A process for producing a resin is disclosed, comprising reacting (a) a polyalkylenepolyamine, (b) an alicyclic dibasic carboxylic acid and/or a reaction product having a free carboxyl group that is obtained by reacting an alicyclic dibasic carboxylic acid with a glycol, (c) a urea, and (d) an aldehyde and/or an alkylating agent. The resulting resin is useful as a wet strength agent to provide a paper coating composition having improved printability and printing effects.