1、Designation: D 4620 02 (Reapproved 2007)Standard Test Method forEvaluating the Effective Surface Area of Zinc Oxide inRubber1This standard is issued under the fixed designation D 4620; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision
2、, the year of 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 specifies the standard materials, mix-ing procedure, and test method for ranking zinc-
3、oxide samplesaccording to their specific surface area in a standard testformula based on chloroprene rubber (CR).1.2 The ranking is based on the cure time of the standard CRformulation.1.3 The accurate surface area cannot be determined by thistest method, since factors other than surface area may in
4、fluencethe cure times to some extent (for example acidity, heavy metaltraces, etc.).1.4 The values stated in SI units are to be regarded as thestandard. The values given in parentheses are for informationonly.1.5 This standard does not purport to address all of thesafety concerns, if any, associated
5、 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 1646 Test Methods for RubberViscosity, Stress Relax-ation, an
6、d Pre-Vulcanization Characteristics (Mooney Vis-cometer)D 2084 Test Method for Rubber PropertyVulcanizationUsing Oscillating Disk Cure MeterD 3190 Test Method for RubberEvaluation of Chloro-prene Rubber (CR)D 5289 Test Method for Rubber PropertyVulcanizationUsing Rotorless Cure Meters3. Summary of T
7、est Method3.1 Separate formulations of a chloroprene-rubber com-pound are prepared containing 3-methyl-thiazolidine-thione-2and other compounding materials. One or more formulation(s)contain the experimental or candidate zinc-oxide grade(s) to beevaluated and the other standard formulation(s) one or
8、 morezinc-oxide grade(s) of known surface area.3.2 The cure times (t890) of the formulations are measuredas specified in Test Method D 2084 or D 5289 and used to rankthe unknown zinc-oxide with respect to the standard containingzinc oxide of known surface area.3.3 Longer cure times indicate lower su
9、rface areas, andshorter cure times indicate higher surface areas.4. Significance and Use4.1 The surface area of zinc-oxide in rubber can signifi-cantly affect cure activation and vulcanizate properties.4.2 The specific surface area of zinc-oxide is usually mea-sured by nitrogen absorption which requ
10、ires the use of equip-ment not normally found in rubber laboratories. This testmethod allows a ranking of zinc-oxide samples according totheir surface areas with respect to a known standard using asimplified procedure involving mixing of rubber compoundsand measuring cure times with oscillating disk
11、 or rotorless curemeters.4.3 This test method may be used for quality control,research and development work, and comparison of differentzinc-oxide samples.5. Standard Test Formula5.1 The standard test formula is similar to Formula B in TestMethod D 3190, except for the curative (see Table 1).1This t
12、est method is under the jurisdiction of ASTM Committee D11 on Rubberand is the direct responsibility of Subcommittee D11.20 on Compounding Materialsand Procedures.Current edition approved Nov. 1, 2007. Published January 2008. Originallyapproved in 1986. Last previous edition approved in 2002 as D 46
13、20 02.2For referenced ASTM standards, visit the ASTM website, www.astm.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, P
14、O Box C700, West Conshohocken, PA 19428-2959, United States.5.2 For meaningful results, it is necessary to use the samelot of raw materials within each test series.6. Mixing Procedures6.1 The mill mixing procedure outlined in Test MethodD 3190 (6.1.2., Method B and 6.4) is employed.6.2 Mill-roll tem
15、peratures are adjusted to 50 6 5C (122 69F) and stock temperatures should reach 75 6 5C (167 69F) to assure melting and satisfactory dispersion of thecurative.6.3 It is recommended that the 3-methyl-thiazolidine-thione-2 be pulverized in order to prevent any loss by granulespopping off the mill duri
16、ng the mixing cycle.7. Testing7.1 Individual formulations containing one or more zinc-oxide samples of unknown and known surface areas are mixedand t890 times are measured in accordance with Test MethodD 2084 or Test Method D 5289, using a temperature of 160C(320F).7.2 The t890 times of the formulat
17、ion(s) containing zinc-oxide of unknown surface area are ranked with respect to theknown standard(s) and each other.7.3 As zinc-oxide standard IRM 913or any other grade ofknown surface area, or both can be employed.7.4 Similar t890 times indicate similar surface areas, com-pared to the standard.7.5
18、Shorter t890 times indicate a higher surface area com-pared to the standard.7.6 Longer t890 times indicate a lower surface area com-pared to the standard.8. Report8.1 The report shall include the following information:8.1.1 Proper identification of samples,8.1.2 Cure meter results: t890 times, test
19、method used, and8.1.3 Ranking of samples according to t890 times, indicatingwhether the samples have a higher, lower, or similar surfacearea compared to the known standard(s).9. Precision and Bias9.1 A precision and bias statement is not applicable, sincethis test method employs data only to provide
20、 a ranking ofsamples with respect to each other.10. Keywords10.1 curemeter; surface area; zinc oxideASTM 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 dete
21、rmination 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 time by the responsible technical committee and must be reviewed every five years andif not revised, either reapproved or
22、 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 receive careful consideration at a meeting of theresponsible technical committee, which you may attend. If you feel tha
23、t 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. Individual reprints
24、(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).3Available from R. E. Carroll, Inc., P.O. Box 5806 Trenton, NJ 086380806.TABLE 1
25、Standard Test FormulaMaterials Parts by MassChloroprene-rubber (mercaptan modified)A100.0AntioxidantB1.0Magnesium-oxideC4.0N 774 black 30.0Zinc-oxide 5.03-methyl-thiazolidine-thione-2 (curative)D0.5140.5AMooney viscosity 4050 (ML 1 + 48 at 100C (212F), see Test MethodsD 1646) medium crystallization
26、rate.BOctylated diphenylamine.CScorchguard O available from Rhein Chemical Corp., 1008 Whitehead Rd.Ext., Trenton, NJ 08638.DVulkacit CRV/LG available from Miles, Inc., Polysar Rubber Division, 2603 W.Market St., Akron, OH 44313 or Bayer AG., Business Group Rubber, 5090Leverkusen, Germany.D 4620 02 (2007)2
