AQUEOUS DISPERSIONS OF POLYMERS WHICH COMPRISE A FLUORESCENT DYE, PROCESS FOR THEIR PRODUCTION AND THEIR USE FOR MARKING MATERIALS

摘要

Aqueous dispersions of polymers which are obtainable by free-radical suspension polymerization of ethylenically unsaturated monomers in an oil-in-water emulsion whose disperse phase comprises at least one fluorescent dye dissolved in at least one ethylenically unsaturated monomer and has a mean particle diameter of at least 1 µm, in the presence of at least one surface-active compound and at least 0.5% by weight, based on the monomers, of at least one hydrophobic nonpolymerizable organic compound, of a hydrophobic polymer formed from at least one C2- to C8-olefin having a molar mass Mw up to 10 000, of a siloxane having a molar mass Mw up to 5000 and/or polystyrene having a molar mass Mw up to 10 000, processes for preparing said dispersions and use of aqueous dispersions of polymers which are obtainable by free-radical suspension polymerization or by free-radical miniemulsion polymerization of ethylenically unsaturated monomers in an oil-in-water emulsion whose disperse phase comprises at least one fluorescent dye dissolved in at least one ethylenically unsaturated monomer and has a mean particle diameter of at least 100 nm, in the presence of at least one surface-active compound and at least 0.5% by weight, based on the monomers, of at least one hydrophobic nonpolymerizable organic compound, of a hydrophobic polymer formed from at least one C2- to C8-olefin having a molar mass Mw up to 10 000, of a siloxane having a molar mass Mw up to 5000 and/or of polystyrene having a molar mass Mw up to 10 000, and the powder which comprises at least one fluorescent dye and is obtainable from these polymer dispersions by drying in each case for marking materials.