1、Designation: E 28 99 (Reapproved 2004)Standard Test Methods forSoftening Point of Resins Derived from Naval Stores byRing-and-Ball Apparatus1This standard is issued under the fixed designation E 28; the number immediately following the designation indicates the year of originaladoption or, in the ca
2、se of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A superscriptepsilon (e) 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 te
3、st methods are intended for determining thesoftening point of resins (including rosin and terpene resins)and similar materials by means of the ring-and-ball apparatus.NOTE 1For testing asphalts, tars, and pitches, see Test Method D 36.1.1.1 Test method using the manual ring and ball softeningpoint a
4、pparatus, and1.1.2 Test method using an automated ring and ball soften-ing point apparatus.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, ass
5、ociated 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.2. Referenced Documents2.1 ASTM Standards:2D 36 Test Method for Softening Point of Bitumen (Ring-an
6、d-Ball Apparatus)E 1 Specification for ASTM Liquid-in-Glass ThermometersE 177 Practice for Use of Terms Precision and Bias inASTM Test MethodsE 691 Practice for Conducting an Interlaboratory Study toDetermine the Precision of a Test Method3. Significance and Use3.1 In general, with materials of thes
7、e types, softening doesnot take place at a definite temperature. As the temperaturerises, these materials gradually change from brittle or exceed-ingly thick and slow-flowing materials to softer and lessviscous liquids. For this reason, the determination of thesoftening point must be made by a fixed
8、, arbitrary, and closelydefined method if the results obtained are to be comparable.3.2 In these test methods, the softening point is defined asthe temperature at which a disk of the sample held within ahorizontal ring is forced downward a distance of 25.4 mm (1in.) under the weight of a steel ball
9、as the sample is heated at5C/min in a water, glycerin, silicone oil, ethylene glycol/wateror glycerin/water bath.4. Sample Preparation4.1 Preparation of Sample by the Pour Method:4.1.1 This procedure is suitable for materials that can beheated and poured without adverse effects on the softeningpoint
10、.4.1.2 Select a sample representative of the material to betested. The sample should consist of flakes, pastilles, or freshlybroken lumps free of oxidized surfaces. Avoid inclusion offinely divided material or dust.4.1.3 Select a quantity at least twice that necessary to fill thedesired number of ri
11、ngs, and melt it immediately in a cleancontainer, using an oven, hot plate, sand bath or oil bath toprevent local overheating. Take care to avoid incorporating airbubbles in the sample. Melt the sample completely, but do notheat it above a temperature necessary to pour the materialreadily. The time
12、from the beginning of heating to the pouringof the sample should not exceed 15 min.NOTE 2For materials that may be heat sensitive, continuously inertthe flask containing the test specimen with nitrogen (N2) during theremelting procedure.4.1.4 For materials that tend to crack or shrink in the ring on
13、cooling, immediately before filling the ring, preheat the ring toapproximately the temperature at which the material is to bepoured. The ring, while being filled, should rest bottom downon a suitable metal surface. Pour the sample into the ring so asto leave an excess on cooling. After cooling a min
14、imum of 30min, trim off the excess resin on the periphery of the ring. Toremove excess resin from the top, cut the excess material offcleanly with a slightly heated knife or spatula, or grasp the ring1These test methods are under the jurisdiction of ASTM Committee D01 onPaint and Related Coatings, M
15、aterials, and Applications and is the direct responsi-bility of Subcommittee D01.34 on Naval Stores.Current edition approved June 1, 2004. Published June 2004. Originallyapproved in 1936. Last previous edition approved in 1999 as E 28 99.2For referenced ASTM standards, visit the ASTM website, www.as
16、tm.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.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.in a pai
17、r of tongs and draw the top surface quickly and firmlyover the surface of a heated metal plate. In case the test isrepeated, use a clean container and fresh sample.4.2 Preparation of Sample by the Molding Method:4.2.1 See Appendix X1, Alternate Sample Preparation Pro-cedures.4.3 Preparation of Sampl
18、es Having a Low Softening Point(up to 35C (95F):4.3.1 Place a ring on a piece of aluminum foil. Pour thematerial to be tested into the ring, then place the foil and filledring on dry ice or in a freezer to cool. The material in the ringmust be free of bubbles.4.3.2 After cooling, cut and scrape off
