Process for producing coloured polypropylene composition having a high content of beta-modification

摘要

The invention relates to a novel process for producing coloured polypropylenecompositions having a high content of β-modification, wherein polypropyleneis melt blended with at least one inorganic pigment and at least one β-nucleatingagent, wherein a1 ) polypropylene is melt blended with at least one inorganicpigment or with a first concentrate comprising the at least one inorganic pigmentto obtain a coloured polypropylene and a2) the coloured polypropylene is meltblended with at least one β-nucleating agent or with a second concentratecomprising the at least one β-nucleating agent to obtain the colouredβ- nucleated polypropylene composition or b1 ) polypropylene is meltblended with at least one β-nucleating agent or with a second concentratecomprising the at least one β-nucleating agent to obtain a β-nucleatedpolypropylene and b2) the β-nucleated polypropylene is melt blendedwith at least one inorganic pigment or with a first concentrate comprising theat least one inorganic pigment to obtain the coloured β- nucleated polypropylenecomposition or c) a third concentrate is produced by melt blending a first concentratecomprising the at least one inorganic pigment and a second concentrate comprisingthe at least one β-nucleating agent and the polypropylene is melt blendedwith the third concentrate to produce the coloured β-nucleated polypropylenecomposition or d) a first concentrate comprising the at least one inorganic pigmentand a second concentrate comprising the at least one β-nucleating agentare melt blended with the polypropylene to obtain the coloured β-nucleatedpolypropylene composition.