SK6599A3 - Solid-containing polyamide foils - Google Patents

Abstract

Foils consist of (A) 55 to 99 wt % of at least one thermoplastic polyamide; (B) 0.1 to 15 wt % of a mineral filler with a length/diameter (L/D) ratio from 1:5 to 1:100; (C) 0 to 30 wt % of other additives and treatment auxiliary agents. The sum of the percentages by weight of components (A) to (C) always equals 100 %.

Description

The invention relates to polyamide films, a process for their preparation as well as biaxially or monoaxially oriented films obtainable by the process according to the invention. The invention furthermore relates to the use of the films according to the invention, in particular to the use of films as packaging and for the production of multilayer films as well as the multilayer films thus obtained.

BACKGROUND OF THE INVENTION

Polyamides containing mineral fillers are known. Such starting materials are suitable for injection molding and may contain up to 50% filler in the polymer matrix. The polymer matrix exhibits a molecular weight customary for injection molding, with viscosity values of from 100 to 170 ml / g being common.

Polyamide films not only non-oriented, but also mono- or biaxially oriented, as well as their use, are known, for example from DE-A 28 50 182, DE-A 28 50 181 and DE-A 34 26 723. These films may contain solids, as pigments (e.g. TiO ₂ ), nucleating agent (talc, alumina) or antiblocking agent (silica, zeolite, calcium carbonate). These are generally solids in the form of beads or cubes, which can be added in amounts up to 0.1% by weight. (see JP-A 08/73734)

DE-A 41 41 292 discloses biaxially oriented films of a mixture of aliphatic and aromatic polyamides with a modified polyolefin and a pigment, TiO ₂ having a particle size of from 0.01 to 15 µm being added.

Polyamide films (unoriented or biaxially oriented) are often used for packaging food as a barrier film. The polyamide acts as a barrier medium, in particular, against the access of oxygen to the packaged food, while at the same time preventing water leakage from the food (drying of food). Co-extrusion with polyolefins is used to improve the water leakage effect, co-extrusion with EVOH is used to further enhance the oxygen-inhibiting effect. Of course, coextrusion is an expensive process where, due to the necessary adhesive backing layers, at least three extruders for the various components as well as a costly multilayer extrusion head are required.

An example for co-extruded films is JP-A 63/283836.

Another way to improve the protective effect of polyamides is to admix partially aromatic amorphous polyamides of the PA 6I / 6T or PA MXD6 type to standard polyamides (especially PA6). In this case, the amount of added substance in a size arrangement of 10-40% is required. This process is disadvantageous not only because of the high cost, but also because of the considerable changes in the mechanical and optical properties associated therewith and the poor processability of the polyamides (EP-A 358 038).

Biaxially oriented blown films are used in the industrial production of sausage products. In this case, the raw mixture is filled into the cut parts of the blown film, sealed and welded at both ends. By pulling off the foil as a result of the cooking typical of biaxially oriented foils, a tightly filled round sausage is obtained. The film here also serves as an auxiliary product as well as a packaging in which the product is sold only after cutting, so lower permeation is required to improve durability.

Another requirement in addition to improving permeation values includes an improved processing method in the production of blown films, in particular biaxially oriented blown films. Furthermore, a high diameter constant (calibration accuracy) is important, especially in the production of industrially sliced and packaged sausage products, since the manufacturer has to pack a so-called surplus here, in order to maintain the smallest filling weight when varying the diameter.

SUMMARY OF THE INVENTION

It is an object of the present invention to provide polyamide films as well as a process for their preparation, wherein the films should have good permeability to oxygen and water and have a good diameter calibration during processing.

This problem is solved by mono- or biaxially oriented foils having a back-shrinkage value after thermal stabilization of 5 to 30%, which according to the invention consist of

A) 55 to 99% by weight of at least one thermoplastic polyamide

B) 0.1 to 15% by weight of mineral filler with a length / diameter (L / D) ratio of from 1: 5 to 1: 100

C) 0 to 30% by weight of further processing aids and processing aids, wherein the sum of the percentages by weight of components A to C is always 100%.

A preferred embodiment as well as a process for preparing films and their use are set forth in the dependent claims.

Surprisingly, it has been found that the addition of larger amounts of mineral solids, in particular layered silicates in the form of plates with a defined length / diameter ratio, improves the barrier properties of the monofilament to both water and oxygen.