19、any excess materialusing a slightly heated spatula, then slide the ring gently fromthe foil. Place the ring in the supporting apparatus, andimmediately perform the softening point analysis according toSection 11.5. Reagents and Materials5.1 Bath Liquids:5.1.1 Distilled or Deionized Water, Freshly Bo
20、iledForsoftening points between 35C (95F) and 80C (176F).5.1.1.1 Use distilled or deionized water that has been cooledto at least 27C (81F) below the anticipated softening point,but in no case lower than 5C (41F).5.1.2 USP GlycerinFor softening points between 80C(176F) and 150C (302F). Repeated use
21、of glycerin willincrease the moisture content over time and may affect results.Replace with fresh glycerin if any change in appearance isnoted.NOTE 3Glycerin should not be used for softening points greater than150C (302F) due to the 160C (320F) flash point of glycerin.5.1.3 Silicone Oil (Polydimethy
22、lsiloxane)For softeningpoints above 80C (176F). The silicone oil must have atemperature range of 200C + (392F), remain clear within thetemperature range, have no apparent reactivity with the testspecimen, have a high water repellency, and maintain auniform viscosity and stirring rate within the temp
23、eraturerange.3NOTE 4Replace with fresh silicone oil if any change in appearance isnoted. Do not use silicone oil that contains any gels; gels are an indicatorthat degradation has occurred.5.1.4 Ethylene GlycolFor softening points up to 35C(95F).5.1.4.1 Prepare a fresh 50/50 (v/v) mixture of distille
24、d waterand ethylene glycol prior to sample analysis. For softeningpoints between 0C and 35C, a 50/50 (v/v) mixture of glycerinand water may be used.MANUAL RING AND BALL SOFTENING POINTMETHOD6. Apparatus6.1 Ring and Ball Apparatus, consisting of the following:6.1.1 RingA brass, shouldered ring confor
25、ming to thedimensions shown in Fig. 1(a).6.1.2 BallA steel ball, 9.53 6 0.1 mm (38 in.) in diameter,weighing between 3.45 and 3.55 g.6.1.3 Ball-Centering GuideA brass guide for centeringthe ball conforming to the general shape and dimensions shownin Fig. 1(c), the use of which is optional.6.2 Suppor
26、t for Ring and Thermometer Any convenientmethod for supporting the ring and thermometer may be used,provided it meets the following requirements:6.2.1 The ring must be supported in a substantially horizon-tal position.6.2.2 When using the apparatus shown in Fig. 1(d): Thebottom of the ring must be 2
27、5.4 6 0.2 mm (1.0 in.) above thehorizontal plate below it; the bottom surface of the horizontalplate must be 12.7 to 19.05 mm (0.5 to 0.75 in.) above thebottom of the beaker.6.2.3 Suspend a thermometer so that the bottom of the bulbis level with the bottom of ring and within 12.7 mm (0.5 in.)but not
28、 touching the ring or the ring holder.6.3 BathA heat-resistant glass beaker, at least 85 mm(3.34 in.) in diameter and 127 mm (5 in.) in depth from thebottom of the flare, for example, an 800-mL low-form Griffinbeaker.6.4 Temperature Measuring DeviceA thermometer hav-ing a range described below and c
29、onforming to the require-ments prescribed in Specification E 1, or an electronic tem-perature measuring device, such as a resistance thermometer orthermocouple. The device must exhibit the same temperatureresponse as the thermometers specified in Specification E 1 andmust be accurately calibrated.6.
30、4.1 An ASTM Thermometer, having a range from 38to+50C (36 to +120F), ASTM 5C, 5F, or equivalent.6.4.2 An ASTM Low-Softening-Point Thermometer, havinga range from 2 to 80C (30 to 180F), ASTM 15C, 15F orequivalent.6.4.3 An ASTM Medium-Softening Point Thermometer,having a range from 30 to 200C (85 to 3
31、92F), ASTM 16C,16F or equivalent.6.4.4 An ASTM High-Softening-Point Thermometer, hav-ing a range from 2 to 300C (30 to 580F), ASTM 7C, 7F orequivalent.6.5 StirrerThe heating bath must be stirred at a speedsufficient to ensure uniform heat distribution without causingsignificant sideways displacement
32、 of the resin as it softens inthe ring. A stirring rate of 500 to 700 r/min is typical. Amechanical motor-driven stirrer, mounted so that any vibra-tions created by its rotation are not conveyed directly to thesample support, or a magnetic stirrer placed under the bath maybe used.6.6 Heat SourceA he
33、at source capable of maintaining theproper heating rate, such as a temperature controller withimmersion heating coil, an electric heater or a bunsen burner.3The sole source of supply of silicone oil, 200 fluid, 50 cSt viscosity known tothe committee at this time is Dow Corning Corp., Midland, MI 486
34、86. If you areaware of alternative suppliers, please provide this information to ASTM Interna-tional Headquarters. Your comments will receive careful consideration at a meetingof the responsible technical committee,1which you may attend.E 28 99 (2004)27. Procedure for Materials Having a Softening Po
