Repulpable hot melt polymer/fatty acid compositions for fibrous products

Abstract

Hot melt polymer/fatty acid compositions are described that render fibrous products such as paper, paperboard and corrugated paper containers water-resistant at room temperature, but enable such articles to be repulped and recycled when the coated articles are repulped in a heated nearly neutral to alkaline pH aqueous medium. The compositions comprise from about 5% to 50% by weight of an addition polymer of from about 5 to 95 mole percent of an ethylenically unsaturated monocarboxylic acid or 50 to 95 mole percent of an ethylene-1,2-dicarboxylic acid or anhydride and the balance to a total of 100 mole percent of at least one additional ethylenically unsaturated monomer selected from the group consisting of 1-alkenes having from about 4 to 60 carbon atoms; alkyl vinyl ethers having an ether alkyl group of from about 8 to 60 carbon atoms, and alkyl acrylates or alkyl methacrylates having an alkyl group of from about 8 to 60 carbon atoms; optionally from about 1 to 90 mole percent of the carboxyl groups in the polymer may be further modified by reaction with a substituted or unsubstituted monoalcohol or monoamine; and from about 50% to 95% by weight of at least one fatty acid selected from the group consisting of natural or synthetic fatty acids containing from about 12 to 48 carbon atoms, wherein the fatty acid is compatible with the polymer and the composition is a solid at 20.degree. C., but starts to become fluid between about 50.degree. C. to 95.degree. C.