Method for producing glass unit and pressure-sensitive adhesive sheet

A method for protecting an article surface, the method comprising:

• a step of applying a protective sheet to a surface of a glass plate before, during or after processing;
• wherein the glass plate comprises a glass substrate and a low-emissivity layer placed on the glass substrate;
• the protective sheet comprises a substrate layer and a pressure-sensitive adhesive layer on at least one face of the substrate layer, the pressure-sensitive adhesive layer formed from a solvent-based pressure-sensitive adhesive composition containing a pressure-sensitive adhesive in an organic solvent, an active energy ray-curable pressure-sensitive adhesive composition, or a hot-melt pressure-sensitive adhesive composition,
• the pressure-sensitive adhesive layer consists of an acrylic polymer, the acrylic polymer being cross linked by a crosslinking agent,
• the acrylic polymer has a glass transition temperature of −70° C. or higher and 0° C. or lower, and
• the pressure-sensitive adhesive layer has a surface hardness of 0.3 MPa or greater.