ASTM_D_716_-_86_2012.pdf

Designation:D71686(Reapproved 2012)Standard Test Methods forEvaluating Mica Pigment1This standard is issued under the fixed designation D716;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.1.Scope1.1 These test methods cover the evaluation of mica pig-ment.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 standard does not purport to address all of thesafety concerns associated with its use.It is the responsibilityof the user of this standard to establish appropriate safety andhealth practices and determine the applicability of regulatorylimitations prior to use.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 PigmentsE11 Specification for Woven Wire Test Sieve Cloth and TestSieves3.Significance and Use3.1 These test methods are used to determine apparentdensity of mica pigments and the grit level.This information issignificant to the user of mica pigments for inclusion incoatings.APPARENT DENSITY4.Apparatus4.1 VolumeterA Scott volumeter or similar apparatusmodified as follows:The screen used shall conform to therequirements of a No.40(425-m)sieve as prescribed inSpecification E11.The funnel below the screen shall bereplaced by a conical funnel having a bottom opening 25 mm(1 in.)in diameter.It may be found necessary to replace the topglass baffle with one that is longer to ensure that all of the siftedmica is caught.5.Procedure5.1 Transfer convenient quantities of the mica pigment tothe funnel of the modified volumeter and brush the pigmentthrough the screen with a camel-hair brush until the receiver isslightly more than full.Scrape off the excess and weigh thepigment.Care must be taken not to jar the apparatus during theprocedure.6.Calculation6.1 Calculate the apparent density of the mica pigment andconvert to pounds per cubic foot.7.Report7.1 Report the mean of three determinations as the apparentdensity of the mica pigment.8.Reproducibility of Results8.1 The mean of the three determinations should checkwithin 5%.MOISTURE AND OTHER VOLATILE MATTER9.Procedure9.1 Determine the moisture and other volatile matter inaccordance with Test Methods D280.GRIT10.Apparatus10.1 Beaker,600-mL,low-form.10.2 Metal TubingAn L-shape metal tube(Fig.1)6.4 mm(14in.)in outside diameter with a foot 25 mm(1 in.)in length.The foot of the tube shall be drilled to 4.4 mm(0173 in.)(No.17 drill)in inside diameter for a depth of 12.7 mm(12in.).Thetube shall be placed in the beaker with the long arm in thevertical position,and the foot of the L parallel to the bottom ofthe beaker and perpendicular to the radius of the bottom at apoint such that there is about 1.5-mm(116-in.)clearancebetween the tubing and both the bottom and side of the beaker.The center of the foot shall be placed 90 from the lip of thebeaker.1These test methods are under the jurisdiction of ASTM Committee D01 onPaint and Related Coatings,Materials,and Applications and are the directresponsibility of Subcommittee D01.31 on Pigment Specifications.Current edition approved Nov.1,2012.Published November 2012.Originallyapproved in 1943.Last previous edition approved in 2007 as D716 86(2007).DOI:10.1520/D0716-86R12.2For 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 11.Procedure11.1 Transfer 10 g of the sample to the 600-mL beaker,add100 mL of water,and swirl the beaker until the mica isdispersed.Insert the metal tubing into the beaker as describedin 10.2 and connect the upper end to a water faucet.Regulatethe flow of water by a constant head to a rate of 800 mL/minover the lip of the beaker.When the elutriation has progressedso that the body of the water in the beaker is clear,stop theflow,and lower the water level to prevent spilling.11.2 Swirl the beaker again to bring the remaining micapigment into suspension and repeat the elutriation procedure asdescribed in 11.1 three times.After final clearing,decant partof the water,and filter the residue.Transfer the paper andresidue to a weighed crucible,and ash slowly,cool,and weigh.12.Calculation12.1 Calculate the percent grit,G,as follows:G,%5A 2 B!/S#3100(1)where:A=ash,g,B=filter paper ash,g,andS=sample used,g.COARSE PARTICLES13.Procedure13.1 Determine the course particles in accordance with TestMethods D185.COLOR14.Standard Pigments14.1 Standard Mica Pigment.14.2 Standard Zinc O