ASTM D1648-86(2020)

Standard Specification for Basic Lead Silicochromate Pigment

ABSTRACT
This specification covers two types of pigment commercially known as basic lead silicochromate. Both types of pigment shall consist of silica coated with lead licates and lead chromates with mass color and character, and oil absorption equal to that of a reference sample as agreed upon by the purchaser and seller. Specimens shall be sampled, prepared, and undergo chemical analysis to test their conformance with specified compositions of lead oxide, chromium trioxide, silica, and moisture and other volatile matter. Materials shall also be tested for ignition loss, specific surface diameter, and particle loss by microscopic methods.
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.  
1.3 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

General Information

• Status: Published
• Publication Date: 31-May-2020
• ICS: 87.060.10 - Pigments and extenders
• Technical Committee: D01 - Paint and Related Coatings, Materials, and Applications
• Drafting Committee: D01.31 - Pigment Specifications

Relations

• Replaces: ASTM D1648-86(2014) - Standard Specification for Basic Lead Silicochromate Pigment
• Effective Date: 01-Jun-2020
• Refers: ASTM D1366-86(2019) - Standard Practice for Reporting Particle Size Characteristics of Pigments
• Effective Date: 01-Oct-2019
• Refers: ASTM D1208-96(2019) - Standard Test Methods for Common Properties of Certain Pigments
• Effective Date: 01-Jun-2019
• Refers: ASTM D1844-86(2014) - Standard Test Methods for Chemical Analysis of Basic Lead Silicochromate
• Effective Date: 01-Dec-2014
• Refers: ASTM D1366-86(2012) - Standard Practice for Reporting Particle Size Characteristics of Pigments
• Effective Date: 01-Nov-2012
• Refers: ASTM D1208-96(2012) - Standard Test Methods for Common Properties of Certain Pigments
• Effective Date: 01-Nov-2012
• Refers: ASTM D1844-86(2008) - Standard Test Methods for Chemical Analysis of Basic Lead Silicochromate
• Effective Date: 01-Jul-2008
• Refers: ASTM D1366-86(2007) - Standard Practice for Reporting Particle Size Characteristics of Pigments
• Effective Date: 01-Nov-2007
• Refers: ASTM D1208-96(2007) - Standard Test Methods for Common Properties of Certain Pigments
• Effective Date: 01-Jun-2007
• Refers: ASTM D1844-86(2003) - Standard Test Methods for Chemical Analysis of Basic Lead Silicochromate
• Effective Date: 01-Dec-2003
• Refers: ASTM D1366-86(2003) - Standard Practice for Reporting Particle Size Characteristics of Pigments
• Effective Date: 10-May-2003
• Refers: ASTM D1844-86(1999) - Standard Test Methods for Chemical Analysis of Basic Lead Silicochromate
• Effective Date: 10-Jul-1999
• Refers: ASTM D1366-86(1997) - Standard Practice for Reporting Particle Size Characteristics of Pigments
• Effective Date: 10-Nov-1997
• Refers: ASTM D1208-96(2002) - Standard Test Methods for Common Properties of Certain Pigments
• Effective Date: 10-Nov-1996
• Refers: ASTM D1208-96 - Standard Test Methods for Common Properties of Certain Pigments
• Effective Date: 10-Nov-1996

Overview

ASTM D1648-86(2020) - Standard Specification for Basic Lead Silicochromate Pigment defines requirements for two commercial pigment types known as basic lead silicochromate. This internationally recognized standard covers the composition, physical properties, sampling, and testing procedures necessary to ensure consistency and quality of basic lead silicochromate pigments used in coatings, paints, and related applications. ASTM D1648-86(2020) leverages methods and principles developed according to World Trade Organization Technical Barriers to Trade Committee guidelines, offering wide global applicability.

Key Topics

• Pigment Types: The standard specifies two grades:

  • Type 1 (Regular Particle Size): Characterized by a major proportion of particles in the 6.5 to 28 µm range with less than 0.3% of particles coarser than 45 µm.
  • Type 2 (Fine Particle Size): Contains mainly fine particles typically below 1.0–2.5 µm, with less than 0.1% coarser than 45 µm.

• Composition Requirements:

  • Lead oxide (PbO), chromium trioxide (CrO₃), and silica (SiO₂) contents must fall within defined mass percentage limits for each type.
  • Moisture and volatile matter cannot exceed 0.2% for both types.
  • Ignition loss must meet specified parameters when tested at 450 to 550°C.

