MANUFACTURING PROCESS OF NO-SOLVENT TYPE WATER-DISPERSIVE POLYURETHANE RESIN FOR DIP COATING OF SUEDES

摘要

The present invention relates to a method for producing a solvent-free water-dispersible polyurethane resin for suede impregnating coating, a polycarbonate polyol having a weight average molecular weight of 1,000 to 3,000 (a) 10 to 15% by weight, and a polyether polyol having a weight average molecular weight of 1,000 to 3,000. (b) 2 to 5% by weight, chain extender (c) 0.5 to 0.8% by weight, and dispersant (d) 1.0 to 1.6% by weight for the improvement of flowability and viscosity was added and melt-stirred at a temperature of 50° C., A first step of adding 5 to 14% by weight of diisocyanate (e) and raising the temperature to 90° C., then adding a bismuth carboxylate catalyst and raising the temperature to 120° C.; After adding 1 to 2% by weight of triol (f) for adjustment of strength and post-curing properties, further reacted, cooled to 60°C, and then reacted with 0.4 to 0.8% by weight of blocking agent (g) to prepare the prepolymer. A second step of manufacturing; The polyether polyol (h) with a weight average molecular weight of 2,000 to 3,000 (h) 6.8 to 13.5 wt%, isocyanate (i) 1.1 to 2.2 wt%, and a hydrophilic polyether polyol with a weight average molecular weight of 1,000 to 2,000 (j) 2.3 to 4.6 wt% are 120 After dispersing the emulsifying aid prepared by reacting for 2 hours at ℃ and the neutralizing agent having the same molar ratio as the dispersant (d) in 40 to 60% by weight of water at 20 to 30°C, the prepolymer prepared in the second step is mixed And kneading at high speed to prepare a prepolymer dispersion; 5 to 8% by weight of polyether amine (k) having a weight average molecular weight of 1,000 to 3,000 for adjustment of chain extension and flexibility, and 0.05 to 0.3% by weight of low molecular amine (l) in the prepolymer dispersion prepared in the third step It is characterized by consisting of a fourth step. The solvent-free water-dispersible polyurethane resin for suede impregnating coating obtained by the production method of the present invention has excellent mechanical strength and durability by applying polycarbonate polyol, and is applied to an emulsifying aid and polyether amine even at a high solid content of at least 45% 2,000. Since it has the advantage of being able to form excellent coating film properties without a curing agent through the application of a blocking agent and a triol that has a low viscosity of cP/25°C or lower and also dissociates at high temperature, the suede material to which it is applied forms a sufficient coating film while coating It has an excellent feel and excellent durability.