The invention relates to a waterborne
polyurethane resin for a
toluene reduced ultrafine
fiber base and a preparation method and application of the waterborne
polyurethane resin. The waterborne
polyurethane resin is prepared by the following methods: performing a stirring reaction on
polyester polyol, polyether
polyol and diisocyanate at a temperature of 65-95 DEG C for 1-3 hours, successively adding a glycol type chain extension agent and a
carboxylic acid type hydrophilic chain
extender, and performing a chain extension reaction respectively so as to obtain a
prepolymer; and cooling the
prepolymer to a temperature less than or equal to 60 DEG C, adding a low
boiling point solvent, performing uniform stirring, adding a neutralizing
reagent, performing stirring for 0.5-2 hours, performingcooling to a temperature less than or equal to 40 DEG C, adding water, performing
emulsion, after
emulsion is completed, firstly adding a hydrophilic chain
extender and a
diamine type chain
extender,performing chain extension respectively, after the operation, increasing the temperature greater than or equal to 70 DEG C, performing vacuum
desorption of the
solvent, and performing cooling and
discharge, so as to obtain the waterborne polyurethane resin. The resin is used in preparation of the
toluene reduced ultrafine
fiber base, and the obtained base is high in bass thickness
retention rate,soft and plump in hand feel, good in elasticity, high in tensile strength and good in
tear resistance.