1、Designation: D 153 84 (Reapproved 2003)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:D 1193 Specification for Reagent Water23. 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 PumpsA laboratory 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 pres
11、sure 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 Weighin
12、g 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 ofnarrow eva
13、poration 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., may be substituted. The liquid must have a lowevaporation rate and narrow boiling range, and the sameprocedure
14、 shall be followed as with kerosine. Water is not apreferred liquid because of the possibility of frothing.1These test 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 Pigmen
15、t Specifications.Current edition approved May 10, 2003. Published June 2003. Originallyapproved in 1923. Last previous edition approved in 1984 as D 153 84 (1996)e1.2Annual Book of ASTM Standards, Vol 11.01.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 1942
16、8-2959, United States.5. Hazards5.1 Before a desiccator is used for the first time, wrap it ina towel and 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
17、pycnometer with freshly boiled water at 23 to24C, gradually bring to 25 6 0.5C, and then dry and weighas 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 grav
18、ity, S, of the kerosine at 25/25C as follows:S 5 A/B (1)where:A = weight of kerosine, g, andB = weight 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 ap
19、proximately 20 mm (34in.) deep. For black, blue, and lake pigments of low specificgravity, use about1gofsample; 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
20、of SpecimensRun all samples at least induplicate.7.4 Addition of KerosineAdd enough kerosine to thepycnometer 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 ke
21、rosine if necessary. Wash the rod withkerosine, adding the washings to the pycnometer.7.5 Removal of Occluded 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 perio
22、d of 5 to 10 min. Closethe system with a pinchcock and attach the desiccator to the oilpump for the removal 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 indicat
23、es that the abso-lute pressure is 3 mm and constant, cut off the oil pump forshort periods, taking care 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 c
24、omplete removal of airmay vary from 30 min to 24 h, depending upon the nature ofthe pigment. When no more 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
25、.7.6 Filling and Bringing to TemperatureRemove the py-cnometer from the desiccator, fill with kerosine 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 stoppe
26、rthe pycnometer and remove excess kerosine with lens paper.Take the pycnometer out of the bath, allow to 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
27、pycnometer, g,K1= weight of kerosine added to the pigment, g, andD = specific gravity of the kerosine.9. 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.
28、2)10.1 Pycnometer, Water Bath, Manometer, Vacuum Pump,Thermometer, Weighing Bottle, and Immersion LiquidSeeSection 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),
29、 extending into the pycnom-eter. Into the other hole of the stopper shall be fitted a glasstube with a 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
30、c closed and stopcock d open to thepump, the system shall 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, te
31、st under a vacuum as described in Section 5.FIG. 1 Apparatus for Test Method BD 153 84 (2003)211.2 Use 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 unde
32、r the bell jar. Close stopcocks c and d, start thevacuum pump, and then gradually open stopcock d to thepump. 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
33、to cover the pigment. Then stop the pumpand release the suction at stopcock d. Finally, fill the pycnom-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.TE
34、ST METHOD CFOR RAPID AND ACCURATETESTING OF A SINGLE SPECIMEN14. Apparatus (see Fig. 2 and Fig. 3)14.1 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
35、 stopper. The flask shall be thick enough towithstand an absolute pressure of 1 mm, and shall weighbetween 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
36、stopcock (Fig. 2 (c) aspart of buret, a, and a three-way stopcock (Fig. 2 (d)connecting with the vacuum 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
37、(e). In thisprocedure the oil vacuum pump shall be capable of reducingthe absolute pressure of the system 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 i
38、n aroom do not materially affect the specific gravity of a pigment.However, take care that the temperature 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 em
39、pty, no correction is to bemade; but stopcock c must be so well ground that under anabsolute pressure of 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
40、 in the system and,wherever it is used, coat the joints between rubber and glasswith a melted mixture of beeswax and rosin.15.3 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
41、. Whenpigment is also present, remove both pigment and 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 d
42、ry in anoven, or rinse with alcohol and ether followed by dry air.FIG. 2 Apparatus for Test Method CD 153 84 (2003)316. 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 un
43、til the pump maintains anabsolute pressure of 1 mm in the flask. Close the three-waystopcock, d, for 30 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,
44、fill the buret from the top withkerosine, adjusting the level to the zero mark with a piece ofcapillary 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 w
45、ith kerosine to a definite mark on theneck. Read the buret, calling this reading K2(the volume of theflask).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
46、 thebulb. A piece of stiff nickel wire is convenient to push thepowder down the stem. Nearly fill the bulb 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. Wip
47、e theinside stem as well as the entire outside of the flask with a cleanpiece of dry, lintless cloth. Weigh 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.
48、After closing stopcocksc and d, start the pump and carefully open stopcock d to thepump. Continue evacuation 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
49、, 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 nearest estimated 0.01 mL.18. Calculation18.1 Calculate the specific gravity, SG, of the pigment asfollows:SG 5 P2/ K22 V!where:P2= weight of pigment used, g,K2= volume of kerosine required to fill t
