1、Designation: F2468 05 (Reapproved 2011)Standard Classification forSpecifying Silicone Adhesives and Sealants forTransportation Applications1This standard is issued under the fixed designation F2468; the number immediately following the designation indicates the year oforiginal adoption or, in the ca
2、se 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 classification covers silicone adhesives and seal-ants intended for but not limited t
3、o sealing and retainingmetallic and nonmetallic component assemblies in transporta-tion applications. The materials cure to an elastomeric state bytheir specified cure system and mechanism.NOTE 1The classification system may serve many of the needs ofindustries using silicone materials. This classif
4、ication is subject torevision, as the need requires; therefore, the latest revision should alwaysbe used.1.2 This classification is intended to be a means of classi-fying silicone materials. It is not intended for engineeringdesign purposes.1.3 It is not the intent of this classification to includep
5、ressure-sensitive or hot-melt adhesives.1.4 In all cases in which the provisions of this classificationsystem would conflict with the referenced ASTM standard fora particular method, the latter shall take precedence.1.5 The values stated in SI units are to be regarded asstandard. No other units of m
6、easurement are included in thisstandard.1.6 The following safety hazards caveat pertains only to thetest methods portion, Section 7, of this classification. Thisstandard does not purport to address all of the safety concerns,if any, associated with its use. It is the responsibility of the userof thi
7、s standard to establish appropriate safety and healthpractices and determine the applicability of regulatory limita-tions prior to use.2. Referenced Documents2.1 ASTM Standards:2C679 Test Method for Tack-Free Time of ElastomericSealantsD149 Test Method for Dielectric Breakdown Voltage andDielectric
8、Strength of Solid Electrical Insulating Materialsat Commercial Power FrequenciesD150 Test Methods for AC Loss Characteristics and Per-mittivity (Dielectric Constant) of Solid Electrical Insula-tionD257 Test Methods for DC Resistance or Conductance ofInsulating MaterialsD412 Test Methods for Vulcaniz
9、ed Rubber and Thermo-plastic ElastomersTensionD471 Test Method for Rubber PropertyEffect of LiquidsD573 Test Method for RubberDeterioration in an AirOvenD618 Practice for Conditioning Plastics for TestingD624 Test Method for Tear Strength of Conventional Vul-canized Rubber and Thermoplastic Elastome
10、rsD792 Test Methods for Density and Specific Gravity (Rela-tive Density) of Plastics by DisplacementD907 Terminology of AdhesivesD1002 Test Method for Apparent Shear Strength of Single-Lap-Joint Adhesively Bonded Metal Specimens by Ten-sion Loading (Metal-to-Metal)D1053 Test Methods for Rubber Prope
11、rtyStiffening atLow Temperatures: Flexible Polymers and Coated FabricsD1084 Test Methods for Viscosity of AdhesivesD1349 Practice for RubberStandard Temperatures forTestingD1415 Test Method for Rubber PropertyInternationalHardnessD1566 Terminology Relating to RubberD1898 Practice for Sampling of Pla
12、stics3D2240 Test Method for Rubber PropertyDurometerHardnessD3182 Practice for RubberMaterials, Equipment, andProcedures for Mixing Standard Compounds and Prepar-ing Standard Vulcanized SheetsD4800 Guide for Classifying and Specifying Adhesives2.2 SAE Standard:4SAE J369 Flammability of Polymeric Int
13、erior Materials1This classification is under the jurisdiction of ASTM Committee F03 onGaskets and is the direct responsibility of Subcommittee F03.30 on Classification.Current edition approved May 1, 2011. Published July 2011. Originally approvedin 2005. Last previous edition approved in 2005 as F24
14、68 05. DOI: 10.1520/F2468-05R11.2For referenced 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.3Withdrawn. The last approved
15、 version of this historical standard is referencedon www.astm.org.4Available from SAE International (SAE), 400 Commonwealth Dr., Warrendale,PA 15096-0001, http:/www.sae.org.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.Horizontal T
16、est Method2.3 UL Standard:5UL 94 Flammability3. Terminology3.1 DefinitionsSome terms in this classification are de-fined in Terminiologies D907 and D1566.3.2 Definitions of Terms Specific to This Standard:3.2.1 cure mechanismthe method of initiating the cure fora silicone material.3.2.2 cure systemt
