Water-based polyurethane resin and manufacturing method thereof

A method for manufacturing a water-based polyurethane resin, comprising:

• (1) a preparation step of a prepolymer:
• vacuum-dehydrating 105.24 g of a polyol and adding the vacuum-dehydrated polyol into a reactor, and adding 51.3 g of a polyisocyanate into the reactor when an oil bath temperature reaches 70° C. to 80° C. to carry out a synthetic reaction so as to obtain the prepolymer, wherein the polyol includes 20 g of polyester polyol synthesized from tricyclodecane dimethanol and adipic acid;
• (2) a dilution step of the prepolymer:
• adding 179 g of an acrylic monomer to reduce the viscosity of the prepolymer and maintaining a reaction temperature at 85° C. to 90° C. for 2 to 3 hours, and subsequently adding 26.4 g of sulfonate hydrophilic agent to continue the reaction for 25 to 40 minutes so as to obtain a polymer;
• (3) a water dispersion and chain extension step:
• cooling the polymer obtained from the step (2) to room temperature and adding 472.6 g of deionized water to the polymer under a high-speed shearing force that is generated at a rotational speed of 500 rpm, and subsequently adding 1.9 g of a chain extender to carry out a chain extension reaction for 30 minutes so as to obtain a water-based polyurethane dispersion;
• and
• (4) an acrylic synthesis step:
• mixing the water-based polyurethane dispersion obtained from the step (3) with 43.8 g of an emulsifier to form an emulsion, raising the reaction temperature to 50° C. to 70° C. after stirring evenly and then dropwise adding 0.4 g of an initiator, carrying out an acrylic polymerization reaction at 75° C. to 85° C. for 1 to 3 hours, and adding 0.15 g of a reducing agent after reducing the reaction temperature to 50° C. to 70° C. so as to obtain the water-based polyurethane resin;
• wherein all of the polyol, the polyisocyanate and the acrylic monomer include a cyclic structure compound.