1、Designation:D7986(Reapproved 2014)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 origina
2、ladoption 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.
3、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 zi
4、nc 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.2.Referenced Documents2.1 ASTM Standards:2D185 Test Methods for Coarse Particles in PigmentsD280 Test Methods for Hygroscopic Moisture(and Ot
5、herMatter 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
6、 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 Particula
7、te Sub-stances in the Range of 0.2 to 75 Micrometres by OpticalMicroscopy(Withdrawn 1994)33.Significance and Use3.1 Zinc oxide functions as both a chemical and a pigment.It is used in a variety of applications including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 pr
8、otection,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
9、 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 proces
10、s 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
11、 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:Pigment
12、,%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 match a referencesample mutua
13、lly agreed upon by the purchaser and the seller.The most frequently specified properties are oil absorption,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 Sp
14、ecifications.Current edition approved Dec.1,2014.Published December 2014.Originallyapproved in 1921.Last previous edition approved in 2009 as D79 86(2009).DOI:10.1520/D0079-86R14.2For referenced ASTM standards,visit the ASTM website,www.astm.org,orcontact ASTM Customer Service at serviceastm.org.For
15、 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 S
16、tates1 tinting strength,and particle shape.Appropriate test methodsare listed in Section 6.In the event that either an acicular typeor a nodular(spherical)type of zinc oxide is desired,theparticle shape shall be determined by examining or photo-graphing microscopic mounts(1000 or more)of the sampleand the mutually agreed upon standard that are to be preparedas specified in Practice E20.5.Sampling5.1 Two samples shall be taken at random from differentpackages from each lot,batch,days pack,or othe