A coating resin that is thermoplastic, exhibits good appearance, solvent resistance and adherence and is excellent in abrasion resistance; and a coting liquid or coating film thereof. In particular, a (meth)acrylic copolymer resin (A) produced by radical polymerization of 4 to 50 mass % of (meth)acrylic acid (a-1), 0.5 to 17 mass % of (meth)acrylamide (a-2), and 35 to 95.5 mass % of a compound having reactive unsaturated bond other than the compounds (a-1) and (a-2). With respect to the coating film produced therefrom, both the glass transition temperature Tg1 measured by means of a rigid-body pendulum type viscoelasticity measuring instrument and the glass transition temperature Tg2 measured by means of a differential scanning calorimeter (DSC) are 110.degree. C. or higher. The coating film is an abrasion resistant film whose abrasion resistance measured in accordance with the Taber abrasion testing method is 80 rotations or greater.