1、Designation: D 3926 05Standard Test Methods forPercent Solids in Titanium Dioxide Slurries1This standard is issued under the fixed designation D 3926; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last revision. A num
2、ber in parentheses indicates the year of last reapproval. Asuperscript epsilon (e) indicates an editorial change since the last revision or reapproval.1. Scope1.1 These test methods cover the determination of theweight percent of solids in aqueous slurries of titanium dioxidepigments by either the u
3、se of a gravity-convection oven(Method A), infrared radiation moisture analyzer (Method B),or a microwave drying system (Method C).1.2 The values stated in SI units are to be regarded asstandard. No other units of measurement are included in thisstandard.1.3 This test standard does not purport to ad
4、dress all of thesafety 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.2. Referenced Documents2.1 ASTM Standards:2D 1193 Speci
5、fication for Reagent Water3. Summary of Test Method3.1 Oven Method:3.1.1 Slurry is weighed by difference into a tared aluminumfoil dish, dried at 105C in an oven for 1 h, cooled in adesiccator, and weighed.3.2 Infrared Method:3.2.1 Slurry is dried under infrared lamps for a specifiedtime and tempera
6、ture. The results are obtained directly formthe units display panel.3.3 Microwave Method:3.3.1 2 to4gofslurry is placed between two glass fiberpads and dried in a microwave drying system. The results areobtained directly form the units display panel.4. Significance and Use4.1 These test methods are
7、intended as a quick and reliableprocedure for measuring the titanium dioxide pigment contentof aqueous slurries. Included with the pigment content in thepercent solids are the various nonvolatile additives used inpreparing a stable slurry. Because the aluminum and silicaoxide treatments on the more
8、highly treated titanium dioxidepigments may change somewhat with prolonged drying, in theoven method the solids of the slurry are considered dry afterheating at 105C for 60 to 65 min. The high temperatureassociated with the infrared moisture analyzer may also effecta change in the aluminum and silic
9、a oxide treatment on highlytreated TiO2products. Therefore, care in selection of time andtemperature are critical to obtain accurate results with theinfrared method. With the short duration of test associated withthe microwave drying system, overdrying is not a concern.5. Apparatus5.1 Oven Method:5.
10、1.1 OvenLaboratory oven capable of maintaining atemperature of 105 6 2C (Note 1). The oven may be agravity-convection type or an oven with a low velocity, forceddraft. An oven with a high-velocity, forced-draft air change,commonly used for baking finishes, is not suitable.NOTE 1The temperature in th
11、e oven must be constantly monitored.Many older ovens will no longer maintain 6 2C; some will maintain thistolerance for a while but occasionally the thermostat will “stick” and thetemperature will vary considerably.5.1.2 BalanceLaboratory analytical balance, accurate to0.1 mg, with 1-g optical reado
12、ut range for fast weighing.NOTE 2Periodically check the accuracy of the 1-g optical scale of thebalance by use of a known 1-g weight; adjust the balance if needed. Thezero adjustment of the optical scale needs to be checked at least every hourroutinely and immediately if there is any possibility of
13、a spill havingoccurred on the balance.5.1.3 DesiccatorStandard laboratory desiccator utilizingan indicating drying medium.5.2 Infrared Method:5.2.1 Infrared Moisture AnalyzerAutomated moistureanalyzer combining infrared drying technology and a precisionanalytical balance in a single unit.5.3 Microwa
14、ve Method:5.3.1 Microwave Drying SystemA National RecognizedTesting Laboratory (NRTL) approved 630 W microwave dry-ing system with 50 g, 0.1 mg readability internal balance tomeasure moisture/solids from 0.1 to 99.99 %.1These test methods are under the jurisdiction of ASTM Committee D01 onPaint and
15、Related Coatings, Materials, and Applications and are the directresponsibility of Subcommittee D01.31 on Pigment Specifications.Current edition approved July 1, 2005. Published July 2005. Originally approvedin 1980. last previous edition approved in 1999 as D 3926 80 (1999).2For referenced ASTM stan
16、dards, 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 ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken,
17、PA 19428-2959, United States.6. Reagents and Materials6.1 Oven Method:6.1.1 Purity of WaterUnless otherwise indicated, refer-ences to water shall be understood to mean reagent waterconforming to Type II of Specification D 1193.6.1.2 Aluminum Foil DishDisposable aluminum foildishes, approximately 60-
