1、Designation: D2414 11 D2414 12Standard 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 n
2、umber 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 oil ab
3、sorption number of carbon black.1.2 The values stated in SI units are to be regarded as the standard. The values given in parentheses are for information only.1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibilityof the use
4、r of this standard to establish appropriate safety and health practices and determine the applicability of regulatorylimitations prior to use.2. Referenced Documents2.1 ASTM Standards:2D1765 Classification System for Carbon Blacks Used in Rubber ProductsD1799 Practice for Carbon BlackSampling Packag
5、ed ShipmentsD1900 Practice for Carbon BlackSampling Bulk ShipmentsD4483 Practice for Evaluating Precision for Test Method Standards in the Rubber and Carbon Black Manufacturing IndustriesD4821 Guide for Carbon BlackValidation of Test Method Precision and Bias3. Summary of Test Method3.1 In this test
6、 method, oil is added by means of a constant-rate buret to a sample of carbon black in the mixer chamber of anabsorptometer. As the sample absorbs the oil, the mixture changes from a free-flowing state to one of a semiplastic agglomeration,with an accompanying increase in viscosity. This increased v
7、iscosity is transmitted to the torque-sensing system of theabsorptometer. When the viscosity of the mixture reaches a predetermined torque level, the absorptometer and buret will shut offsimultaneously. The volume of oil added is read from the direct-reading buret. The volume of oil per unit mass of
8、 carbon blackis the oil absorption number.3.2 Either DBP or paraffin oil is DBP, paraffin or epoxidized sunflower oils are acceptable for use with most standard pelletedgrades of carbon black including N-series carbon blacks found in Classification D1765. OAN testing using paraffin oil on somespecia
9、lty blacks and powder blacksoils or epoxidized sunflower oils on some standard blacks and specialty blacks includingpowder products may result in unacceptable differences as compared to OAN testing using DBP oil. While studies have showneither oil to exhibit comparable precision, paraffin oil offers
10、 the advantage of being non-hazardous; even FDA-approved gradesare available. For either oil, with DBP oil. Paraffin and epoxidized sunflower oils are considered non-hazardous; some paraffin oilsare FDA approved. For any of the oils, Sections 8-11 (Calibration, Procedure, Calculation, and Report) ar
11、e to be consistent withthe oil selected for use. Referee testing between suppliers and users should use DBP oil until such time that precision data areavailable for paraffin oil.alternate oils.4. Significance and Use4.1 The oil absorption number of a carbon black is related to the processing and vul
12、canizate properties of rubber compoundscontaining the carbon black.5. Apparatus35.1 Balance, analytical, with an 0.01-g sensitivity.5.2 Oven, gravity-convection type, capable of maintaining 125 6 5C.5.3 Spatula, rubber, 100-mm.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Co
13、nshohocken, PA 19428-2959. United States15.4 Absorptometer, equipped with a constant-rate buret that delivers 4 6 0.024 cm3/min.45.5 Desiccator.6. Reagent and Standards6.1 Purity of ReagentsReagent grade chemicals shall be used in all tests. Unless otherwise indicated, it is intended that allreagent
14、s shall conform to the specifications of the Committee on Analytical Reagents of the American Chemical Society, wheresuch specifications are available.5 Other grades may be used, provided it is first ascertained that the reagent is of sufficiently highpurity to permit its use without lessening the a
15、ccuracy of the determination.6.2 n-Dibutyl Phthalate, having a density of 1.042 to 1.047 Mg/m3 at 25C and a relative density of 1.045 to 1.050 at 25C.6.3 Paraffn Oil, having a kinematic viscosity of 10 to 34 mm2/s (cSt) at 40C.NOTE 1Three paraffin oils have been found suitable including Marcol 82 fr
16、om Exxon, 80/90 White Oil from Conoco-Phillips, and LC1 oil from LabChemicals, Germany. All three oils are pharmaceutical or food grade oil, or both, based on available data.6.4 Epoxidized sunflower oils, (fatty acid ester, epoxidized) having a density of 0.90 to 0.91 g/cm3 at 20C.66.5 ASTM D24 Stan
17、dard Reference Blacks, SRB.77. Sampling7.1 Samples shall be taken in accordance with Practices D1799 and D1900.8. Calibration and Standardization8.1 Absorptometer:8.1.1 ModelThree different types of absorptometers are in use: (1) early models based on springs and mechanical indicationof torque (Type
18、 A and B), (2) second generation absorptometers equipped with load cells and digital torque display (Type E8), and(3) current model absorptometers which are designed with a torque measuring system that includes a micro-computer and softwareto continuously record torque and oil volume with time (Type
