| 摘要 |
Provided are: an acrylic-based hot-melt adhesive that is superior in terms of both hot-melt coating characteristics and holding strength, is favorable for application in hot-melt coating methods that coat at a high speed at low temperatures, has superior transparency and weather resistance, and furthermore has superior adhesion at low temperatures; and a block copolymer favorable for use with respect to same. The present invention produces an adhesive containing a block copolymer having at least one structure represented by the general formula -[A1]-[B/A2]- (wherein: [A1] indicates a polymer block comprising a structural unit derived from a methacrylic ester (A1); [B/A2] indicates a copolymer block comprising a structural unit derived from an acrylic ester (B) and a structural unit derived from a methacrylic ester (A2); and the copolymer block [B/A2] has a gradient copolymer block section at which the copolymer ratio of the methacrylic ester (A2) continues to increase from the section of bonding to the copolymer block [A1]), having a total content of structural units derived from the methacrylic ester (A1) and the methacrylic ester (A2) of 5-60 mass%, having a weight average molecular weight (Mw) of 30,000-300,000, and having a molecular weight distribution (Mw/Mn) of 1.0-1.5. |
