ASTM_D_79_-_86_2020.pdf

Designation:D7986(Reapproved 2020)American Association StateHighway and Transportation Officials StandardAASHTO No.:M124Standard Specification forZinc Oxide Pigments1This standard is issued under the fixed designation D79;the number immediately following the designation indicates the year of originaladoption or,in the case of revision,the year of last revision.Anumber in parentheses indicates the year of last reapproval.Asuperscriptepsilon()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 specification covers the pigments commerciallyknown as“zinc white”or zinc oxide.The pigments may bepurchased in the dry form or as a paste in oil.NOTE1Zinc oxides are used in many industries.For additionalinformation,see Classification D4295 and Test Methods D4315 fordescriptions of zinc oxide use in rubber compounding.1.2 The values stated in SI units are to be regarded as thestandard.The values given in parentheses are for informationonly.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:2D185 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-outD332 Test Method for Relative Tinting Strength of WhitePigments by Visual ObservationD1483 Test Method for Oil Absorption of Pigments byGardner-Coleman MethodD2745 Test Method for Relative Tinting Strength of WhitePigments by Reflectance MeasurementsD3280 Test Methods for Analysis of White Zinc PigmentsD4295 Classification for Rubber Compounding MaterialsZinc OxideD4315 Test Methods for Rubber Compounding MaterialZinc OxideE20 Practice for Particle Size Analysis of Particulate Sub-stances in the Range of 0.2 to 75 Micrometres by OpticalMicroscopy(Withdrawn 1994)33.Significance and Use3.1 Zinc oxide functions as both a chemical and a pigment.It is used in a variety of applications including rubber,paint,reprography,glass,chemicals,etc.In paint,it contributes tomildew protection,ultraviolet absorption,hiding power,andneutralization of acids formed upon oxidation of the paint film.4.Composition and Properties4.1 Dry Pigment,French ProcessIn the manufacture ofFrench process zinc oxide,metallic zinc is vaporized,either ina boiler or a refining column,and the resulting vapor is burnedin a controlled manner in an orifice.The fine particles of zincoxide are cooled enough to agglomerate and are collected by asystem of fabric bags.French process oxide shall conform tothe properties listed in Table 1.4.2 Dry Pigment,American ProcessIn the manufacture ofAmerican process zinc oxide,zinc ore is reduced in thepresence of a carbonaceous fuel.The resulting vapor is burnedin a combustion chamber,and the fine particles of zinc oxideare cooled enough to agglomerate and are collected by asystem of fabric bags.American process oxide shall conform tothe properties listed in Table 1.4.3 Paste in OilThe paste shall be made by thoroughlygrinding the specified pigment with linseed oil.As received itshall not be caked in the container and shall break up readily inoil to form a smooth paint of brushing consistency.The pasteshall conform to the following requirements: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 June 2020.Originallyapproved in 1921.Last previous edition approved in 2014 as D79 86(2014).DOI:10.1520/D0079-86R20.2For 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.3The last approved version of this historical standard is referenced onwww.astm.org.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.Pigment,%80 to 86Linseed oil,%14 to 20Moisture and other volatile matter,max,%0.5Coarse particles and skins(total residue retained on aNo.325(45-m)sieve),max,%of the dry pigment1.54.4 In such physical properties as are specified by thepurchaser,the pigment shall satisfactorily m