35、intBetween 35 and 80C (95 and 176F)7.1 Assembly of ApparatusFill the bath with distilled ordeionized water, conforming to the requirements in 5.1.1, sothat the level will be 105 6 3 mm (4.13 6 0.12 in.). If amechanical motor-driven stirrer is used, position the axis of thestirrer shaft near the back
36、 wall of the beaker, with the bladesclearing the wall and with the bottom of the blades approxi-mately 19.0 mm (0.75 in.) above the top of the ring. If theball-centering guide is not used, make a slight indentation inthe center of the sample by pressing the ball or a rounded rod,slightly heated for
37、hard materials, into the material at this point.Suspend the ring containing the sample in the water in themanner described in 6.2.2 or 25.4 6 0.2 mm (1 in.) above thebottom of the beaker when using the apparatus in Fig. 2( e).Center the ball on the surface of the test specimen in the ring.Suspend an
38、 ASTM low-softening-point thermometer in thebath as prescribed in 6.2.3. Maintain the initial temperature ofthe water for 15 min. Start stirring, and continue stirring untilcompletion of the determination.7.2 HeatingHeat the bath so that the temperature of thewater is raised uniformly at a rate of 5
39、C (10F)/min. Protectthe bath from drafts, using shields if necessary. Do not averagethe rate of rise over the test period. The maximum permissiblevariation for any 1-min period after the first three minutes is60.5C (61F). Reject any test in which the rate of tempera-ture rise does not fall within th
40、ese limits.NOTE 5Rigid adherence to the prescribed rate of heating is absolutelyessential for reproducibility of results.7.3 Softening PointRecord as the softening point thetemperature of the thermometer at the instant the materialtouches the lower horizontal plate (Fig. 1(d). Make nocorrection for
41、the emergent stem of the thermometer.NOTE 6When the ball drops through the ring, it should be completelysurrounded by softening resin and should drop straight down to the lowerhorizontal plate.7.4 Thoroughly clean the ring holder, ball, and ring in asuitable solvent.FIG. 1 Shouldered Ring, Ring Hold
42、er, Ball-Centering Guide, and Assembly of Apparatus Showing Two RingsE 28 99 (2004)38. Calibration8.1 A calibration check of any temperature controllers usedin the manual ring and ball softening point apparatus must beperformed on a regular basis since accurate temperature controlis required.9. Proc
43、edure for Materials Having Softening PointsBetween 80C (176F) and 150C (302F)9.1 Use the same procedure as described in Section 8,except fill the bath with glycerin or silicone oil (Note 3) anduse an ASTM medium-softening-point thermometer. Themaximum allowable starting temperature of the bath is th
44、elower of: ( a) 27C (81F) below the anticipated softeningpoint, or (b) 32C (90F).NOTE 7For materials softening around 80C (176F) report the bathliquid since a glycerin or silicone oil bath will yield a slightly higher resultthan a water bath.NOTE 8Repeated use of glycerin will increase the moisture
45、contentover time and may affect results. Replace with fresh glycerin if any changein appearance is noted.10. Procedure for Materials Having Softening PointsAbove 150C (302F)10.1 Use the same procedure as described in Section 9,except fill the bath with silicone oil (Note 4) and use an ASTMhigh-softe
46、ning-point thermometer.11. Procedure for Materials Having Softening PointsBelow 35C (95F)11.1 Apparatus:11.1.1 Isopropyl Alcohol Dry-Ice Bath.11.2 Procedure:11.2.1 Cool the bath, described in 5.1.4.1, to 25C (13F)in an isopropyl alcohol dry-ice bath.11.2.2 Use the same procedure as in Section 9 exce
47、pt for thebath liquid, and immediately begin heating as directed once thetest specimen in the ring has been placed in the bath.AUTOMATED RING AND BALL SOFTENING POINTMETHOD12. Apparatus12.1 Automated Ring and Ball-Softening Point Instrumentwith Control Unit, test units, and test inserts.12.2 RingA b
48、rass, shouldered ring conforming to thedimensions shown in Fig. 1(a).12.3 BallA steel ball, 9.53 6 0.1 mm (38 in.) in diameter,weighing between 3.45 and 3.55 g.12.4 Beaker, 600 mL. Ensure that the dimensions willproperly fit the heating unit.12.5 Stir BarThe dimensions must be such that the barspins
49、 freely under the test stand.FIG. 2 Assembly of Apparatus Showing Stirrer and Single Shouldered RingE 28 99 (2004)413. Procedure for Materials Having a Softening PointBetween 35C (95F) and 80C (176F)13.1 Add a stir bar to the 600-mL beaker and fill withapproximately 500 mL of distilled or deionized water, con-forming to the requirements in 5.1.1. Ensure that the beaker isproperly positioned on the heater in the test unit. Place theprepared sample rings in the test insert. Place the ba
