Luminous pigment also called glow-in-the-dark powder because it can absorb light in day and glows in the night. As a special surface treatment material, it can be used in many industry of our daily life. But why some luminous pigment can withstand high temperature and be used as ceramic pigments, while others cannot?

As we know, ceramic pigments need good heat resistance, they are divided into on-glaze color and under-glaze color. The baking temperature of on-glaze color is between 280 degrees and 800 degrees. And the baking temperature of under-glaze color more than 800 degrees, some even exceed 1200 degrees.

In order to reply this question, kindly give us some time to introduce the raw materials of the luminous pigment, Maybe from the perspective of raw materials, we can fully understand the reasons for the different heat resistance of luminous powders of different colors.

At present, there are 2 kinds of luminous pigments produced by raw materials in China, they are rare earth and sulfide.

Strontium aluminate is a mineral purified from rare earths, and it is the raw materials of yellow-green and blue green colors luminous pigment.

Besides strontium aluminate, we can also purified other minerals from rare earths, distinguish from the color of luminescent pigments, the main raw material of sky blue is silicate, purple is calcium aluminate.

Purification requires high temperature firing, so basically the temperature resistance of rare earth luminous powder can basically reach 800 degrees Celsius.

Simply put, yellow green, blue green, sky blue, purple luminous pigment heat resistant reach 800 degrees because their raw materials are mineral purified from rare earths. So these colors luminous pigment can be used for on-glaze paint. From our catalog, we called these 4 colors luminous powder to AS Series.

After repeated purification, we can also get some high purity strontium aluminate, the heat resistance more than 800 degrees, we use these material to produce yellow-green and blue-green luminous powder. So these 2 colors luminous pigment can be used for under-glaze paint, we called these 2 colors luminous powder to AC Series.

In order to meet the color demand on the market, we mixed the fluorescent Pigment with the AS Series, so we got orange-red, orange, blue, green, yellow colors luminous pigment, we called DT series.

But because fluorescent pigments cover the luminous powder, so DT series brightness are lower than AS series.

At the same time, the fluorescent pigments have poor temperature resistance, caused the DT series heat resistance only 200 degrees so we do not recommend DT series for ceramic paints.

If you have the patience to read here, I think you can fully understand the reasons for the different heat resistance of luminous pigments of different colors~~~

In the first sentence of the article, we mentioned that luminous powder can absorb light, Sulfide luminous powder absorbs light faster than rare earth luminous powder, and also releases faster, so sulfide luminous powder is called short-acting luminous powder. Sulfide luminous powder have below colors: Red, orange red, white, purple, orange.

The characteristics of sulfide luminous powder: fast light absorption, round powder particle size, natural waterproof, but low brightness, not environmentally friendly. 

However, sulfide is volatile, and 90% of China's sulfide luminous powder is currently in a stagnant state due to environmental protection.

If you want to know more about luminous pigment, please feel to contact us.