Formaldehyde-free durable easy-care resin and preparation method and application thereof

The invention discloses a formaldehyde-free durable easy-care resin and a preparation method and application thereof, belonging to the technical field of cotton fabric after-finishing agents in the dyeing and finishing industry. The preparation method is characterized by comprising the following steps of: performing a reaction for 1-5 hours between urea and a glyoxal solution under the conditions that the pH value is 4-8 and the temperature is 30-80 DEG C to obtain an intermediate product dihydroxy ethylene urea; performing a reaction for 1-6 hours between the dihydroxy ethylene urea and dialdehyde under the conditions that the molar ratio is 1:2-2:1, the pH value is 4-8 and the temperature is 30-60 DEG C to obtain an unetherified formaldehyde-free durable easy-care resin; adjusting the pH value of the resin to 2-4; adding an alcohol compound and reacting at the temperature of 30-80 DEG C for 0.5-4 hours; and then reducing the temperature and adjusting the pH value to 6-7 to obtain the formaldehyde-free durable easy-care resin. The resin disclosed by the invention is applied to the easy-care finishing of cotton fabrics, and has the advantages of good easy-care effect and little strength loss; and in a using process, the resin does not release formaldehyde so as to meet the requirement of ecological environmental protection.