Oriented evoh/nylon blend film

Claim 2

A film of, or a laminate structure including as an element thereof, a heterogenous melt blended composition consisting essentially of: (1) a polyamide, and (2) from 1 to 90% by weight of an ethylene-vinyl alcohol copolymer having 15 to 65 mol percent ethylene; in the absence of a plasticizer, said composition having been processed at a temperature of from about 225° C. to 252° C. and being substantially free of cross-linking.

Claim 3

A molecularly oriented multilayer film having good strength, toughness and oxygen barrier properties comprising: (a) a first layer produced from a synthetic resin blend of about 90 to 10 weight percent of a nylon resin, conversely, about 10 to 90 weight percent of ethylene vinyl alcohol copolymer having a molecular weight of about 15,000 to 30,000 and a melting point temperature of about 325° to 375° F., and up to about 25 percent, based upon the weight of said nylon resin, of a plasticizer therefor, said blend being processable at a temperature approximately the processing temperature of said copolymer and below the temperature at which any substantial amount of degradation would occur therein under appropriate conditions for extrusion; and (b) at least a second layer having a composition different from that of said first layer, said film having been molecularly oriented by stretching, in at least one direction, at ratio of at least 2:1.

Claim 4

A molecularly oriented multilayer film having good strength, toughness and oxygen barrier properties comprising: (a) a first layer produced from a synthetic resin blend of about 90 to 10 weight percent of a nylon resin, conversely, about 10 to 90 weight percent of ethylene vinyl alcohol copolymer having a molecular weight of about 15,000 to 30,000 and a melting point temperature of about 325° to 375° F., and up to about 25 percent, based upon the weight of said nylon resin, of a plasticizer therefor, said blend being processable at a temperature approximately the processing temperature of said copolymer and below the temperature at which any substantial amount of degradation would occur therein under appropriate conditions for extrusion; and (b) at least a second layer having a composition different from that of said first layer, said film having been molecularly oriented by stretching, in at least one direction, at ratio of at least 2:1.

Claim 5

The film of claim 2 wherein said second layer comprises a resin selected from the group consisting of ethylene/organic acid ester copolymers, polyolefins, film-forming nylons, ionomer resins, partially hydrolyzed ethylene/vinyl acetate copolymer adhesives, and anhydride-modified polyolefin adhesives.

Claim 6

The film of claim 3 wherein said film additionally includes a third layer of a composition different from that of said first layer, said first layer constituting a core interposed between said second and third layers.

Claim 7

The film of claim 4 wherein said first layer comprise an EVOH/nylon copolymer blend, and said second and third layers comprise film-forming nylon homopolymer resins.

Claim 8

The film of claim 4 wherein said second and third layers comprise ethylene/vinyl acetate copolymer resins.

Claim 9

A molecularly oriented multilayer nylon film having good strength, toughness and oxygen barrier properties comprising a coeoxtrudate of: a core layer produced from a synthetic resin blend of about 90 to 10 weight percent of a first nylon resin, about 10 to 90 weight percent of ethylene vinyl alcohol copolymer having a molecular weight of about 15,000 to 30,000 and a melting point temperature of about 325° to 375° F., and up to about 25 percent, based upon the weight of said first nylon resin, of a plasticizer therefor, said blend being processable at a temperature approximately the processing temperature of said copolymer and below the temperature at which any substantial amount of degradation would occur therein under appropriate conditions for extrusion; and an outer layer on each side of said core layer and in direct surface contact therewith, said outer layers being comprised of a second, film-forming nylon resin of a composition different from said first nylon resin, said film having been molecularly oriented by stretching in at least one direction at ratio of at least 2:1.

Claim 10

A molecularly oriented multilayer nylon film having good strength, toughness and oxygen barrier properties comprising a coeoxtrudate of: a core layer produced from a synthetic resin blend of about 90 to 10 weight percent of a first nylon resin, about 10 to 90 weight percent of ethylene vinyl alcohol copolymer having a molecular weight of about 15,000 to 30,000 and a melting point temperature of about 325° to 375° F., and up to about 25 percent, based upon the weight of said first nylon resin, of a plasticizer therefor, said blend being processable at a temperature approximately the processing temperature of said copolymer and below the temperature at which any substantial amount of degradation would occur therein under appropriate conditions for extrusion; and an outer layer on each side of said core layer and in direct surface contact therewith, said outer layers being comprised of a second, film-forming nylon resin of a composition different from said first nylon resin, said film having been molecularly oriented by stretching in at least one direction at ratio of at least 2:1.

