ASTM D768-01(2007)

This document is not anASTM standard and is intended only to provide the user of anASTM standard an indication of what changes have been made to the previous version. Because
it may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current version
of the standard as published by ASTM is to be considered the official document.
e1
Designation:D768–81(Reapproved 1995) Designation: D 768 – 01 (Reapproved 2007)
Standard Specification for
Yellow Iron Oxide Hydrated
This standard is issued under the fixed designation D 768; 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.
e NOTE—Keywords were added editorially in May 1995.
1. Scope
1.1 This specification covers the pigment commercially known as yellow iron oxide, hydrated.
1.2 The values stated in SI units are to be regarded as the standard. The values given in parentheses are for information only.
2. Referenced Documents
2.1 ASTM Standards:
D 50 Test Methods for Chemical Analysis of Yellow, Orange, Red, and Brown Pigments Containing Iron and Manganese
D 185Test Methods for Coarse Particles in Pigments, Pastes, and Paints Test Methods for Coarse Particles in Pigments
D 280 Test Methods for Hygroscopic Moisture (and Other Matter Volatile Under the Test Conditions) in Pigments
D 1208 Test Methods for Common Properties of Certain Pigments
3. Composition and Properties
3.1 The pigment shall be a manufactured yellow iron oxide obtained by chemical reaction. It shall be a soft, finely powdered
pigment, free of admixtures of other substances and shall conform to the following requirements:
Total hydrated oxide of iron, min, % 93
A
Total oxide of iron, min, % 83
A
Loss on ignition, max, % 13
Moisture and other volatile matter, max, % 1.0
Water soluble matter, max, % 0.50
Coarse particles (total residue retained on a No. 325 0.5
(45-µm) sieve), max, %
Hydrogen ion concentration (pH value) 4.5 to 8.0
__________
A
Total hydrated oxide of iron shall be the sum of iron oxide and loss on ignition. Loss on ignition shall be calculated on the dry material.
3.2 Paste in Oil—The paste in oil shall be made by thoroughly grinding the specified pigment with linseed oil (with or without
a small amount of volatile thinner) together with (where necessary) small amounts of wetting or dispersing agents to a semipaste
or fluid type consistency.As received, it shall not be caked in the container and shall break up readily in oil to form a smooth paint
of brushing consistency. It shall mix readily in all poroportions, without curdling, with linseed oil, turpentine, or volatile petroleum
spirits, or any mixtures of these substances. The paste shall conform to the following requirements:
Pigment, min, % 55
Nonvolatile vehicle, min, % of vehicle 80
Moisture by distillation, max, % 2.0
Coarse particles and skins (total residue retained on a 1.0
No. 325 (45-µm) sieve), max, percent of the dry
pigment
Consistency by the Stormer viscometer:
A
At shearing rate of 100 revolutions/30 s, min, g 700
B
At shearing rate of 100 revolutions/35 s, max, g 1200
__________
This specification is under the jurisdiction of ASTM Committee D-1 on Paint and Related Coatings, Materials, and Applications, and is the direct responsibility of
Subcommittee D01.31 on Pigment Specifications.
Current edition approved March 2, 1981. Published May 1981. Originally published as D768 – 44T. L
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