MULTILAYER FILM

Abstract

Multilayer film of at least three layers, one core layer and at least one sealing layer wherein the sealing layer comprises a linear low density polyethylene having a density in the range of 0.915 to 0.925 g/cm.sup.3, and the core layer comprises a propylene 1-hexene copolymer, said copolymer has an 1-hexene content in the range of 2.0 to 5.0 wt.-% and a xylene soluble fraction in the range of 0.3 to 15.0 wt.-%.

Claims

1. Multilayer film comprising at least three layers, one 1.sup.st sealing layer (SL1), one core layer (CL) and one outer layer (OL), the stacking order of the at least three layers is (SL1)/(CL)/(OL), wherein: (a) the 1.sup.st sealing layer (SL1) comprises at least 90 wt. %, based on the total weight of the 1.sup.st sealing layer (SL1), of a 1.sup.st base polymer composition (BC1), said 1.sup.st base polymer composition (BC1) comprises at least 70 wt. %, based on the total weight of the 1.sup.st base polymer composition (BC1), of a 1.sup.st linear low density polyethylene (LLDPE1), said 1.sup.st linear low density polyethylene (LLDPE1) has a density in the range of 0.890 to 0.925 g/cm.sup.3 measured according to ISO 1183-187; (b) the core layer (CL) comprises at least 90 wt. %, based on the total weight of the core layer (CL), of a 2.sup.nd base polymer composition (BC2), said 2.sup.nd base polymer composition (BC2) comprises at least 75 wt. %, based on the total weight of the 2.sup.nd base polymer composition (BC2), of a propylene 1-hexene copolymer (PHC); and (c) the outer (OL) comprises at least 90 wt. %, based on the total weight of the outer (OL), of a 3.sup.rd base polymer composition (BC3), said 3.sup.rd base polymer composition (BC3) comprises at least 90 wt. %, based on the total weight of the 3.sup.rd base polymer composition (BC3), of a polyolefin; wherein said propylene 1-hexene copolymer (PHC) of the 2.sup.nd base polymer composition (BC2) has (i) an 1-hexene content in the range of 2.0 to 5.0 wt. % based on the total weight of the propylene 1-hexene copolymer (PHC); and (ii) a xylene soluble fraction (XCS) determined at 25° C. according to ISO 16152 in the range of 0.3 to 15.0 wt. % based on the total weight of the xylene soluble fraction (XCS) of the 1-hexene copolymer (PHC).

2. Multilayer film according to claim 1, wherein the propylene 1-hexene copolymer (PHC) comprises: (a) a 1.sup.st propylene 1-hexene copolymer (PHC-1) having an 1-hexene content in the range of 0.7 to 2.5 wt. % based on the total weight of the 1.sup.st propylene 1-hexene copolymer (PHC-1); and (b) a 2.sup.nd propylene 1-hexene copolymer (PHC-2) having an 1-hexene content in the range of 2.8 to 5.5 wt. %, based on the total weight of the 2.sup.nd propylene 1-hexene copolymer (PHC-2).

3. Multilayer film according to claim 2, wherein: (a) the total amount of the 1.sup.st propylene 1-hexene copolymer (PHC-1) and the 2.sup.nd propylene 1-hexene copolymer (PHC-2) together in the propylene 1-hexene copolymer (PHC) is at least 95 wt. % based on the total weight of the propylene 1-hexene copolymer (PHC); or (b) the propylene 1-hexene copolymer (PHC) consists of the propylene 1-hexene copolymers (PHC-1) and (PHC-2).

4. Multilayer film according to claim 2, wherein the weight ratio [(PHC-1)/(PHC-2)] between the 1.sup.st propylene 1-hexene copolymer (PHC-1) and the 2.sup.nd propylene 1-hexene copolymer (PHC-2) is in the range of 30/70 to 50/50.

