1、Designation: D 387 00Standard Test Method forColor and Strength of Chromatic Pigments with aMechanical Muller1This standard is issued under the fixed designation D 387; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of la
2、st 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 is intended to be use
3、d 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 D 3022 is similar to this test method, but itutilizes a miniature sandmill rather than a mechanical muller, to disper
4、sethe chromatic pigment.NOTE 2Test Method D 332 and Test Method D 2745 are similar tothis test method, but they are intended for use with white pigments, ratherthan cohromatic pigments.1.3 The values stated in SI units are the preferred unit ofmeasurement. The values given in parentheses are for inf
5、or-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 limitations prior to use.
6、 Specific hazardstatements are given in Section 8.2. Referenced Documents2.1 ASTM Standards:D 332 Test Method for Relative Tinting Strength of WhitePigments by Visual Observation2D 1729 Practice for Visual Evaluation of Color Differencesof Opaque Materials2D 2244 Test Method for Calculation of Color
7、 Differencesfrom Instrumentally Measured Color Coordinates2D 2745 Test Method for Relative Tinting Strength of WhitePigments by Reflective Measurements2D 3022 Test Method for Color and Strength of ColorPigments by Use of a Miniature Sandmill2D 3964 Practice for Selection of Coating Specimens forAppe
8、arance Measurements2D 4838 Test Method for Determining the Relative TintingStrength of Chromatic Paints3E 284 Terminology of Appearance23. Terminology3.1 Definitions of appearance terms used in this test methodmay be found in Terminology E 284.4. Summary of Test Method4.1 Pigments are dispersed in a
9、 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 Use5.1 Color and tinting strength are the most important
10、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 making tints have been suggested. However,other vehi
11、cles 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 pigment is com-pletely dispersed. By following the pro
12、cedure described inAnnex A1, 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 mechanical muller do notnecessarily correlate directly
13、 with an industrial situation wheredifferent dispersing conditions exist. However, dispersion witha mechanical 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
14、balance sensitive to 1.0 mg.6.2 Muller, Mechanical, equipped with ground-glass plates1This test method is under the jurisdiction of ASTM Committee D-1 on Paintand Related Coatings, Materials, and Applications and is the direct responsibility ofSubcommittee D01.26 on Optical Properties.Current editio
15、n approved June 00, 2000. Published August 2000. Originallypublished as D 387 34 T. Last previous edition D 387 86 (1994).2Annual Book of ASTM Standards, Vol 06.01.3Annual Book of ASTM Standards, Vol 06.02.1Copyright ASTM, 100 Barr Harbor Drive, West Conshohocken, PA 19428-2959, United States.to whi
16、ch a variable but 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
17、the groundglass 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,suitable for weighing and mixing pigment pastes.6.5 SpatulaA flexible spatula having a
18、 75 to 150-mm (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 requirements
19、of Test Method D 2244.7. 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 (
20、6 % types).7.3 White 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 betw
21、een the purchaser andthe seller.8. Hazards8.1 Some pigments may be 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, and they should accordingly b
22、e handledwith care. Again, 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 deve
23、lopment of tinting strength 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 An
24、nex A1.9.2 If these conditions 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-
25、cussed in Section 9, the 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 w
26、ithin2 mg, the appropriate 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 r
27、im of the lower plate, 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 plat
28、e,wiping the spatula on 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 ve
29、hicle.Collect the paste 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.1
30、1. Masstone Color Procedure11.1 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,
31、using Practice D 1729, and 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 D 3964.11.3 If desired, evaluate the color difference instrumentallyusing Test Method D 2244, and report the co
32、lor difference inunits as agreed 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 dryevaluations, the purchaser and th
33、e seller should 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
34、. Tint Color Procedure12.1 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 thisD 3872ratio may be adjusted accordi
35、ngly, for example, 1:20 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 spatul
36、a until a uniform color 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 th
37、ecolor difference visually 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 t
38、o that of the standard 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 o
39、perations of Section 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 tes
40、t and the standard pigments 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
41、 color match; multiplyby 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 5 tinting strength of test pigment,R5 measured refl
42、ectant factor (as a decimal),T 5 assigned tinting strength of standard, usually 100 %,and subscripts “u” and “s” refer to the test andstandard pigments, respectively.13.4.1 To determine R, follow instructions in the firstparagraph of the Summary section and the second paragraph ofthe Specimen Prepar
43、ation section of Test Method D 4838.14. 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
44、 white pigment.14.1.3 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 D 1729.14.1.6 If an ins
45、trument was used to evaluate the colordifference, the results of the instrumental evaluation in accor-dance with Test Method D 2244.14.1.7 Relative tinting strength and method by which it wasdetermined (visual or instrumental). Also, for the instrumentalmethod, the parameter used as the measure of R
46、in.14.1.8 Any deviation, by 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 ill
47、ustrated by the results in 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 maxi
48、mum acceptable differences,calculated at the 95 % confidence level from the results inTable 1.D 387316. Keywords16.1 chromatic pigment; color; mullerANNEX(Mandatory Information)A1. DISPERSING CONDITIONS FOR MAXIMUM TINTING STRENGTHA1.1 The following describes a test method for determiningthe conditi
49、ons for achieving the maximum level of tintingstrength with the mechanical muller.A1.2 Determine the appropriate ratio of color pigment todispersing vehicle by performing the following operations:Tare off the weight of a glass slab on a balance. Weigh 1.00 60.01 g of the standard pigment on to the glass slab. Adddispersing vehicle to the pigment in small amounts and mixthem together with the spatula. Keep adding the vehicle andmixing the paste until the pigment is completely wetted and aworkable paste is obtained. At this point the consistency of thepaste shou
