Process for coating dispersed minute droplets with membrane
AssigneeMitsubishi Paper Mills Limited
InventorsTetsuro Shimazaki, Shun Kamei
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Abstract
Microcapsules containing water-insoluble liquid, of which wall membrane is urea-formaldehyde resin is produced by the addition of a water soluble organic acid, urea and formaldehyde to an emulsion of the liquid, which is made by a nonionic emulsifier and heating the emulsion to effect the polycondensation of urea and formaldehyde.
Claims7
A process for coating dispersed minute droplets with membrane by polycondensation, which comprises mixing together a solvent containing a nonionic emulsifier and a solvent substantially insoluble in the former solvent, thereby forming a dispersion of minute droplets, the dispersion medium of the dispersion being a water-containing solvent and the nonionic emulsifier being present in an amount of 15% by weight or less based on the dispersion;
- adding one or more organic acids soluble in said dispersion;
- adding urea and formaldehyde to said dispersion;
- adding an aromatic polyol to said dispersion;
- and effecting polycondensation to form membrane around the dispersed droplets in said dispersion.
Dependencies are inferred from the claim text.