摘要 |
A pressure-sensitive adhesive is provided. The adhesive comprises (a) about 50 to 95 weight percent of an ultraviolet radiation polymerized polymer of (i) one or more monomers which are predominantly alkyl acrylate, the alkyl groups of which have an average of 4 to 12 carbon atoms and (ii) about 0 to 15 weight percent of one or more strongly polar copolymerizable monomers or about 0 to 30 weight percent of one or more moderately polar copolymerizable monomers; and (b) about 5 to 50 weight percent of one or more tackifying resins. The tackifying resins are aromatic polymeric resins which have a number average molecular weight of about 300 to 2500, a polydispersity index of less than about 5, a glass transition temperature of about 40 DEG to 120 DEG C., and a solubility parameter of about 7 to 9.5 (cal/cc)-1/2. The adhesive has a monomer conversion factor off at least 98%, and has good storage stability, i.e., losing no more than 70% of its adhesion when aged for a period of two weeks at 70 DEG C.
|