1、Designation: D 2354 10Standard Test Method forMinimum Film Formation Temperature (MFFT) of EmulsionVehicles1This standard is issued under the fixed designation D 2354; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of las
2、t 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 covers the determination of the mini-mum temperature at which emulsion vehicles coalesce to formcontinuo
3、us films. The term “emulsion” in this test methodincludes latex vehicles.1.2 This test method is limited to emulsions having mini-mum film formation temperatures below 90C.1.3 The values stated in inch-pound units are to be regardedas standard. The values given in parentheses are mathematicalconvers
4、ions to SI units that are provided for information onlyand are not considered standard.1.4 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. Summary of Test Method2.1 In this test method the minimum film formation tem-perature (MFFT) is determined by visual observation ofcracking or whitening in films that have dried over a substratehaving a controlled temperature
6、 gradient.3. Significance and Use3.1 The satisfactory film integrity of emulsion coatingsrequires that as the aqueous phase evaporates the resinousportion of the vehicle coalesces into a continuous film. Lowtemperature impairs the fluidity of the resin particle andthereby their ability to coalesce.
7、Vehicles that can withstandlow temperatures are therefore required, and MFFT is animportant quality feature of emulsion vehicles.4. Apparatus4.1 Minimum Film Formation Temperature BarAn MFFTunit2such as is illustrated in Fig. 1. The bar represented in Fig.1 is designed to be used with thermocouples.
8、 The thermo-couple leads used with the assembly are iron-constantan withan external resistance of 10 V. Also included is a pyrometer(not shown in Fig. 1).NOTE 1Thermometers can be used as an alternative way of measuringtemperature.3It is noted that larger holes (532 in.) (4 mm) will have to bedrille
9、d in the bar to accommodate the thermometers. If thermometers areselected, all holes are drilled on the same side of the bar, as opposed to thesystem of alternate placement of holes when using thermocouples.NOTE 2Aself-contained unit eliminating the need for any accessories,such as for sub-ambient c
10、ooling or temperature measurement, andrequiring only an electrical outlet, piped water, and an air or nitrogensupply has been developed by ICI Paints Division.41This test method is under the jurisdiction of ASTM Committee D01 on Paintand Related Coatings, Materials, and Applications and is the direc
11、t responsibility ofSubcommittee D01.33 on Polymers and Resins.Current edition approved July 1, 2010. Published July 2010. Originally approvedin 1965. Last previous edition approved in 1998 as D2354 - 98 which waswithdrawn March 2007 and reinstated in July 2010. DOI: 10.1520/D2354-10.2The sole source
12、 of supply of the MFFT bar, Model CS 188, known to thecommittee at this time is Dek-Tron Scientific, Custom Scientific Instruments Inc.,244 East 3rd Street, Plainfield, NJ 07060. If you are aware of alternative suppliers,please provide this information to ASTM International. Your comments will recei
13、vecareful consideration at a meeting of the responsible technical committee,1whichyou may attend.3The sole source of supply of the thermometer, Prince No. A-011044 known tothe committee at this time is Princo Instruments Inc., 1020 Industrial Hwy.,Southampton, PA 18966. If you are aware of alternati
14、ve suppliers, please providethis information to ASTM International. Your comments will receive carefulconsideration at a meeting of the responsible technical committee,1which you mayattend.4The sole source of supply of the MFFTBAR units, Models MFFT-60, andMFFT-90, known to the committee at this tim
15、e is Rhopoint Instrumentation Ltd.,Beeching Rd., Bexhill-on-Sea, East Sussex, TN39 3LG, England. For the name ofa local distributor, telephone them at 011441424214291. Interested parties areinvited to submit information regarding the identification of acceptable alternativesto the Committee on Stand
16、ards, ASTM International. Your comments will receivecareful consideration at a meeting of the responsible technical committee,1whichyou may attend.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.4.2 Dry Air or Dry Nitrogen Supply, wi
17、th a regulating valveand flow meter.4.3 Film Caster, having a 6-mil (150-m) clearance.5. Reagents and Materials5.1 Dry Ice.5.2 Isopropanol, anhydrous.6. Procedure6.1 Set up the MFFT bar in a level position with the lowertemperature leg of the bar immersed in a dry ice-isopropanolbath. It is importan