5. Multilayer film according to claim 2, wherein the propylene 1-hexene copolymer (PHC) (a) fulfills the inequation (I): $5.00\le \frac{C6\left(\mathrm{PHC}\right)}{C6\left(\mathrm{PHC}-1\right)*\frac{\left[\mathrm{PHC}-1\right]}{\left\{\mathrm{PHC}\right]}}\le 7.50$ wherein C6 (PHC-1) is the 1-hexene content of the 1.sup.st propylene 1-hexene copolymer (PHC-1) based on the total weight of the 1.sup.st propylene 1-hexene copolymer (PHC-1) [in wt. %]; C6 (PHC) is the 1-hexene content of the propylene 1-hexene copolymer (PHC) based on the total weight of the propylene 1-hexene copolymer (PHC) [in wt. %]; [PHC-1]/[PHC] is the weight ratio between the 1.sup.st propylene 1-hexene copolymer (PHC-1) and the propylene 1-hexene copolymer (PHC) [in g/g].

6. Multilayer film according to claim 1, wherein the propylene 1-hexene copolymer (PHC) has: (a) a xylene soluble fraction (XCS) determined at 25° C. according to ISO 16152 in the range of 0.3 to 9.5 wt. % based on the total weight of the xylene soluble fraction (XCS) of the 1-hexene copolymer (PHC) or (b) an 1-hexene content in the range of 2.5 to 4.0 wt. %, based on the total weight of the propylene 1-hexene copolymer (PHC).

7. Multilayer film according to claim 1, wherein the propylene 1-hexene copolymer (PHC) has: (a) a molecular weight distribution (MWD) in the range of 3.0 to 4.3; and (b) 2,1 erythro regio defects in the range of 0.40 to 0.55 mol.-% determined by .sup.13C NMR spectroscopy.

8. Multilayer film according to claim 1, wherein the propylene 1-hexene copolymer (PHC) has: (a) a melting temperature in the range of 133 to 139° C. measured according to ISO 11357; and (b) a melt flow rate MFR.sub.2 (230° C./2.16 kg) measured according to ISO 1133 in the range of 0.5 to 8.0 g/10 min.

9. Multilayer film according to claim 1, wherein: (a) the core layer (CL) comprises at least 90 wt. %, based on the total weight of the core layer (CL), of the 2.sup.nd base polymer composition (BC2) and the remaining part up to 100 wt. %, based on the total weight of the core layer (CL), are additives (AD) selected from the group consisting of antioxidants, light stabilizers, acid scavengers, processing aids, anti-blocking aids, nucleating agents, slip agents and mixtures thereof; and (b) the 1.sup.st sealing layer (SL1) comprises at least 90 wt. %, based on the total weight of the 1.sup.st sealing layer (SL1), of the 1.sup.st base polymer composition (BC1) and the remaining part up to 100 wt. %, based on the total weight of the 1.sup.st sealing layer (SL1), are additives (AD) selected from the group consisting of antioxidants, light stabilizers, acid scavengers, processing aids, anti-blocking aids, nucleating agents, slip agents and mixtures thereof; and (c) the outer layer (OL) comprises at least 90 wt. %, based on the total weight of the outer layer (OL), of the 3.sup.rd base polymer composition (BC3) and the remaining part up to 100 wt. %, based on the total weight of the outer layer (OL), are additives (AD) selected from the group consisting of antioxidants, light stabilizers, acid scavengers, processing aids, anti-blocking aids, nucleating agents, slip agents and mixtures thereof.

10. Multilayer film according to claim 1, wherein the 2.sup.nd base polymer composition (BC2): (a) consists of the propylene 1-hexene copolymer (PHC), or (b) comprises (b1) 75 to 95 wt. %, based on the total weight of the 2.sup.nd base polymer composition (BC2), of the propylene 1-hexene copolymer (PHC), and (b2) 5 to 25 wt. %, based on the total weight of the 2.sup.nd base polymer composition (BC2), of a plastomer (PL), said plastomer being an elastomeric copolymer of ethylene and at least one C.sub.4 to C.sub.10 α-olefin.

11. Multilayer film according to claim 10, wherein the plastomer (PL) has glass transition temperature in the range of −60 to −35° C.

12. Multilayer film according to claim 10, wherein the plastomer (PL) has: (a) a density in the range of 0.860 to 0.930 g/cm.sup.3 measured according to ISO 1183-187; and (b) an ethylene content in the range of 65.0 to 95.0 wt. %.

