HK1165374A - Non-pvc films having barrier layer - Google Patents

Description

non-PVC film with barrier layer

Background

The present disclosure generally relates to polymer films. More particularly, the present disclosure relates to non-PVC polymeric films that include novel peel seal and/or barrier layers.

Multilayer coextruded films are widely used in a variety of industries, including for example in containers for packaging food or medical solutions. One of the desirable properties of a multilayer extruded film is its toughness or ability to resist damage in use or transport. Another desirable property is the ability to make peel seals of the desired strength suitable for the application and permanent seals to permanently enclose the container. Yet another desirable property is to provide a barrier to gases such as oxygen, carbon dioxide or water vapor in order to maintain the stability of the contained solution.

Conventional flexible polyvinyl chloride materials have also typically been used to make medical grade containers. Polyvinyl chloride ("PVC") is a cost-effective material for constructing such devices. However, PVC can produce harmful amounts of hydrogen chloride (or hydrochloric acid when contacted with water) upon incineration. PVC sometimes contains plasticizers that can leach into drugs or biological fluids or tissues that come into contact with the PVC formulation.

Summary of the invention

The present disclosure generally relates to films having peel seal and/or barrier layers. In one general embodiment, the present disclosure provides a film comprising a peel seal layer comprising a blend of a polypropylene (PP) random copolymer having a melting temperature greater than 140 ℃, a styrene-ethylene-butylene-styrene block copolymer (SEBS), and a Linear Low Density Polyethylene (LLDPE) having a melting temperature greater than 115 ℃.

In one embodiment, the blend comprises from about 60% to about 80% by weight of a polypropylene random copolymer having a melting temperature greater than 140 ℃, from about 15% to about 30% by weight of a styrene-ethylene-butylene-styrene block copolymer, and from about 2.5% to about 20% by weight of an LLDPE having a melting temperature greater than 115 ℃.

In another embodiment, the blend comprises about 70 weight percent of a polypropylene random copolymer having a melting temperature greater than 145 ℃, about 22.5 weight percent of a styrene-ethylene-butylene-styrene block copolymer, and about 7.5 weight percent of an LLDPE having a melting temperature greater than 120 ℃. The LLDPE can be an ethylene-octene-1 copolymer, an ethylene-hexene-1 copolymer, or a combination thereof.

In one embodiment, the film comprises a skin layer and a barrier layer. For example, the skin layer and peel seal layer may be attached to the barrier layer on opposite sides of the barrier layer. The skin layer may comprise a polypropylene random copolymer, a polypropylene homopolymer, a polypropylene-based TPO, nylon, styrene-ethylene-butylene-styrene block copolymer, copolyester ether, or a combination thereof. The barrier layer may comprise a polyamide (nylon), such as polyamide 6, 6/6, 10 copolymer, polyamide 6, amorphous polyamide, rubber modified nylon, or a combination thereof.

In one embodiment, the film comprises at least one tie layer that attaches at least one of the skin layer and the peel seal layer to the barrier layer. The tie layer may comprise maleated LLDPE, maleated polypropylene homopolymer, maleated polypropylene copolymer, maleated TPO, or combinations thereof.

In another embodiment, the present disclosure provides a film comprising a peel seal layer comprising a blend of a polypropylene random copolymer having a melting temperature greater than 140 ℃ and an ethylene-propylene rubber modified polypropylene elastomer. The blend may comprise from about 20 wt% to about 40 wt% of the polypropylene random copolymer and from about 60 wt% to about 80 wt% of the ethylene-propylene rubber modified polypropylene elastomer.

In one embodiment, the film may comprise a skin layer, a sealant layer, and a barrier layer. The skin layer and peel seal layer may be attached to the barrier layer on opposite sides of the barrier layer. The skin layer may comprise a polypropylene homopolymer, polypropylene random copolymer, polypropylene-based TPO, polyamide (nylon), styrene-ethylene-butylene-styrene block copolymer, copolyester ether, or combinations thereof. The barrier layer may comprise one or more polyamides (nylons), such as polyamide 6, 6/6, 10 copolymer, amorphous polyamide, rubber modified, or combinations thereof. The film may further comprise at least one adhesive layer that attaches at least one of the skin layer and the peel seal layer to the barrier layer.

In an alternative embodiment, the present disclosure provides a film comprising a barrier layer comprising a caprolactam-free nylon compound. The caprolactam-free nylon compound may comprise a blend of about 75% to about 95% by weight of the polyamide 6, 6/6, 10 copolymer and about 5% to about 25% by weight of the amorphous polyamide. In another embodiment, the caprolactam-free nylon compound comprises a blend of about 87.5 weight percent of the polyamide 6, 6/6, 10 copolymer and about 12.5 weight percent of the amorphous polyamide.

In one embodiment, a film having a caprolactam-free nylon barrier layer may comprise a skin layer and a peel seal layer. The skin layer and peel seal layer may be attached to the barrier layer on opposite sides of the barrier layer. The skin layer may comprise a polypropylene homopolymer, polypropylene random copolymer, polypropylene-based TPO, polyamide (nylon), styrene-ethylene-butylene-styrene block copolymer, copolyester ether block copolymer, or combinations thereof. The peel seal layer may comprise a blend of a polypropylene random copolymer having a melting temperature greater than 140 ℃, a styrene-ethylene-butylene-styrene block copolymer, and an LLDPE having a melting temperature greater than 120 ℃. The film may further comprise at least one adhesive layer that attaches at least one of the skin layer and the peel seal layer to the barrier layer.

