MBTO – Monobutyltin Oxide

Versatile, Neutral Catalyst and Stabilizer

Monobutyltin oxide – commonly called MBTO – is an organotin compound. The amorphous, white powder is almost insoluble in water or organic solvents. It can only be easily dissolved in bases / alkalis and mineral acids. MBTO is hydrolytically stable and is used as a versatile neutral catalyst in numerous the chemical industry processes.

NameMonobutyltin Oxide
BNT Product NameBNT-CAT 200
Butyltin oxide
Butylhydroxytin oxide
Butylenestannonic acid

MBTO as a Catalyst

MBTO is primarily used for the production of polyester resins and alkyd resins, in the catalysis of esterification reactions, transesterification reactions and of polycondensation reactions up to 240 °C. The catalyst is integrated into the final product with no impact on quality. As such, processes with Monobutyltin oxide do not require subsequent neutralization or filtering the catalyst out. This makes for a technically simple application process.

MBTO significantly shortens esterification times – 20% to 25% less reaction time when compared to tin-free catalysts – enabling reaction at lower temperatures, saving energy and increasing the efficiency of both process and plants. Another advantage of Monobutyltin oxide is in reducing undesirable side reactions, such as dehydration or oxidative decomposition of polyhydric alcohols

The catalyst can be modified in advance with other ligands and requires no special handling measures, only the avoidance of excessive moisture. The final product is of higher quality in comparison with lithium-based catalysts – offering improved color properties and less haze formation.

The effectiveness of MBTO catalysts is proven for a number of short, medium and long oil alkyds.

Economic Significance of MBTO

Its catalytic properties make monobutyltin oxide an important raw material for the production of unsaturated polyester resins in a variety of applications, such as powder coatings and coil coatings for coating steel and aluminum sheets; for coatings in plastic mold making; and for foils.

It is used as a binder for lacquers and paints and in oleochemistry for various esterification and transesterification products.

Use as Stabilizer

In addition to its use as a catalyst, MBTO can also be used to produce tin stabilizers for various plastics, such as PVC.

Transport and Storage

Monobutyltin oxide is available in various packaging options. It can be stored for at least 6 months in its original sealed packaging without any loss of quality.