Polymer film comprising a copolyamide of a diamine, a dimer acid and a lactam

Abstract

The present invention relates to a polymer film (P), comprising at least one copolyamide, wherein the copolyamide has been prepared by polymerizing at least one lactam (A) and a monomer mixture (M). The present invention further relates to a process for producing the polymer film (P) and to the use of the polymer film (P) as packaging film.

Claims

1. A polymer film, comprising: a copolyamide, which is prepared by polymerizing components: (A) from 15% to 84% by weight of at least one lactam, (B) from 16% to 85% by weight of a monomer mixture consisting of components: (B1) a C.sub.32-C.sub.40 dimer acid; and (B2) a C.sub.4-C.sub.12 diamine, and (B3) optionally a C.sub.4-C.sub.20 diacid; wherein percentages by weight of the components (A) and (B) are based on a total weight of the components (A) and (B), and if (B3) is not present in component (B), component (B) consists of 45 to 55 mol % of component (B1) and 45 to 55 mol % of component (B2), based in each case on the total molar amount of component (B), or if (B3) is present in component (B), component (B) consists of 13 to 52.9 mol % of component (B1), 47 to 53 mol % of component (B2), and 0.1 to 13 mol % of component (B3), based in each case on the total molar amount of component (B); wherein the copolyamide has a viscosity number in the range from 160 to 290 mL/g, determined in a 0.5% by weight solution of the copolyamide in a mixture of phenol/o-dichlorobenzene in a weight ratio of 1:1.

2. The polymer film according to claim 1, wherein the component (A) is selected from the group consisting of 3-aminopropanolactam, 4-aminobutanolactam, 5-aminopentanolactam, 6-aminohexanolactam, 7-aminoheptanolactam, 8-aminooctanolactam, 9-aminononanolactam, 10-aminodecanolactam, 11-aminoundecanolactam and 12-aminododecanolactam.

3. The polymer film according to claim 1, wherein the component (B) consists of from 45 to 55 mol % of the component (B1) and from 45 to 55 mol % of the component (B2), based on a total molar amount of the component (B).

4. The polymer film according to claim 1, wherein the component (B2) is selected from the group consisting of tetramethylenediamine, pentamethylenediamine, hexamethylenediamine, decamethylenediamine and dodecamethylenediamine.

5. The polymer film according to claim 1, wherein the component (B1) is prepared from one or more unsaturated fatty acids selected from the group consisting of an unsaturated C.sub.16 fatty acid, an unsaturated C.sub.18 fatty acid, and an unsaturated C.sub.20 fatty acid.

6. The polymer film according to claim 1, wherein the copolyamide has a glass transition temperature ranging from 20 to 50° C.

7. The polymer film according to claim 1, wherein the copolyamide has a melting temperature ranging from 150 to 210° C.

8. The polymer film according to claim 1, comprising: a first layer comprising the copolyamide, and an additional layer, wherein the additional layer comprises an additional polymer selected from the group consisting of a polyolefin, a poly(ethylene-vinyl alcohol), a poly(ethylene-vinyl acetate), a polyethylene terephthalate, a polyvinylidene chloride and a maleic anhydride-grafted polyolefin.

9. The polymer film according to claim 1, produced in a casting process, in a blowing process, in a biaxially oriented polyamide film process, or in multifilm blowing process.

10. The polymer film according to claim 1, wherein the polymer film has a thickness ranging from 0.1 μm to 1 mm.

11. The polymer film according to claim 1, wherein the copolyamide is a random copolymer.

12. A process for producing the polymer film according to claim 1, comprising: preparing the copolyamide in a molten form in a first extruder, extruding the copolyamide in the molten form out of the first extruder through a die to obtain a film of the copolyamide in the molten form, and cooling the film of the copolyamide in the molten form, with solidification of the copolyamide to obtain the polymer film.

