Polyurethane-based adhesive composition, surface protection film comprising same, method for manufacturing surface protection film, and method for manufacturing organic light-emitting electronic device

A surface protective film comprising:

• a base film;
• and
• an adhesive film comprising polyurethane-based adhesive composition, or a cured material thereof, provided on one surface of the base film,
• wherein the polyurethane-based adhesive composition comprising:
• a polyurethane polymer comprising a difunctional polyol and a trifunctional polyol;
• and
• an isocyanate-based crosslinking agent,
• wherein the adhesive composition has viscosity of greater than or equal to 1,000 cPs and less than or equal to 10,000 cPs under a condition of 25° C. and relative humidity of 60%;
• the difunctional polyol is included in an amount of 5 parts by weight to 40 parts by weight, based on 100 parts by weight of the polyurethane polymer;
• and
• the trifunctional polyol is included in an amount of 60 parts by weight to 95 parts by weight, based on 100 parts by weight of the polyurethane polymer and,
• wherein the base film has a thickness of greater than or equal to 25 μm and less than or equal to 150 μm,
• wherein the adhesive film has a thickness of greater than or equal to 10 μm and less than or equal to 100 μm,
• wherein low-rate peel strength is 5 gf/inch or greater when bonding one surface of the adhesive film to a glass substrate and then peeling at a peeling angle of 1800 and a rate of 1.8 m/min, and high-rate peel strength is 50 gf/inch or less when bonding one surface of the adhesive film to a glass substrate and peeling at a peeling angle of 180° and a rate of 20 m/min;
• and
• wherein a hydroxyl group of the polyurethane polymer and an isocyanate functional group have a molar ratio (—OH/NCO) of greater than or equal to 1.3 and less than or equal to 1.7.