In one embodiment, the film may include a core layer positioned between the skin layer and the peel seal layer, such as between the skin layer and the barrier layer or between the peel seal layer and the barrier layer. The core layer may comprise a propylene-ethylene copolymer, a syndiotactic propylene-ethylene copolymer, a polypropylene elastomer, a polypropylene homopolymer, a propylene-based elastomer, an ethylene-based elastomer, a styrene-ethylene-butylene-styrene block copolymer, an ethylene-propylene rubber modified polypropylene, or a combination thereof.

In another embodiment, the film may be used to make any suitable container, for example for containing a substance, such as a pharmaceutical or medical compound or solution. The present disclosure provides a container comprising a first sidewall and a second sidewall sealed together along at least one peripheral edge to define a fluid chamber. At least one of the first and second sidewalls of the container comprises at least one of: 1) a peel seal layer comprising a blend of a polypropylene random copolymer having a melting temperature greater than 140 ℃, a styrene-ethylene-butylene-styrene block copolymer, and an LLDPE having a melting temperature greater than 115 ℃; 2) a peel seal layer comprising a blend of a polypropylene random copolymer having a melting temperature greater than 140 ℃ and an ethylene-propylene rubber modified polypropylene elastomer; and 3) a barrier layer comprising a caprolactam-free nylon compound.

In an alternative embodiment, the present disclosure provides a multi-chambered container comprising a body defined by a film. The body may comprise more than two chambers separated by a peelable seal. The film may comprise at least one of the following: 1) a peel seal layer comprising a blend of a polypropylene random copolymer having a melting temperature greater than 140 ℃, a styrene-ethylene-butylene-styrene block copolymer, and an LLDPE having a melting temperature greater than 115 ℃; 2) a peel seal layer comprising a blend of a polypropylene random copolymer having a melting temperature greater than 140 ℃ and an ethylene-propylene rubber modified polypropylene elastomer; and 3) a barrier layer comprising a caprolactam-free nylon compound.

It is an advantage of the present disclosure to provide improved non-PVC films.

Another advantage of the present disclosure is to provide an improved peel seal layer for polymeric films.

It is yet another advantage of the present disclosure to provide an improved barrier layer for polymeric films.

Yet another advantage of the present disclosure is to provide an improved method of making non-PVC films.

Another advantage of the present disclosure is to provide an improved container comprising a non-PVC film.

Additional features and advantages are described herein, and will be apparent from, the following detailed description and the figures.

Drawings

FIG. 1 is a cross-sectional view of a monolayer film in an embodiment of the present disclosure.

Fig. 2 is a cross-sectional view of a five-layer film in an embodiment of the present disclosure.

Fig. 3 is a cross-sectional view of a six-layer film in an embodiment of the present disclosure.

Fig. 4 is a cross-sectional view of a container made from a film in an embodiment of the present disclosure.

FIG. 5 is a cross-sectional view of a multi-chamber container made from a film in an embodiment of the present disclosure.

Fig. 6 is a graph showing peel seal performance of a multilayer film.

Fig. 7 is a graph showing peel seal performance of a multilayer film.

FIG. 8 is a typical peel seal curve showing different film formulations.

Fig. 9(a) - (c) are cross-sectional views of multilayer films in embodiments of the present disclosure.

Detailed Description

The present disclosure generally relates to films having peel seal and/or barrier layers. The present disclosure provides monolayer films as well as multilayer films useful for packaging applications.

The films in embodiments of the present disclosure have improved toughness and peel seal capability while maintaining good gas barrier properties. This can be achieved by compounding materials to provide an appropriate sealing layer that can provide an appropriate peel seal range and toughness, and selecting a skin layer that improves the toughness of the film. In one embodiment, the peel seal layer and barrier film can have properties such as toughness or ability to absorb impact energy, sterilizability at 121 ℃, low haze, gas barrier, peel seal ability with heat seal machines, and cost effective properties.

In the general embodiment shown in fig. 1, the present disclosure provides a film 10 comprising a peel seal layer comprising a blend of a polypropylene (PP) random copolymer having a melting temperature greater than 140 ℃, a styrene-ethylene-butylene-styrene block copolymer, and an LLDPE having a melting temperature greater than 115 ℃. Suitable polypropylene random copolymers include those sold under the tradenames HUNTSMAN and Borealis under the tradenames Borealis and TOTAL by Flint hills resources. Suitable styrene-ethylene-butylene-styrene block copolymers include those sold by Kraton under the Kraton trade name. Suitable LLDPEs include those sold under the trade names Exxon and Dow DOWLEX.

In one embodiment, the peel seal layer blend contains from about 60% to about 80% by weight of a polypropylene random copolymer having a melting temperature greater than 140 ℃, from about 15% to about 30% by weight of a styrene-ethylene-butylene-styrene block copolymer, and from about 2.5% to about 20% by weight of an LLDPE having a melting temperature greater than 120 ℃. In another embodiment, the blend comprises about 70 weight percent of a polypropylene random copolymer having a melting temperature greater than 145 ℃, about 22.5 weight percent of a styrene-ethylene-butylene-styrene block copolymer, and about 7.5 weight percent of an LLDPE having a melting temperature greater than 120 ℃. The LLDPE can be an ethylene-octene-1 copolymer, an ethylene-hexene-1 copolymer, or a combination thereof.