13. A packaging film, comprising the polymer film according to claim 1.

Description

EXAMPLES

(1) The properties of the polymer films (P) were determined as follows:

(2) The viscosity number of copolyamides comprising units derived from a C.sub.32-C.sub.40 dimer acid was determined in a 0.5% by weight solution of phenol/o-dichlorobenzene in a weight ratio of 1:1 at 25° C.

(3) The viscosity number of copolyamides and polyimides that do not comprise any units derived from a C.sub.32-C.sub.40 dimer acid was determined in a 0.5% by weight solution in 96% by weight sulfuric acid at 25° C. according to EN ISO 307: 2007+Amd 1: 2013.

(4) The glass transition temperatures and melting temperatures were determined according to ISO 11357-1: 2009, ISO 11357-2: 2013 and ISO 11357-3: 2011. For this purpose, two heating runs were conducted and the glass transition and melting temperatures were ascertained from the second heating run.

(5) The densities of the polyamides were determined by the gas pycnometer method according to EN ISO 1183-3: 1999.

(6) For determination of the proportion of polyamide-6,36 in the copolyamide, the copolyamide was hydrolyzed in dilute hydrochloric acid (20%). This protonates the units derived from hexamethylenediamine, with the chloride ion from the hydrochloric acid forming the counterion. By means of ion exchanger, this chloride ion was then exchanged for a hydroxide ion with release of hexamethylenediamine. By titration with 0.1 molar hydrochloric acid, the hexamethylenediamine concentration is then determined, from which the proportion of polyamide-6,36 in the copolyamide can be determined.

(7) Tear propagation resistance is determined according to Elmendorf, DIN ISO 6383-2: 2004 in extrusion direction (MD) and at right angles thereto (TD). The films were conditioned under standard climatic conditions for non-tropical countries according to DIN EN ISO 291: 2008.

(8) Modulus of elasticity is determined according to ISO 527-3: 1995.

(9) The impact resistance of the polymer film (P) was determined according to DIN ISO 7765-2: 1994 with 5 specimens at a relative air humidity of 0%, with reporting of the puncture energy in the present context.

(10) The following polymers were used:

(11) Polyamides

(12) P-1 nylon-6 from BASF SE®, sold under the Ultramid B40L brand name, with a viscosity number of 250 mL/g, a glass transition temperature of 57° C., a melting temperature of 220° C. and a density of 1.153 g/mL. P-2 nylon-6 from BASF SE®, sold under the Ultramid B33L brand name, with a viscosity number of 195 mL/g, a glass transition temperature of 56° C., a melting temperature of 220° C. and a density of 1.145 g/mL. P-3 copolymer of nylon-6 and nylon-6,6 (PA 6/6.6) from BASF SE®, sold under the Ultramid C40L brand name, with a viscosity number of 250 mL/g, a glass transition temperature of 53° C., a melting temperature of 190° C. and a density of 1.143 g/mL. P-4 copolymer of nylon-6 and nylon-6,6 (PA 6/6.6) from BASF SE®, sold under the Ultramid C33L brand name, with a viscosity number of 195 mL/g, a glass transition temperature of 55° C., a melting temperature of 196° C. and a density of 1.144 g/mL.
Copolyamides with Dimer Acid: C-1 A copolyamide of nylon-6 and polyamide-6,36, prepared by the following method: 900 kg of caprolactam (component (A)), 83.5 kg of Pripol 1009 from Croda (C.sub.36 dimer acid, hydrogenated, component (B1)), 19.9 kg of 85% by weight hexamethylenediamine solution (component (B2)) in water, 100 g of Polyapp 2557-CTW antifoam reagent composed of polymethylsiloxane from Polystell do Brazil and 100 kg of water were mixed in a 1930 L tank and blanketed with nitrogen. The outside temperature of the tank was heated to 290° C. and the mixture present in the tank was stirred at this temperature for 11 hours. In the first 7 h the mixture was stirred at elevated pressure, in the next 4 hours under reduced pressure, during which the water formed was distilled off. The copolyamide thus obtained was then discharged from the tank, extruded and pelletized. After the pellets of the copolyamide obtained had been extracted with water at 95° C. for 4×6 hours, the copolyamide was dried at 90 to 140° C. in a nitrogen stream for 10 hours. The viscosity number was 246 mL/g, the glass transition temperature was 49° C. and the melting temperature was 211° C. The proportion of polyamide-6,36 in the copolyamide, based on the total weight of the copolyamide, was 10.5% by weight; the density was 1.116 g/mL. C-2 A copolyamide of nylon-6 and polyamide-6,36, prepared by the following method: 1039 kg of caprolactam (component (A)), 216 kg of Pripol 1009 from Croda (C.sub.36 dimer acid, hydrogenated, component (B1)), 51.7 kg of 85% by weight hexamethylenediamine solution (component (B2)) in water, 100 g of Polyapp 2557-CTW antifoam reagent from Polystell do Brazil and 142 kg of water were mixed in a 1930 L tank and blanketed with nitrogen. The outside temperature of the tank was heated to 290° C. and the mixture was stirred at this temperature for 11 hours. In the first 7 h the mixture was stirred at elevated pressure, in the next 4 hours under reduced pressure, during which the water formed was distilled off. The copolyamide obtained was discharged from the tank, extruded and pelletized. The pellets of the copolyamide obtained were extracted with water at 95° C. for 4×6 hours and then dried at 90 to 140° C. in a nitrogen stream for 10 hours. The copolyamide obtained had a viscosity number of 244 mL/g, a glass transition temperature of 44° C. and a melting temperature of 203° C. The proportion of polyamide-6,36 in the copolyamide, based on the total weight of the copolyamide, was 20.8% by weight; the density was 1.095 g/mL. C-3 A copolyamide of nylon-6 and polyamide-6,36, prepared by the following method: 932 kg of caprolactam (component (A)), 323.2 kg of Pripol 1009 from Croda (C.sub.36 dimer acid, hydrogenated, component (B1)), 77.84 kg of 85% by weight hexamethylenediamine solution (component (B2)) in water and 153 kg of water were mixed in a 1930 L tank and blanketed with nitrogen. The outside temperature of the tank was heated to 290° C. and the mixture was stirred at this temperature for 11 hours. In the first 7 h the mixture was stirred at elevated pressure, in the next 4 hours under reduced pressure, during which water formed was distilled off. The copolyamide obtained was discharged from the tank, extruded and pelletized. The pellets of the copolyamide obtained were extracted with water at 95° C. for 4×6 hours and then dried at 90 to 140° C. in a nitrogen stream for 10 hours. The copolyamide obtained had a viscosity number of 259 mL/g, a glass transition temperature of 38° C. and a melting temperature of 188° C. The proportion of polyamide-6,36 in the copolyamide, based on the total weight of the copolyamide, was 30.3% by weight; the density was 1.076 g/mL. C-4 A copolyamide of nylon-6 and polyamide-6,36, prepared by the following method: 932 kg of caprolactam (component (A)), 322 kg of Empol 1061 from BASF SE (C.sub.36 dimer acid, unhydrogenated, component (B1)), 77.84 kg of 85% by weight hexamethylenediamine solution (component (B2)) in water and 153 kg of water were mixed in a 1930 L tank and blanketed with nitrogen. The outside temperature of the tank was heated to 290° C. and the mixture was stirred at this temperature for 11 hours. In the first 7 h the mixture was stirred at elevated pressure, in the next 4 hours under reduced pressure, during which water formed was distilled off. The copolyamide obtained was discharged from the tank, extruded and pelletized. The pellets of the copolyamide obtained were extracted with water at 95° C. for 4×6 hours and then dried at 90 to 140° C. in a nitrogen stream for 10 hours. The copolyamide obtained had a viscosity number of 212 mL/g, a glass transition temperature of 38° C. and a melting temperature of 187° C. The proportion of polyamide-6,36 in the copolyamide, based on the total weight of the copolyamide, was 28.9% by weight; the density was 1.076 g/mL.
Further Polymer (FP) FP-1 Low-density polyethylene (LDPE) from LyondellBasell®, sold under the Lupolen 2420 F brand name with an MFR (melt flow rate) (190° C./2.16 kg) of 0.75 g/10 min. FP-2 Low-density polyethylene (LDPE) from LyondellBasell®, sold under the Lupolen 3020 K brand name with an MFR (melt flow rate) (190° C./2.16 kg) of 4 g/10 min. FP-3 Anhydride-modified linear low-density polyethylene (LLDPE) from DuPont®, sold under the Bynel 4104 brand name with an MFR (melt flow rate) (190° C./2.16 kg) of 1.1 g/10 min. FP-4 Anhydride-modified linear low-density polyethylene (LLDPE) from DuPont®, sold under the Bynel 4105 brand name with an MFR (melt flow rate) (190° C./2.16 kg) of 4 g/10 min. FP-5 A poly(ethyl-vinyl alcohol) (EVOH) from Kuraray®, sold under the EVAL F171B brand name with an MFR (melt flow rate) (210° C./2.16 kg) of 1.8 g/10 min and an ethylene content of 32 mol %. FP-6 A poly(ethyl-vinyl alcohol) (EVOH) from Kuraray®, sold under the EVAL L171B brand name with an MFR (melt flow rate) (210° C./2.16 kg) of 4 g/10 min and an ethylene content of 27 mol %.
Production of Monofilms by a Casting Process

