What is the "Plastic Colorants"?

There are many plastic products around us, such as plastic bottles, stationery, and food containers (trays). These plastic products are not originally colored. Plastics (resin) are nearly colorless (milky-white). Colorants such as pigments are added to produce plastic products in various colors.

There are roughly two methods of coloring: external coloring and internal coloring. External coloring is a method of coloring the surface of plastics. It applies to printing, coating, and plating. Internal coloring is a method of coloring plastics by kneading colorants into them. Unlike external coloring, materials are colored evenly up to the inside, because colorants are mixed with plastics. Colorants used for internal coloring are generically called Plastic Colorants.

Plastic colorants do not just add color to our lives, they are helpful for creating a product's image, as well as improving usability and quality.
The effect of coloring is most noticeable in the decoration. In the case of cosmetics, home appliances, and automobile interiors, skillfully create an impression, such as a sense of luxury and dignity, by devising color and luster depending on the materials.

Coloring also plays a role of identification. Using an example from our daily lives, the lid of plastic bottles for hot drinks is uniformly orange colored. Therefore, we can identify hot drinks immediately. Colors are also specified based on the global standards for clearly identifying products at the time of construction or in the event of emergency such as blue for water pipes, and yellow for gas pipes.
Moreover, colors are used effectively to protect contents. For example, the outside of a product is colored black to shield it from UV rays and prevent the deterioration of its contents.

In the meantime, plastic colorants do not only add color, but play a role in enhancing the functionality of products more directly, known as functional plastic colorants.
For example, automobile bumpers and containers use carbon black as plastic colorants to improve weather resistance (*Resistance to temperature change, wind, and rain.)

Also, it is possible to add such functions as conductivity and antistatic performance to plastic colorants. In the case of products including PCs and testing equipment incorporating precision equipment such as IC chips, even a slight current causes malfunction and breakdown. However, plastic materials that protect them tend to be charged with electricity. You can see it from the dust attracted when you rub a plastic sheet. In this case, it is possible to knead plastic colorants with high conductivity into plastics to release electricity outside, lowering the risk of breakdown.
Other usage examples include the use of white plastic colorants for back sheets of solar cells in order to improve power generation efficiency by reflecting light inside.