1、Designation: D 153 84 (Reapproved 2008)Standard Test Methods forSpecific Gravity of Pigments1This standard is issued under the fixed designation D 153; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last revision. A nu
2、mber in parentheses indicates the year of last reapproval. Asuperscript epsilon (e) 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 These test methods cover three procedures for determin-
3、ing the specific gravity of pigments, as follows:Test Method AFor Routine Testing of Several SamplesSimultaneously.Test Method BFor Tests Requiring Greater Accuracy thanTest Method A.Test Method CFor Rapid and Accurate Testing of SingleSamples.1.2 The specific gravity value obtained by these procedu
4、resmay be used with the weight of a dry pigment to determine thevolume occupied by the pigment in a coating formulation.1.3 The values stated in SI units are to be regarded as thestandard. The values given in parentheses are for informationonly.1.4 This standard does not purport to address all of th
5、esafety concerns, if any, 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. For specific hazardstatements, see Sections 5, 11, and 15.2. Referenc
6、ed Documents2.1 ASTM Standards:2D 1193 Specification for Reagent Water3. Purity of Reagents3.1 Purity of WaterReference to water shall be understoodto mean reagent water as defined by Type II of SpecificationD 1193.TEST METHOD AFOR ROUTINE TESTING OFSEVERAL SAMPLES SIMULTANEOUSLY4. Apparatus and Mat
7、erials4.1 PycnometerA pycnometer (Note 1) having a 50-mLcapacity.NOTE 1The Weld type with the cap seal on the outside of the neck ofthe bottle is preferred because there is less danger of trapping air justunder the capillary tube than with types having the ground glass seal onthe inside of the neck.
8、4.2 Water Bath, maintained at 25 6 0.5C and equippedwith a stirring device.4.3 Manometer, open- or closed-tube (see Part f of theapparatus for Test Method C), made of glass tubing 6 mm indiameter, fitted with rubber pressure tubing attached to aT-joint leading to the desiccator and the pump. For the
9、open-tube type 860 mm of mercury shall be used. Thedifference in levels of the mercury in the manometer when thesystem is in operation, subtracted from the barometer readingtaken at the same time, shall be considered the absolutepressure of the system in millimetres of mercury.4.4 Desiccator, glass,
10、 constructed with heavy walls towithstand a vacuum of one atmosphere, and with an opening atthe side.4.5 Vacuum PumpsAlaboratory water vacuum-type pump(Note 2), to remove the greater portion of air in the desiccator,and an oil vacuum-type pump, motor-driven, and capable ofreducing the absolute press
11、ure of the system to 3 mm.NOTE 2The water vacuum pump may be omitted if the rate ofevacuation with the oil pump can be controlled so as to avoid a rapidebullition of entrapped air and possible loss of specimen.4.6 Thermometer, having a range from 0 to 60C, andgraduated in 0.1C divisions.4.7 Weighing
12、 Bottle, wide-mouth cylindrical glass (about 30mm in height and 70 mm in diameter), provided with aground-glass stopper.4.8 Immersion LiquidKerosine has been found to be agood wetting vehicle for most pigments, and shall be usedgenerally as the immersion liquid. Refined, white kerosine of1These test
13、 methods are under the jurisdiction of ASTM Committee D01 onPaint and Related Coatings, Materials, and Applications and are the directresponsibility of Subcommittee D01.31 on Pigment Specifications.Current edition approved Feb. 1, 2008. Published February 2008. Originallyapproved in 1923. Last previ
14、ous edition approved in 2003 as D 153 84 (2003).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 AS
15、TM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.narrow evaporation and boiling range shall be used. With somepigments that are not wetted well with kerosine, other immer-sion liquids such as glycerin, ethylene glycol, tetrahydronaph-thalene, etc.
