Viscosity modifier, and emulsion resin composition or aqueous coating composition each containing same

A viscosity modifier, which is produced by a preparation method comprising the steps of:

• obtaining secondary alcohol ethoxylates by adding ethylene oxide to alcohols represented by the following formulae (4) and (5);
• and then
• reacting said alcohol ethoxylates and a compound represented by the following formula (6) with diisocyanates represented by the following formulae (7) and (8):
• HOC2H4OxH (6)
• OCN—R5—NCO (7)
• OCN—R6—NCO (8)
• where:
• R1 to R4 each represent a linear alkyl group having 1 to 13 carbon atoms;
• R5 and R6 each represent a group represented by the following formula (2) or (3);
• and x represents a number from 40 to 800, provided that each of a total number of carbon atoms in R1 and R2 and a total number of carbon atoms in R3 and R4 is from 11 to 13: