1、Designation: D 7133 05Standard Test Method forPolyurethane Raw Materials: Instrumental Measurement ofTristimulus CIELAB Color and Yellowness Index of Liquids1This standard is issued under the fixed designation D 7133; the number immediately following the designation indicates the year oforiginal ado
2、ption or, in the case of revision, 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. Scope1.1 This test method provides an instrumental method formeasuring the CIEL
3、AB color and Yellowness Index (YI) ofliquid polyurethane raw materials. The CIELAB and YI resultsare derived from mathematical manipulation of CIE tristimulusvalues in accordance with Practices E 308 and E 313, respec-tively.1.2 See Section 5 for cautions in using this test method.1.3 This standard
4、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.NOTE 1There is no equivalent ISO
5、standard.2. Referenced Documents2.1 ASTM Standards:2D 883 Terminology Relating to PlasticsD 1193 Specification for Reagent WaterE 180 Practice for Determining the Precision of ASTMMethods for Analysis and Testing of Industrial and Spe-cialty ChemicalsE 284 Terminology of AppearanceE 308 Practice for
6、 Computing the Colors of Objects byUsing the CIE SystemE 313 Practice for Calculating Yellowness and WhitenessIndices from Instrumentally Measured Color CoordinatesE 691 Practice for Conducting an Interlaboratory Study toDetermine the Precision of a Test Method3. Terminology3.1 DefinitionsFor defini
7、tions of terms that appear in thistest method, refer to Terminologies E 284, D 883, and theterminology section of Practice E 308.4. Summary of Test Method4.1 The color of the total transmitted light is measured by aspectrophotometer in CIE tristimulus values under CIE stan-dard illuminant D65 and CI
8、E 1964 supplementary standardobserver commonly called the 10 standard observer. Thesevalues are then converted by the appropriate equations to theCIELAB color scale and the Yellowness Index. L*a*b* and YIvalues are reported.5. Significance and Use5.1 CIELAB is a visual-based scale that can be used t
9、ospecify color and set color tolerances for the polyurethaneindustry.5.2 Yellowness Index specifies the degree of departure ofthe sample from colorless towards yellow. This index is onlysuitable for clear liquids with degrees of saturation in yellow(dominant transmission wavelength in the 570 to 580
10、 nmrange). It can be used to set tolerances for appropriatepolyurethane raw materials.5.3 This test method does not include provisions for mate-rials with fluorescence or visible haze (usually greater than 5 %haze).5.4 Before proceeding with this test method, make referenceto the specification of th
11、e material being tested. Any testspecimen preparation, conditioning, dimensions, or testingparameters or combination thereof, covered in the materialsspecification shall take precedence over those mentioned in thistest method. If there are no material specifications, then thedefault conditions apply
12、.6. Interferences6.1 This test method is to be used to compare samples onlywhen they are measured under the same conditions.6.1.1 The medium in the cuvette used during standardiza-tion of the instrument will have an effect on the measuredresults. Light mineral oil is recommended, however, distilledw
13、ater can be used as a substitute but a note of the substitutionmust be included in any report of the results.6.1.2 The temperature of the sample is also expected toaffect the results obtained.1This test method is under the jurisdiction of ASTM Committee D20 on Plasticsand is the direct responsibilit
14、y of Subcommittee D20.22 on Cellular MaterialsPlastics and Elastomers.Current edition approved Dec. 15, 2005. Published January 2006.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume infor
15、mation, refer to the standards Document Summary page onthe ASTM website.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.7. Apparatus7.1 InstrumentA hemispherical geometry (integratingsphere) spectrophotometer capable of total transmi
16、ssion (TT-RAN) CIE tristimulus measurement through a cuvette. TT-RAN includes both the regularly transmitted portion and thediffused portion of the incident light. The instrument must becapable of converting CIE XYZ tristimulus values to theCIELAB color scale as defined in Practice E 308 using CIED6
17、5 standard illuminant and 10 standard observer. Theinstrument must also be capable of converting CIE XYZtristimulus values to the Yellowness Index value defined inPractice E 313 using CIE D65 standard illuminant and 10standard observer. The instrument is to meet the manufactur-ers requirements for c
18、alibration. For highly transparentsamples, such as the polyols below, spectrophotometers ortristimulus colorimeters without a spherical geometry can beused with equivalent results.7.2 Sample CuvettesThe cuvette must have a 20 6 0.06mm pathlength. The entrance and exit windows shall beparallel, color