16、, may be substituted. The liquid must have a lowevaporation rate and narrow boiling range, and the sameprocedure shall be followed as with kerosine. Water is not apreferred liquid because of the possibility of frothing.5. Hazards5.1 Before a desiccator is used for the first time, wrap it ina towel a
17、nd test under an absolute pressure of under 3 mm.Exercise care in handling the desiccator when under vacuum,since a sudden jar may cause it to collapse.6. Standardization of Pycnometer6.1 Fill the pycnometer with freshly boiled water at 23 to24C, gradually bring to 25 6 0.5C, and then dry and weigha
18、s specified in 7.6. Empty the pycnometer, and clean, dry, andreweigh it. Next fill the pycnometer with kerosine at 23 to24C, bring to 25 6 0.5C, dry, and weigh as before. Calculatethe specific gravity, S, of the kerosine at 25/25C as follows:S 5 A/B (1)where:A = weight of kerosine, g, andB = weight
19、of water, g.7. Procedure7.1 DryingDry the pigment, preferably in an electricoven, at 105 6 2C for 2 h.7.2 WeighingTransfer to a clean, dry, weighed pycnom-eter, sufficient sample to form a layer approximately 20 mm (34in.) deep. For black, blue, and lake pigments of low specificgravity, use about1go
20、fsample; for inert crystalline pigments,about 4 g; for opaque white pigments, 7 to 10 g; and for redlead, from 15 to 20 g. Weigh pigments of a hydroscopic naturefrom the weighing bottle.7.3 Number of SpecimensRun all samples at least induplicate.7.4 Addition of KerosineAdd enough kerosine to thepycn
21、ometer to form a clear layer approximately14 in. (6 mm)above the pigment. When necessary, stir the specimen with apolished round-bottom glass rod until completely covered bykerosine, adding more kerosine if necessary. Wash the rod withkerosine, adding the washings to the pycnometer.7.5 Removal of Oc
22、cluded AirPlace the pycnometer in thedesiccator. Close the desiccator and attach to the water pumpuntil the greater part of the air is removed from the system.Complete this procedure within a period of 5 to 10 min. Closethe system with a pinchcock and attach the desiccator to the oilpump for the rem
23、oval of the small amounts of air given off atthe low pressures obtainable with the oil pump. Use themanometer to indicate whether the oil pump is giving theproper vacuum. When the manometer indicates that the abso-lute pressure is 3 mm and constant, cut off the oil pump forshort periods, taking care
24、 that the vacuum does not changematerially due to leakage. At first bubbles of air rise from thepigments very rapidly, then this action gradually decreases andfinally stops. The time required for complete removal of airmay vary from 30 min to 24 h, depending upon the nature ofthe pigment. When no mo
25、re bubbles can be seen, it may beassumed that the occluded air has been removed and that thepigment is thoroughly wet with kerosine. Then slowly admitair to the desiccator by means of the pinchcock.7.6 Filling and Bringing to TemperatureRemove the py-cnometer from the desiccator, fill with kerosine
26、at 24 to 25Ctaking care to add a sufficient quantity to prevent air bubbleswhere the pycnometer is closed, and permit to come to constanttemperature at 25 6 0.5C in the water bath. Carefully stopperthe pycnometer and remove excess kerosine with lens paper.Take the pycnometer out of the bath, allow t
27、o come to roomtemperature, and weigh.8. Calculation8.1 Calculate the specific gravity, S, of the pigment asfollows:S 5P1W 2K1D(2)where:P1= weight of pigment used, g,W = weight of water to fill the pycnometer, g,K1= weight of kerosine added to the pigment, g, andD = specific gravity of the kerosine.9
28、. Precision9.1 Duplicate determinations by this test method should notdiffer by more than 0.02.TEST METHOD BFOR TESTS REQUIRINGGREATER ACCURACY THAN TEST METHOD A10. Apparatus (see Fig. 1 and Fig. 2)10.1 Pycnometer, Water Bath, Manometer, Vacuum Pump,Thermometer, Weighing Bottle, and Immersion Liqui
29、dSeeSection 4; also Fig. 2 (e) and (f ).10.2 Bell Jar, glass, with a two-hole rubber stopper. Into onehole of the stopper shall be fitted a separatory funnel with awell-ground stopcock (Fig. 1 (c), extending into the pycnom-eter. Into the other hole of the stopper shall be fitted a glasstube with a
30、well-ground three-way stopcock (Fig. 2 (d) andconnected with the vacuum pump (Fig. 2 (e). The bell jar shallrest on a sheet of rubber, cemented or vulcanized to a glass oriron plate. With stopcock c closed and stopcock d open to theFIG. 1 Apparatus for Test Method BD 153 84 (2008)2pump, the system s
31、hall maintain an absolute pressure of atmost 3 mm. A desiccator may be used instead of a bell jar.10.3 Bottle, storage, (Fig. 2 (h) for kerosine or otherwetting liquid.11. Hazards11.1 Before a bell jar (or desiccator) is used for the firsttime, test under a vacuum as described in Section 5.11.2 Use
32、a buret stopcock (Fig. 2 (c) that is well groundand lubricated with silicone lubricants or use a PTFE-coatedstopcock.12. Procedure12.1 Place the pycnometer containing the weighed, driedpigment under the bell jar. Close stopcocks c and d, start thevacuum pump, and then gradually open stopcock d to th
