1、Designation: D387 00 (Reapproved 2017)Standard Test Method forColor and Strength of Chromatic Pigments with aMechanical Muller1This standard is issued under the fixed designation D387; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision
2、, 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.This standard has been approved for use by agencies of the U.S. Department of Defense.1. Scope1.1 This test method i
3、s intended to be used to compare thecolor and strength of a pigment under test with a referencestandard of the same type and grade.1.2 This test method does not apply to white pigments.NOTE 1Test Method D3022 is similar to this test method, but itutilizes a miniature sandmill rather than a mechanica
4、l muller, to dispersethe chromatic pigment.NOTE 2Test Method D332 and Test Method D2745 are similar to thistest method, but they are intended for use with white pigments, rather thanchromatic pigments.1.3 The values stated in SI units are the preferred unit ofmeasurement. The values given in parenth
5、eses are for infor-mation only.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 limitatio
6、ns prior to use. Specific hazardstatements are given in Section 8.2. Referenced Documents2.1 ASTM Standards:2D332 Test Method for Relative Tinting Strength of WhitePigments by Visual ObservationD1729 Practice for Visual Appraisal of Colors and ColorDifferences of Diffusely-Illuminated Opaque Materia
7、lsD2244 Practice for Calculation of Color Tolerances andColor Differences from Instrumentally Measured ColorCoordinatesD2745 Test Method for Relative Tinting Strength of WhitePigments by Reflectance MeasurementsD3022 Test Method for Color and Strength of Color Pig-ments by Use of a Miniature Sandmil
8、lD3964 Practice for Selection of Coating Specimens forAppearance MeasurementsD4838 Test Method for Determining the Relative TintingStrength of Chromatic PaintsE284 Terminology of Appearance3. Terminology3.1 Definitions of appearance terms used in this test methodmay be found in Terminology E284.4. S
9、ummary of Test Method4.1 Pigments are dispersed in a suitable vehicle with amechanical muller. Test and standard pigments are treatedidentically. Opaque drawdowns are made from the dispersionsand compared, either visually or instrumentally, for color andstrength differences.5. Significance and Use5.
10、1 Color and tinting strength are the most important prop-erties of a color pigment. This test method provides a means oftesting these properties for quality control.5.2 This test method is intended as a referee method so thatsuch matters as the vehicle for preparing the dispersions andthe white for
11、making tints have been suggested. However,other vehicles and whites may be suitable for quality controlpurposes, and changes in this test method are allowed byagreement between the parties to a test.5.3 It is assumed that the most exact comparison of masscolor and tinting strength occurs when the pi
12、gment is com-pletely dispersed. By following the procedure described inAnnexA1, the conditions for achieving the maximum practicaldegree of dispersion with a mechanical muller may be deter-mined. Color and strength tests should be carried out underthese conditions.5.4 The results obtained with a mec
13、hanical muller do notnecessarily correlate directly with an industrial situation wheredifferent dispersing conditions exist. However, dispersion with1This test method is under the jurisdiction of ASTM Committee D01 on Paintand Related Coatings, Materials, and Applications and is the direct responsib
14、ility ofSubcommittee D01.26 on Optical Properties.Current edition approved Feb. 1, 2017. Published March 2017. Originallyapproved in 1934. Last previous edition approved in 2008 as D387 00 (2008).DOI: 10.1520/D0387-00R17.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact
15、 ASTM Customer 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 StatesThis international standard
16、 was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for theDevelopment of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.1a mechani
17、cal muller is a quick and inexpensive way of testingthe color and strength of a pigment for routine quality control.6. Apparatus6.1 Balances(1) A balance sensitive to 10 mg and (2)ananalytical balance sensitive to 1.0 mg.6.2 Muller, Mechanical, equipped with ground-glass platesto which a variable bu
18、t known force may be added in 220-N(50-lbf) increments. The driven glass plate shall have a speedof rotation of between 70 and 120 r/min and the apparatus shallhave an arrangement for pre-setting the number of revolutionsin multiples of 50.6.3 Rubbing SurfacesThe rubbing surfaces of the groundglass