19、s H and C and modified Type E8). Types A, B, and E8 are designedto stop mixing at a predetermined, fixed torque level, which is the recommended procedure for measuring hard or tread blacks(calibration Procedure A). The computer controlled models (Types H and C and modified Type E8) are required for
20、runningcalibration Procedure B, the recommended torque curve analysis for the determination of the end-point of soft or carcass blacks.The Type H and C and modified Type E8 absorptometers can also provide an end-point at a fixed or predetermined torque levelsuch that these types of absorptometers ar
21、e well-suited for measuring OAN of both hard and soft carbon blacks. Severalcomponents influence the calibration: the dynamometer torque spring or the load cell, the torque limit switch or the indicator setpoint, the damper (oil damper or electronic damping), and the mixing head consisting of two co
22、unter rotating blades and a mixingbowl. It is necessary that all of these components are in good condition and are properly adjusted to achieve acceptable calibration.8.1.2 Mixing BowlTypically the absorptometer is delivered with either a surface-treated stainless steel or anodized aluminummixing bo
23、wl. These bowls are considered acceptable provided they give the correct reading for the appropriate SRB referencestandards. The surface finish of the mixer chamber is critical for maintaining proper calibration, and the bowl should not bemodified to achieve calibration.NOTE 2Stainless steel chamber
24、s have been found satisfactory for the test when they are manufactured to a roughness value (Ra) of 2.5 6 0.4 m(100 6 15 in.) based upon 8 measurements. No single measurement should be greater than 3.6 m (140 in.) or less than 1.5 m (60 in.). Stainlesssteel bowls purchased with an absorptometer have
25、 been pre-polished for 16 h to minimize bowl surface changes affecting calibration during their initialuse. It is recommended that new replacement stainless steel bowls should also be pre-polished in the same manner (see Annex A3).8.2 Calibration:1 This test method is under the jurisdiction of ASTM
26、Committee D24 on Carbon Black and is the direct responsibility of Subcommittee D24.11 on Carbon Black Structure.Current edition approved Nov. 1, 2011July 1, 2012. Published December 2011November 2012. Originally approved in 1965. Last previous edition approved in 20092011as D2414 09a.D2414 11. DOI:
27、10.1520/D2414-11.10.1520/D2414-12.2 For referenced ASTM standards, visit the ASTM website, www.astm.org, or contact ASTM Customer Service at serviceastm.org. For Annual Book of ASTM Standardsvolume information, refer to the standards Document Summary page on the ASTM website.3 All apparatus are to b
28、e operated and maintained in accordance with the manufacturers directions for optimum performance.4 Available from C. W. Brabender Instruments, Inc., 50 E. Wesley St., Sout Hackensack, NJ 07606 () and from HITEC Luxembourg, 5 Rue de lEglise,L-1458 Luxembourg (www.hitec.lu).5 Reagent Chemicals, Ameri
29、can Chemical Society Specifications , American Chemical Society, Washington, DC. For suggestions on the testing of reagents not listed bythe American Chemical Society, see Analar Standards for Laboratory Chemicals, BDH Ltd., Poole, Dorset, U.K. and the United States Pharmacopeia and NationalFormular
30、y, U.S. Pharmacopeial Convention, Inc. (USPC), Rockville, MD.6 Two epoxidized sunflower oils have been found suitable including Pionier TP 130C from H this calibration shouldnot be modified in order to achieve a desired level of torque. If calibration is necessary, refer to the instrument manufactur
31、ers recommendations. Theinstrument torque calibration should not be confused with the torque limit switch described in 8.2.5.8.2.4 DamperFor the Type A absorptometer, it is recommended to keep the valve of the oil damper fully closed. The TypeB absorptometer shall provide a full-scale recovery of 3
32、6 0.5 s; the valve has to be adjusted accordingly. The Type Eabsorptometer has an electronic damping option and Types C and H have appropriate software damping. Make sure that thesedamping options are activated.8.2.5 Torque Limit Switch (TLS) or the Indicator Set PointIf the end-point of the test is
33、 determined by a fixed torque limit,the setting of the TLS, also called indicator set-point, has to be selected using one of the following three procedures:8.2.5.1 Procedure A: End-Point at Fixed Torque LevelThis “classical” method is well suited for most hard or tread blacks butmay lead to problems
34、 when low-torque carcass blacks are to be tested; proceed to Procedure B for low-torque carbon blacks. ForType A, B, and E absorptometers, adjust the TLS or the indicator set point in such way that the current SRB F standard gives thecorrect target value within the limits as defined in Guide D4821.
