Films and laminates for use in packaging reactive compounds

Abstract

The present present disclosure relates to a laminate film including a water resistant or oxygen resistant base layer, and co-extrusion layer. The coextrusion layer may include a tie layer and a contact layer, and the contact layer may include a polymer such as cyclic olefin copolymer, a polyamide, or an ethylene vinyl alcohol. A total loading of the tie layer may be in the range of 3-9 g/m.sup.2 and wherein a loading of the contact layer is: loading.sub.contact=x*loading.sub.tie, wherein loading.sub.contact is the loading of the contact layer, loading.sub.tie is the total loading of the tie layer, and x is in the range of 0.8 to 3.

Claims

1. An aggressive chemical-resistant laminate film comprising: a base layer, wherein the base layer is one or more of water or oxygen resistant; and a co-extrusion layer, the co-extrusion layer comprising a tie layer and a contact layer, wherein the contact layer comprises a polymer selected from the group consisting of a cyclic olefin copolymer, a polyamide, an ethylene vinyl alcohol, or a combination thereof; wherein a total loading of the tie layer is in the range of 3-9 g/m2 and wherein a loading of the contact layer is: loadingcontact=x*loadingtie, wherein loadingcontact is the loading of the contact layer, loadingtie is the total loading of the tie layer, and x is in the range of 1 to 3, wherein the aggressive chemical-resistant laminate film is resistant to a chemical selected from nicotine, fentanyl, rivastigmine, or lidocaine.

2. The laminate film according to claim 1, wherein x is in the range of 1.33 to 2.75.

3. The laminate film according to claim 1, wherein the tie layer is a multilayered tie layer comprising at least two layers.

4. The laminate film according to claim 3, wherein at least one layer of Flail the multilayered tie layer is made from a material selected from the group consisting of: ethylene methacrylic acid, ethylene acrylic acid, a terpolymer of ethylene, acrylic ester, and maleic anhydride, a terpolymer of ethylene, butyl acrylate, and maleic anhydride, or combinations thereof.

5. The laminate film according to claim 3, wherein a second layer of the multilayered tie layer comprises a material selected from the group consisting of ethylene methacrylic acid, low-density polyethylene, ethylene methyl acrylate, ethylene butyl acrylate, ethylene ethyl acrylate, a terpolymer of ethylene, acrylic ester, and maleic anhydride, a terpolymer of ethylene, butyl acrylate, and maleic anhydride, ethylene acrylic acid, or combinations thereof.

6. The laminate film according to claim 1, wherein the tie layer consists of two layers, a first tie layer and a second tie layer.

7. The laminate film according to claim 6, wherein a loading ratio of the first tie layer to the second tie layer is approximately 1:1.

8. The laminate film according to claim 1, wherein the base layer is selected from the group consisting of a metal foil and a polymer made of a polyamide, silicon, aluminiumoxide coated polyesters and fluoropolymers, or a combination thereof.

Description

BRIEF DESCRIPTION OF THE FIGURES

(1) FIG. 1 is a cross section of an embodiment of a chemical resistant film according to the present disclosure.

(2) FIG. 2 is a cross section of another embodiment of a chemical resistant film according to the present disclosure.

(3) FIG. 3 is a cross section of a laminate according to the present disclosure.

(4) FIG. 4 is a picture illustrating the set-up of the exploration test referred to in example 4.

DETAILED DESCRIPTION

(5) The laminate film and packaging according to the present disclosure is intended for use in packaging highly aggressive substances such as nicotine, rivastigmine, fentanyl or lidocaine, however, the present disclosure should not be limited to these specific substances.

(6) The term “film” or “laminate film” according to the present disclosure contemplates a product comprising a base layer coated with a co-extrusion layer comprising one or more tie layers and a contact layer, or, a base layer laminated with one or more tie layers and a contact layer.

(7) A “packaging” is in the context of the present disclosure intended to mean a final laminate used to pack a substance.

(8) The term “highly aggressive compound” should be understood as a compound which is both very reactive with metals, acids, bases or functional groups such as ketones, alcohols, hydro carbons and/or esters, and/or, volatile but also easily migrates through barriers. Similarly, the term “aggressive chemical resistant film” means a film which when in contact with an aggressive substance does not allow more than 1.5% w/w of nominal content to migrate to the packaging material or that 90-110% w/w of the aggressive chemical substance remains in the product when compared to Barex® as index 100.