33、epump. When an absolute pressure of 3 mm has been attainedand can be maintained, fill the separatory funnel with kerosine,close stopcock d, and gradually open stopcock c, addingsufficient kerosine to cover the pigment. Then stop the pumpand release the suction at stopcock d. Finally, fill the pycnom
34、-eter with kerosine, and complete the test as described in 7.6 andSection 8, under Test Method A.13. Precision13.1 Duplicate determinations by this test method shouldnot differ by more than 0.01.TEST METHOD CFOR RAPID AND ACCURATETESTING OF A SINGLE SPECIMEN14. Apparatus (see Fig. 2 and Fig. 3)14.1
35、Buret, 100-mL, with a 75-mL bulb in the upper part,and with the lower part (25 mL) graduated in 0.05-mLdivisions (see Fig. 3).14.2 FlaskA special 100-mL graduated flask (Fig. 2 (b)with ground-glass stopper. The flask shall be thick enough towithstand an absolute pressure of 1 mm, and shall weighbetw
36、een 50 and 60 g. The neck of the flask shall be graduatedin 0.05-mL divisions between the 99 and 100-mL marks. Thedimensions of the flask shall be as shown in Fig. 2.14.3 StopcocksA tightly ground stopcock (Fig. 2 (c) aspart of buret, a, and a three-way stopcock (Fig. 2 (d)connecting with the vacuum
37、 pump, e. To prevent leakage ofkerosine use a buret stopcock (Fig. 2 (c) that is well groundand lubricated with silicone lubricant or use a PTFE-coatedstopcock.14.4 Vacuum PumpSee 4.5; also Fig. 2 (e). In thisprocedure the oil vacuum pump shall be capable of reducingthe absolute pressure of the syst
38、em to 1 mm.14.5 Manometer, Thermometer, Weighing Bottle, and Im-mersion LiquidSee Section 4; also Fig. 2 (f ).14.6 BottleSee 10.3.15. Hazards15.1 The variations that occur under normal conditions in aroom do not materially affect the specific gravity of a pigment.However, take care that the temperat
39、ure of the liquid aftertransferring to the flask is approximately the same as it waswhen in the buret.15.2 Since in determining both K2and V the tip of the buretand bore of the stopcock plug are empty, no correction is to bemade; but stopcock c must be so well ground that under anabsolute pressure o
40、f 1 mm for 30 min no leakage of kerosineshall take place. The usual sources of error are failure toremove all the air from the pigment, and leaks in the system.Use a minimum amount of rubber tubing in the system and,wherever it is used, coat the joints between rubber and glasswith a melted mixture o
41、f beeswax and rosin.FIG. 2 Apparatus for Test Method CD 153 84 (2008)315.3 In cleaning the flask of kerosine only, a rinsing two orthree times with ether, followed by dry air (dried over sulfuricacid and calcium chloride), is considered sufficient. Whenpigment is also present, remove both pigment an
42、d kerosine andfollow with ether rinses until no more pigment remains. Addsome filter pulp (macerated filter paper) and water (with orwithout glass beads), and shake vigorously. Repeat if neces-sary. Rinse the flask with reagent water, and either dry in anoven, or rinse with alcohol and ether followe
43、d by dry air.16. Standardization of Apparatus16.1 Connect the flask to the buret and the pump by meansof a two-holed rubber stopper. Evacuate the system with theburet stopcock (Fig. 2 (c) closed until the pump maintains anabsolute pressure of 1 mm in the flask. Close the three-waystopcock, d, for 30
44、 s, and again open to the pump. There shallbe no appreciable change in the mercury levels in the manom-eter, indicating that the system beyond stopcock d is tight. Withthe vacuum still maintained, fill the buret from the top withkerosine, adjusting the level to the zero mark with a piece ofcapillary
45、 tubing. Now close stopcock d, and carefully openstopcock c, admitting about 75 mL of kerosine into the flask.Open stopcock d to the air, thus releasing the vacuum in theflask, and fill the flask with kerosine to a definite mark on theneck. Read the buret, calling this reading K2(the volume of thefl
46、ask).317. Procedure17.1 Clean the flask dry, and weigh. Transfer a quantity ofthe dry pigment to be tested to the flask by means of a clean,dry, glass funnel with the stem reaching to the bottom of thebulb. A piece of stiff nickel wire is convenient to push thepowder down the stem. Nearly fill the b
47、ulb of the flask with thepigment, which, however, shall occupy a volume of less than25 mL after all air is expelled. Greater accuracy may beobtained with a large specimen than with a small one. Wipe theinside stem as well as the entire outside of the flask with a cleanpiece of dry, lintless cloth. W
48、eigh the flask and pigment, andcalculate the weight of pigment by deducting the weight of theempty flask. With the buret clean and dry, attach the flask to theevacuating system as shown in Fig. 2. After closing stopcocksc and d, start the pump and carefully open stopcock d to thepump. Continue evacu
49、ation until the pump maintains anabsolute pressure of 1 mm in the flask, or until all the air isremoved from the system. Then fill the buret from the top asdescribed in Section 16, close stopcock d, gradually openstopcock c, and add kerosine until the pigment is covered. Tapthe flask gently to dislodge any air bubbles. Stop the pump,open stopcock d to the air, and fill the flask up to the same markas was obtained in determining its volume. Designate thevolume of kerosine required as V. Read the height of the liquidin the buret to the n
