1、Designation: D 4890 06Standard Test Methods forPolyurethane Raw Materials: Determination of Gardner andAPHA Color of Polyols1This standard is issued under the fixed designation D 4890; 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 (e) indicates an editorial change since the last revision or reapproval.1. Scope*1.1 These test methods measure visually the color of clearpolyester and polyether liquids. They apply only
3、 to materialswhose colors have light-absorption characteristics similar tothose of the standards. An alternative method is Test MethodD 1209 (see Note 1).1.2 This standard does not purport to address all of thesafety concerns, if any, associated with its use. It is theresponsibility of the user of t
4、his standard to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.NOTE 1Although Test Method A of these test methods and ISO 4630-1:2004 differ in some details, data obtained using either are technicallyequivalent. Although Tes
5、t Method B of these test methods and ISO 6271-1981 differ in some details, data obtained using either are technicallyequivalent.2. Referenced Documents2.1 ASTM Standards:2D 883 Terminology Relating to PlasticsD 1193 Specification for Reagent WaterD 1209 Test Method for Color of Clear Liquids (Platin
6、um-Cobalt Scale)D 5386 Test Method for Color of Liquids Using TristimulusColorimetryE 308 Practice for Computing the Colors of Objects byUsing the CIE SystemE 1164 Practice for Obtaining Spectrometric Data forObject-Color Evaluation2.2 ISO Standards:3ISO 4630-1:2004 Estimation of Colour by the Gardn
7、er Co-lour ScalePart 1: Visual MethodISO 4630-2:2004 Clear LiquidsEstimation of Colour bythe Gardner Colour ScalePart 2: Spectroscopic MethodISO 6271-1981 Clear LiquidsEstimation of Color by thePlatinum-Cobalt Scale3. Terminology3.1 For definitions of terms used in these test methods seeTerminology
8、D 883.4. Summary of Test Method4.1 In Test Method A, the color of the material to be testedis compared to a series of color standards with definedchromicity coordinates, prepared on one of three ways. Theresults are reported as the color standard, which best matchesthe sample.4.2 In Test Method B, t
9、he color of the material to be testedis compared to a series of platinum-cobalt color standards,designated by mg of Pt/mL of standard solution. The results arereported as the color standard, which best matches the sample(see Note 2).NOTE 2Color of liquids also can be measured by visible spectroscopy
10、and the results converted to any of several color scales. These results canbe converted to the APHA scale by appropriate manipulations, as forexample in Test Method D 5386.5. Significance and Use5.1 These test methods are suitable for quality control, asspecification tests, and for research. Color i
11、s an importantproperty of urethane products.6. Sampling6.1 Polyesters and polyethers usually contain moleculescovering an appreciable range of molecular weights. Thesehave a tendency to fractionate during solidification. Unless thematerial is a liquid or finely ground solid it is necessary to melt(u
12、sing no higher temperature than necessary) and mix the resinwell before removing a sample for analysis. Many polyols are1These test methods are under the jurisdiction of Committee D20 on Plastics andare the direct responsibility of Subcommittee D20.22 on Cellular MaterialsPlastics and Elastomers.Cur
13、rent edition approved Sept. 1, 2006. Published September 2006. Originallyapproved in 1988. Last previous edition approved in 1998 as D 4890 - 98(2003).2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStan
14、dards volume information, refer to the standards Document Summary page onthe ASTM website.3Available from American National Standards Institute (ANSI), 25 W. 43rd St.,4th Floor, New York, NY 10036.1*A Summary of Changes section appears at the end of this standard.Copyright ASTM International, 100 Ba
15、rr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.hygroscopic and care should be taken to provide minimumexposure to atmospheric moisture during the sampling.7. Purity of Reagents7.1 Purity of ReagentsReagent-grade chemicals shall beused in all tests. Unless otherwise ind
16、icated, it is intended thatall reagents shall conform to the specifications of the Commit-tee on Analytical Reagents of the American Chemical Society,where such specifications are available.4Other grades may beused, provided it is first ascertained that the reagent is ofsufficiently high purity to p
17、ermit its use without lessening theaccuracy of the determination.7.2 Purity of WaterUnless otherwise indicated, referencesto water shall be understood to mean reagent water as definedby Type IV or better of Specification D 1193.TEST METHOD AGARDNER COLOR8. Apparatus8.1 Gardner-Holdt Tubes, of clear
