required exposure times are prolonged by more durable1This classification 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 Feb.1,2015.Published February 2015.Originallyapproved in 1938.Last previous edition approved in 2013 as D476 13.DOI:10.1520/D0476-15.2For 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 States1 TABLE 1 Classification of Dry,Pigmentary Titanium Dioxide PigmentsTypical PropertiesClassification TypeIIIIIIIVVVIVIIVIIIASTMStandardsCrystal typeanataseArutilerutilerutilerutilerutilerutilerutileD3720Chalkingresistance,relativefree chalkinglow-mediummediumhighhighmedium-highmedium-highvery highTypical end useapplication(s)white exteriorhouse paint andinterior useslow-medium%PVChigh%PVCexterior coatingsrequiring excellentdurabilityexterior coatingsrequiring excel