ASTM D1135-86(1999)

NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
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Designation: D 1135 – 86 (Reapproved 1999)
Standard Test Methods for
Chemical Analysis of Blue Pigments
This standard is issued under the fixed designation D 1135; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript 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. Scope D 280 Test Methods for Hygroscopic Moisture (and Other
Matter Volatile Under the Test Conditions) in Pigments
1.1 These test methods cover procedures for the chemical
D 1193 Specification for Reagent Water
analysis of blue pigments known commercially as iron blue,
D 1208 Test Methods for Common Properties of Certain
copper phthalocyanine blue, and ultramarine blue.
Pigments
1.2 The analytical procedures appear in the following order:
D 2448 Test Method for Water-Soluble Salts in Pigments by
Sections
Measuring the Specific Resistance of the Leachate of the
IRON BLUE PIGMENTS
Pigment
E 11 Specification for Wire-Cloth Sieves for Testing Pur-
Identification 6
poses
Moisture by the Brabender Moisture Tester 7 and 8
Moisture by Toluene Distillation 9
Water-Soluble Matter by Extraction 10
3. Significance and Use
Water-Soluble Salts by Electrical Conductivity 11
3.1 These test methods are suitable for determining if
Detection of Acid-Insoluble Extenders 1213
Detection of Acid-Soluble Extenders 14 to 17
impurities are present and establishing that the required pig-
Detection of Organic Colors and Lakes 18
ments are present. These test methods may be used for
manufacturing quality control.
COPPER PHTHALOCYANINE BLUE PIGMENTS
Identification 19
4. Purity of Reagents and Water
Moisture and Other Volatile Matter 20
4.1 Purity of Reagents—Unless otherwise indicated, it is
Detection of Basic Dye Derivatives 21
Detection of Other Organic Coloring Matter 22
intended that all reagents shall conform to the specifications of
Detection of Ultramarine Blue 23
the Committee on Analytical Reagents of the American Chemi-
Detection of Iron Blue 24
cal Society, where such specifications are available. Other
ULTRAMARINE BLUE
grades may be used, provided it is first ascertained that the
reagent is of sufficiently high purity to permit its use without
Identification 25
lessening the accuracy of the determination.
Moisture and Other Volatile Matter 26
Water-Soluble Matter 27
4.2 Purity of Water—Unless otherwise indicated, references
Detection of Basic Dye Derivatives 28
to water shall be understood to mean reagent water conforming
Detection of Other Organic Coloring Matter 29
to Type II of Specification D 1193.
1.3 This standard does not purport to address the safety
concerns associated with its use. It is the responsibility of the 5. Preparation of Sample
user of this standard to establish appropriate safety and health
5.1 Mix the sample thoroughly and take a representative
practices and determine the applicability of regulatory limita-
portion for analysis. Reduce any lumps or coarse particles to a
tions prior to use.
fine powder by grinding.
2. Referenced Documents
Annual Book of ASTM Standards, Vol 06.03.
2.1 ASTM Standards:
Annual Book of ASTM Standards, Vol 11.01.
Annual Book of ASTM Standards, Vol 14.02.
Reagent Chemicals, American Chemical Society Specifications, American
These test methods are under the jurisdiction of ASTM Committee D-1 on Paint Chemical Society, Washington, DC. For suggestions on the testing of reagents not
and Related Coatings, Materials, and Applications and are the direct responsibility listed by the American Chemical Society, see Analar Standards for Laboratory
of Subcommittee D01.31 on Pigment Specifications. Chemicals, BDH Ltd., Poole, Dorset, U.K., and the United States Pharmacopeia
Current edition approved March 27, 1986. Published May 1986. Originally and National Formulary, U.S. Pharmacopeial Convention, Inc. (USPC), Rockville,
published as D 1135 – 50 T. Last previous edition D 1135 – 81. MD.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
D 1135
5.2 Grind extracted pigments to pass a No. 80 (180-μm)
sieve. Discard any skins that do not pass through the sieve.
Mix the finely ground pigment thoroughly.
IRON BLUE
(Prussian Blue, Chinese Blue, Milori Blue)
occurs, it is best to filter the alkaline solution, weakly acidify the filtrate
IDENTIFICATION
with HCl (1+1), and add approximately 2 mL of a ferric salt solution
(ferric sulfate or ferric alum (20 g/L)). The formation of a blue precipitate
6. Procedure
established the pigment as consisting, at least in part, of iron blue.
6.1 To approximately 0.1 g of pigment in a 50-mL beaker,
add 15 mL of NaOH solution (50 g/L). Heat to boiling. In a few MOISTURE BY THE BRABENDER MOISTURE
minutes the blue color should be completely destroyed, giving TESTER
in its place the characteristic reddish brown precipitate of ferric
hydroxide. Add HCl (1+1) until faintly acid to litmus. The iron
7. Apparatus
blue should be reformed, yielding again the characteristic blue
7.1 Brabender Moisture Tester—The Brabender moisture
color.
tester (Fig. 1) consists of a constant-temperature oven with
weighing apparatus attached. Specimens placed in the oven
NOTE 1—If the NaOH treatment does not completely destroy the blue
color, the evidence is strong that a foreign pigment is present. If this may be weighed without opening the oven door or removing
FIG. 1 Brabender Moisture Tester
D 1135
the specimen from the oven, as the balance scale is calibrated less than 15 h, shaking from time to time, preferably with an
to read directly in percent of moisture. automatic shaking device.