(9) The term “oxygen and water resistant” as used in the context of the present disclosure contemplates material for which the oxygen transfer rate (OTR) and/or water vapor transfer rate (WVTR) is no more than 1 preferably no more than 0.1 as also indicated above. The term WVTR may also be referred to as the moisture vapor transfer rate (MVTR). WVTR and MVTR are equivalent.

(10) The term “mechanically wear resistant layer” as used to describe the first outer layer should be understood as a material which is suitable for the manufacture of a flexible packaging. The mechanically wear resistant layer may be chosen from but are not limited to materials such as polyethylene or polyamide based sheets, ortho-phthalaldehyde based sheets, or polyester based sheets or combinations.

(11) Further, the mechanically wear resistant material, i.e. the first outer layer, can be provided as a film that is biaxially oriented to give the packaging a higher seal strength. The term “biaxial oriented” should be understood such that the provided polymer film has been stretched in both a longitudinal and a transverse direction during manufacturing.

(12) The term “exterior side” should be understood in its broadest sense. The term exterior environment is used for defining the direction opposite of the side that is facing the composition or compound to be sealed by the laminate or packaging of the present disclosure. This means that the term exterior environment is independent on whether additional layers are coated, laminated or otherwise attached to the film. Thus, the word is used for specifying in which direction a side of a layer is facing.

(13) The various embodiments of the present disclosure will now be illustrated with references to the figures and examples.

(14) With reference to FIG. 1 a film of the present disclosure will now be described in greater detail. The film, 1, is obtained by providing a base layer, 2, a co-extrusion layer, 5, said co-extrusion layer comprising a tie layer, 3, and a contact layer, 4, which is coated to one side of the base layer, 2, according to the method of the present disclosure and is allowed to cure/adhere thereto. The base layer, 2, and the co-extrusion layer, 5, define the laminate film according to the present disclosure. Consequently, the laminate film comprises a base layer, 2, and a co-extrusion layer 5, wherein the base layer, 2, is intended for facing the exterior environment, and the co-extrusion layer, 5, is intended for facing the composition/compound to be sealed.

(15) The co-extrusion layer may be coated to the base layer of e.g. aluminium, by a co-extrusion system generally known in the art to provide the coextrusion layer coated on the first side of the aluminum base layer. The coextrusion layer may be applied in an amount of maximum 40 g/m.sup.2, preferably maximum 30-40 g/m.sup.2.

(16) The co-extrusion is preferably performed at a temperature of 240-330° C., more preferred 270-300° C. The speed of the application/coating is in the range of 150 to 600 m/min. The equipment suitable for extruding and laminating films and laminates according to the present disclosure may be obtained from Bobst.

(17) In another embodiment the tie layer comprises two layers as illustrated in FIG. 2. The laminate film, 1, is obtained by providing a base layer, 2, then laminating thereto a co-extrusion layer, 5, comprising a two-layered tie layer, 3, comprising a first layer, 3a, and a second layer, 3b, and a contact layer 4. The co-extrusion layer is coated onto one side of the base layer, 2, according to the method of the present disclosure and is allowed to solidify/cure.

(18) In the embodiment illustrated, the tie layer, 3, comprises two layers according to the present disclosure. These layers may be made of EMAA as the first tie layer, 3a, having a loading of 4 g/m.sup.2 and EAA as the second tie layer, 3b, having a loading of maximum 5 g/m.sup.2 so that the total loading of tie layer does not exceed 9 g/m.sup.2. The first layer of EMAA faces the contact layer, 4, made of e.g. polyamide having a loading of 9 to 27 g/m.sup.2, the second layer made of EAA facing the base layer, 2.

(19) The laminate film according to the present disclosure is intended for use as a component of a packaging suitable for sealing a highly aggressive substance. The film may constitute the packaging itself.

(20) To further improve the mechanical wear resistance of the film a first outer layer may be laminated to the base layer side of the film or simply be wrapped around the film to provide a laminate. Hence, in FIG. 3 is illustrated a cross section of an embodiment of a laminate, 12, according to the present disclosure comprising a first outer layer, 21, a base layer, 22, and a co-extrusion layer, 25. The first outer layer, 21 and the base layer side, 22, may be laminated together before, during or after the co-extrusion layer, 25, is applied/coated to the base layer.

