1、Designation: D3642 98 (Reapproved 2010)D3642 13Standard Test Method forSoftening Point of Certain Alkali-Soluble Resins1This standard is issued under the fixed designation D3642; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the
2、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 test method covers the determination of the softening point of certain alkali-soluble resins having unifo
3、rm plastic flowcharacteristics as the melting point is approached.1.2 The resin manufacturer should specify whether or not this test method may be used for his product(s).1.3 This test method is not suitable for styrene-maleic anhydride resins.NOTE 1For testing rosin and other resins, see Test Metho
4、d E28. For testing asphalts, tars, and pitches, see Test Method D2398.1.4 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibilityof the user of this standard to establish appropriate safety and health practices and determine the
5、 applicability of regulatorylimitations prior to use.2. Referenced Documents2.1 ASTM Standards:2D2398 Test Method for Softening Point of Bitumen in Ethylene Glycol (Ring-and-Ball) (Withdrawn 1984)3E1 Specification for ASTM Liquid-in-Glass ThermometersE28 Test Methods for Softening Point of Resins De
6、rived from Naval Stores by Ring-and-Ball ApparatusE2251 Specification for Liquid-in-Glass ASTM Thermometers with Low-Hazard Precision Liquids3. Terminology3.1 Definitions:3.1.1 softening pointthe temperature at which a disk of the sample held within a horizontal ring is forced downward a distanceof
7、1 in. (25.4 mm) under the weight of a steel ball as the sample is heated at a prescribed rate in a glycerin bath.4. Significance and Use4.1 In general, with materials of this type, softening does not take place at a definite temperature.As the temperature rises, thesematerials gradually and impercep
8、tibly change from brittle solids to soft, viscous liquids. For this reason, the determination of thesoftening point must be made by a fixed, arbitrary, and closely defined methods if the results are to be comparable.5. Apparatus5.1 RingA brass-shouldered ring conforming to the dimensions shown in Fi
9、g. 1(a).5.2 BallA steel ball, 9.53 mm (38 in.) in diameter, weighing between 3.45 and 3.55 g.5.3 Ball-Centering GuideA guide for centering the ball, constructed of brass and having the general shape and dimensionsillustrated in Fig. 1(c).5.4 ContainerA glass vessel, capable of being heated, not less
10、 than 85 mm (3.34 in.) in diameter and not less than 127 mm(5 in.) in depth from the bottom of the flare. (An 800-mL, low-form Griffin beaker of heat-resistant glass meets this requirement.)1 This test method is under the jurisdiction of ASTM Committee D21 on Polishes and is the direct responsibilit
11、y of Subcommittee D21.02 on Raw Materials.Current edition approved May 1, 2010Oct. 1, 2013. Published May 2010October 2013. Originally approved in 1978. Last previous edition approved in 20042010 asD3642 98 (2004).(2010).DOI: 10.1520/D3642-98R10.10.1520/D3642-132 For referencedASTM standards, visit
12、theASTM website, www.astm.org, or contactASTM Customer Service at serviceastm.org. For Annual Book of ASTM Standardsvolume information, refer to the standards Document Summary page on the ASTM website.3 The last approved version of this historical standard is referenced on www.astm.org.This document
13、 is not an ASTM standard and is intended only to provide the user of an ASTM standard an indication of what changes have been made to the previous version. Becauseit may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appr
14、opriate. In all cases only the current versionof the standard as published by ASTM is to be considered the official document.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States15.5 Support for Ring and Thermometer, as shown in Fig. 1(d).
15、Note the following requirements:5.5.1 The ring shall be supported in a horizontal position.5.5.2 The bottom of the ring shall be 25.4 mm (1 in.) above the horizontal plate below it.5.5.3 The bottom surface of the horizontal plate shall be at least 12.5 mm (0.5 in.) and not more than 19 mm (0.75 in.)
16、 abovethe bottom of the beaker.5.5.4 The depth of liquid in the beaker shall be not less than 102 mm (4 in.).5.5.5 The thermometer shall be suspended so that the bottom of the bulb is level with the bottom of the ring and within 12.7mm (0.5 in.) but not touching the ring.5.6 ThermometerAn ASTM High
17、Softening Point Thermometer, having a range from 30 to 200C, and conforming to therequirements for Thermometer 16C as prescribed in Specification E1E2251.5.7 Mechanical StirrerA variable-speed, motor-driven stirrer attached to the bottom of a true-vertical shaft must be used toensure uniform heat di
18、stribution. The stirrer shall be positioned and its speed shall be regulated so that the fluid in the bath iscompletely but gently agitated, with no vortexing, turbulence, or air entrainment.6. Precautions6.1 Note the instructions concerning stirrer speed (5.7) and follow closely. Take care that the
19、 stirrer motor does not impartvibrations to the bath through the support system.6.2 Previously boil the glycerin used in the bath in a fume hood.6.3 Rigid adherence to the prescribed rate of heating (Section 8) is absolutely essential to the accuracy and reproducibility ofthis test method. Reject al
20、l tests in which the rate of increase exceeds the limits.FIG. 1 Shouldered Ring, Ring Holder, Ball-Centering Guide, and Assembly of Apparatus Showing Two RingsD3642 1326.4 When the ball drops through the ring, it should be completely surrounded by softened resin and should drop straight downto the l
21、ower horizontal plate.7. Preparation of Sample7.1 Select a sample representative of the resin under test. Select a quantity at least twice that necessary to fill the ring and meltit in a clean container on a hot plate. Take care to avoid overheating the sample or incorporating air bubbles into it; i
22、n no caseshould the sample be heated above the temperature necessary to pour the material readily without inclusion of air bubbles. Thetime from the beginning of heating to the pouring of the sample should not exceed 15 min. Immediately before filling the rings,preheat them to approximately the temp
23、erature at which the resin is to be poured. The rings, while being filled, should rest on asmooth metal plate. Pour the molten resin into the rings so as to leave an excess above the top surface on cooling. Allow the filledring to cool only enough to permit handling the ring. Working quickly, smooth
24、 off the excess resin with a heated metal spatula sothat the top surface of the ring is level and even. Trim off any resin that has adhered to the outer circumference of the ring. Examinethe sample; if it shows any air bubbles or cracks, discard it and prepare another sample.8. Preparation of Appara
25、tus8.1 Fill the glass vessel to a depth of 102 to 108 mm (4 to 414 in.) with boiled glycerin. The starting temperature of the glycerinshall be not less than 45C below the anticipated softening point of the resin. Place the ring in the ring holder, cover it with aball-centering guide, and gently plac
26、e a ball in the center of the guide. Suspend the assembly in the bath and position thethermometer (in accordance with 5.5.5) and start the stirrer.9. Procedure9.1 Apply heat to the bath in such a manner that the temperature of the bath increases 1C/11 to 12 s. This rate of heating iscritical, it mus
27、t be uniform, and should be checked at least once every 5C and the heat source adjusted as necessary. Avoid theeffects of drafts, shielding the apparatus if necessary. Record as the softening point the temperature of the thermometer at theinstant the resin touches the lower horizontal plate. Make no
28、 correction for the emergent stem of the thermometer.10. Precision and Bias10.1 PrecisionDuplicate results by the same operator shall not be considered suspect unless they differ by more than 65C.10.2 BiasThis test has no bias because the values produced are defined only in terms of this test method
29、.11. Keywords11.1 alkali soluble resins; melting point; polish; resins; ring and ball flow point; softening pointASTM 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 advi
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32、you feel that your comments have not received a fair hearing you shouldmake your views 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. Individu
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