Polymer prepared from octadienol and unsaturated dicarboxylic acid,

Abstract

The present invention provides a relatively low molecular weight polymer comprising units derived from an unsaturated dicarboxylic acid and units derived from octadienol. The polymer exhibits a fluid viscosity of at least about 200 cp when measured in the neat state at room temperature using a Brookfield viscosimeter. The unsaturated dicarboxylic acids from which the polymer units are derived include fumaric acid, maleic acid, and mixtures thereof. The octadienol from which the polymer units are derived commonly comprises a mixture of 2,7-octadien-1-ol and 1,7-octadien-3-ol. Preferably, the polymer exhibits a fluid viscosity of about 700-900 cp. The process for preparing the polymer comprises reacting octadienol with an unsaturated dicarboxylic acid selected from fumaric acid, maleic acid, lower alkyl diesters of said acid, and mixtures thereof in the presence of an esterification catalyst. Preferably, the esterification catalyst comprises dibutyltin oxide and is present in an amount of about 0.01 to 1% by weight. The coating composition provided by the present invention comprises the relatively low molecular weight polymer together with a promoter system comprising organic salts of cobalt and manganese. The promoter system is present in the composition in a concentration such that the weight of metal in the promoter system is about 0.01 to 0.5% of the weight of polymer. The coating composition may further comprise one or more additives selected from pigments, anti-skinning agents, flow control agents, solvents, propellants, additional polymeric resins, and other additives well known in the art.