Metallocene-Produced Polyethylene For Glossy Plastic Containers
A high gloss plastic container prepared from a metallocene-produced polyethylene having a density of from 0.930 to 0.966 g/cm 3 and a melt index MI2 of from 0.5 to 2.5 g/10 min.
1 - 9 . (canceled)
10 . A process for forming a plastic container comprising:
preparing a catalyst system comprising
a metallocene catalyst represented by the following formula
(C 5 R′ k ) g R″ s (C 5 R′ k )MQ 3-g
wherein (C 5 R′ k ) is a cyclopentadienyl or substituted cyclopentadienyl, each R′ is the same or different and is hydrogen or a hydrocarbyl radical such as alkyl, alkenyl, aryl, alkylaryl, or arlalkyl radical containing from 1 to 20 carbon atoms or two carbon atoms are joined together to form a C 4 -C 6 ring, R″ is a C 1 -C 4 alkylene radical, a dialkyl germanium or silicon or siloxane, or an alkyl phosphine or amine radical bridging two (C 5 R′ k ) rings, Q is a hydrocarbyl radical such as aryl, alkyl, alkenyl, alkylaryl, or aryl alkyl radical having from 1-20 carbon atoms, hydrocarboxy radical having 1-20 carbon atoms or halogen and can be the same or different from each other, and M is a group 4b, 5b, or 6b transition metal;
contacting the metallocene catalyst with at least one monomer, wherein the at least one monomer comprises ethylene to form an ethylene polymer;
blow molding the ethylene polymer to form the container, wherein the container has a container wall formed of at least one layer having an external surface a gloss of at least 40.
11 . The process of claim 10 wherein the layer comprises a polyethylene homopolymer.
12 . The process of claim 10 wherein the layer comprises a copolymer of ethylene and a higher molecular weight α-olefin.
13 . The process of claim 10 wherein said higher molecular weight α-olefin is a C 4 -C 8 α-olefin.
14 . The process of claim 13 wherein said higher molecular weight α-olefin is hexene.
15 . The process of claim 10 wherein the ethylene polymer has a density within the range of 0.930 to 0.966 g/cm 3 and a melt index MI 2 within the range of 0.5 to 2.5 g/10 min.
16 . The process of claim 10 , wherein the catalyst system further comprises an alumoxane cocatalyst.
17 . The process of claim 10 , wherein the catalyst system further comprises an aluminumalkyl.
18 . The process of claim 17 , wherein the aluminumalkyl is a trialkylaluminum.
19 . The process of claim 10 , wherein the metallocene catalyst is a bridged bis indenyl or a bridged bis tetrahydroindenyl metallocene catalyst.
20 . The process of claim 10 , wherein the process of blow molding further comprises incorporating a fluoroelastomer into the ethylene polymer.
21 . The process of claim 10 , wherein the metallocene catalyst is incorporated into the ethylene polymer.
22 . The process of claim 10 , wherein the layer has a swell in diameter of less than 40 mm as measured by a Gottfert 2002 capillary rheometer at 210° F.