1、Designation: D2414 11Standard Test Method forCarbon BlackOil Absorption Number (OAN)1This standard is issued under the fixed designation D2414; 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
2、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 oilabsorption n
3、umber 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 sta
4、ndard 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:2D1765 Classification System for Carbon Blacks Used inRubber ProductsD1799 Practice for Carbon BlackSampling PackagedShipments
5、D1900 Practice for Carbon BlackSampling Bulk Ship-mentsD4483 Practice for Evaluating Precision for Test MethodStandards in the Rubber and Carbon Black ManufacturingIndustriesD4821 Guide for Carbon BlackValidation of Test MethodPrecision and Bias3. Summary of Test Method3.1 In this test method, oil i
6、s 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 is trans
7、mitted 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 black is
8、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 D1765. OAN testing using paraffin oilon some specialty blacks and powder blacks may result inunacceptable differences as compared to OAN
9、 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 the oil
10、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 compoundscontaining
11、 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 and Standa
12、rds6.1 Purity of ReagentsReagent grade chemicals shall beused in all tests. Unless otherwise indicated, it is intended that1This test method is under the jurisdiction ofASTM Committee D24 on CarbonBlack and is the direct responsibility of Subcommittee D24.11 on Carbon BlackStructure.Current edition
13、approved Nov. 1, 2011. Published December 2011. Originallyapproved in 1965. Last previous edition approved in 2009 as D2414 09a. DOI:10.1520/D2414-11.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStand
14、ards 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 optimum performance.4Available from C. W. Brabender Instruments, Inc., 50 E. Wesley St., SoutHackensack, NJ 076
15、06 () 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, United States.all reagents shall conform to the specifications of the Commit-tee on Analytical Reagents of the Ameri
16、can Chemical Society,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/m3
17、at 25C and a 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
18、 oils are pharmaceutical or food gradeoil, or both, based on available data.6.4 ASTM D24 Standard Reference Blacks, SRB.67. Sampling7.1 Samples shall be taken in accordance with PracticesD1799 and D1900.8. Calibration and Standardization8.1 Absorptometer:8.1.1 ModelThree different types of absorptom
19、eters are 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 E7), and (3) current model absorptometers which aredesigned with a torque measuring system that inclu
20、des amicro-computer and software to continuously record torqueand oil volume with time (Types H and C and modified TypeE7). Types A, B, and E7are designed to stop mixing at apredetermined, fixed torque level, which is the recommendedprocedure for measuring hard or tread blacks (calibrationProcedureA
21、). The computer controlled models (Types H and Cand modified Type E7) are required for running calibrationProcedure B, the recommended torque curve analysis for thedetermination of the end-point of soft or carcass blacks. TheType H and C and modified Type E7absorptometers can alsoprovide an end-poin
22、t at a fixed or predetermined torque levelsuch that these types of absorptometers are well-suited formeasuring OAN of both hard and soft carbon blacks. Severalcomponents influence the calibration: the dynamometer torquespring or the load cell, the torque limit switch or the indicatorset point, the d
23、amper (oil damper or electronic damping), andthe mixing head consisting of two counter rotating blades anda mixing bowl. It is necessary that all of these components arein good condition and are properly adjusted to achieve accept-able calibration.8.1.2 Mixing BowlTypically the absorptometer is deli
24、v-ered with either a surface-treated stainless steel or anodizedaluminum mixing bowl. These 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 t
25、hebowl should not be modified to achieve calibration.NOTE 2Stainless steel chambers have 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 l
26、ess than 1.5 m (60in.). Stainless steel bowls purchased with an absorptometer have beenpre-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(se
27、e Annex A3).8.2 Calibration:8.2.1 Rotor BladesThe speed of the motor driving therotor blades 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 bure
28、t isto be 4 cm3/min. SeeAnnexA1 for detailed instructions on theprocedure for calibration 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-scaledeflect
29、ion. This is achieved by selecting the appropriate springstrength and adjusting the spring 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
30、be modified in order to achieve a desired level of torque. Ifcalibration is necessary, 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
31、-mended to keep the valve of the oil damper fully closed. TheType B absorptometer shall 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 thatthes
32、e damping options are activated.8.2.5 Torque Limit Switch (TLS) or the Indicator SetPointIf 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-P
33、oint at Fixed Torque LevelThis “classical” method is well suited for most hard or treadblacks but may lead to problems when low-torque carcassblacks are to be tested; proceed to Procedure B for low-torquecarbon blacks. For TypeA, B, and E absorptometers, adjust theTLS or the indicator set point in s
34、uch way that the current SRBF standard gives the correct target value within the limits asdefined in Guide D4821. For Type E, C, and H absorptometers5Reagent Chemicals, American Chemical Society Specifications , AmericanChemical Society, Washington, DC. For suggestions on the testing of reagents not
35、listed by the American Chemical Society, see Analar Standards for LaboratoryChemicals, BDH Ltd., Poole, Dorset, U.K. and the United States Pharmacopeia andNational Formulary, U.S. Pharmacopeial Convention, Inc. (USPC), Rockville, MD.6The sole source of supply of ASTM Standard Reference Blacks known
36、to thecommittee at this time is Laboratory Standards and Technologies, 227 Somerset,Borger, TX 79007, http:/ If you are aware of alternativesuppliers, please provide this information to ASTM International Headquarters.Your comments will receive careful consideration at a meeting of the responsiblete
37、chnical committee,1which you may attend.7Type E absorptometers can be modified with additional hardware and micro-computer system.D2414 112dedicated to testing tread blacks only, there is no advantage tosetting the TLS based on the SRB F standard; for theseabsorptometers, set theTLS to 3500 mNm for
38、DBPoil, or 4000mNm for 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 insufficient torque level. Therefore,the preferred method for testing soft blacks is to record thetorque curve using a chart-re
39、corder 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 disable the automatic shut-off of the absorptometer.8.2.5.3 Procedure C: End-Point at a Fixed, But ReducedTorque LevelRequires us
40、e of SRB-5 series standards. SeeTest Method D2414 00.8.3 Normalization: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 values a
41、re 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 (D,
42、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:Normali
43、zed value 5 measured value 3 slope! 1 yintercept (1)8.3.5 For normalized values of the SRBs that are consis-tently outside the x-chart limits listed in Guide D4821, the testapparatus should be recalibrated in accordance with 8.2.8.3.6 When any absorptometer or calibration changes occur,a new calibra
44、tion 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 oven seta
45、t 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 and D-8 40All others 209.3 It is recommende
46、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
47、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
48、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
49、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 the 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
