ADHESIVE COMPOSITION AND ADHESIVE TAPE

To provide an adhesive composition capable of forming an adhesive layer that exhibits light peelability from an adherend in the initial stage of bonding, displays high adhesive strength after heating, efficiently inhibits the entry of bubbles from the adherend, and ensures that the initial-stage light peelability of an adhesive tape from its own backing remains stable over time.SOLUTION: An adhesive composition includes a polymer A with a Tg of lower than 0°C, which includes a hydroxy group-containing monomer unit, a polymer B which includes 0.1-10 mass% of an organosiloxane skeleton-containing monomer unit, more than 50 mass % and 85 mass% or less of an alkyl (meth)acrylate monomer unit where the homopolymer has a Tg of 40°C or higher, and 0.01-0.5 mass% of a (meth)acrylic acid unit, wherein the Mw is 10000-400000 and Tg is 0°C or higher, and an HMDI compound and/or XDI compound. In the polymer B, the organosiloxane skeleton-containing monomer unit has an Mn of 4000 or more and less than 20000. The content of the polymer B is more than 20 pts.mass to 100 pts.mass or less relative to 100 pts.mass of the polymer A.SELECTED DRAWING: None 【課題】被着体に対して、貼り合わせ初期には軽剥離性を示し、かつ、加熱後は高い粘着力を示し、被着体から発生する気泡の混入を良好に抑制でき、粘着テープの自背面に対する貼り合わせ初期の軽剥離性が経時で損なわれ難い粘着剤層を形成できる粘着剤組成物の提供。【解決手段】水酸基含有単量体単位を含み、Ｔｇが０℃未満の重合体Ａと、オルガノシロキサン骨格含有単量体単位を０．１～１０質量％、単独重合体のＴｇが４０℃以上の（メタ）アクリル酸アルキルエステル単量体単位を５０超８５質量％以下、及び（メタ）アクリル酸単位を０．０１～０．５質量％含み、Ｍｗが１万～４０万、Ｔｇが０℃以上の重合体Ｂと、ＨＭＤＩ系化合物及び／又はＸＤＩ系化合物とを含み、重合体Ｂにおけるオルガノシロキサン骨格含有単量体のＭｎが４０００以上２００００未満であり、重合体Ｂの含有量が重合体Ａ１００質量部に対して２０超１００質量部以下の粘着剤組成物。【選択図】なし