PROCESS FOR THE PRODUCTION OF NOVEL RADIATION CURABLE MICROCAPSULAR COATING COMPOSITIONS

摘要

This invention relates to a process for producing a radiation curable coating composition containing microcapsules having a hydrophobic liquid core comprising the following steps: An emulsion containing droplets of a hydrophobic emulsion component dispersed in a hydrophilic emulsion component is prepared. The hydrophobic emulsion component comprises a hydrophobic liquid. The hydrophobic emulsion component additionally contains a first wallforming material capable of reacting by condensation polymerization with a second wall-forming material to form a polymeric capsule wall. The first wallforming material is soluble in the hydrophobic emulsion component. The polymeric capsule wall is substantially insoluble in the hydrophilic and the hydrophobic emulsion components. The hydrophilic emulsion component comprises an emulsifier dispersed in a radiation curable hydrophilic liquid. The radiation curable hydrophilic liquid comprises water and at least one radiation curable polar compound. The emulsion additionally contains the second wall-forming material. The emulsion is subjected, with stirring, to temperature conditions for a period of time sufficient to react the first and second wall-forming materials to form a dispersion of microcapsules in the hydrophilic emulsion component. The microcapsules have capsule walls substantially impermeable to the hydrophilic and the hydrophobic emulsion components. The radiation curable dispersion so produced can be coated on a paper substrate and set by subjecting the dispersion on the paper substrate to radiation for a period of time sufficient to polymerize the radiation curable hydrophilic liquid to a tack-free resinous film on the paper substrate. The radiation is a combination of ultraviolet and infra-red radiation. The invention further relates to a radiation curable coating composition containing microcapsules. The microcapsules have a hydrophobic liquid core and are dispersed in a radiation curable hydrophilic liquid. The radiation curable hydrophilic liquid comprises a polar radiation curable compound and water. The radiation curable coating composition additionally contains a photoinitiator.