(21) The first outer layer, 21, is a mechanically wear resistant layer which adds safety properties to the wrapping ensuring that the wrapping is not inadvertently opened. Hence, the first outer layer can also be seen as a child proof layer meaning that the first outer layer is made of a material and is sealable in such a way that it is difficult for children to open. Additionally, the outer layer may be provided with a second outer layer, 20.

(22) The second outer layer, 20, is typically a paper layer, wherein the paper layer is facing the exterior environment; the exterior facing side of the second outer layer may be printed as desired. The second outer layer, such as a paper layer, is added to improve the stiffness of the packaging in addition to providing a printing platform.

(23) Furthermore, it is within the inventive concept of the present disclosure that an adhesive agent is applied between the first outer layer and the base layer and/or between the first outer layer and the second outer layer. The obtained packaging may then be assembled in such a way that the various layers do not separate during handling, printing and/or packaging of the substance to be packed.

(24) After production, the film, laminate or packaging may be stored as rolls ready for use in further lamination or packaging of a composition to be packed.

(25) In use, the packaging is sealed around the composition to be packed so that the contact layer of the co-extrusion layer faces the interior side and the composition, and, the base layer, first outer layer or second outer layer, as applicable, face the exterior side, so as to create a hollow interior for containing the, composition.

(26) The sealing of the packaging is achieved in such way that the contact layer of the co-extrusion layer is facing the composition so that the remaining part of the packaging is protected by the contact layer of the co-extrusion layer. In this way, the composition is held within the interior of the packaging and will therefore only have direct contact with the contact layer of the co-extrusion layer.

(27) In general, the order in which the different layers of the packaging according to the present disclosure are applied to the base layer is flexible. Hence, the first outer layer may be applied before the co-extrusion layer is added and the other way around. The order depends on which production line is suitable in a specific situation.

(28) According to all aspects of the present disclosure the base layer may be selected from but not limited to a metal foil, preferably aluminum foil, a polymer, such as a polymer made from polyamide, polyvinylidene chloride, silicon or aluminium oxide coated polyesters, and/or fluro polymers, such as commercial Alu foil from e.g. Hydro, or AlOx coated PET films obtainable from e.g. Toray Films Europe, or SiOx coated PET films obtainable from e.g. Celplast under the tradename Ceramis.

(29) According to all aspects of the present disclosure each of the tie layers of the, optionally multi layered, tie layer may be made of a material selected from ethylene methacrylic acid (EMAA), ethylene acrylic acid (EAA), preferably an ethylene acrylic acid having an acrylic acid content of minimum 10 wt-% based on the total weight of the ethylene acrylic acid layer (EEA-high acid) terpolymer of ethylene, acrylic ester and maleic anhydride, preferably ethylene, butyl acrylate, maleic anhydride (t-EBAMA), a terpolymer of ethylene, acrylic ester and maleic anhydride, preferably ethylene, butyl acrylate, maleic anhydride (t-EBAMA), terpolymer of ethylene, methacrylic acid and glycidyl methacrylate, ethylene methyl acrylate (EMA), ethylene butyl acrylate (EBA), ethylene ethyl acrylate (EEA), or low density poly ethylene (LDPE).

(30) Such polymers described above are available as the commercial products Lotader® 3410 sold by Arkema or Nucrel® 0609HSA sold by Dupont®, or Escor™ 6000 sold by ExxonMobil.

(31) According to all aspects of the present disclosure the contact layer may be made of a material selected from cyclic olefin copolymer, a polyamide, or, an ethylene vinyl alcohol or mixtures thereof, such as the commercial products EVAL® C109B sold by Kuraray, Selar PA 3426 R sold by Dupont® or COC 6013M-07, COC 8007F-600, 7010E-600 or 9506F500 sold by Topas® or EVOH obtainable from Nippon Gohsei under the tradename Soarnel®.

(32) According to all aspects of the present disclosure the first outer layer may be made of a material selected from paper, polyethylene or polyamide based sheets, ortho-phthalaldehyde based sheets, or polyester based sheets, or combinations, such as the commercial product F-PAP sold by Flexpet.

(33) The present disclosure will now be illustrated in more details with reference to the following non limiting examples.