In the embodiment shown in fig. 2, the film is a five-layer film having a skin layer 20, a barrier layer 24, and a peel seal layer 28. For example, the skin layer 20 and the peel seal layer 28 may be attached directly or indirectly to the barrier layer 24 on opposite sides of the barrier layer 24. The skin layer 20 may comprise a polypropylene random copolymer, a polypropylene homopolymer, nylon, styrene-ethylene-butylene-styrene block copolymer, copolyester ether, or a combination thereof. The barrier layer may comprise one or more polyamides (nylons), such as polyamide 6, 6/6, 10 copolymer, amorphous polyamide, or combinations thereof. Suitable polypropylene homopolymers include those sold under the trade name HUNTSMAN by Flint Hills Resources. Suitable nylons include those sold by EMS under the GRIVORY and GRILON tradenames. Suitable ethylene-propylene rubber-modified polypropylene elastomers include those sold by Mitsubishi under the ZELAS trade name.

In the embodiment shown in fig. 2, the multilayer film includes one or more tie layers 22 and 26 for attaching the skin layer 20 and/or the peel seal layer 28 to the barrier layer 24. Tie layers 22 and 26 may comprise any suitable adhesive material, such as maleated LLDPE, maleated polypropylene homopolymer, maleated polypropylene copolymer, maleated polypropylene-based TPO, or combinations thereof.

In another embodiment, the present disclosure provides a film comprising a peel seal layer comprising a blend of a polypropylene random copolymer having a melting temperature greater than 145 ℃ and an ethylene-propylene rubber modified polypropylene elastomer. The blend may contain from about 20 wt% to about 40 wt% of a polypropylene random copolymer having a melting temperature greater than 140 ℃ and from about 60 wt% to about 80 wt% of an ethylene-propylene rubber modified polypropylene elastomer.

In one embodiment, the film may further comprise a skin layer and a barrier layer. The skin layer and peel seal layer may be attached to the barrier layer on opposite sides of the barrier layer. The skin layer may comprise a polypropylene homopolymer, a polypropylene random copolymer, a polypropylene-based elastomer, a polyamide (nylon), a styrene-ethylene-butylene-styrene block copolymer, a copolyester ether block copolymer, or a combination thereof. The barrier layer may comprise one or more polyamides (nylons), such as polyamide 6, 6/6, 10 copolymer, amorphous polyamide, or combinations thereof. The film may further include at least one adhesive layer that attaches at least one of the skin layer and the peel seal layer to the barrier layer.

Films comprising barrier layers in embodiments of the present disclosure may comprise caprolactam-free nylon barrier materials that have good gas barrier resistance and sufficient toughness when used in multilayer films for medical solution container applications. Traditionally, nylon-6 (polyamide-6) or nylon-6 based blends have provided a good combination of gas barrier resistance and impact resistance. However, in some countries such as japan, korea and china, nylon-6 cannot be used for plastic solution container use due to their pharmacopoeia requirements. The pharmacopoeial requirements of these countries include limitations on the UV/visible wavelength of the compounds extracted from the container film material into solution; these limitations severely limit the amount of caprolactam that can be tolerated in the container film. Because polyamide-6 is synthesized from caprolactam, its presence will cause the container film to be substandard when used at a thickness that provides effective barrier properties.

In an alternative embodiment, the present disclosure provides a film comprising a barrier layer comprising a caprolactam-free nylon (i.e., polyamide or PA) compound. The caprolactam-free nylon compound may comprise a blend of about 75% to about 95% by weight of the polyamide 6, 6/6, 10 copolymer and about 5% to about 25% by weight of the amorphous polyamide. In another embodiment, the caprolactam-free nylon compound comprises a blend of about 87.5 weight percent of the polyamide 6, 6/6, 10 copolymer and about 12.5 weight percent of the amorphous polyamide. Suitable amorphous polyamides include, but are not limited to, polyamide 6I/6T and polyamide MXD6/MXDI copolymers.

In the embodiment shown in fig. 3, the film comprises a skin layer 30, a caprolactam-free nylon barrier layer 36, and a peel seal layer 40. The skin layer 30 and peel seal layer 40 may be attached to the barrier layer 36 on opposite sides of the barrier layer. The skin layer 30 may comprise a polypropylene homopolymer, a polypropylene random copolymer, a polypropylene-based TPO, a polyamide (nylon), a styrene-ethylene-butylene-styrene block copolymer, a copolyester ether block copolymer, or a combination thereof. The peel seal layer 40 may comprise a blend of a polypropylene random copolymer having a melting temperature greater than 140 ℃, a styrene-ethylene-butylene-styrene block copolymer, and an LLDPE having a melting temperature greater than 115 ℃.

As shown in fig. 3, the film may further include a core layer 32 positioned between the skin layer 30 and the barrier layer 36. The core layer 32 may comprise a propylene-ethylene random copolymer, a syndiotactic propylene-ethylene copolymer, a polypropylene elastomer, a polypropylene homopolymer, a propylene-based elastomer, an ethylene-based elastomer, a styrene-ethylene-butylene-styrene block copolymer, an ethylene-propylene rubber modified polypropylene, and combinations thereof. Suitable propylene-ethylene copolymers include those sold under the tradename VISTAMAXX by EXXON, VERSIFY by Dow, ATOFINA by Total, and PROFAX by Basell. The film may also include one or more tie layers 34 and 38 that attach the skin layer 30, the peel seal layer 40, the barrier layer 36, and/or the core layer 34 to one another.

