1、Designation: D281 12D281 12 (Reapproved 2016)Standard Test Method forOil Absorption of Pigments by Spatula Rub-out1This standard is issued under the fixed designation D281; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year o
2、f 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. Scope*Scope1.1 This test method covers
3、the determination of the oil absorption of pigments by the spatula rub-out technique.1.2 The values stated in SI units are to be regarded as standard. The values given in parentheses are for information only.1.3 This standard does not purport to address all of the safety concerns, if any, associated
4、 with its use. It is the responsibilityof the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatorylimitations prior to use.2. Referenced Documents2.1 ASTM Standards:2D1483 Test Method for Oil Absorption of Pigments by Gardner-Colema
5、n Method3. Summary of Test Method3.1 A stiff, putty-like paste is formed by the dropwise addition of linseed oil to pigment that is being thoroughly rubbed witha spatula. The amount of oil required to produce the end point is used to calculate an oil absorption value.4. Significance and Use4.1 The o
6、il absorption value obtained by this test method gives information about the vehicle demand of the pigment when itis used in a pigment paste. Oil absorption values can be used to characterize pigments or batches of a given pigment.4.2 This test method differs from Test Method D1483 in that D1483 inv
7、olves only a gentle stirring and folding of the pigment,whereas this test method requires a thorough rubbing action. Because the end points are different, the values obtained from the twotest methods generally differ.5. Apparatus and Materials5.1 Balance, capable of weighing to 0.001 g.5.2 Dropping
8、Bottle, fitted with ground-in pipet and rubber bulb or buret, graduated in 0.1-mL divisions.5.3 Smooth Glass Rub-up Plate or Marble Slab (glass should have a surface similar to Hoover Muller Plates).5.4 Spatula, sharp-edged, steel, having a blade of 15 or 20 mm by 100 mm (12 or 34 by 4 in.).5.5 Oil,
9、 linseed, raw, conforming to the following specification:Specific GravityBoiling PointAcid NumberSaponification ValueIodine ValueGardner Color1 This test method is under the jurisdiction of ASTM Committee D01 on Paint and Related Coatings, Materials, and Applications and is the direct responsibility
10、 ofSubcommittee D01.24 on Physical Properties of Liquid Paints pigments (general properties); spatula rub-out testSUMMARY OF CHANGESCommittee D01 has identified the location of selected changes to this standard since the last issue(D281 - 95(2007) that may impact the use of this standard. (Approved
11、April 15, 2012.)(1) D234, Specification for Raw Linseed Oil has been withdrawn. Therefore, the properties of the oil are being listed in section5.5 in this standard. Also, there have been requests to include a mention of the time taken for the test. Therefore, a sentenceindicating the need to note t
12、he time taken for the test and that subsequent tests on the same kind of pigment should be performedin approximately the same period of time has been added to the procedure.ASTM International takes no position respecting the validity of any patent rights asserted in connection with any item mentione
13、din this standard. Users of this standard are expressly advised that determination of the validity 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
14、must be reviewed every five years andif not revised, either reapproved or withdrawn.Your comments 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 t
15、heresponsible technical committee, which you may attend. If you feel that your comments have 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 C7
16、00, 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). Permission rights to photocopy the standard may also be secured from the Copyright Clearance Center, 222Rosewood Drive, Danvers, MA 01923, Tel: (978) 646-2600; http:/ 12 (2016)3