19、plates shall be kept sharp by removing them from themuller and grinding them face-to-face with No. 303 opticalemery, or its equivalent, and water.6.4 Small Glass Slab or other nonabsorbent material, suit-able for weighing and mixing pigment pastes.6.5 SpatulaAflexible spatula having a 75 to 150-mm (
20、3 to6-in.) blade.6.6 Paper Charts, white with a black band and a surfaceimpervious to paint liquids.6.7 Film Applicator, at least 75 mm (3 in.) wide with aclearance of 100 m (4 mils) to produce wet films about 50 m(2 mils) thick.6.8 Color-Measuring Instrument, meeting the requirementsof Practice D22
21、44.7. Materials7.1 Reference StandardA standard pigment of the sametype and grade as the pigment to be tested, as agreed uponbetween the purchaser and the seller.7.2 VehicleA solvent-free vehicle, such as No. 1 litho-graphic varnish, with 0.8 % each of cobalt and manganesedriers (6 % types).7.3 Whit
22、e Tinting PasteA white paint compatible with thedispersion vehicle, such as 57 parts of rutile titanium dioxidedispersed in 43 parts of the vehicle described in 7.2.NOTE 3Because the choice of vehicle and white tinting pigment mayaffect the results, they should be agreed upon between the purchaser a
23、ndthe seller.8. Hazards8.1 Some pigments are potentially toxic and thereforeshould be handled with care. Obtain specific precautions fromthe manufacturer or supplier.8.2 Many solvents and paint vehicles present explosion, fire,and toxicity hazards, so they should accordingly be handledwith care. Aga
24、in, obtain specific precautions from the manu-facturer or supplier.9. Dispersing Conditions9.1 The conditions for dispersing the pigment on the me-chanical muller should be such that the maximum tintingstrength is developed. For each pigment and each dispersingvehicle the development of tinting stre
25、ngth by the mechanicalmuller is influenced by the force applied, the number ofrevolutions, the mass of the pigment, and the mass of thevehicle. The conditions for obtaining the maximum tintingstrength with the mechanical muller can be determined byfollowing the procedure in Annex A1.9.2 If these con
26、ditions are known for a particular pigmentwith a particular vehicle, or if the purchaser and seller agreeupon a particular set of conditions, there is no need to carry outthe procedure in Annex A1.10. Dispersion Procedure10.1 Decide, by agreement or by experimentation, as dis-cussed in Section 9, th
27、e following dispersing conditions:10.1.1 Force applied to the muller plates;10.1.2 Number of revolutions;10.1.3 Mass of the pigment; and10.1.4 Mass of the vehicle.10.2 Applying these decisions, prepare a dispersion of thereference standard pigment. Weigh onto a glass slab to within2 mg, the appropri
28、ate quantities of the standard pigment andthe dispersing vehicle. Mix the pigment and vehicle togetherthoroughly with the spatula and transfer the mixture to thelower plate of the muller. Spread the mixture in a pathapproximately 100 mm wide and halfway between the centerand rim of the lower plate,
29、and clean the spatula as much aspossible by wiping it on the upper plate of the muller. Close theplates and carry out the mulling stages of 50 revolutions; aftereach stage collect the paste from both plates with the spatulaand spread it around the 100-mm path on the lower plate,wiping the spatula on
30、 the upper plate as before. When themulling has been carried out for the prescribed number ofrevolutions, collect the paste and store it. Clean the glass slab,the muller plates, and the spatula, and repeat the procedurewith exactly the same quantities of the test sample and vehicle.Collect the paste
31、 from this sample and store it. Clean the glassslab, the muller plates, and the spatula.NOTE 4The most common sources of error in this procedure areinaccurate weighing, incomplete transfer of the pigment and vehiclemixture, and contamination of the plates by previous samples.11. Masstone Color Proce
32、dure11.1 Draw down a portion of the test and standard pastes injuxtaposition on a paper chart over a vacuum-drawdown plateor other suitable plane surface with the film applicator. Makesure that the coating is opaque.11.2 Immediately compare the colors visually while stillwet, using Practice D1729, a
33、nd record the results. Set thedrawdowns aside in a dust-free area to dry. When dry, repeatthe visual color difference evaluation and record the results.See Practice D3964.11.3 If desired, evaluate the color difference instrumentallyusing Practice D2244, and report the color difference in unitsas agr
34、eed upon between the purchaser and seller.NOTE 5Wet color difference evaluations may not agree with dry colordifference evaluations because of such phenomena as flooding andflocculation. In the case of a difference between the wet and dryD387 00 (2017)2evaluations, the purchaser and the seller shoul
