Abstract: This invention provides a protective sheet for glass etching, having excellent etching solution penetration resistance, non-contaminating property and peeling efficiency. The protective sheet comprises a substrate and a PSA layer provided on one face of the substrate, such that, when the protective sheet is adhered to a non-etching area when etching glass, it protects the non-etching area from an etching solution. The PSA layer is constituted with a PSA having a gel fraction of 60% or higher. The PSA is an acrylic PSA comprising an acrylic polymer as a primary component. The acrylic polymer is synthesized by polymerizing starting monomers comprising, as a primary monomer, a monomer represented by a formula: CH2?CR1COOR2 (R1 is a hydrogen atom or a methyl group, and R2 is an alkyl group). The primary monomer comprises as a primary component a monomer with R2 being an alkyl group having 6 or more carbons.

Abstract: A protective sheet is provided that achieves both a high level of performance as a protective sheet (particularly a protective sheet for masking during plating) and an excellent ease of use. The protective sheet includes a substrate and a pressure-sensitive adhesive (PSA) layer which is provided on one side of the substrate. The PSA layer is formed of an acrylic PSA composition which includes a crosslinking agent and a crosslinking accelerator. The sum DS80 of a flexural rigidity DM80 of the protective sheet at 80° C. in the machine direction and a flexural rigidity DT80 of the protective sheet at 80° C. in the transverse direction is from 0.1×10?6 Pa·m3 to 1.2×10?6 Pa·m3. The PSA layer has a storage modulus G? at 100° C., as measured at a frequency of 1 Hz, of from 0.230×106 Pa to 10×106 Pa.

Abstract: A protective sheet (for example, a protective sheet for masking during plating) is provided that has an excellent balance of adherence to the surface of an adherend and easy releasability when heat and pressure bonded. The protective sheet includes a substrate and a pressure-sensitive adhesive (PSA) layer which is provided on one side of the substrate. The PSA layer is thermoplastic. When the protective sheet is pressure bonded to a polyimide film at a temperature of 120° C. and a pressure of 0.34 MPa for a pressing time of 5 seconds, the protective sheet has a peel strength PSHP, as measured by peeling the protective sheet from the polyimide film at a temperature of 25° C., a peel rate of 5 m/min and a peel angle of 180°, of from 0.05 N/10 mm to 1.0 N/10 mm.

Abstract: A protective sheet 10 is provided which exhibits excellent properties as a protective sheet and a satisfactory handleability. The protective sheet 10 is formed of a substrate 1 which is a plastic film and a pressure-sensitive adhesive layer 2 which is provided on one side of the substrate, and satisfies all of the following properties: (A) the total flexural rigidity DTrt at 25° C. in a first direction and a second direction is from 3.0×10?6 to 20×10?6 Pa·m3; (B) the total flexural rigidity DTht at 80° C. is from 0.10×10?6 to 1.2×10?6 Pa·m3; (C) the flexural rigidity ratio DR, defined as DTrt/DTht, is from 3.0 to 80; and (D) the tensions T1rt and T2rt at 25° C. when stretched 10% in the first direction and the second direction respectively are at least 5.0 N/10 mm.