What is Color Resist?
Color resist is a kind of pigment based ink used in color filters. It is called color “resist” for its resistance towards chemical and physical applications during the manufacturing process. Color resist is also known as resist ink.
Color resist consists of coloring materials (pigments or dyes), polymers, photosensitive materials and solvents. When the ink is exposed to ultraviolet (UV) light, the exposed area becomes insoluble and can resist the etching process. Adding such properties to the ink is a crucial step in manufacturing a color filter.
A color filter consists of a glass substrate coated by three types of color resist (RGB; red, green and blue) in a specific pattern. Since each spot of color resist (sub pixel) is very small, it is difficult to color each dot one by one. Instead, the entire glass substrate is colored and the extra ink is washed away with a developing solution. This process of coloring and removing is repeated three times to complete the RGB pattern.
Here, the property of the color resist helps distinguish the necessary and unnecessary colored areas. As mentioned above, when color resist is exposed to ultraviolet (UV) light, the exposed areas become insoluble and acquires the ability to endure the etching process by the developing solution (This kind of color resist is called a negative resist.) Therefore, by masking the part we want to remove and exposing the part we want to keep, we are able to gain RGB patterns on the glass substrate.
Ingredients of Color Resist
Color resist is manufactured by mixing the mill base, which consists of pigment, resin and solvent, with a photo initiator and various additives for UV triggered polymerization.
Ingredients Color Resist and their Functions
Color Resist of TVS
The color filter materials for FPDs of TVS were developed using the nano-level dispersion technology of the Toyo Ink Group. This technology has been accumulated through the development of printing inks and coating materials. By sufficiently utilizing our strength of being able to develop and produce color resist as well as its ingredients (high-performance pigments), we are contributing to the improvement of color displays.
Refinement and Dispersion Technology of Pigments
FColor materials for electronics such as FPDs require a high transmission ratio of light. In order to achieve this, the technology to refine the pigment particles at nano-level is essential. With this technology, we are able to adjust the pigment size according to various applications.
Making pigment particles disperse uniformly is also essential to improve the transmission ratio. By processing the pigment surface, we are able to stabilize the uniformly dispersed state and avoid any precipitation. With this technology, we are able to provide highly functional color materials with good fluidity (which makes it easier to apply to a substrate) and high transmission, suited for use in electronics.
Development of a New Color (OPTLION® GREEN)
OPTLION® GREEN is a brand-new color material developed by TVS. Currently, we have 2 types, OPTLION GREEN 8880 and OPTLION GREEN 8890. By applying them to a color filter, the real beauty of nature can be reproduced more vividly and brightly. In addition, by applying OPTLION GREEN, the color gamut will be expanded and enhance the color reproduction performance of the display.