PURPOSE: To prepare a dispersion capable of forming a high-gloss coating film on the surface of paper without pollution of working environment, and suitable for manufacturing high-gloss metallized paper, by dispersing a specific ethylene/ α,β-unsaturated carboxylic acid copolymer resin having a specific range of melt index, in water.

CONSTITUTION: An ethylene/acrylic (or methacrylic) acid copolymer having a melt index of 5W400g/10min (pref. 10W300g/10min) at 125°C is prepared from (A) 95W55(wt)%, pref. 90W70% ethylene and (B) 5W45%, pref. 10W30% α,β- unsaturated carboxylic acid (e.g. acrylic acid) wherein ≥10mol% of the acid group is neutralized with a base (e.g. alkali metal). The objective dispersion is obtained by dissolving or dispersing the copolymer in hot water if necessary in the presence of a small amount of anionic surface-active agent or nonionic surface-active agent. Metallized paper can be manufactured by depositing metal in vacuum on the coating film obtained by coating a paper sheet with the dispersion or solution.