§ Mr. StevensonTo ask the President of the Board of Trade if he will list the non-cadmium substitutes available to replace cadmium pigments in polypropylene following the implementation of European Union directive 91/338/EEC. [12821]
§ Mr. PageThere are many factors to consider when choosing a pigment to colour polypropylene, including the thermal stability of the pigment during processing, the service demands of the finished article—i.e. light and weather fastness—and suitability for use in toys and food contact articles. By assessing the demands of the application, it is then possible to choose the correct pigment for the particular application.
A wide variety of pigments can be used to colour polypropylene, varying in shade, colour, strength, physical properties and price. These include organic systems such as those based on quinacridone, diketo-pyrrolo-pyrrol, isolindolinone, quinophthalone, perylene and azo condensation products. Inorganic systems based upon nickel and chrome titanium and bismuth can also be used.