Surprisingly, the addition of these mineral solids can improve the diameter constant in the production of mono- or biaxially oriented films and a lower molecular weight polyamide can be used.

The film component A) comprises 55 to 99, preferably 67 to 99, in particular 80 to 99 and most preferably 85 to 98% by weight of at least one thermoplastic polyamide. Of course, mixtures of the following polyamides may also be used in the films of the invention.

The polyamides of the films according to the invention generally have viscosity values of from 150 to 300 ml / g, preferably 170 to 250 and in particular 185 to 225 ml / g, determined at a 0.5% solution of 96% sulfuric acid at 25 ° C. according to ISO 307.

Preferred are semi-crystalline or amorphous resins, such as those described in U.S. Pat. 2,071,250, 2,071,251, 2,130,523, 2,130,948, 2,241,322, 2,312,966, 2,512,606 and 3,393 210.

Examples are lactam-derived polyamides containing 7 to 13 ring members such as polycaprolactam, polycaprylolactam and polyaurolactam, as well as polyamides which can be prepared by reacting dicarboxylic acids with diamines.

As dicarboxylic acids, alkanedicarboxylic acids having 4 to 12, preferably 6 to 10, carbon atoms and aromatic dicarboxylic acids can be used. Acids include only adipic acid, azelaic acid, sebacic acid, dodecanedicarboxylic acid and terephthalic acid and / or isophthalic acid.

Particularly suitable diamines are the alkanediamine having 6 to 12, in particular 6 to 8, carbon atoms, as well as m-xylylenediamine, di- (4-aminophenyl) methane, di- (4aminocyclohexyl) methane, 2,2-di- (4- aminophenyl) propane or 2,2-di- (4aminocyclohexyl) propane.

Preferred polyamides are polycaprolactam and copolyamide 6/66, as well as copolyamide prepared from caprolactam and terephthalic acid / isophthalic acid (e.g. PA 6 / 6T, PA 6 / 6I).

Particularly preferred are copolyamides 6/66, wherein the proportion of caprolactam monomers is preferably 80 to 95% by weight, based on the copolyamide.

Preference is further given to mixtures of said polyamides, which may consist in particular up to 25% by weight of partially aromatic and / or amorphous polyamides, such as PA6I or PA6 / 6T.

Component B) for polyamide films comprises one mineral filler with a length / diameter ratio (L / D) of from 1: 5 to 1: 100, which is contained in an amount of from 0.1 to 15, preferably from 0.2 to 10, in particular from 0.5 to 5 and most preferably from 1 to 2.5% by weight, based on A) to C).

The length / diameter ratio is preferably from 1:10 to 1:40, in particular from 1:15 to 1:25. This ratio can be determined by electron microscope network images, wherein the diameter and length are determined from at least 50 filler particles.

The average diameter of the mineral solid is preferably 0.1 to 50 µm, in particular 1 to 20 µm.

Preferred mineral solids are platelet-shaped layered silicates, preferably mica (potassium aluminum silicate) is used.

If the SiO ₄ tetraethers are connected to a two-dimensional network system, then the empirical formula for the anion is (Si ₂ O ₅ ² ') _n . The individual layers are crosslinked to each other by means of cations lying between them. More detailed data can be found in FA Cotton, G. Wilkinson, 3rd edition, p. 333, Verlag Chemie, 1974.

The fillers used according to the invention can be treated with a silane of the formula I:

(R _{(CH2) n) a} Si (O - C _m H _{2 m + 1),} wherein _the

R represents: NH ₂ -, CH ₂ -CH-, or HO-, and

V o

m is an integer from 1 to 5, n is an integer from 1 to 10, k is an integer from 1 to 3.

Preferred silanes of formula (I) are those silanes in which R is an amino or epoxy group and n = 1, 2, 3 or 4, m = 1 or 2 if = 1. 2,3-epoxypropyltrimethoxysilane, 3,4-epoxybutyltrimethoxysilane, 2,3epoxypropyltriethoxysilane, 3,4-epoxybutyltriethoxysilane.

The silanes of the formula I used according to the invention are mostly commercially available (e.g. Degussa silanes, pigments of the Information Series No. 75, Degussa AG) and can be prepared in a known manner, for example as described in detail in US 2,930,809.

