1、Designation: D 2371 85 (Reapproved 2005)Standard Test Method forPigment Content of Solvent-Reducible Paints1This standard is issued under the fixed designation D 2371; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of las
2、t revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon (e) 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 This test method covers the procedure f
3、or the quantita-tive separation of the vehicle from the pigment in solvent-reducible coatings.1.2 This test method has been proven to be applicable to thefollowing types of paints: white linseed oil outside house paint,white soya and phthalic alkyd enamel, white linseed o-phthalicalkyd enamel, red l
4、ead primer, zinc chromate primer, flat whiteinside enamel, white epoxy enamel, white vinyl toluenemodified alkyd, and white amino modified baking enamel. It isconsidered to be applicable to most solvent-reducible paints.1.3 The values stated in SI units are to be regarded as thestandard. The values
5、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 regula
6、tory limitations prior to use. Specific hazardstatements are given in Section 6.2. Referenced Documents2.1 ASTM Standards:2D 2698 Test Method for Determination of the PigmentContent of Solvent-Reducible Paints by High-Speed Cen-trifuging3. Significance and Use3.1 This test method is suitable for set
7、ting specifications forthe pigment content of solvent-reducible paints as well as formonitoring manufacturing quality control.3.2 This test method provides the isolated pigment fractionfrom solvent-reducible paints that may be used for pigmentanalysis.4. Apparatus4.1 Centrifuge, explosion-proof, cap
8、able of developing1000 to 2000 g.NOTE 1The centrifuge should be equipped with a suitable head totake the proper size trunnion cups necessary for use of the 90-mL tubes or120-mL (4-oz) bottles. A two, four, or six-place head can be used with thebottles and an eight-place head can be used with the tub
9、es.4.2 Centrifuge Tube, 90-mL, heavy-walled. In place of the90-mL centrifuge tube a 120-mL (4-oz) screw cap bottle withvinyl-lined screw cap may be used.34.3 Laboratory Oven, vented and capable of maintaining atemperature of 105 6 2C.4.4 Syringe, 5-mL.4.5 Water Bath.5. Solvents5.1 Ethyl Ether or Pet
10、roleum Ether: (WarningSee 6.1).5.2 Extraction MixtureMix 10 volumes of ethyl ether, 6volumes of benzene or toluene, 4 volumes of methyl alcohol,and 1 volume of acetone (WarningSee 6.2, 6.3, and 6.4).6. Hazards6.1 Ethyl Ether and Petroleum Ether Flammable. Vaporis harmful. May be fatal if inhaled or
11、swallowed. Use only withadequate ventilation. Avoid prolonged contact with skin. Avoidcontact with flame, hot surface, or sparks. Do not get in eyes,on skin, or on clothing. Refer to suppliers Material SafetyData Sheet.6.2 AcetoneFlammable. Vapor is harmful. May be fatal ifinhaled or swallowed. Use
12、only with adequate ventilation.Avoid prolonged contact with skin. Avoid contact with flame,hot surface, or sparks. Do not get in eyes, on skin, or onclothing. Refer to suppliers Material Safety Data Sheet.6.3 Methyl AlcoholFlammable. May be fatal or causeblindness if swallowed. Cannot be made nonpoi
13、sonous. Harm-ful if inhaled. Keep away from heat, sparks, or open flame.1This test method is under the jurisdiction of ASTM Committee D01 on Paintand Related Coatings, Materials, and Applications and is the direct responsibility ofSubcommittee D01.21 on Chemical Analysis of Paints and Paint Material
14、s.Current edition approved Jan. 1, 2005. Published February 2005. Originallyapproved in 1965. Last previous edition approved in 1999 as D 2371 85 (1999).2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMSt
15、andards volume information, refer to the standards Document Summary page onthe ASTM website.3The sole source of supply of bottles and caps, Cat. No. S9185C, 4-oz bottle,known to the committee at this time is Sargent Welch Scientific, 7300 N. LinderAve., Skokie, IL 60076. If you are aware of alternat
16、ive suppliers, please provide thisinformation to ASTM International Headquarters. Your comments will receivecareful consideration at a meeting of the responsible technical committee1, whichyou may attend.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2
17、959, United States.Avoid breathing vapor. Use only with adequate ventilation.Refer to suppliers Material Safety Data Sheet.6.4 Benzene has been declared carcinogenic.6.4.1 Benzene and TolueneFlammable. Vapors and liquidare harmful and may be fatal if swallowed. Keep away fromheat, sparks, or open fl
