Tackified Polyolefin Adhesive Compositions

摘要

The present invention is related to adhesive compositions comprising a polymer blend of at least two different propylene-based polymers and one or more tackifiers. The polymer blend has a melt viscosity of about 900 cP to about 19,000 cP. When subjected to Temperature Rising Elution Fractionation, the polymer blend exhibits a first fraction that is soluble at −15° C. in xylene, the first fraction having an isotactic (mm) triad tacticity of about 70 mol % to about 90 mol %; and a second fraction that is insoluble or less soluble than the first fraction at −15° C. in xylene, the second fraction having an isotactic (mm) triad tacticity of about 85 mol % to about 98 mol %. The tackifier has a softening point, as determined by ASTM E-28, of about 85 to about 135° C. and an aromaticity of about 2 to about 12 mol % aromatic protons.

主权项

1. An adhesive composition comprising:
a polymer blend comprising
a first propylene-based polymer, wherein the first propylene-based polymer is a homopolymer of propylene or a copolymer of propylene and ethylene or a C4 to C10 alpha-olefin;a second propylene-based polymer, wherein the second propylene-based polymer is a homopolymer of propylene or a copolymer of propylene and ethylene or a C4 to C10 alpha-olefin; wherein the second propylene-based polymer is different than the first propylene-based polymer;wherein the polymer blend has a melt viscosity, measured at 190° C. of about 900 cP to about 19,000 cP and wherein, when subjected to Temperature Rising Elution Fractionation, the polymer blend exhibits: a first fraction that is soluble at −15° C. in xylene, the first fraction having an isotactic (mm) triad tacticity of about 70 mol % to about 90 mol %; and a second fraction that is insoluble at −15° C. in xylene, the second fraction having an isotactic (mm) triad tacticity of about 85 mol % to about 98 mol %; and a tackifier having a softening point, as determined by ASTM E-28, of about 85 to about 135° C. and an aromaticity of about 2 to about 12 mol % aromatic protons.