What is a pearlescent pigment?
Pearlescent pigments are usually micas, synthetic or natural that have been coated with titanium dioxide, iron oxide or another metal oxide. Platelets of coated mica can vary in size, shape and thickness. It is the degree of these characteristics along with the thickness of the coating that will determine the color of the pigment. Additionally, thickness and the coarseness of the particles determine the sparkle.
How does the pigment work?
White light is the name given to light that makes up all colors of the spectrum. When we see something as a blue pigment, we are seeing the reflection of blue light. When we see something as a red pigment, we are seeing the reflection of red light.
Mica platelets have a high level of transparency. Meaning white light will pass through the platelet. The titanium dioxide layer as a higher refraction index than the mica and the surrounding. Light is refracted and at the interfaces reflected in different angles. By this phase shift so called interference colors – the main characteristic of a pearlescent effect - are created. Iron oxide shows its typical color even in thin layers on a mica substrate.
Manipulating the metal oxide and its thickness allows formulators to fine-tune the reflection of specific wavelengths of light, creating custom and unique colors. Small changes in the platelet can have a large impact on the pigment and colors that are visible.
What are the pigment characteristics?
In addition to the thickness and type of metal oxide, pearlescent pigments have different and defined characteristics that will determine the color.
- Platelet Size – The size of the mica.
- Particle Size Distribution - a characteristic composition of fine and coarse particles leading to the PSD curve.
- Platelet Orientation – The direction the mica particles are facing.
- Pigment Concentration – The amount of pigment added to the base.
- Film Transparency – Transmission of unobstructed light through the film.
How are they used in Automotive?
Pearlescent pigments are used in the automotive industry to provide an alternative to metallics. These pigments provide a different luster and can create an unlimited variety of colors. These pigments are used in OEM, as they allow for an endless spectrum of colors.
How are they used in Cosmetics?
Pearlescent pigments play an important role in the cosmetics industry. This market is set to grow by nearly 5% by 2022 according to a Happi Magazine article. These pigments are used to add color, shimmer, sparkle and glitter effects to cosmetics.
Synthetic mica is regularly used in the cosmetics industry due to its purity. ECKART’s SYNCRYSTAL, for example, uses synthetic mica to create intense and bold colors while allowing for superior skin feel and outstanding chroma.
How are they used in Plastics?
Some pearlescent pigments have the strength and stability to survive polymer processing. Pearlescents also allow cosmetics manufactures to match packaging to the product within. This creates an environment where the consumer can recognize the color and characteristics of a product by merely looking at the packaging.
Plastics Technology is a great resource for learning more about how pearlescent pigments can be used in almost any resin including PS, PP, PE, PVC, acrylic, styrene block copolymers, and silicone.
Does ECKART offer Pearlescent Pigments?
We do. ECKART is a provider of Pearlescent Pigments for just about every industry. Regardless of your industry, ECKART has a pearlescent that will suit your needs:
Different variations of these products including weather resistant versions for exterior use and their delivery form are available. Selecting the right pearlescent pigments can be difficult. This is why ECKART employs a large technical support staff to help you select the proper formulation. Additionally, we can custom make pigments to suit your needs or color match your existing color palette.