17、he cross-linking mechanism the sili-cone material uses to transition to the elastomeric state.3.2.3 draw-downa method of sample preparation of vis-cous and sag-resistant sealants, in which the sealant is leveledusing a knife or tool to a specified thickness.3.2.4 formed in place gasket, fipga one- o
18、r two-component adhesive or sealant applied wet, uncured, to a jointsurface where the mating parts are assembled before the curingprocess is complete. When fully cured it forms a barrier tomedia migration across the joint.3.2.5 sag resistancea property of some adhesives andsealants that enables the
19、applied or extruded material to retainits shape before curing or cross-linking.3.2.6 thixotropica rheological property of uncured seal-ants in which the sealant resists sagging or slumping unlessdisturbed by an external force or pressure.3.2.7 transportationany transportation venue involvingland, se
20、a, or air, civilian or military, stationary and smallengines.3.2.8 volatileslow molecular weight components of anadhesive or sealant that can be extracted by the environment ofthe application.4. Significance and Use4.1 The purpose of this classification system is to provide amethod of adequately ide
21、ntifying silicone adhesives and seal-ants through the use of a line call-out designation.4.2 This classification system was designed to permit theaddition of property values for future silicone adhesives andsealants.5. Classification5.1 A ten-digit numbering system is used to classify asilicone adhe
22、sive and sealant cure system, cure mechanism,application rate, tack free time; ultimate elongation, tensilestrength; blowout resistance, lap shear bond strength, specificgravity, and silicone volatile content as defined in Table 1. Thefirst column (left side of the table) indicates the digit number
23、ororder sequence required while the designation numbers foreach property are indicated on the top of the table. The ten-digitclassification number must also be separated with hyphensbetween the fourth and fifth digit, and the sixth and seventhdigit as seen in Example 1 (5.1.1).5.1.1 Example 1To spec
24、ify a silicone adhesive or sealantwith an acetoxy cure system, two-part moisture cure mecha-nism, application rate of 150 g/min, tack free time of 8 min,400 % ultimate elongation, 1.2 MPa tensile strength, 15 sblowout resistance, 1.1 specific gravity, 2.0 MPa lap shearbond strength, and 2.5 % silico
25、ne volatile, the line call-outwould be:ASTM F2468, 2232244224545Available from Underwriters Laboratories (UL), 333 Pfingsten Rd., North-brook, IL 60062-2096, http:/.TABLE 1 Minimum Classification RequirementsSelectionOrderSequenceProperty Designation12 3 4 5 6 7891stDigit Cure system(Cure by-product
26、)Addition(no by-product)Acetoxy(aceticacid)Alkoxy(methanol,ethanol)Amine(cyclo-hexylamine)Enoxy(acetone)Oxime(methyl ethylketoxime)Freeradical. Asspecified2ndDigit Cure mechanism One-partmoisturecureTwo-partmoisturecureOne-partradiationcureAOne-partradiation-moisturecureOne-partthermalcureTwo-partth
27、ermalcureRadiation . Asspecified3rdDigit Application rate, g/min 999 Asspecified4thDigit Test Method C679,Tack free time, min60 Asspecified5thDigit Test Methods D412 (Die C)Ultimate elongation, %999 . Asspecified6thDigit Test Methods D412,Tensile strength, MPa14 Asspecified7thDigit Blowout resistanc
28、e,Bs 60 . Asspecified8thDigit Test Methods D792,Specific gravity, g/cc1.5 Asspecified9thDigit Test Method D1002,CLap shear bondstrength, MPa14 Asspecified10thDigit Silicone volatileContent, %10 AsspecifiedAUltraviolet light (UV), microwave, or visible light cure.BResistance to blowout refers to the
29、time to failure at a standardized internal pressure using a fixture as agreed upon between producer and user.CStandard test conditions: 5 cm (1.97 in.)/min cross head speed, 1 mm (0.039 in.) gap, 1.27 cm (0.50 in.) overlap, Q panel 20204T3 Aluminum (as received).F2468 05 (2011)2where:2 = the acetoxy
30、 cure system,2 = the two-part moisture cure,3 = application rate between 100 and 199 g/min,2 = tack free time between 5 and 9.9 min,4 = ultimate elongation between 300 and 499 %,4 = tensile strength between 1.036 and 1.380 MPa,2 = blowout resistance between 10 and 20 s,4 = specific gravity between 1
31、.06 and 1.15 g/cc,5 = lap shear strength between 1.381 and 3.45 MPa, and4 = silicone volatile content between 2.0 and 2.9 %.6. Line Call-Outs6.1 A “line call-out,” which is a specification, shall containthe ASTM classification number F2468, a ten-digit prefixspecifying the cure system, cure mechanis
