1、Designation: D 2414 08aStandard Test Method forCarbon BlackOil Absorption Number (OAN)1This standard is issued under the fixed designation D 2414; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last revision. A number
2、in parentheses indicates the year of last reapproval. Asuperscript epsilon () 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 This test method covers the determination of the oilabsorptio
3、n number of carbon black.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, associated with its use. It is theresponsibility of the user of this
4、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 1765 Classification System for Carbon Blacks Used inRubber ProductsD 1799 Practice for Carbon BlackSampling PackagedShip
5、mentsD 1900 Practice for Carbon BlackSampling Bulk Ship-mentsD 4483 Practice for Evaluating Precision for Test MethodStandards in the Rubber and Carbon Black ManufacturingIndustriesD 4821 Guide for Carbon BlackValidation of TestMethod Precision and Bias3. Summary of Test Method3.1 In this test metho
6、d, oil is added by means of aconstant-rate buret to a sample of carbon black in the mixerchamber of an absorptometer. As the sample absorbs the oil,the mixture changes from a free-flowing state to one of asemiplastic agglomeration, with an accompanying increase inviscosity. This increased viscosity
7、is transmitted to the torque-sensing system of the absorptometer. When the viscosity of themixture reaches a predetermined torque level, the absorptom-eter and buret will shut off simultaneously. The volume of oiladded is read from the direct-reading buret. The volume of oilper unit mass of carbon b
8、lack is the oil absorption number.3.2 Either DBP or paraffin oil is acceptable for use withstandard pelleted grades including N-series carbon blacksfound in Classification D 1765. OAN testing using paraffin oilon some specialty blacks and powder blacks may result inunacceptable differences as compar
9、ed to OAN testing usingDBP oil. While studies have shown either oil to exhibitcomparable precision, paraffin oil offers the advantage of beingnon-hazardous; even FDA-approved grades are available. Foreither oil, Sections 8-11 (Calibration, Procedure, Calculation,and Report) are to be consistent with
10、 the oil selected for use.Referee testing between suppliers and users should use DBPoiluntil such time that precision data are available for paraffin oil.4. Significance and Use4.1 The oil absorption number of a carbon black is related tothe processing and vulcanizate properties of rubber compoundsc
11、ontaining the carbon black.5. Apparatus35.1 Balance, analytical, with an 0.01-g sensitivity.5.2 Oven, gravity-convection type, capable of maintaining125 6 5C.5.3 Spatula, rubber, 100-mm.5.4 Absorptometer, equipped with a constant-rate buret thatdelivers 4 6 0.024 cm3/min.45.5 Desiccator.6. Reagent a
12、nd Standards6.1 Purity of ReagentsReagent grade chemicals shall beused in all tests. Unless otherwise indicated, it is intended thatall reagents shall conform to the specifications of the Commit-tee on Analytical Reagents of the American Chemical Society,1This test method is under the jurisdiction o
13、fASTM Committee D24 on CarbonBlack and is the direct responsibility of Subcommittee D24.11 on Carbon BlackStructure.Current edition approved Aug. 1, 2008. Published September 2008. Originallyapproved in 1965. Last previous edition approved in 2008 as D 2414 08.2For referenced ASTM standards, visit t
14、he 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.3All apparatus are to be operated and maintained in accordance with themanufacturers directions for
15、optimum performance.4Available from C. W. Brabender Instruments, Inc., 50 E. Wesley St., SoutHackensack, NJ 07606 () and from HITEC Luxembourg, 5 Ruede lEglise, L-1458 Luxembourg (www.hitec.lu).1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, Unite
16、d States.where such specifications are available.5Other grades may beused, provided it is first ascertained that the reagent is ofsufficiently high purity to permit its use without lessening theaccuracy of the determination.6.2 n-Dibutyl Phthalate, having a density of 1.042 to 1.047Mg/m3at 25C and a
17、 relative density of 1.045 to 1.050 at 25C.6.3 Paraffn Oil, having a kinematic viscosity of 10 to34 mm2/s (cSt) at 40C.NOTE 1Three paraffin oils have been found suitable including Marcol82 from Exxon, 80/90 White Oil from Conoco-Phillips, and LC1 oil fromLab Chemicals, Germany. All three oils are ph
18、armaceutical or food gradeoil, or both, based on available data.6.4 ASTM D24 Standard Reference Blacks, SRB-6.67. Sampling7.1 Samples shall be taken in accordance with PracticesD 1799 and D 1900.8. Calibration and Standardization8.1 Absorptometer:8.1.1 ModelThree different types of absorptometers ar
