ASTM D1648-86(2014)

This document is not an ASTM standard and is intended only to provide the user of an ASTM 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.
Designation: D1648 − 86 (Reapproved 2008) D1648 − 86 (Reapproved 2014)
Standard Specification for
Basic Lead Silicochromate Pigment
This standard is issued under the fixed designation D1648; 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 (´) indicates an editorial change since the last revision or reapproval.
1. Scope
1.1 This specification covers two types of pigment commercially known as basic lead silicochromate.
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:
D1208 Test Methods for Common Properties of Certain Pigments
D1366 Practice for Reporting Particle Size Characteristics of Pigments
D1844 Test Methods for Chemical Analysis of Basic Lead Silicochromate
E20 Practice for Particle Size Analysis of Particulate Substances in the Range of 0.2 to 75 Micrometres by Optical Microscopy
(Withdrawn 1994)
3. Composition and Properties
3.1 Both types of pigment shall consist of silica coated with lead silicates and lead chromates and shall conform to the
requirements in Table 1.
3.2 The mass color and character of the tint obtained by mixing the pigment with a white pigment shall be the same as that of
a reference sample mutually agreed upon by the purchaser and the seller.
3.3 The oil absorption shall be equal, within agreed upon tolerances, to that of a reference sample agreed upon by the purchaser
and the seller.
3.4 Particle Size:
3.4.1 Type 1—This grade is characterized by major amounts 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 %. The maximum specific surface diameter (SSD) shall be 8.5 μm.
3.4.2 Type 2—This grade is characterized by major amounts of fine-sized particles. In general, the maximum size is essentially
below 1.0 to 2.5 μm. Coarse particles retained on a 45-μm (No. 325) sieve shall be less than 0.1 %. The maximum Specific Surface
Diameter (SSD) shall be 2.0 μm.
3.4.3 Where closer control within a grade is required, the fineness requirements shall be as agreed upon by the purchaser and
the seller.
4. Sampling
4.1 Two samples shall be taken at random from different packages from each lot, batch, day’s pack, or other unit of production
in a shipment. When no markings distinguishing between units of a production appear, samples shall be taken from different
packages, in the ratio of two samples for each 5000 kg (10 000 lb), except that for shipments of less than 10 000 lb two samples
shall be taken. At the option of the purchaser, the samples may be tested separately or after blending in equal quantities the samples
from the same production unit to form a composite sample.
This specification is under the jurisdiction of ASTM Committee D01 on Paint and Related Coatings, Materials, and Applications and is the direct responsibility of
Subcommittee
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