HK1118762A

HK1118762A - Multiple layer film of a new non-pvc material

Info

Publication number: HK1118762A
Application number: HK08112692.8A
Authority: HK
Inventors: 吴力弓; 尚学文; 林忠建; 丁原邦; 杨大华; 克雷格．桑福德
Original assignee: 巴克斯特国际公司
Priority date: 2000-03-16
Filing date: 2004-11-22
Publication date: 2009-02-20

Description

Multilayer film of non-polyvinyl chloride material

The application is a divisional application of international application date 3 and 16 in 2001, international application number PCT/US2001/008598 in China at 9 and 13 in 2002, application number 01806492.2 and invention name of 'novel non-polyvinyl chloride material multilayer film'.

Technical Field

This invention relates generally to polymer blends for making films, and more particularly to films having low distortion, non-adhesive upon steam sterilization, which are heat sealable and suitable for forming flexible medical containers.

Background

In the medical field, the materials used to prepare the containers must have a unique combination of properties, as beneficial agents are often collected, processed and stored in the container, delivered, and ultimately delivered by injection through a catheter to a patient for therapeutic effect. For example, visual inspection of solution particulate contamination requires an optically clear container. In order to inject a solution by collapsing the container walls without introducing air into the container, the material forming the container walls must be sufficiently flexible. The material must be able to maintain its flexibility and rigidity over a wide temperature range. The material must be able to maintain its flexibility and rigidity at low temperatures to reduce degradation of the drug, since some solutions, such as pre-mixed drug solutions, are stored and transported in containers at temperatures from-25 ℃ to-30 ℃. The material must also function at high temperatures and resist deformation to withstand the heat of steam sterilization; steam sterilization is a process that must be performed before the containers of numerous medical fluids and nutritional products are shipped. The sterilization process typically involves exposing the container to steam at a temperature of 121 c and under elevated pressure.

To facilitate the formation of useful articles, the material is preferably sealable when heat sealing techniques are used. The material must therefore retain sufficient thermoplasticity to melt upon heating.

Another requirement is to reduce the environmental impact of articles made from this material when they are disposed of after they have achieved their intended utility. For articles that are disposed of in a landfill, it is desirable to reduce or avoid the incorporation of low molecular weight leachable components in the preparation of the articles. Further advantages can be achieved by using materials that allow for the hot thermoforming of scrap in production.

For those containers that are destroyed by incineration to reduce biohazards, it is desirable to use materials that reduce or eliminate the formation of environmentally undesirable and corrosive inorganic acids.

Such materials preferably contain no or low levels of low molecular weight additives such as plasticizers, stabilizers and the like which are capable of being released into pharmaceutical or biological fluids.

Flexible polyvinyl chloride (PVC), which is the material of choice for pharmaceutical packaging applications, is commonly used because it meets a variety of functional requirements. PVC shows significant advantages as one of the lowest cost materials for making devices that meet the above requirements. However, PVC also has some disadvantages in the market place. These disadvantages generally include incompatibility of PVC compounds with certain drugs, concerns about chlorine content and its impact on the environment, and increased negative market recognition of PVC. Therefore, many materials have been designed to replace PVC. However, many alternative materials are too expensive to implement and still do not meet all of the above requirements.

Polyolefins and polyolefin blends have been developed that meet many of the requirements for medical containers and catheters without the drawbacks of PVC. Polyolefins are generally compatible with medical applications because of their low extractability to fluids. Many polyolefins are environmentally friendly in that they do not produce harmful degradants upon incineration and are suitable for thermoplastic recycling. Many polyolefins are low cost materials and offer an economical alternative to PVC. However, there are many obstacles to overcome to the superior attributes of replacing all PVC with polyolefins.

For example, problems have been encountered in the use of such polyolefins in the preparation of medical catheters. Such catheters have been found to have poor surface characteristics such that the tubing is easily cut, shredded or scored when gripped with a slip clamp. Moreover, such polyolefins having better modulus properties, such as ultra low density polyethylene, have melting point temperatures lower than those achieved in autoclave processing.

It is known that crosslinking by chemical agents or high energy ionizing radiation can improve the heat resistance of a polymer matrix. Chemical crosslinking is a covalent bond between individual polymer chains that greatly retards the tendency of the polymer to deform and flow at high temperatures, even above the melting point of the polymer. For example, U.S. patent No.4,465,487 to Terumo discloses that vapor autoclave medical containers can be prepared by irradiating ethylene vinyl acetate copolymers using a high energy electron beam (2Mev) at a dose of 50kGy to 100kGy to achieve gel contents of 50% to 85%. The' 487 patent discloses that if the EVA sidewall of the container is irradiated to achieve a gel content of about 50% or more prior to sealing, the EVA sidewall peels easily. (column 4, lines 20-30). Thus, the' 487 patent discloses irradiating the sidewall of the container after the container is sealed as a pouch and only one port is left unsealed.

Similarly, U.S. patent No.4,453,940 discloses making medical containers from EVA and other materials. The' 940 patent also discloses a step of increasing the autoclave resistance of EVA by cross-linking the material with a high energy electron beam. The' 940 patent suggests that if the degree of crosslinking exceeds 50%, it is not possible to reuse the heat sealing process. (column 4, lines 27-35).

U.S. patent No.4,401,536 discloses a crosslinked semi-rigid container composed of a blend of polypropylene and EVA or EEA. This patent does not disclose the use of ethylene alpha-olefins and polypropylene. It is also disclosed that irradiation prior to article formation can result in articles having poor heat sealability. (column 4, lines 25-28).

U.S. patent nos. 4,892,604 and 5,066,290, assigned to the present assignee, disclose a medical container having a coextruded high density polyethylene outer layer (skin layer) and a core layer of ethylene vinyl acetate copolymer having a vinyl acetate content of about 18%. After the container is prepared by conventional radio frequency heat sealing techniques, the assembly is subjected to about 100kGy of ionizing radiation from a high energy electron beam accelerator of about 5 Mev. The high density polyethylene layer acts as a barrier to the transmission of moisture and air to maintain the sterile fluid content at a relatively constant concentration, as required by various pharmacopoeias throughout the world. There are, however, some serious drawbacks in the construction of this material: 1) to construct a container from such a material, the container must be prepared prior to the crosslinking process because the crosslinked EVA layer is difficult or even impossible to seal (which results in inefficiencies in the manufacturing process); and 2) the radiation dose required for adequate crosslinking also releases large amounts of acetic acid as a radiation byproduct. Since high density polyethylene is an obstacle to gas transport, the trapped acetic acid makes the fluid inside the package acidic-a very bad result.

