JP2008247481A - Multiple layer film of new non-pvc material - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a multilayer film (10). <P>SOLUTION: This multilayer film (10) has a first layer (12) of a blend of a first component (selected from the group of (1) ethylene and α-olefin copolymers having a density of less than about 0.915 g/cc, (2) ethylene copolymerized with lower alkyl acrylates, (3) an ethylene copolymerized with lower alkyl substituted alkyl acrylates, and (4) ionomers), a second component (consisting of one or more polymers of the group of (1) propylene containing polymers, (2) polybutene polymers, (3) polymethylpentene polymers, (4) cyclic olefin containing polymers, and (5) bridged polycyclic hydrocarbon containing polymers), and a second layer (4) attached to the first layer (12), wherein, the first component is present in an amount from about 99% to about 55% by weight of the blend, and the second component is present in an amount by weight of the blend from about 45% to about 1 wt.%. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

(Technical field)
The present invention relates generally to polymer blends for making films, and more particularly has a slight strain and is non-adhesive in steam sterilization, heat stable, and flexible medical containers It is related with the film which is most suitable for processing into.

(Background of the Invention)
In the medical field, a beneficial agent is collected, processed and stored in a container, transported, and finally delivered to the patient by infusion from a tube to process the container when a therapeutic effect is reached. The material used must have a unique combination of properties. For example, visual inspection of the solution for particulate contaminants requires an optically clear container. The material that forms the wall must be flexible enough to inject the solution by folding the container wall without allowing air to enter the container. This material must maintain flexibility and toughness over a wide range of temperatures. Some solutions (e.g., premixed specific drug solutions) are stored in containers and moved, for example, at temperatures between -25 [deg.] C and -35 [deg.] C to minimize drug degradation, so this The material must maintain flexibility and toughness at low temperatures. This material is also functional to withstand the heat of steam sterilization (the process that most medical liquid containers and nutritional products are subjected to prior to shipment) and withstands strain at high temperatures. This sterilization process usually involves exposing the container to steam, typically at a temperature of 121 ° C. and elevated pressure.

  With regard to ease of manufacture into useful articles, it is desirable that the material be sealable using heat sealing techniques. Thus, the material must maintain sufficient thermoplastic properties to melt upon heating.

  A further requirement is to minimize the environmental impact in the disposal of items made from the material after the intended use. For these items that are disposed of in landfills, it is desirable to minimize or avoid the incorporation of low molecular weight leachable components to produce the item. Further benefits are realized through the use of materials that allow for thermal reprocessing of scrap material produced during manufacture.

  For those containers that are discarded via incineration to minimize biohazards, it is desirable to use materials that minimize or eliminate the formation of environmentally undesirable and corrosive inorganic acids Is done.

  It is desirable that this material be free of low molecular weight additives (eg, plasticizers, stabilizers, etc.) that can be released into pharmaceutical or biological fluids, but have low content.

Due to its ability to meet a wide range of functional requirements, flexible polyvinyl chloride (PVC) is frequently selected as a material for medical bag applications. PVC also offers the obvious advantage of being one of the most cost-effective materials for manufacturing devices that meet the above applications. However, PVC has many drawbacks on the market. These drawbacks include the incompatibility of PVC compounds with certain drugs, the relationship with respect to chlorine content and its effect on the environment, and, generally, increased passive market recognition of PVC. Thus, most materials have been invented and replaced with PVC. However, many alternative materials are too expensive to implement and still do not meet all of the above requirements.

  Polyolefins and polyolefin alloys have been developed that meet the many requirements of medical containers and tubing that do not have the disadvantages associated with PVC. Typically, polyolefins are compatible in medical applications because they have a relatively low extractability to liquids. Most polyolefins are environmentally friendly because they do not produce harmful degradation products on incineration and are suitable for thermoplastic reuse. Many polyolefins are cost effective materials that can provide an economical alternative to PVC. However, there are many obstacles to overcome the substitution of polyolefins with all the beneficial properties of PVC.

  For example, problems are encountered in the use of certain polyolefins to make medical tubing. Such tubing has been found to have poor surface properties, and as a result, when a tubing is sandwiched using a slide clamp, it is easy to cut, tear or scratch. Also, certain polyolefins (e.g., ultra low density polyethylene) having preferred modulus properties have a melting temperature below the temperature reached during the autoclave process.