13. Multilayer film according to claim 10, wherein the plastomer (PL) has a melting temperature below 100° C.

14. Multilayer film according to claim 1, wherein the outer (OL) is: (a) a heat shield layer (HSL) comprising at least 90 wt. %, based on the total weight of the heat shield layer (HSL), of a 3.sup.rd base polymer composition (BC3B) and the remaining part up to 100 wt. %, based on the total weight of the heat shield layer (HSL), are additives (AD) said 3.sup.rd base polymer composition (BC3B) comprises at least 90 wt. %, based on the total weight of the 3.sup.rd base polymer composition (BC3B), of a polypropylene having a melting temperature of at least 150° C. measured according to ISO 11357, or (b) a 2.sup.nd sealing layer (SL2), wherein said 2.sup.nd sealing layer (SL2) comprises at least 90 wt. %, based on the total weight of the 2.sup.nd sealing layer (SL2), of a 3.sup.rd base polymer composition (BC3A) and the remaining part up to 100 wt. %, based on the total weight of the 2.sup.nd sealing layer (SL2), are additives (AD); said 3.sup.rd base polymer composition (BC3A) comprises at least 70 wt. %, based on the total weight of the 3.sup.rd base polymer composition (BC3A), of a 2.sup.nd linear low density polyethylene (LLDPE2), said 2.sup.nd linear low density polyethylene (LLDPE2) has a density in the range of 0.890 to 0.925 g/cm.sup.3 measured according to ISO 1183-187.

15. Multilayer film according to claim 1, wherein the 1.sup.st linear low density polyethylene (LLDPE1) and the 2.sup.nd linear low density polyethylene (LLDPE2) have: (a) a melt flow rate MFR.sub.2 (190° C./2.16 kg) measured according to ISO 1133 in the range of 0.5 to 8.0 g/10 min; or (b) a comonomer content in the range of 1.5 to 5.0 mol.-% determined by quantitative NMR, the comonomers are selected from the group consisting of 1-butene, 1-hexene, 1-octene and mixtures thereof.

16. Multilayer film according to claim 1, wherein: (a) the 1.sup.st base polymer composition (BC1): (a1) consists of the 1.sup.st linear low density polyethylene (LLDPE1), or (a2) comprises 75 to 95 wt. %, based on the total weight of the 1.sup.st base polymer composition (BC1), of the 1.sup.st linear low density polyethylene (LLDPE1); and 5 to 25 wt. %, based on the total weight of the 1.sup.st base polymer composition (BC1), of a 1.sup.st low density polyethylene (LDPE1) having a density in the range of 0.915 to 0.935 g/cm.sup.3 measured according to ISO 1183-187; or (b) the outer layer (OL) is the 2.sup.nd sealing layer (SL2) as defined in claim 13, wherein further the 3.sup.rd base polymer composition (BC3A) (b1) consists of the 2.sup.nd linear low density polyethylene (LLDPE2), or (b2) comprises 75 to 95 wt. %, based on the total weight of the 3.sup.rd base polymer composition (BC3A), of the 2.sup.nd linear low density polyethylene (LLDPE2); and 5 to 25 wt. %, based on the total weight of the 3.sup.rd base polymer composition (BC3A), of a 1.sup.st low density polyethylene (LDPE2) having a density in the range of 0.915 to 0.935 g/cm.sup.3 measured according to ISO 1183-187.

17. Multilayer film according to claim 1, wherein: (a) the 1.sup.st linear low density polyethylene (LLDPE1) and the 2.sup.nd linear low density polyethylene (LLDPE2) are identical or (c) the 1.sup.st base polymer composition (BC1) and the 3.sup.rd base polymer composition (BC3A) are identical.

18. Multilayer film according to claim 1, wherein the film is a multilayer blown film, wherein said multilayer blown film consists of: (a) the 1.sup.st sealing layer (SL1), the core layer (CL) and the 2.sup.nd sealing layer (SL2), the stacking order of the three layers is (SL1)/(CL)/(SL2); or (b) the 1.sup.st sealing layer (SL1), the core layer (CL) and the heat shield layer (HSL), the stacking order of the three layers is (SL1)/(CL)/(HSL).