The films in embodiments of the present disclosure may be used to make any suitable container, such as a container for holding a substance, such as a pharmaceutical or medical compound or solution. In the embodiment shown in fig. 4, the present disclosure provides a container 50 comprising a first sidewall 52 and a second sidewall (not shown) opposite the first sidewall, along with a peripheral seam 54, defining a fluid chamber. The container 50 may contain one or more port tubes 56 and 58 for filling and emptying the contents of the container 50. Any one or more of the sidewalls may be fabricated from one of the single or multilayer films set forth above. It will also be appreciated that the container may be formed by sealing the open end of a squeeze tube type film. In this case, the peripheral seam 54 may be formed by two seams on opposite ends of the tube. The container may be constructed such that the seams are at the top and bottom of the container or along the vertical sides thereof.

In one embodiment, the first sidewall and/or the second sidewall of the container is a film of at least one of: 1) a peel seal layer comprising a blend of a polypropylene random copolymer having a melting temperature greater than 140 ℃, a styrene-ethylene-butylene-styrene block copolymer, and an LLDPE having a melting temperature greater than 115 ℃; 2) a peel seal layer comprising a blend of a polypropylene random copolymer having a melting temperature greater than 140 ℃ and an ethylene-propylene rubber modified polypropylene elastomer; and 3) a barrier layer comprising a caprolactam-free nylon compound.

In an alternative embodiment shown in FIG. 5, the present disclosure provides a multi-chamber container 70 comprising a body 72 defined by a film. The multi-chamber container 70 contains two chambers 74 and 76. It will be appreciated that in alternative embodiments, more than two chambers may be provided in the container. The chambers 74 and 76 are designed to store substances and/or solutions separately.

In the embodiment shown, any portion of the container 70 is made from a film having at least one of the following: 1) a peel seal layer comprising a blend of a polypropylene random copolymer having a melting temperature greater than 140 ℃, a styrene-ethylene-butylene-styrene block copolymer, and an LLDPE having a melting temperature greater than 115 ℃; 2) a peel seal layer comprising a blend of a polypropylene random copolymer having a melting temperature greater than 140 ℃ and an ethylene-propylene rubber modified polypropylene elastomer; and 3) a barrier layer comprising a caprolactam-free nylon compound.

The container 70 may be made from two sheets of film that are heat sealed, for example, along their edges (80, 82, 84, and 86) to form a permanent seal. In the embodiment shown, two sheets of film are used. The sheet is sealed around the perimeter of the container 70 at edges 80, 82, 84 and 86. Alternatively, the container may be formed by sealing a squeeze tube type film at its open end. In this case, only two opposing edges of the container (e.g., edges 82 and 86) need be sealed. A peelable seal 88 is provided between the film sheets to form chambers 74 and 76. Of course, if additional chambers are provided, additional peelable seals may be provided.

The container 70 and peelable seal 88 may be constructed from a film having a peel seal layer in accordance with embodiments of the present disclosure. The peel seal layer may allow for the creation of both a peel seal and a permanent seal. Thus, permanent side seals 80, 82, 84, and 86 and peelable seals 88 can be created from the same layer of film.

As shown in fig. 5, the container 70 may also include one or more ports 90, 92, 94, and 96. The ports 90, 92, 94, and 96 provide communication with the interior of the chambers 74 and 76, but may be located at any suitable location on the container 70. These ports allow fluid to be added to or removed from chambers 74 and 76. Ports 90, 92, 94, and 96 can also include a membrane (not shown) that is pierced, for example, by a trocar or spike of the administration set. It will be appreciated that one or more of the ports may be provided in the form of a moulded structure having a surface specially adapted to seal with the container, either between the sheets (in which case the port structure is sometimes referred to as a "rigid pull") or directly to the wall. It is also to be appreciated that the port may include a valve or similar occluding structure rather than a simple membrane. Examples of such alternative port structures include the medication port described in U.S. patent No.6,994,699 and the various access ports described in U.S. patent publication No.2005/0083132, both of which are incorporated herein by reference, and

depending on the method used to manufacture the container, a fill port may not be necessary at all. For example, if the container is to be manufactured from a continuous roll of plastic film, the film may be folded longitudinally to create a first permanent seal, the first compartment filled with a solution, then a peelable seal, the second compartment filled, a permanent seal created, and so on.

Examples

The following examples illustrate various embodiments of the present disclosure by way of example and not by way of limitation.

Example 1

A blend containing a copolymer polypropylene, SEBS block copolymer and LLDPE was extruded as a monolayer film. The films after autoclaving were evaluated for sealability as well as some other properties such as clarity (haze), tensile and autoclavability (by observing surface appearance). Comparative testing of films includes the commercial product (CAWITON)PR 4581A-comparative-1) and two films with a composition of 60%/25%/15% of copolymerized polypropylene/SEBS/LLDPE (comparative-2 and comparative-3), which were run with the formulation blends of the present disclosure. Additionally, some peel seal layer blends of the present disclosure were coextruded with other layers to make multilayer films for peel seal performance evaluation.

I. Single layer film

Table 1: comparison of different monolayer films (Peak force, morphology)

Table 2: comparison of different monolayer films (haze, tension, surface appearance)

Note that:

adh.: the adhesion was peeled off.

RBS, RMS, RES: the film tears at the beginning, middle, and end of the seal, respectively.

SMS, SES: the film was stretched in the middle and at the ends of the seal, respectively.