  It is well known that crosslinking with chemical agents or by high energy ionizing irradiation increases the heat resistance of the polymer matrix. Chemical cross-linking is a covalent bond that crosses into separate polymer chains that greatly delays the tendency to deform and flow at higher temperatures above the melting point temperature of the polymer. U.S. Patent No. 6,057,031 to Terumo discloses by irradiating an ethylene vinyl acetate copolymer with a high energy (2 Mev) electron beam at a dose between 50 kGy and 100 hkGy to achieve a gel content between 50% and 85%. Disclosed is a vapor autoclavable medical container. U.S. Patent No. 6,057,049 discloses that when EVA sidewalls of containers are irradiated to achieve a gel content of about 50% or higher before being sealed together, they easily peel. (Column 4, lines 20-30). Therefore, patent document 11 discloses irradiating the side wall of a container after sealing a container to the pouch which only releases the port area | region which is not sealed.

  Similarly, U.S. Patent No. 6,057,031 discloses making medical containers from EVA and other materials. U.S. Patent No. 6,057,051 discloses a process for increasing the autoclave resistance of EVA by crosslinking the material using a high energy electron beam. The patent document 10 warns that the use of a heat seal is not possible if the cross-linking exceeds 50 percent (column 4, lines 27-35).

  Patent Document 1 discloses crosslinking a semi-rigid container made of EVA or a blend of EEA and polypropylene. This patent does not disclose the use of ethylene alpha-olefins with polypropylene. It is also disclosed that irradiation prior to formation results in an article with poor heat sealing ability (column 4, lines 25-28).

Both U.S. Pat. Nos. 6,028,096 and 6,037,037, assigned to the assignee, disclose a medical container having a coextruded high density polyethylene skin layer and a core layer of ethylene vinyl acetate copolymer having a vinyl acetate content of about 18%. After the container is made with a conventional radio frequency heat seal, the assembly is subjected to about 100 kGy of ionizing radiation from a high energy electron beam accelerator of about 5 Mev. The high density polyethylene layer acts as a moisture and gas permeation barrier to maintain the sterile liquid content at a relatively constant concentration as required by the world pharmacopoeia. However, several different disadvantages were evident in this material construction: 1) To process containers from this material product, as crosslinked EVA layers are difficult if not impossible to seal In addition, the container must be made before the cross-linking process (this makes it very inefficient for the manufacturing process); and 2) the irradiation dose required for sufficient cross-linking is also a sufficient amount Releases by-products of acetic acid upon irradiation. Since HDPE provides a barrier to gas permeation, trapped acetic acid makes the liquid contents quite acidic. This gives very undesirable results.

  W. R. U.S. Patent No. 6,057,037 to Grace discloses the production of medical solution containers from multi-layered materials, and in certain embodiments, a layer intended to be heat sealed is polypropylene as a major component. It is constructed using Polypropylene is well known to undergo chain scission when exposed to radiation and the heat seal layer is thermoplastic and can be heat sealed with similar surfaces. Thus, the entire multilayer film can be heat sealed and resists autoclaving. However, the complexity of the multi-layer construction and the possible need for washing and incorporation of acid scavenge compounds in the film (see US Pat. No. 5,677,059) to remove the acidic byproducts of washing EVA irradiation make the process very complex. It will be very expensive. Furthermore, the film is constructed from several very different materials, and the process of edge trim and other film scrap recycling is very difficult and cannot be performed without reducing optical and mechanical properties.

  U.S. Patent No. 6,057,031 discloses a multi-layer differentially crosslinked film, where the heat sealed layer includes additional antioxidants that retard crosslinking and facilitate heat sealing after crosslinking. Similarly, U.S. Patent No. 6,057,032 discloses another differentially crosslinked multilayer film in which the outer layer includes a crosslinking enhancer. However, these constructs are all multi-layer constructs and do not address the problem of self-adhesion during autoclaving.

U.S. Patent No. 6,057,037 to Sun discloses a multilayer, oriented, heat shrinkable container having a radiation cross-linked outer wall and a non-crosslinked inner seal layer controlled by a radiation process. The inner and outer layers can be EVA copolymers. This container is designed to shrink upon application of heat and is therefore unsuitable for containers that must substantially maintain the total volume after the autoclave process.
U.S. Pat. No. 4,401,536 U.S. Pat. No. 4,489,604 US Pat. No. 5,066,290 US Pat. No. 4,643,926 US Pat. No. 5,445,893 US Pat. No. 5,055,328 Canadian Patent No. 125,229 U.S. Pat. No. 4,724,176 US Pat. No. 5,879,768 U.S. Pat. No. 4,453,940 U.S. Pat. No. 4,465,487

The main objective of the present invention is generally superior to these materials, which we have known for a long time in the art and are either used commercially or are commercially available. It is to provide a polymer material. Properties of such materials include flexibility, optical clarity for visual inspection, and heat resistance sufficient to withstand a steam sterilization process at temperatures up to 121 ° C. that does not cause significant degradation or self-adhesion. It is done. The material can also be non-oriented, non-adhesive and sealed using heat sealing techniques. The material is also substantially free of low molecular weight leachable additives and can be safely disposed of by incineration without producing significant amounts of corrosive inorganic acids. Finally, the material serves as a cost-effective alternative to the various PVC formulations currently used for medical devices.

