EXTRUDABLE HOT-MELT PRESSURE-SENSITIVE ADHESIVES FOR RESEALABLE PACKAGING HAVING IMPROVED ORGANOLEPTIC PROPERTIES

摘要

Hot-melt pressure-sensitive adhesive composition with MFI of 0.01 to 200 g/10 minutes containing:
45 to 70% by weight of styrene block copolymers of SIS type with an SI diblock content of 30 to 90% and a content of styrene units of 10 to 40%; and30 to 55% by weight of a tackifying resin having a softening temperature of 5 to 150° C., and obtained by a process containing:
polymerizing
a composition (i) essentially composed of unsaturated hydrocarbons having 9 carbon atoms, ora composition (ii) essentially composed of dicyclopentadiene and of its derivatives having 10 carbon atoms; thenhydrogenating the polymer.;Multilayer film containing an adhesive layer composed of the composition with a thickness of 7 to 50 μm.;Process for making the film by coextrusion.;Using the said film for resealable cartons.

主权项

1. Hot-melt pressure-sensitive adhesive composition a having a melt flow index ranging from 0.01 to 200 g/10 minutes and comprising, on the basis of the total weight of the said composition a:
from 45 to 70% by weight of a composition a1 of styrene block copolymers comprising at least one elastomer block, the said composition a1 being composed, on the basis of its total weight:
of 30 to 90% by weight of at least one diblock copolymer of Styrene-Isoprene (SI) type, andof 10 to 70% by weight of at least one Styrene-Isoprene-Styrene (SIS) linear triblock copolymer;the total content of styrene units of the said composition a1 varying from 10 to 40% by weight on the basis of the total weight of a1; and
from 30 to 55% by weight of at least one tackifying resin a2 having a softening temperature of between 5 and 150° C. and obtained by a process comprising:
a first stage of polymerization of a composition chosen from:
a composition (i) essentially composed of unsaturated hydrocarbons having 9 carbon atoms, ora composition (ii) essentially composed of dicyclopentadiene and of its derivatives having 10 carbon atoms; thena second stage of hydrogenation of the polymer thus obtained.