Pressure-sensitive adhesive sheet, optical member, and touch panel

A pressure-sensitive adhesive sheet comprising a pressure-sensitive adhesive layer, wherein

• a number of the voids having a diameter of 300 μm or more in the following low pressure test is less than 10, and a number of the voids having a diameter of not less than 50 and less than 300 μm in the following low pressure test is less than 20:
• <Low pressure test>
• A 5 cm×10 cm display panel having a lamination structure of a glass plate/a polarizing plate/a pressure-sensitive adhesive layer/a glass plate is provided as a sample;
• the thickness of the glass plate is 700 μm, the thickness of the polarizing plate is 115 (polarizing plate:
• 95+polarizing plate adhesive:
• 20) μm, and the thickness of the pressure-sensitive adhesive layer is 150 μm;
• and the display panel is left to stand under heating and reduced pressure conditions at 23800 Pa and 65° C. for 8 hours, and after 30 minutes at room temperature under normal pressure, the diameter size and number of voids are visually measured,
• wherein the pressure-sensitive adhesive layer has a 300% tensile residual stress of 5 N/cm2 or less, and
• wherein the pressure-sensitive adhesive layer is formed of a pressure-sensitive adhesive composition comprising an acrylic polymer (A) and a hydrogenated polyolefinic resin (B), or
• wherein the pressure-sensitive adhesive layer is formed of a pressure-sensitive adhesive composition comprising a mixture of monomer components constituting an acrylic polymer (A) or a partially polymerized product of the mixture of monomer components constituting the acrylic polymer (A), and a hydrogenated polyolefinic resin (B).