18、mm diameter by 18 mm high, 1 to 2g in weight.6.1.3 Disposable Syringe or DropperDisposable 2 or3-mL syringes or 2 to 5-mL droppers.6.2 Infrared Moisture Analyzer:6.2.1 Sample Holders appropriate for the Infrared MoistureAnalyzer.6.2.2 Disposable Syringe (2 or 3-mL) or Dropper.6.3 Microwave Drying Sy
19、stem.6.3.1 Sample Holders appropriate for the Microwave Dry-ing System.6.3.2 Disposable Syringe (2 to 3-mL) or Dropper.7. Procedures7.1 Method A, Oven:7.1.1 Weigh two new, empty aluminum dishes each to 0.1mg. For each dish, this is W1. With a syringe add 2 mL of waterto each dish.7.1.2 Shake or stir
20、 the slurry sample until it is homogeneousand free of any settle material. If the container is transparent oftranslucent, the absence of settled material sticking to thebottom of the container can be ascertained visually. Otherwiseinsert a spatula or the like to make sure there is no settledmaterial
21、.7.1.3 Immediately withdraw 0.4 to 0.8 g of slurry in a new,empty disposable syringe or dropper. The specified amount canbe estimated by a prior trial in another syringe or dropper. Wipeoff the slurry from the outside of the syringe or dropper with aclean, absorbent paper. Cover the sample bottle. W
22、eigh thesyringe or dropper and slurry to 0.1 mg. This is W2.7.1.4 Transfer the contents of the dropper into one of theweighed aluminum dishes. Add the slurry dropwise, gentlyshaking the dish to disperse the test specimen in the water.When no additional slurry can be transferred from the dropper,rewe
23、igh to 0.1 mg the dropper with any residual materialinside. This is W3.7.1.5 Shake the sample of slurry briefly and withdraw asecond 0.4 to 0.8 g of slurry in another new dropper. Weigh andtransfer contents as in 7.1.3 and 7.1.4 to the second weighedaluminum dish.7.1.6 Place the two dishes and conte
24、nts directly onto themetal shelf in the oven at 105 6 2C for 60 to 65 min. Do notdry in the oven longer than the specified 65 min.7.1.7 Remove the dishes from the oven, cool in the desic-cator for 10 to 60 min, remove one dish at a time, and weighimmediately to the nearest 0.1 mg. This is W4for each
25、 dish. Donot cool longer than 60 min since there is a slight possibility ofan equilibrium moisture exchange between the drying mediumand some dried titanium dioxide pigments.7.2 Method B, Infrared Moisture Analyzer:7.2.1 Follow the manufacturers recommendations for in-stallation, set up, and calibra
26、tion of the analyzer.7.2.2 Determine a time and temperature schedule that pro-duces slurry solids equal to those obtained with Method A,gravity convection oven. Program that schedule into theanalyzer as recommended by the manufacturer.7.2.3 Using a new, empty disposable syringe or dropper,transfer t
27、he required amount of sample from a TiO2slurryprepared as in 7.1.2 to a sample holder appropriate for theanalyzer being used.7.2.4 Follow the manufacturers directions for drying thesample. When the end point is reached, the display will showthe percent solids.7.2.5 Repeat the procedure with a fresh
28、sample of slurry.7.3 Method C, Microwave Drying System:7.3.1 Turn microwave unit on and follow manufacturersdirections on warm-up time if required before running the test.7.3.2 Open unit door and place a pair of glass fiber pads onthe balance pan.7.3.3 Close the door and tare the panels following th
29、emanufacturers instructions.7.3.4 Prepare the slurry sample as in 7.1.2.7.3.5 Open the oven door, remove the sample pads and usea new, empty disposable syringe or dropper to deposit 3 to 4 gof sample onto the rough side of one of the glass fiber pads (3to4gofsample will create a bulls-eye the size o
30、f a quarter).Cover the sample with the other glass fiber pad, making sure toput the rough sides of the two pads together, gently squeeze the2 pads together, and place on the balance pan.7.3.6 Close the microwave drying system door, wait 3 s, andpress RUN.7.3.7 When the end point is reached, the disp
31、lay will showthe percent solids and the elapsed time of the test.7.3.8 Repeat the procedure with a fresh slurry sample, newglass fiber pads, and new disposable syringe or dropper.8. Calculation8.1 Method A, Oven:8.1.1 For each of the duplicate measurements calculate thepercent solids to two decimal
32、places as follows:% Solids 5W42 W1!100W22 W3whereW1= weight of empty aluminum dish, g,W2= weight of dropper plus slurry, g,W3= weight of dropper after discharging slurry into dish,and g,W4= weight of dish and slurry after drying, g.Example:W1= 1.4431W2= 2.0894W3=1.4905 % solids 51.8158 2 1.4431!1002