  Patent document 9 discloses a pouch for packaging a flowable material made from a material having a sealing layer of a polymer composition comprising: (A) (1) at least one of 5 to 95% Uniform branched, substantially linear ethylene / alpha-olefin interpolymer and (2) 5% to 95% high pressure low density polyethylene having a density from 0.916 g / cc to 0.930 g / cc Selected from the group consisting of 10 to 100 percent of blends of (B) ultra low molecular density polyethylene, linear low density polyethylene, high pressure low density polyethylene, ethylene vinyl acetate copolymer, and homogeneously branched linear ethylene polymer. 0 to 90% of one polymer. The patent of U.S. Pat. No. 6,057,881 does not disclose the process of exposing the blend to radiation and does not disclose blending polypropylene with a substantially branched, linear ethylene / α-olefin interpolymer.

  If more than one polymer is mixed to form the alloy composition, it is difficult to achieve all the above objectives simultaneously. For example, many alloys produce significant light scattering (thus they cannot meet the objective of optical clarity). Light scattering intensity (measured by haze) depends on the proximity of the composition domain size and the refractive index of the components in the micrometer (μ) range. As a general rule, the selection of components that can be fully processed to very small domain sizes and still have minimal refractive index mismatch is a difficult task. The present invention is provided to solve these and other problems.

(Summary of the Invention)
The present invention provides a non-PVC, non-oriented multilayer film. The film has at least a first layer and a second layer bonded together. This first layer is a blend of the first and second components. The first component is selected from the following group: (1) an ethylene and α-olefin interpolymer having a density less than about 0.915 g / cc, and (2) an ethylene and lower alkyl acrylate interpolymer. (3) interpolymers of ethylene and lower alkyl substituted alkyl acrylates, and (4) ionic polymers (commonly referred to as ionomers). The second component is selected from one or more of the following: (1) propylene-containing polymer, (2) butene-containing polymer, (3) polymethylpentene-containing polymer, (4) cyclic olefin-containing polymer, and (5 ) Crosslinked polycyclic hydrocarbon-containing polymer. The second component is present in an amount from about 35% to about 1% by weight of the blend.

  This film has an elastic modulus of less than about 60,000 psi when measured according to ASTM D882 and the following internal haze of less than about 25% when measured according to ASTM D1003, as defined below Has a self-adhesion ranking greater than about 2, has little or no adhesion to the overpouch material, has no more than 150% sample creep at 120 ° C. loading at about 27 psi, and the film Can be heat-sealed, where the seal remains intact when the fluid-filled container is autoclaved at 121 ° C. for 1 hour.

