ASTM_D_1644_-_01_2012.pdf

Designation:D164401(Reapproved 2012)Standard Test Methods forNonvolatile Content of Varnishes1This standard is issued under the fixed designation D1644;the number immediately following the designation indicates the year oforiginal adoption 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.This standard has been approved for use by agencies of the Department of Defense.1.Scope1.1 These test methods determine the fraction of a varnishthat is nonvolatile at the temperature of the test while volatilesolvents are driven off.It is sometimes an approximatemeasure of the film-forming matter in a varnish.1.2 The values stated in SI units are to be regarded as thestandard.The values given in parentheses are for informationonly.1.3 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 and determine the applica-bility of regulatory limitations prior to use.For a specificstatement,see Section 3.2.Significance and Use2.1 These test methods are applicable to varnish and areuseful to producers and users in determining nonvolatilecontent and are sometimes an appropriate measure of thefilm-forming matter in varnish.3.Hazards3.1 Since the flash points of some of the solvents used incoatings and related products are below the temperature of thetest,care should be exercised that the lower explosive limits ofthe solvents are not exceeded.The amount of solvent in theoven atmosphere at any one time will depend on the number oftests(pans)in the oven,the percent nonvolatile of the samples,the size of the oven,the type of oven(mechanical or gravityconvection)and the air changes per hour.TEST METHOD A3 h AT 105C4.Procedure4.1 Place a portion of the thoroughly mixed sample in astoppered bottle,or alternatively,in a weighing pipet or a10-mL syringe without a needle,and from this weigh bydifference 1.2 6 0.1 g into a tared flat-bottomed metal or glassdish(Note 1),80 to 100 mm in diameter and 5 to 10 mm indepth,such as friction-top can covers,ointment boxes,or petridishes.NOTE1The term“tared,flat-bottomed dish”implies that the emptydish has no measurable weight change when subjected to the same heatschedule as prescribed for the dish containing the specimen.If this isfound to be not so,then more suitable vessels must be found,orcorrections applied.4.2 By gentle tilting,spread the specimen over the bottom ofthe dish and heat for 3 h in a ventilated oven maintained at 1056 2C.If necessary,a piece of stout wire can be included in thetare of the dish and used at intervals to break up skins bystirring during the heating period.Cool in a desiccator andweigh the dish.5.Calculation5.1 Calculate the percent of nonvolatile matter NV asfollows(Note 2):NV5C 2 A!/S#3100(1)where:A=weight of dish,g,S=weight of specimen used,g,andC=weight of dish and contents after heating,g.NOTE2Determinations of nonvolatile matter by this test method maygive high results due either to incomplete elimination of volatile matter orto absorption of oxygen by oxidizing-type varnishes.6.Report6.1 Report the nonvolatile matter of the sample to thenearest 0.1%.TEST METHOD B10 min at 150C7.Apparatus7.1 Sample Transfer Device,a 2 or 5-mL Luer syringe.7.2 Solids Dish,made from metal foil of such design as toensure reasonably good contact of the bottom surface whenplaced on the hot plate.Condition the dish for at least 10 minat 150C or higher;then store in a desiccator.1These test methods are under the jurisdiction of ASTM Committee D01 onPaint and Related Coatings,Materials,and Applications and are the directresponsibility of Subcommittee D01.21 on Chemical Analysis of Paints and PaintMaterials.Current edition approved June 1,2012.Published July 2012.Originally approvedin 1959.Last previous edition approved in 2006 as D1644 01(2006).DOI:10.1520/D1644-01R12.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 7.3 Hot-Plate,capable of maintaining a surface temperatureof 150 6 3.5C(302 6 6F).8.Procedure8.1 Weigh by difference from the syringe into a tared solidsdish,sufficient sample to form a 65 to 125m(2.5 to 5.0mil)thick nonvolatile residue.Use a minimum of toluene todistribute the specimen,by gentle swirling uniformly,over thebottom of the dish.NOTE3Specimen size limits may be estimated from the followingtable,which was calculated for a material having nonvolatile matter witha specific gravity of 1.3:Weight of Nonvolatile ResidueDiameter of Dish45 mm100 mmFor a 2.5-mil varnish film0.12 g0.60 gFor a 5-mil varnish film0.25 g1.20 g8.2 Place the dish on the hot plate at 150 6 3.5C for 10min.Cool to room temperature in a desiccator,then reweigh.9.Calculation9.1 Calculate the nonvolatile matter as described in Section5.10.Repor