The masterbatch consists of an excess of chemical additives, a carrier resin, and a dispersant. The masterbatch is an aggregate obtained by uniformly supporting an excessive amount of a pigment (dye) in a resin.
Main composition of color masterbatch
First, the pigment
Generally divided into organic pigments, such as indigo green; inorganic pigments such as red iron oxide, titanium white; dyes such as reduced pink, orange dispersion and so on. Polyolefins and PVC masterbatches use pigments. Generally speaking, dyes cannot be used for polyolefin coloring, otherwise serious migration will occur.
Primarily, the surface of the pigment is wetted, which is favorable for the further dispersion of the pigment and stabilization in the resin. At the same time, it must be compatible with the resin and does not affect the quality of the coloring product. Polyolefin masterbatch dispersants generally use low molecular weight polyethylene wax or zinc stearate. The engineering plastic masterbatch dispersants generally use polar low molecular weight polyethylene wax, magnesium stearate, and calcium stearate.
Third, the carrier resin
The pigment is evenly distributed and the color masterbatch is in a granular form. The choice of carrier must take into account the compatibility with the pigmented resin, but also consider that the masterbatch should have good dispersibility, so the fluidity of the carrier should be greater than the pigmented resin, and at the same time it will not affect the product quality after being colored. For example, if a polymer with the same melt index is used, the melt index of the masterbatch is higher than that of the polymer, so as to ensure the consistency of the final product. PE, PP color masterbatch LDPE (low density polyethylene) resin as the carrier, PS, ABS masterbatch selected modified PS as carrier.