ATH

Introduction

ATH (aluminium trihydrate, chemical formula Al(OH)₃) is an intermediate product of aluminium production, characterised by: 

• High purity
• High whiteness
• Relatively low density of 2.4 g/cm³ compared to other mineral fillers, which are typically at 2.7 g/cm³
• Medium Mohs Hardness of 3
• Decomposition around 200°C, releasing water. 

Basic properties

Portaflame SG is the product name for Sibelco’s milled ATH-based products.

Portaflame SG  is the product name for Sibelco’s milled ATH-based products. Portaflame SG is used as a flame retardant mineral in a wide variety of applications. Moreover, Portaflame SG products are used to increase the thermal conductivity of polymer based composites.  Depending on processing conditions and requirements for the final application  6 different subgroups have been developed to meet the expectations of the formulator, converter /applicator and end-customer. They are a cost-effective replacement for precipitated ATH.

Additional benefits when using Portaflame SG:

• Chemical resistance: due to its inert nature, ATH provides good chemical resistance compared to conventional fillers.
• Low abrasion due to its low hardnesss of 3 on the scale of Mohs.
• UV-curing compatibility: being transparent for UV radiation, ATH does not block the curing mechanism

Product variants

PORTAFLAME SG

Sibelco’s Portaflame SG product-range consists of products with a defined PSD, topcut, colour, oil absorption, chemistry and BET. These products are typically used in applications where easy handling of the product and economics are important. Portaflame SG provide effective flame-retardant properties by releasing water above 180 °C and by producing an insulating char, whilst the particle morphology ensures good processability. This optimal combination of properties makes these materials ideal mineral fillers for wide range of matrixes. We offer a broad range of particle sizes with D50 ranging from 2.3 up to 120 µm.

PORTAFLAME SG-E

Engineered from aluminium trihydrate, PORTAFLAME™ SG-E is an excellent conductor of heat whilst being electrically non-conductive and flame retardant. Specially developed for applications with even higher demands for electrical insulation. Sibelco’s Portaflame SG-E products offer a steep PSD, low specific surface area and low moisture making them highly suitable for moisture sensitive formulations. Such range of products will offer an outstanding performance as coarse component in bi- or tri- modal filler systems.

PORTAFLAME SG-LV

Sibelco’s Portaflame Low Viscosity ATH-range consists of products optimized for low oil absorption values. By dedicated milling particle shape and PSD are optimized for optimal packing performance. With Sibelco’s Low Viscosity products the formulator can achieve higher filler loading levels in different resin systems. Portaflame SG-LV product are well suitable to be combined with a Portaflame SG-E product as coarse component to create optimized packing system that offer improved thermal conductivities, dimensional stability and flame retardancy at high filling levels (> 80 w%).

PORTAFLAME SG-LSA

Sibelco’s Portaflame Low Surface Area (LSA) product range consists of fine ATH products with defined top-cut combined with low content of ultrafines and, therefore, reduced surface area. Specially developed for HFFR formualtions as replacement for fine precipitated ATH.

PORTAFLAME SG-S

Sibelco’s Portaflame SG-S Surface-treated range of products are coated with specific agents providing different features such as reactivity, compatibility or hydrophobicity. As a result, these surface treatments provide special rheological features, shorter mixing times, easy dispersability, improved weatherabiltiy and sedimentation stability. In addition, hydrophobically surface treated grades can extend the shelf-life of moisture sensitive polymeric matrixes.

PORTAFLAME SG-X

Sibelco’s Portaflame SG-X are bimodal grades produced from carefully selected synthetic aluminum hydroxide (ATH) optimized for sedimentation behaviour and prevention of segregation during pneumatic handling . These products are used in applications where heat-dissipation and fire-retardancy are critical, for example in thermal interface materials (including electronic vehicle battery heat management), casting resins for power transformers and in potting and encapsulating materials for electric and electronic applications.