19、less, clear and unaffected by the material beinganalyzed. The optical properties of the cuvette used duringstandardization of the instrument and the cuvette used formeasuring samples (if not the same cuvette) must be matched.This can be determined by proving that the variation, if any, inthe differe
20、nt cuvettes used do not affect the measured value ofa standard sample. Glass or plastic cuvettes can be used.8. Reagents8.1 Mineral OilColorless NF or FCC grade light mineraloil.8.2 Distilled WaterColorless distilled water conformingto Type IV of Specification D 1193.9. Sampling and Test Specs and U
21、nits9.1 Test samples are to be homogeneous and representativeof the liquid being tested.9.2 Do not touch the entrance and exit windows of thecuvette through which incident and transmitted light will passexcept to clean them.9.3 The CIELAB values, L*, a*, and b*, have no unitsassociated with them.9.4
22、 The Yellowness Index value, YI, has no unit associatedwith it.10. Calibration and Standardization10.1 Calibration procedures vary from manufacturer tomanufacturer. They are important to ensure accurate data.Include the following periodic system verification steps:10.1.1 Wavelength Scale Verificatio
23、nThis can be donewith a didymium filter.10.1.2 Photomeric Scale VerificationThis is to be done inaccordance with manufacturers instructions with a certifiedliquid standard. An APHA standard is suitable. Linearity isestablished using at least two different standard concentrations.10.1.3 Selection of
24、Instrument Variables10.1.3.1 Select CIE illuminant D65 and 10 standard ob-server.10.1.3.2 Select the total transmission (TTRAN) mode un-less instructed by the manufacturer to use a different mode forthe verification procedure.10.2 Pour mineral oil into a clean cuvette. Ensure that liquidcompletely c
25、overs the measurement area and that no airbubbles remain below the meniscus. Follow the manufacturersinstructions to perform the following steps before sampleanalyses and at least every four hours when samples are beinganalyzed.10.2.1 Full-Scale StandardizationUse a cuvette filledwith mineral oil to
26、 set the top of the neutral axis scale to 100by simulating the case where all light is transmitted through thesample.10.2.2 Zero Scale StandardizationSet the bottom of theneutral axis scale to 0 by simulating the case where all light isabsorbed by the sample. Block the light beam by replacing thecuv
27、ette with an opaque object supplied by the manufacturer.11. Conditioning11.1 Condition liquids for measurement at 23 6 2C unlessotherwise specified by contract or relevant material specifica-tion.NOTE 2The pure 4,4 isomer of methylenebis-(phenylisocyanate)(MDI) is a solid at 23C. Condition it for me
28、asurement at 50 6 2C.12. Procedure12.1 Sample PreparationPour the sample into a cleancuvette. Ensure that liquid completely covers the measurementarea and that no air bubbles remain below the meniscus.12.2 Selection of Instrument Variables12.2.1 Select CIE illuminant D65 and 10 standard observer.12.
29、2.2 Select the total transmission (TTRAN) mode.12.3 Selection of Color Scale and IndexSelect theCIELAB color calculated as defined in Practice E 308 and theYellowness Index calculated as defined in Practice E 313.12.4 Analysis12.4.1 The mineral oil is read as a sample to ensure that theinstrument is
30、 set up and reading correctly prior to sampleanalysis. Therefore, measure the cuvette of mineral oil induplicate by following the manufacturers instructions forsample measurement in TTRAN mode. The average of tworeadings is to meet the following tolerances: L* =100 6 0.1;a*= 0 6 0.1; b*= 0 6 0.1 and
31、 YI = 0 6 0.25.12.4.2 Measure the cuvette of the sample in duplicate byfollowing the manufacturers instructions for sample measure-ment in TTRAN mode.12.4.3 Average the resulting values for L*a*b* and YI.13. Calculation13.1 The instrument software is to automatically calculatethe L*a*b* values in ac
32、cordance with the equations defined inPractice E 308 and the YI value in accordance with theequation in Practice E 313.14. Report14.1 The report shall include the following:14.1.1 Date of measurement.14.1.2 Sample description and identification.D713305214.1.3 Any changes from the recommended paramet
33、ers orconditions (for example, temperature of sample if differentfrom 22 6 2C or 50 6 2C for pure MDI, the use of a liquidother than mineral oil for standardization).14.1.4 L*a* b* values and YI value to two significantfigures to the right of the decimal point.15. Precision and Bias15.1 The precisio
