| 摘要 |
1. One part polyurethane binder containing polystyrol, blocked urethane prepolymer, possibly catalysts and fillers, flexibilisers, fluidity enhancing agents and other additives, characterised in that it contains 40 to 60 parts by weight of polystyrol with hydroxyl value of 40-90 mg KOH/g, acid value of less than 2 mg KOH/g and viscosity of 200-900 mPa.s at the temperature of 70 degrees C, and from 60 to 40 parts by weight of blocked urethane prepolymer obtained from the same polystyrol, diisocyanates and blocking compounds, preferably at the ratio of 1 mole of polystyrol hydroxyl groups to 0.9-1.3, preferably 1.0-1.1 mole of blocked isocyanate groups.3. Method for producing one part polyurethane binder by heating polystyrol with the excess of diisocyanate and then isocyanate groups blocking agent, resulting in creating urethane prepolymer, which is heated with polystyrol and possibly catalysts, flexibilisers, fluidity enhancing agents and other additives, characterised in that the same polystyrol is used for the production of blocked urethane prepolymer and for heating with that prepolymer, with hydroxyl value of 40-90 mg KOH/g and acid value below 2 mg KOH/g, consisting of the radicals of adipic, sebacic, succinic, isophthalic and/or terephthalic acids, or their mixtures and radicals of ethylene glycol, diethylene glycol, propylene glycol, dipropylene glycol, butylene glycol, pentanodiol, hexanediol, neopentyl glycol, as well as trimethylolpropane and glycerine, and 70-130 parts by weight of polystyrol per 100 parts by weight of blocked urethane prepolymer are used, while polystyrol is heated with diisocyanate at the temperature of 70-120 degrees C, with a blocking agent at the temperature of 80-110 degrees C, and blocked urethane prepolymer is heated with polystyrol at the temperature of 60-80 degrees C.
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