| 摘要 |
Acrylic hot melt pressure sensitive adhesive compositions having a good balance of tack, peel and creep resistance at ambient temperature combined with optical clarity and desirable melt viscosity at elevated temperatures are prepared by copolymerizing acrylic and methacrylic alkyl esters of a non-tertiary alcohol or optionally acids with polymerizable poly methacrylate based macromonomers. The resulting acrylic copolymer has a graft or comb structure in which the acrylic backbone has a low Tg and the pendant macromonomer side chains have a Tg above room temperature. Compounding those acrylic copolymers with tackifiers and plasticizers dramatically improves the balance of pressure sensitive adhesive properties while lowering melt viscosity into a desirable range. The invention provides significant property enhancements even for acrylic copolymers having poor initial peel and shear adhesive properties. Preferably, the acrylic backbone is tailored by judicious selection of acrylic comonomers to allow compounding with several high performance hydrogenated tackifiers and plasticizers that provide water white and clear adhesive formulations while ensuring long term color stability, weatherability and general durability.
|
