The color masterbatch used must pay attention to the matching relationship between the color masterbatch, plastic raw materials, and additives in terms of technology. The key selection points are as follows.

1. Colorants cannot react with resins and various additives, and have strong solvent resistance, low migration, and good heat resistance.

That is to say, color masterbatches cannot participate in various chemical reactions. Carbon black can control the curing reaction of polyester plastics, so carbon black material cannot be added to polyester.

Color masterbatch technology: Due to the high molding and processing temperature of plastic products, the color should not decompose or change color under the heating temperature conditions.

Generally, inorganic pigments have good heat resistance, while organic pigments and dyes have poor heat resistance. This should be given sufficient attention when selecting color varieties.

2. The dispersion and coloring power of the pigment should be good.

When the color dispersion is uneven, it will affect the appearance performance of the product; When the coloring power of the pigment is poor, it will increase the amount of pigment used and increase the material cost. The dispersivity of the same pigment in different resins is not the same as the color force, so this should be paid attention to when selecting the pigment. The particle size of a pigment is also related to its dispersibility. The smaller the particle size of the pigment, the better its dispersibility and coloring power. The process requirements for color masterbatch technology are very strict, and the generally adopted color masterbatch technology is the wet process. The color masterbatch material is made by water phase grinding, phase transformation, water washing, drying, and granulation, only in this way can the product quality be guaranteed.

There are four methods for the process flow of color masterbatch technology

(1) Color Masterbatch Technology Ink Method: As the name suggests, it is the production method of using ink paste in the production of color masterbatches, which involves coating a low molecular protective layer on the surface of pigments through three roller grinding. The ground fine color paste is then mixed with the carrier resin, and then plasticized through a two roll plastic mixer (also known as a double roll open mill), and finally granulated through a single screw or double screw extruder.

(2) Color masterbatch technology process flushing method: It involves grinding pigments, water, and dispersants through sand to make the pigment particles smaller than 1 μ m. And through the phase transfer method, the pigment is transferred into the oil phase, and then dried to obtain the color master batch. Organic solvents and corresponding solvent recovery devices are required for phase inversion.

(3) Color masterbatch technology kneading method: It is the process of mixing pigments with oil-based carriers, and utilizing the hydrophilic characteristics of pigments to wash the pigments from the aqueous phase into the oil phase through kneading. At the same time, the surface of the pigment is coated by an oily carrier, which disperses and stabilizes the pigment, preventing it from setting.

(4) Color masterbatch technology Metallic soap method: the particle size of pigment after grinding reaches 1 μ M, and add soap solution at a certain temperature, so that the surface layer of each pigment particle is evenly wetted by the soap solution to form a layer of saponified solution. When the metal salt solution is added, it reacts with the saponified layer on the surface of the pigment to form a protective layer of Metallic soap (Magnesium stearate), so that the ground pigment particles will not cause flocculation, but protect a certain fineness.