PROCESS FOR PREPARING AQUEOUS DISPERSIONS OF HYBRID POLYURETHANE PARTICLES

• Main Authors: BEDRI, ERDEM, DEBKUMAR, BHATTACHARJEE, SCHROCK, ALAN, K
• Format: Patent
• Language: English; French
• Published: 18.07.2002
• Edition: 7
• Subjects: ADHESIVES; CHEMICAL PAINT OR INK REMOVERS; CHEMISTRY; COATING COMPOSITIONS, e.g. PAINTS, VARNISHES ORLACQUERS; COMPOSITIONS BASED THEREON; CORRECTING FLUIDS; DYES; FILLING PASTES; INKS; MACROMOLECULAR COMPOUNDS OBTAINED BY REACTIONS ONLY INVOLVINGCARBON-TO-CARBON UNSATURATED BONDS; MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONSONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS; METALLURGY; MISCELLANEOUS APPLICATIONS OF MATERIALS; MISCELLANEOUS COMPOSITIONS; NATURAL RESINS; ORGANIC MACROMOLECULAR COMPOUNDS; PAINTS; PASTES OR SOLIDS FOR COLOURING OR PRINTING; POLISHES; THEIR PREPARATION OR CHEMICAL WORKING-UP; USE OF MATERIALS THEREFOR; WOODSTAINS

Dispersions of hybrid polyurethane particles are made using miniemulsion techniques. An isocyanate-terminated prepolymer and a monomer are mixed and dispersed in an aqueous phase to form a dispersion of droplets. All droplets are polymerized and chain-extended in one step to form hybrid particles containing a polyurethane and a polymer of the monomer. This process provides a simple method of making hybrid particles, in which particle size and the number of particles is controlled in the mixing step. The hybrid particles often have a coreshell morphology, with the polyurethan being concentrated in the shell and the polymer being concentrated in the center of the particle. L'invention concerne des dispersions de particules hybrides de polyuréthanne préparées à l'aide de techniques de mini-émulsion. On mélange et on disperse un prépolymère à terminaison isocyanate et un monomère dans une phase aqueuse afin de former une dispersion de gouttelettes. Toutes les gouttelettes sont polymérisées et subissent une extension de chaîne dans une même étape afin de former des particules hybrides contenant un polyuréthanne et un polymère de monomère. Ce procédé constitue une méthode simple de production de particules hybrides, la granulométrie et le nombre de ces particules étant régulés dans l'étape de mélange. Lesdites particules hybrides possèdent souvent une morphologie du type coque, le polyuréthanne étant concentré dans ladite coque et le polymère étant concentré dans le centre de la particule.