1、Designation: C1501 14Standard Test Method forColor Stability of Building Construction Sealants asDetermined by Laboratory Accelerated WeatheringProcedures1This standard is issued under the fixed designation C1501; the number immediately following the designation indicates the year oforiginal adoptio
2、n or, in the case of revision, 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.1. Scope1.1 This test method describes laboratory acceleratedweathering procedures usin
3、g either fluorescent ultraviolet orxenon arc test devices for determining the color stability ofbuilding construction sealants.1.2 Color stability rankings provided by these two proce-dures may not agree.1.3 The values stated in SI units are to be regarded as thestandard. Values given in parentheses
4、 are for information only.1.4 There is no equivalent ISO standard for this test method.1.5 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
5、and determine the applica-bility of regulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:2C717 Terminology of Building Seals and SealantsC1442 Practice for Conducting Tests on Sealants UsingArtificial Weathering ApparatusD1729 Practice for Visual Appraisal of Colors and Colo
6、rDifferences of Diffusely-Illuminated Opaque MaterialsD2244 Practice for Calculation of Color Tolerances andColor Differences from Instrumentally Measured ColorCoordinatesE284 Terminology of AppearanceE691 Practice for Conducting an Interlaboratory Study toDetermine the Precision of a Test MethodE17
7、7 Practice for Use of the Terms Precision and Bias inASTM Test MethodsE1164 Practice for Obtaining Spectrometric Data for Object-Color EvaluationG113 Terminology Relating to Natural and Artificial Weath-ering Tests of Nonmetallic MaterialsG151 Practice for Exposing Nonmetallic Materials in Accel-era
8、ted Test Devices that Use Laboratory Light SourcesG154 Practice for Operating Fluorescent Ultraviolet (UV)Lamp Apparatus for Exposure of Nonmetallic MaterialsG155 Practice for Operating Xenon Arc Light Apparatus forExposure of Non-Metallic Materials2.2 CIE Documents:CIE Publication Number 85: 1989,
9、Technical Report-SolarSpectral Irradiance33. Terminology3.1 DefinitionsDefinitions of the following terms arefound in Terminology C717: standard conditions, compound,cure, sealant, and substrate. Definitions of the following termsare found in Terminology G113: sample, file specimen, controlmaterial,
10、 fluorescent ultraviolet lamps, xenon arc, irradiance,radiant exposure, spectral power distribution, solar radiation-ultraviolet, solar radiation-visible.4. Summary of Test Method4.1 Specimens for this procedure are prepared in which thesealant to be tested adheres to flat aluminum panels. While any
11、surface can be specified and used, this test method wasdeveloped with aluminum panels. At least four replicates ofeach sealant being tested are required. After curing, onereplicate of each sealant being tested is retained as a filespecimen and at least three replicates are exposed to actinicradiatio
12、n, heat and moisture.At the end of the exposure period,the test sealant is examined for color change by comparison tothe unexposed file specimen.4.2 As recommended in Practice G151 Section 4.2, unlessseveral test sealants are exposed to determine their relative1This test method is under the jurisdic
13、tion ofASTM Committee C24 on BuildingSeals and Sealants and is the direct responsibility of Subcommittee C24.40 onWeathering.Current edition approved June 1, 2014. Published July 2014. Originally approvedin 2001. Last previous edition approved in 2009 as C150109. DOI: 10.1520/C1501-14.2For reference
14、d ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.3CIE Central Bureau, Vienna, Kegelgasse 27, A-1030 Wien, AustriaCopyright A
15、STM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States1color stabilities, one or two control sealants of similar compo-sition and construction to the test specimen and having knowncolor stability should be exposed simultaneously with the testspecimen t
16、o rank the color stability of the latter compared withthe color stability of the control(s).5. Significance and Use5.1 This test method is intended to induce color changes insealants, as well as their constituent pigments, associated withend-use conditions, including the effects of sunlight, moistur
17、e,and heat. The exposures used in this test method are notintended to simulate the color change of a sealant caused bylocalized weathering phenomena, such as atmosphericpollution, biological attack, and saltwater exposure.5.2 When conducting exposures in devices that use labora-tory light sources, i
18、t is important to consider how well theartificial test conditions will reproduce property changes andfailure modes associated with end-use environments for thesealant being tested. Information on the use and interpretationof data from accelerated exposure tests is provided in PracticeG151.5.3 When t