18、glass, with closed, flat,even bottoms, and having the following approximate dimen-sions and markings:8.1.1 A uniform internal length of 112 mm,8.1.2 A uniform internal diameter throughout the length ofthe tube of 10.75 mm, and8.1.3 An etched line around the outside of the tube 5 mmfrom the open end
19、and a second etched line around the outsideof the tube 13 mm from the open end.9. Reagents9.1 Cobalt Chloride SolutionPrepare a solution contain-ing 1 part by weight of cobalt chloride (CoCl23 6H2O) to 3parts of HCl (1 to 17).9.2 Ferric Chloride SolutionPrepare a solution containingapproximately 5 p
20、arts by weight of ferric chloride(FeCl33 6H2O) and 1.2 parts of HCl (1 to 17). Adjust to exactcolor equivalence to a freshly prepared solution containing 3 gof K2Cr2O7in 100 mL of H2SO4(sp gr 1.84).9.3 Hydrochloric Acid (1 to 17)Mix 1 volume of concen-trated hydrochloric acid (HCl, sp gr 1.19) with
21、17 volumes ofwater.9.4 Hydrochloric Acid (0.1 N)Prepare 0.1 N HCl.9.5 Potassium Chloroplatinate (K2Cr2O7).9.6 Potassium Dichromate (K2Cr2O7).9.7 Sulfuric Acid (sp gr 1.84)Concentrated sulfuric acid(H2SO4).10. Gardner Color Reference Standards510.1 The primary standards for color shall consist of sol
22、u-tions defined by their spectral transmittance in 1-cm cell withparallel sides. The chromaticity coordinates of these solutionsshall conform to those given in Table 1 when determined on a1-cm layer of the solution in accordance with Practice E 1164and Test Method E 308.10.2 For comparison, permanen
23、t solutions of known colorare more satisfactory. The approximate composition of solu-tions giving each of the 18 Gardner colors is also given inTable 1. The solutions shall be made from K2PtCl6in 0.1 N4Reagent Chemicals, American Chemical Society Specifications, AmericanChemical Society, Washington,
24、 DC. For suggestions on the testing of reagents notlisted by the American Chemical Society, see Analar Standards for LaboratoryChemicals, BDH Ltd., Poole, Dorset, U.K., and the United States Pharmacopeiaand National Formulary, U.S. Pharmacopeial Convention, Inc. (USPC), Rockville,MD.5The sole source
25、 of supply of the glass color standards and color standardsolutions known to the committee at this time is BYK-Gardner USA, 9104 GuilfordRoad, Columbia, MD 21046. If you are aware of alternative suppliers, pleaseprovide this information to ASTM International Headquarters. Your comments willreceive c
26、areful consideration at a meeting of the responsible technical committee,1which you may attend.TABLE 1 Gardner Reference Standard Color SolutionsGardner Color StandardNumberChromaticityCoordinatesA PotassiumChloroplatinate, g/1000mL of 0.1 NHClIron-Cobalt SolutionsPotassium Dichromate,g/100 mL Sulfu
27、ric AcidBxyFerric ChlorideSolution, mLCobalt ChlorideSolution, mLHydrochloric Acid, mL1 0.3190 0.3271 0.550 . . . . . . . . . 0.00392 0.3241 0.3344 0.865 . . . . . . . . . 0.00483 0.3315 0.3456 1.330 . . . . . . . . . 0.00714 0.3433 0.3632 2.080 . . . . . . . . . 0.01125 0.3578 0.3820 3.035 . . . .
28、. . . . . 0.02056 0.3750 0.4047 4.225 . . . . . . . . . 0.03227 0.4022 0.4360 6.400 . . . . . . . . . 0.03848 0.4179 0.4535 7.900 . . . . . . . . . 0.05159 0.4338 0.4648 . . . 3.8 3.0 93.2 0.078010 0.4490 0.4775 . . . 5.1 3.6 91.3 0.16411 0.4836 0.4805 . . . 7.5 5.3 87.2 0.25012 0.5084 0.4639 . . .
29、10.8 7.6 81.6 0.38013 0.5395 0.4451 . . . 16.6 10.0 73.4 0.57214 0.5654 0.4295 . . . 22.2 13.3 64.5 0.76315 0.5870 0.4112 . . . 29.4 17.6 53.0 1.04116 0.6060 0.3933 . . . 37.8 22.8 39.4 1.28017 0.6275 0.3725 . . . 51.3 25.6 23.1 2.22018 0.6475 0.3525 . . . 100.0 0.0 0.0 3.00AChromaticity coordinates
30、 for CIE standard illuminant C and the CIE 1931 (2) standard observer.BThe dichromate color standards have been found to be less reliable than chloroplatinate or iron-cobalt color standards. They are included in Table 1 for reference only.D 4890 062HCl, or, in the darker colors, from stock solutions
31、 of FeCl3,CoCl2, and HCl (see 9.1, 9.2, and 9.3).10.3 Solutions of K2Cr2O7(sp gr 1.84) may be used asreference standards. The approximate composition of thesestandards is also given in Table 1. Each solution must befreshly made for the color comparison, using gentle heat, ifnecessary, to effect solu
32、tion.10.4 Secondary reference standards may be obtained in theform of 18 colored glass disks, which are set into a pair oflarger, plastic disks and the latter mounted to rotate in ahousing for holding the sample tube and glass disk in close andfixed proximity.11. Procedure11.1 Fill the tube with sam
33、ple, free of solid particles or airbubbles, so that the apparent upper edge of the liquid meniscusis even with the lower etched line on the tube.11.2 Determine the color by comparison with the referencestandard solutions prescribed in Table 1, by comparing thesample and the standard in Gardner-Holdt
34、 viscosity tubes asdescribed. Make the comparison at 25 6 5C by placing tubesclose together and looking through them against a whitebackground or by comparison to the standards in a color disk.12. Report12.1 Report the color of the sample in terms of the Gardnerstandard number that is nearest to it