(13) For production of monofilms, a 7-layer cast film system from Collin® with a die head width of 800 mm was used. Thus, 7 extruders were used. 6 of the extruders had a diameter of 30 mm (extruders B, C, D, E, F, G); one extruder had a diameter of 45 mm (extruder A). Each of the 7 extruders were loaded with the same component. The melt from extruder A was in contact with the casting roll; the melt from extruder G was the furthest removed therefrom. The sequence of the layers was A, B, C, D, E, F, G. The polymer films produced had a thickness of 100 μm and the layers had a layer thickness of 15/14/14/14/14/14/15 μm. The components used and the results of the measurement of the tear propagation resistance, modulus of elasticity and puncture resistance are specified in table 1. The percentages by weight of component (B) specified in table 1 are understood to mean the percentages by weight of units derived from component (B) (polyamide-6,36 units) in the copolyamide, based on the total weight of the copolyamide.

(14) TABLE-US-00001 TABLE 1 V1 V2 V3 B4 B5 Component P-2 P-4 C-1 C-2 C-3 Component (B) [% by wt.] — — 10.5 20.8 30.3 Tear [mN] 2337 2601 3076 6329 7706 propagation (8 N (8 N (8 N (32 N (32 N resistance pendulum) pendulum) pendulum) pendulum) pendulum) (MD) Tear [mN] 2046 3337 2734 6087 7588 propagation (8 N (8 N (8 N (8 N (8 N resistance (TD) pendulum) pendulum) pendulum) pendulum) pendulum) Modulus of [MPa] 758 439 713 621 514 elasticity (MD) Modulus of [MPa] 756 469 684 621 365 elasticity (TD)
Production of Multilayer Films by a Casting Process

(15) Multilayer films comprising three different polymers were produced in the above-described 7-layer cast film system from Collin®. The multilayer films obtained had a thickness of 100 μm and the layers had a layer thickness of 15/14/14/14/14/14/15 μm. The extruders of the cast film system were charged with the components in accordance with the makeup of the multilayer films specified in table 2. The percentages by weight of component (B) specified in table 2 are understood to mean the percentages by weight of units derived from component (B) (polyamide-6,36 units) in the copolyamide, based on the total weight of the copolyamide. Table 2 also states the properties of the multilayer film produced.