32、m, application rate,tack free time, ultimate elongation, tensile strength, blowoutresistance, specific gravity, lap shear bond strength, and sili-cone volatile content. This shall be followed by appropriatesuffixes per Section 12 as agreed upon between producer anduser.7. General Requirements7.1 Gen
33、eral requirements are properties that are inherent inevery lot of silicone produced but may be tested in accordancewith the line call-out at a frequency agreed on by the producerand user to verify specification conformance.7.2 SuffxesWhen using the line call-out for materialscovered by this classifi
34、cation, the suffixes found in Table 2shall be used to detail specific requirements needed for theapplication intended and as agreed upon between producer anduser. In general, the suffix letter gives the test condition and thesecond digit gives the specific requirement.TABLE 2 Suffix Symbols and Requ
35、irementsSymbol CharacteristicA HEAT RESISTANCETest Method D573First digitSee Table 3 for time designation.Second digitSee Table 3 for temperature designation.Third digitSee Table 4 for hardness change designation.Fourth digitSee Table 4 for tensile change designation.Fifth digitSee Table 4 for elong
36、ation change designation.Sixth digitSee Table 4 for volume change designation.C CORROSIVITYSecond letterA = CopperB=SteelC = AluminumThree-digit number001=0=testmethodtobespecified by user.1 = no permanent discoloration of the metals that does not buff off with anonabrasive cloth.D ELECTRICAL (diele
37、ctric/resistance properties)Second letterA = dielectric strength (short time), Test Method D149Three-digit number x factor of 0.1 = kV/mm, minB = dielectric strength (step by step), Test Method D149Three-digit number x factor of 0.1 = kV/mm, minC = insulation resistance, Test Methods D257Three-digit
38、 number x factor of 106= V,minD = dielectric constant at 1 MHz, Test Methods D150, maxThree-digit number x factor of 0.1 = valueE = dissipation factor at 1 MHz, Test Methods D150, maxThree-digit number x factor of 0.0001 = valueTABLE 2 ContinuedSymbol CharacteristicE FLUID RESISTANCETest Method D471
39、Second letterA = ASTM #1 OilB = IRM 902 OilC = IRM 903 OilD = ASTM SF105E = ASTM B FuelF = ASTM C FuelQ = as specifiedFirst digitSee Table 3 for time designation.Second digitSee Table 3 for temperature designation.Third digitSee Table 4 for hardness change designation.Fourth digitSee Table 4 for ten
40、sile change designation.Fifth digitSee Table 4 for elongation change designation.Sixth digitSee Table 4 for volume change designation.F LOW TEMPERATURETest Methods D1053G TEAR STRENGTHTest Method D624Second letterB = Die “B”C = Die “C”First digitSee Table 3 for time designation.Second digitSee Table
41、 3 for temperature designation.H HARDNESSSecond letterA = Test Method D2240B = Test Method D1415First digitSee Table 3 for time designation.Second digitSee Table 3 for temperature designation.L COLORSecond letterA = does not have to match a standardB = as agreed upon between producer and userM FLAME
42、 RETARDANTSecond letterA=UL 94First digit indicated minimum specimen thickness, mm0 to be specified1 0.252 0.403 0.804 1.605 2.506 3.007 6.008 12.709 12.70Second digit indicates type of flame test1 = vertical (94 V)2 = horizontal (94 H)3 = 125-mm flame (94 to 95 V)4 = vertical thin materials (94 VTM
43、)Third digit indicates the flame rating0 = (94 V/94 VTM) 0 refer to UL 941 = (94 V/94 VTM) 1 refer to UL 942 = (94 V/94 VTM) 2 refer to UL 943 = (94HB) 1 burn rate, 15009 = As specifiedV VISCOSITYSecond letterA = Test Methods D1084, Method B, using an RVT viscometerB = Test Methods D1084, Method B,
44、using an LVT viscometerFirst digit indicates spindle numberFor RVT(A) For LVT(B)0 = As specified 0 = As specified1 = RV spindle #1 1 = LV spindle #12 = RV spindle #2 2 = LV spindle #23 = RV spindle #3 3 = LV spindle #34 = RV spindle #4 4 = LV spindle #45 = RV spindle #56 = RV spindle #67 = RV spindl
45、e #7Second digit indicates spindle speedFor RVT(A) For LVT(B)0 = As specified 0 = As specified1=RV0.5RPM 1=LV0.3RPM2=RV1.0RPM 2=LV0.6RPM3=RV2.0RPM 3=LV1.5RPM4=RV4.0RPM 4=LV3.0RPM5=RV5.0RPM 5=LV6.0RPM6=RV10RPM 6=LV12RPM7=RV20RPM 7=LV30RPM8=RV50RPM 8=LV60RPM9 = RV 100 RPMThird digit indicates viscosit
46、y in centipoise (cP)0 = As specified1=$50 but 100 As specifiedATable 4 indicates a maximum change from an original test value and is not an absolute value.As such, when a “% maximum change” is indicated, this is the plus/minusrange of variation the user would anticipate from the initial value after timed exposure to the temperature or the fluid indicated, or both.F2468 05 (2011)5
