초록 ▼

A process of making a biaxially-oriented multilayer film, comprises extruding a tubular multilayer tape and inflating the tape so that the tape is biaxially oriented by stretching in the transverse direction and machine direction at the same time, so that a tubular multilayer film is formed. The tub

A process of making a biaxially-oriented multilayer film, comprises extruding a tubular multilayer tape and inflating the tape so that the tape is biaxially oriented by stretching in the transverse direction and machine direction at the same time, so that a tubular multilayer film is formed. The tubular multilayer tape comprises: (i) a first layer comprising a composition comprising a first polyamide and at least one member selected from the group consisting of a first polyolefin and a second polyamide, wherein the first polyamide comprises at least one member selected from the group consisting of nylon 6, nylon 66, and nylon 6/66, and wherein the first polyolefin and the second polyamide each has a different crystal structure than the first polyamide, and wherein the first layer has a thickness of less than about 15 percent, based on a total thickness of the tape; (ii) a second layer comprising a second polyolefin; (iii) a third layer which is an O.sub.2 -barrier layer comprising at least one member selected from the group consisting of ethylene/vinyl alcohol copolymer, polyvinylidene chloride, and polyalkylene carbonate, the third film layer having a thickness of less than about 15 percent, based on a total thickness of the tape; and (iv) a fourth layer comprising a third polyolefin.

대표청구항 ▼

[What is claimed is:] [1.](A) extruding a tubular multilayer tape comprising:(i) a first layer comprising a composition consisting essentially of a first polyamide and a second polyamide, wherein the first polyamide is a crystalline polyamide and wherein the second polyamide is a crystalline copolya

[What is claimed is:] [1.](A) extruding a tubular multilayer tape comprising:(i) a first layer comprising a composition consisting essentially of a first polyamide and a second polyamide, wherein the first polyamide is a crystalline polyamide and wherein the second polyamide is a crystalline copolyamide, wherein the second polyamide has a different crystal structure than the first polyamide, and the first layer has a thickness of from about 2 to 12 percent, based on a total thickness of the tape;(ii) a second layer comprising a first polyolefin;(iii) a third layer which is an O.sub.2 -barrier layer comprising at least one member selected from the group consisting of ethylene/vinyl alcohol copolymer, polyvinylidene chloride, and polyalkylene carbonate, the third film layer having a thickness of less than about 15 percent, based on a total thickness of the tape;(iv) a fourth layer comprising a second polyolefin;(B) inflating the tape so that the tape is biaxially oriented by stretching in a transverse direction and machine direction, so that a tubular multilayer film is formed.