Pigmented plastics compositions

摘要

A plastics composition comprising a high molecular weight material and an effective colouring amount of an azo pigment of formula where M is Mg, Ca, Sr, Ba or Mn or a mixture of two or more thereof, R<1> and R<2> are chlorine or methyl, x is zero or 1, y is zero or 1 and the sum of x and y is 1, with the proviso that when the high molecular weight material is polyvinyl chloride y is zero.