ASTM_D_3619_-_77_1996e1.pdf

Designation:D 3619 77(Reapproved 1996)e1An American National StandardStandard Specification forAluminum Silicate Pigments(Anhydrous)1This standard is issued under the fixed designation D 3619;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(e)indicates an editorial change since the last revision or reapproval.e1NOTEKeywords were added editorially in May 1996.1.Scope1.1 This specification covers the white pigments that consistsubstantially of anhydrous(calcined)natural aluminum sili-cates2(of the 1+1 layer type)and are restricted to thoseminerals which conform to the chemical compositional limitsprescribed herein and which can be suitably processed to whatis known as paint pigment quality.2.Referenced Documents2.1 ASTM Standards:D 281 Test Method for Oil Absorption of Pigments bySpatula Rub-Out3D 718 Test Methods for Analysis of Aluminum SilicatePigment4D 1203 Test Methods for Volatile Loss from Plastics UsingActivated Carbon Methods5D 1483 Test Method for Oil Absorption of Pigments byGardner-Coleman Method3D 2448 Test Method for Water-Soluble Salts in Pigments byMeasuring the Specific Resistance of the Leachate of thePigment4D 3360 Test Method for Particle Size Distribution by Hy-drometer of the Common White Extender Pigments4E 70 Test Method for pH of Aqueous Solutions with theGlass Electrode63.Composition and Properties3.1 PreparationThe pigment shall be made by grinding,milling,washing,purifying,or otherwise processing,naturalhydrous aluminum silicates followed by heat treatment(calci-nation)sufficient to reduce the residual percent loss on ignitionto a maximum of 0.5%and otherwise conforming to thecomposition requirements(weight percent)given in Table 1.3.2 pHThe pH of a water slurry of the pigment shall bewithin a range from 4.5 to 5.5 unless otherwise agreed uponbetween the purchaser and the seller.3.3 Water-Soluble MatterThe water-soluble matter shallbe not more than 0.60%.3.4 Wet-Sieve ResidueThe pigment shall contain no morethan 0.02%wet-sieve residue retained on a 45 m(No.325)sieve(grit or coarse particles)except as may be agreed uponbetween the purchaser and the seller.3.5 Brightness(Color)The brightness(color reflectance)shall conform to the following requirements:3.5.1 The brightness shall be not less than 90%nor morethan 92%expressed as percent reflectance of standard illumi-nant C at 457 nm compared to a freshly smoked magnesiumoxide surface by means of an accepted integrating spherereflectance spectrophotometer or a monochromatic reflectancemeter,or3.5.2 The color may be specified by actual determination ofdominant wavelength,hue,and spectral efficiency as can becalculated from the tristimulus integration of the reflectancecurve,or3.5.3 The color shall be equal,within agreed upon toler-ances,to that of a reference standard agreed upon between thepurchaser and the seller.3.6 Oil AbsorptionThe oil absorption shall be within therange from 40 to 60 g/100 g as determined by the spatularub-out test(Test Method D 281)or within a range from 60 to80 g/100 g as determined by the Gardner-Coleman test method1This specification is under the jurisdiction of ASTM Committee D-1 on Paintand Related Coatings,Materials,and Applications and is the direct responsibility ofSubcommittee D01.31 on Pigment Specification.Current edition approved Nov.10,1977.Published January 1978.2Synonymous terms are kaolinite and china clay.3Annual Book of ASTM Standards,Vol 06.01.4Annual Book of ASTM Standards,Vol 06.03.5Annual Book of ASTM Standards,Vol 08.01.6Annual Book of ASTM Standards,Vol 15.05.TABLE 1 Pigment Composition Requirements(Percent by Weight)NOTE1The major constituents shown in the analysis are combined ascomplex aluminum silicate and do not exist as free oxides.IdealTypicalRangeMaxAluminum oxide,Al2O3,%45.9144.443-49A.Silicon dioxide,SiO2,%54.0952.356-50B.Iron oxide,Fe2O3,%.0.10.Titanium dioxide,TiO2,%.2.02.5Calcium oxide,CaO,%.0.1Sodium oxide,Na2O,%.0.1Potassium oxide,K2O,%.0.1Other oxides,%.0.1Free moisture(105C),%.0.50.5Loss on ignition(1000C),%.0.50.5Free silica(either amorphous or as crystal-line quartz),%1.0APermitting up to about 5%excess Al2O3,for example,as allophane.BPermitting up to about 5%excess SiO2,for example,but no more than 1%offree silica(SiO2)either amorphous or as crystalline quartz.1AMERICAN SOCIETY FOR TESTING AND MATERIALS100 Barr Harbor Dr.,West Conshohocken,PA 19428Reprinted from the Annual Book of ASTM Standards.Copyright ASTM(Test Method D 1483)(see 5.1.4).It may be noted thatreproducible test results using the spatula rub-out test method(Test Method D 281)are found to be very difficult to obtainbecause of a very high electrostatic charge imparted to theanhydrous pigment during the rub-out procedure.Although aspatula rub-out test result can be obtained,it has been found byexperience that much more reproducible res