(34) RED Calculation

(35) Determination of the HSP values and interaction radius for nicotine, rivastigmine, fentanyl and lidocaine requires that the solubility of the drug is evaluated against at least 16 solvents having a range of polar and hydrogen bonding properties. The methodology of determining HSP values, interaction radius and RED values are described in C. M. Hansen: “Hansen Solubility Parameters, A User's Handbook”, CRC Press, 2007, Second Edition and exemplified in EP 2 895 531.

(36) Typical solvents used to determine the HSP may be but is not limited to the solvents present in table 2.

(37) TABLE-US-00004 TABLE 2 Typical solvents used to determine the HSP of a polymer or substance of interest. Typical solvents used in Determining of HSP of rivagstigmine, lidocaine, fentanyl and nicotine Chemical name Trade Designation or Alternate Name Acetonitrile Acetonitrile Ethylene glycol n-Butyl Ether Butyl CELLOSOLVE ™ Glycol Ether Dibutyl Ether Dibutyl Ether Dimethyl Formamide Dimethyl Formamide Dimethyl Sulfoxide Dimethyl Sulfoxide Methanol Methyl alcohol 2-Butanone Methyl Ethyl Ketone 4-Methyl-2-pentanone Methyl Isobutyl Ketone n-Butyl Acetate n-Butyl Acetate n-Heptane n-Heptane 1-Propanol n-Propyl Alcohol o-Dichlorobenzene 1,2-Dichlorobenzene Tetrahydrofuran Tetrahydrofuran Toluene Methylbenzene Propylene Carbonate Propylene Carbonate Water Water

(38) For assessing the solubility of rivastigmine, lidocaine, fentanyl and nicotine in the solvents an experimental measurement can be performed. The solubility is assessed based on the visual observation of 0.5 g of the chemical substance in a vial with 5 cm.sup.3 solvent at room temperature. The vial is capped with a polyethylene-lined lid and labeled with the solvent loaded. The vials are placed in a vial shaker at low speed at room temperature. After 24 hours, the samples are removed from the vial shaker, and allowed to sit for 30 min before they are visually rated. The rating is performed by giving each solvent a score being 0 for insoluble and 1 for soluble. The numerical ratings are then entered into the HSPiP software program to obtain the HSP (Hansen solubility parameters). R (radius) values for the compound of relevance, e.g. nicotine, rivastigmine, fentanyl and/or lidocaine is inserted, and a report is generated.

(39) The report lists the final parameters and R values calculated for nicotine, rivastigmine, fentanyl and/or lidocaine. The report also lists the solvents used in the evaluation, their HSP values (taken from a database), the rating of the visual observations, and their RED values with a specific polymer of interest. In a similar manner RED values can be calculated for other compounds.

EXAMPLES

(40) Examples 1 and 2 are embodiments of a film according to the present disclosure. The film comprises a base layer connected to a tie layer comprising two layers (a first tie layer and a second tie layer), wherein the first layer of said tie layer is connected to the contact layer. The film according to the present disclosure has an ordered structure of:

(41) Base layer/tie layer 2/tie layer 1/contact layer the latter three layers are coextruded in accordance with the method of the present disclosure to form a co-extrusion layer.

(42) In both examples the co-extrusion layer is co-extrusion coated to the base layer so that the contact layer has a surface intended to be in contact with a composition comprising a compound selected from nicotine, rivastigmine, fentanyl, or lidocaine and wherein such composition may be in the form of a transdermal patch.

Example 1

(43) Example 1 is a film having COC (commercial product Topas® 8007F600) as a contact layer with a loading of 22 g/m.sup.2. The first layer of the multilayered tie layer is a copolymer of ethylene methacrylic acid (Nucrel® 0609HSA) having a loading of 4 g/m.sup.2. The second layer of the multilayered tie layer is a terpolymer of ethylene, butyl acrylate, and maleic anhydride (Lotader® 3410) having a loading of 4 g/m.sup.2. The base layer is aluminium foil. The total loading of the multilayered tie layer and the contact layer being 30 g/m.sup.2.

(44) The film had good mechanical properties cf. the below and was easy to produce.

