ARALDITE® PT 912

• The chemical structure/composition of ARALDITE PT 912 has been designed so as to match the technical properties of ARALDITE® PT 810, thus easing the reformulation of prior art powder coating products. As one of the main differences, the epoxide groups of ARALDITE® PT 912 are glycidylesters, which translates in a more favourable labelling status in the European Union. When combined with a polyester resin, ARALDITE® PT 912 provides a gel time, which is on average ca. 30% shorter than when ARALDITE® PT 910 is used. An additional advantage resulting from the enhanced functionality of ARALDITE® PT 912 consists of the increased crosslink density of the cured coatings. The combination of increased reactivity and crosslink density ensures more quality consistency, especially for products with demanding technical profile.
• General coating properties: Polyester / ARALDITE® PT 912 coatings exhibit a very compact structure. Owing to the pure addition mechanism of the crosslinking reaction, no volatiles are released; therefore coatings are obtained, which are free of pores and voids of any kind. Such coatings can be processed without any severe cure window or film thickness limitation. There is no lack of adhesion, e.g. between coating layers (re-coatability) or with sealants. When formulated with suitable polyester resins, ARALDITE® PT 912 supplies a very attractive and consistent product quality profile including storage stability, appearance, curability and over bake stability (especially in gas fired ovens).

ARALDITE PT 912 is an epoxy resin consisting of a glycidylester mixture, designed as hardener for the formulation of weatherable powder coatings. It offers an alternative high quality epoxy crosslinker to ARALDITE® PT 810 with enhanced functionality vs. ARALDITE® PT 910. It can be used in combination with carboxyl-terminated oil free polyester or acrylic resins.

A very intensive homogenisation of the binder components upon premixing and extrusion processing is required to achieve the desired product quality. Due to the large viscosity gap
between ARALDITE® PT 912 and the suitable polyester resins in the typical extrusion temperature range, i.e. 90-140°C, a relatively high shear is needed to ensure a homogeneous mixture.
Single-screw as well as twin-screw extruders are suitable. Screw configuration and extrusion parameters are to be set according to the manufacturer’s guidelines. Please do not hesitate to seek advice from Huntsman’s technical service. The grinding step is made in similar conditions as for TGIC containing formulations. Owing to the strong relaxation, which takes place in a freshly made Polyester/ARALDITE® PT 912 powder, it is particularly advisable to blend silica or aluminium oxide anti-caking additives in order to ensure powder fluidity upon storage at elevated temperature.

Wear suitable protection gloves and safety glasses. If contact with skin occurs, wash immediately with plenty of soap and water. Forced ventilation, local extraction and personal measures, such as dust masks or respirators should be used in order to ensure that operatives do not breath in dust generated by resin, hardener or formulated powder coatings.

ARALDITE® PT 912 should be stored in a dry place, preferably in the sealed original container, at temperatures between 2 and 18 °C. The product should not be stored exposed to direct sunlight, and pallets should not be pilled up. Temperatures above 18 °C during storage and transport can result in backing of flakes. This effect can make handling more difficult, but does not change the chemical structure of the product.Shelf life (at storage temperature between 2 - 18 °C) (see expiry date on original container) 2 years