U.S. patent No.4,643,926 issued to w.r.grace discloses the preparation of containers for medical liquids from a multilayer material, in a particular embodiment wherein the layers requiring heat sealing are made of a material based on polypropylene. It is well known that heat-sealable layers can remain thermoplastic and can be heat-sealed to similar surfaces due to chain scission of polypropylene under light. Thus, the entire multilayer film can be heat sealed and can continue to be used in autoclaving. However, the complexity of the multilayer construction and the potential need to clean and dope the film with an acid scavenger to remove the acidic byproducts generated by irradiating EVA makes this process quite complex and costly. Moreover, because such films are constructed of several dissimilar materials, edge trimming and other film scrap recycling processes are difficult and impractical without compromising optical and mechanical properties.

U.S. Pat. No.5,055,328 discloses a multilayer specifically crosslinked film wherein the heat seal layer contains added antioxidants to retard crosslinking and to promote heat sealing after crosslinking. Similarly, canadian patent 1,125,229 discloses another specific crosslinked multilayer film whose outer layer contains a crosslinking promoter. However, these structures are all multilayer structures and do not address the problem of self-adhesion during autoclave processing.

U.S. patent No.4,724,176 to Sun discloses a multilayer, oriented, heat-shrinkable container having a radiation-crosslinked outer layer and a non-crosslinked inner seal layer obtained by controlling the irradiation process. The inner and outer layers may be EVA copolymers. Such a vessel may shrink when heated and therefore may not be suitable as a vessel that must retain substantially its full volume after autoclaving.

The main object of the present invention is to provide polymerizable materials which are generally superior to other materials known to us, i.e. those which are well known in the art or which have been used commercially or marketed. The properties of such materials include flexibility, optical clarity for visual inspection, and effective heat resistance to withstand steam sterilization processes at temperatures up to 121 ℃ without significant distortion or self-adhesion. Such materials should also be non-oriented, non-cohesive and capable of being sealed using heat sealing techniques. Such materials should also be substantially free of low molecular weight leachable additives and be safely incinerated without the formation of substantial amounts of corrosive inorganic acids. In addition, such materials should be a low cost alternative to the various PVC materials currently used in medical devices.

U.S. patent No.5,879,768 discloses a pouch for packaging flowable materials prepared from a material containing a sealing layer of a polymerizable composition comprising: (A)10 to 100% of a blend of (1) and (2), wherein (1) refers to from 5 to 95% of at least one homogeneously branched linear ethylene/α -olefin interpolymer, and (2)5 to 95% of a high pressure low density polyethylene having a density of from 0.916 to 0.930 g/cc; and (B) 0-90% of a polymer selected from the group consisting of ultra low density polyethylene, linear low density polyethylene, high pressure low density polyethylene, ethylene vinyl acetate copolymer, and homogeneously branched linear ethylene polymers. The' 768 patent does not disclose irradiation of such blends, nor does it disclose blending such homogeneously branched, generally linear ethylene/α -olefin copolymers with polypropylene.

When more than one polymer is mixed to form a blended composition, it is difficult to achieve all of the above objectives simultaneously. For example, many blends produce significant light scattering; therefore, they cannot satisfy the requirement of optical transparency. The intensity of light scattering (measured by haze) depends on the particle size of the components in the micron range, and the proximity of the refractive indices of these components. As a general rule, it is difficult to select a composition that can be satisfactorily processed into very small particle sizes with a minimum difference in refractive index. The present invention addresses these and other issues.

Summary of The Invention

The present invention provides a non-polyvinyl chloride, non-oriented, multilayer film. The film comprises at least a first layer and a second layer bonded to each other. The first layer is a blend of the first component and the second component. The first component is selected from the following: (1) ethylene and α -olefin interpolymers having a density less than 0.915g/cc, (2) ethylene and lower alkyl acrylate interpolymers, (3) ethylene and lower alkyl substituted alkyl acrylate interpolymers, and (4) ionic polymers, commonly referred to as ionomers. The second component is selected from one or more of the following: (1) propylene-containing polymers, (2) butene-containing polymers, (3) polymethylpentene-containing polymers, (4) cyclic olefin-containing polymers and (5) bridged polycyclic hydrocarbon-containing polymers. The proportion of the second component in the blend is from about 35% to about 1% by weight.

The film has an elastic modulus of less than about 60,000psi as measured by ASTM D882, an internal haze of less than about 25% as measured by ASTM D1003, a self-adhesion of greater than about 2 as defined below, little or no adhesion to an over bag (over pouch) material, and a sample creep of less than or equal to 150% at 120 ℃ and under a 27psi load, and is heat sealable to form a container having a seal wherein the seal remains intact when the container with liquid is autoclaved at 121 ℃ for one hour.

Specifically, the present invention relates to the following.

1. A multilayer film, the film comprising:

a first outer layer of a blend of a first component and a second component, the first component being selected from the following: (1) ethylene and alpha-olefin copolymers having a density of less than 0.915g/cc, (2) with acrylic acid C₁-C₁₇Alkyl ester copolymerized ethylene, (3) and C₁-C₁₇Alkyl substituted alkyl acrylate copolymerized ethylene and (4) an ionomer, the proportion of the first component in the blend being from about 99 to about 55 weight percent, and the proportion of the second component in the blend being from about 45 to about 1 weight percent and selected from the group consisting of: (1) propylene-containing polymers, (2) polybutylene polymers, (3) polymethylpentene polymers, (4) cyclic olefin-containing polymers and (5) bridged polycyclic hydrocarbon-containing polymers;

the second layer is selected from the group consisting of propylene homopolymers, propylene copolymers, ethylene homopolymers, ethylene copolymers, polyesters, copolyesters, polyamides, and copolyamides; and the number of the first and second electrodes,

the film is non-oriented and has an elastic modulus of less than 60,000psi as measured by ASTM D882, an internal haze of less than about 25% as measured by ASTM D1003, an internal bond of greater than 2 such that the film can be formed into a roll and autoclaved and can be unwound after autoclaving, and a sample creep of less than or equal to 150% at 120 ℃ under 27psi loading for a film having a thickness of about 5 mils to about 15 mils, the film being heat sealable into a container having a seal which remains intact when the container is autoclaved at 121 ℃ for one hour.

2. The film of above 1, wherein the propylene containing polymer is selected from the group consisting of homopolymers of polypropylene, random copolymers of propylene, block copolymers of propylene, random terpolymers of propylene, and block terpolymers of propylene, wherein the copolymers and terpolymers of propylene have comonomers selected from α -olefins having from 2 to about 17 carbon atoms.

3. The film of the above 2, wherein the second component is a copolymer of propylene and ethylene and the content of ethylene in the copolymer is 1 to 6% by weight.

4. The film of above 2, wherein the second component is a blend of a first propylene containing polymer and a second propylene containing polymer.

5. The film of 4 above, wherein the first propylene containing polymer has a first melt flow rate and the second propylene containing polymer has a second melt flow rate, the first melt flow rate being about 3 times the second melt flow rate.

