What types of color-changing coatings are there? Matters needing attention in color-changing coatings.

Color-changing coatings can be divided into photosensitive color-changing and temperature-changing color-changing, which are mostly used in some mechanical products. Color-changing coatings can bring innovation to our senses, but many people still don't know much about color-changing coatings. Let's take a look at the introduction of color-changing coatings first.

Classification of color-changing coatings

The classification of color-changing coatings can be divided into reversible color-changing coatings and irreversible color-changing coatings according to reversibility.

Reversible color-changing paint: when the temperature drops, it can restore the original color, and the pigment contained is iodide.

Irreversible color-changing paint: when the temperature drops, it can't restore its original color, and the pigments contained are nitrates, sulfates and chlorides of chromium, iron, potassium, sodium, calcium and aluminum. Brush on motors, bearings, boilers and other equipment to indicate temperature and ensure safety.

Principle of color-changing coatings

The photosensitive color-changing type of color-changing paint is that the color changes after being irradiated by ultraviolet rays and sunlight, and when the ultraviolet rays or sunlight are lost, the original color is restored. Its principle is to use the energy of UVA to open the bond of photosensitive molecules and make them jump from low energy level to high energy level. That is, it jumps from invisible light to visible light, resulting in color change.

Color-changing paint is a kind of temperature-sensitive color-changing paint, and its principle is to control the color change by using temperature difference. At a certain pressure and temperature, steam, ammonia and carbon dioxide are released due to thermal decomposition, thus changing the composition and structure of the original material.

Form new substances and take on new colors. Matters needing attention of color-changing coatings

(1) The material with pH value of 7~9 is the most suitable for matrix selection.

(2) The light fatigue of photochromic coatings is caused by excessive exposure to ultraviolet light and high humidity. It is suggested to add light absorbers and antioxidants to increase the light fatigue resistance.

(3) Additives (antioxidant, heat stabilizer, ultraviolet absorber and inhibitor) used in photochromic coatings can improve the light fatigue resistance.

However, the proportion of additives depends on the medium used, and the wrong proportion will accelerate the occurrence of light fatigue. (4) The color-changing paint should be stored in a sealed, dry and dark place to avoid direct sunlight.

(5) Temperature-sensitive color-changing paint has slight effect on skin and respiratory tract, and should be sealed when handling.

The environment during spraying operation should be well ventilated. After the paint is completely dried, it will not have any peculiar smell or * * *, which meets the standards for safe toys and food packaging. The above is the relevant knowledge of color-changing coatings for everyone. Interested friends can look at the above introduction and learn more about color-changing coatings.

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