Example 2

(45) Example 2 is a film having PA (Selar® PA 3426R) as the contact layer with a loading of 8 g/m.sup.2. The first layer of the tie layer is a copolymer of ethylene methacrylic acid (Nucrel® 0609HSA) having a loading of 4 g/m.sup.2. The second layer of the tie layer is a copolymer of ethylene acrylic acid (Escor™ 5110) having a loading of 4 g/m.sup.2. The base layer is aluminium foil. The total loading of the multilayered tie layer and the contact layer being 16 g/m.sup.2.

(46) The film had good mechanical properties cf. the below and was easy to produce.

Example 3

(47) Sample 3 is a film having COC (copolymer—Ehtylenel-norbonene, Commercial product, Topas® 8007F-600) as the contact layer with different loadings as shown below, 22, 22 and 12 respectively.

(48) In a first film, a first layer of the tie layer was a copolymer of ethylene methacrylic acid (Nucrel® 0609HSA) having a loading of 4 g/m.sup.2. The second layer of the tie layer was a copolymer of ethylene acrylic acid (Lotader® 3410) having a loading of 4 g/m.sup.2. The base layer was aluminium foil. In a second and third laminate film only one layer of tie layer was included.

(49) Testing with nicotine as API, the following was found re the laminates' performance.

(50) TABLE-US-00005 TABLE 3 Laminate # Tie 2 Tie 1 Contact Result, API uptake 1 4 4 22 Ok 2 8 22 Ok 3 18 12 Not ok* *Uptake was higher than the specified upper limits.

(51) Alternative commercial COC products include but are not limited to: Topas® 9506F-500, Topas® 7010E-600 (works in terms of API uptake but requires higher welding temperatures than the other two).

Example 4

(52) Similar to the above, different laminate films were made all including outer layers and base layer to mimic a commercial product. The laminate films were produced with varying applications of co-extrudates according to the present disclosure (inv.) and comparative extrudates not part of the present disclosure (comp.), as shown in Table 4.

(53) All laminate films were thus made of PETW36/PE14/AL9 as the outer layers and base layer. The co-extruded layers were composed of;

(54) Tie layer 2: Nucrel® 0609HSA (an ethylene methacrylic acid)

(55) Tie layer 1: Escor® 5110 (an ehtylene acrylic acid)

(56) Contact layer: Selar® PA 3426R (a polyamide)

(57) TABLE-US-00006 TABLE 4 application g/m.sup.2 Tie Tie Total Contact Total Film # layer 2 layer 1 tie layer application 1 1 1 2 8 10 Comp. 2 3 3 6 8 14 Inv. 3 4 4 8 8 16 Inv. 4 7 7 14 12 26 Comp. 5 4 4 8 18 22 Inv. 6 4 4 8 22 30 Inv. 7 4 4 8 24 32 Inv. 8 8 8 16 40 56 Comp.

(58) Thus, films no. 1, 4 and 8 were not according to the present disclosure either because 1) the contact layer was too thick (four times the tie layer), 4) the total tie layer was too thick and the ratio tie/contact outside range, i.e. contact layer too thin; and 8) the total tie layer too thick and also the total loading too high, ratio tie/contact however within range.

(59) Methods

(60) The mechanical properties of the laminate films of table 4 were tested. The following properties were tested: Tear strength Puncture resistance on both sides Sealing strength Lamination strength Exploration test

(61) All tests were made according to industry standards and with some modifications as detailed below:

(62) Tear strength—according to ASTM D1937-14 with no modifications.

(63) Puncture resistance—according to ASTM F1306 with the following modifications: sample diameter 48 mm instead of 34.9 and puncture tool tip diameter 3.0 mm instead of 3.2 mm). The resistance should be at least 50N.

(64) Sealing strength according to DIN 55529 with no modifications.

(65) The sealing strength test was made of three tests:

(66) Trial 1: 150° C., 5 bar pressure, 0.5 seconds

(67) Trial 2: 180° C., 5 bar pressure, 0.5 seconds

(68) Trial 3: 150° C., 5 bar pressure, 0.1 second

(69) Lamination strength according to ASTM D903-98(2010) with the following modifications: Sample width was 15 mm instead of 25 mm, samples were not conditioned to 23° C.+/−1° C., 50% RH+/−2%. Instead all samples were kept at the same place and thus continuously kept under identical conditions. The pull speed was set to 100 mm/min instead of 305 mm/min. The measuring angle was 90° not 180°.