6. The film of 4 above, wherein the first propylene containing polymer has a first melt flow rate and the second propylene containing polymer has a second melt flow rate, the first melt flow rate being about 5 times the second melt flow rate.

7. The film of above 4, wherein the first propylene containing polymer has a first melting point temperature and the second propylene containing polymer has a second melting point temperature, the first melting point temperature being at least 5 ℃ higher than the second melting point temperature.

8. The film of above 4, wherein the first propylene containing polymer has a first melting point temperature and the second propylene containing polymer has a second melting point temperature, the first melting point temperature being at least 10 ℃ higher than the second melting point temperature.

9. The film of 4 above, wherein the first propylene containing polymer has a first melt flow rate and the second propylene containing polymer has a second melt flow rate, the first melt flow rate being different from the second melt flow rate.

10. The film of above 4, wherein the first propylene containing polymer has a first melting point temperature and the second propylene containing polymer has a second melting point temperature, the first melting point temperature being different from the second melting point temperature.

11. The film of above 1, wherein the cyclic olefin has from 5 to about 10 carbon atoms in the ring.

12. The film of above 11, wherein the cyclic olefin is selected from the group consisting of cyclopentene, cyclopentadiene, cyclohexene, cyclohexadiene, cycloheptene, cycloheptadiene, cyclooctene, and cyclooctadiene.

13. The film of the above 12, wherein the cycloolefin has a molecular weight selected from the group consisting of C₁-C₁₇Alkyl and acrylate derivatives.

14. The membrane of above 1 wherein the bridged polycyclic hydrocarbon has at least 7 carbon atoms.

15. The membrane of 14 above, wherein the bridged polycyclic hydrocarbon is selected from the group consisting of polycyclic hydrocarbons having at least 7 carbon atoms.

16. The film of above 1, wherein the α -olefin has 3 to 17 carbon atoms.

17. The film of above 1, wherein the α -olefin has 4 to 8 carbon atoms.

18. The membrane of the above 17, wherein the copolymer of ethylene and α -olefin is obtained by a single site catalyst.

19. The film of above 1, wherein the blend is electron beam irradiated at a dose of about 20kGy to about 200 kGy.

20. The film of above 1, wherein the second layer is selected from the group consisting of a skin layer, a radio frequency sensitive layer, a water vapor barrier layer, a gas barrier layer, a chip layer, a sealant layer, and a core layer.

21. A multilayer film made by a coextrusion process, the film comprising:

a first outer layer of a blend of a first component and a second component, the first component selected from the group consisting of: (1) ethylene and alpha-olefin copolymers having a density of less than 0.915g/cc, (2) with acrylic acid C₁-C₁₇Alkyl ester copolymerized ethylene, (3) and C₁-C₁₇Alkyl substituted alkyl acrylate copolymerized ethylene and (4) an ionomer, the first component being present in the blend in a proportion of about 99% to about 55% by weight, the second component being present in the blend in a proportion of about 45% to about 1% by weight and selected from the group consisting of: (1) propylene-containing polymers, (2) polybutylene polymers, (3) polymethylpentene polymers, (4) cyclic olefin-containing polymers and (5) bridged polycyclic hydrocarbon-containing polymers;

wherein said film is non-oriented and is subjected to electron beam irradiation at a dose of about 20kGy to about 200 kGy.

22. The film of above 21, wherein the film has an elastic modulus of less than 60,000psi as measured by ASTM D882, an internal haze of less than 25% as measured by ASTM D1003, an internal bond of greater than 2 such that the film can be formed into a roll and autoclaved and can be unrolled after autoclaving, a sample creep of less than or equal to 150% at 120 ℃ under a 27psi load for a film having a thickness of from about 5 mils to about 15 mils, and the film can be heat sealed into a container having seals that remain intact when the container is autoclaved at 121 ℃ for one hour.

23. The film of above 21, wherein the film has an oxygen partial pressure less than ambient conditions when the film is subjected to electron beam radiation.

24. The film of above 21, wherein the propylene containing polymer is selected from the group consisting of homopolymers of polypropylene, random copolymers of propylene, block copolymers of propylene, random terpolymers of propylene, and block terpolymers of propylene, wherein the copolymers and terpolymers of propylene have comonomers selected from α -olefins having from 2 to about 17 carbon atoms.

25. The film of the above 21, wherein the second component is a copolymer of propylene and ethylene and the content of ethylene in the copolymer is 1 to 6% by weight.

26. The film of above 21, wherein the second component is a blend of a first propylene containing polymer and a second propylene containing polymer.

27. The film of 26 above, wherein the first propylene containing polymer has a first melt flow rate and the second propylene containing polymer has a second melt flow rate, the first melt flow rate being about 3 times the second melt flow rate.

28. The film of 26 above, wherein the first propylene containing polymer has a first melt flow rate and the second propylene containing polymer has a second melt flow rate, the first melt flow rate being about 5 times the second melt flow rate.

29. The film of 26 above, wherein the first propylene containing polymer has a first melting point temperature and the second propylene containing polymer has a second melting point temperature, the first melting point temperature being at least 5 ℃ higher than the second melting point temperature.

30. The film of 26 above, wherein the first propylene containing polymer has a first melting point temperature and the second propylene containing polymer has a second melting point temperature, the first melting point temperature being at least 10 ℃ higher than the second melting point temperature.

31. The film of 26 above, wherein the first propylene containing polymer has a first melt flow rate and the second propylene containing polymer has a second melt flow rate, the first melt flow rate being different from the second melt flow rate.

32. The film of 26 above, wherein the first propylene containing polymer has a first melting point temperature and the second propylene containing polymer has a second melting point temperature, the first melting point temperature being different from the second melting point temperature.

33. The film of above 21, wherein the cyclic olefin has from 5 to about 10 carbon atoms in the ring.

34. The film of 33 wherein the cyclic olefin is selected from the group consisting of cyclopentene, cyclopentadiene, cyclohexene, cyclohexadiene, cycloheptene, cycloheptadiene, cyclooctene, and cyclooctadiene.

35. The film of the above 34, wherein the cycloolefin has a molecular weight selected from the group consisting of C₁-C₁₇Alkyl and acrylate derivatives.

36. The membrane of 21 above, wherein the bridged polycyclic hydrocarbon has at least 7 carbon atoms.

37. The membrane of 36 above, wherein the bridged polycyclic hydrocarbon is selected from the group consisting of polycyclic hydrocarbons having at least 7 carbon atoms.

38. The film of above 21, wherein the α -olefin has 3 to 17 carbon atoms.

39. The film of above 38, wherein the copolymer of ethylene and α -olefin is obtained by a single site catalyst.

40. The film of above 21, wherein the α -olefin has 4 to 8 carbon atoms.

41. The film of above 21, wherein the second layer is selected from the group consisting of a skin layer, a radio frequency sensitive layer, a water vapor barrier layer, a gas barrier layer, a debris layer, a sealant layer, and a core layer.