The present invention provides the following.
Item 1 Multi-layer film, the following:
A first layer of a blend of a first component and a second component, the first component comprising: (1) an ethylene and α-olefin having a density less than about 0.915 g / cc The second component is selected from the group of copolymers, (2) ethylene copolymerized with lower alkyl acrylates, (3) ethylene copolymerized with lower alkyl substituted alkyl acrylates, and (4) ionomers The following: (1) propylene-containing polymer, (2) poly
The first component comprising one or more polymers of the group of butene polymers, (3) polymethylpentene polymers, (4) cyclic olefin-containing polymers, and (5) crosslinked polycyclic hydrocarbon-containing polymers. Is present in an amount of about 99% to about 55% by weight of the blend, and the second component is in an amount of about 45% to about 1% by weight of the blend;
A second layer bonded to the first layer;
Including, and
The film has an elastic modulus of less than about 60,000 psi when measured according to ASTM D882, and the following internal haze of less than about 25% when measured according to ASTM D1003, from about 2 Having a large internal adhesion ranking and having a sample creep of no more than 150% for a film having a thickness of about 5 mils to about 15 mils at a load of 27 psi at 120 ° C., and the film is into a container with a seal Film where the seal remains intact when the container is autoclaved at 121 ° C. for 1 hour.
Item 2. The film of item 1, wherein the propylene-containing polymer is a homopolymer of polypropylene and one or more comonomers and propylene selected from α-olefins having from about 2 to about 17 carbons. A film selected from the group consisting of random and block copolymers with and random and block terpolymers.
Item 3 The film of item 2, wherein the second component is a copolymer of propylene and ethylene, the copolymer having an ethylene content of 1 to 6% by weight of the copolymer.
Item 4 The film of item 2, wherein the second component is a blend of a first propylene-containing polymer and a second propylene-containing polymer.
Item 5. The film of item 4, wherein the first propylene-containing polymer has a first melt flow rate and the second propylene-containing polymer has a second melt flow rate. Where the first melt flow rate is about 3 times greater than the second melt flow rate.
Item 6. The film of item 4, wherein the first propylene-containing polymer has a first melt flow rate and the second propylene-containing polymer has a second melt flow rate. A film wherein the first melt flow rate is about 5 times greater than the second melt flow rate.
Item 7 The film of item 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, Wherein the first melting point temperature is at least about 5 ° C. higher than the second melting point temperature.
Item 8. The film of item 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, Wherein the first melting point temperature is at least about 10 ° C. higher than the second melting point temperature.
Item 9 The film of item 1, wherein the cyclic olefin has from 5 to about 10 carbons in the ring.
Item 10 The film of item 9, wherein the cyclic olefin is selected from the group consisting of substituted and unsubstituted cyclopentene, cyclopentadiene, cyclohexene, cyclohexadiene, cycloheptene, cycloheptadiene, cyclooctene, and cyclooctadiene. The film.
Item 11 The film of item 1, wherein the crosslinked polycyclic hydrocarbon has at least 7 carbons.
Item 12. The film of item 11, wherein the bridged polycyclic hydrocarbon is selected from the group consisting of polycyclic hydrocarbons having at least 7 carbons.
Item 13 The film according to Item 1, wherein the α-olefin has 3 to 17 carbons. Item 14 The film according to Item 1, wherein the α-olefin has 4 to 8 carbons.
Item 15 The film of item 14, wherein the copolymer of ethylene and α-olefin is obtained using a single site catalyst.
Item 16. The film of item 1, wherein the blend is subjected to electron beam irradiation at an absorbed dose of about 20 kGy to about 200 kGy.
Item 17 The film according to Item 1, wherein the second layer is selected from the group consisting of a skin layer, a high-frequency sensitive layer, a water vapor barrier layer, a gas barrier layer, a scrap layer, a seal layer, and a core layer.
Item 18 Multilayer film, the following:
A first layer of a first component and a second component, the first component comprising: (1) a copolymer of ethylene and an α-olefin having a density of less than about 0.915 g / cc; The second component selected from the group of (2) ethylene copolymerized with lower alkyl acrylate, (3) ethylene copolymerized with lower alkyl substituted alkyl acrylate, and (4) ionomer, 1 of the group of: (1) propylene-containing polymer, (2) polybutylene polymer, (3) polymethylpentene polymer, (4) cyclic olefin-containing polymer, and (5) crosslinked polycyclic hydrocarbon-containing polymer Consisting of one or more polymers, wherein the first component is present in an amount from about 99% to about 55% by weight of the blend, and the second component is about 45% by weight of the blend. In an amount of about 1 wt%, the first layer;
A second layer bonded to the first layer;
Including, and
The film is subjected to electron beam irradiation at an absorbed dose of about 20 kGy to about 200 kGy.
Item 19 The film according to Item 18, wherein the film is
Has an elastic modulus of less than about 60,000 psi when measured according to ASTM D882, has an internal haze of less than about 25% when measured according to ASTM D1003, and an internal adhesion ranking greater than about 2. Having a sample creep of 150% or less for a film having a thickness of about 5 mils to about 15 mils at a loading of 27 psi at 120 ° C., and the film is heat sealed to a container having a seal Where the seal remains intact when the container is autoclaved at 121 ° C. for 1 hour.
Item 20. The film of item 18, wherein when exposed to the electron beam irradiation, the film is exposed to an oxygen partial pressure less than environmental conditions.
Item 21. The film of item 18, wherein the propylene-containing polymer is a polypropylene homopolymer and one or more comonomers selected from α-olefins having from about 2 to about 17 carbons and propylene. A film selected from the group consisting of random and block copolymers with and random and block terpolymers.
Item 22. The film of item 18, wherein the second component is a copolymer of propylene and ethylene, the copolymer having an ethylene content of 1 to 6% by weight of the copolymer.
Item 23 The film of item 18, wherein the second component is a blend of a first propylene-containing polymer and a second propylene-containing polymer.
Item 24. The film of item 23, wherein the first propylene-containing polymer has a first melt flow rate and the second propylene-containing polymer has a second melt flow rate. Where the first melt flow rate is about 3 times greater than the second melt flow rate.
Item 25. The film of item 23, wherein the first propylene-containing polymer has a first melt flow rate and the second propylene-containing polymer has a second melt flow rate. A film wherein the first melt flow rate is about 5 times greater than the second melt flow rate.
Item 26 The film according to Item 23, wherein the first propylene-containing polymer is
And a second propylene-containing polymer having a second melting point temperature, wherein the first melting point temperature is at least about 5 ° C. above the second melting point temperature. High, film.
Item 27. The film of item 23, wherein the first propylene-containing polymer has a first melting point temperature and the second propylene-containing polymer has a second melting point temperature, wherein Wherein the first melting point temperature is at least about 10 ° C. higher than the second melting point temperature.
Item 28 The film of item 18, wherein the cyclic olefin has from 5 to about 10 carbons in the ring.
Item 29 The film of item 28, wherein the cyclic olefin is selected from the group consisting of substituted and unsubstituted cyclopentene, cyclopentadiene, cyclohexene, cyclohexadiene, cycloheptene, cycloheptadiene, cyclooctene and cyclooctadiene. The film.
Item 30 The film of item 18, wherein the crosslinked polycyclic hydrocarbon has at least 7 carbons.
Item 31. The film of item 30, wherein the bridged polycyclic hydrocarbon is selected from the group consisting of polycyclic hydrocarbons having at least 7 carbons.
Item 32. The film of item 18, wherein the α-olefin has from 3 to 17 carbons.
Item 33 The film of item 18, wherein the α-olefin has from 4 to 8 carbons. Item 34. The film of item 32, wherein the copolymer of ethylene and α-olefin is obtained using a single site catalyst.
Item 35 The film according to Item 18, wherein the second layer is selected from the group consisting of a skin layer, a high-frequency sensitive layer, a water vapor barrier layer, a gas barrier layer, a scrap layer, a seal layer, and a core layer.