(16) TABLE-US-00002 TABLE 2 V6 V7 V8 B9 B10 Makeup FP-2 // FP-4 // FP-2 // FP-4 // FP-2 // FP-4 // FP-2 // FP-4 // FP-2 // FP-4 // P-2 // P-2 // P-2 // P-4 // P-4 // P-4 // C-1 // C-1 // C-1 // C-2 // C-2 // C-2 // C-3 // C-3 // C-3 // FP-4 // FP-2 FP-4 // FP-2 FP-4 // FP-2 FP-4 // FP-2 FP-4 // FP-2 Component (B) [% by wt.] — — 10.5 20.8 30.3 Tear [mN] 1293 1850 1702 2841 5874 propagation (8 N pendulum) (8 N pendulum) (8 N pendulum) (8 N pendulum) (8 N pendulum) resistance (MD) Tear [mN] 1438 1998 2131 3709 15856 propagation (8 N pendulum) (8 N pendulum) (8 N pendulum) (8 N pendulum) (32 N pendulum) resistance (TD) Puncture energy [J] 0.3 0.3 0.3 1.4 2.1 Modulus of [MPa] 437 347 431 408 353 elasticity (MD) Modulus of [MPa] 432 344 442 403 328 elasticity (TD)
Production of Multilayer Films by a Casting Process

(17) Multilayer films comprising five different polymers were produced in the above-described 7-layer cast film system from Collin®. The multilayer films obtained had a thickness of 100 μm and the layers had a layer thickness of 15/14/14/14/14/14/15 μm. The extruders of the cast film system were charged with the components in accordance with the makeup of the multilayer films specified in table 3. The percentages by weight of component (B) specified in table 3 are understood to mean the percentages by weight of units derived from component (B) (polyamide-6,36 units) in the copolyamide, based on the total weight of the copolyamide. Table 3 also states the properties of the multilayer film produced.

(18) TABLE-US-00003 TABLE 3 V11 V12 V13 B14 B15 Makeup FP-2 // FP-4 // FP-2 // FP-4 // FP-2 // FP-4 // FP-2 // FP-4 // FP-2 // FP-4 // P-2 // FP-6 // P-2 P-4 // FP-6 // P-4 // C-1 // FP-6 // C-1 // C-2 // FP-6 // C-2 // C-3 // FP-6 // C-3 // // FP-4 // FP-2 FP-4 // FP-2 FP-4 // FP-2 FP-4 // FP-2 FP-4 // FP-2 Component (B) [% by wt.] — — 10.5 20.8 30.3 Tear propagation [mN] 3649 4344 4257 13206 11311 resistance (MD) (8 N pendulum) (8 N pendulum) (8 N pendulum) (32 N pendulum) (32 N pendulum) Tear propagation [mN] 3909 8812 6667 17953 14408 resistance (TD) (8 N pendulum) (32 N pendulum) (32 N pendulum) (8 N pendulum) (32 N pendulum) Modulus of [MPa] 717 629 723 698 628 elasticity (MD) Modulus of [MPa] 721 650 721 679 681 elasticity (TD)
Production of Monofilms by the Blowing Process

(19) Monofilms were produced in a 7-layer blown film system from Collin® having a die head diameter of 180 mm. Of the 7 extruders, 6 had a diameter of 30 mm (extruders B, C, D, E, F, G) and one a diameter of 45 mm (extruder A). The melt from extruder was on the inside of the bubble; the melt from extruder G was on the outside. The sequence of the layers, from the inside outward, was A, B, C, D, E, F, G. The monofilms produced had a thickness of 100 μm and the layers had a layer thickness of 15/14/14/14/14/14/15 μm in the monofilms. All the extruders were loaded with the same component. The films were slit before they were wound up.

(20) The components used and the properties of the monomaterial films are specified in table 4. The percentages by weight of component (B) specified in table 4 are understood to mean the percentages by weight of units derived from component (B) (polyamide-6,36 units) in the copolyamide, based on the total weight of the copolyamide.