42. A multilayer film, the film comprising:

a first outer layer of a blend of a first component and a second component, the first component being an ethylene and α -olefin copolymer having a density less than 0.915g/cc, the first component being present in the blend in a proportion of about 99 to about 55 wt%, and the second component being present in the blend in a proportion of about 45 to about 1 wt% and selected from the group consisting of: (1) propylene-containing polymers, (2) polybutylene polymers, (3) polymethylpentene polymers, (4) cyclic olefin-containing polymers and (5) bridged polycyclic hydrocarbon-containing polymers;

a second layer adhered to the first layer; and the second layer is selected from the group consisting of propylene homopolymers, propylene copolymers, ethylene homopolymers, ethylene copolymers, polyesters, copolyesters, polyamides and copolyamides, and

the film is non-oriented and has an elastic modulus of less than 60,000psi as measured by ASTM D882, an internal haze of less than 25% as measured by ASTM D1003, an internal bond of greater than 2 such that the film can be formed into a roll and autoclaved and can be unwound after autoclaving, and a sample creep of less than or equal to 150% at 120 ℃ under 27psi loading for a film having a thickness of from about 5 mils to about 15 mils, the film being heat sealable into a container having a seal which remains intact when the container is autoclaved at 121 ℃ for one hour.

43. The film of 42, wherein the copolymer of ethylene and α -olefin is obtained by a single site catalyst.

44. A multilayer film, the film comprising:

a first outer layer of a blend of ethylene and an α -olefin copolymer and a second component, the ethylene and α -olefin copolymer being obtained by a single site catalyst and having a density of less than 0.915g/cc and being present in the blend in a proportion of from about 99% to about 55% by weight, the second component being present in the blend in a proportion of from about 45% to about 1% by weight and selected from the group consisting of: (1) propylene-containing polymers, (2) polybutylene polymers, (3) polymethylpentene polymers, (4) cyclic olefin-containing polymers and (5) bridged polycyclic hydrocarbon-containing polymers;

45. A multilayer film, the film comprising:

a first layer of a blend of a first component and a second component, the first component selected from the group consisting of: (1) ethylene and alpha-olefin copolymers having a density of less than 0.915g/cc, (2) with acrylic acid C₁-C₁₇Alkyl ester copolymerized ethylene, (3) and C₁-C₁₇Alkyl substituted alkyl acrylate copolymerized ethylene and (4) an ionomer, the first component being present in the blend in a proportion of about 99% to about 55% by weight and the second component being present in the blend in a proportion of about 45% to about 1% by weight and consisting of a blend of a first propylene containing polymer and a second propylene containing polymer;

the film has an elastic modulus of less than 60,000psi as measured by ASTM D882, an internal haze of less than 25% as measured by ASTM D1003, an internal bond of greater than 2 such that the film can be formed into a roll and autoclaved and can be unwound after autoclaving, and a sample creep of less than or equal to 150% at 120 ℃ under 27psi loading for a film having a thickness of about 5 mils to about 15 mils, the film being heat sealable into a container having a seal which remains intact when the container is autoclaved at 121 ℃ for one hour.

46. The film of 45 above, wherein the first propylene containing polymer has a first melt flow rate and the second propylene containing polymer has a second melt flow rate, the first melt flow rate being about 3 times the second melt flow rate.

47. The film of 45 above, wherein the first propylene containing polymer has a first melt flow rate and the second propylene containing polymer has a second melt flow rate, the first melt flow rate being about 5 times the second melt flow rate.

48. The film of 45 above, wherein the first propylene containing polymer has a first melting point temperature and the second propylene containing polymer has a second melting point temperature, the first melting point temperature being at least 5 ℃ higher than the second melting point temperature.

49. The film of 45 above, wherein the first propylene containing polymer has a first melting point temperature and the second propylene containing polymer has a second melting point temperature, the first melting point temperature being at least 10 ℃ higher than the second melting point temperature.

50. The film of 45 above, wherein the first propylene containing polymer has a first melt flow rate and the second propylene containing polymer has a second melt flow rate, the first melt flow rate being different from the second melt flow rate.

51. The film of 45 above, wherein the first propylene containing polymer has a first melting point temperature and the second propylene containing polymer has a second melting point temperature, the first melting point temperature being different from the second melting point temperature.

52. A multilayer film, the film comprising:

a first outer layer of a blend of a first component and a second component, the first component being selected from the following: (1) ethylene and alpha-olefin copolymers having a density of less than 0.915g/cc, (2) with acrylic acid C₁-C₁₇Alkyl ester copolymerized ethylene, (3) and C₁-C₁₇Alkyl substituted alkyl acrylate copolymerized ethylene and (4) an ionomer, the first component being present in the blend in a proportion of about 99% to about 55% by weight and the second component being present in the blend in a proportion of about 45% to about 1% by weight and consisting of a blend of a first propylene containing polymer and a second propylene containing polymer;

53. The film of 52 above, wherein the first propylene containing polymer has a first melt flow rate and the second propylene containing polymer has a second melt flow rate, the first melt flow rate being about 3 times the second melt flow rate.

54. The film of 52 above, wherein the first propylene containing polymer has a first melt flow rate and the second propylene containing polymer has a second melt flow rate, the first melt flow rate being about 5 times the second melt flow rate.

55. The film of 52 above, wherein the first propylene containing polymer has a first melting point temperature and the second propylene containing polymer has a second melting point temperature, the first melting point temperature being at least about 5 ℃ higher than the second melting point temperature.

56. The film of 52 above, wherein the first propylene containing polymer has a first melting point temperature and the second propylene containing polymer has a second melting point temperature, the first melting point temperature being at least about 10 ℃ higher than the second melting point temperature.

57. The film of above 46, wherein the first propylene containing polymer has a first melt flow rate and the second propylene containing polymer has a second melt flow rate, the first melt flow rate being different from the second melt flow rate.

58. The film of above 46, wherein the first propylene containing polymer has a first melting point temperature and the second propylene containing polymer has a second melting point temperature, the first melting point temperature being different from the second melting point temperature.

Brief description of the drawings

FIG. 1 is a cross-sectional view of a single layer film of the present invention;

FIG. 2 is a cross-sectional view of a multilayer film in accordance with the present invention;

FIG. 3 is a container made from the film of the present invention;

FIG. 4 is an intravenous fluid administration set;

FIG. 5 is a peritoneal dialysis container and catheter set; and

figure 6 is a dual chamber bag with peelable seals separating the chambers.

Detailed Description

The embodiments of the invention can take many different forms. It is to be understood that the disclosure of the preferred embodiments of the invention is to be considered as an exemplification of the principles of the invention and is not intended to limit the invention to the illustrated embodiments.

