LANXESS adds heat-resistant yellow pigments for high-performance polymers

LANXESS has expanded its Colortherm Yellow pigment series for heat-resistant high-performance plastics. Two new inorganic yellow pigments are now on the market, namely Colortherm Yellow 5 and Colortherm Yellow 26. They are based on iron oxide and zinc oxide, respectively, and are specially designed for low-cost coloring in the temperature range of 220°C to 260°C. In the same color space, they have the same high color intensity, providing plastic manufacturers and processors with an excellent compromise between the best-in-class Colortherm Yellow 20 and Colortherm Yellow 30 products. These products are thermally stable. The performance is as high as 300°C.

Thermal stability as a quality factor

Plastics can now be used in applications that were considered impossible a few years ago. High-performance polymers with special physical or chemical properties are increasingly replacing metals, glass and ceramics. They are used for special applications in the vehicle, electronics and process engineering, and medical fields. As technical plastics are used more and more widely in high-tech applications, the requirements for pigments used for coloring are also increasing. In particular, the thermal stability of colorants is becoming a decisive quality factor. As far as organic pigments are concerned, high processing temperatures often lead to accelerated decomposition; however, inorganic substitutes will exhibit color changes at temperatures above 180°C.

For the reliable coloring of high-temperature polymers, LANXESS offers the modular Colortherm Yellow product series. It includes iron oxide pigments Colortherm Yellow 5 and Colortherm Yellow 20 as well as Colortherm Yellow 26, Colortherm Yellow 30 and Colortherm Yellow 3950 ferrite zinc. This series not only covers light and saturated yellow colors, but also orange tones. Therefore, plastic formulations can be easily realized at processing temperatures as high as 300°C.

Due to its special production process, the color strength of Colortherm Yellow 26 and Colortherm Yellow 30 zinc ferrite is 20% higher than similar products. This means that when coloring plastics, the amount of pigment added is correspondingly reduced.

"The special thing about our Colortherm Yellow product line is the high degree of flexibility in pigment selection." said Stefano Bartolucci, Global Market Division Manager, Plastics, Inorganic Pigments Business Unit, LANXESS. Depending on the type of plastic, the pigments used may mean that different levels of thermal stability are required. More precisely, it is sufficient thermal stability. "Taking polyethylene coloring as an example, the pigments used only need to show no color change at a processing temperature of 240°C. However, for applications using polyamide, polypropylene and polyphenylene sulfide, 300°C The right and left thermal stability is essential." Bartolucci explained, "By expanding our Colortherm Yellow special pigment series, we provide processors with the option of choosing the pigments that suit them, depending on the type of plastic to be colored and the necessary Thermal stability is customized," he added.

With its well-equipped plastics technology center, LANXESS is able to provide customers with comprehensive advice on the use of its pigments. Its services also include analysis of thermal stability in customer specific plastic applications. "From sample loading to colorimetric analysis, all necessary modules can be operated through an automated process. This allows us to perform highly specific tests with the highest accuracy," Bartolucci said.