35、For Type E, C, and H absorptometers dedicated to testing treadblacks only, there is no advantage to setting the TLS based on the SRB F standard; for these absorptometers, set the TLS to 3500mNm for DBP oil, or 4000 mNm for paraffin oil.8.2.5.2 Procedure B: End-Point at 70 % of the Maximum TorqueCert
36、ain carcass blacks and thermal blacks may fail to givean end-point due to insufficient torque level. Therefore, the preferred method for testing soft blacks is to record the torque curveusing a chart-recorder or a data acquisition system and to read the end-point at 70 % of the maximum of the torque
37、 achieved. Setthe TLS or the indicator set point to full scale in order to disable the automatic shut-off of the absorptometer.8.2.5.3 Procedure C: End-Point at a Fixed, But Reduced Torque LevelRequires use of SRB-5 series standards. See TestMethod D2414 00.8.3 Normalization:8.3.1 Physically calibra
38、te the test apparatus including TLS adjustment using the instructions in 8.2.8.3.2 Test the six ASTM Standard Reference Blacks (SRBs) in duplicate to establish the average measured value. Additionalvalues are added periodically, typically on a weekly basis. The rolling average of the measured values
39、 is computed from the latestfour values.NOTE 4When only tread- or carcass-type carbon blacks are to be tested, the calibration can be limited to either the three tread- (A, B, C) or the threecarcass-type (D, E, F) carbon black standards.8.3.3 Perform a regression analysis using the standard value of
40、 the standard (y value) and the rolling average measured value(x value). Separate carcass and tread calibration curves should be maintained.8.3.4 Normalize the values of all subsequent samples as follows:Normalized value5measured value3slope!1y 2intercept (1)8.3.5 For normalized values of the SRBs t
41、hat are consistently outside the x-chart limits listed in Guide D4821, the test apparatusshould be recalibrated in accordance with 8.2.8.3.6 When any absorptometer or calibration changes occur, a new calibration curve must be initiated as described in 8.3.2.8.3.7 In most instances, if proper calibra
42、tion cannot be achieved by following 8.2 or 8.3.2-8.3.4, it will be necessary to replacethe mixer chamber with one of proper surface finish.9. Procedure9.1 Dry an adequate sample for 1 h in the specified oven set at 125C. Prior to testing, cool the sample in a desiccator for aminimum of 30 min.9.2 W
43、eigh the sample to the nearest 0.01 g. The recommended 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 recommended that a testing temperature of 23 6 5C be maintained, as measured by a thermocouple in
44、 the mixing bowl.If a temperature controllable mixing bowl is not available, keep the bowl temperature below 30C and comply with Note 5 andNote 6 while running the samples.D2414 123NOTE 5If the absorptometer has remained idle for more than 15 min and a temperature controllable bowl is not being used
45、, a 10-min warm-up samplemust be run before beginning a test. It is important that the mixer chamber temperature be kept uniform. Preferably, allow 5 min between the end of onetest and the start of another.NOTE 6It is important that the temperature of the bowl be the same for machine calibration as
46、for oil absorption testing. ASTM task group work hasshown that an increase in bowl temperature can cause higher values that increased variability in bowl temperatures cause increased test variability.NOTE 7In the event that an endpoint is not obtained (maximum torque TLS) when using an absorptometer
47、 with a fixed TLS such as Type B orE, it is acceptable to mill pelleted carbon blacks using a coarse grinder such as a coffee mill. The carbon black should be milled for only a few secondsto allow sufficient grind time to change the pellets to powder form. High-speed micronizing mills and air-jet mi
48、lls are not acceptable, as they can reducethe carbon black structure.9.4 Transfer the sample to the absorptometer mixer chamber and replace the chamber cover. For Type H, close the safety doorsurrounding the mixing chamber.9.5 Position the buret delivery tube over the hole in the mixer chamber cover
49、, and for Types A, B, or E set the buret digitalcounter 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 absorptometer, activate both “start” buttons simultaneously. The apparatus willoperate until one of the following conditions are met: 1) sufficient torque has developed to activate the torque-limit switch, whichwill halt the absorptometer and buret; 2) the sample torque has reached a maximum and then dropped below maximum tor