(Detailed explanation)
The present invention is possible in many different forms of embodiments. Preferred embodiments of this invention are disclosed with the understanding that this disclosure will be regarded as illustrative of the principles of the invention and is not intended to limit the broad aspects of the invention to the illustrated embodiments.

(I. Polymer mixture and monolayer film thereof)
FIG. 1 shows a monolayer film 10 of the present invention. This single layer film 10 is made from a polymer mixture having a first component and a second component. The first component is selected from the following group: (1) an interpolymer of ethylene and an α-olefin having a density less than about 0.915 g / cc, and (2) an interpolymer of ethylene and a lower alkyl acrylate. Polymers, (3) interpolymers of ethylene and lower alkyl substituted alkyl acrylates, and (4) ionic polymers (commonly referred to as ionomers). The first component is present in an amount from about 99% to about 55% by weight of the mixture, more preferably from about 60% to 85%, most preferably from about 65% to 80%. .

  This second component is selected from the group consisting of: (1) a propylene-containing polymer, (2) a butene-containing polymer, (3) a polymethylpentene-containing polymer, (4) a cyclic olefin-containing polymer, and (5 ) Crosslinked polycyclic hydrocarbon-containing polymer. The second component is present in an amount from about 45% to about 1% by weight of the mixture, more preferably from about 15% to 40%, most preferably from about 20% to 35%. .

This film has an elastic modulus of less than about 60,000 psi when measured according to ASTM D882, an internal haze of less than about 25% when measured according to ASTM D1003,
Has a self-adhesion rank (defined below) greater than about 2, with little or no adhesion to the overpouch material, and less than 150% sample creep at 27 psi load at 120 ° C. And the film can be heated and sealed in a container with a seal, where the seal remains intact when the liquid-filled container is autoclaved at 121 ° C. for 1 hour.

  As used herein, the term “interpolymer” includes either random or block copolymers, terpolymers.

  Suitable ethylene and α-olefin interpolymers preferably have a density of less than about 0.915 g / cc, as measured by ASTM D-792, and are usually very low density polyethylene ( VLDPE), ultra low density ethylene (ULDPE) and the like. The α-olefin should have 3 to 17 carbons, more preferably 4 to 12 and most preferably 4 to 8 carbons. In a preferred form of the invention, the ethylene and α-olefin copolymer is obtained using a single site catalyst. Suitable single site catalyst systems are the catalysts disclosed in US Pat. Nos. 5,783,638 and 5,272,236, among others. Suitable copolymers of ethylene and α-olefin include ethylene and the trade name AFFINITY by Dow Chemical Company, ENGAGE by Dupont-Dow, and EXACT and PLASTOMER by Exxon. Mention may be made of copolymers with α-olefins.

  The term “lower alkyl acrylate” refers to a comonomer having the formula set forth in FIG.

