1、Designation: D 3642 98 (Reapproved 2004)Standard Test Method forSoftening Point of Certain Alkali-Soluble Resins1This standard is issued under the fixed designation D 3642; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year o
2、f last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon (e) indicates an editorial change since the last revision or reapproval.1. Scope1.1 This test method covers the determination of the soft-ening point of certain alkali-soluble resins having uniformpl
3、astic flow characteristics as the melting point is approached.1.2 The resin manufacturer should specify whether or notthis test method may be used for his product(s).1.3 This test method is not suitable for styrene-maleicanhydride resins.NOTE 1For testing rosin and other resins, see Test Method E 28
4、. Fortesting asphalts, tars, and pitches, see Test Method D 2398.1.4 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 and determine the appl
5、ica-bility of regulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:2D 2398 Test Method for Softening Point of Bitumen inEthylene Glycol (Ring and Ball)E 1 Specification for ASTM ThermometersE 28 Test Method for Softening Point by Ring and BallApparatus3. Terminology3.1 Defin
6、ition:3.1.1 softening pointthe temperature at which a disk ofthe sample held within a horizontal ring is forced downward adistance of 1 in. (25.4 mm) under the weight of a steel ball asthe sample is heated at a prescribed rate in a glycerin bath.4. Significance and Use4.1 In general, with materials
7、of this type, softening doesnot take place at a definite temperature. As the temperaturerises, these materials gradually and imperceptibly change frombrittle solids to soft, viscous liquids. For this reason, thedetermination of the softening point must be made by a fixed,arbitrary, and closely defin
8、ed methods if the results are to becomparable.5. Apparatus5.1 RingA brass-shouldered ring conforming to the di-mensions shown in Fig. 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 a
9、nd having the general shape and dimen-sions illustrated in Fig. 1(c).5.4 ContainerA glass vessel, capable of being heated, notless than 85 mm (3.34 in.) in diameter and not less than 127mm (5 in.) in depth from the bottom of the flare. (An 800-mL,low-form Griffin beaker of heat-resistant glass meets
10、 thisrequirement.)5.5 Support for Ring and Thermometer, as shown in Fig.1(d). 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.) abovethe horizontal plate below it.5.5.3 The bottom surface of the horizontal
11、 plate shall be atleast 12.5 mm (0.5 in.) and not more than 19 mm (0.75 in.)above the bottom of the beaker.5.5.4 The depth of liquid in the beaker shall be not less than102 mm (4 in.).5.5.5 The thermometer shall be suspended so that thebottom of the bulb is level with the bottom of the ring andwithi
12、n 12.7 mm (0.5 in.) but not touching the ring.5.6 ThermometerAn ASTM High Softening Point Ther-mometer, having a range from 30 to 200C, and conforming tothe requirements for Thermometer 16C as prescribed in Speci-fication E 1.5.7 Mechanical StirrerA variable-speed, motor-drivenstirrer attached to th
13、e bottom of a true-vertical shaft must beused to ensure uniform heat distribution. The stirrer shall bepositioned and its speed shall be regulated so that the fluid inthe bath is completely but gently agitated, with no vortexing,turbulence, or air entrainment.6. Precautions6.1 Note the instructions
14、concerning stirrer speed (5.7) andfollow closely. Take care that the stirrer motor does not impartvibrations to the bath through the support system.1This test method is under the jurisdiction of ASTM Committee D21 on Polishesand is the direct responsibility of Subcommittee D21.02 on Raw Materials.Cu
15、rrent edition approved Sept. 1, 2004. Published September 2004. Originallyapproved in 1978. Last previous edition approved in 1998 as D 3642 98.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards v
16、olume 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.6.2 Previously boil the glycerin used in the bath in a fumehood.6.3 Rigid adherence to the prescribed
17、rate of heating (Sec-tion 8) is absolutely essential to the accuracy and reproducibil-ity of this test method. Reject all tests in which the rate ofincrease exceeds the limits.6.4 When the ball drops through the ring, it should becompletely surrounded by softened resin and should dropstraight down t
18、o the lower 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 andmelt it in a clean container on a hot plate. Take care to avoidoverheating the sample or incorporating air bubbles into
19、it; inno case should the sample be heated above the temperaturenecessary to pour the material readily without inclusion of airbubbles. The time from the beginning of heating to the pouringof the sample should not exceed 15 min. Immediately beforefilling the rings, preheat them to approximately the t
20、emperatureat which the resin is to be poured. The rings, while being filled,should rest on a smooth metal plate. Pour the molten resin intothe rings so as to leave an excess above the top surface oncooling. Allow the filled ring to cool only enough to permithandling the ring. Working quickly, smooth
21、 off the excess resinwith a heated metal spatula so that the top surface of the ringis level and even. Trim off any resin that has adhered to theouter circumference of the ring. Examine the sample; if itshows any air bubbles or cracks, discard it and prepare anothersample.8. Preparation of Apparatus
22、8.1 Fill the glass vessel to a depth of 102 to 108 mm (4 to414 in.) with boiled glycerin. The starting temperature of theglycerin shall be not less than 45C below the anticipatedsoftening point of the resin. Place the ring in the ring holder,cover it with a ball-centering guide, and gently place a b
23、all inthe center of the guide. Suspend the assembly in the bath andposition the thermometer (in accordance with 5.5.5) and startthe stirrer.FIG. 1 Shouldered Ring, Ring Holder, Ball-Centering Guide, and Assembly of Apparatus Showing Two RingsD 3642 98 (2004)29. Procedure9.1 Apply heat to the bath in
24、 such a manner that thetemperature of the bath increases 1C/11 to 12 s. This rate ofheating is critical, it must be uniform, and should be checkedat least once every 5C and the heat source adjusted asnecessary. Avoid the effects of drafts, shielding the apparatus ifnecessary. Record as the softening
25、 point the temperature of thethermometer at the instant the resin touches the lower horizon-tal plate. Make no correction for the emergent stem of thethermometer.10. Precision and Bias10.1 PrecisionDuplicate results by the same operatorshall not be considered suspect unless they differ by more than6
26、5C.10.2 BiasThis test has no bias because the values pro-duced are defined only in terms of this test method.11. Keywords11.1 alkali soluble resins; melting point; polish; resins; ringand ball flow point; softening pointASTM International takes no position respecting the validity of any patent right
27、s 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 infringement of such rights, are entirely their own responsibility.This standard is subject to revision at any t
28、ime 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 or for additional standardsand should be addressed to ASTM International Headquarters. Your comments will
29、 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 known to the ASTM Committee on Standards, at the address shown below.This standard is copyrighted by ASTM
30、 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).D 3642 98 (2004)3