As shown in tables 1 and 2, peel seal blend formulations 31-19, 34-9, 34-10, 36, 8, 36-9, 36-10, and 36-11 were shown to have:

1. wide range of peel-off sealing force: 3 to 30N/15mm

2. The peel force at hot pressing temperature (121 ℃) is low: less than 3N/15mm

3. The permanent sealing force is higher than that of the three comparative formulations

4. The transparency is higher than that of the three comparative formulas

5. Pressable heat property

Table 3: polymeric components of peel seal blends

Multilayer film without gas barrier layer

Formulation 36-9 was used as a peel seal layer in coextruded film vista peel-2 (see table 4). In contrast, the peel seal layers for ZCore-1 and Vista-1 are comparative-2 and comparative-3, respectively.

Table 4: comparison of multilayer films without gas Barrier layer

The peel seal performance of the multilayer film is summarized in table 5 and fig. 6.

Table 5: peel force of the multilayer film of Table 4

Failure mode:

adh.: peel off adhesion

SW: stress whitening

SBS, SMS, SES: the film was stretched at the beginning, middle, and end of the seal, respectively.

RBS, RMS, RES: the film tears at the beginning, middle, and end of the seal, respectively.

Table 5 and fig. 6 show that vista peel-2 has a low peel seal force near the autoclave temperature, possesses a wide peel seal range (up to about 30Nt/15mm), and has the highest permanent seal force.

Multilayer film with gas barrier layer

Formulations 36-9 were used as coextruded films: a peel seal layer of Nylon Peel-2 (see Table 6). In contrast, the peel seal layers for Symredad and NB-1 are comparative-1 and comparative-3, respectively.

Table 6: multilayer film having gas barrier layer

The peel seal performance of the multilayer film is summarized in table 7 and fig. 7.

Table 7: peel force of the multilayer film of Table 6

Note that:

adh.: peel off adhesion

SBS, SES: the film is stretched at the beginning and end of the seal, respectively.

Delam.: layering

Table 7 and fig. 7 show that NP-2 has a low peel seal force around the autoclave temperature, possesses a wide peel seal range (up to about 50N/15mm), and has the highest permanent seal force (at seal temperatures between 147 to 155 ℃).

Example 2

Example 1 provides evidence that formulations comprising a blend of polypropylene copolymer/SEBS/LLDPE provide improved peel seal layers that can be used in many applications. The present research has been directed to improving the toughness of multilayer films by incorporating elastomeric materials and/or lower melting polyolefins into the appropriate layers of the films while maintaining peel seal characteristics. For example, the present formulations include materials incorporated into the peel layer and/or skin layer of various multilayer coextruded films. In addition, PCCE (poly (cyclohexylenedimethylene cyclohexane dicarboxylate), ethylene glycol and acid comonomer) is also used as a tough skin layer in combination with a newly formulated peel-off seal layer. The resulting structure was then tested for peel seal, haze and toughness Using ASTM D3763, "High Speed Performance of Plastics Using load and Displacement Sensors" and/or functional Container drop test.

In the current example, four different peel seal types were tested and compared to the Cawiton reference. Typical formulations of these peel seal layer types are as follows.

Sample 1: the peel seal formulation comprised a blend of approximately 60% PP, 25% SEBS, and 15% PE. The PP used melts at-145 ℃.

Sample 2: the peel seal formulation contained about 60% TOTAL8573 PP, 25% SEBS and 15% LLDPE. TOTAL8573 PP is a softer, slightly lower melting point material (135 ℃ C.) with some added toughness.

Sample 3: the peel seal formulation contained approximately 60% HuntsmanA blend of 43M5A PP, 25% SEBS and 15% LLDPE. Huntsman43M5A is a PP (148 ℃ C.) with a slightly higher melting point, shifting the peel seal curve to a higher temperature to meet the Japanese peel requirements.

Sample 4: the peel seal formulation comprises about 60% HUNTSMAN43M5APP、25％KRATONA blend of G1643 SEBS and 15% LLDPE, the SEBS being more branched and more compatible with PP, and

sample 5: the peel seal formulation comprised a blend of approximately 70% Zelas 7023 (polypropylene-based thermoplastic elastomer) and 30% Huntsman 43M 5A. ZELAS7023 melts at-161 ℃ which allows the stripping requirements of Japan to be easily met.

These peel seal layers are squeezed into several multilayer structures with almost the same peel seal curve results. Fig. 8 shows typical peel seal curves for different sample formulations. Fig. 8 shows that sample 3, sample 4, and sample 5 all provided peel seal characteristics that met the desired properties. These formulations can be used to produce peel seals of about 4N/15mm to about 30N/15mm at temperatures greater than 121 ℃.

Three different versions of the film containing a nylon barrier layer with peel seal layers for sample 3, sample 4 and sample 5 were manufactured and tested. The first film version comprises a structure having sample 3 peel layer and/or PCCE skin layer and is shown as an alternative embodiment of the five-layer structure shown in fig. 2, having the following sequence: skin layer 20/tie layer 22/barrier layer 24/tie layer 26/seal layer 28. Table 8 describes details of the thin film layers. The unit at the end of each layer represents the thickness of that layer.

Table 8: film formulation of the first version

An alternative embodiment of the second film version comprises a structure with sample 3 or sample 4 release layer and, in a two-part structure, a PP/SEBS skin layer. A second version of the film structure comprises maleic anhydride modified homopolymer (ADMER)QF300E and QB510A) and copolymers (ADMER)551A) And (6) bonding layers. All embodiments of these film structures are five-layer structures as shown in fig. 2, having the following sequence: skin layer 20/tie layer 22/barrier layer 24/tie layer 26/seal layer 28. Details of the film layer are set forth in table 9.

