1、SSPC-Paint 36April 1, 20061SSPC: The Society for Protective CoatingsPAINT SPECIFICATION NO. 36Two-Component Weatherable Aliphatic Polyurethane Topcoat,Performance-Based1. Scope1.1 This specifi cation covers the requirements for a high- performance two-component UV-stable polyurethane topcoat (ASTM D
2、 16, Type V polyurethane). It is intended as a topcoat that provides excellent color and gloss retention, not as a thick-section elastomeric coating.1.2 Coatings meeting the requirements of this specifi cation are generally suitable for exposures in environmental zones 1A (interior, normally dry), 1
3、B (exterior, normally dry), 2A (frequently wet by fresh water, excluding immersion), 2B (frequently wet by salt water, excluding immersion), 3B (chemical exposure, neutral), and 3C (chemical exposure, alkaline).1.3 The specifi ed coating is intended for application by brush, spray, or roller. It is
4、generally applied over a primer or intermediate coating.2. Description2.1 This coating is typically based on a hydroxyl-functional polyol resin and an aliphatic polyisocyanate co-reactant.2.2 WEATHERING LEVELS: This specifi cation contains three levels of accelerated and South Florida weathering per
5、formance (see Section 6.2). 3. Referenced Standards3.1 The latest issue, revision, or amendment of the refer-enced standards in effect on the date of invitation to bid shall govern, unless otherwise specifi ed. Standards marked with an asterisk (*) are referenced only in the Notes or the Appendix, w
6、hich are not requirements of this specifi cation.3.2 If there is a confl ict between the requirements of any of the cited referenced standards and this specifi cation, the requirements of this specifi cation shall prevail.3.3 SSPC STANDARD:Guide 13 Guide for the Identifi cation and Use of Industrial
7、 Coating Materials in Computerized Product Databases3.4 ASTM INTERNATIONAL STANDARDS:1D 16 Standard Terminology for Paint, Related Coatings, Materials, and ApplicationsD 523 Standard Test Method for Specular Gloss* D 562 Standard Test Method for Consistency of Paints Measuring Krebs Unit (KU) Viscos
8、ity Using a Stormer-Type Viscometer* D 968 Standard Test Methods for Abrasion Resistance of Organic Coatings by Falling AbrasiveD 1014 Standard Practice for Conducting Exterior Exposure Tests of Paints and Coatings on Metal Substrates* D 1296 Standard Test Method for Odor of Volatile Solvents and Di
9、luents* D 1308 Standard Test Method for Effect of Household Chemicals on Clear and Pigmented Organic Finishes* D 1475 Standard Test Method for Density of Liquid Coatings, Inks, and Related Products* D 1535 Standard Practice for Specifying Color by the Munsell System* D 1640 Standard Test Methods for
10、 Drying, Curing, or Film Formation of Organic Coatings at Room TemperatureD 1849 Standard Test Method for Package Stability of PaintD 2244 Standard Practice for Calculation of Color Tolerances and Color Differences from Instrumentally Measured Color Coordinates* D 2369 Standard Test Method for Volat
11、ile Content of Coatings* D 2371 Standard Test Method for Pigment Content of Solvent-Reducible Paints* D 2621 Standard Test Method for Infrared Identifi cation of Vehicle Solids from Solvent-Reducible Paints* D 2794 Standard Test Method for Resistance of Organic Coatings to the Effects of Rapid Defor
12、mation (Impact)* D 3359 Standard Test Methods for Measuring Adhesion by Tape Test* D 3719 Standard Test Method for Quantifying Dirt Collection on Coated Exterior Panels1ASTM International, 100 Barr Harbor Drive, West Conshohocken, PA 19428-2959. Standards available online from http:/www.astm.org.SSP
13、C-Paint 36April 1, 20062D 3925 Standard Practice for Sampling Liquid Paints and Related Coatings* D 4214 Standard Test Methods for Evaluating Degree of Chalking of Exterior Paint FilmsD 4587 Standard Practice for Fluorescent UV-Condensation Exposures of Paint and Related Coatings* D 5402 Standard Pr
14、actice for Assessing the Solvent Resistance of Organic Coatings Using Solvent Rubs* D 5590 Test Method for Determining the Resistance of Paint Films and Related Coatings to Fungal Defacement by Accelerated Four-Week Agar Plate Assay3.5 AMERICAN NATIONAL STANDARDS INSTITUTE (ANSI) STANDARD:2Z129.1 Ha
15、zardous Industrial Chemicals - Precautionary Labeling3.6 AMERICAN ASSOCIATION OF STATE HIGHWAY AND TRANSPORTATION OFFICIALS (AASHTO) STAN-DARD:3TP 67-03 Standard Method of Test for Analysis of Structural Steel Coatings for Isocyanate Content4. Composition Requirements4.1 RESIN REQUIREMENT: The curin
16、g agent shall be an aliphatic polyisocyanate. The total coating binder solids shall be made up of at least 17% polyisocyanate by weight. The method and formula for determining isocyanate content, developed by AASHTO as TP 67, is shown in the Annex. 4.2 VOC CONTENT: See Note 10.1.5. Requirements of L
17、iquid Coating5.1 PACKAGE STABILITY: Package stability shall be tested in accordance with ASTM D 1849. Storage conditions shall be 30 days at 52 1 C (126 2 F). A change in consis-tency of greater than 10 Krebs units or noncompliance with the application requirements shall be cause for rejection.5.2 A
