1、Designation: D281 12Standard 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 of last revision. A number
2、 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 Department of Defense.1. Scope*1.1 This test method covers the determination of the oilabsorpt
3、ion of pigments by the spatula rub-out technique.1.2 The values stated in SI units are to be regarded asstandard. The values given in parentheses are for informationonly.1.3 This standard does not purport to address all of thesafety concerns, if any, associated with its use. It is theresponsibility
4、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:2D1483 Test Method for Oil Absorption of Pigments byGardner-Coleman Method3. Summary of Test Method3.1
5、A stiff, putty-like paste is formed by the dropwiseaddition of linseed oil to pigment that is being thoroughlyrubbed with a spatula. The amount of oil required to producethe end point is used to calculate an oil absorption value.4. Significance and Use4.1 The oil absorption value obtained by this te
6、st methodgives information about the vehicle demand of the pigmentwhen it is used in a pigment paste. Oil absorption values can beused to characterize pigments or batches of a given pigment.4.2 This test method differs from Test Method D1483 in thatD1483 involves only a gentle stirring and folding o
7、f thepigment, whereas this test method requires a thorough rubbingaction. Because the end points are different, the values obtainedfrom the two test methods generally differ.5. Apparatus and Materials5.1 Balance, capable of weighing to 0.001 g.5.2 Dropping Bottle, fitted with ground-in pipet and rub
8、berbulb or buret, graduated in 0.1-mL divisions.5.3 Smooth Glass Rub-up Plate or Marble Slab (glassshould have a surface similar to Hoover Muller Plates).5.4 Spatula, sharp-edged, steel, having a blade of 15 or 20mm by 100 mm (12 or34 by 4 in.).5.5 Oil, linseed, raw, conforming to the following spec
9、ifi-cation:Specific Gravity 0.9260.931Boiling Point 149CAcid Number 3 6 1Saponification Value 185196Iodine Value 170 minimumGardner Color 13 maximum5.5.1 Linseed oil used in comparative tests must have thesame acid value. Other liquids, such as refined oil, may be usedby mutual agreement.6. Procedur
10、e6.1 Procedure A (Weighing Bottle)Weigh exactly 1 g, orany multiple thereof (Note 1), of the thoroughly mixed and airdried pigment and place upon a glass plate or marble slab.Weigh to 0.01 g a dropping bottle containing raw linseed oilalong with the pipet and rubber bulb. Add the linseed oilgraduall
11、y, drop by drop (by means of the pipet), to the pigment.After the addition of each drop, thoroughly incorporate the oilby rubbing up with the spatula. The test is complete whenexactly enough oil has been incorporated with the pigment toproduce a very stiff, putty-like paste, that does not break orse
12、parate. Weigh the bottle and oil to 0.01 g and determine bydifference the weight of oil used. The time that it took to runthe test (in minutes) should be noted. Subsequent tests on thesame kind of pigment should be performed in approximatelythe same period of time. Any device capable of measuringmin
13、utes may be used.1This test method is under the jurisdiction of ASTM Committee D01 on Paintand Related Coatings, Materials, and Applications and is the direct responsibility ofSubcommittee D01.24 on Physical Properties of Liquid Paints pigments (general properties); spatularub-out testSUMMARY OF CHA
14、NGESCommittee 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 April 15, 2012.)(1) D234, Specification for Raw Linseed Oil has been with-drawn. Therefore, the properties of the oil are being
15、listed insection 5.5 in this standard. Also, there have been requests toinclude a mention of the time taken for the test. Therefore, asentence indicating the need to note the time taken for the testand that subsequent tests on the same kind of pigment shouldbe performed in approximately the same per
16、iod of time hasbeen added to the procedure.ASTM 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 validity of any such patent rights, and
17、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 comments are invited either for revision
18、 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 have not received a fair hearing you shou
19、ldmake 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). Permission rights to photocopy the standard may also be secured from the ASTM website (www.astm.org/COPYRIGHT/).D281 122
