Overview
EN ISO 3262-17:2024 - Extenders: Precipitated calcium silicate (CEN, ISO/TC 256) specifies requirements and corresponding test methods for precipitated calcium silicate used as an extender/filler. It is part of the ISO 3262 series on extenders and updates earlier editions to define compositional, physical and performance characteristics relevant to coatings, rubber and other industrial applications.
Key topics and technical requirements
This standard sets essential and conditional requirements and references validated test procedures. Major technical points include:
- Composition and oxide limits
- Silica (SiO2) content: minimum 75% (determination by acid digestion/ignition or spectrometry).
- Na2O: 1–5% mass fraction; CaO: 2–24% mass fraction (determined by spectrometric methods).
- Physical parameters
- Residue on 45 µm sieve: max 2% mass fraction.
- Matter volatile at 105 °C: max 10% (ISO 787‑2).
- Loss on ignition: 3–10% (ISO 3262‑1).
- Oil absorption value: min 80 g/100 g (ISO 787‑5 or ISO 19246).
- pH of aqueous suspension: 8–12 (ISO 787‑9).
- Conditional / to be agreed between parties
- Particle size distribution (laser diffraction, ISO 13320).
- Lightness (tristimulus Y) (DIN 53163).
- Specific surface area (ISO 5794‑1).
- Sampling and test reporting
- Representative sampling per ISO 15528; methods require analytical-grade reagents and laboratory-grade water (ISO 3696).
Key test techniques referenced include acid digestion with hydrochloric/sulfuric/hydrofluoric treatment for silica determination, spectrometry for oxide analysis, sieve residue testing, oil absorption measurement, laser diffraction PSD and tristimulus lightness measurement.
Applications
EN ISO 3262-17:2024 is directly applicable to industries that use precipitated calcium silicate as an extender or filler, including:
- Paints and coatings (white/filled pigment systems)
- Rubber compounding and elastomers
- Plastics and polymer fillers
- Paper and board fillers
- Ceramic and adhesive formulations
The standard ensures material quality, batch-to-batch consistency, and suitability for processing and end‑use performance (opacity, rheology, adsorption, pH compatibility).
Who should use this standard
- Quality control and laboratory personnel in pigment/extender manufacturing
- Specification writers and procurement teams for coatings, rubber and plastics
- R&D formulators testing filler performance
- Regulatory and compliance teams referencing material specifications
Related standards
- ISO 3262‑1, ISO 787‑2, ISO 787‑5, ISO 787‑9, ISO 13320, ISO 15528, ISO 3696, ISO 5794‑1, ISO 19246, DIN 53163, ISO 18451‑1
This document provides robust, standardized test methods and acceptance criteria for reliable use of precipitated calcium silicate in industrial formulations.