1、Designation: D 2663 06Standard Test Methods forCarbon BlackDispersion in Rubber1This standard is issued under the fixed designation D 2663; 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 pare
2、ntheses indicates the year of last reapproval. Asuperscript epsilon (e) indicates an editorial change since the last revision or reapproval.1. Scope1.1 These test methods cover the degree of dispersion ofcarbon black in rubber. Three test methods are described asfollows:SectionsTest Method AVisual I
3、nspection 3-11Test Method BAgglomerate Count 12-23Test Method CMicroroughness Measurement 24-341.2 The values stated in SI units are to be regarded asstandard. No other units of measurement are included in thisstandard.1.3 This standard does not purport to address all of thesafety concerns, if any,
4、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.2. Referenced Documents2.1 ASTM Standards:2D 3182 Practice for RubberMaterials, Equipment, andPr
5、ocedures for Mixing Standard Compounds and Prepar-ing Standard Vulcanized SheetsD 4483 Practice for Evaluating Precision for Test MethodStandards in the Rubber and Carbon Black ManufacturingIndustries2.2 ASTM Adjuncts:Carbon Black Dispersion Standards3Carbon Black Dispersion Chart4TEST METHOD AVISUA
6、L INSPECTION3. Scope3.1 Test Method A is a qualitative visual test method.Ratings are made against a set of standard photographs (Fig.1),3and the results are expressed on a numerical scale.This testmethod cannot be used for compounds that contain fillers otherthan carbon black.4. Summary of Test Met
7、hod4.1 The compound rubber is torn or cut to expose a freshsurface for examination by the eye, aided preferably by a handlens or a low-power binocular microscope. The dispersionlevel of the carbon black is compared against a series of fivephotographic standards and then rated numerically from 1(very
8、 low) to 5 (high) (see Fig. 1).5. Significance and Use5.1 Visual dispersion ratings correlate with certain impor-tant physical properties of the compound. A rating of 5indicates a state of dispersion developing near maximumproperties, while a rating of 1 would indicate a state ofdispersion developin
9、g considerably depressed properties. Nor-mally, the visual dispersion ratings indicate the followinglevels of compound quality:Visual Dispersion Rating Classification4to5 High3 to 4 Intermediate2to3 Low1 to 2 Very low6. Apparatus6.1 Sharp Knife or Razor Blade.6.2 Hand Lens (103) or binocular microsc
10、ope (10 to 203).6.3 Illuminator, microscopical-type.6.4 Knife Heater.6.5 Series of Photographic Standards, rating 1 to 5. Thesestandards give the following percent dispersion ratings by theAgglomerate Count Method:1These test methods are under the jurisdiction of ASTM Committee D24 onCarbon Black an
11、d are the direct responsibility of Subcommittee D24.71 on CarbonBlack Testing in Rubber.Current edition approved Oct. 1, 2006. Published November 2006. Originallyapproved in 1967. Last previous edition approved in 2006 as D 2663 95a (2006).2For referenced ASTM standards, visit the ASTM website, www.
12、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.3Available from ASTM International Headquarters. Order Adjunct No.ADJD266302. Original adjunct produced in 1967.4Availabl
13、e from ASTM International Headquarters. Order Adjunct No.ADJD266301. Original adjunct produced in 1967.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.Visual Rating Black Dispersed, %170283914965997. Test Specimen7.1 Vulcanized Compo
14、undsUse a slab of rubber about2 mm in thickness. Tear it so that a fresh surface is exposed.The tear may be initiated by a small cut. The most nearly flatpart of the tear is used for rating.7.2 Unvulcanized CompoundsUnvulcanized rubber maybe examined as follows:7.2.1 If the specimen contains curing
15、agents, sheet it out andcure in a press to form a vulcanized slab about 2 mm inthickness. Mill and cure in accordance with Practice D 3182.Then proceed as in 7.1.FIG. 1 Carbon Black Dispersion StandardsVisual Analysis of Torn VulcanizatesD26630627.2.2 If the specimen contains no curatives, add the a
16、ppro-priate materials with a minimum of mixing. Then cure andproceed as above.7.2.3 If the specimen contains no curatives and a dispersionevaluation with no further mixing is required, the compoundmust first be compressed to remove most of the air holes. Toaccomplish this, press the rubber into a sl
17、ab between thinsheets of plastic in a mold at a pressure of about 1.03 kPa for5 min at 105C. Care should be taken to avoid excessive flowduring this step. The surface to be examined is formed with asmooth cutting stroke using a sharp, hot knife (a standard typeknife heater may be employed). The most
18、 nearly smooth andflat part of the cut surface is used for rating.8. Number of Tests8.1 Preferably more than one test (on different tears) shouldbe made for each specimen. If convenient, more than oneoperator should rate the samples.9. Procedure9.1 Examine the prepared specimens under a hand lens or