Table 9: film formulation of the second version

An alternative embodiment of the third version of the film structure comprises sample 3, sample 4 or sample 5 blended with a sealing layer and a PCCE or PP/SEBS skin layer. In addition, PT-4 contains maleic anhydride modified homopolymer PP blended with SEBS to further toughen the structure. All third versions of the film structure are five-layer structures as shown in fig. 2, in the following order: skin layer 20/tie layer 22/barrier layer 24/tie layer 26/seal layer 28. Details of the film layers are set forth in table 10.

Table 10: third version of film formulation

Table 11 shows the results of the impact test and haze. The results show that films containing version 2 and 3 embodiments with standard EMS FG40NL nylon (TP-4 and N-1 to N-5) have improved impact toughness over commercial Maestro films. The results also show that films containing a PCCE skin and standard EMS FG40NL nylon also have improved impact toughness over Maestro films.

Table 11: impact and haze properties of barrier films

Based on the resulting material compounds and the resulting film structure and measurements, new peel-off sealing compounds and multilayer films were developed. Examples of these peel-off sealing compounds and film structures are given below:

in an alternative embodiment, the peel seal layer film is capable of creating a seal in the multilayer extruded film through a heated die that can be peeled apart without creating residual debris. By varying the temperature, it should be possible to produce a peel force of between 3N/15mm and 30N/15mm on the same peel ply compound in many film configurations and thicknesses. The peel seal should be produced at a temperature greater than 122 ℃. The sealant layer should be capable of being sterilized at 121 ℃ without adversely affecting peel force. An example of such a material is 60% PP random copolymer with a melting temperature greater than 145 ℃, 25% SEBS and 15% LLDPE with a melting temperature greater than 120 ℃. A second example is a blend of 60% to 80% PP-based TPO such as Zelas 7023 with 20% to 40% PP random copolymer having a melting temperature greater than 130 ℃. A third example is a blend of 70% PP random copolymer with a melting temperature greater than 145 ℃, 22.5% SEBS, and 7.5% LLDPE with a melting temperature greater than 120 ℃.

The foregoing embodiments relate to tough and transparent multilayer films containing peel seal layers. The dart impact resistance of the film shows a good correlation with the damage resistance of the container in the product. In one embodiment, the desired dart impact resistance of the multilayer film is greater than 7J/mm. In addition, for a film with a wet surface, it is desirable to maintain the haze below 20%. Finally, CO of such films is desired₂Permeability of less than 200cm³/m²Atmospheric pressure of the day. Examples of such films are TP-4, N-1, N-3, N-4, N-5, PT-1, PT-3 and FGN-2.

Example 3

Caprolactam-free nylon-6, 6/6, 10 copolymer (BM20SBG, from EMS-Grivory) has been considered a good candidate from the extrusion point of view for multilayer barrier films. However, the film based on this structure exhibits drop resistance, dart impact property and gas (O)₂And CO₂) The permeability is significantly inferior to current films containing nylon-6 based barrier layers. Amorphous nylon inherently has significantly improved gas barrier properties. (the minimum blend level that provides sufficient gas barrier resistance can be calculated for a given grade using permeability data and blend rules.) thus, the method of this study blends the appropriate level of amorphous nylon with nylon-6, 6/6, 10 copolymerTo improve impact resistance and gas barrier resistance while maintaining acceptable transparency and UV absorption to meet overall medical regulatory requirements.

Amorphous nylon is blended with nylon-6, 6/6, 10 copolymer and extruded as a single layer to find the best balance of impact resistance, clarity and permeability. Promising blends were identified and incorporated into one or more of the following film structures shown in fig. 9(a) -9 (c). FIG. 9(a) relates to a multilayer thin film structure having the following sequence: skin layer 110/tie layer 120/barrier layer 130/tie layer 140/sealing layer 150. FIG. 9(b) relates to a multilayer thin film structure having the following sequence: skin layer 210/tie layer 220/barrier layer 230/tie layer 240/core layer 250/sealing layer 260. FIG. 9(c) relates to a multilayer thin film structure having the following sequence: skin layer 310/core layer 320/tie layer 330/barrier layer 340/tie layer 350/seal layer 360. The multilayer film is then tested for permeability, physical properties, and/or drop resistance.

Current results

Small-scale process blend testing was performed on existing grades of amorphous nylon, including EMS GRIVORYG21 (Nylon 6I/6T), EMS GRIVORYHB5299 (Nylon MXD6/MXDI copolymer), EMS GRIVORYHB7103 (same) and Dupont SELAR PA (Nylon 6I/6T). Discovery of EMS GRIVORYHB7103 amorphous nylon has the best combination of transparency, permeation resistance and mechanical properties. Then use EMS GRILONBM20SBG nylon-6, 6/6,copolymer 10 and EMS GRIVORYBlends of 50% to 50% and 85% to 15% of HB7103 amorphous nylon made monolayer films. The haze, dart impact, and predicted permeability of these monolayers were then compared to the baseline EMS FG40NL and BM20SBG based on nylon-6. The results of this comparison are given in table 12 below. In table 12, permeability under different relative humidity conditions was calculated based on the rules of the mixture using existing supplier data or measured Baxter data as available data. Past industry experience has also shown that for CO₂Permeability ratio of (A)₂Approximately 4 times higher.