このＲ基は、１〜１７個の炭素を有するアルカンをいう。従って、用語「低級アルキルアクリレート」には、メチルアクリレート、エチルアクリレート、ブチルアクリレートなどが挙げられるがこれらに限定されない。

The R group refers to an alkane having 1 to 17 carbons. 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 set forth in Scheme 2:

Ｒ_１およびＲ_２は、１〜１７個の炭素を有するアルカンであり、そして同じ数の炭素を有するか、または異なる数の炭素を有し得る。従って、用語「アルキル置換アルキルアクリレート」には、メチルメタクリレート、エチルメタクリレート、メチルエタクリレート、エチルエタクリレート、ブチルメタクリレート、ブチルエタクリレートなどが挙げられるがこれらに限定されない。

R ₁ and R ₂ are alkanes having 1 to 17 carbons and may have the same number of carbons or different numbers of carbons. 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 polymers selected from the group consisting of homopolymers of polypropylene, copolymers of one or more comonomers selected from α-olefins having 2 to 17 carbons and propylene, and terpolymers. Can be mentioned. Suitable polypropylene copolymers and terpolymers include random or block propylene and ethylene copolymers, or random or block propylene / ethylene / butene terpolymers. Suitable propylene and α-olefin copolymers are sold by Montell under the trade names PRO FAX, PRO FAX ULTRA and CATALLOY.

The present invention also contemplates using a mixture of propylene-containing polymers as the second component of this mixture. In a preferred form of the invention, the mixture comprises at least a first propylene-containing polymer and a second propylene-containing polymer. This first propylene-containing polymer and second propylene-containing polymer may be selected from the propylene homopolymers, copolymers and terpolymers described above. In a preferred form of the invention, the first propylene-containing polymer differs from the second propylene-containing polymer in at least one of two ways. This first difference is that the first propylene-containing polymer has a melt flow rate that is preferably 3 times faster and more preferably 5 times higher than that of the second propylene-containing polymer. It should be. The second difference is that the first propylene-containing polymer preferably has a melting point that is at least about 5 ° C. higher than the melting point of the second propylene-containing polymer, and more preferably at least about 10 ° C. higher. This melting point is determined by ASTM D3417 (Enthalpies of Fusion and Crystallization of Polymers by Differential Scanning).
Measured according to Calorimetry). The first propylene-containing polymer can differ from the second propylene-containing polymer by this first difference, only the second difference, or both.

Homopolymers and copolymers of suitable cyclic olefins and bridged polycyclic hydrocarbons, and blends thereof are described in US Pat. Nos. 5,218,049, 5,854,349, 5,863. , 986, 5,795,945, 5,792,824; and European Patents EP 0 291 208, EP 0 283,164, EP
0 497,567, which are incorporated herein by reference in their entirety and make part of this specification.

  In preferred forms of the invention, suitable cyclic olefin monomers are monocyclic compounds having from 5 to about 10 carbons in the ring. The cyclic olefin may be selected from the group consisting of substituted or unsubstituted cyclopentene, cyclopentadiene, cyclohexene, cyclohexadiene, cycloheptene, cycloheptadiene, cyclooctene, cyclooctadiene. Suitable substituents include lower alkyl, acrylate derivatives and the like.

  In preferred forms of the invention, suitable bridged polycyclic hydrocarbon monomers have two or more rings and more preferably contain at least 7 carbons. The ring may be substituted or unsubstituted. Suitable substituents may include lower alkyl, aryl, aralkyl, vinyl, allyloxy, (meth) acryloxy, and the like. The bridged polycyclic hydrocarbon is selected from the group consisting of the hydrocarbons disclosed in the patents and patent applications incorporated above. Suitable bridged polycyclic hydrocarbon-containing polymers are TICONA under the trade name TOPAS, Nippon Zeon under the trade names ZEONEX and ZEONOR, Daikyo Gomu Seiko under the trade name CZ resin, and Mitsui Petrochemical Company under the trade name APEL. Sold by name.

  In a preferred form of the invention, the film has the following physical characteristics: (1) an elastic modulus of less than about 60,000 psi when measured according to ASTM D882, and (2) about 25 when measured according to ASTM D1003. Internal haze of less than%, (3) self-adhesion ranking greater than about 2, as defined below, (4) no adhesion to overpouch material, (5) at 120 ° C., at a load of about 27 psi, (6) The film can be heated and sealed in a container with a seal, where the container filled with liquid is autoclaved at 121 ° C. for 1 hour. If left untouched, it remains intact.