19、his test method is used as part of a specification,exact procedure, test conditions, test duration and evaluationtechnique must be specified. Results obtained between the twoprocedures may vary, because the spectral power distributionof the light sources (fluorescent UV and xenon arc) differ.Sealant
20、s should not be compared to each other based on theresults obtained in different types of apparatus.5.4 These devices are capable of matching ultraviolet solarradiation reasonably well. However, for sealants sensitive tolong wavelength UV and visible solar radiation, the absence ofthis radiation in
21、the fluorescent UV apparatus can distort colorstability ranking when compared to exterior environmentexposure.NOTE 1Refer to Practice G151 for full cautionary guidance regardinglaboratory weathering of non-metallic materials.6. Apparatus6.1 Aluminum PanelsApply sealant to four aluminumpanels, alloy
22、3003 H14, dimensions, 152 mm by 76 mm by0.64 mm thick (6 by 3 by 0.025 in. thick), using rectangularBrass Frame described in 6.3. Other substrate materials areacceptable when specified.6.2 Spatula, steel, about 150 mm (6 in.) long.6.3 Rectangular Brass Frame, with outside dimensions ofapproximately
23、152 mm by 76 mm, and inside dimensions 75mm by 65 mm by 3.0 mm (3 in. long by 2.5 in. wide by 0.125in. deep).6.4 Thin Bladed Knife.6.5 Color Evaluation Apparatus:6.5.1 Lighting Equipment, to evaluate color difference ac-cording to Practice D1729 or,6.5.2 Spectrophotometer, complying with Practice E1
24、164;or,6.5.3 Colorimeter, complying with Test Method D2244.6.6 Cleaning Solvent, isopropyl alcohol.6.7 Test ChamberChoice of type of apparatus shall be bymutual agreement among the interested parties. Because ofdifferences in test conditions, test results may differ with thetype of apparatus used. C
25、onsult Practices G154 and G155 fordifferences in the spectral power distributions of the exposuresources and Practice C1442 for the differences in test param-eters in the two types of apparatus specified. The test cycleshave been used by historical convention and may not ad-equately simulate the eff
26、ects of outdoor exposure of sealants.Other cycles can be used by mutual agreement of all concernedparties.6.7.1 Fluorescent UV/Condensation ApparatusOperatethe device in accordance with the procedure in Practice C1442,Section 7.3.6.7.2 Xenon Arc Light ApparatusOperate the device inaccordance with th
27、e procedure in Practice C1442, Section 7.2.NOTE 2CIE Publication No. 85:1989 provides data on solar spectralirradiance for typical atmospheric conditions, which can be used as a basisfor comparing laboratory light sources with daylight. For example, globalsolar irradiance is 0.68 W/(m2 nm) at 340 nm
28、 as presented in CIE 85table 4.6.7.3 MoistureThe test specimens may be exposed tomoisture in the form of water spray, condensation, immersion,or high humidity as agreed on by the mutual parties. Refer toPractice G151 Section 6.6 for discussion of the various formsof moisture in accelerated test devi
29、ces.7. Procedure7.1 Condition sufficient sealant in an original closed con-tainer for at least 24 h at standard conditions as defined inTerminology C717 and away from light.7.2 Prepare at least four sealant test specimens and at leastfour of the control material, if used, on aluminum panels. Cleanth
30、e aluminum panels using cleaning solvent. Allow solvent todry before applying sealant.7.3 Position the brass frame on the aluminum panel andoverfill the entire frame with conditioned sealant. Strike off flatusing the spatula. Immediately separate the sealant from theframe by running a thin bladed kn
31、ife along the inside of theframe. Lift the frame from the aluminum panel.7.4 Cure the test specimens at standard conditions for 21days. Other conditions for curing are acceptable when specifiedprovided they meet the following requirements: (1) the curingperiod shall not exceed 21 days, and (2) the t
32、emperature duringthe curing period shall not exceed 50C (122F). Keep one testspecimen as an unexposed file specimen and store at standardconditions.7.5 Place at least three of the cured specimens and thecontrol material if used, in the weathering apparatus with thesealant surface facing the radiatio
33、n source and positioned at thespecified distance from the source. Specimens should beconfined to an exposure area in which the irradiance is at least90 % of the irradiance at the center of the exposure area.Unless it is known that irradiance uniformity meets thisrequirement, use one of the procedure
34、s described in PracticeG151, Section 5.1.4 to ensure equal radiant exposure on allspecimens or compensation for differences within the exposureC1501 142chamber. If the specimens do not completely fill the racks, fillthe empty spaces with blank metal panels to maintain the testconditions within the c