The results in Table 12 show that the best blend is a blend of BM20SBG and HB 710385% to 15%. The dart impact resistance of this blend is about twice that of pure BM20SBG, with the expected permeability being almost equal to FG40NL nylon currently used in Baxter's Maestro film. The 85% to 15% blend has a haze higher than either pure compound, but is still suitable for use in multilayer films. When the blending ratio is changed to 50%, the dart impact property is not improved, but the haze is disadvantageously increased because the single-layer film thus appears hazy. It is possible to optimize the blend ratio, but considering that the monolayer properties of the 85%: 15% blend are satisfactory for current applications. Further testing revealed that adjusting the ratio to 87.5% BM20 SBG/12.5% HB7103 provided slightly better performance.

Table 12: properties of different nylons and nylon blends

^*a as a single layer non-autoclavable heat treatment

b ═ data from EMS-Grivory data sheet and public

A study was completed comparing the 85%: 15% blended nylon with neat BM20SBG or FG40NL in a five layer coextruded film structure. The film structure studied was a five-layer structure as shown in fig. 2, having the following sequence: skin layer 20/tie layer 22/barrier layer 24/tie layer 26/seal layer 28. The structures include PT-3 as described in example 2 and the following structures shown in table 13.

Table 13: film formulations

The results of the haze and impact tests are given in table 14. The haze and impact of CF-1 and CF-2 films containing the 85%: 15% nylon blend are better than NB-1 with pure BM20SBG in a similar structure. CF-2 has better impact resistance than CF-1 because it contains a tie layer based on a polypropylene homopolymer rather than a copolymer, consistent with the trends observed in previous work. The haze of CF-3 is also significantly better than the commercial Maestro containing FG40NL, with almost the same impact. PT-3, which contained FG40NL in a similar structure, had better haze and impact than CF-3.

Table 14: properties of five-layer nylon barrier film with different nylons

Commercial film

The six-layer structure shown in fig. 9(b) and 9(c) exhibits better impact resistance than the five-layer structure. Fig. 3 shows an extruded multilayer film structure sample. The multilayer thin film structure has the following order: skin layer 30/core layer 32/tie layer 34/barrier layer 36/tie layer 38/seal layer 40. Details of the film layer are set forth in table 15.

Table 15: six-layer film formula

Based on the resulting material compounds, thin film structures were produced and the results measured that combining caprolactam-free nylon blends can produce new five and six or more layer nylon barrier film structures that meet the desired container properties. In one embodiment, the desired dart impact resistance for nylon barrier materials used in multilayer films is greater than 4.5J/mm. Meanwhile, the nylon barrier layer should have good heat resistance to heat sealing temperatures greater than 130 ℃ and haze less than 15% when double-sided wetted. Finally, O at about 85% r.h. (relative humidity)₂The permeability should be less than 80cm³/m²Day 25um bar.

The description of the multilayer film incorporating a caprolactam-free nylon barrier layer in an alternative embodiment and the desired properties of the film are as follows:

in one embodiment, the multilayer film is a five-layer film having a caprolactam-free nylon barrier layer as shown in fig. 9 (a). The film may have less than 200cm³/m²CO at natural atmospheric pressure₂Permeability. The film may also include a peel seal between 4N/15mm and 30N/15mm produced by heating at a temperature greater than 122 ℃. The dart impact resistance of the film has been shown to correlate well with the damage resistance of the container in the product. The desired dart impact resistance of the multilayer film can be greater than 6J/mm. In an alternative embodiment, it is desirable that a surface-wetted film maintain a haze of less than 20%. An example of such a film is CF-3.

In another embodiment, the multilayer film is a six layer film having a caprolactam free nylon barrier layer and a tough core as shown in fig. 9(b) -9 (c). The film has CO₂Permeability of less than 200cm³/m²Day atm. The film may further comprise a film produced by heating at a temperature greater than 122 ℃A raw peel seal between 4N/15mm and 30N/15 mm. The dart impact resistance of the film has been shown to correlate well with the damage resistance of the container in the product. The desired dart impact resistance of the multilayer film can be greater than 8J/mm. In an alternative embodiment, it is desirable that a surface-wetted film maintain a haze of less than 20%. Examples of such films are CF-4 to CF-7.

The multilayer film may also comprise raw materials that do not contain substances (e.g., calcium or magnesium stearate, erucamide, other fatty acids, etc.) that can leach and/or precipitate from the film in solutions between pH 2 and 10 to produce particulate matter.

It should be understood that various changes and modifications to the presently preferred embodiments described herein will be apparent to those skilled in the art. Such changes and modifications can be made without departing from the spirit and scope of the present subject matter and without diminishing its intended advantages. It is therefore intended that such changes and modifications be covered by the appended claims.

The claims (modification according to treaty clause 19)

1. A film comprising a barrier layer comprising a caprolactam-free nylon compound comprising a blend of about 75% to about 95% by weight of a polyamide 6, 6/6, 10 copolymer, and about 5% to about 25% by weight of an amorphous polyamide.

2. The film of claim 1, wherein the caprolactam-free nylon compound comprises a blend of about 87.5 weight percent of the polyamide 6, 6/6, 10 copolymer and about 12.5 weight percent of the amorphous polyamide.

3. The film of claim 2 wherein the amorphous polyamide is selected from the group consisting of polyamide MXD6/MXDI copolymer, polyamide 6I/6T copolymer, and combinations thereof.

4. The film of any of the preceding claims, further comprising a skin layer and a peel seal layer adhered to opposite sides of the barrier layer.

