| abstract |
Provided is a water-based pressure-sensitive adhesive composition which is highly environmentally harmless, needs no aging, can be of the one-pack type that is highly convenient, and is capable of forming pressure-sensitive adhesive layers which have no problems concerning aged adhesive force as well as initial adhesive force and exhibit satisfactory removability. The removable water-based pressure-sensitive adhesive composition comprises, as a main component, an emulsion [A] of a (meth)acrylic acid ester copolymer having carboxy groups or hydroxy groups and having a constituent unit that reacts with a crosslinking agent and contains, functioning as a crosslinking aid, an emulsion [B] of a (meth)acrylic acid ester copolymer in an amount of 0.6 parts by mass or larger on a solid basis per 100 parts by mass of the solid matter of the emulsion [A], the copolymer in the emulsion [B] having a peculiar structure that makes the copolymer dissolve in water upon neutralization so that a particle diameter measurement through particle diameter distribution analysis at a pH of 6.5-7.5 is impossible. The water-based pressure-sensitive adhesive composition further contains a crosslinking agent [C], which is a hydrazide compound soluble or dispersible in water. |