35、hamber.7.6 Apparatus shall be operated continuously. However, ifthe test needs to be interrupted to perform routine maintenanceor inspection, it should be during a dry period.7.7 Expose the specimens for a mutually agreed uponspecified duration in hours or radiant energy. Because of theoption of ope
36、rating the xenon arc apparatus at an irradiancelevel of 0.35 W/(m2nm) at 340 nm as well as 0.51 W(m2nm)at 340 nm, test duration is specified in terms of radiant energy.The time in hours at the irradiance level used is determinedaccording to the formula in Annex A1.2.1 in Practice C1442.Evaluate spec
37、imens in the fluorescent UV apparatus at 1000-hexposure intervals, where applicable. Evaluate specimens inthe xenon arc apparatus operated at an irradiance level of 0.51W/(m2nm) at 340 nm at intervals of 1835 kJ/(m2nm) at 340nm. The minimum exposure duration shall be sufficient toproduce a statistic
38、ally significant change in color in the leastcolor stable building construction sealant.7.8 After artificial weathering, condition the samples atstandard conditions for at least 2 h before color evaluation.7.9 The color measuring instrument should be set up to readin the CIE L*a*b* color scale with
39、illuminant C or D65 and10 observer, specular component included. Measure the colorvalues of each test specimen and control, if used, prior toexposure and after each exposure. The edges of the specimensmay be trimmed to compensate for shrinkage and provide asecure fit in the color-measuring instrumen
40、t. Make a minimumof three measurements per specimen, moving or rotating thespecimen so as to measure different areas. Using the CIELABcolor-difference formula described in Test Method D2244,calculate E*abbetween each exposed specimen and its filespecimen (unexposed counterpart).7.10 As an alternativ
41、e to the instrumental color measure-ment procedure in 7.9, evaluate color differences betweenexposed and unexposed file specimen sealant using PracticeD1729.7.11 Pass/fail evaluations based on either absolute colorchange after a specified exposure period or comparativestabilities, should be made usi
42、ng the variability determined forthe combined exposure and color measurement so that statis-tically significant pass/fail judgements can be made.7.12 The duration of exposure required to obtain a specifiedlevel of color difference can be determined by interpolationfrom a plot of E*abversus time or c
43、umulative radiantexposure. This approach permits the rate of color change to bedetermined and weatherability to be more accurately evaluatedthat in tests based on change after a specified exposure period.8. Report8.1 In addition to the items specified in the Report section ofPractice G151, the repor
44、t shall include the following for eachsample tested:8.1.1 Type, manufacturer and model of laboratory acceler-ated weathering apparatus,8.1.1.1 Irradiance level and actual time (number of hours) inweathering apparatus.8.1.2 Identification of sealant specimen tested, and controlsused, if any.8.1.3 Sea
45、lant cure conditions employed,8.1.4 Qualitative visual color differences as specified inPractice D1729 or quantitative color difference as specified inPractice D2244.8.1.5 Variations, if any, from the specified test procedure.9. Precision and Bias9.1 The precision of this test method is based on ani
46、nterlaboratory study of C1501, Standard Test Method forColor Stability of Building Construction Sealants as Deter-mined by Laboratory Accelerated Weathering Procedures,conducted in 2005. Results in this study were obtained fromeight laboratories reporting fluorescent UV exposure and fourlaboratories
47、 reporting xenon-arc exposure, testing four differ-ent sealants. Each participating laboratory reported three rep-licate test results, at each time interval, for every material. Theexposure times ranged from 250 to 3,000 h with colormeasurements made on the same specimen after each 250-hinterval. Ho
48、wever, test results for all exposure intervals werenot reported by each laboratory. Except for the use of only fourlaboratories for tests using the xenon arc procedure, PracticeE691 was followed for the design and analysis of the data. Thedetails are given in an ASTM research report.49.1.1 Repeatabi
49、lity, Limit (r)Two test results obtainedwithin one laboratory shall be judged not equivalent if theydiffer by more than the “r” value for that material; “r”istheinterval representing the critical difference between two testresults for the same material, obtained by the same operatorusing the same equipment on the same day in the samelaboratory.9.1.2 Reproducibility, Limit (R)Two test results shall bejudged not equivalent if they differ by more then the “R” valuefor that material; “R” is the interval representing the criticaldifference between two test results for
