| 主权项 |
1. An electrocoating composition comprising a film-forming binder and an anticrater additive in an amount of from 0.1 to 20 wt. % of the film forming binder, the anticrater additive comprising a copolymer that is the reaction product of an isocyanate containing compound with an isocyanate blocking compound, wherein the isocyanate containing compound has a structure according to the formula:
(OCN)n-X—N(H)—C(O)-G-R—S—Z; wherein n is an integer from 1 to 6; X is selected from the group consisting of aryl, alkyl, cycloalkyl groups and a combination thereof having up to 60 carbon atoms; wherein each of the aryl, alkyl, cycloalkyl groups can optionally be substituted with an isocyanurate group, an iminooxadiazine dione group, an allophanate group, a biuret group, a urea group, a urethane group or a uretidione group; G is selected from the group consisting of N(R1) and a direct bond; R is selected from the group consisting of aryl, alkyl, cycloalkyl groups and a combination thereof having up to 20 carbon atoms, and R can optionally contain amide, ester, ether, urethane and/or urea groups; R1 is selected from the group consisting of H, aryl, alkyl, cycloalkyl groups and a combination thereof having up to 20 carbon atoms; and Z comprises polymerized (meth)acrylic monomers, wherein the polymerized (meth)acrylic monomers have a weight average molecular weight of from about 1,000 to about 10,000, wherein the isocyanate blocking compound is one or more selected from the group consisting of methanol, ethanol, propanol, isopropanol, butanol, isobutanol, trimethylolpropane, ethylene glycol monoalkyl ethers, and diethylene glycol monobutyl ether. |