34、n data presented in this test method arerepresentative of the conditions defined in the standard. How-ever, material preparation and specific test conditions in thematerial specification can result in a deviation from theprecision and bias requiring separate study.15.2 Table 1 is based on a round ro
35、bin conducted in 2001 inaccordance with Practice E 180 involving four materials testedby ten laboratories. For each material, all the samples wereprepared at one source, but the individual specimens wereprepared at the laboratories that tested them. Each test resultwas the average of two individual
36、determinations (replicates).Each laboratory obtained two test results for each material.15.3 Table 2 is based on a round robin conducted in 2001involving two materials tested by four laboratories. For eachmaterial, all the samples were prepared at one source, but theindividual specimens were prepare
37、d at the laboratories thattested them. Each test result was the average of two individualdeterminations (replicates). Each laboratory obtained two testresults for each material. (WarningThe explanation of “r”and “R”(15.4 through 15.4.3) are only intended to present ameaningful way of considering the
38、 approximate precision ofthe test method. The data in Table 1 and Table 2 are not to beapplied to acceptance or rejection of materials, as these dataapply only to the materials tested in the round robin and areunlikely to be rigorously representative of other lots, formula-tions, conditions, materia
39、ls, or laboratories. Users of this testmethod are to apply the principles outlined in Practice E 180 orE 691 to generate data specific to their material and laboratory(or between specific laboratories). The principles of 15.4through 15.4.3 would then be valid for such data.)15.4 Precision15.4.1 Repe
40、atability, (r)Comparing two replicates for thesame material, obtained by the same operator, using the sameequipment on the same day. The two replicate results are to bejudged not equivalent if they differ by more than the r value forthat material.15.4.2 Reproducibility, (R)Comparing two results, eac
41、hthe mean of replicates, for the same material, obtained bydifferent operators, using different equipment in differentlaboratories on different days. The two test results are to bejudged not equivalent if they differ by more than the R valuefor that material.TABLE 1 CIELAB Round Robin DataL* valuesS
42、tandard Material Viscosity Average SrASRBrCRDMineral OilPMDI A 200 mPa s(200 cP)44.93 0.05 0.76 0.15 2.13PMDI B 750 mPa s(750 cP)1.64 0.03 0.26 0.10 0.74Polyol A 475 mPa s(475 cP)99.88 0.03 0.14 0.07 0.40Polyol B 6500 mPa s(6500 cP)96.01 0.11 0.85 0.31 2.37a* valuesStandard Material Viscosity Averag
43、e SrASRBrCRDMineral OilPMDI A 200 mPa s(200 cP)45.80 0.03 0.26 0.07 0.72PMDI B 750 mPa s(750 cP)9.17 0.12 1.01 0.33 2.82Polyol A 475 mPa s(475 cP)0.13 0.00 0.02 0.01 0.07Polyol B 6500 mPa s( 6500 cP)1.82 0.03 0.26 0.07 0.72b* valuesStandard Material Viscosity Average SrASRBrCRDMineral OilPMDI A 200
44、mPa s(200 cP)72.88 0.09 4.72 0.25 13.22PMDI B 750 mPa s (750 cP) 2.37 0.08 0.44 0.23 1.23Polyol A 475 mPa s(475 cP)0.63 0.01 0.10 0.03 0.29Polyol B 6500 mPa s( 6500 cP)12.32 0.06 1.33 0.16 3.74ASr= within laboratory standard deviation of individual replicates.BSR= between laboratories standard devia
45、tion of means of replicates.Cr = within laboratory critical interval between individual replicates (2.8 3 Sr)repeatability.DR = between laboratory critical interval between means of replicates (2.8 3 SR)reproducibility.D713305315.4.3 Any judgment in accordance with 15.4.1 and 15.4.2would have an app
46、roximate 95 % (0.95) probability of beingcorrect.15.5 There are no recognized standards by which to esti-mate the bias of this test method.15.6 Supporting data are available from ASTM Headquar-ters. Request RR: D20-1242.16. Keywords16.1 CIELAB; color; colormetric analysis; instrumentalmeasurement; i
47、socyanates; L*a*b*; light; polyols; polyure-thane raw materials; polyurethanes; spectrophotometry; trans-mission; tristimulus; yellowness index; YIBIBLIOGRAPHY(1) HunterLab, “The Science and Technology of Appearance Measure-ment”.(2) Billmeyer, F. W., Jr., and Chen, Y., “On the Measurement of Haze,”
48、Color Research and Application, Vol 10, 1985, pp. 219224.(3) Hunter, R. S., and Harold, R. W., The Measurement of Appearance,2nd ed., Wiley, New York, 1987, Table 16.1.(4) Eckerle, K. L., Chang, S., and Hsia, J. J., “Calibration in 1976 and1983 of Didymium Glass Filters Issued as NBS Standard Refere
49、nceMaterials,” Color Research and Application, Vol 10, 1985, pp. 32-37.(5) Van den Akker, J. A., “Wave-length Calibration of Spectrophotom-eters,” Journal, Optical Society of America, Vol 33, 1943, pp. 257-259.(6) New Series of Ceramic Colour Standards,” Color Research andApplication, Vol 9, 1984, pp. 119-120.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 paten