19. Base polymer composition (BPC) comprising: (a) 75 to 95 wt. %, based on the total weight of the base polymer composition (BPC), of a propylene 1-hexene copolymer (PHC) comprising a 1.sup.st propylene 1-hexene copolymer (PHC-1) and a 2.sup.nd propylene 1-hexene copolymer (PHC-2), and (b) 5 to 25 wt. %, based on the total weight of the 2.sup.nd base polymer composition (BC2), of a plastomer (PL) having a density in the range of 0.860 to 0.930 g/cm.sup.3 measured according to ISO 1183-187, said plastomer being an elastomeric copolymer of ethylene and at least one C.sub.4 to C.sub.10 α-olefin: wherein: (a1) said propylene 1-hexene copolymer (PHC) has an 1-hexene content in the range of 2.0 to 5.0 wt. %, based on the total weight of the propylene 1-hexene copolymer (PHC); (a2) the propylene 1-hexene copolymer (PHC) has a xylene soluble fraction (XCS) determined at 25° C. according to ISO 16152 in the range of 0.3 to 15.0 wt. %, based on the total weight of the xylene soluble fraction (XCS) of the propylene 1-hexene copolymer (PHC); (a3) said 1.sup.st propylene 1-hexene copolymer (PHC-1) has an 1-hexene content in the range of 0.7 to 2.5 wt. % based on the total weight of the 1.sup.st propylene 1-hexene copolymer (PHC-1); (a4) said 2.sup.nd propylene 1-hexene copolymer (PHC-2) has an 1-hexene content in the range of 2.8 to 5.5 wt. % based on the total weight of the 2.sup.nd propylene 1-hexene copolymer (PHC-2); (a5) the total amount of the 1.sup.st propylene 1-hexene copolymer (PHC-1) and the 2.sup.nd propylene 1-hexene copolymer (PHC-2) together based on the total weight of the propylene 1-hexene copolymer (PHC) is at least 95 wt. %; (a6) the weight ratio [(PHC-1)/(PHC-2)] between the 1.sup.st propylene 1-hexene copolymer (PHC-1) and the 2.sup.nd propylene 1-hexene copolymer (PHC-2) is in the range of 30/70 to 50/50.

20. Base polymer composition (BPC) according to claim 19, wherein propylene 1-hexene copolymer (PHC) is further defined according to claim 2 or the plastomer (PL) is further defined according to claim 11.

Description

EXAMPLES

1. Definitions/Measuring Methods

[0345] The following definitions of terms and determination methods apply for the above general description of the invention as well as to the below examples unless otherwise defined.

[0346] Melt Flow Rate

[0347] The melt flow rate (MFR) is determined according to ISO 1133 and is indicated in g/10 min. The MFR is an indication of the flowability, and hence the processability, of the polymer. The higher the melt flow rate, the lower the viscosity of the polymer. The MFR.sub.2 of polypropylene is determined at a temperature of 230° C. and a load of 2.16 kg. The MFR.sub.2 of polyethylene is determined at a temperature of 190° C. and a load of 2.16 kg.

[0348] Calculation of melt flow rate MFR.sub.2 (230° C.) of the propylene 1-hexene copolymer (PHC-2):

[00009]$MFR\left(B\right)={10}^{\left[\frac{\log \left(\mathrm{MF}R\left(P\right)\right)-w\left(A\right)x\log \left(\mathrm{MF}R\left(A\right)\right)}{w\left(B\right)}\right]}$

wherein [0349] w(A) is the weight fraction of the propylene 1-hexene copolymer (PHC-1); [0350] w(B) is the weight fraction of propylene 1-hexene copolymer (PHC-2); [0351] MFR(A) is the melt flow rate MFR.sub.2 (230° C.) [in g/10 min] measured according ISO 1133 of the propylene 1-hexene copolymer (PHC-1); [0352] MFR(P) is the melt flow rate MFR.sub.2 (230° C.) [in g/10 min] measured according ISO 1133 of the propylene 1-hexene copolymer (PHC); [0353] MFR(B) is the calculated melt flow rate MFR.sub.2 (230° C.) [in g/10 min] of the propylene 1-hexene copolymer (PHC-2).

