QUICK-DRYING SOLVENT-FREE SAG-RESISTANT POLYURETHANE WATERPROOF COATING AND PREPARATION METHOD THEREFOR

摘要

A quick-drying solvent-free sag-resistant polyurethane waterproof coating and preparation method therefor, raw materials therefor comprising a polyurethane prepolymer, a plasticizer, a dispersant, a filler, a dehydrant, a catalyst, a defoamant, and an oxazolidine reactive diluent. The catalyst is composed of pentamethyl dipropylene triamine, tetramethylethylenediamine, and 1,8-diazabicyclo[5.4.0]undecene. Raw materials of the polyurethane prepolymer comprise a polyether diol, a polyether triol, an isocyanate, and a chain extender. The prepolymer is prepared by means of the following method: 1) measuring out the raw materials for the polyurethane prepolymer, and reacting the polyether diol with the isocyanate until reaction is complete; 2) then adding the polyether triol for reaction until reaction is complete; 3) then adding the chain extender for reaction, completing preparation. The waterproof coating preparation method is: i) preparing the polyurethane prepolymer; ii) mixing the prepared polyurethane prepolymer with the rest of the raw materials for the waterproof coating to obtain the final product. The present waterproof coating features such advantages as exceptional film-forming speed and sag resistance, and low viscosity.