• Physical Properties:

  • Oil absorption must be comparable to a reference sample mutually agreed upon by buyer and seller.
  • Mass color and tint must match a standard agreed by purchaser and supplier.
  • Specific surface diameter (SSD) is limited based on pigment type.

• Sampling and Test Methods:

  • Random sampling is required from each production unit, with specific ratios based on shipment weight.
  • Chemical analysis uses recognized ASTM methods to verify lead oxide, chromium trioxide, silica, moisture, volatile content, ignition loss, and particle size.

Applications

Basic lead silicochromate pigments are primarily used in the formulation of paints, coatings, plastics, and related products where high tint strength, color stability, and durability are required. Compliance with ASTM D1648-86(2020) ensures that these pigments deliver predictable color performance, consistency across batches, and compatibility with existing manufacturing processes. Typical applications include:

• Architectural and industrial coatings
• Road marking paints
• Protective and anti-corrosive coatings
• High-durability plastic coloration

By adhering to this standard, manufacturers, specifiers, and end-users can ensure pigment quality, meet regulatory requirements, and reduce risks associated with non-conforming materials.

Related Standards

ASTM D1648-86(2020) references several related ASTM standards that may be applicable for comprehensive pigment quality control and testing:

• ASTM D1208: Test Methods for Common Properties of Certain Pigments
• ASTM D1366: Practice for Reporting Particle Size Characteristics of Pigments
• ASTM D1844: Test Methods for Chemical Analysis of Basic Lead Silicochromate
• ASTM E20: Practice for Particle Size Analysis of Particulate Substances in the Range of 0.2 to 75 Micrometres by Optical Microscopy (Withdrawn 1994)

These standards complement ASTM D1648, providing detailed procedures for evaluating and reporting on pigment properties and helping ensure conformity and traceability across the supply chain.

---

Keywords: basic lead silicochromate, ASTM D1648, pigment specification, lead chromate pigment, paint pigment standards, pigment quality, pigment testing, silica pigment, industrial coatings, pigment sampling, pigment analysis

Standards Content (Sample)

This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the
Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
Designation: D1648 −86 (Reapproved 2020)
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 that of a reference sample mutually agreed upon by the
purchaser and the seller.
1.1 This specification covers two types of pigment commer-
cially known as basic lead silicochromate. 3.3 The oil absorption shall be equal, within agreed upon
tolerances, to that of a reference sample agreed upon by the
1.2 The values stated in SI units are to be regarded as the
purchaser and the seller.
standard. The values given in parentheses are for information
only. 3.4 Particle Size:
3.4.1 Type 1—This grade is characterized by major amounts
1.3 This international standard was developed in accor-
of particles in the 6.5- to 28-µm range. Coarse particles
dance with internationally recognized principles on standard-
retained on a 45-µm (No. 325) sieve shall be less than 0.3 %.
ization established in the Decision on Principles for the
Themaximumspecificsurfacediameter(SSD)shallbe8.5µm.
Development of International Standards, Guides and Recom-
3.4.2 Type 2—This grade is characterized by major amounts
mendations issued by the World Trade Organization Technical
of fine-sized particles. In general, the maximum size is
Barriers to Trade (TBT) Committee.
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
2. Referenced Documents
Specific Surface Diameter (SSD) shall be 2.0 µm.
2.1 ASTM Standards:
3.4.3 Where closer control within a grade is required, the
D1208 Test Methods for Common Properties of Certain
fineness requirements shall be as agreed upon by the purchaser
Pigments
and the seller.
D1366 PracticeforReportingParticleSizeCharacteristicsof
Pigments 4. Sampling
D1844 Test Methods for Chemical Analysis of Basic Lead
4.1 Two samples shall be taken at random from different
Silicochromate
packages from each lot, batch, day’s pack, or other unit of
E20 Practice for Particle Size Analysis of Particulate Sub-
production in a shipment. When no markings distinguishing
stances in the Range of 0.2 to 75 Micrometres by Optical
between units of a production appear, samples shall be taken
Microscopy (Withdrawn 1994)
from different packages, in the ratio of two samples for each
5000 kg (10 000 lb), except that for shipments of less than
3. Composition and Properties
10 000 lb two samples shall be taken. At the option of the
3.1 Both types of pigment shall consist of silica coated with
purchaser, the samples may be tested separately or after
lead silicates and lead chromates and shall conform to the
blending in equal quantities the samples from the same
requirements in Table 1.
production unit to form a composite sample.
3.2 The mass color and character of the tint obtained by
5. Test Methods
mixing the pigment with a white pigment shall be the
...