ASTM D478-02

NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
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Designation: D 478 – 02
Standard Specification for
1
Zinc Yellow (Zinc Chromate) Pigments
This standard is issued under the fixed designation D 478; 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.
TABLE 1 Composition Requirements
1. Scope
Type I Type II
1.1 This specification covers the pigments commercially
Zinc (calculated as ZnO), % 35 to 40 35 to 40
known as zinc yellow (zinc chromate).
Chromium (calculated as CrO ), 41 41
3
1.2 Two types are included:
min, %
A
1.2.1 Type I—High-purity, low sulfate and chloride content.
Sulfates (calculated as SO ), max, % 0.20 3.0
3
A
Chlorides (calculated as Cl), max, % 0.10 0.8
1.2.2 Type II—Regular grade.
Alkaline salts (calculated as K O), max, % 13 13
2
Matter insoluble in acetic acid 0.3 0.3
2. Referenced Documents
(1+9) at 80°C, max, %
Moisture and other volatile matter, max, % 1.0 1.0
2.1 ASTM Standards:
Coarse particles (total residue retained on 1.0 1.0
D 185 Test Methods for Coarse Particles in Pigments,
No. 325 (45-µm) sieve), max, %
2
Pastes, and Paints
A
The maximum percent of sulfates or chlorides given in the table for Type II
D 387 Test Method for Color and Strength of Color Pig-
pigment apply if only one or the other is present (for this purpose amounts of less
3
ments with a Mechanical Muller than 0.05 % shall be disregarded). If both sulfates and chlorides are present, the
sum of the percentages of each divided by its respective maximum permissible
D 444 Test Methods for Chemical Analysis of Zinc Yellow
percentage (3.0 for SO and 0.8 for Cl) shall not exceed 1.0. For example, if a
3
2
Pigment (Zinc Chromate Yellow)
sample contains 1.8 % SO (0.6 of the maximum for sulfates) and 0.3 % chlorides
3
(0.4 of the maximum for chlorides), the sample just conforms to the maximum
requirements of the specification in this respect.
3. Significance and Use
3.1 Zinc yellow is used in rust-inhibiting protective coatings
and metal primers for ferrous and non-ferrous metals.
production in a shipment. When no markings distinguishing
4. Composition and Properties
between units of production appear, samples shall be taken
4.1 Dry Pigment—The pigment shall be a reaction precipi- from different packages in the ratio of two samples for each
10 000 lb (4545 kg), except that for shipments of less than
tate of soluble chromates and a suitable zinc compound and
shall be free of extenders, carbonates, and organic color in any 10 000 lb two samples shall be taken.
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