19、binocular microscope (the latter being preferred), with obliqueillumination to accentuate surface detail. Keep the magnifica-tion and lighting conditions constant for all specimens.9.2 Compare the size and frequency of carbon agglomeratesin the specimens (showing up as surface bumps or depressions)t
20、o the photographic standards. Then assign the most closelymatched numerical rating to each compound being rated. Inborderline cases, use fractional ratings, for example, 312 wouldindicate a rating between 3 and 4. In cases of dissimilarity inthe size and frequency of the agglomerates in the specimen
21、 andthose of the standards, the operator shall assign the rating thatin his judgment is most applicable. Certain compounds (forexample, NR and IR) are particularly prone to very small blackagglomerations which are difficult to resolve by the VisualInspection Method. In instances of high agglomerate
22、fre-quency, the surface of stocks of this type may show a generalroughness or fine pebbled appearance. Differences are bestresolved at somewhat higher magnification (for example, 203,binocular microscope). If at all possible, examine compoundsof this type also by the agglomerate count method, at lea
23、st untilsufficient experience is gained to recognize dispersion differ-ences with the Visual Inspection Method.9.3 In comparing a series of different compounds, it is alsodesirable to rate the specimens side by side rather than one ata time. This use of a control compound is also advisable. Thisis b
24、est prepared by individual operators, since dispersionrequirements may vary greatly for different types of com-pounds. The control sample should represent a minimumacceptable dispersion level for the type of compound beingrated. Because it can be observed side by side with unknownsamples under ident
25、ical conditions, a control compound ismore accurate than the photographic standards in discerningsmall deviations from what is considered the norm for aspecific type of compound. Prepare a fresh surface on thecontrol as often as necessary to ensure cleanliness.10. Report10.1 Ratings:10.1.1 List all
26、ratings, including those on any controlcompound, on the basis of the 1 to 5 scale defined by thestandard photographs. Use fractional ratings when necessary.10.1.2 Average the ratings on different specimens of thesame compound as well as the ratings of different operators.Report the final average val
27、ues.10.2 Compound Identification:10.2.1 FormulationWhenever possible list the following:10.2.1.1 Carbon black, type and loading,10.2.1.2 Other fillers, type and loading,10.2.1.3 Polymer type, and10.2.1.4 Extender oil, type and loading.10.2.2 MixingDescribe the mixing of the compound interms of one o
28、r more of the following:10.2.2.1 Standard mixing procedure,10.2.2.2 Type of equipment,10.2.2.3 Masterbatch,10.2.2.4 Finished compound (vulcanized), and10.2.2.5 Finished compound (unvulcanized).11. Precision and Bias11.1 No statement is made about either the precision or thebias of Test Method A sinc
29、e the result is qualitative and notapplicable to statistical treatment.TEST METHOD BAGGLOMERATE COUNT12. Scope12.1 Test Method B is a quantitative test method. Dispersionis evaluated by measuring with a light microscope the percent-age area covered by black agglomerates in microtomed sec-tions of th
30、e compound. Since this test method involves directmeasurement, it is quantitative and more accurate than thevisual test method. The test is applicable to the analysis ofcarbon black dispersion in compounds that contain other fillers.13. Summary of Test Method13.1 The compounded rubber is microtomed
31、into sectionssufficiently thin to permit observation of the carbon agglom-erates by transmitted light, with the aid of a light microscope.The total cross-sectional area of all agglomerates 5 m orlarger is counted, and from the known content of carbon blackin the stock, the percentage of carbon black
32、 below the 5-msize is calculated and expressed as “Percentage of CarbonBlack Dispersed.”14. Significance and Use14.1 Certain important physical properties of the compoundare influenced significantly by the degree of carbon blackdispersion within the compound (for example, tensile strengthand abrasio
33、n resistance). The correlation of these propertieswith the percentage dispersion determined by the AgglomerateCount Method approximates the following pattern for manytypes of black loaded rubber compounds:Dispersion, % ClassificationAbove 99 Very high97 to 99 High95 to 97 Intermediate92 to 95 LowD26
34、63063Below 92 Very low15. Apparatus15.1 MicrotomeA sledge-type microtome equipped withspecimen clamp and holder for glass knives. Steel knives mayalso be employed, according to the preference of the operator.15.2 Freezing Blocks, consisting of a brass screw which isthreaded into an insulating block
35、of TFE-fluorocarbon (Fig. 2).The TFE-fluorocarbon block shall be 28-mm square in crosssection and 40-mm high. The threaded part of the brass screwshall be 15 mm in diameter and shall extend into the center ofthe TFE-fluorocarbon block to a depth of 34 mm. Coarse,expansion-type threads should be used
36、 to prevent splitting ofthe TFE-fluorocarbon when the mount is frozen. The head ofthe brass screw shall be 18 mm in diameter and shall extend3 mm above the TFE-fluorocarbon insulator. The top of thescrew head shall be cross-hatched with fine grooves to a depthof about 1 mm.15.3 MicroscopeAn optical
37、microscope with binocularviewing (trinocular type if photomicrographs are desired) isrecommended. This should include a movable specimen stageand white light source with variable intensity. Lenses shouldinclude two 103 wide field eyepieces and objectives in therange from 6 to 103. Taking into accoun
38、t microscope tubecorrections, objectives should be selected so that magnifica-tions in the range from 75 to 1003 are available. (Forphotomicrographs a 43 plane objective and a 103 periplanaticeyepiece are recommended.)15.4 Microscope AccessoriesA 103 wide field eyepiececontaining a graticule that is
39、 1 cm2in size and divided into10 000 small squares.15.5 Measuring LensA 73 measuring magnifier cali-brated down to 0.1 mm for measuring the swelling factor of themicrotome sections. A mechanical vernier stage can also beused for this purpose.15.6 Glass Pliers and CutterWide-face glazier pliers anda
40、wheel-type glass cutter are recommended for preparing glassknives.15.7 Sample DieTempered steel die for cutting out 3 by8-mm specimens.15.8 Sable Brushes (00).15.9 Dewar Flask, 2dm3(2-L) size (wide-mouth).15.10 Glass KnivesThe knives are prepared from 50-mmwide strips of approximately 6-mm thick pla
41、te glass.15.11 Microscope Slides and Cover Glasses.16. Reagents and Materials16.1 Liquid Nitrogen.16.2 Water-Soluble Mucilage.16.3 Naphtha, boiling point range from about 113 to 144C.16.4 Xylene, boiling point range from 135 to 145C.17. Sampling17.1 VulcanizatesSpecimens may be cut from standardtest
42、 sheets (about 2-mm thick) or from pieces of actual curedarticles. Vulcanized samples must be employed because of thesolvent used to uncurl the thin sections. If pieces other than2-mm sheets are used, they should first be cut down to athickness of about 2 to 3 mm.17.2 Unvulcanized CompoundsFor rubbe
43、rs of high unsat-uration (for example, OE-SBR, NR, and BR), dust small bits(enough subsequently to form buttons about 10 mm in diameterand about 2 to 3-mm deep) thoroughly with dicumyl peroxide.Cure in a button mold5under high pressure at about 155C.OE-SBR rubbers require about 30 to 60-min cure. BR
44、 requiresabout 10 to 15-min cure. After cure, scrape off the excessperoxide from the sample surface and proceed with sectioningin the standard manner, taking care not to pare down below thecured surface layer.17.2.1 For IIR, satisfactory surface cures can be obtainedwith a mixture of 1 part tetramet
45、hylthiuram disulfide (TMTD),1 part mercaptobenzothiazole (MBT), 1 part sulfur, and 5 partszinc oxide, with a cure of 1 h at 155C. Other alternativeapproaches for curing high unsaturation polymers withoutactually mixing in curatives are (1) high-energy radiation and(2) chemical treatment with sulfur
46、monochloride. However,before using either of these latter methods, the stock should bepressed out to eliminate most of the air holes. Cure inaccordance with Practice D 3182.18. Test Specimen18.1 Cut out a rectangular specimen 8-mm long, 3-mmwide, and approximately 2-mm deep. Use a cutting die, ifava
47、ilable. If a die is not used, the specimen length and widthshould be recorded using a measuring magnifier.18.2 Prepare one specimen block for each different com-pound to be examined.19. Preparation of Glass Knives19.1 Standard types of plate glass are suitable for makingknives. Thickness should be p
48、referably about 6 mm. A largesheet of glass should first be repeatedly broken in half so thatit eventually is in 50-mm wide strips. Fracture in this manneris preferred over simply breaking off 50-mm sections one at atime. Uneven strains are encountered in the latter procedure,and irregularities may
49、occur on the side faces on which theknife edge will be formed. Prior to fracture, it is also importantthat the glass be free of dirt. A wash in a liquid detergent isgenerally advisable.5A special mold containing several circular cavities that are approximately10 mm in diameter and 3 mm deep.FIG. 2 Brass Sample Mount and TFE-Fluorocarbon InsulatorD266306419.2 Using a fairly thick straightedge, score a straight line(perpendicular to the side faces) across the glass strip, 50 mmfrom the end. Take care that the score mark does not actuallyextend all the way
