| 摘要 |
1. A finely divided polymer dispersion which contains polymerized units of nitrogen-containing monomers, and is obtained by a two-stage polymerization reaction, wherein, in the first polymerization stage, a low molecular weight prepolymer, which has a viscosity of from 1.06 to 1.40 (measured in an Ubbelohde viscometer) in a 1% strength solution of a mixture of 99 parts by weight of dimethyl formamide and 1 part by weight of glacial acetic acid at 20 degrees C, is prepared in a water-miscible solvent, which may contain up to 15% by weight of water, in the manner of a solution copolymerization from a monomer mixture which contains (a) per mole of a nitrogen-containing monomer of the formula see diagramm : EP0051144,P13,F1 or see diagramm : EP0051144,P13,F3 where A is O or NH, B is Cn H2n , n being from 1 to 8, R**1 and R**2 are each Cm H2m+1 , m being from 1 to 4, R**3 is H or CH3 , X4 **- is OH**- , Cl**- , Br**- or CH3 -OSO3 H**- , and R**4 is Cm H2m+1 , m being from 1 to 4, (b) 2.5 to 10 moles of at least one nonionic, hydrophobic, ethylenically unsaturated monomer which, if it is polymerized on its own, forms a hydrophobic polymer, (c) 0.5 to 1.5 moles of an ethylenically unsaturated carboxylic acid or maleic anhydride, and (d) 0 to 7 moles of a nonionic, hydrophilic, ethylenically unsaturated monomer, the solution of the prepolymer is diluted with water in a weight ratio of from 1:3 to 1:50 and, in the second polymerization stage, 1 to 32 parts by weight of at least one nonionic, hydrophobic, ethylenically unsaturated monomer, which is the same as monomer (b) of the prepolymer, are polymerized per part by weight of the solution polymer in this polymer solution in the manner of an emulsion polymerization in the presence of a usual amount of a water-soluble polymerization initiator. |