Claim 11

The film of claim 7 wherein said blend comprises about 75 to 25 weight percent of said first nylon resin, about 25 to 75 weight percent of said ethylene vinyl alcohol copolymer, and at least about 2 percent of said plasticizer, based upon the weight of said first nylon resin, said first nylon resin having a molecular weight of about 20,000 to 30,000 and a melting point temperature of about 415° to 440° F., and said plasticizer being effective to lower the processing temperature of said nylon resin to approximately that of said copolymer.

Claim 12

The film of claim 7 wherein said ethylene vinyl alcohol copolymer has a molecular weight of about 18,000 to 25,000, and wherein said processing temperature is about 400° F.

Claim 13

The film of claim 8 wherein said plasticizer is selected from the group consisting of long chain fatty acid amides, aromatic sulfonamides, and polyamides and copolyamides having a molecular weight of about 5,000 to 25,000 and a melting point temperature below about 400° F.

Claim 14

The film of claim 10 wherein said plasticizer is selected from the class consisting of lauramide, o,p-toluenesulfonamide, N-ethyl-o,p-toluenesulfonamide, and polyamides of 7,000 to 10,000 molecular weight.

Claim 15

The film of claim 7 wherein at least a portion of said first nylon resin in said blend is an ingredient selected from the group consisting of nylon random copolymers, nylon block copolymers, nylon alloys and nylon homopolymers, said ingredient having a melting point temperature below about 400° F.

Claim 16

The film of claim 12 wherein said group comprises nylon 12, nylon 6,12, nylon 6,36, nylon 6,6, nylon 6/polyolefin alloys, and nylon 12/polyether or polyolefin block copolymers.

Claim 17

The film of claim 12 wherein said core layer comprises an EVON/nylon copolymer blend, and said outer layers comprise nylon homopolymer resins.

Claim 18

A laminate structure comprising a layer of a first resin having a composition different from that of the melt blended composition described wherein; and at least one adjacent layer of a heterogeneous melot blended composition consisting essentially of: a polyamide; and from 10 to 90% by weight of an ethylene vinyl alcohol copolymer having 10 to 45 mol percent ethylene, in the absence of plasticizer, wherein there are regions of ethylene vinyl alcohol copolymer having an average diameter of less than 500 angstroms in the polyamide, said composition having been processed at a temperature of from about 225° C. to 252° C. and being substantially free from crosslinking.

Claim 19

A laminate structure comprising a layer of a first resin having a composition different from that of the melt blended composition described wherein; and at least one adjacent layer of a heterogeneous melot blended composition consisting essentially of: a polyamide; and from 10 to 90% by weight of an ethylene vinyl alcohol copolymer having 10 to 45 mol percent ethylene, in the absence of plasticizer, wherein there are regions of ethylene vinyl alcohol copolymer having an average diameter of less than 500 angstroms in the polyamide, said composition having been processed at a temperature of from about 225° C. to 252° C. and being substantially free from crosslinking.

Claim 20

The laminate as recited in claim 15 wherein the polyamide is polyepsilocaprolactam.

Claim 21

The laminate as recited in claim 16 wherein there is from 10 to 30 percent ethylene vinyl alcohol copolymer in the layer containing polyepsiloncaprolactam.

Claim 22

The laminate as recited in claim 15 wherein there is from 10 to 50 percent ethylene vinyl alcohol copolymer in the layer containing the polyamide.

Claim 23

A film having a thickness of from about 0.4 mils to about 20 mils made from a heterogeneous melt blended composition consisting essentially of: a polyamide; and from 10 to 90% by weight of an ethylene vinyl alcohol copolymer having 20 to 45 mol percent ethylene, in the absence of plasticizer, wherein there are regions of ethylene vinyl alcohol copolymer having an average diameter of less than 500 angstroms in the polyamide, said compositions having been processed at a temperature of from about 225° C. to 252° C. and being substantially free from crosslinking.

