Maleic

High reactivity in hot-press molding, process consistency, excellent surface quality (Class A), heat resistance, electrical insulation

Maleic formulations are a type of unsaturated formulations based on Maleic anhydride as sole acid component in combination with different types of glycols (e.g. monopropylene glycol, monoethylene glycol, dipropylene glycol). In the formulation manufacturing process at AOC, these ingredients are combined into an unsaturated polyester chain through a poly-condensation reaction, and then diluted with a reactive monomer (in most cases styrene) and other ingredients to make a finished resin.

Our customers combine the formulation with reinforcements (glass, carbon), fillers and additives into SMC and BMC compounds. When moulding these compounds at elevated temperatures (140-150 °C) a chemical reaction is initiated between formulation backbone and the styrene, transforming the liquid into a hard and durable material.

In Pultrusion processes similar mixtures are used to manufacture profiles and parts with high dimensional accuracy and enhanced surface appearance. Resin formulations can be both with and without fillers.

The Maleic formulations offered by AOC can be easily used in combination with additives like low shrink-additives (LS), low profile-additives (LP) or Class A – additives, providing an excellent functionality in the final application (including low shrinkage effect, dimensional accuracy, surface smoothness and Class A, good pigmentability). 

Through tight process controls in our formulation production a high batch-to-batch consistency is guaranteed, ensuring identical thickening of the formulations when processed into SMC compounds. This translates in a smoothly running SMC molding operation with high level of automatization for the manufacturing of high quality molded parts.

Maleic resins find their way in many applications in Transportation (exterior panels, structural components, and headlamp reflectors), and in Building & Infrastructure (electrical circuit breakers, enclosures, pultruded profiles). Maleic formulations are very reactive, have great heat resistance (Tg around 185°C), are the formulations of choice for Class A surfaces in SMC and BMC. Class A SMC components based on Maleic formulation can resist the temperatures of cataphoresis, and therefore can be in-line coated in automobile manufacturing.

AOC Products

AOC is supplying many formulations based on pure Maleic chemistry under its Palapreg® brand. These formulations have set the industry standard in SMC and BMC already for many years. In order to find the best product for your application, please check out the Product Selector on this web site. You can contact an AOC Technical Service representative for helping you in this process (inquiry.world@AOC.com).

More Information

For an overview of our key products, please consult the Product Selector on this web site, or download the AOC Product Selector Guide.

Please read Blogs on SMC Design, Carbon composites, news on SMC BMC Design Award (editions 2017, 2019), and case study Mercedes Roadster (describing close collaboration Daimler, Menzolit and AOC).