The Inorganic Pigments (IPG) business unit of Lanxess is supporting masterbatch producers with recommendations regarding the maximum pigment concentration of iron oxide pigments of the Colortherm brand in so-called bioplastic formulations with a low heavy-metal content.

Due to regulated heavy-metal levels, certain pigment classes cannot be used for coloring biodegradable plastics made from renewable or fossil resources. This is the case with, for example, nickel-, chrome- or copper-based pigments.

“Our Colortherm iron oxide pigments are ideally suited to the task of coloring compostable plastics. The decomposition of the polymer is not affected,” says Stefano Bartolucci, Global Market Segment Manager for Plastics at IPG. “Based on the recommended pigment dosing, masterbatch producers can instantly develop individual formulations for colored biodegradable plastics – no expensive pigment screening is required,” says Bartolucci.

The Colortherm-brand iron oxide pigments have been proven to be almost completely free from heavy metals. As a result, the limits for biodegradable plastics can be reliably maintained, even with a high pigment content. The Colortherm iron oxide pigments are available in red, yellow, brown, and black and also in numerous intermediate tones. They do not require special labeling, nor are they classified as hazardous substances. Their reportedly consistent high product quality is achieved through the systematic use of controlled raw materials combined with continuous quality controlling.

The inorganic pigments from LANXESS are widely used in the coloration of plastics for a broad range of applications. “Our pigments can enhance the properties of plastics, make them more cost-efficient, and increase flexibility in production. Our application specialists can also help customers all over the world find solutions to their challenges,” says Bartolucci. The company runs a global network of state-of-the-art laboratories and technical application facilities.