[0354] Mw, Mn, MWD

[0355] Mw/Mn/MWD are measured by Gel Permeation Chromatography (GPC) according to the following method:

[0356] The weight average molecular weight (Mw), the number average molecular weight (Mn), and the molecular weight distribution (MWD=Mw/Mn) is measured by a method based on ISO 16014-1:2003 and ISO 16014-4:2003. A Waters Alliance GPCV 2000 instrument, equipped with refractive index detector and online viscosimeter is used with 3× TSK-gel columns (GMHXL-HT) from TosoHaas and 1,2,4-trichlorobenzene (TCB, stabilized with 200 mg/L 2,6-Di tert butyl-4-methyl-phenol) as solvent at 145° C. and at a constant flow rate of 1 mL/min. 216.5 μL of sample solution are injected per analysis. The column set is calibrated using relative calibration with 19 narrow MWD polystyrene (PS) standards in the range of 0.5 kg/mol to 11 500 kg/mol and a set of well characterized broad polypropylene standards. All samples are prepared by dissolving 5 to 10 mg of polymer in 10 mL (at 160° C.) of stabilized TCB (same as mobile phase) and keeping for 3 hours with continuous shaking prior sampling in into the GPC instrument.

[0357] Comonomer Content of 1-Hexene for a Propylene 1-Hexene Copolymer (PHC)

[0358] Quantitative .sup.13C {.sup.1H} NMR spectra recorded in the molten-state using a Bruker Avance III 500 NMR spectrometer operating at 500.13 and 125.76 MHz for .sup.1H and .sup.13C respectively. All spectra were recorded using a .sup.13C optimised 7 mm magic-angle spinning (MAS) probehead at 180° C. using nitrogen gas for all pneumatics. Approximately 200 mg of material was packed into a 7 mm outer diameter zirconia MAS rotor and spun at 4 kHz. This setup was chosen primarily for the high sensitivity needed for rapid identification and accurate quantification. (Klimke, K., Parkinson, M., Piel, C., Kaminsky, W., Spiess, H. W., Wilhelm, M., Macromol. Chem. Phys. 2006; 207:382., Parkinson, M., Klimke, K., Spiess, H. W., Wilhelm, M., Macromol. Chem. Phys. 2007; 208:2128., Castignolles, P., Graf, R., Parkinson, M., Wilhelm, M., Gaborieau, M., Polymer 50 (2009) 2373). Standard single-pulse excitation was employed utilising the NOE at short recycle delays of 3 s (Klimke, K., Parkinson, M., Piel, C., Kaminsky, W., Spiess, H. W., Wilhelm, M., Macromol. Chem. Phys. 2006; 207:382., Pollard, M., Klimke, K., Graf, R., Spiess, H. W., Wilhelm, M., Sperber, O., Piel, C., Kaminsky, W., Macromolecules 2004; 37:813.). and the RS-HEPT decoupling scheme (Filip, X., Tripon, C., Filip, C., J. Mag. Resn. 2005, 176, 239., Griffin, J. M., Tripon, C., Samoson, A., Filip, C., and Brown, S. P., Mag. Res. in Chem. 2007 45, S1, S198). A total of 16384 (16k) transients were acquired per spectra.

[0359] Quantitative .sup.13C {.sup.1H} NMR spectra were processed, integrated and relevant quantitative properties determined from the integrals. All chemical shifts are internally referenced to the methyl isotactic pentad (mmmm) at 21.85 ppm.

[0360] Characteristic signals corresponding to the incorporation of 1-hexene were observed and the comonomer content quantified in the following way.

