ASTM D1648-86(1999)

NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
Contact ASTM International (www.astm.org) for the latest information
Designation: D 1648 – 86 (Reapproved 1999)
Standard Specification for
Basic Lead Silicochromate Pigment
This standard is issued under the fixed designation D 1648; 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.
TABLE 1 Requirements for Pigments
1. Scope
Weight %
1.1 This specification covers two types of pigment commer-
Type 1 Type 2
cially known as basic lead silicochromate.
Regular Particle Size Fine Particle Size
2. Referenced Documents
Min Max Min Max
Lead oxide (PbO) 46.0 49.0 42.5 46.0
2.1 ASTM Standards:
Chromium trioxide (CrO ) 5.1 5.7 6.3 7.2
D 1208 Test Methods for Common Properties of Certain
Silica (SiO ) 45.5 48.5 47.5 50.5
Pigments
Moisture and other volatile mat- . 0.2 . 0.2
ter, % . 0.2 . 0.2
D 1366 Practice for Reporting Particle Size Characteristics
2 Ignition loss at 450 to
of Pigments
550°C, %
D 1844 Test Methods for Chemical Analysis of Basic Lead
Silicochromate
E 20 Practice for Particle Size Analysis of Particulate Sub-
45-μm (No. 325) sieve shall be less than 0.1 %. The maximum
stances in the Range of 0.2 to 75 μm by Optical Micros-
Specific Surface Diameter (SSD) shall be 2.0 μm.
copy
3.4.3 Where closer control within a grade is required, the
fineness requirements shall be as agreed upon by the purchaser
3. Composition and Properties
and the seller.
3.1 Both types of pigment shall consist of silica coated with
lead silicates and lead chromates and shall conform to the
4. Sampling
requirements in Table 1.
4.1 Two samples shall be taken at random from different
3.2 The mass color and character of the tint obtained by
packages from each lot, batch, day’s pack, or other unit of
mixing the pigment with a white pigment shall be the same as
production in a shipment. When no markings distinguishing
that of a reference sample mutually agreed upon by the
between units of a production appear, samples shall be taken
purchaser and the seller.
from different packages, in the ratio of two samples for each
3.3 The oil absorption shall be equal, within agreed upon
10 000 lb (5000 kg), except that for shipments of less than
tolerances, to that of a reference sample agreed upon by the
10 000 lb two samples shall be taken. At the option of the
purchaser and the seller.
purchaser, the samples may be tested separately or after
3.4 Particle Size:
blending in equal quantities the samples from the same
3.4.1 Type 1—This grade is characterized by major amounts
production unit to form a composite sample.
of particles in the 6.5- to 28-μm range. Coarse particles
retained on a 45-μm (No. 325) sieve shall be less than 0.3 %.
5.
...