Interpolymers suitable for use in hot melt adhesives and processes to prepare the same
View Patent ↗The present invention relates to an ethylene/α-olefin interpolymer product comprising at least one α-olefin interpolymerized with ethylene and, characterized in at least one aspect, as having improved properties when utilized in a hot melt adhesive formulation. The invention also relates to a process for manufacturing the interpolymer product wherein the process comprises employing two or more single site catalyst systems in at least one reaction environment (or reactor) and wherein the at least two catalyst systems have (a) different comonomer incorporation capabilities or reactivities and/or (b) different termination kinetics, both when measured under the same polymerization conditions. The interpolymer products are useful, for example, in applications such as hot melt adhesives, and also for impact, bitumen and asphalt modification, adhesives, dispersions or latexes and fabricated articles such as, but not limited to, foams, films, sheet, moldings, thermoforms, profiles and fibers.
1. A process of making an ethylene interpolymer, said process comprising:
i) contacting one or more olefinic monomers in the presence of at least two catalysts, one having a reactivity ratio r 1 H , and the other a reactivity ratio r 1 L , and
ii) effectuating the polymerization of the olefinic monomers in a reactor, to obtain an olefin polymer, and
wherein each of r 1 H and r 1 L is from 1 to 200, and r 1 H /r 1 L , is from 0.03 to 30, and/or
wherein one catalyst is capable of producing a first polymer, with a high molecular weight (M wH ), from the monomers, under selected polymerization conditions, and the other catalyst is capable of producing a second polymer with, relative to the first polymer, a low molecular weight (M wL ), from the same monomers, under substantially the same polymerization conditions, and wherein M wH /M wL is from 1.5 to 20, and
wherein said interpolymer has a Brookfield Viscosity (measured at 149° C./300° F.) from 500 to 7,000 cP, and wherein said interpolymer is a copolymer of ethylene/propylene, ethylene/1-butene, ethylene/4-methyl-1-pentene, ethylene/1-pentene, ethylene/1-hexene or ethylene/1-octene.
2. The process of claim 1 , wherein the catalysts are single site catalysts.
3. The process of claim 1 , wherein the catalysts are metallocene catalysts.
4. The process of claim 3 , wherein at least one of the metallocene catalysts is a constrained geometry catalyst.
5. The process of claim 4 , wherein said at least one constrained geometry catalyst is (C 5 Me 4 SiMe 2 N t Bu)Ti(η 4 -1,3-pentadiene).
6. The process of claim 1 , wherein the catalysts are (C 5 Me 4 SiMe 2 N t Bu)Ti(η 4 -1,3-pentadiene) and (1H-cyclopenta[1]-phenanthrene-2-yl)dimethyl(t-butylamido) silanetitanium dimethyl.
7. The process of claim 1 , wherein the catalysts are (C 5 Me 4 SiMe 2 N t Bu)ZrMe 2 and (C 5 Me 4 SiMe 2 N t Bu)Ti(η 4 -1,3-pentadiene).
8. The process of claim 1 , wherein the catalysts are [N-(1,1-dimethylethyl)-1,1-dimethyl-1[(1,2,3,4,5-η)-3,4-diphenyl-2,4-cyclopentadienyl-1-yl]silanaminato(2)-κN]- dimethyl-titanium and (C5Me 4 SiMe 2 N t Bu)Ti(η 4 -1,3-pentadiene).
9. The process of claim 1 , wherein the catalysts are [N-(1,1-dimethylethyl)-1,1-dimethyl-1[(1,2,3,4,5-η)3,4-diphenyl-2,4-cyclopentadienyl-1-yl]silanaminato(2)-κN]- dimethyl-titanium and (1H-cyclopenta[1]-phenanthrene-2-yl)dimethyl (t-butylamido) silanetitanium dimethyl.