I. Polymer blend and monolayer film thereof

Fig. 1 is a single layer film 10 of the present invention. The monolayer film 10 is prepared from a polymer blend comprising a first component and a second component. The first component is selected from the group consisting of: (1) ethylene and α -olefin interpolymers having a density less than 0.915g/cc, (2) ethylene and lower alkyl acrylate interpolymers, (3) ethylene and lower alkyl substituted alkyl acrylate interpolymers, and (4) ionic polymers, commonly referred to as ionomers. The proportion of the first component in the blend is 99% to 55%, more preferably 60% to 85%, most preferably 65% to 80% by weight.

The second component is selected from the group consisting of: (1) propylene-containing polymers, (2) butene-containing polymers, (3) polymethylpentene-containing polymers, (4) cycloolefin-containing polymers and (5) bridged polycyclic hydrocarbon-containing polymers. The proportion of the second component in the blend is from about 45% to about 1%, more preferably from about 15% to about 40%, and most preferably from about 20% to about 35% by weight.

The film has an elastic modulus of less than about 60,000psi as measured by ASTM D882, an internal haze of less than about 25% as measured by ASTM D1003, a degree of self-adhesion of greater than about 2 (as defined below), little or no adhesion to the material of the super pouch, and a creep of less than or equal to 150% of the sample at 120 ℃ and under a load of about 27psi, and can be heat sealed into a container having a seal that remains intact after the container with liquid is treated in an autoclave at 121 ℃ for one hour.

As used herein, the term "interpolymer" includes random or block copolymers and terpolymers.

Suitable ethylene and α -olefin interpolymers preferably have a density, as measured by ASTM D-792, of less than 0.915g/cc, these polymers being commonly referred to as Very Low Density Polyethylene (VLDPE), Ultra Low Density Polyethylene (ULDPE) and the like. The alpha-olefin should contain 3 to 17 carbon atoms, more preferably 4 to 12 carbon atoms and most preferably 4 to 8 carbon atoms. In a preferred form of the invention, the copolymer of ethylene and alpha-olefin is obtained using a single site catalyst. Suitable single site catalyst systems are those disclosed in U.S. Pat. Nos.5,783,638 and 5,272,236, as well as other systems. Suitable ethylene and α -olefin copolymers include those sold by Dow chemical under the trade names AFFINITY, Dupont-Dow under the trade names ENGAGE and Exxon under the trade names EXACT and PLASTOMER.

The term "lower alkyl acrylate" refers to a comonomer having the formula shown in formula 1:

the R radical denotes an alkanyl radical having 1 to 17 carbon atoms. Thus, the term "lower alkyl acrylate" includes, but is not limited to, methyl acrylate, ethyl acrylate, butyl acrylate, and the like.

The term "alkyl substituted alkyl acrylate" refers to a comonomer having the formula shown in formula 2:

R₁and R₂Is an alkanyl radical having from 1 to 17 carbon atoms and can have the same or different number of carbon atoms. Thus, the term "alkyl substituted alkyl acrylate" includes, but is not limited to, methyl methacrylate, ethyl methacrylate, methyl ethacrylate, ethyl ethacrylate, butyl methacrylate, butyl ethacrylate, and the like.

Suitable propylene containing polymers include homopolymers of polypropylene, copolymers and terpolymers of propylene with one or more comonomers selected from alpha-olefins having from 2 to 17 carbon atoms. Suitable copolymers and terpolymers of polypropylene include random or block propylene and ethylene copolymers, or random or block propylene/ethylene/butene terpolymers. Suitable copolymers of propylene and α -olefins are sold by Montell under the trade names PRO FAX, PRO FAXULTRA and CATALLOY.

The present invention also contemplates the use of blends of propylene containing polymers as the second component of the blend. In a preferred form of the invention the blend comprises at least a first propylene containing polymer and a second propylene containing polymer. The first propylene containing polymer and the second propylene containing polymer may be selected from propylene homopolymers, copolymers and terpolymers. In a preferred embodiment of the invention the first propylene containing polymer differs from the second propylene containing polymer in at least one of two ways. The first difference is that the melt flow rate of the first propylene containing polymer is 3 times, particularly preferably 5 times, the melt flow rate of the second propylene containing polymer. The second difference is that the melting point of the first propylene containing polymer is preferably at least 5 c, more preferably at least 10 c higher than the melting point of the second propylene containing polymer. Melting points were measured according to astm d3417 (enthalpy of fusion and enthalpy of crystallization of polymers obtained by differential scanning calorimetry). The first propylene containing polymer may differ from the second propylene containing polymer in the first difference, the second difference, or both.

Suitable homopolymers and copolymers of cyclic olefins and bridged polycyclic hydrocarbons and blends thereof may be found in U.S. Pat. Nos.5,218,049, 5,854,349, 5,863,986, 5,795,945, 5,792,824; can also be found in european patents EP 0291,208, EP 0283,164, EP 0497,567, which are hereby incorporated by reference in their entirety and made a part hereof.

In a preferred form of the invention, suitable cyclic olefin monomers are monocyclic compounds having from 5 to 10 carbon atoms in the ring. The cyclic olefin can be selected from substituted and unsubstituted cyclopentene, cyclopentadiene, cyclohexene, cyclohexadiene, cycloheptene, cycloheptadiene, cyclooctene, cyclooctadiene. Suitable substituents include lower alkyl, acrylic acid derivatives and the like.

In a preferred form of the invention, suitable bridged polycyclic hydrocarbon monomers have two or more rings and particularly preferably contain at least 7 carbon atoms. The rings may be substituted or unsubstituted. Suitable substituents include lower alkyl, aryl, aralkyl, vinyl, allyloxy, (meth) acryloyloxy and the like. The bridged polycyclic hydrocarbon may be selected from the compounds disclosed in the above-incorporated patents and patent applications. Suitable polymers containing bridged polycyclic hydrocarbons are those sold by Ticona under the trade name TOPAS, by Nippon Zeon under the trade names ZEONEX and ZEONOR, by daikyogouu Seiko under the trade name CZ resin, and by Mitsui petrochemical under the trade name APEL.

In a preferred form of the invention, the film will have the following physical properties: (1) an elastic modulus of less than about 60,000psi as measured by ASTM D882, (2) an internal haze of less than about 25% as measured by ASTM D1003, (3) a self-adhesion of greater than about 2 as defined below, (4) no adhesion to the super-bag material, (5) a sample creep of less than or equal to 150% at 120 ℃ and a load of about 27psi, and (6) the film can be heat sealed into a container having a seal wherein the seal remains intact after one hour of autoclaving the container with the liquid at 121 ℃.

The film is also sufficiently flexible to produce a container for the flowable substance. The film has an elastic modulus of less than about 60,000psi, particularly preferably less than about 40,000psi, more preferably less than about 30,000psi and most preferably less than about 20,000psi as measured by ASTM D-882. When the container containing the flowable material is an intravenous container, the container is preferably collapsible or collapsed upon discharge of the liquid, such that the container has a modulus of elasticity as measured in accordance with ASTM D-882 of less than about 40,000psi, more preferably less than about 30,000psi, and even more preferably less than about 20,000 psi.