5. The film of claim 4 wherein the skin layer comprises a component selected from the group consisting of polypropylene random copolymer, polypropylene homopolymer, nylon, styrene-ethylene-butylene-styrene block copolymer, copolyester ether block copolymer, and combinations thereof.

6. The film of claim 4 wherein the peel seal layer comprises a blend of a polypropylene random copolymer having a melting temperature greater than 140 ℃, a styrene-ethylene-butylene-styrene block copolymer, and a linear low density polyethylene having a melting temperature greater than 115 ℃.

7. The film of any of claims 4 to 6, further comprising at least one tie layer that conforms at least one of the skin layer and the peel seal layer to the barrier layer.

8. The film of claim 7, wherein the tie layer comprises a component selected from the group consisting of maleated linear low density polyethylene, maleated polypropylene homopolymer, maleated polypropylene copolymer, and combinations thereof.

9. The film of any of claims 4 to 8, further comprising a core layer positioned between the skin layer and the barrier layer.

10. The film of any of claims 4 to 8, further comprising a core layer positioned between the barrier layer and the peel seal layer.

11. The film of claim 9 or claim 10, wherein the core layer comprises a component selected from the group consisting of polypropylene homopolymers, propylene-ethylene random copolymers, syndiotactic propylene-ethylene copolymers, polypropylene elastomers, propylene-based elastomers, ethylene-based elastomers, styrene-ethylene-butylene-styrene block copolymers, ethylene-propylene rubber modified polypropylene, and combinations thereof.

12. The film of claim 9 or claim 10, wherein the film has CO₂Permeability of less than 200cm³/m²Atmospheric pressure of the day.

13. The film of claim 9 or claim 10, wherein the film has a dart impact resistance of greater than 6J/mm when measured according to astm d 3763.

14. The film of claim 9 or claim 10, wherein the film has a haze of less than 20% when wetted on a surface.

15. A container, comprising:

a body defined by a film comprising a barrier layer comprising a caprolactam-free nylon compound comprising a blend of about 75% to about 95% by weight of a polyamide 6, 6/6, 10 copolymer, and about 5% to about 25% by weight of an amorphous polyamide.

16. A multi-chamber container comprising:

a body defined by a film comprising at least two chambers separated by a peelable seal, the film comprising a barrier layer comprising a caprolactam-free nylon compound comprising a blend of about 75% to about 95% by weight of a polyamide 6, 6/6, 10 copolymer, and about 5% to about 25% by weight of an amorphous polyamide.

Claims (17)

1. A film comprising a barrier layer comprising a caprolactam-free nylon compound.

2. The film of claim 1, wherein the caprolactam-free nylon compound comprises a blend of about 75% to about 95% by weight of the polyamide 6, 6/6, 10 copolymer, and about 5% to about 25% by weight of the amorphous polyamide.

3. The film of claim 1, wherein the caprolactam-free nylon compound comprises a blend of about 87.5 weight percent of the polyamide 6, 6/6, 10 copolymer and about 12.5 weight percent of the amorphous polyamide.

4. The film of claim 2 or claim 3 wherein the amorphous polyamide is selected from the group consisting of polyamide MXD6/MXDI copolymer, polyamide 6I/6T copolymer, and combinations thereof.

5. The film of claim 1 further comprising a skin layer and a peel seal layer adhered to opposite sides of the barrier layer.

6. The film of claim 5 wherein the skin layer comprises a component selected from the group consisting of polypropylene random copolymer, polypropylene homopolymer, nylon, styrene-ethylene-butylene-styrene block copolymer, copolyester ether block copolymer, and combinations thereof.

7. The film of claim 5 wherein the peel seal layer comprises a blend of a polypropylene random copolymer having a melting temperature greater than 140 ℃, a styrene-ethylene-butylene-styrene block copolymer, and a linear low density polyethylene having a melting temperature greater than 115 ℃.

8. The film of claim 5 further comprising at least one tie layer that attaches at least one of the skin layer and the peel seal layer to the barrier layer.

9. The film of claim 8, wherein the tie layer comprises a component selected from the group consisting of maleated linear low density polyethylene, maleated polypropylene homopolymer, maleated polypropylene copolymer, and combinations thereof.

10. The film of claim 5, further comprising a core layer positioned between the skin layer and the barrier layer.

11. The film of claim 5 further comprising a core layer positioned between the barrier layer and the peel seal layer.

12. The film of claim 10 or claim 11, wherein the core layer comprises a component selected from the group consisting of polypropylene homopolymers, propylene-ethylene random copolymers, syndiotactic propylene-ethylene copolymers, polypropylene elastomers, propylene-based elastomers, ethylene-based elastomers, styrene-ethylene-butylene-styrene block copolymers, ethylene-propylene rubber modified polypropylene, and combinations thereof.

13. The film of claim 10 or claim 11, wherein the film has CO₂Permeability of less than 200cm³/m²Atmospheric pressure of the day.

14. The film of claim 10 or claim 11, wherein the film has a dart impact resistance of greater than 6J/mm when measured according to ASTM D3763.

15. The film of claim 10 or claim 11, wherein the film has a haze of less than 20% when wetted on a surface.

16. A container, comprising:

a body defined by a film comprising a barrier layer comprising a caprolactam-free nylon compound.

17. A multi-chamber container comprising:

a body defined by a film comprising at least two chambers separated by a peelable seal, the film comprising a barrier layer comprising a caprolactam-free nylon compound.