ASTM_D_1366_-_86_2019.pdf

Designation:D136686(Reapproved 2019)Standard Practice forReporting Particle Size Characteristics of Pigments1This standard is issued under the fixed designation D1366;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 practice for reporting the fineness characteristics ofpigments is designed to apply in most cases where well-knownmethods for determining these particle size characteristics inthe subsieve range are employed,such as microscopic,sedimentation,and turbidimetric methods;and partially toabsorption and permeability methods.1.2 Laminar,plate-like pigments and composite pigmentshaving a definite bimodal distribution are not considered withinthe scope of this practice.1.3 ParametersThe fineness characteristics are reported inthe following three parameters:1.3.1 Particle Size Parameter.1.3.2 Coarseness ParameterA parameter descriptive ofthe coarseness character of the pigment,making use of alimiting value in the subsieve range similar to that used in thesieve ranges.1.3.3 Dispersion ParameterA parameter descriptive ofthe uniformity of the particle size distribution.1.4 This standard does not purport to address all of thesafety concerns,if any,associated with its use.It is theresponsibility of the user of this standard to establish appro-priate safety,health,and environmental practices and deter-mine the applicability of regulatory limitations prior to use.1.5 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:2E20 Practice for Particle Size Analysis of Particulate Sub-stances in the Range of 0.2 to 75 Micrometres by OpticalMicroscopy(Withdrawn 1994)33.Terminology3.1 Definitions:3.1.1 particle size parameter(specific surface diameter,SSD),ndiameter d3used elsewhere in ASTM test methods.This parameter is the same as that frequently reported as“Average Particle Size by Surface Mean,”and“SpecificParticle Size,”and is defined as follows:SSD5(d3f/(d2f(1)where:SSD=specific surface diameter,m,d=mean class size,m,andf=frequency.Therefore the SSD is the diameter of a sphere having thespecific surface characteristic of the pigment.The true specificsurface of all pigments involves a shape factor.Report SSDwhether or not the effect of shape has been considered in thecalculations.Presumably,as the effect of shape is betterunderstood,it will figure more and more in calculationsinvolving particle size,but in the meantime it will of necessitybe ignored in many cases.3.1.2 coarseness parameter(CP),nthat diameter,ex-pressed in micrometres,below which 99.5%of the pigmentfalls.3.1.3 dispersion parameter(DP),nthe ratio of the mi-crometre size within which 50%of the pigment lies,to the1This practice is under the jurisdiction of ASTM Committee D01 on Paint andRelated Coatings,Materials,and Applications and is the direct responsibility ofSubcommittee D01.31 on Pigment Specifications.Current edition approved Oct.1,2019.Published October 2019.Originallyapproved in 1955.Last previous edition approved in 2012 as D1366 86(2012).DOI:10.1520/D1366-86R19.2For 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.1 specific surface diameter,SSD.The larger the DP number,thegreater the dispersion parameter and the lower the uniformity.Report the dispersion parameter in all cases when a distributioncurve can be prepared from the original data.The dispersionparameter cannot be calculated from data obtained by absorp-tion or permeability methods.Determine as follows:3.1.3.1 Prepare a cumulative-size distribution curve on3-phase log paper,using the vertical axis for the percent fallingbelow the size indicated,and the horizontal axis(log scale)fordiameter in micrometres.Use the upper class limit correspond-ing to the cumulative weight per