For the purposes of the present invention, self-adhesion is defined as the tendency of the film to adhere to itself during high pressure processing. Such performance may be determined by the following tests. The film was cut to 8 "x 2" with the length dimension coinciding with the machine direction. These strips were rolled into a tube approximately 0.5 "in diameter by 2" in length. The rolled film is held in place by pressing the film plies together from one end with a paper clip. These tubes were then placed in a 121 ℃ steam autoclave for about 30 minutes. The samples were allowed to cool for at least 1 hour. The film was then expanded. The resistance to unrolling and the relative damage to the film are listed in table 1:

TABLE 1

Results of level observation

1 the membrane cannot be unfolded without damaging the membrane.

2 the film was difficult to peel apart and had significant surface damage.

3 there is some resistance to peeling and little surface damage.

4 slight resistance with little or no surface damage upon peeling.

5 has no peel resistance and surface damage.

The level is determined by three or more persons and averaged as a result.

The adhesion of the super pocket material is determined by the following qualitative test. A one inch wide piece of film is sealed in a typical super pouch bag (medium or high density polyethylene). The over-bag was then placed in a laboratory autoclave at 252F and 24.5psig gauge pressure for one hour. After the high pressure treatment, the bag is cut open and the film is taken out. A no adhesion (N) rating is assigned if the film can be separated from the superpacket without leaving a mark of damage on the film surface. If the film separation produces a visible lesion, the rating (Y) indicates that the film is stuck in the super pocket. A scale (S) may also be given to indicate weak adhesion.

Creep performance was determined by clamping a film sheet having a thickness of about 5 mils (mils) to 15 mils at 120 c into a temperature controlled oven and loading it with a weight to generate a pressure of about 27 psi. After 40 minutes of loading, the membrane was removed and the dimensional change of the pre-marked one inch wide band was recorded.

The film may be sealed using standard heat sealing techniques. When a fluid container, such as the container shown in fig. 3, is made from a film that is sealed at the perimeter to define a central fluid chamber, a suitable seal may be formed. The vessel was filled with water and subjected to a standard autoclave sterilization process. Proper sealing can still be kept intact after the high-pressure reaction is finished.

The haze of the films of the present invention is less than about 25%, and very preferably less than about 15%, as measured by ASTM D1003. For the purposes of the present invention, internal haze is defined as the haze value measured when both sides of the membrane are wetted with isopropanol.

Processing of polymers and films

To prepare the films of the present invention, the raw materials were added to the extrusion funnel in a set weight mixing ratio using a gravimetric feeder. The material was extruded with an extrusion die to give a single layer film. The film is irradiated with a suitable energy source and sealed to form a fluid container. The blend may also be subjected to light prior to extrusion. The raw materials may also be pre-mixed prior to extrusion using a single screw, twin screw or other mixing methods familiar to those skilled in the art.

The preferred method of irradiating the film is by exposing it to an electron beam having an electron beam energy of about 150Kev to 10Mev, particularly preferably 200-300Kev, at a dose of about 20kGys to 200kGys, particularly preferably 60-150 kGys. Alternatively, the membrane may be crosslinked by methods well known to those skilled in the art. Crosslinking methods used in the industry include ionizing radiation (gamma, beta, ultraviolet, etc.) and chemical methods (peroxides and condensation polymerization).

To reduce or minimize oxidative degradation in and subsequent to electron beam irradiation, it is desirable to reduce the partial pressure of oxygen around the irradiated film. The partial pressure of oxygen is reduced using vacuum or using other gases such as high pressure nitrogen or other techniques for accomplishing this. In a preferred form of the invention, the oxygen content of the nitrogen stream is less than about 100ppm, with less than about 40ppm being particularly preferred.

Multilayer film

Fig. 2 is an embodiment of a multilayer film 20 that includes the monolayer layer 12 described above. In a preferred form of the invention, the monolayer should be a sealing layer. The multilayer film 20 may include any additional layer 14 or combination of additional layers selected from, for example, skin layers, radio frequency susceptible layers, water vapor barrier layers, gas barrier layers, particle layers, sealant layers, and core layers.

The addition of a skin layer may increase the frictional resistance of the film. The skin layers may be of olefinic materials such as homopolymers and copolymers of propylene and ethylene. The skin layer may also be a polyester, copolyester, polyamide or copolyamide. The term "copolyester" or the like refers to a polyester synthesized from more than one diol and diacid. The copolyester used herein may also be characterized as a copolymer of a polyether and polyethylene terephthalate. More preferably, the copolyester used herein may be characterized as a polymeric material derived from 1, 4-cyclohexanedimethanol, 1, 4-cyclohexanedicarboxylic acid and polytetramethylene glycol ether, or equivalents of any of the foregoing, as reactants.

Suitable water vapor barrier materials include, but are not limited to, HDPE, MDPE, and polyester (PET, PBT, PEN, etc.).

Suitable gas barrier materials are those which prevent the passage of oxygen, carbon dioxide or other gases. Suitable gas barrier materials include, but are not limited to, polyesters and polyamides.

The debris material generated prior to illumination may be doped into one or more layers.

Containers for flowable materials

Fig. 3 is a container of flowable material, specifically, an intravenous container 30. Fig. 4 shows an iv administration set 40 and fig. 5 shows a peritoneal dialysis set 50. The present invention also contemplates the use of the blends of the present invention to prepare medical catheters. The irradiation treatment at the time of tube production will be different from the treatment of the film due to the increased thickness of the tube and the circular structure of the tube, but the above irradiation energy range for the film is still effective for the treatment of the tube. "flowable material" refers to a material that is flowable under gravity. Flowable materials thus include both liquids and powders or granules and the like. The container 30 has side walls 32 that are sequentially positioned and sealed along a perimeter to define a chamber 34 for filling with a flowable material, such as a fluid or granular material. The longitudinal edges can be sealed for containers prepared solely by blow molding or blow extrusion. A single port tube 36 or a multiple port tube is used to fill or empty the container 30 of the substance. The sidewall and single port tube may be made from one of the single or multilayer films described above. Unexpectedly, medical articles made from the films or blends described above can be heat sealed even when the film has been irradiated with an electron beam.

Heat sealing can be accomplished by using standard heat sealing techniques known to those skilled in the art.

V. double-chamber peelable seal container

Fig. 6 is a dual-compartment container 70 comprising a first compartment 72 and a second compartment 74 separated by a peelable seal 76. The container sidewall 75 is made from one of the polymer blends, monolayer films, or multilayer films described above. Dual chamber containers have many applications such as storing two components separately for later mixing. The component may be a liquid or a powder. The peelable seal may be prepared by varying the sealing conditions in which the peelable seal 76 is torn by applying a force to the container sidewall 75. Typically, one of the chambers contains a liquid. By squeezing the container sidewall 75 of the chamber containing the liquid, the liquid material will flow towards the peelable seal 76 and the seal 76 will tear with sufficient pressure to allow the components stored in the different chambers to mix.