The processing of the fillers used according to the invention is usually carried out by adding a silane of the formula I, preferably with stirring, to the aqueous filler dispersion, which may also contain emulsifiers. In this case, the alkoxy groups of the silane of the formula I usually react with the OH groups, which are usually present on the surface of the filler, to form Si-O-metal bonds.

The silane may be used in an amount ranging from 0.05 to 5, preferably from 0.1 to 1, in particular from 0.2 to 0.4% by weight, based on the amount of filler.

In addition to the basic components A) and B), the molding composition for the production of polyamide films may contain further additives and processing aids C). Their proportion is usually up to 30% by weight, preferably up to 10% by weight, based on the total weight of components A) to C).

Conventional additives are, for example, oxidation stabilizers and inhibitors, anti-thermal and UV decomposition agents, lubricants and mold release agents, dyes, pigments, plasticizers and flame retardants and rubbers suitable for polyamides (also referred to as impact strength modifiers or elastomeric elastomers) ).

Oxidation inhibitors and heat stabilizers which may be added to the thermoplastic compositions of the invention are copper halides (1), for example chlorides, bromides or iodides, or mixtures thereof, as well as mixtures with sodium or potassium halides or copper halide complexes, for example as triphenyl complex compounds. In addition, sterically hindered phenols may be used, preferably in a concentration of up to 1% by weight based on the total weight of the composition.

Lubricants and molding agents which can be added usually up to 1% by weight, based on the thermoplastic composition, are, for example, long chain fatty acids or derivatives thereof, such as stearic acid, stearyl alcohol, stearic acid alkyl ester, stearic acid amide as well as long chain fatty acid pentaerythol esters. Preferred are calcium stearate, zinc stearate and ethylene bis stearylamide. Antiblocking agents include SiO ₂ , NaAISiO _3, and CaCO ₃ .

In addition, organic dyes such as nigrosine, pigments such as titanium dioxide, cadmium sulfide, cadmium selenide, phthalocyanines, ultramarine blue and carbon black may be added.

Sodium phenylphosphinate, alumina, silica, nylon 22, particularly preferably talc, usually in amounts up to 1% by weight, can be added as nucleating agents.

Examples of plasticizers include dioctyl phthalic acid ester, dibenzyl phthalic acid ester, butybenzyl phthalic acid ester, hydrocarbon oils, N- (n-butyl) -benzenesulfonamide and ortho- and para-tolylethylsulfonamide. The amounts added are usually up to 15% by weight.

The preparation of the molding compositions according to the invention can be carried out in a manner known per se. The preparation is preferably carried out by adding component B), and optionally component C) to the melt of component A).

Conveniently, an extruder is used, for example a single or twin screw extruder or other conventional plasticizer such as Brabender mills or Banbury mills.

Preference is given to preparing a batch (concentrate) of components A) and B), wherein 5 to 50, preferably 15 to 35% by weight of filler B) is incorporated into the polyamide matrix. This concentrate is usually immediately diluted with the polyamide to form a physical mixture so as to achieve the above-described quantitative filler ratios in the polymer matrix. In this process, additives C) can either be incorporated into the batch or added to the polymer melt at a subsequent dilution of the concentrate.

According to the invention, the polyamide films described above are prepared in such a way that a film is produced from components A) to C) by conventional extrusion or blow molding processes. Typically, the film is strengthened by passing the film through rollers or other suitable equipment through a water bath or a tempered air stream.

For the production of mono- or biaxially oriented films, the primary films are usually stretched at least 1.5-fold, preferably at least 2-fold, in at least one direction in the usual manner after consolidation. This can be achieved, for example, by guiding the film through rollers with different rotation speeds. In the case of biaxially oriented foils, the devices used on the sides simultaneously draw the foil in width.

For biaxially oriented blown films, for example, a pressure of from 1 to 3 bar is used in the cavity, the pressure being adjusted to the desired film expansion.

In order to achieve a good and reproducible diameter constant with biaxially oriented blown films, it is advantageous to cool the films, after leaving the melt from the extruder, to a temperature of from 0 to 30 ° C, preferably from 5 to 25 ° C in the first stage. heating the second step to a temperature of from 50 to 95 ° C, preferably from 60 to 90 ° C. The aforementioned temperature parameters are based on the glass transition temperature of the pure component A), i.e. the film is first cooled to a temperature lower than the glass transition temperature and subsequently heated to a temperature higher than the glass transition temperature. However, since this glass transition temperature varies depending on the moisture content of the film, one of ordinary skill in the art uses the above temperature ranges, which can be optimized by routine experimentation for each individual film.

