Masterbatch is a high proportion of additive and thermoplastic resin, pigments or the good dispersion of plastic colorants, it chooses the resin of colorants have good wetting and dispersing effect, and has good compatibility with being shaded material.

So the pigment in the masterbatch is one of the very important components, plastic products easily with oxygen and aging, so often add antioxidants in the machining process. According to the mechanism of antioxidant, it can be divided into main antioxidant, mostly free radical inhibitor - amine and phenolic antioxidants, auxiliary antioxidants (weighing metal passivator) again.

Add antioxidant polypropylene, some pigments and antioxidants will react, thus weakened the function of the antioxidant, make the oxygen thermal stability of polypropylene. Such as phenolic antioxidants easily absorbed by the carbon black or (and) the reaction, and therefore lose activity. So, in coloring products should choose appropriate antioxidant. Color to add antioxidants (phenol) there are three kinds of the influence of the polypropylene.

Serious degradation, slot method of carbon black, single azo red 3 b, ya organism ketone ketoneses magenta, phthalocyanine blue and brown iron oxide yellow;

Moderate degradation, phthalocyanine green, furnace black, ultramarine blue, chrome oxide green;

A slight degradation, chrome yellow, (sulfide) mercury cadmium red, rutile type titanium dioxide.