Overview
ISO 7143:2007 / EN ISO 7143:2007 - Binders for paints and varnishes - specifies standardized methods of test for characterizing water-based binders (aqueous polymer dispersions and solutions). It covers the test framework and a core set of physical and chemical properties used to describe binders supplied as raw materials for water‑based coating systems. The choice of tests depends on whether the binder is intended for a drying or a curing system.
Key topics and requirements
- Sampling: take a representative sample as described in ISO 15528 before testing.
- Test reporting: reports must reference ISO 7143:2007 and include product identification, methods used, results, deviations and test dates.
- Characterizing properties and corresponding test methods (Table 1 highlights):
- Viscosity - ISO 3219
- Non‑volatile matter - ISO 3251
- pH value - ISO 976
- Sieve residue (gross particle and coagulum) - ISO 4576
- Minimum film‑forming temperature (MFFT) - ISO 2115
- Glass transition temperature (Tg) - ISO 16805 (and ISO 11357/11359 references for DSC/TMA techniques)
- Density - ISO 2811-1
- Residual monomers - ISO 13741-1 / ISO 13741-2
- MEQ value (neutralization equivalent) - ISO 15880
- Molecular mass (GPC) - ISO 13885-1 (results are relative; require common reference samples for comparability)
- Particle size distribution - to be agreed between interested parties (note results can vary strongly with method such as PCS)
- Important caveats: particle size and GPC/molecular mass values are method‑dependent and only reliably comparable when laboratories use common reference materials and harmonized procedures.
Applications and users
- Intended for manufacturers of binders, paint and varnish raw‑material suppliers, and coating formulators for:
- Quality control and batch release testing
- Raw‑material specification and supplier qualification
- R&D and formulation optimization (e.g., tuning MFFT, Tg, viscosity)
- Regulatory and safety dossiers where binder characterization is required
- Also used by independent testing laboratories and certification bodies that perform standardized binder analyses.
Related standards
Key referenced standards (normative) include:
ISO 7143:2007 provides a concise, standardized test matrix for characterizing water‑based binders used in modern coatings, supporting consistent quality control, product specification and communication between suppliers and formulators.
