The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jul. 17, 1984
Filed:
Feb. 23, 1982
Yuriko Igarashi, Iwaki, JP;
Yoshio Okada, Iwaki, JP;
Kureha Kagaku Kogyo Kabushiki Kaisha, Nihonbashi, JP;
Abstract
Disclosed herein a process for producing a microcapsule having an excellent solvent-resistance and a thermal stability, and an extremely minute amount of unreacted formaldehyde, comprising the steps of dispersing a substance to be encapsulated into an aqueous solution containing a water-soluble cationic urea resin, at least one prepolymer selected from the group consisting of a melamine-formaldehyde prepolymer, a urea-formaldehyde prepolymer and a melamine-urea-formaldehyde prepolymer and an anionic surfactant and then, adding an acid-catalyst into the thus obtained aqueous dispersion thereby forming a wall membrane which encapsulates the dispersed microparticle of the substance to be encapsulated by polycondensing the prepolymer and the cationic urea resin followed by cross-linking while causing complex coacervation, and adding a monosaccharide into the aqueous dispersion while adjusting the pH of the aqueous dispersion with the addition of a hydroxide of an alkaline earth metal thereby removing the unreacted residual formaldehyde remaining in the aqueous dispersion.