Claim 24

A film having a thickness of from about 0.4 mils to about 20 mils made from a heterogeneous melt blended composition consisting essentially of: a polyamide; and from 10 to 90% by weight of an ethylene vinyl alcohol copolymer having 20 to 45 mol percent ethylene, in the absence of plasticizer, wherein there are regions of ethylene vinyl alcohol copolymer having an average diameter of less than 500 angstroms in the polyamide, said compositions having been processed at a temperature of from about 225° C. to 252° C. and being substantially free from crosslinking.

Claim 25

A heterogeneous melt blended composition consisting essentially of a polyamide; and from 10 to 90 percent by weight of an ethylene vinyl alcohol copolymer having 20 to 45 mol percent ethylene, in the absence of plasticizer, said composition having been processed at a temperature of from about 225° C. to 252° C. and being substantially free from crosslinking.

Claim 26

A heterogeneous melt blended composition consisting essentially of a polyamide; and from 10 to 90 percent by weight of an ethylene vinyl alcohol copolymer having 20 to 45 mol percent ethylene, in the absence of plasticizer, said composition having been processed at a temperature of from about 225° C. to 252° C. and being substantially free from crosslinking.

Claim 27

A heterogeneous melt blended composition consisting essentially of polyepsilocaprolactam; and from 10 to 90 percent by weight of the polyepsiloncaprolactam of an ethylene vinyl alcohol having 20 to 45 mol percent ethylene, in the absence of plasticizer, said composition having been processed at a temperature of from about 225° C. to 252° C. and being substantially free from crosslinking.

Claim 28

A heterogeneous melt blended composition consisting essentially of polyepsilocaprolactam; and from 10 to 90 percent by weight of the polyepsiloncaprolactam of an ethylene vinyl alcohol having 20 to 45 mol percent ethylene, in the absence of plasticizer, said composition having been processed at a temperature of from about 225° C. to 252° C. and being substantially free from crosslinking.

Claim 29

The composition as recited in claim 21 wherein there is from 10 to 50 percent by weight of the polyepsiloncaprolactam of the ethylene vinyl alcohol copolymer.

Claim 30

The composition as recited in claim 22 wherein there is from 10 to 30 percent by weight of the polyepsiloncaprolactam of the ethylene vinyl alcohol copolymer.

Claim 31

The composition as recited in claim 23 formed into a film.

Claim 32

The composition as recited in claim 21 wherein polyepsiloncaprolactam and ethylene vinyl alcohol are blended to have ethylene vinyl alcohol copolymer regions of less than 500 angstroms.

Claim 33

The composition of as recited in claim 25 wherein the ethylene vinyl alcohol regions are predominantly between 20 and 100 angstroms.

Claim 34

The composition as recited in claim 21 wherein there is from 30 to 65 percent by weight of the ethylene vinyl alcohol copolymer.

Claim 35

The composition as recited in claim 21 wherein there is from about 10 to about 20 percent by weight of the ethylene vinyl alcohol copolymer.

Claim 36

The composition as recited in claim 21 wherein the ethylene vinyl alcohol copolymer contains 20 to 45 mol percent ethylene.

Claim 39

The method as recited in claim 30 wherein the composition is blended until the ethylene vinyl alcohol regions in the blend are from 20 to 100 angstroms.

Claim 40

The composition as recited in claim 20 wherein the composition was processed at a temperature of about 225° C. to 240° C.

Claim 41

The composition as recited in claim 21 wherein the composition was processed at a temperature of about 225° C. to 240° C.

Claim 42

In a method for the production of a film having good strength, toughness and oxygen barrier properties, the steps comprising: a. forming a blend of about 90 to 10 weight percent of a nylon resin, conversely about 10 to 90 weight percent of an ethylene vinyl alcohol copolymer having a molecular weight of about 15,000 to 30,000 and a melting point temperature of about 325° to 375° Fahrenheit, and up to about 25 percent, based upon the weight of said nylon resin, of a plasticizer therefor, the processing temperature of said blend being at a value approximating that of said copolymer and below the temperature at which any substantial amount of degradation would occur therein under appropriate conditions for extrusion; b. heating said blend to said processing temperature; c. forcing said blend through an extrusion die to produce a film of said blend; d. adjusting the temperature of said film to permit effective molecular orientation therein; e. stretching said film at about said temperature to effect at least uniaxial molecular orientation therein; and f. cooling said film to obtain a product of relatively thin gauge having such desirable levels of strength, toughness and oxygen barrier capability.

