Performance index of fluorescent pigment
Date:2023-02-17
1. Covering power refers to the ability that when an object is coated with a certain kind of paint, applying the correct paint can cover the background color of the surface of the object to be coated, so that the background color can no longer be exposed through the paint. Covering power=pigment mass (g)/external surface area of coating (CM2)
2. Heat-resistance refers to the fact that the pigment does not have significant changes in color brightness and color strength at a certain processing temperature. It refers to the resistance of pigment to the change of color strength due to processing temperature. It is worth noting that when considering the high temperature resistance of pigments, it is also necessary to consider their heating time.
3. Light fastness refers to the change of color of pigment under light irradiation. The light fastness is evaluated as good as grade 8 zui and inferior to grade 1 Z.
4. Weather resistance refers to the change of pigment to various forms of weather conditions, including visible light and ultraviolet light, moisture and temperature, and product color. After the organic pigment is exposed to light, it will cause the change of pigment molecular structure and other reasons, which will affect the saturation reduction, and even fade to gray or white. The weatherability of the pigment is identified as Grade 5, and Grade 5 is good.
5. Migration resistance refers to the migration of pigments from the inside of plastics to the outside of products or from adjacent plastic products and solvents. In the identification, level 5 indicates no migration, and level 1 indicates serious migration. The specific performance is as follows: ① Frosting: during storage at room temperature, pigment particles migrate from the plastic/pigment system to the surface. ② Solvent exudation: pigment components enter into adjacent solvents, and dyes and some organic pigments show this phenomenon. ③ Contact migration of plastics/plastics.
6. Oil absorption refers to the amount of refined linseed oil absorbed by the pigment sample under the specified conditions, which can be indicated by volume/mass or mass/mass. The amount of oil absorption has a certain impact on the leveling and gloss of the coating.
7. Solvent resistance refers to that after the pigment and solvent contact, because some pigments dissolved in solvent will form solvent staining. Solvent resistance of pigment refers to the function of pigment to form solvent staining due to the dissolution of opposite solvent.
8. Softening point The temperature at which the thermoplastic resin changes from solid state to adhesive state is called softening point. The softening point is too low and the product is easy to agglomerate; If the softening point is too high, the injection temperature must be improved, otherwise the pigment will be difficult to melt and disperse.
9. Differentiation point The resin is destroyed at high temperature, and the temperature of differentiation is called differentiation point. The differentiation point can reflect the thermal stability of the resin.
10. Particle size Particle size is an important target to reflect the particle size of fluorescent pigment, unit: um. The finer the particle size, the more easily the product is dispersed.