35、in color. If the sampleappears exactly halfway between two standards, report thecolor number of the darker standard.13. Precision and Bias13.1 PrecisionAttempts to develop a precision and biasstatement for this test method have not been successful. Forthis reason, data on precision and bias cannot b
36、e given;however, the precision is expected to be equivalent to thatreported in ISO 4630-1:2004. Because this test method doesnot contain a numerical precision and bias statement, it shallnot be used as a referee test method in case of dispute. Anyonewishing to participate in the development of preci
37、sion and biasdata should contact the Chairman, Subcommittee D20.22(Section D20.22.01), ASTM, 100 Barr Harbor Drive, WestConshohocken, PA 19428.13.1.1 RepeatabilityBased on ISO 4630-1:2004, it wouldbe expected that two replicate test results, run on the same day,using the same equipment, by the same
38、analyst, should beconsidered to be different only if they differ by more than onecolor number.13.1.2 ReproducibilityBased on ISO 4630-1:2004,itwould be expected that two test results, run on different days,using different equipment, by the different analysts, should beconsidered to be different only
39、 if they differ by more than twocolor numbers.13.2 BiasThe bias of this test method has not yet beendetermined.TEST METHOD BAPHA COLOR14. Apparatus14.1 Nessler Tubes, matched 100-mL, tall-form.15. Reagents15.1 Hydrochloric Acid (sp gr 1.19)Concentrated hydro-chloric acid (HCl).15.2 Potassium Chlorop
40、latinate (K2PtCl6).15.3 Cobaltous Chloride Hexahydrate (CoCl26H2O).16. Preparation of Color Standards16.1 Measure 500 mL of water into a 1000-mL volumetricflask. Add 100 mL of the HCl and mix well. Weigh 1.245 g ofK2PtCl6to the nearest 1 mg and transfer to the flask (see Note3). Add 1.0 g of crystal
41、lized CoCl26H2O. Dilute the solutionin the flask to the mark with water and mix thoroughly. Thecolor of this standard solution is equivalent to 500 units (500mg metallic platinum/L), that is each millilitre of standardcontains 0.5 mg of metallic platinum.NOTE 3If potassium chloroplatinate is not ava
42、ilable, dissolve 0.500 gof pure metallic platinum in aqua regia with the aid of heat; then removeHNO3by repeated evaporation with fresh portions of HCl. Dissolve thisproduct as directed in 16.1.16.2 Prepare the required color standards by diluting theNo. 500 standard solution as shown in Table 2. If
43、 more exactcolor comparison is desired, prepare additional standards tosupplement those given below. One color unit is equivalent to1 mg metallic platinum/litre. Protect these standards againstevaporation and contamination when not in use.17. Procedure17.1 Transfer 100 mL of the sample to one of two
44、 matched100-mL tall-form Nessler tubes. Fill the second tube to themark with the standard that seems to match the color of thesample as indicated by a preliminary estimation. Compare thecolors of the sample and the standard by viewing verticallydown through the tubes against a white background. Repl
45、acethe liquid in the second tube with lighter or darker standardsuntil an exact match is obtained.TABLE 2 APHA Color StandardsColor Standard NumberNumber 500 Standard,mLWater, mL1 0.2 99.83 0.6 99.45 1.0 99.010 2.0 98.015 3.0 97.018 3.6 96.420 4.0 96.025 5.0 95.030 6.0 94.040 8.0 92.050 10.0 90.060
46、12.0 88.070 14.0 86.080 16.0 84.090 18.0 82.0100 20.0 80.0120 24.0 76.0140 28.0 72.0160 32.0 68.0180 36.0 64.0200 40.0 60.0300 60.0 40.0400 80.0 20.0500 100.0 0.0D 4890 06318. Report18.1 Report the color of the sample in terms of the colorstandard number that is nearest to it in color. If the sample
47、appears exactly halfway between two standards, report thecolor number of the darker standard.19. Precision and Bias19.1 PrecisionAttempts to develop a precision and biasstatement for this test method have not been successful. Forthis reason, data on precision and bias cannot be given;however, the pr
48、ecision is expected to be equivalent to thatreported in ISO 6271-1981. Because this test method does notcontain a numerical precision and bias statement, it shall not beused as a referee test method in case of dispute. Anyonewishing to participate in the development of precision and biasdata should
49、contact the Chairman, Subcommittee D20.22(Section D20.22.01), ASTM, 100 Barr Harbor Drive, WestConshohocken, PA 19428.19.1.1 RepeatabilityBased on ISO 6271-1981, it wouldbe expected that two replicate test results, run on the same day,using the same equipment, by the same analyst, should beconsidered to be different only if they differ by more than5.1 % relative.19.1.2 ReproducibilityBased on ISO 6271-1981, it wouldbe expected that two test results, run on different days, usingdifferent equipment, by the different analysts, should be con-sidered to be dif