After stretching the films, they can be thermally stabilized in hot air (about 80-160 ° C) or water vapor (60-100 ° C). This is done, for example, by guiding the foils between the rollers through a water bath tempered to an appropriate temperature or a closed tank with a tempered air flow.

Preferred mono- or biaxially oriented films have a heat recovery value of from 5 to 30%, preferably 10 to 20%, after thermal stabilization.

The shrinkage value is usually determined by boiling the film in boiling water for one minute.

The films according to the invention have good permeability properties to water and oxygen. At the same time, in particular biaxially oriented blown films, they exhibit an improved diameter constant. The films according to the invention are therefore suitable as food packaging materials and medical devices. For foodstuffs the most widely used are packaging for different types of sausages (cooked sausages and smoked and imported sausages), as well as for cheese sausage and vacuum packed portioned food packages.

The films according to the invention are further suitable for the preparation of glued or pressed multilayer films comprising at least one layer formed from the films according to the invention.

Multilayer structures with a single food contact polyolefin layer are often chosen for food packaging, for example the PE-adhesion promoter-PA or the PE-adhesion promoter-PA-adhesion promoter ΡΕ. For medical use, PE is replaced with PA for sterilization at 120 ° C. When used for sausage casings, one food contacting PA layer, for example a PA-adhesion promoter-PE-adhesion promoter-PA, is chosen for better adhesion. Another preferred structure is the PA-adhesion promoter-PA, wherein the polyolefin-based adhesion promoter also serves as a water barrier layer. In a multilayer film for use in sausage casings, the non-food contact outer PA-layer is preferably thicker than the inner PA-layer, further it is also preferred that only the outer PA-layer consists of components A) to C).

Suitable polyolefins include homo- and copolymers of α-olefins such as ethylene, propylene or butylene. Polyolefins with acid groups (e.g. maleic anhydride, acrylic acid or methacrylic acid) are usually used as the adhesion promoter between the polyamide and polyolefin layers.

Such multilayer films may be prepared by hot pressing or gluing. In the hot stamping process, at least two films are extruded from the extruder through a multi-layer extruder and joined in this way.

DETAILED DESCRIPTION OF THE INVENTION

Component 1: PA 6 with viscosity number (VZ) 195ml / g (0.5% in 96% H ₂ SO ₄ at 25 ° C according to ISO 307), Ultramid® B35, BASF AG

Component A2: PA 6 with VZ 225 ml / g (Ultramid® B36, BASF AG)

Component A3: PA 6 with VZ 249 ml / g (Ultramid® B4, BASF AG)

Component A4: copolyamide PA 6/66 (85:15) with VZ 246 ml / g (Ultramid® C4, BASF AG)

Component A5: PA 6 with VZ 151 ml / g (Ultramid® B3, BASF AG)

Component A6: 6I6T / DIDT statistical copolyamide of 35% terephthalic acid / 65% isophthalic acid as acid components and 96% 1,6-diamine hexane / 4% Dicycan (4,4-diaminodicyclohexylmethane) as amine components: VZ 120 ml / g (Selar® 3246, DuPont de Nemours Inc.)

Component B1

Preparation of filler concentrate (batch)

30% mica with average particle size (measured with Malvern Particle Size Analyzer) 5pm (d ₅₀ value), average thickness 0.6pm, mean diameter 24 pm, length / diameter ratio L / D = 40 (these values were obtained by calculating ca. 50 particles using electron microscope network images) coated with 0.8% aminosilane (Aspanger® SFG 40, Aspanger AG, -2702 Aspang) were mixed with 70% PA6 (Ultramid® B3, component A5) in a twin screw extruder ( ZSK 30, Werner & Pfleiderer, 280 ° C, 200 rpm, 20 kg / h, PA melt feed, low shear screw combination to reduce particle breakdown), extruded, cooled and granulated.

