Technology and precautions masterbatch production

Pigment masterbatch requirements

Masterbatch pigment used, must pay attention to relations with pigment and plastic raw materials, additives between points below their choice.

(1) pigment and resin and various additives can not be reactive, solvent resistance, migration of small, good heat resistance and the like. That is, the masterbatch can not participate in a variety of chemical reactions. Such as carbon black to control the curing reaction of polyester plastic, it is not added to the carbon black pigment in the polyester.

Due to the high temperature plastic molding process, it should not decompose pigment discoloration at the molding heating temperature conditions. Generally good heat resistance of inorganic pigments, organic pigments and dyes poor heat resistance, this should be taken seriously enough in the choice of pigment varieties.

(2) dispersion, coloring pigment should be good. When the pigment dispersion uneven performance will affect the appearance of the article; coloring pigment is poor, it will increase the amount of pigment, the material cost increases. The same pigment dispersed in various resin and coloring power are not the same, so when selecting a colorant in attention to this.

Toner particle size and dispersion also has a relationship, pigment particle size is smaller, the better dispersion, the coloring is also strong.

(3) should be aware of toner other properties, such as for use in food, children's toys aspect of plastic products, the requirements should be non-toxic pigment; plastic products for the electrical aspects, should choose good electrical insulating toner; plastic products for the outdoor aspect, should choose good resistance to weathering performance pigment and the like.

2. masterbatch production process

Masterbatch production process is very strict, generally use a wet process. Masterbatch material by grinding the aqueous phase, phase, washing, drying, granulation is made, the only way quality can be guaranteed.

Also pigment grinding treatment at the same time, it should also be a series of tests, such as determination of the fineness of sand slurry, measured diffusion properties sand slurry, sand slurry solids content determination and the determination of the fineness of paste and other projects.

Masterbatch material production process, there are four methods:

(1) ink method: As the name suggests, is the use of the ink paste production methods in masterbatch production, namely by three-roll mill, the pigment surface coated with a layer of low molecular weight protective layer. Fine paste after grinding again and the carrier resin is mixed, then by two-roll mill (also called two-roll mill) plasticized, and finally through a single-screw or twin-screw extruder granulation.

The process is as follows:

Ingredients stirring fine coarse paste three-roll grinding paste two roll mill extrusion granulation

(2) Washing method: pigment, water and dispersant through sanding, the pigment particles are smaller than 1μm, and through the phase shift method, the pigment into the oil phase, and then dried to obtain masterbatch. Need to use organic solvents, and when appropriate solvent recovery phase inversion. The process is as follows:

Rinse the evaporator concentrate drying fine paste extrusion granulation added carrier

(3) kneading method: after mixing the pigment and oil carrier, the use of pigment lipophilic this feature, by kneading the pigment from the aqueous phase into the oil phase rinse. While the oil-based carrier coated pigment, the pigment dispersion stability, prevent pigment agglomeration.

(4) metal soap method: After grinding the pigment particle size of around 1μm, and add soap at a certain temperature, so that each pigment particle surface layer evenly wetted soap, forming a layer of liquid saponification, when a metal salt solution was added to the leached layer of the chemical reaction on the surface of the pigment and the layer of metal soap to generate a protective layer (magnesium stearate), so that the pigment particles were milled after not cause flocculation, but some fine protection degrees.

Note 3. The use of masterbatch

(1) masterbatch stored for a period of time will absorb moisture, especially PET, ABS, PA, PC, etc., so according to the same qualities of grain drying processes and achieve moisture requirements.

(2) to achieve the desired color masterbatch mixed colors must be very careful, and often change color and shade may occur.

(3) masterbatch and other additives will react, when used to pay attention.

(4) dilution ratio masterbatch selection should pay attention. Selection of high dilution ratio, the lower production costs, but also limited by the processing equipment.