Hot-Melt Adhesive Compositions Based on Olefin Co-Polymers
The present invention relates to a new type of polyolefin based hot-melt adhesive and methods for their production. More particularly, it relates to a new type of hot-melt adhesive comprising propylene co-polymers and possessing a favorable balance of cohesive strength, adhesion properties, and processibility, which render them especially well-suited for some hot-melt adhesive applications, for example, as elastic attachment adhesives.
1 ) A composition of matter useful as an adhesive, which comprises:
a) about 30% to about 90% by weight, based on the total weight of said composition, of a polypropylene component selected from the group consisting of: polypropylene homopolymers, polypropylene co-polymers, and any mixtures of the foregoing;
b) about 10% to about 60% by weight, based on the total weight of said composition, of a tackifier resins component;
c) about 0% to about 40% by weight, based on the total weight of said composition, of a functionalized polymer component; and
d) about 0.01% to about 1% by weight, based on the total weight of said composition, of a stabilizer(s) component.
2 ) A composition according to claim 1 wherein the polypropylene component is a co-polymer of propylene and at least one other C 2 -C 10 olefin monomer, wherein the co-monomer content in said propylene co-polymer is any amount between about 0.5% and about 60% by weight, based on the total weight of the co-polymer.
3 ) A composition according to claim 1 wherein said co-polymer has a degree of crystallinity as measured by method ASTM D-3417 of between about 0.2 and about 35 Joules per gram.
4 ) A composition according to claim 1 wherein said co-polymer has a weight-average molecular weight of between about 10,000 and about 1,000,000.
5 ) A composition according to claim 1 wherein said co-polymer has a melt viscosity in the range of between about 500 cps to about 1,000,000 cps @ 375° F.
6 ) A composition according to claim 1 wherein said tackifier resins component comprises one or more resins derived from a material selected from the group consisting of: hydrocarbons, rosin, rosin esters, synthetic poly-terpenes and natural terpenes.
7 ) A composition according to claim 1 wherein said tackifier resins component is present in any amount between about 10% to about 60% by weight based on the total weight of said composition.
8 ) A composition according to claim 1 wherein said functionalized polymer comprises a maleic acid anhydride graft co-polymer of polypropylene.
9 ) A composition according to claim 1 wherein said functionalized polymer comprises the reaction product of a maleic acid anhydride graft co-polymer of polypropylene with a material having an active hydrogen atom.
10 ) A composition according to claim 9 wherein said material having an active hydrogen atom is selected from the group consisting of: amines, polyalkylene amines, and polyoxyalkylene amines.
11 ) A composition according to claim 1 wherein said stabilizer component comprises one or more materials selected from the group consisting of phenols, hindered phenols, and phosphates.
12 ) A composition according to claim 1 wherein said composition has a melt viscosity of between about 500 cps and about 80,000 cps @ 375° C.
13 ) A composition according to claim 1 wherein said composition has a melt viscosity of between about 1500 cps and about 10,000 cps @ 375° C.
14 ) A composition according to claim 1 wherein said composition has a tensile strength of between about 50 and about 400 psi.
15 ) A composition according to claim 1 wherein said composition has a tensile elongation of at least 50%.
16 ) A composition according to claim 1 wherein said composition has a tensile elongation of at least 75%.
17 ) A composition according to claim 2 wherein said other olefin monomer is selected from the group consisting of: 1-butene and 1-octene.
18 ) A garment which is suitable to be worn by a person which comprises an adhesive according to claim 1 .
19 ) A garment according to claim 18 wherein said garment comprises a strand of elastic material attached to a non-woven polyolefin-containing fabric.
20 ) A laminated structure which comprises an adhesive according to claim 1 .