18、PPLICATION PROPERTIES: All guidance provided by the manufacturer regarding mixing of multicomponent products, thinning requirements, induction times, and special application requirements shall be followed. Following the manufacturers recommendations, the coating shall be easily applied by brush, rol
19、ler, or spray. The coating shall show no streaking, running, sagging, or other defects during applica-tion or while drying.6. Weathering Requirements6.1 WEATHERING RESISTANCE: Two weathering test procedures are specifi ed below. Test data may not be avail-able for the desired color and gloss specifi
20、 ed. Performance levels are established using whites and light colors. It is left to the discretion of the specifi er whether to accept Florida data from a similar color or to use UV-A data in lieu of Florida weathering data.6.1.1 Accelerated Weathering: Accelerated weathering shall be performed in
21、accordance with ASTM D 4587, Cycle 2. Test panels shall have a primer/intermediate coat as recom-mended by the manufacturer.6.1.2 South Florida Weathering: South Florida weath-ering shall be performed in accordance with ASTM D 1014 (45 degrees south exposure, washed with mild detergent). Test panels
22、 shall have a primer/intermediate coat as recommended by the manufacturer.6.1.3 Application shall be according to manufacturers written recommendations. A minimum of three panels shall be exposed. Clear coatings must be tested over the intended basecoat. Initially, and at the end of each level perio
23、d, 60 degree gloss shall be measured according to ASTM D 523 and tristimulus color shall be measured according to ASTM D 2244. Table 3 summarizes the tests of Section 6 as well as the minimum acceptance criteria.6.2 Performance Levels: Tables 1 and 2 specify the amount of time the coating must perfo
24、rm before noticeable change in order to achieve the defi ned performance level. Polyurethane topcoats are available in a wide range of color and gloss. Procurement documents shall state the desired level of performance, exposure method (in accordance with Tables 1 and 2), color, and gloss. For examp
25、le, a specifi er may require Level 2 Florida exposure, initial gloss greater than 80, matched to a specifi c color. A certain level of accelerated weathering does not necessarily correspond to a particular level of atmospheric weathering and they need to be specifi ed independently. These are two in
26、dependent complementary 2American National Standards Institute, 1819 L Street, NW, Suite 600, Washington, DC 20036. Standards available online from www.ansi.org.3American Association of State Highway and Transportation Offi cials, 444 North Capitol Street, NW, Suite 249, Washington DC 20001, 202-624
27、-5800. (http:/www.transportation.org/aashto/home.nsf)SSPC-Paint 36April 1, 20063TABLE 2FLORIDA EXPOSUREMonths to Noticeable ChangeLevel 1 12 to 23Level 2 24 to 47Level 3 48 or more Noticeable change following Florida Exposure testing is defi ned as a gloss reduction of 35% or more of the initial glo
28、ss value measured at a 60 angle or a color change greater than 2.0 E* C.I.E. 1976 L*A*B* (see Section 6.1.2 and Note 11.2).TABLE 1TIME CORRESPONDING TO EACH PERFORMANCE LEVELAccelerated UV-A/Condensation Hours to Noticeable Change Cycles to Noticeable ChangeLevel 1 500 to 999 63 to 125Level 2 1000 t
29、o 1999 126 to 250 Level 3 2000 or more 251 or more Noticeable change following Accelerated UV-A/Condensation testing is defi ned as a gloss reduction of 25% or more of the initial gloss value measured at a 60 angle or a color change greater than 2.0 E* C.I.E.1976 L*A*B* (see Section 6.1.1 and Note 1
30、1.2). TABLE 3PERFORMANCE TESTING RESULTS TO BE REPORTEDExposureTestPerformance Level Exposure Time Measurement Test/Minimum CriteriaColor Change ASTM D 2244Maximum Gloss Reduction ASTM D 523Accelerated Weathering ASTM D 4587Level 1 500 hColor Change less than 2.0 E* C.I.E. 1976 L*A*B*25% from origin
31、al readingLevel 2 1000 hLevel 3 2000 hSouth Florida WeatheringASTM D 1014Level 1 12 moColor Change less than 2.0 E C.I.E. 1976 L*A*B*35% from original readingLevel 2 24 moLevel 3 48 mo Smaller values of color change (less than 2.0 E*) may be visible to the eye, but the noticeable change maximum of 2
32、.0 E* C.I.E. 1976 L*A*B* specifi ed herein is deemed acceptable for most industrial and marine applications. More stringent gloss and color retention require-ments may be specifi ed as needed (see Note 11.2). SSPC-Paint 36April 1, 20064tests for measuring coating performance. If no level is speci-fi
33、 ed, Level 3 will be assumed.47. Material Quality Assurance7.1 Tests may be used to determine the acceptability of a lot or batch of a qualifi ed coating (see Note 10.3.)8. Labeling 8.1 Labeling shall conform to ANSI Z129.1.8.2 Technical data shall be provided for at least all data elements categori