33、.0894 2 1.4905W4= 1.8158 = 62.238.1.2 Calculate the mean value of the duplicate measure-ments to two decimal places.8.2 Method B, Infrared Moisture Analyzer:D39260528.2.1 % Solids will appear on the display panel. Calculatethe mean value of the duplicate measurements to two decimalplaces.8.3 Method
34、C, Microwave Drying System:8.3.1 % Solids will appear on the display panel. Calculatethe mean value of the duplicate measurements to two decimalplaces.9. Report9.1 Round the calculated (MethodA) or display panel solids(Method B and C) mean value to the nearest 0.1 % and reportas percent solids. This
35、 rounded mean value is considered to beone result.Example: solids 5 62.2 %9.1.1 For Method B, record the time, temperature, slope,and standby temperature conditions.9.1.2 For Method C, record the elapsed time of the test.10. Precision10.1 Method A, Oven:10.1.1 On the basis of an interlaboratory test
36、 of this methodin which 17 operators in 15 laboratories analyzed 8 materialswith solids contents at different levels, the within-laboratorystandard deviation was found to be 0.12 % and the between-laboratory standard deviation was found to be 0.23 %. Basedon these standard deviations, the following
37、criteria should beused for judging the acceptability of results at the 95 %confidence level:10.1.1.1 Two results, each the mean of duplicate determi-nations, obtained by the same operator at different times shouldbe considered suspect if they differ by more than 0.34 %absolute.10.1.1.2 Two results,
38、each the mean of duplicate determi-nations, obtained by operators in different laboratories shouldbe considered suspect if they differ by more than 0.65 %absolute.10.2 Method B, Infrared Moisture Analyzer:10.2.1 On the basis of an interlaboratory test of this methodin which 7 operators in 3 laborato
39、ries analyzed 4 materials withsolids contents at different levels, the within-laboratory stan-dard deviation was found to be 0.12 % and the between-laboratory standard deviation was found to be 0.44 %. Basedon these standard deviations, the following criteria should beused for judging the acceptabil
40、ity of results at the 95 %confidence level.10.2.2 Two results, each the mean of duplicate determina-tions, obtained by the same operator at different times shouldbe considered suspect if they differ by more than 0.35 %absolute.10.2.3 Two results, each the mean of duplicate determina-tions, obtained
41、by operators in different laboratories should beconsidered suspect if they differ by more than 1.34 % absolute.10.3 Method C, Microwave Drying System:10.3.1 On the basis of an interlaboratory test of this methodin which 6 operators in 6 laboratories analyzed 4 materials withsolids contents at differ
42、ent levels, the within-laboratory stan-dard deviation was found to be 0.047 % and the between-laboratory standard deviation was found to be 0.225 %. Basedon these standard deviations, the following criteria should beused for judging the acceptability of results at the 95 %confidence level.10.3.2 Two
43、 results, each the mean of duplicate determina-tions, obtained by the same operator at different times shouldbe considered suspect if they differ by more than 0.14 %absolute.10.3.3 Two results, each the mean of duplicate determina-tions, obtained by operators in different laboratories should beconsi
44、dered suspect if they differ by more than 0.68 % absolute.11. Keywords11.1 nonvolatile content; slurries; solids in titanium pigmentslurries; titanium dioxide slurriesASTM International takes no position respecting the validity of any patent rights asserted in connection with any item mentionedin th
45、is standard. Users of this standard are expressly advised that determination of the validity of any such patent rights, and the riskof infringement of such rights, are entirely their own responsibility.This standard is subject to revision at any time by the responsible technical committee and must b
46、e reviewed every five years andif not revised, either reapproved or withdrawn. Your comments are invited either for revision of this standard or for additional standardsand should be addressed to ASTM International Headquarters. Your comments will receive careful consideration at a meeting of theres
47、ponsible technical committee, which you may attend. If you feel that your comments have not received a fair hearing you shouldmake your views known to the ASTM Committee on Standards, at the address shown below.This standard is copyrighted by ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959,United States. Individual reprints (single or multiple copies) of this standard may be obtained by contacting ASTM at the aboveaddress or at 610-832-9585 (phone), 610-832-9555 (fax), or serviceastm.org (e-mail); or through the ASTM website(www.astm.org).D3926053