Component B2: preparation as B1 but using Aspanger® SFG 20, ratio, length / diameter (L / D) = 20, mean diameter (d ₅₀ ) = 12 gm

Component B3: (comparison) preparation as B1, but using calcined kaolin (Polarite® 102 A, Engelhardt Co), particle size d ₅₀ 4 gm, L / D = 2

Component B4: (comparison) preparation as B1, but using calcium carbonate (particle size d ₅₀ 3.5 µm, L / D = 1, Milicarb®, Omya GmbH, Cologne)

Example 1

To 96.5% PA 6 (component A1) was added 3.3% component. B1 (corresponding to 1.0% solids content), and 0.2% finely divided ethylenebis-stearylamide (EBS) and stirred at room temperature in a tumbler. This mixture was molded at a melt temperature of 260 ° C using a blown film extruder (45 mm) (Plamex GmbH, D-Kelberg) to give a primary blown film with a diameter of 30 mm, which was then quenched in a water bath with temperature 9 ° C. The blown film was then heated in a second water bath to 70 ° C and blown to 66 mm (blowing ratio 2.2) with compressed air. The blown film was simultaneously elongated, before and / or after the blow zone, 2.5 times in the longitudinal direction, by varying the speed of movement of the roll pair. The blown film was then heated to 120 ° C in a heat-stabilized heated air dryer as a residence time of 0.8 seconds, and was finally wound up. The residual back shrinkage (so-called boiling shrinkage by immersing the film web for 1 minute in boiling water) was 22% in the length direction and 20% in the transverse direction, the film thickness after stretching being 38 gm.

Examples 2 to 19

As Example 1, but using the material combinations listed in Table 1.

Example 20

96.65% PA 6 (component A1) was mixed with 3.3% component B1 (corresponding to 1.0% solids content), and 0.05% finely divided ethylene bis stearylamide (EBS) and stirred at ambient temperature in drum mixer. This mixture was processed into a blown film at a melt temperature of 260 ° C using a Weber 30 extruder (35 mm diameter) to a 50 µm blown film (measured values see Table 2).

Examples 21 to 31

As Example 20, but using the material combinations listed in Table 2.

The following measurements were taken:

1) tensile strength (lengthwise) according to ISO 527

2) O ₂ permeability in foil tests after 24 hours conditioning at a relative humidity of 100 ° [ml 100 μΓη / m ² bar d] according to ASTM-D 3985-81

3) diameter constant (as a measure of stability of the primary blown film) by measuring the width of the composite oriented final film (= blown film perimeter) of more than 5 m and determining the difference:

d d = d max - d min [mm].

Biaxially oriented films, preparation according to Example 1

Perform processing I Good primary blowing stability, running time 2 hours. without failures Ditto Ditto Ditto Slight variation of primary blowing, running time 2 hours without failures Good primary blowing stability, running time 2 hours. without failure, the secondary hose is slightly cloudy Baby, a little more cloudy as 1 delta D and E E about 00:36 00:44 00:33 0.95 00:42 00:30 00:50 about CM JL Perm. 9.5 9'6 9.7 10.9 11.6 CN cď 7.8 9'6 CM ABOUT Perm. 35 <£> CO ÍO CO ⁴³ 46 . . . 28 26 -CO Tensile strength MPa 220 235 235 225 235 210 195 225 additive SFG 20 SFG 20 SFG 20 SFG 20 SFG 20 SFG 20 SFG 40 Ingredient (B) 3.3% B1 3.3% B1 3.3% B1 1.0% B1 I 10% B1 20% B1 3.3% B2 <Q- B35 B4 B35 B35 B35 B35 B35 PA (A) < A2 A3 < < r- < X " < < UQ. C \ l WHAT M > LO (D r- what

Perform processing as 1 as 5V as 5V I as 5V I Considerable variability in primary blow molding Slight variation in primary blow molding Strong varia- tion during primary blowing, the hose always ruptures after approx. 5 min running time Very good stability in primary blowing, very high transparency Ditto Good primary blow molding stability delta D mm 0.40 H .00 1.20 1.25 1.40 0.55 1.80 0.35 0.47 0.77 ABOUT CM T Perm. about CD * CM_ 11.0 LO 11.0 CM σ> * about Z'6 9.5 12.0 CM ABOUT Perm. 32 47 44 45 43 m CO 45 37 35 49 Tensile strength mpa 220 230 219 210 195 190 195 222 228 232 additive SFG 40 kaolin kaolin CO o o ro O CO o o 05 O SFG 20 I I SFG 20 SFG 20 I m OJ Ό π W □ 5% B2 3.3% B3 10% B3 3.3% B4 10% B3 3.3% B1 l 3.3% B3 3.3% B3 I PA B35 B35 B35 B35 B35 B3 B3 B35 / C35 B4 / C35 B4 / C35 PA (A) < < < < < in < lO < 85% A1 + 15% A4 85% A3 / A4 15% 85% A3 / A4 15% CL CD 10c about 12c 13c • m- 14c LO ω 17c

