VERFAHREN ZUR HERSTELLUNG VON SCHWACH GEFAERBTEN POLYMERISATEN DES ACRYLNITRILS

摘要

The polymer material, which is based on polyacrylonitrile or a copolymer thereof comprising at least 20% by weight of acrylonitrile and at most 80% by weight of other monomers that are copolymerisable with acrylonitrile, contains a thermostabilising additive comprising a nitroalkane. To produce the polymer material, the acrylonitrile or a mixture thereof with appropriate comonomers is polymerised and the thermostabilising additive is added before or during the polymerisation or allowed to diffuse into the ready-polymerised homo- or copolymer. The effect of the thermostabilising additive can be enhanced by the additional use of an aliphatic thioether. The so protected polymer material is suitable in particular for producing mouldings in a thickness of the polymer material where undesirable temperature-induced discoloration would be particularly noticeable.