ASTM_D_332_-_87_2015.pdf

Designation:D33287(Reapproved 2015)Standard Test Method forRelative Tinting Strength of White Pigments by VisualObservation1This standard is issued under the fixed designation D332;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 This test method describes the procedure for determin-ing the relative tinting strength of white pigments by visualassessment of blue tints.1.2 This test method is applicable only for comparing thetest pigment with a reference standard of the same type andgrade.NOTE1Test Method D2745 describes a procedure for instrumentalevaluation of black tinted samples.1.3 The values stated in SI units are to be regarded as thestandard.The values given in parentheses are for informationonly.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 and health practices and determine the applica-bility of regulatory limitations prior to use.2.Referenced Documents2.1 ASTM Standards:2D262 Specification for Ultramarine Blue Pigment(With-drawn 2005)3D2745 Test Method for Relative Tinting Strength of WhitePigments by Reflectance Measurements3.Summary of Test Method3.1 Specified amounts of white pigment and blue tintingpigment are dispersed together in oil using a glass hand mulleror an automatic muller.Both the test and standard pigments aretreated identically.The pastes are drawn-down together on apanel and visually assessed for tinting strength.To obtain anumerical rating of tinting strength,dispersions with thestandard white pigment and more or less of the tinting pigmentare made until the lightness of the test pigment paste ismatched.The weight of the tinting pigment is used to calculaterelative tinting strength.4.Significance and Use4.1 This test method is used as a referee method and forquality control.The vehicle(oil)for preparing the dispersionsand the tinting pigment(ultramarine blue)are specified butother vehicles and tinting pigments can be used.Any suchchanges in the test method must be agreed upon between thepurchaser and the seller.4.2 The results obtained with a muller do not necessarilyagree with an industrial situation where different dispersingconditions exist.However,dispersing with a muller is a fastand relatively inexpensive way of testing tinting strength forroutine quality control.5.Apparatus5.1 Balance,laboratory-type,sensitive to 0.1 mg,equippedwith a counter-balanced watch glass.5.2 Buret,1-mL capacity,stopcock controlled,graduated in0.1-mL divisions,or other suitable dispensing apparatus with adelivery accurate to 0.05 mL.5.3 Glass Hand MullerAweighted glass hand muller withbeveled edge having a total weight of 6.8 kg(15 lb)and agrinding face of from 70 to 75 mm(234to 3 in.)in diameter.The face shall be free of blowholes and other imperfections andkept roughened by lightly grinding with No.303 optical emery,or its equivalent,and turpentine.5.4 Rubbing SurfaceA ground glass plate,at least 355 by510 mm(14 by 20 in.),the surface of which is kept roughenedby lightly grinding with No.303 optical emery,or itsequivalent,and turpentine.1This test method is under the jurisdiction of ASTM Committee D01 on Paintand Related Coatings,Materials,and Applications and is the direct responsibility ofSubcommittee D01.26 on Optical Properties.Current edition approved Dec.1,2015.Published December 2015.Originallyapproved in 1931.Last previous edition approved in 2011 as D332 87(2011).DOI:10.1520/D0332-87R15.2For 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 States1 5.5 Automatic Muller,automatic,4equipped with a weightthat exerts a permanent 50-lbf(220-N)force and an additionalweight exerting a 50-lbf making a total of 100-lbf(445-N).Thetwo glass plates shall be kept sharp by removing from themachine and grinding them face-to-face with No.303 opticalemery or equivalent,and water.5.6 SpatulaA flexible spatula having a chromium-platedor plastic blade 75 to 150 mm(3 to 6 in.)long.5.7 Panels of bright tin,glass,or white-lacquered card-board.5.8 ScraperAFrench scraper or stiff scraping knife havinga blade that is about 75 to 100 mm(3 or 4 in.)wide with astraight edge.6.Materials6.1 Tinting MaterialUltramarine blue conforming toSpecification D262 or a grade agreed upon by the purchaserand the seller.6.2 OilRefined linseed oil with an acid number of ap-proximatel