Application of a non-fluoro hydrophobic aqueous-based polyurethane resin dispersion

Abstract

The present invention provides a cross-linking non-fluoro hydrophobic aqueous polyurethane dispersion, which is produced by selecting a compound comprising alcohols, amines, acids, saturated or unsaturated (double-bonded or epoxidized) aliphatic long chain carbon-carbon groups or polydimethylsiloxane comprising alcohol groups, amines, oxosilane to be reacted with IPDI to obtain a PU prepolymer; adding a compound having tertiary amines to neutralize the carboxylic acid of PU prepolymer and adding water to disperse the PU prepolymer; and adding a ambient temperature cross-linking agent to obtain a cross-linking hydrophobic aqueous PU dispersion of the present invention. The hydrophobic aqueous-based PU resin has no fluorine which is friendly to the environment, and may further self cross-links on its applications on fabric, paper, wood, glass and metal surfaces, respectively on drying at ambient temperature which is energy saving process. Its cross-linking reaction of this hydrophobic PU system that will achieve a long-lasting water repellent surface treatment.

1 . An use of water repellent applied an aqueous polyurethane dispersion, wherein the polyurethane dispersion obtained by the production method comprises the following steps:
 selecting a compound comprising alcohols, amines, carboxylic acids, saturated or double-bonded or epoxidized aliphatic groups or polydimethylsiloxane comprising alcohol groups, amino groups, oxosilane to be reacted with polyisocyante to obtain a polyurethane prepolymer having isocynate (NCO) terminal group;   adding a compound having hydrophilic functional groups into the polyurethane prepolymer having isocyanate terminal groups, after neutralizing, adding water to disperse the polyurethane prepolymer to form an aqueous polyurethane dispersion; and   adding a room-temperature cross-linking agent into the aqueous polyurethane dispersion to obtain a self-crosslinked aqueous polyurethane dispersion.   
     
     
         2 . The use according to  claim 1 , wherein the polyurethane dispersion is applied on an object which is going to be coated under pH value less than 7 to make the carboxylate reactive functional groups comprised react with a cross-linking agent to generate an open ring cross-linking reaction. 
     
     
         3 . The use according to  claim 2 , wherein the object which is going to be coated has hydroxyl groups, carboxylic acids, epoxy groups or amino groups. 
     
     
         4 . The use according to  claim 3 , wherein the silane groups comprised in the polyurethane dispersion reacts with hydroxyl groups or amino groups of the object which is going to be coated to form chemical bonding. 
     
     
         5 . The use according to  claim 4 , wherein the polyurethane dispersion can be coated on a surface of the object which is going to be coated by a method of scraper, roller, impregnation, spray or screen printing and the like.