| 摘要 |
Described is a process for preparing an aqueous pressure-sensitive adhesive dispersion from ethylenically unsaturated, free-radically polymerizable monomers. In a first stage, a first polymer is prepared by free-radical emulsion polymerization. In a second stage, an aqueous polymer dispersion is prepared in the presence of the first polymer, where the glass transition temperature calculated for a polymer prepared from the monomers of the second stage is less than −20° C. The monomers of the first stage comprise monomers with acid groups. The polymerization of the first stage takes place at a low pH of less than 5. The acid groups of the first polymer are neutralized during, or before and during, the polymerization of the second stage to an extent such that the pH of the polymer dispersion at the end of the second stage is greater than 5. The aqueous pressure-sensitive adhesive dispersions can be used for producing self-adhesive articles, especially self-adhesive labels and adhesive tapes. |