Perform processing Frequent hose rupture; very good blowing stability at the second water bath at temperature 8O0C Frequent hose rupture; very good blowing stability at the second water bath at temperature 80 ° C delta D 1 mm 0.44 0.82 about CM T Perm. 9'8 RCD <NI ABOUT Perm. 28 38 and Tensile strength , MPa 5> 199 additive SFG 20 I Ingredient (B) and 3.3% B3 I PA B35Selar B35Selar (V) Vd 85% A1 / 15% A6 85% A1 / 15% A6 Pr. WHAT 19c

Non-oriented blown film, preparation according to Example 20

w o c ω D Q. Ο. 1 O CM T 12.0 and b ~ 14.0 14.5 0'6 13.8 14.2 14.0 m xr 12.2 15.2 k'6 CM o ' ω o c CO 2J Q. Φ Ι- Ο. 1 ABOUT o M o M σ> CO Ud CO LO CD CM Lô o in CM iD CM un T xT xr m CD co xr Tensile strength CO b- about 00 about 00 CM CO CM CO xr r- CD b- 00 b- LO b- m CO BB- 00 b- CM b- CO b- additive SFG 20 SFG 20 SFG 20 I I SFG 20 kaolin kaolin n o o CD O O o o CD SFG 20 I SFG 20 I The additive (B) 3.3% B1 3.3% B1 3.3% B1 I I 20% B1 3.3% B3 10% B3 3.3% B4 10% B4 3.3% B3 l 3.3% B3 I < CL B35 B36 M m B35 xT m B35 B35 B35 B35 B35 B4 / C35 B4 / C35 B35 / Selar B35 / Selar component < WITH WHAT < < WHAT < T < < < < < 85% A3 / 15% A4 85% A3 / 15% A4 85% A3 / 15% A6 85% A1 / 15% A6 Example o CM IN" CSL CM CM 23c 24c CO CM 24c 25c 26c by bCM 00 CM 29c o CO 31c

Claims (13)

PATENT CLAIMS Mono or biaxially oriented films having a back-shrinkage value after heat stabilization of 5 to 30%, characterized in that they consist of A) 55 to 99% by weight of polycaprolactam or 6/66 copolyamide or mixtures thereof, which may contain up to 25% by weight of partially aromatic and / or amorphous polyamide, B) 0.1 to 2.5% by weight of mineral filler with a length / diameter (L / D) ratio of from 1: 5 to 1: 100, C) 0 to 30% by weight of further processing aids and processing aids, wherein the sum of the percentages by weight of components A to C is always 100%. The film according to claim 1, characterized in that the mineral filler B) consists of layered silicate-shaped plates. The film according to claim 1 or 2, characterized in that the mineral filler B) is mica. The film according to claims 1 to 3, characterized in that the mineral filler B) has an average diameter of 0.1 to 50 gm. The film according to claims 1 to 4, characterized in that the polyamide A) has a viscosity number (VZ) of from 150 to 300 ml / g (according to ISO 307). A process for the preparation of films according to claims 1 to 5, characterized in that a film is prepared from components A) to C) by means of the usual extrusion or blowing processes. Method according to claim 6, characterized in that the film according to claims 1 to 5 is stretched 1.5 times in at least one direction after consolidation. Method according to claim 6 or 7, characterized in that the film, after leaving the molten state from the extruder, is allowed to cool in the first stage to a temperature of from 0 to 30 ° C and subsequently heated to a temperature of from 50 to 95 in the second stage. C. Method according to claims 6 to 8, characterized in that the film according to claims 1 to 6 is thermally stabilized in hot air or water vapor after stretching. Use of the films according to claims 1 to 5, or obtainable by the process according to claims 6 to 9, as packaging material for foodstuffs and medical devices. Use of the foils according to claim 10 as packaging for cooked sausages and smoked and imported sausages, as well as for cheese sausages. Use of the films according to claims 1 to 5, or obtainable by the process according to claims 6 to 9, for the preparation of pressed or glued multilayer films. Compressed or glued multilayer films comprising at least one film layer according to claims 1 to 5.