ISO 22553-16:2022

Overview - ISO 22553-16:2022 (Pigment‑binder ratio)

ISO 22553-16:2022 specifies a laboratory test method to determine the pigment‑binder ratio in electro‑deposition coatings (e‑coat). The method quantifies solids composition by measuring ash content and non‑volatile matter to calculate pigment and binder fractions. It is intended for automotive and general industrial applications (e.g., chillers, consumer products, radiators, aerospace, agriculture).

Key topics and technical requirements

• Scope and principle
  • Determines pigment content from ash (residue on ignition) and binder content from non‑volatile‑matter (NV) determinations; pigment‑binder ratio is calculated from these results.
• Apparatus and sample sizes
  • Typical equipment: high‑form porcelain crucible, muffle furnace (600–900 °C for ashing), oven with horizontal ventilation (105 °C ±2 °C), analytical balance (0.001 g), desiccator, crucible tongs.
  • Test portion masses: ash test 2–3 g; NV test (per ISO 3251) 1.0 ± 0.1 g.
• Procedure essentials
  • Ash content: dry sample, ignite to constant mass, calculate ash %; duplicate determinations required. If duplicates differ by >0.2% (absolute) repeat test. Report mean to nearest 0.1% (absolute).
  • Correction factor: pigment content = ash content × product‑specific correction factor (provided by manufacturer) to account for ignition loss and composition of solids.
  • Binder content: determine NV (ISO 3251) using specified heating variations (e.g., 180 °C for 30 min or 105 °C for 180 min), then binder % = NV − pigment %.
  • Final pigment‑binder ratio: mass fraction of pigment divided by binder (reported per Clause 7).
• Reporting and precision
  • No precision data are given in the standard.
  • Test report must identify the coating, reference ISO 22553-16:2022, state the pigment‑binder ratio, note deviations, anomalies and test date.

Applications and who uses it

• Quality control laboratories in automotive e‑coat and industrial coating manufacturers.
• R&D and formulation teams verifying pigment load and binder balance in e‑coat baths.
• Suppliers, specifiers and compliance engineers creating material specifications or investigating bath stability and performance.
• Useful for process control, supplier verification, troubleshooting and comparative testing.

Related standards

• ISO 3251 - Determination of non‑volatile‑matter content (referenced for NV testing)
• ISO 1513 - Sample preparation and examination
• ISO 15528 - Sampling of paints and varnishes
• ISO 4618 and ISO 22553‑1 - Terms, definitions and vocabulary for paints and e‑coats
• Other parts of the ISO 22553 series for electro‑deposition coatings

Keywords: ISO 22553-16, pigment-binder ratio, electro-deposition coatings, e-coat testing method, ash content, non-volatile matter, ISO 3251, automotive coating QC.