18、t that the surface of the bar be smooth andplane to ensure uniform film thicknesses. Use a12-gal (2-L)container for this purpose. (The container can be insulated withany suitable material to reduce heat loss.) Adjust the height ofthe dry ice-isopropanol bath as needed to bring the temperatureof the
19、bar to approximately 0C at the lowest temperature-measuring stage of the unit. Lower or higher temperatures canbe obtained, if needed, by adjusting the bath height. The bathheight needed to obtain 0C will vary depending on the heatconductivity of the metal used in the construction of the bar.Expose
20、the higher temperature end of the bar at approximately25C by either conducting the test in a constant-temperatureroom at this temperature or by thermostatting the leg.6.2 Immediately after imposing the temperature gradient onthe bar, place the cover over it and adjust the flow of dry air (ornitrogen
21、) at a rate of 4 L/min from the low-temperature end tothe high-temperature end of the bar. Allowing the air to retainmoisture by warming up prevents water condensation at thecold temperature end that would interfere with film drying.Approximately 45 min is needed for the temperature gradientto reach
22、 equilibrium once the bar is placed in operation. The airmanifold holes must be clean and free of frost before startinga test.NOTE 3A mixture of ethylene glycol and surfactant applied to the airoutlet alleviates the frosting condition temporarily.6.3 Once a constant-temperature gradient is establish
23、ed,remove the cover and cast the films using the 3-mil (75 m)applicator (Note 3). Cast films from the low to the high-temperature end of the bar because the extension at thehigh-temperature end is designed to permit overflow to fall intoa container below the bar. After the film is cast and the cover
24、put in place, approximately 1 to 2 h are required for the film todry. Check the air flow and isopropanol bath height before anytests are started and then maintain them at their respectivelevels until the test is completed.NOTE 4If desired, a12-mil (13-m) polyethylene terephthalate sheetof 5-in. (125
25、-mm) width can be placed on the bar surface before castingthe film. Tests show that there are no differences between minimumfilming temperatures determined with and without the sheet. The polyeth-ylene terephthalate film permits not only easier clean-up of the apparatus,but also a semi-permanent rec
26、ord of the test. Special care must beexercised to ensure good contact of the sheet with the bar.Accomplish thisby either of the following techniques:(1) Wipe the sheet with a dry cloth to develop a static charge beforeplacement on the bar.(2) Coat the sheet with silicone oil before placement on the
27、bar.NOTE 11 in. = 25.4 mm.FIG. 1 Minimum Film Formation Temperature BarD23541026.4 After the film has dried, observe for discontinuity asevidenced by whitening or cracking or both. Record the lowesttemperature on the bar at which the film is still continuous asthe minimum film formation temperature.
28、7. Report7.1 Report the following information:7.1.1 MFFT in degrees Celsius, and7.1.2 Description of the discontinuity indicating degree ofwhitening and cracking.8. Precision and Bias8.1 PrecisionInformation for a formal precision statementhas not yet been obtained, but it is reported that MFFT valu
29、esobtained by this test method can be expected to fall within62C of their mean.8.2 BiasNo information can be presented on the bias ofthe procedure of this test method, because no material havingan accepted reference value is available.9. Keywords9.1 emulsion vehicles; film formation; minimum film fo
30、r-mation temperature; MFFTASTM 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 patent rights, and the riskof infrin
31、gement of such rights, are entirely their own responsibility.This standard is subject to revision at any time by the responsible technical committee and must be reviewed every five years andif not revised, either reapproved or withdrawn. Your comments are invited either for revision of this standard
32、 or for additional standardsand should be addressed to ASTM International Headquarters. Your comments will receive careful consideration at a meeting of theresponsible technical committee, which you may attend. If you feel that your comments have not received a fair hearing you shouldmake your views
33、 known to the ASTM Committee on Standards, at the address shown below.This standard is copyrighted by ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959,United States. Individual reprints (single or multiple copies) of this standard may be obtained by contacting ASTM at the aboveaddress or at 610-832-9585 (phone), 610-832-9555 (fax), or serviceastm.org (e-mail); or through the ASTM website(www.astm.org). Permission rights to photocopy the standard may also be secured from the ASTM website (www.astm.org/COPYRIGHT/).D2354103