The film is also sufficiently flexible to build a container of flowable material. The film has a modulus of elasticity of less than about 60,000 psi, more preferably less than about 40,000 psi, even more preferably less than about 30,000 psi, and most preferably when measured according to ASTM D-882. Has an elastic modulus of less than about 20,000 psi. This flowable material container is an I.D. V. In the case of a container, it is desirable to fold or substantially fold this container upon spill and, therefore, ASTM
When measured according to D-882, it should have a modulus of elasticity less than about 40,000 psi, more preferably less than about 30,000 psi, 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 a film to adhere to itself during autoclaving. This property can be determined by the following test. The film strip is cut to 8 inches x 2 inches to a larger dimension in the machine direction. These pieces are rolled into a 2 inch long tube approximately 0.5 inch in diameter. The rolled film is held in place with a paper clip by pressing the film layers together at one edge. The tube is then placed in a steam autoclave at 121 ° C. for 30 minutes. The sample is allowed to cool at room temperature for at least 1 hour. The tube is then wound up. The resistance to this winding and the relative damage to this film are ranked as shown in Table 1 below:
Table 1
Rank Observation result 1 This film cannot be wound up without destroying the film.
2 This film is difficult to peel off and results in significant surface damage.
3 Notice some resistance to peeling and slight surface damage.
4 Notice little resistance to scratching with little or little surface damage.
5 Not aware of tear resistance and surface damage.
The rank is determined by 3 or more individuals and recorded as an average.

  Adhesion to the overpouch material is determined by the following qualitative test. A 1 inch wide film strip is sealed in a typical overpouch bag (medium or high density polyethylene). The overpouch bag is then placed in a laboratory autoclave at 252 ° F. and 24.5 psig gauge pressure for 1 hour. After autoclaving, the bag is opened and a small piece is removed. If the film is separated from the overpouch without leaving a mark of damage on the film surface, a rank of no adhesion (N) is given. If this film separation causes visible damage, the rank is given (Y), indicating that there is adhesion to the overpouch. A rank showing a slight adhesion (S) can also be given.

  By clamping a film piece having a thickness of about 5 mils to about 15 mils in a temperature controlled oven at 120 ° C. and weighting to produce a pressure of about 27 psi, It has been determined. After 40 minutes of loading, the film strip was removed and the dimensional change in the previously labeled 1 inch gap was recorded.

  The film can be sealed using standard heat sealing techniques. If a fluid container (eg, as described in FIG. 3) is made from this film by sealing the peripheral edge to define a centrally located fluid chamber, an appropriate heat seal is formed. Is done. The container is filled with water and subjected to a standard autoclave sterilization process. A suitable heat seal remains intact upon completion of the autoclave cycle.

  The films of the present invention have a haze of less than about 25%, most preferably less than about 15%, as measured according to ASTM D1003. For the purposes of the present invention, internal haze is defined as the haze value measured when both film surfaces are wetted with isopropyl alcohol.

(II. Processing of polymer and film)
To produce the film of the present invention, the raw material is fed into the extrusion hopper at the desired mixing ratio using a weight feeder. This material is extruded using an extrusion die to produce a single layer film. This film is irradiated with a suitable energy source and then sealed to form a fluid container. It is also contemplated that the blend is exposed to radiation prior to extrusion. This raw material can also be pre-blended prior to extrusion using single screw, double screw or other mixing methods known to those skilled in the art.

  A preferred method of irradiating the film is to irradiate the film with an electron beam at a beam energy of about 150 Kev to 10 Mev, more preferably 200 to 300 Kev, and a dose of about 20 kGys to about 200 kGys, and more preferably about 60 to 150 kGys. To be exposed to. Alternatively, the film can be crosslinked using techniques known to those skilled in the art. Cross-linking methods used in the industry include exposure to ionizing radiation (gamma rays, beta rays, ultraviolet light, etc.) and chemical reactions (peroxidation and condensation reactions).

  In order to reduce or minimize the oxidative degradation of this film during and after electron beam exposure, it is desirable to reduce the oxygen partial pressure in the area surrounding the film exposed to irradiation. This oxygen partial pressure can be reduced by applying a vacuum, or by applying another gas, such as pressurized nitrogen, or by other known techniques for achieving this goal. In a preferred form of the invention, the oxygen concentration during nitrogen flow is less than about 100 ppm, more preferably less than about 40 ppm.

