Abstract: A process is described for the modification of polymer melts by means of finely divided inorganic solid particles (melt modification process), in which a powdery additive which contains the inorganic solid particles with a maximum particle size of 1 ?m embedded in finely divided form in a matrix of an organic substance, the organic substance containing one or more of the substances from the group consisting of polyols, polyglycols, polyethers, dicarboxylic acids and derivatives thereof, AH salt, caprolactam, paraffins, phosphoric acid esters, hydroxycarboxylic acid esters and cellulose, is incorporated into the polymer.

Abstract: A processing aid for further processing in synthetic polymers comprising finely divided, inorganic pigments and/or fillers. Such processing aids can homogeneously be dispersed with little effort when the same are embedded in an organic substance.

Abstract: A process is described for the modification of polymer melts by means of finely divided inorganic solid particles (melt modification process), in which a powdery additive which contains the inorganic solid particles with a maximum particle size of 1 &mgr;m embedded in finely divided form in a matrix of an organic substance, the organic substance containing one or more of the substances from the group consisting of polyols, polyglycols, polyethers, dicarboxylic acids and derivatives thereof, AH salt, caprolactam, paraffins, phosphoric acid esters, hydroxycarboxylic acid esters and cellulose, is incorporated into the polymer.

Abstract: A delustering composition for acetyl cellulose fibers is described which contains 15 to 85% by weight TiO.sub.2, 15 to 85% by weight paraffin oil and 0.5 to 10% by weight dispersing agent. Furthermore, a method for producing the delustering composition and also the use thereof for delustering acetyl cellulose fibers is described. Finally, the use of the delustered acetyl cellulose fibers in the production of cigarette filters and textile products is described.