| 摘要 |
Production of aqueous cationic dispersions of hydrophobic polymers, based on emulsion polymerization at 30-100 deg C of at least one emulsion polymerizable polymer, stabilized with 20-60 wt.% (in relation to the monomers) of styrene-maleic anhydride imide copolymers with low molecular weight, acting as surfactant. The dispersion has a dry substances content of 20-50 %. Independent claims are also included for: 1) cationic dispersion of polymers of hydrophobic character, with particle size preferably 50-500 nm, most preferably up to 300 nm, obtained in process as claimed; 2) the use of the dispersion as claimed as internal a sizing agent for paper and cardboard, or in combination with other sizing agents such as starch, for the surface sizing of paper and cardboard; and 3) the composition for external sizing of paper and cardboard, containing the dispersion as claimed and starch (5-50 wt.%).
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