(21) TABLE-US-00004 TABLE 4 V16 V17 V18 B19 B20 Component P-1 P-3 C-1 C-2 C-3 Component (B) [% by — — 10.5 20.8 30.3 wt.] Tear [mN] 1913 4783 3083 3804 9548 propagation (8 N (8 N (8 N (32 N (32 N resistance (MD) pendulum) pendulum) pendulum) pendulum) pendulum) Tear [mN] 1823 5325 2909 5767 22287 propagation (8 N (8 N (8 N (8 N (8 N resistance (TD) pendulum) pendulum) pendulum) pendulum) pendulum) Modulus of [MPa] 635 411 536 412 329 elasticity (MD) Modulus of [MPa] 656 410 510 446 356 elasticity (TD)
Production of Multilayer Films in a Blowing Process

(22) Multilayer films comprising three different materials were produced in a 7-layer blown film system from Collin® with a die head diameter of 180 mm. Of the 7 extruders, 6 had a diameter of 30 mm and one a diameter of 45 mm. The multilayer films obtained had a thickness of 100 μm and the layers had a layer thickness of 15/14/14/14/14/15 μm. The extruders of the blown film system were charged with the components in accordance with the makeup of the multilayer films specified in table 5. Table 5 also states the properties of the multilayer films produced. The percentages by weight of component (B) specified in table 5 are understood to mean the percentages by weight of units derived from component (B) (polyamide-6,36 units) in the copolyamide, based on the total weight of the copolyamide.

(23) TABLE-US-00005 TABLE 5 V21 V22 V23 B24 B25 Makeup FP-1 // FP-3 // FP-1 // FP-3 // FP-1 // FP-3 // FP-1 // FP-3 // FP-1 // FP-3 // P-1 // P-1 // P-1 // P-3 // P-3 // P-3 // C-1 // C-1 // C-1 // C-2 // C-2 // C-2 // C-3 // C-3 // C-3 // FP-3 // FP-1 FP-3 // FP-1 FP-3 // FP-1 FP-3 // FP-1 FP-3 // FP-1 Component (B) [% by — — 10.5 20.8 30.3 wt.] Tear propagation [mN] 1461 2826 1950 3109 5181 resistance (MD) (8 N pendulum) (8 N pendulum) (8 N pendulum) (8 N pendulum) (8 N pendulum) Tear propagation [mN] 1461 2824 2122 3468 4318 resistance (TD) (8 N pendulum) (8 N pendulum) (8 N pendulum) (8 N pendulum) (8 N pendulum) Puncture energy [J] 1.3 0.6 1.3 3.7 4.0 Modulus of [MPa] 377 312 321 316 280 elasticity (MD) Modulus of [MPa] 391 307 356 326 307 elasticity (TD)
Production of Multilayer Films in a Blowing Process

(24) Multilayer films comprising five different polymers were produced in a 7-layer blown film system from Collin® with a die head diameter of 180 mm. Of the 7 extruders, 6 had a diameter of 30 mm and one a diameter of 45 mm. The multilayer films obtained had a thickness of 100 μm and the layers had a layer thickness of 15/14/14/14/14/15 μm. The extruders of the blown film system were charged with the components in accordance with the makeup of the multilayer films specified in table 6. Table 6 also states the properties of the multilayer films produced. The percentages by weight of component (B) specified in table 6 are understood to mean the percentages by weight of units derived from component (B) (polyamide-6,36 units) in the copolyamide, based on the total weight of the copolyamide.

