Multilayer stretch/shrink film

Claim 2

A biaxially oriented heat-shrinkable multilayer stretch film comprising at least a first outer layer, a second outer layer, and a core layer between said first and second outer layers, said first and second outer layers each comprising a blend of between about 20 and about 35 weight % ethylene alpha-olefin plastomer copolymer of density below about 0.90 g/cm 3 , and between about 65 and about 80 weight % VLDPE of density at least 0.912 and below about 0.914 g/cm 3 , and said core layer comprising ethylene alpha-olefin copolymer having a higher melting point than the melting point(s) of either of said first and second outer layers.

Claim 3

A biaxially oriented heat-shrinkable multilayer stretch film according to claim 1 wherein said ethylene alpha-olefin plastomer copolymer comprises between about 22 and about 30 weight % and said VLDPE comprises between about 70 and 78 weight % of the first and second outer layers blend.

Claim 4

A biaxially oriented heat-shrinkable multilayer stretch film according to claim 1 wherein said VLDPE has higher crystallinity than said ethylene alpha-olefin plastomer copolymer.

Claim 5

A biaxially oriented heat-shrinkable multilayer stretch film according to claim 1 wherein said ethylene alpha-olefin plastomer copolymer has a density of about 0.88 g/cm 3 , a melt index of 3.6 g/10 min., an Mw/Mn of about 2.35, and a Vicat softening point of about 54° C.

Claim 6

A biaxially oriented heat-shrinkable multilayer stretch film according to claim 1 wherein said ethylene alpha-olefin plastomer copolymer melts at between about 55° C. and about 85° C.

Claim 7

A biaxially oriented heat-shrinkable multilayer stretch film according to claim 1 wherein said VLDPE has a crystalline melting point between about 117° C. and about 125° C.

Claim 8

A biaxially oriented heat-shrinkable multilayer stretch film according to claim 1 wherein said VLDPE has a yield point and said ethylene alpha-olefin plastomer copolymer does not have a yield point.

Claim 9

A biaxially oriented heat-shrinkable multilayer stretch film according to claim 1 wherein said VLDPE has a broader molecular weight distribution than said ethylene alpha-olefin plastomer.

Claim 10

A biaxially oriented heat-shrinkable multilayer stretch film according to claim 1 wherein said VLDPE has Mw/Mn of at least about 5.

Claim 11

A biaxially oriented heat-shrinkable multilayer stretch film according to claim 1 wherein said ethylene alpha-olefin plastomer has a Mw./Mn below about 2.5.

Claim 12

A biaxially oriented heat-shrinkable multilayer stretch film according to claim 1 wherein said ethylene alpha-olefin copolymer plastomer has a Vicat softening point between about 50 ° C. and 65 ° C.

Claim 13

A biaxially oriented heat-shrinkable multilayer stretch film according to claim 1 wherein said VLDPE has a Vicat softening point between about 78° C. and about 100° C.

Claim 14

A biaxially oriented shrinkable multilayer stretch film according to claim 1 wherein said alpha-olefin plastomer copolymer has density of about 0.88 g/cm 3 and said VLDPE has density of about 0.905 g/cm 3 .

Claim 15

A biaxially oriented heat-shrinkable multilayer stretch film according to claim 1 wherein said core layer is a polyolefin.

Claim 16

A biaxially oriented heat-shrinkable multilayer stretch film according to claim 1 wherein said core layer is VLDPE.

Claim 17

A biaxially oriented heat-shrinkable multilayer stretch film according to claim 1 wherein said core layer is LLDPE.

Claim 18

A biaxially oriented heat-shrinkable multilayer stretch film according to claim 1 wherein said core layer is polypropylene.

Claim 19

A biaxially oriented heat-shrinkable multilayer stretch film according to claim 1 wherein said core layer is a blend of two different ethylene alpha-olefins.

Claim 20

A biaxially oriented heat-shrinkable multilayer stretch film according to claim 1 wherein said core layer is a blend of a lower density ethylene alpha-olefin and a higher density ethylene alpha-olefin.

Claim 21

A biaxially oriented heat-shrinkable multilayer stretch film according to claim 1 wherein said film has at least about 30% shrinkage in both the machine and transverse directions.

Claim 22

A biaxially oriented heat-shrinkable multilayer stretch film according to claim 1 wherein said film has at least about 40% shrinkage in both the machine and transverse directions.

Claim 23

A biaxially oriented heat-shrinkable multilayer stretch film according to claim 1 wherein said film has a permanent deformation of less than about 7% in at least one of the machine and transverse directions.

Claim 24

A biaxially oriented heat-shrinkable multilayer stretch film according to claim 1 wherein said film has a permanent deformation of less than about 6% in both the machine and transverse directions.

Claim 25

A biaxially oriented heat shrinkable multilayer stretch film according to claim 1 wherein said film is an irradiated film.

Claim 26

A biaxially oriented heat shrinkable multilayer stretch film as in claim 1 comprising an intermediate layer between said core layer and each of said outer layers, said intermediate layer comprising a blend of the materials of said core layer and said first and second outer layers.

Claim 27

A biaxially oriented heat-shrinkable film according to claim 1 wherein said core layer comprises VLDPE of density about 0.912 g/cm 3 .

Claim 28

A biaxially oriented heat-shrinkable multilayer stretch film comprising at least a first outer layer, a second outer layer, and a core layer between said first and second outer layers, said first and second outer layers each comprising a blend of between about 20 and about 35 wt. % ethylene alpha-olefin plastomer copolymer of density below about 0.90 g/cm 3 , and between about 65 and about 80 wt. % VLDPE wherein said VLDPE comprises a blend of a first ethylene alpha olefin having a density of about 0.912 g/cm 2 and a second ethylene alpha olefin which is a butene comonomer having a density of about 0.900 g/cm 2 , a melt index of about 3.5, a melting point of about 92° C. and an Mw/Mn ratio of about 2 and said core layer comprises ethylene alpha-olefin copolymers having a high melting point than the melting point of either of each first and second outer layers.

Claim 29

A biaxially oriented heat-shrinkable multilayer stretch film comprising at least a first outer layer, a second outer layer, and a core layer between said first and second outer layers, said first and second outer layers each comprising a blend of between about 20 and about 35 wt. % ethylene alpha-olefin plastomer copolymer of density below about 0.90 g/cm 3 , and between about 65 and about 80 wt. % VLDPE wherein said VLDPE comprises a blend of a first ethylene alpha olefin having a density of about 0.912 g/cm 2 and a second ethylene alpha olefin which is a butene comonomer having a density of about 0.900 g/cm 2 , a melt index of about 3.5, a melting point of about 92° C. and an Mw/Mn ratio of about 2 and said core layer comprises ethylene alpha-olefin copolymers having a high melting point than the melting point of either of each first and second outer layers.

Claim 30

A biaxially oriented heat-shrinkable multilayer film according to claim 27 wherein said first ethylene alpha olefin comprises between about 35 and about 40 wt. % and said second ethylene alpha olefin comprises between about 27 and about 32 wt. % of said blend.

Claim 31

A biaxially oriented heat-shrinkable multilayer film according to claim 27 wherein said second ethylene alpha olefin is Exact type 3010C/3027.