(III. Multilayer film)
FIG. 2 shows an example of a multilayer film 20 comprising a single layer 12 as described above. In a preferred form of the invention, this monolayer film should be a sealing layer. This multi-layer film 20 may be any additional layer 14 or layers such as skin layers, high frequency sensitive layers, water vapor barrier layers, gas barrier layers, fragment layers, seal layers and core layers, to name a few. Additional layer combinations selected from:

  This skin layer can be added to increase the scuff resistance of the film. The skin layer can be an olefin material such as homopolymers and copolymers of propylene and ethylene. The skin layer can also be a polyester, copolyester, polyamide or copolyamide. The term “copolyester” and the like applies to polyesters synthesized from more than one diol and dibasic acid. As used herein, a copolyester is also characterized as a copolymer of polyether and polyethylene terephthalate. More preferably, as used herein, the copolyester is 1,4 cyclohexanedimethanol, 1,4 cyclohexanedicarboxylic acid, and polytetramethylene glycol ether as reactants, or any equivalent of the above Characterized as a polymeric material derived from the product.

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

  A suitable gas barrier is a barrier that inhibits the passage of oxygen, carbon dioxide or other gases. Suitable gas barriers include, but are not limited to, polyesters and polyamides.

  The piece material produced prior to irradiation can be incorporated into one or more layers.

(IV. Container of flowable material)
FIG. 3 shows a container of flowable material, and in particular I.D. V. A container 30 is shown. FIG. V. An administration set 40 is shown and FIG. 5 shows a peritoneal dialysis set 50. The present invention further contemplates the manufacture of medical tubes from the mixtures of the present invention. Although the radiation treatment of the tube differs from the film due to the increased thickness and tube roundness, the tube can be effectively processed within the irradiation energy range described above for the film. What is meant by “flowable material” is a material that flows by gravity. Thus, flowable materials include both liquid articles and powder or granular articles. The container 30 has a side wall 32 that is positioned and sealed along a peripheral edge that defines a chamber 34 for containing a flowable material, such as a liquid or granular material. For containers made only by blow molding or blow extrusion, the longitudinal ends are sealed. A port tube 36 or a plurality of port tubes are provided to fill and empty the contents of the container 30. The sidewall and port tube are made from one of the single or multilayer films described above. Surprisingly, the medical articles made from this film and the blends described above can be heat sealed even when the film is irradiated with electron beam radiation.

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

(V. Double chamber peelable seal container)
FIG. 6 shows a dual chamber container 70 having a first chamber 72 and a second chamber 74 separated by a peelable seal 76. This container sidewall 75 is made from one of the polymer blends, single layer films or multilayer films described above. The dual chamber container can be used for many applications, for example, containing the two components separately for later mixing. This component can be a liquid or a powder. This peelable seal can be made by modifying the sealing conditions so that the peelable seal 76 can be ruptured by applying force to the side wall 75 of the container. Typically, one of the chambers contains a liquid. By squeezing the container side wall 75 against the chamber containing the liquid, the liquid contents flow toward the peelable seal 76, and by applying sufficient pressure, the seal 76 is ruptured and stored in a separate chamber. The ingredients can be mixed.

  Although FIG. 6 shows only one peelable seal 76, it is contemplated that many peelable seals can be provided to create many chambers. In addition, FIG. 6 shows a peelable seal that runs between the lateral edges. It is also contemplated that the peelable seal may extend between the longitudinal ends or simply around the area that does not cross the permanent peripheral seam 79 that defines the chamber.

  This peelable seal 76 can be made simultaneously with sealing the peripheral sidewalls or before or after making a permanent peripheral seal. This peelable seal 76 can be made by controlling the sealing conditions. A peelable seal can be applied at lower temperatures and pressures than used to provide a permanent perimeter seal, or by shortening the seal time used to provide a permanent seal, etc. Produced. This further enhancement of peelable characteristics can be obtained by local modification of the surface characteristics of the film (corona treatment or other suitable treatment).

  It is contemplated that the container can be sealed using ultrasonic welding techniques, conductive heat sealing techniques and other techniques well known in the art.

(VI. Example)
The blends identified in the table below were made into monolayer films using an extrusion process. The film was exposed to electron beam radiation having an acceleration voltage of 200 Kev to 300 Kev at the doses listed in the table below:

Dow Affinity PL 1880 is an ULDPE with a density of 0.902 g / cc.
DuPont Dow Engage 8003 is a ULDPE with a density of 0.885 g / cc.
Exxon PP305GE1 is a homopolymer of propylene (MFR 440).
Montell SA-861 is a propylene and ethylene copolymer (MFR).
6.5).
Montell SA 982 is a propylene and ethylene copolymer (MFR).
100).
“NA” means unusable.

FIG. 1 is a cross-sectional view of a single layer film of the present invention. FIG. 2 is a cross-sectional view of the multilayer film of the present invention. FIG. 3 is a material container made from the film of the present invention. FIG. V. Fluid dosing set. FIG. 5 is a peritoneal dialysis container and tubing set. FIG. 6 is a dual chamber bag with a peelable seal separating the chambers.

Claims (1)

Invention described in the specification .

Images