Effect pigments can be used not only in thermoplastics, but also in cast resins or thermoset plastics. The main field of application is unsaturated polyester resins and PMMA cast resins: Unsaturated polyester resins are used in button production, PMMA cast resins in store fixtures, or for sanitary products such as bath tubs.
The same rule applies for thermoplastic and thermoset polymers when it comes to the use of effect pigments: The more transparent the material, the better the effect works. For cast resins particular attention must be paid to the orientation of the pigments and the settling behavior.
Biflair® – for surfaces that look like liquid metal
Alongside the effect pigments in the Iriodin®, Miraval® and Colorstream® product families a very special effect pigment is used in cast resins: Biflair®. This product series is based on bismuth oxychloride (BiOCl) displays unique luster. Its crystals are so small that the eye is unable to differentiate between the individual particles. In the optical effect they merge together and are reminiscent of metallic surfaces or even liquid metal.
Biflair® pigments are semi-transparent with a silver-white luster and a good coverage, which makes them ideal for mixing with other colored pigments to produce interesting stylings. With a particle size of <15 µm and a platelet thickness of <1 µm, they are some of Merck's smallest effect pigments, promoting low settling behavior, which supports the optimized effect in the cast application, because the pigment will be evenly distributed in the polymer. Their minimum concentration in the polymer system should therefore not be less than 0.4 percent.
For processing powdery effect pigments, such as Iriodin®, Colorstream®, Xirallic®, and Miraval®, in thermoset polymers we offer a paste system: paste fluid A. By adding 30 % pigment to the paste fluid, a formulation is gained that can be used in the same way as Biflair® paste. Alike the Biflair® paste, a minimum concentration of 0.4 % paste fluid into the polymer system should not be underrun, because the paste fluid contains additives which ensure good wetting of the pigments and reduction of the settling behavior.