Although FIG. 6 shows only one peelable seal 76, multiple peelable seals may be provided to form multiple chambers. In addition, FIG. 6 shows that the peelable seal extends between the side edges. The peelable seal may also extend between the longitudinal edges or only around a region that does not intersect the fixed peripheral seal 79 to define a chamber.

The peelable seal 76 may be created at the same time as or before the peripheral sidewall is sealed or a permanent seal is made. Peelable seal 76 can be prepared by controlling the sealing conditions. The peelable seal layer is made by using lower temperatures and pressures than in preparing a fixed perimeter seal layer, or by shortening the sealing time for providing a fixed seal. The release properties can be further enhanced by local modification of the film surface properties (corona treatment (corona) or other suitable treatment methods).

The container may be sealed using ultrasonic welding techniques, conduction heat sealing techniques, and other sealing techniques known in the art.

V.i. examples

The blends in the table below were prepared as monolayer films by an extrusion process. The films were irradiated with electron beams at an acceleration voltage of 200 to 300Kev at doses as shown in the table:

formulation of	1	2	3	4	5	6	7	8	9	10
formulation of	1	2	3	4	5	6	7	8	9	10	DuPont/Dow Engage8003	100	95	90	80						70
Dow Affinity PL-1880					100	95	90	80	70		DuPont/Dow Engage8003	100	95	90	80						70
Dow Affinity PL-1880					100	95	90	80	70		Exxon PP3505GE1		5	10	20
Montell SA-861						5	10	20	30	20	Exxon PP3505GE1		5	10	20
Montell SA-861						5	10	20	30	20	Montell SG-982										10
Self-adhesion degree-100 kGy	1	2	3.7	4	1	NA	1	2	4	NA	Montell SG-982										10
Self-adhesion degree-100 kGy	1	2	3.7	4	1	NA	1	2	4	NA	150kGy	1	2	4.5	5	1	NA	1.3	2.3	3.3	NA
200kGy	1	3.3	4.7	5	1	1.7	2	2	4	NA	150kGy	1	2	4.5	5	1	NA	1.3	2.3	3.3	NA
200kGy	1	3.3	4.7	5	1	1.7	2	2	4	NA	Adhesion to Superpouch Material-100 kGy	Y	S	N	N	Y	NA	Y	S	N	NA
150kGy	Y	S	N	N	Y	NA	Y	N	N	NA	Adhesion to Superpouch Material-100 kGy	Y	S	N	N	Y	NA	Y	S	N	NA
150kGy	Y	S	N	N	Y	NA	Y	N	N	NA	200kGy	Y	S	N	N	Y	NA	Y	N	N	NA
Creep (%) 0kGy at 120 ℃	NA	NA	NA	NA	NA	NA	Melting	NA	550	NA	200kGy	Y	S	N	N	Y	NA	Y	N	N	NA
Creep (%) 0kGy at 120 ℃	NA	NA	NA	NA	NA	NA	Melting	NA	550	NA	100kGy	200	138	88	41	263	NA	216	98	28	NA
150kGy	63	38	31	18	43	NA	31	25	13	NA	100kGy	200	138	88	41	263	NA	216	98	28	NA
150kGy	63	38	31	18	43	NA	31	25	13	NA	200kGy	25	13	16	16	21	22	16	9	22	NA
Autoclave treatment of 100kGy	NA	NA	Y	Y	NA	NA	NA	Y	Y	Y	200kGy	25	13	16	16	21	22	16	9	22	NA
Autoclave treatment of 100kGy	NA	NA	Y	Y	NA	NA	NA	Y	Y	Y	150kGy	NA	NA	Y	Y	NA	NA	NA	Y	Y	Y
Internal haze (ASTM D1003)	1	1.2	1.6	2.8	2.7	2.7	3.5	4.3	4.8	2.2	150kGy	NA	NA	Y	Y	NA	NA	NA	Y	Y	Y
Internal haze (ASTM D1003)	1	1.2	1.6	2.8	2.7	2.7	3.5	4.3	4.8	2.2	Tensile modulus (psi, ASTM D882)	2860	3800	6650	16260	6110	NA	12830	19810	28820	21060

Dow Affinity PL 1880 is ULDPE with a density of 0.902 g/cc.

DuPont Dow Engage 8003 is ULDPE with a density of 0.885 g/cc.

Exxon PP305GE1 is a propylene homopolymer (MFR 440).

Montell SA-861 is a copolymer of propylene and ethylene (MFR 6.5).

Montell SA 982 is a copolymer of propylene and ethylene (MFR 100).

"NA" means unavailable.

Claims

1. A multilayer film, the film comprising:

a first outer layer of a blend of a first component and a second component, the first component being selected from the following: (1) ethylene and alpha-olefin copolymers having a density of less than 0.915g/cc, (2) with acrylic acid C₁-C₁₇Alkyl ester copolymerized ethylene, (3) and C₁-C₁₇Alkyl-substituted alkyl acrylate copolymerized ethylene and (4) ionomer, the first component being present in the blend in a proportion of 99 to 55% by weight and the second component being present in the blend in a proportion of 45 to E ℃, (4) the polymer containing ionic bonds1% by weight and is selected from the following polymers: (1) propylene-containing polymers, (2) polybutylene polymers, (3) polymethylpentene polymers, (4) cyclic olefin-containing polymers and (5) bridged polycyclic hydrocarbon-containing polymers;

the film is non-oriented and has an elastic modulus of less than 60,000psi as measured by ASTM D882, an internal haze of less than 25% as measured by ASTM D1003, an internal bond of greater than 2 such that the film can be formed into a roll and autoclaved and can be unwound after autoclaving, and a sample creep of less than or equal to 150% at 120 ℃ under 27psi loading for a film having a thickness of 5 mils to 15 mils, the film can be heat sealed into a container having a seal that remains intact when the container is autoclaved at 121 ℃ for one hour.

2. The film of claim 1 wherein the second component is a blend of a first propylene containing polymer and a second propylene containing polymer.

3. The film of claim 2, wherein the first propylene containing polymer has a first melt flow rate and the second propylene containing polymer has a second melt flow rate, the first melt flow rate being 3 times the second melt flow rate.

4. The film of claim 2, wherein the first propylene containing polymer has a first melt flow rate and the second propylene containing polymer has a second melt flow rate, the first melt flow rate being 5 times the second melt flow rate.

5. The film of claim 2, wherein the first propylene containing polymer has a first melting point temperature and the second propylene containing polymer has a second melting point temperature, the first melting point temperature being at least 5 ℃ higher than the second melting point temperature.