18、ame. Keep in a well-closed container.Avoid breathing vapor. Avoid contact with eyes, skin, orclothing. Refer to suppliers Material Safety Data Sheet.7. Procedure7.1 Mix the sample until it is homogeneous, preferably on amechanical shaker.7.2 Weigh to 1 mg from a syringe, 5 to 10 g of sample intoa ta
19、red 90-mL centrifuge tube with a screw-type glass stirringrod (the rod is tared with the centrifuge tube), or a glass bottleas described in 4.2. The weight of the specimen is the weightof syringe and paint minus the weight of the syringe aftertransferring the specimen to the tube or bottle.7.3 Add 6
20、0 mL of extraction mixture (5.2) and stir well withthe glass, screw-type stirring rod, preferably using a powerstirrer. Wash the rod clean with a stream of extraction mixtureinto the tube, and reserve the rod. If the glass bottle is used,mixing may be accomplished by hand, shaking vigorously, orby u
21、se of a mechanical shaker.7.4 Centrifuge at 1000 to 2000 g (Note 2) until the pigmentis clearly separated. A faster speed may cause the pigment topack too hard for future mixing. (See Test Method D 2698.)NOTE 2Calculate the gravity developed by the centrifuge as follows:g 5 1.118 3 10263 r 3 n2(1)wh
22、ere:r = rotating radius, mm, andn = rotating speed, r/min.7.5 Discard the upper layer by decantation.7.6 Repeat the extraction twice as described in 7.3, 7.4, and7.5, making certain that the settled pigment is sufficientlystirred or shaken so that no lumps can be seen sticking to theside of the cent
23、rifuge tube or bottle and all pigment can easilybe washed from the stirring rod into the tube. It may benecessary to break up the pigment cake before stirring. Thebottle and contents may be mixed by tapping at an angle on acloth pad on a bench top to break up the pigment cake and thenshaking vigorou
24、sly to complete the pigment dispersion in theextraction mixture.7.7 Make a fourth extraction using ethyl ether or petroleumether following the same precautions noted in 7.6. Decant theupper layer. Drive off the ether by heating (gently at first toavoid spattering) on a steam bath in a hood away from
25、 openflames or sparks. The pigment should be broken up by tappingthe tube or bottle on a cloth pad on a bench top. Dry the tubeor the bottle at 105 6 2C for 2 h.7.8 Cool and weigh the tube (including stirring rod) orbottle, plus pigment.8. Calculation8.1 Calculate the percent of pigment, P, as follo
26、ws:P 5 W12 W2!/S 3 100 (2)where:W1= weight of the tube (including stirring rod) pluspigment, g,W2= weight of the tube (including stirring rod), g, andS = weight of paint sample used, g.NOTE 3All pigment obtained using this test method has minuteamounts of vehicle adsorbed on the pigment. However, th
27、is will notsignificantly affect the precision of this test method.9. Precision9.1 Data are not available to determine the precision of thistest method. There are no plans at present to obtain such data.This test method has been in use for several years and isconsidered acceptable.10. Keywords10.1 hi
28、gh speed centrifuging; pigment content; pigmentseparation; solvent-reducible paintASTM International takes no position respecting the validity of any patent rights asserted in connection with any item mentionedin this standard. Users of this standard are expressly advised that determination of the v
29、alidity of any such patent rights, and the riskof infringement of such rights, are entirely their own responsibility.This standard is subject to revision at any time by the responsible technical committee and must be reviewed every five years andif not revised, either reapproved or withdrawn. Your c
30、omments are invited either for revision of this standard or for additional standardsand should be addressed to ASTM International Headquarters. Your comments will receive careful consideration at a meeting of theresponsible technical committee, which you may attend. If you feel that your comments ha
31、ve not received a fair hearing you shouldmake your views known to the ASTM Committee on Standards, at the address shown below.This standard is copyrighted by ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959,United States. Individual reprints (single or multiple copies) of this standard may be obtained by contacting ASTM at the aboveaddress or at 610-832-9585 (phone), 610-832-9555 (fax), or serviceastm.org (e-mail); or through the ASTM website(www.astm.org).D 2371 85 (2005)2