NOTE 4—Ethyl alcohol denatured with acetone (Formula No. 23A) or
8. Procedure
denatured with methyl alcohol (Formula No. 3A) has been found suitable.
8.1 Set the temperature control at 160°C and allow the oven
10.3 Let settle, filter through a dry filter paper, and discard
to reach this temperature before checking or making any
the first 20 mL of the filtrate. Transfer 100 mL of the clear
weighing. Check the scale by placing a sample dish containing
filtrate to a weighed dish, and evaporate to dryness on a steam
9.200 g standard analytical balance weights in the oven. The
bath. Dry for1hinan oven at 105 6 2°C, cool, and weigh.
apparatus should read 8.0 % moisture. If it does not, adjust to
10.4 Calculation—Calculate the percent of water-soluble
a reading of 8.0 % by turning either the right hand or left hand
matter as follows:
foot screw.
Water2soluble matter, % 5 grams of residue 3 100
8.2 Weight 10.000 g of the sample in the aluminum dish and
place in the oven. For a series of specimens, all should be
WATER-SOLUBLE SALTS BY ELECTRICAL
placed in the oven at as nearly the same time as possible. No
CONDUCTIVITY
specimen should occupy the position directly in front of the
11. Procedure
door. Weigh the specimen at the end of each hour for 5 h. After
11.1 Determine water soluble salt content in accordance
each weighing, return the specimen to its original place in the
with Test Method D 2448.
oven.
DETECTION OF ACID-INSOLUBLE EXTENDERS
NOTE 2—The dried pigment is very hygroscopic. In order to obtain
consistent results, the specimen position must not be changed and the oven
12. Scope
door must not be opened.
12.1 Acid-insoluble extenders include barium sulfate, silica,
8.3 Calculation and Report—Plot time against percent loss
and silicates. Alumina may also be found, in part, with this
in weight on rectilinear cross-section paper. Extrapolate the
group.
linear portion of the curve to zero time. That portion beyond
about 2 h will be essentially linear. Report the percent loss in
13. Procedure
weight at the extrapolated zero time as the percent moisture in
13.1 Ignite about 1 g (weighed to 0.1 mg) of the sample at
the pigment.
a low temperature, just enough to decompose the last trace of
pigment but not high enough to render the iron difficultly
NOTE 3—The pigment undergoes a slight loss in weight due to
decomposition during the heating. The method of plotting and extrapola- soluble in HCl (Note 5). Cool, and add 15 mL of HCl (sp gr
tion corrects for this loss. An approximate value for moisture content may
1.19) and a few drops of bromine. Cover with a watch glass
be obtained by taking the reading at the end of the first hour’s heating. An
and evaporate to a sirup. Add about 15 mL of water, and boil.
occasional pigment may decompose rapidly at the oven temperature. In
It may be necessary to add a drop or two of HCl to effect
such cases, determine moisture by the toluene distillation method (Section
complete solution of the ferric iron residue. Filter and wash
9).
with hot water. Save the filtrate for the determination of
MOISTURE BY TOLUENE DISTILLATION alumina hydrate (Section 16).
NOTE 5—The ignition can conveniently be carried out in a 250-mL
9. Procedure
beaker or a porcelain dish over a free flame. Oxidation of the specimen is
evidenced by a dull glowing. While being heated, it is advisable to roll the
9.1 Determine the moisture content in accordance with
specimen around in the beaker or dish exposing all of the surface to the
Sections 7 and 8 of Test Method D 1208, but using 25 g of
oxygen of the air. A moderately low flame should be used and the ignition
pigment and 200 mL of toluene and adjusting the calculation
is complete when the specimen ceases to glow and acquires a uniform
accordingly.
brown color.
13.2 A residue of less than 3 mg that appears as small black
WATER-SOLUBLE MATTER BY EXTRACTION
specks can be neglected, since quite frequently a small amount
10. Procedure of iron is rendered insoluble or a small amount of blue pigment
escapes destruction. Ignite the residue and weigh. If apprecia-
10.1 Determine whether or not the pigment is easily wet by
bly more than 3 mg are present, extenders should be suspected,
water at room temperature by adding a little to some water in
and if it is required to know which extenders are present,
a beaker. If it tends to float on top of the water with very little,
analyze the residue for silica, barium sulfate, and alumina.
if any, tendency to sink to the bottom or disperse throughout
the solution, even after agitation, it contains a hydrophobic
NOTE 6—If alumina is present, it may appear both with the acid-
insoluble and acid-soluble extenders. As a rule, most of it will appear with
treating agent.
the acid-soluble extenders.
10.2 Weigh to 1 mg about 2.5 g of the pigment into a
250-mL volumetric flask. If
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