1. Requirements of color masterbatch coloring materials

The color of the color masterbatch is used for the color material, must be aware of the color material and the plastic raw material, the assistant, the selection of the main points as described below.

(1) color is not suitable for resin and various auxiliaries, strong solvent resistance, small migration, good heat resistance, etc. In other words, the color parent can't participate in various chemical reactions. If carbon black can control the curing reaction of polyester plastic, it cannot be added to polyester.

Due to the high temperature of plastic forming process, the color material should not decompose under the condition of forming heating temperature. Generally, inorganic pigment is good in heat resistance, and the organic pigment and dyestuff have poor heat resistance. This should attract enough attention when choosing the color variety.

(2) the dispersion of the color material and the coloring force should be good. When the color dispersion is uneven, the appearance of the products can be affected. When the color stain is poor, the amount of color will be increased and the material will improve. The dispersion and shading force are not the same in different resins, so you should pay attention to this when choosing the color.

The particle size and dispersion are also related. The smaller the particle size, the better the dispersion and the better coloring power.

(3) other properties of color materials should be understood, such as the use of plastic products in food and children's toys, and the requirement that the color should be non-toxic; The plastic products used in electrical appliances should choose the best color; Used for outdoor plastic products, should choose the weatherproof aging performance good color.

Second, the production process of the color masterbatch

The production process of the color masterbatch is strict, and the wet process is generally adopted. The color masterbatch is made by grinding, rotating, washing, drying and granulating with water. Only in this way can the quality of the product be guaranteed.

Pigment in grinding processing at the same time, also should undertake a series of tests, such as determination of sand slurry fineness, determination of the spread of the abrasive slurry performance, determining the solid content of sand slurry and determination of printing ink fineness, etc.

There are four methods for the process flow of color masterbatch production:

(1) ink method: as the name implies, it is the production method of ink color in the production of the color masterbatch, that is, a layer of low molecular protective coating is covered by three rolls of grinding. After grinding, the pulp is mixed with the carrier resin, then plasticized by a two-roll plastic mixer (also known as a double roll machine), and finally the granulation is made by single screw or double screw extruder.

(2) flushing method: it is the pigment, water and dispersing agent through sanding, so that the pigment particles are less than 1 mu m, and by phase transfer method, the pigment is transferred to the oil phase, and then the color masterbatch is dried. The rotating phase requires the use of organic solvents and corresponding solvent recovery devices. The process is shown in the following diagram: the thin slurry rinses the evaporating concentrated material and the granulation is extruded into the carrier

(3) pinching just: after mixing the pigment with the oil carrier, the pigment is used to make the pigment to be flushed from the water and into the oil. The paint surface is covered by the oil carrier, which can disperse the pigment and prevent the pigment from forming.

(4) metallic soap: paint after grinding granularity reaches 1 mu m or so, and under a certain temperature in soap, make each pigment particle uniform surface wetting by soap, forming a layer of saponification liquid, when metal salt solution adding and saponification layer on the surface of the paint chemical reactions that a layer of metal soap and natural protective layer (magnesium stearate), it makes after grinding fine pigment particles will not cause flocculation phenomenon, and protect certain fineness.

3. Precautions for use of the color masterbatch

(1) after storage for a period of time, the color masterbatch will absorb moisture, especially PET, ABS, PA, PC and so on. Therefore, it is required to dry and reach moisture content according to the same process of ecru grain.

(2) the color masterbatch can be used to achieve the desired brilliance. The color difference and color changes are often taken.

(3) the color masterbatch and other additives will be responsive and should be noticed when used.

(4) the dilution ratio of the color parent grain should be taken care of. The higher dilution ratio, the lower production cost, but also the limitation of processing equipment.