Cristobalite

Introduction

Cristobalite (silica, chemical formula SiO₂) is the result of the calcination of quartz at a temperature of 1500°C.

Cristobalite can be characterised by:

• High brightness
• High purity (low iron content)
• Relatively high Mohs hardness of 6.5
• Relatively low refractive index, making it a transparent filler in various binders.
• Easy wetting
• High inertness in various media
• Transparency for UV-radiation (ie. suitable for UV-curing processes)

Note when using cristobalite: depending on the particle size distribution of the product, it can be labelled (STOT RE 2 or STOT RE 1). For more detailed information, visit www.safesilica.eu.

Basic properties

SIBELITE is the product name for Sibelco’s cristobalite products. SIBELITE M is the product name for antiblock additives for film applications based on Sibelco cristobalite.

The finer SIBELITE grades are mostly used in sealant and adhesives  as an extending filler to reduce formulation cost. They can depending on formulation also have an effect on surface texture, durability (UV resistance), rheology and chemical resistance. Sibelite grades can also be used in UV curing systems.

The majority of the fine grades are labelled STOT RE 2 or STOT RE 1 due to the presence of fine crystalline silica. SIBELITE  M grades are made in dedicated locations which meet the stringent global regulatory requirements. As such our additives have found worldwide regulatory acceptance as so called “indirect food contact additive’s” for plastic film.