19、e inuse: 1) early models based on springs and mechanical indica-tion of torque (Type A and B), 2) second generation absorp-tometers equipped with load cells and digital torque display(Type E), and 3) current model absorptometers controlled viamicrocomputer software (Type C and H) and Type E absorp-t
20、ometers which utilize add-on data acquisition and controlsystems. Several components influence the calibration: thedynamometer torque spring or the load cell, the torque limitswitch or the indicator set-point, the damper (oil damper orelectronic damping), and the mixing head consisting of twocounter
21、-rotating blades and a mixing bowl. It is necessary thatall of these components are in good condition and are properlyadjusted to achieve acceptable calibration.8.1.2 Mixing BowlTypically the absorptometer is deliv-ered with either a surface-treated stainless steel or anodizedaluminum mixing bowl. T
22、hese bowls are considered accept-able provided they give the correct reading for the appropriateSRB reference standards. The surface finish of the mixerchamber is critical for maintaining proper calibration, and thebowl should not be modified to achieve calibration.NOTE 2Stainless steel chambers hav
23、e been found satisfactory for thetest when they are manufactured to a roughness value (Ra) of 2.5 60.4 m (100 6 15 in.) based upon 8 measurements. No single measure-ment should be greater than 3.6 m (140 in.) or less than 1.5 m (60in.). Stainless steel bowls purchased with an absorptometer have been
24、pre-polished for 16 h to minimize bowl surface changes affectingcalibration during their initial use. It is recommended that new replace-ment stainless steel bowls should also be pre-polished in the same manner(see Annex A3).8.2 Calibration:8.2.1 Rotor BladesThe speed of the motor driving therotor b
25、lades is either fixed (Type A and B) or has to be set(Type E, C, and H) to 125 r/min. Due to a gear, one blade spinsat 125 r/min, the other blade at 250 r/min.8.2.2 Constant-Rate BuretThe delivery rate of the buret isto be 4 cm3/min. SeeAnnexA1 for detailed instructions on theprocedure for calibrati
26、on check of the constant-rate buret.8.2.3 Spring Tension (Type A and B)It is recommendedthat the torque spring is adjusted so that the SRB F standardwill develop a maximum torque between 70 % and full-scaledeflection. This is achieved by selecting the appropriate springstrength and adjusting the spr
27、ing tension in accordance with theinstructions of the manufacturer.NOTE 3The absorptometers Type E, C, and H are calibrated by themanufacturer to give a direct reading of torque in mNm; this calibrationshould not be modified in order to achieve a desired level of torque. Ifcalibration is necessary,
28、refer to the instrument manufacturers recommen-dations. The instrument torque calibration should not be confused with thetorque limit switch described in 8.2.5.8.2.4 DamperFor the Type A absorptometer, it is recom-mended to keep the valve of the oil damper fully closed. TheType B absorptometer shall
29、 provide a full-scale recovery of 36 0.5 s; the valve has to be adjusted accordingly. The Type Eabsorptometer has an electronic damping option and Types Cand H have appropriate software damping. Make sure thatthese damping options are activated.8.2.5 Torque Limit Switch (TLS) or the Indicator SetPoi
30、ntIf the end-point of the test is determined by a fixedtorque limit, the setting of the TLS, also called indicatorset-point, has to be selected using one of the following threeprocedures:8.2.5.1 Procedure A: End-Point at Fixed Torque LevelThis “classical” method is well suited for hard or tread blac
31、ksbut often leads to problems when low-torque carcass blacks areto be tested. For Type A and B absorptometers, adjust the TLSor the indicator set point in such way that the current SRB Fstandard gives the correct target values within the limits asdefined in Guide D 4821. For Type E absorptometers de
32、dicatedto testing carcass blacks only, set the TLS in such a way thatthe current SRB F standard gives the correct target valueswithin the limits as defined in Guide D 4821. For Type E, C,and H absorptometers dedicated to testing tread blacks only,there is no advantage to setting the TLS with current
33、 SRB Fstandard; for these absorptometers set the TLS between 3000and 4000 mNm (preferred TLS is 3500 mNm when using DBPoil, or 4000 mNm if using paraffin oil).8.2.5.2 Procedure B: End-Point at 70 % of the MaximumTorqueCertain carcass blacks and thermal blacks may fail togive an end-point due to insu
34、fficient torque level. Therefore,the preferred method for testing soft blacks is to record thetorque curve using a chart-recorder or a data acquisition systemand to read the end-point at 70 % of the maximum of the torqueachieved. Set the TLS or the indicator set point to full scale inorder to disabl
