| 摘要 |
The invention relates to aqueous polymer dispersions, obtained by the radically initiated copolymerisation of (a) between 0.1 and 99.9 wt. % styre ne and/or methylstyrene, (b) between 0.1 and 99.9 wt. % 1,3-butadiene and/or isoprene and (c) between 0 and 40 wt. % of other ethylenically unsaturated copolymerisable monomers, whereby the sum of the monomers (a), (b) and (c) always equals 100, in the presence of between 10 and 40 wt. %, in relation t o the monomers used, of at least one degraded starch with a molecular weight ranging between 500 and 40,000 Mn and water soluble redox catalysts. The invention also relates to a method for producing the polymer dispersions by the radical polymerisation of the monomers (a), (b) and optionally (c) in an aqueous medium in the presence of a degraded starch with a molecular weight ranging between 500 and 10,000 Mn and redox initiators and to the use of the aqueous polymer dispersions obtained by said method as pulp sizing and surfa ce sizing agents for paper.
|