(70) The exploration strength test was made as follows: a four side sealed bag was sealed with parameters 150° C., 0.3 seconds and 3 bar pressure, with a size of 80 mm×90 mm including a 5 mm wide sealing area.

(71) The bag was held between two pieces of iron with a gap of 5 mm (se picture in FIG. 4), and were penetrated with a syringe connected to a pressure device. The bag was then inflated to a pressure of 0.4 bar.

(72) The success criteria for a given laminate is to withhold the pressure for 40 seconds without bursting.

(73) The results of all the tests made is given in table 5.

(74) TABLE-US-00007 TABLE 5 Tear Tear Strength Strength Puncture Puncture Sealing Sealing Sealing Coating (Machine (Cross resistance resistance Lamination strength strength strength loading direction) direction) Front side Sealing side strength #1 #2 #3 Exploration No. (g/m.sup.2) (N) (N) (N) (N) (N/15 mm) (N/15 mm) (N/15 mm) (N/15 mm) test 1 10 0.7 0.4 65.8 58.9 1.5 8.0 7.6 7.6 ok 2 14 0.9 0.5 70.4 62.0 5.1 8.7 9.2 9.3 ok 3 16 0.7 0.5 68.8 65.7 >5 10.8 10.3 9.9 ok 4 26 0.8 0.6 71.1 72.3 4.5 16.4 15.4 12.0 ok 5 22 0.7 0.4 71.6 70.4 2.2 15.7 13.9 14 ok 6 30 1.2 0.5 67.6 67.9 3.7 16.6 16.9 11.9 ok 7 32 0.8 0.5 76.1 73.2 2.4 19.9 17.5 9.5 ok 8 56 1.1 0.9 84.2 88.3 1.7 26.5 23.7 No Seal Fail

DISCUSSION

(75) Tear strength levels from 0.7 to 1.2 indicate that the main influencer for this parameter is the substrate on which the coating is applied, i.e. the base layer and outer layers, since there is no significant increase following coating weight increase.

(76) When looking on puncture resistance samples 1 to 7 showed puncture resistance from 65.8N to 76.1N (front side) and 58.9N to 73.2N (sealing side), while sample 8 with the very thick coating showed an increase to 84.2 and 88.3 respectively. It was surprising to note that even with a loading as thin as 10 g/m.sup.2 (sample 1) mechanical properties on the same level as larger loadings was obtained. However, increasing the total loading of the tie layer to 16 g/m.sup.2 and the total loading to 56 increased the puncture resistance, even though the impact on tear resistance was much less. Hence, on this test it was the upper limits which had an effect of the properties.

(77) Sample 1 showed a lamination strength of 1.5N/15 mm. Since there was only loaded 1 g/m.sup.2 of each tie layer the lowest lamination strength which is too low to be acceptable, app. 2 being the lowest acceptable for the purpose. Sample 2 also had a low loading of tie-layers which is generally lower than those described in the prior art but surprisingly these samples showed laminations strengths on the same level as samples three to seven above the acceptable threshold of app. 2. Sample 8 with the highest total loading could be expected to have the highest laminations strength which surprisingly turned out not to be the case. Without the wish to be bound by any theory it is believed that to be able to apply such high loadings allows the melt to be cooled slightly in the airgap, thereby decreasing lamination strength.

(78) Regarding sealing strength, the results show an increase in sealing strength following an increase in the contact layer part of the co-extrudate until a certain level. Once the layer becomes too thick more energy is needed to seal, and as a result sample 8 does not seal properly under all usual conditions. Sample No. 8 thus has a narrow operation window constraining the machine specifications in the production.

(79) This observation could also be confirmed by the exploration test in which sample No. 8 as the only sample failed. Sample 7 however with a high loading performed well and just as good as sample 1-6 on the sealing test.

(80) In conclusion, from the combined results of the mechanical tests it could be seen that samples 1 and 8 did not fulfill all requirements since the respective lamination strengths were too low. Hence, it appears that there is limits as claimed as regards the relation between tie layers and contact layers. It is also evident from the tests that there is an upper limit to the total layers.

(81) Experiments have shown that the laminate in use in such cases will take up too much API, cf. example 3. Thus, even if sample 4 has satisfactory mechanical properties the update will be too high and the laminate sample cannot be used as intended.