Abstract: A pressure-sensitive adhesive composition includes 100 parts by mass of a rubber component containing 40 to 93 mass % of a butyl rubber and 7 to 60 mass % of a polyisobutylene and 82 to 128 parts by mass of a softener having a kinetic viscosity at 40° C. of 100 to 9,000 mm2/s.

Abstract: A waterproof screw includes a screw member including a head portion and a shank portion and a sealing material covering the circumference of the shank portion. In the sealing material, the tackiness of a surface at the outer side in a radial direction of the shank portion is lower than that of a surface at the inner side in the radial direction thereof and the inner side in the radial direction of the sealing material has a shear storage elastic modulus G? at 25° C. measured at a frequency of 1 Hz of 50000 Pa or less.

Abstract: A pressure-sensitive adhesive composition includes 100 parts by mass of a rubber component containing 40 to 93 mass % of a butyl rubber and 7 to 60 mass % of a polyisobutylene and 82 to 128 parts by mass of a softener having a kinetic viscosity at 40° C. of 100 to 9000 mm2/s.

Abstract: A waterproof screw includes a screw member including a head portion and a shank portion and a sealing material covering the circumference of the shank portion. The sealing material has a shear storage elastic modulus G? at 25° C. and a frequency of 1 Hz of 50000 Pa or less.

Abstract: A sealing composition containing a rubber component and polyolefin, wherein the rubber component contains butyl rubber and polyisobutylene having a viscosity average molecular weight in the range of 500,000 to 3,000,000, the mixing ratio of the rubber component to 100 parts by weight of the total amount of the rubber component and the polyolefin is in the range of 40 to 90 parts by weight, and the sealing composition contains 0 to 30 parts by weight of a hygroscopic compound with respect to 100 parts by weight of the total amount of the rubber component.