34、zed as “essential” in SSPC-Guide 13. The specifi er may require additional data to satisfy quality assur-ance or local regulatory requirements.9. Disclaimer9.1 While every precaution is taken to ensure that all infor-mation furnished in SSPC standards and specifi cations is as accurate, complete, an
35、d useful as possible, SSPC cannot assume responsibility nor incur any obligation resulting from the use of any materials, coatings, or methods specifi ed herein, or of the specifi cation or standard itself.9.2 This specifi cation does not attempt to address problems concerning safety associated with
36、 its use. The user of this specifi cation, as well as the user of all products or practices described herein, is responsible for instituting appropriate health and safety practices and for insuring compliance with all governmental regulations.10. NotesNotes are not requirements of this specifi catio
37、n.10.1 VOC CONTENT: Each coating, after recommended thinning, must conform to published government regulations regarding volatile organic compound (VOC) content. VOC information should be supplied on the label or the technical data sheet. Various governmental agencies may have different VOC limits o
38、r use different methods of testing. The owner may modify this specifi cation as necessary to specify a particular VOC content limit consistent with local regulations. Coatings meeting the composition and performance requirements of this specifi cation usually have a VOC level less than 420 g/L (3.5
39、lb/gal).10.2 Test results for color and gloss of deeper colors can be expected to vary signifi cantly due to differences in pigment weathering properties. If a dark color is specifi ed, the user is cautioned to verify that color and gloss retention meet specifi -cation requirements for the desired l
40、evel of performance. The coating manufacturer should be contacted if the user desires a higher degree of color stability (less than 2.0 E* C.I.E.1976 L*A*B*) for a specifi c application. Choice of color (including metallics) outside the range of this specifi cation may require consideration of addit
41、ional procedures (such as clear coating) to meet the requirements of Section 6.2.10.3 QUALITY ASSURANCE TESTS: The quality assur-ance tests are used to determine whether the supplied products are of the same type and quality as those originally tested. The selected tests should accurately and rapidl
42、y measure the physical and chemical characteristics of the coating necessary to verify that the supplied material is substantially the same as the previously accepted material. All of the quality assurance tests must be performed on the originally submitted qualifi cation sample. The results of thes
43、e tests are used to establish pass/fail criteria for quality assurance testing of supplied products.10.3.1 Establishing Quality Assurance Acceptance Criteria: Many ASTM test methods contain precision and bias statements. Specifi cation developers should be cognizant of the fact that these statements
44、 exist. Quality assurance test criteria should not be more stringent than the interlaboratory precision of the test methods used. Where precision and bias data are not available for a given test method, determine the standard deviation of a minimum of fi ve measurements taken on the originally teste
45、d and certifi ed material. The pass/fail criterion is that the measurement of the test sample shall fall within two standard deviations of the target value. The contracting parties must agree on a target value.10.3.2 Quality Assurance Testing Procedures: Quality assurance tests include but are not l
46、imited to: infrared analysis (ASTM D 2621), viscosity (ASTM D 562), weight per gallon (ASTM D 1475), total solids (ASTM D 2369), dry time (ASTM D 1640), percent pigment (ASTM D 2371), gloss (ASTM D 523), color (ASTM D 1535), and odor (ASTM D 1296), and AASHTO procedure TP 67.10.4 The procurement doc
47、uments should establish the responsibility for samples, testing, and any required affi davit certifying full compliance with the specifi cation.4Note: Maximum gloss reduction values shown in Table 1 (25%) and Table 2 (35%) are specifi c for these different test methods (see Section 6.1). The maximum
48、 allowable gloss reduction and color change values for Accelerated UV-A/Condensation and Florida Exposure were derived from experience provided by resin and coating manufacturers, end-users, and coating specifi cation engineers who have actively participated on the SSPC Polyurethane Coatings Committ
49、ee.SSPC-Paint 36April 1, 20065Appendix: Optional Laboratory Physical Tests of Applied FilmsTypical properties that might be expected of a quality poly-urethane topcoat are described in Table 4 with corresponding ASTM test methods and suggested test requirements.ANNEX: METHOD FOR DETERMININGISOCYANATE CONTENT (AASHTO TP 67)5A1. SCOPE A1.1This method is designed for the determination of the isocyanate content of the resin system found in polyurethane paints. The reported isocyanate content is based upon 100% resin solids.2. APPARATUS AND MATERIALSA2.1 Analytical balanc
