| 摘要 |
The invention relates to improved carboxylated styrenic polymers suited for use in the graphic arts industries as dispersants for pigments and varnishes. The base polymer comprises polymerized units of styrene and an alpha , beta -unsaturated monocarboxylic acid, with said polymer incorporating hydrophilic functionality. The improvement in the polymer composition comprises the polymerized incorporation of hydrophilic functionality based upon the half acid ester of an alpha , beta -unsaturated dicarboxylic acid or anhydride thereof and a polyethylene glycol monoether having greater than three ethylene oxide units. The half ester not only provides surfactant properties to the polymer through the incorporation of the polyethylene glycol ether but also provides carboxyl functionality necessary for water dispersibility. The number average molecular weight is from 1,500 to 20,000 and the acid numbers for these polymers typically range from 125 to 300.
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