6. The film of claim 2, wherein the first propylene containing polymer has a first melting point temperature and the second propylene containing polymer has a second melting point temperature, the first melting point temperature being at least 10 ℃ higher than the second melting point temperature.

7. The film of claim 2, wherein the first propylene containing polymer has a first melt flow rate and the second propylene containing polymer has a second melt flow rate, the first melt flow rate being different from the second melt flow rate.

8. The film of claim 2, wherein the first propylene containing polymer has a first melting point temperature and the second propylene containing polymer has a second melting point temperature, the first melting point temperature being different from the second melting point temperature.

9. A multilayer film made by a coextrusion process, the film comprising:

a first outer layer of a blend of a first component and a second component, the first component selected from the group consisting of: (1) ethylene and alpha-olefin copolymers having a density of less than 0.915g/cc, (2) with acrylic acid C₁-C₁₇Alkyl ester copolymerized ethylene, (3) and C₁-C₁₇Ethylene copolymerized with an alkyl substituted alkyl acrylate and (4) a polymer containing ionic bonds, the proportion of the first component in the blend being 99% to 55% by weight, the proportion of the second component in the blend being 45% to 1% by weight and being selected from the group consisting of: (1) propylene-containing polymers, (2) polybutylene polymers, (3) polymethylpentene polymers, (4) cyclic olefin-containing polymers and (5) bridged polycyclic hydrocarbon-containing polymers;

wherein said film is non-oriented and said film is subjected to electron beam irradiation at a dose of 20kGy to 200 kGy.

10. The film of claim 9 wherein the second component is a blend of a first propylene containing polymer and a second propylene containing polymer.

11. The film of claim 10, wherein the first propylene containing polymer has a first melt flow rate and the second propylene containing polymer has a second melt flow rate, the first melt flow rate being 3 times the second melt flow rate.

12. The film of claim 10, wherein the first propylene containing polymer has a first melt flow rate and the second propylene containing polymer has a second melt flow rate, the first melt flow rate being 5 times the second melt flow rate.

13. The film of claim 10, wherein the first propylene containing polymer has a first melting point temperature and the second propylene containing polymer has a second melting point temperature, the first melting point temperature being at least 5 ℃ higher than the second melting point temperature.

14. The film of claim 10, wherein the first propylene containing polymer has a first melting point temperature and the second propylene containing polymer has a second melting point temperature, the first melting point temperature being at least 10 ℃ higher than the second melting point temperature.

15. The film of claim 10, wherein the first propylene containing polymer has a first melt flow rate and the second propylene containing polymer has a second melt flow rate, the first melt flow rate being different from the second melt flow rate.

16. The film of claim 10, wherein the first propylene containing polymer has a first melting point temperature and the second propylene containing polymer has a second melting point temperature, the first melting point temperature being different from the second melting point temperature.

17. A multilayer film, the film comprising:

a first layer of a blend of a first component and a second component, the first component selected from the group consisting of: (1) ethylene and alpha-olefin copolymers having a density of less than 0.915g/cc, (2) with acrylic acid C₁-C₁₇Alkyl ester copolymerized ethylene, (3) and C₁-C₁₇Alkyl substituted alkyl acrylate copolymerized ethylene and (4) an ionomer, the proportion of the first component in the blend being 99 to 55% by weight and the proportion of the second component in the blend being 45 to 1% by weight and consisting of a blend of the first propylene containing polymer and the second propylene containing polymer;

the film has an elastic modulus of less than 60,000psi as measured by ASTM D882, an internal haze of less than 25% as measured by ASTM D1003, an internal bond of greater than 2 such that the film can be formed into a roll and autoclaved and can be unwound after autoclaving, and a sample creep of less than or equal to 150% at 120 ℃ under a 27psi load for a film having a thickness of 5 mils to 15 mils, the film being heat sealable into a container having a seal which remains intact when the container is autoclaved at 121 ℃ for one hour.

18. The film of claim 17, wherein the first propylene containing polymer has a first melt flow rate and the second propylene containing polymer has a second melt flow rate, the first melt flow rate being 3 times the second melt flow rate.

19. The film of claim 17, wherein the first propylene containing polymer has a first melt flow rate and the second propylene containing polymer has a second melt flow rate, the first melt flow rate being 5 times the second melt flow rate.

20. The film of claim 17, wherein the first propylene containing polymer has a first melting point temperature and the second propylene containing polymer has a second melting point temperature, the first melting point temperature being at least 5 ℃ higher than the second melting point temperature.

21. The film of claim 17, wherein the first propylene containing polymer has a first melting point temperature and the second propylene containing polymer has a second melting point temperature, the first melting point temperature being at least 10 ℃ higher than the second melting point temperature.

22. The film of claim 17, wherein the first propylene containing polymer has a first melt flow rate and the second propylene containing polymer has a second melt flow rate, the first melt flow rate being different from the second melt flow rate.

23. The film of claim 17, wherein the first propylene containing polymer has a first melting point temperature and the second propylene containing polymer has a second melting point temperature, the first melting point temperature being different from the second melting point temperature.

24. A multilayer film, the film comprising:

a first outer layer of a blend of a first component and a second component, the first component being selected from the following: (1) ethylene and alpha-olefin copolymers having a density of less than 0.915g/cc, (2) with acrylic acid C₁-C₁₇Alkyl ester copolymerized ethylene, (3) and C₁-C₁₇Alkyl substituted alkyl acrylate copolymerized ethylene and (4) an ionomer, the proportion of the first component in the blend being 99 to 55% by weight and the proportion of the second component in the blend being 45 to 1% by weight and consisting of a blend of the first propylene containing polymer and the second propylene containing polymer;

25. The film of claim 24, wherein the first propylene containing polymer has a first melt flow rate and the second propylene containing polymer has a second melt flow rate, the first melt flow rate being 3 times the second melt flow rate.

26. The film of claim 24, wherein the first propylene containing polymer has a first melt flow rate and the second propylene containing polymer has a second melt flow rate, the first melt flow rate being 5 times the second melt flow rate.

27. The film of claim 24, wherein the first propylene containing polymer has a first melting point temperature and the second propylene containing polymer has a second melting point temperature, the first melting point temperature being at least 5 ℃ higher than the second melting point temperature.

28. The film of claim 24, wherein the first propylene containing polymer has a first melting point temperature and the second propylene containing polymer has a second melting point temperature, the first melting point temperature being at least 10 ℃ higher than the second melting point temperature.

29. The film of claim 18, wherein the first propylene containing polymer has a first melt flow rate and the second propylene containing polymer has a second melt flow rate, the first melt flow rate being different from the second melt flow rate.

30. The film of claim 18, wherein the first propylene containing polymer has a first melting point temperature and the second propylene containing polymer has a second melting point temperature, the first melting point temperature being different from the second melting point temperature.