Abstract: A pressure sensitive adhesive sheet for bonding two rigid plates together, at least one of the two rigid plates having irregularities on a surface on a side to be bonded to the other rigid plate, the pressure sensitive adhesive sheet containing: a composite pressure sensitive adhesive layer containing an optically functional pressure sensitive adhesive layer and a transparent pressure sensitive adhesive layer that does not have an optical function of the optically functional pressure sensitive adhesive layer; and a release sheet laminated on the transparent pressure sensitive adhesive layer in the composite pressure sensitive adhesive layer, the composite pressure sensitive adhesive layer having a straightforward transmittance of 90% or less for light rays having a wavelength of 550 nm. According to such a pressure sensitive adhesive sheet, uneven optical function in the pressure sensitive adhesive layers can be suppressed.

Abstract: A pressure sensitive adhesive used in optical applications. The pressure sensitive adhesive contains a modified cyclodextrin having a degree of modification of more than 2.5 and 3.0 or less. The gel fraction of the pressure sensitive adhesive is 1.0% or more. Such a pressure sensitive adhesive is excellent in the durability even at high temperatures.

Abstract: A pressure sensitive adhesive sheet having a pressure sensitive adhesive layer that includes at least one colored pressure sensitive adhesive layer, the colored pressure sensitive adhesive layer having a pressure sensitive adhesive that contains a colorant, the pressure sensitive adhesive layer having a lightness L* of 90 or less as defined by a CIE 1976 L*a*b* color system, the pressure sensitive adhesive layer having a total luminous transmittance of 3% or more and a thermal conductivity of 0.1 W/m·K or more.

Abstract: An adhesive sheet (1) comprising an adhesive layer (11) composed of an adhesive having active energy ray curability and ultraviolet ray absorbability, wherein when one surface of the adhesive layer (11) is irradiated with ultraviolet rays having a light amount of 2000 mJ/cm2 to cure the adhesive layer (11) and an infrared absorption spectrum is then measured by a total reflection measurement method for each of an irradiated surface and a non-irradiated surface, the maximum value of the absolute value of absorbance is 0.0001 to 0.