35、e the automatic shut-off of the absorptometer.5Reagent Chemicals, American Chemical Society Specifications , AmericanChemical Society, Washington, DC. For suggestions on the testing of reagents notlisted by the American Chemical Society, see Analar Standards for LaboratoryChemicals, BDH Ltd., Poole,
36、 Dorset, U.K. and the United States Pharmacopeia andNational Formulary, U.S. Pharmacopeial Convention, Inc. (USPC), Rockville, MD.6The sole source of supply of the apparatus known to the committee at this timeis Laboratory Standards and Technologies, 227 Somerset, Borger, TX 79007. If youare aware o
37、f alternative suppliers, please provide this information to ASTMInternational Headquarters. Your comments will receive careful consideration at ameeting of the responsible technical committee,1which you may attend.D 2414 08a28.2.5.3 Procedure C: End-Point at a Fixed, But ReducedTorque LevelRequires
38、use of SRB-5 series standards. SeeTest Method D 2414 00.8.3 Standardization:8.3.1 Physically calibrate the test apparatus including TLSadjustment using the instructions in 8.2.8.3.2 Test the sixASTM Standard Reference Blacks (SRBs)in duplicate to establish the average measured value. Addi-tional val
39、ues are added periodically, typically on a weeklybasis. The rolling average of the measured values is computedfrom the latest four values.NOTE 4When only tread- or carcass-type carbon blacks are to betested, the calibration can be limited to either the three tread- (A, B, C) orthe three carcass-type
40、 (D, E, F) carbon black standards.8.3.3 Perform a regression analysis using the standard valueof the standard (y value) and the rolling average measuredvalue (x value). Separate carcass and tread calibration curvesshould be maintained.8.3.4 Normalize the values of all subsequent samples asfollows:No
41、rmalized value 5 measured value 3 slope! 1 yintercept (1)8.3.5 For measured values on the SRBs that are consistentlyoutside the expected variability listed in Guide D 4821, the testapparatus should be recalibrated in accordance with 8.2.8.3.6 When any absorptometer or calibration changes occur,a new
42、 calibration curve must be initiated as described in 8.3.2.8.3.7 In most instances, if proper calibration cannot beachieved by following 8.2 or 8.3.2-8.3.4, it will be necessary toreplace the mixer chamber with one of proper surface finish.9. Procedure9.1 Dry an adequate sample for1hinthespecified o
43、ven setat 125C. Prior to testing, cool the sample in a desiccator for aminimum of 30 min.9.2 Weigh the sample to the nearest 0.01 g. The recom-mended masses are as follows:Carbon Black Mass, gN630, N642, and N700 series, except N765 25N800 and N900 series, SRB D-7 40All others 209.3 It is recommende
44、d that a testing temperature of 23 65C be maintained, as measured by a thermocouple in themixing bowl. If a temperature controllable mixing bowl is notavailable, keep the bowl temperature below 30C and complywith Note 5 and Note 6 while running the samples.NOTE 5If the absorptometer has remained idl
45、e for more than 15 minand a temperature controllable bowl is not being used, a 10-min warm-upsample must be run before beginning a test. It is important that the mixerchamber temperature be kept uniform. Preferably, allow 5 min betweenthe end of one test and the start of another.NOTE 6It is importan
46、t that the temperature of the bowl be the samefor machine calibration as for oil absorption testing. ASTM task groupwork has shown that an increase in bowl temperature can cause highervalues that increased variability in bowl temperatures cause increased testvariability.NOTE 7In the event that an en
47、dpoint is not obtained (maximumtorque TLS) when using an absorptometer with a fixed TLS such asType B or E, it is acceptable to mill pelleted carbon blacks using a coarsegrinder such as a coffee mill. The carbon black should be milled for onlya few seconds to allow sufficient grind time to change th
48、e pellets topowder form. High-speed micronizing mills and air-jet mills are notacceptable, as they can reduce the carbon black structure.9.4 Transfer the sample to the absorptometer mixer chamberand replace the chamber cover. For Type H, close the safetydoor surrounding the mixing chamber.9.5 Positi
49、on the buret delivery tube over the hole in themixer chamber cover, and for Types A, B, or E set the buretdigital counter to zero (Types C and H have automatic reset).Insure the buret delivery tubes have no air bubbles.9.6 Activate the “start” button. On the Type E absorptom-eter, activate both “start” buttons simultaneously. The appara-tus will operate until one of the following conditions are met:1) sufficient torque has developed to activate the torque-limitswitch, which will halt the absorptometer and buret; 2) thesamp
