1、Designation:D27902(Reapproved 2012)Standard Test Methods forBleeding of Pigments1This standard is issued under the fixed designation D279;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 parenthes
2、es 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 Department of Defense.1.Scope1.1 These test methods cover procedures for determiningthe bleeding characteristi
3、cs of dry pigments by direct solventextraction of the pigment and by overstriping a film with awhite coating and observing for the color migration from thebase coat containing the pigment.1.2 The values stated in SI units are to be regarded as thestandard.The values given in parentheses are for info
4、rmationonly.1.3 This standard does not purport to address all of thesafety problems,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.Refe
5、renced Documents2.1 ASTM Standards:2D2244 Practice for Calculation of Color Tolerances andColor Differences from Instrumentally Measured ColorCoordinatesD2616 Test Method for Evaluation of Visual Color Differ-ence With a Gray Scale3.Summary of Test Methods3.1 Test Method AThe pigment is shaken with
6、toluene,filtered,and the filtrate observed for color.3.2 Test Method BA coating using the pigment under testis prepared and applied to one half of a panel.A white finish isapplied over the dried colored coating and extended to theuncoated portion of the panel.The dried overstripe coating isexamined
7、for color migration from the base coat.4.Significance and Use4.1 Test MethodAdetermines the amount of color producedwhen the pigment is in direct contact with a selected solventsuch as toluene.It is useful as a rapid,easily conducted test ofthe general bleeding characteristics of pigments.4.2 Test M
8、ethod B determines the amount of color migra-tion into a white film applied over a base coat containing thepigment.It may give a more practical evaluation of whether apigment will meet specific requirements for bleed resistance.4.3 Both Test Method A and Test Method B measure theextent of bleed.TEST
9、 METHOD A,DIRECT SOLVENT CONTACTWITH PIGMENT5.Procedure5.1 Place 0.50 g of pigment(Note 1)in a test tube or vialand add 20-mL of reagent grade toluene(Note 2).Close witha stopper,shake well for 10 s,and let stand 15 min.Repeat the10-s shake and let stand 45 min.NOTE1Additional amounts of pigment may
10、 be used by prioragreement for denser inorganic pigments.A maximum of 1.5 g isrecommended for even the dense lead chromate pigments.NOTE2Other solvents may be used,by mutual agreement between theparties involved,in place of toluene in a specific pigment bleed evaluation.5.2 Filter through a glass fu
11、nnel using double filter paperthat has first been wet with toluene and collect approximately10 mL of filtrate in a 23 mm outer diameter flat bottom vial.Ifthe filtrate is cloudy,refilter to get a clear filtrate.NOTE3In the case of colloidal particles,it may be necessary tocentrifuge the filtrate.5.3
12、 Hold the vial containing the filtrate above a whitebackground and look down through the filtrate for colorationcaused by pigment bleed.Describe the degree or severity ofbleed according to the following terminology or use the GrayScale(Test Method D2616):5.3.1 NoneNo perceptible color(that is,no ble
13、ed).5.3.2 SlightA faint but distinct coloration.5.3.3 ModerateA pronounced but not severe coloration.5.3.4 SevereAn intense coloration.1These test methods are under the jurisdiction of ASTM Committee D01 onPaint and Related Coatings,Materials,and Applications and are the directresponsibility of Subc
14、ommittee D01.31 on Pigment Specifications.Current edition approved Nov.1,2012.Published November 2012.Originallyapproved in 1928.Last previous edition approved in 2007 as D279 02(2007).DOI:10.1520/D0279-02R12.2For referenced ASTM standards,visit the ASTM website,www.astm.org,orcontact ASTM Customer
15、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 TEST METHOD B,WHITE OVERSTRIPE OF APIGMENTED FI
16、LM6.Procedure6.1 Prepare a coating of agreed upon composition,using thepigment under test,and prepare a film of this coating by anymethod that will give a smooth and uniform film of normalcoating thickness(that is,in the range from 1 to 3 mils)(25 to75 m)leaving a portion of the substrate uncoated.Cure thefilm under conditions appropriate to the end use.For air dryfilms,dry at room temperature,approximately 25C(77F)fora minimum of 24 h.6.2 Pretreatments of the colored coating,such as sanding ors