Claim 43

In a method for the production of a film having good strength, toughness and oxygen barrier properties, the steps comprising: a. forming a blend of about 90 to 10 weight percent of a nylon resin, conversely about 10 to 90 weight percent of an ethylene vinyl alcohol copolymer having a molecular weight of about 15,000 to 30,000 and a melting point temperature of about 325° to 375° Fahrenheit, and up to about 25 percent, based upon the weight of said nylon resin, of a plasticizer therefor, the processing temperature of said blend being at a value approximating that of said copolymer and below the temperature at which any substantial amount of degradation would occur therein under appropriate conditions for extrusion; b. heating said blend to said processing temperature; c. forcing said blend through an extrusion die to produce a film of said blend; d. adjusting the temperature of said film to permit effective molecular orientation therein; e. stretching said film at about said temperature to effect at least uniaxial molecular orientation therein; and f. cooling said film to obtain a product of relatively thin gauge having such desirable levels of strength, toughness and oxygen barrier capability.

Claim 44

The method of claim 34 wherein said processing temperature is in excess of about 400° Fahrenheit.

Claim 45

The method of claim 35 wherein said processing temperature is about 430° to 480° Fahrenheit.

Claim 46

The method of claim 34 wherein said nylon resin has a molecular weight of about 20,000 to 30,000 and a melting point temperature of about 415° to 440° Fahrenheit, and wherein said plasticizer is present in an amount of at least 2 percent, based on said nylon resin, and is selected from the group consisting of fatty acid amides, aromatic sulfonamides, polyamides and copolyamides having a molecular weight of about 5,000 to 25,000 and a melting point temperature below about 400° Fahrenheit, said plasticizer being effective to lower the processing temperature of said nylon resin to approximately that of said copolymer.

Claim 47

The method of claim 37 wherein said plasticizer is selected from the class consisting of lauramide, o,ptoluenesulfonamide, N-ethyl-o,p-toluenesulfonamide and polyamides of 7,000 to 10,000 molecular weight.

Claim 48

The method of claim 37 including the additional step of compounding said nylon resin and said plasticizer prior to said step of forming said blend.

Claim 49

The method of claim 34 wherein at least a portion of said nylon resin in said blend is an ingredient selected from the group consisting of nylon random copolymers, nylon block copolymers, nylon alloys and nylon homopolymers, said ingredient having a melting point temperature below about 400° Fahrenheit.

Claim 50

The method of claim 40 wherein said group comprises nylon 12, nylon 6,12, nylon 6,36, nylon 6,66, nylon 6/polyolefin alloys and nylon 12/polyether or polyolefin block copolymers.

Claim 51

The method of claim 34 including the additional step of introducing into said extruder a second resin having a composition different from that of said blend, said second resin being combined with said blend in said die to produce a laminar structure of plural layers, and said structure being extruded from said die as a multilayer film inc.luding one layer comprised of said blend and a second layer comprised of said resin.

Claim 52

The method of claim 42 wherein said resin is selected from the group consisting of ethylene/organic acid ester copolymers, polyolefins, film-forming nylons, ionomer resins, partially hydrolyzed ethylene vinyl acetate copolymer adhesives, and anhydride modified polyolefin adhesives.

Claim 53

The method of claim 34 wherein said film is mechanically drawn in a first direction at a ratio greater than about 2:1 to effect molecular orientation therein.

Claim 54

The method of claim 44 wherein said draw ratio is at least about 4:1.

Claim 55

The method of claim 44 wherein said film is stretched in a direction substantially transverse to said first direction at a ratio greater than about 2:1, thereby producing biaxial molecular orientation in said film.

Claim 56

The method of claim 43 wherein said film is a single ply structure, and is produced by casting the extrudate from said step "c" upon a chill roll.

Claim 57

The method of claim 46 wherein said film is a tubular structure, and is produced by a blown film technique in said step "c".

Claim 58

The method of claim 48 wherein said tubular structure is stretched in said transverse direction by internal fluid pressure.

Claim 59

The method of claim 49 wherein said draw and stretch ratios are each at least about 3:1.

Claim 60

The method of claim 50 wherein at least one of said ratios is in excess of about 4:1.