Method of preparing water-based surface treatment agent and water-based surface treatment agent prepared using the same

A method of preparing a water-based surface treatment agent, comprising:

• (a) adding 1 to 25 parts by weight of a curing agent (B) to 1 to 25 parts by weight of a water-based solvent (C) and performing stirring at 20 to 30° C. for 40 minutes to 5 hours;
• (b) adding 1 to 10 parts by weight of a silicon compound (D), 0.1 to 0.5 parts by weight of an antifoaming agent and 0.1 to 0.5 parts by weight of a leveling agent to 100 parts by weight of a main material (A), and performing stirring at 20 to 30° C.;
• and
• (c) adding the mixture of step (a) to the mixture of step (b) and performing stirring at 20 to 30° C. for 0.2 to 1 hour, and
• wherein the water-based solvent (C) comprises water, an alcohol, or a mixture thereof,
• wherein the main material (A) is a main material (A-1), wherein the main material (A-1) comprises a polyurethane having one or more functional groups selected from the group consisting of a carboxylic acid group, a hydroxyl group, an amino group, and a combination thereof per molecule, dispersed in an amount of 5 to 30% by weight in a water-based solvent, and
• wherein the silicon compound (D) is a polysiloxane of a liquid form dispersed in water or a polysiloxane of a bead form, wherein a content of the polysiloxane in the silicon compound of a liquid form is 5 to 30% by weight.