A water-dispersible sheet is described that maintains water dispersibility while providing suppressed time degradation of the tacky adhesiveness of a tacky adhesive layer. The water-dispersible sheet has a paper substrate with a multilayer structure. One layer of the multilayer structure is an inner layer that is not in contact with the tacky adhesive layer. Another layer is a surface layer that is in contact with the tacky adhesive layer. The layers independently include mixed pulps of a wood pulp and a refined pulp with an α-cellulose content of 88 % by weight or more. The weight ratio of the layers and the beating degree of the mixed pulps are set in the specific ranges.

The present invention relates to a method of deriving significant factors of rheological properties, which influence folding stability for developing an adhesive with excellent folding stability, and predicting folding stability through the same. It is possible to select an adhesive with excellent folding stability by measuring initial stress and a strain recovery rate as the significant factors, and measuring predicted folding stability (predicted number of times of folding) therefrom.

The present invention relates to a method of deriving significant factors of rheological properties, which influence folding stability for developing an adhesive with excellent folding stability, and predicting folding stability through the same. It is possible to select an adhesive with excellent folding stability by measuring initial stress and a strain recovery rate as the significant factors, and measuring predicted folding stability (predicted number of times of folding) therefrom.

An object of the present invention is to provide an adhesive tape that has high conformability and high adhesion to an adherend, particularly, to a hard adherend and that has high removability such that the adhesive tape, when peeled off, can be easily peeled off if it is stretched not only in the horizontal direction of the adhesive tape but also at an angle, without the need to embrittle the adhesive tape, for example, by heating or by using an organic solvent and without leaving an adhesive on the adherend. The present invention relates to an adhesive tape including an adhesive layer containing a filler. The adhesive tape has a thickness of more than 150 μm and less than 1,500 μm, an elongation at break of 600% to 3,000%, and a tensile strength at break of 2.5 to 80.0 MPa.

Provided is a PSA sheet that can combine bonding reliability and peeling removability, and further can be peeled off without causing deformation or damage to the adherend in various peeling modes. The PSA sheet provided by this invention has a PSA layer. The PSA sheet has a water-peel strength of 2 N/10 mm or less. The PSA sheet further has a stress at 100 % elongation of less than 30 MPa as well as a multiplication product (σf-εf) of fracture stress σf (MPa) and fracture strain εf (%) of 250 or greater.

An electrostatic chuck includes a base plate, a ceramic plate fixed to the base plate and including an electrode embedded in the ceramic plate, and a resin layer bonding the base plate and the ceramic plate and including one or more adhesives. In at least one of the one or more adhesives, a temperature corresponding to an extreme value of a loss tangent in a temperature range of −150° C. to 250° C. is −70° C. or lower.

An electrostatic chuck includes a base plate, a ceramic plate fixed to the base plate and including an electrode embedded in the ceramic plate, and a resin layer bonding the base plate and the ceramic plate and including one or more adhesives. In at least one of the one or more adhesives, a temperature corresponding to an extreme value of a loss tangent in a temperature range of −150° C. to 250° C. is −70° C. or lower.

A pressure-sensitive adhesive sheet including a pressure-sensitive adhesive layer is provided. The pressure-sensitive adhesive layer includes crater portions, each crater portion being concavely formed on an adhesive surface of the pressure-sensitive adhesive layer. A surface of the crater portion has a plurality of through holes.

A pressure-sensitive adhesive sheet including a pressure-sensitive adhesive layer is provided. The pressure-sensitive adhesive layer includes crater portions, each crater portion being concavely formed on an adhesive surface of the pressure-sensitive adhesive layer. A surface of the crater portion has a plurality of through holes.

Provided are a film which can be decorated even against a three-dimensional shape, is excellent in moldability during decoration (adhesion) on an adherend, is able to reduce concaves and convexes with a variety of sizes which the adherend surface has, and makes an appearance quality favorable; and a decorative molded product having the film. The film is a film including a layer containing a thermoplastic resin, wherein when a highest temperature of glass transition temperatures of the film is designated as Tg [+ C], a temperature T [° C.] at which an elongation at break is 50% or more exists in a range of Tg to (Tg+50 [° C.]), and when, with respect to concaves and convexes of an abrasive grain surface of a polyester film sheet having, as an abrasive grain, aluminum oxide having a grain size of 12 μm coated thereon, an amplitude relative to a spatial frequency f is designated as A.sub.1(f); with respect to concaves and convexes of a film surface when adhering the film to the abrasive grain surface at any temperature of the range of Tg to (Tg+50 [° C.]) and a pressure of 0.3 MPa, an amplitude relative to the spatial frequency f is designated as A.sub.2(f); and a ratio of A.sub.2(f) to A.sub.1(f) is designated as ϕ(f)=A.sub.2(f)/A.sub.1(f), a minimum value fc of spatial frequencies where ϕ(f) is 0.1 is 2.0 mm.sup.−1 or less.