ISO 14680-2:2000

Overview

ISO 14680-2:2000 - "Paints and varnishes - Determination of pigment content - Part 2: Ashing method" specifies an ashing (calcination) technique for determining the pigment content of paints, varnishes and related coating materials. The method quantifies the non-volatile solid fraction remaining after controlled evaporation and ignition of a test portion. It is part of the ISO 14680 series alongside the centrifuge (Part 1) and filtration (Part 3) methods.

Key topics and technical requirements

• Scope & limitations
  • Applies to products where inorganic pigments/extenders remain after ashing.
  • Not applicable to materials containing aluminium pigments, organic pigments or dyestuffs, inorganic pigments treated with organics, UV paints, or reactive diluents (these constituents can be lost or altered during ashing).
• Principle
  • Evaporate solvent at (80 ± 2) °C, then ash the residue in a muffle furnace or fast incinerator at about 600–900 °C, or 450 °C when carbonates are present (carbonate presence must be determined separately).
• Apparatus & measurement
  • Porcelain tall-form crucible, muffle furnace/fast incinerator, drying oven with forced horizontal ventilation, desiccator, crucible tongs, analytical balance (0.001 g).
  • Typical test portion ≈ 2 g; crucible heated to constant mass, then sample dried, ashed (commonly ~2 h), and re-heated in 15 min cycles until constant mass is achieved.
• Calculation
  • Pigment content (%) = ((m3 − m1) / m2) × 100
    • m1 = mass of empty crucible
    • m2 = mass of test portion
    • m3 = mass of crucible + residue
• Quality & repeatability
  • Tests performed in duplicate; if duplicates differ by >0.5% (relative to mean), repeat.
  • Repeatability (r) = 2% (within one lab); Reproducibility (R) = 4% (between labs).
• Safety note
  • Solvent vapours can form explosive mixtures - oven ventilation and solvent control are critical.

Applications and typical users

• Useful for quality control, batch verification and comparative analysis of coating materials where inorganic solids dominate.
• Primary users:
  • Paint and varnish manufacturers and formulators
  • Coatings quality-control laboratories
  • Raw material and pigment suppliers
  • Conformance testing and regulatory labs evaluating pigment/extender load
• Helps in product formulation, cost control (pigment volume concentration assessments), and material certification where ashing-suitable pigments are used.

Related standards

• ISO 14680-1: centrifuge method (alternative for pigment content)
• ISO 14680-3: filtration method (alternative)
• ISO 1513: sample examination and preparation
• ISO 15528: sampling of paints and varnishes

Keywords: ISO 14680-2:2000, paints and varnishes, determination of pigment content, ashing method, muffle furnace, pigment content by ashing, paint quality control, ISO testing methods.