(25) TABLE-US-00006 TABLE 6 V26 V27 V28 B29 B30 Makeup FP-1 // FP-3 // FP-1 // FP-3 // FP-1 // FP-3 // FP-1 // FP-3 // FP-1 // FP-3 // P-1 // FP-5 // P-1 // P-3 // FP-5 // P-3 // C-1 // FP-5 // C-1 // C-2 // FP-5 // C-2 // C-3 // FP-5 // C-3 // FP-3 // FP-1 FP-3 // FP-1 FP-3 // FP-1 FP-3 // FP-1 FP-3 // FP-1 Component (B) [% by — — 10.5 20.8 30.3 wt.] Tear propagation [mN] 1975 6401 1875 6194 10042 resistance (MD) (8 N pendulum) (32 N pendulum) (8 N pendulum) (32 N pendulum) (32 N pendulum) Tear propagation [mN] 2325 8062 1975 9637 13530 resistance (TD) (8 N pendulum) (8 N pendulum) (8 N pendulum) (8 N pendulum) (8 N pendulum) Puncture energy [J] 0.7 0.8 1.2 1.2 0.9 Modulus of [MPa] 814 709 878 778 714 elasticity (MD) Modulus of [MPa] 793 710 421 672 593 elasticity (TD)
Production of Monofilms in the Blowing Process

(26) Monofilms were produced in a 7-layer blown film system from Collin® with a die head diameter of 180 mm. Of the 7 extruders, 6 had a diameter of 30 mm and one a diameter of 45 mm. The monomaterial films produced had a thickness of 100 μm and the layers had a layer thickness of 15/14/14/14/14/14/15 μm. All the extruders were loaded with the same component.

(27) The components used and the properties of the monofilms are specified in table 7. The percentages by weight of component (B) specified in table 7 are understood to mean the percentages by weight of units derived from component (B) (polyamide-6,36 units) in the copolyamide, based on the total weight of the copolyamide.

(28) TABLE-US-00007 TABLE 7 V31 V32 B33 Component P-1 P-3 C-4 Component (B) [% by — — 28.9 wt.] Tear propagation [mN] 1910 4408 8654 resistance (MD) (8N pendulum) (8N (32N pendulum) pendulum) Tear propagation [mN] 1736 4057 11436 resistance (TD) (8N pendulum) (8N (32N pendulum) pendulum) Modulus of elasticity [MPa] 666 484 297 (MD) Modulus of elasticity [MPa] 678 457 299 (TD)
Production of Multilayer Films in the Blowing Process

(29) Multilayer films were produced in a 7-layer blown film system from Collin® with a die head diameter of 180 mm. Of the 7 extruders, 6 had a diameter of 30 mm and one a diameter of 45 mm. The monomaterial films produced had a thickness of 100 μm and the layers had a layer thickness of 15/14/14/14/14/14/15 μm. All the extruders were loaded with the same component.

(30) The components used and the properties of the monomaterial films are specified in table 8. The percentages by weight of component (B) specified in table 8 are understood to mean the percentages by weight of units derived from component (B) (polyamide-6,36 units) in the copolyamide, based on the total weight of the copolyamide.

(31) TABLE-US-00008 TABLE 8 V34 V35 B36 Makeup FP-1 // FP-3 // FP-1 // FP-3 // FP-1 // FP-3 // P-1 // FP-5 // P-1 // P-3 // FP-5 // P-3 // C-4 // FP-5 // C-4 // FP-3 // FP-1 FP-3 // FP-1 FP-3 // FP-1 Component (B) [% by — — 28.9 wt.] Tear propagation [mN] 1932 3079 15149 resistance (MD) (8N pendulum) (32N pendulum) (32N pendulum) Tear propagation [mN] 2276 6124 10110 resistance (TD) (8N pendulum) (8N pendulum) (32N pendulum) Modulus of [MPa] 990 824 746 elasticity (MD) Modulus of [MPa] 966 784 728 elasticity (TD)

(32) The above examples show that the copolyamide of the invention can significantly increase the tear propagation resistance of the polymer films (P) both in extrusion direction and at right angles thereto. The modulus of elasticity and puncture resistance of the polymer films (P) of the invention are also within a range acceptable for practical use, and so the polymer films (P) of the invention have advantageous properties overall, especially as packaging films.