35、d agree upon whichcondition is the standard.NOTE 6Color difference measurements of wet paints may require aspecial adapter to protect the instrument from fouling. Because colordifference-measuring instruments differ widely in their design, the usermay have to develop his own adapter.12. Tint Color P
36、rocedure12.1 Determine by calculation the amount of white pigmentpaste that must be added to 0.5 g of the color pigment paste sothat the mixture contains 1 part of dry color pigment to 10 partsof dry white pigment. For stronger or weaker pigments thisratio may be adjusted accordingly, for example, 1
37、:20 or 1:5,respectively.12.2 Weigh 500 6 2 mg of the standard color pigment pasteonto a glass slab. Then weigh the amount of white pigmentpaste determined in 12.1, and place it next to the color pigmentpaste on the glass slab. Thoroughly mix the two pastes togetherwith the spatula until a uniform co
38、lor is observed.12.3 Prepare a tint mixture of the test color pigment pasteand the white pigment paste on a separate glass slab by theprocedure described in 12.2.12.4 Draw a portion of the test and standard tint pastesdown in juxtaposition on a paper chart as in 11.1. Evaluate thecolor difference vi
39、sually as in 11.2 and, if desired, instrumen-tally as in 11.3. Clean the spatula blade and glass slabs.13. Calculation of Tinting Strength13.1 If the colors of the test tint paste and the standard tintpaste are visually the same, the tinting strength of the testpigment is equal to that of the standa
40、rd pigment, and therelative tinting strength of the test pigment is 100 %. However,if the test and standard colors are not the same, the differencemay be due to either tinting strength or hue (shade).13.2 To determine the relative tinting strength of the testpigment, repeat the operations of Section
41、 12, but this time usean amount of the test pigment paste that is estimated to give theclosest color match to the standard pigment paste. Repeat thisprocedure until satisfied that the closest color match has beenobtained. At this point any residual color difference betweenthe test and the standard p
42、igments is attributed to a shadedifference, rather than a strength difference. Note and recordthis shade difference.13.3 Calculate the relative tinting strength of the test pig-ment by dividing the mass of the standard paste by the mass ofthe test paste used to obtain the closest color match; multip
43、lyby 100 to express the result in percent.13.4 If desired, the relative tinting strength of the samplepigment can be calculated from instrumental measurementsusing the following equation:TS 5 1 2 R!2/2R#u/1 2 R!2/2R#sT!where:TS = tinting strength of test pigment,R= measured reflectant factor (as a d
44、ecimal),T = assigned tinting strength of standard, usually 100 %,and subscripts “u” and “s” refer to the test and standardpigments, respectively.13.4.1 To determine R, follow instructions in the firstparagraph of the Summary section and the second paragraph ofthe Specimen Preparation section of Test
45、 Method D4838.14. Report14.1 Report the following information:14.1.1 Type and identification of the test pigment, referencestandard pigment, white tinting pigment, and dispersing ve-hicle.14.1.2 Mass ratio of pigment to vehicle, and for tints, massratio of color pigment mass to white pigment.14.1.3
46、Manufacturer and model number of the mechanicalmuller employed.14.1.4 Total force applied to the muller plates and totalnumber of revolutions.14.1.5 Results of the visual evaluation of the color differ-ence (masstone and tint) in accordance with Practice D1729.14.1.6 If an instrument was used to eva
47、luate the colordifference, the results of the instrumental evaluation in accor-dance with Practice D2244.14.1.7 Relative tinting strength and method by which it wasdetermined (visual or instrumental). Also, for the instrumentalmethod, the parameter used as the measure of Rin.14.1.8 Any deviation, by
48、 agreement or otherwise, from thetest procedure just described.15. Precision15.1 PrecisionThe precision of this test method dependson several factors such as the type of pigment, the level oftinting, and the magnitude and direction of the color difference.This point is illustrated by the results in
49、Table 1, whichcontains the between-laboratories standard deviations obtainedin an interlaboratory study involving five different laboratoriesand four different pigments. The dispersing conditions used toobtain these results are listed in Table 2.15.2 Table 3 lists the maximum acceptable differences,calculated at the 95 % confidence level from the results inTable 1.D387 00 (2017)316. Keywords16.1 chromatic pigment; color; mullerANNEX(Mandatory Information)A1. DISPERSING CONDITIONS FOR MAXIMUM TINTING STRENGTHA1.1 The following describes a test method for d
