| 摘要 |
A polymer dispersant for pigments based on a graft copolymer which contains a new type of urea functional group as the pigment anchoring group. The urea groups are attached to the graft copolymer by a convenient method which involves reaction of hydroxyl functional groups built in the graft copolymer with a diisocyanate that is capped at one end with ammonia or a primary or secondary amine. The reaction is convenient and clean. Substantial crosslinking or gelling of the polymer can be easily avoided by judicious selection of appropriate ingredients and processing conditions. These materials are effective in dispersing and stabilizing a wide range of pigments in solvent based systems and are particularly useful in forming pigment dispersions that are used in a variety of solvent borne coating compositions for automobiles and trucks, where they provide improved efficiency of pigment use, lower paint viscosity, and reduced emission of volatile organic solvent.
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