A METHOD FOR PREVENTING HARDENER COMPOUNDS TO BE FORMED FROM HARDENER PRECURSORS AND EXTENDING SHELF LIFE OF THE DISPERSION

摘要

The invention relates to paint forming, pressurized dispersion in a sealed aerosol can said dispersion having an extended shelf life, comprising an epoxy resin, epoxy hardener precursors, ketones, organic solvent, pigments, paint additives, dispersion additives, propellant and 1-10000 ppm of free water into said sealed can which has been provided alongside with said paint forming chemicals into said can. Epoxy hardener precursors are selected from the group consisting of an imine, an enamine, a Mannich base, a Schiff's base, aldimine, an azole preferable an oxazole such as an oxazolidine and mixtures thereof; - for extending the shelf life of the dispersion, the amount of weak acid (XCOOH) is adapted on the basis of H 2 O (free water) present in the can, for preventing the formation of epoxy hardeners from said epoxy hardener precursors, wherein said epoxy hardener is a compound with amine functionality, the amount of the weak acid being adapted in the range of 0.01-10% by weight (w/w) of the paint forming dispersion, preferably from 0.1 to 5%, still more preferably from 0.25 to 2 %, which weak acid is further selected from the group which have the p K a value in the range from 1.2 to 9.9 preferably 1.2-5.2; - additionally also temporary hydrolyzed products of said epoxy hardener precursors are present in said dispersion, which hydrolyzed products are carbino-lamines, which originate to the reversible reaction (2a; 2a1) catalyzed by said weak acid (XCOOH) - the amount of epoxy hardeners, free water, ketones, propellant and possible organic solvent, possible pigments is at least 95% w/w from the total volume of the paint forming solution and the rest of said solution composes of the paint additives and dispersion additives.