[0361] The amount of 1-hexene incorporated in PHP isolated sequences was quantified using the integral of the αB4 sites at 44.2 ppm accounting for the number of reporting sites per comonomer:

H=IαB4/2

[0362] The amount of 1-hexene incorporated in PHHP double consecutive sequences was quantified using the integral of the ααB4 site at 41.7 ppm accounting for the number of reporting sites per comonomer:

HH=2*IααB4

[0363] When double consecutive incorporation was observed the amount of 1-hexene incorporated in PHP isolated sequences needed to be compensated due to the overlap of the signals αB4 and αB4B4 at 44.4 ppm:

H=(IαB4−2*IααB4)/2

[0364] The total 1-hexene content was calculated based on the sum of isolated and consecutively incorporated 1-hexene:

Htotal=H+HH

[0365] When no sites indicative of consecutive incorporation observed the total 1-hexeen comonomer content was calculated solely on this quantity:

Htotal=H

[0366] Characteristic signals indicative of regio 2,1-erythro defects were observed (Resconi, L., Cavallo, L., Fait, A., Piemontesi, F., Chem. Rev. 2000, 100, 1253).

[0367] The presence of 2,1-erythro regio defects was indicated by the presence of the Pαβ (21e8) and Pαγ (21e6) methyl sites at 17.7 and 17.2 ppm and confirmed by other characteristic signals.

[0368] The total amount of secondary (2,1-erythro) inserted propene was quantified based on the αα21e9 methylene site at 42.4 ppm:

P21=Iαα21e9

[0369] The total amount of primary (1,2) inserted propene was quantified based on the main Sαα methylene sites at 46.7 ppm and compensating for the relative amount of 2,1-erythro, αB4 and ααB4B4 methylene unit of propene not accounted for (note H and HH count number of hexene monomers per sequence not the number of sequences):

P12=I.sub.Sαα+2*P21+H+HH/2

[0370] The total amount of propene was quantified as the sum of primary (1,2) and secondary (2,1-erythro) inserted propene:

Ptotal=P12+P21=I.sub.Sαα+3*Iαα21e9+(IαB4−2*IααB4)/2+IααB4

[0371] This simplifies to:

Ptotal=I.sub.Sαα+3*Iαα21e9+0.5*IαB4

[0372] The total mole fraction of 1-hexene in the polymer was then calculated as:

fH=Htotal/(Htotal+Ptotal)

[0373] The full integral equation for the mole fraction of 1-hexene in the polymer was:

fH=(((IαB4−2*IααB4)/2)+(2*IααB4))/((I.sub.Sαα+3*Iαα21e9+0.5*IαB4)+((IαB4−2*IααB4)/2)+(2*IααB4))

[0374] This simplifies to:

fH=(IαB4/2+IααB4)/(I.sub.Sαα+3*Iαα21e9+IαB4+IααB4)

[0375] The total comonomer incorporation of 1-hexene in mole percent was calculated from the mole fraction in the usual manner:

H [mol %]=100*fH

[0376] The total comonomer incorporation of 1-hexene in weight percent was calculated from the mole fraction in the standard manner:

H [wt %]=100*(fH*84.16)/((fH*84.16)+((1−fH)*42.08))

[0377] Calculation of 1-hexene content of the propylene 1-hexene copolymer (PHC-2):

[00010]$\frac{C\left(PHC\right)-w\left(P\right)xC\left(A\right)}{w\left(B\right)}=C\left(B\right)$

wherein [0378] w(A) is the weight fraction of the propylene 1-hexene copolymer (PHC-1); [0379] w(B) is the weight fraction of the propylene 1-hexene copolymer (PHC-2); [0380] C(A) is the 1-hexene content [in wt.-%] measured by .sup.13C NMR spectroscopy of the propylene 1-hexene copolymer (PHC-1); [0381] C(PHC) is the 1-hexene content [in wt.-%] measured by .sup.13C NMR spectroscopy of the propylene 1-hexene copolymer (PHC); [0382] C(B) is the calculated 1-hexene content [in wt.-%] measured by .sup.13C NMR spectroscopy of the propylene 1-hexene copolymer (PHC-2);

[0383] Comonomer Content of 1-Octene of a Linear Low Density Polyethylene (LLDPE)

[0384] Quantitative nuclear-magnetic resonance (NMR) spectroscopy was used to quantify the comonomer content of the polymers.

[0385] Quantitative .sup.13C {.sup.1H} NMR spectra recorded in the molten-state using a Bruker Avance III 500 NMR spectrometer operating at 500.13 and 125.76 MHz for .sup.1H and .sup.13C respectively. All spectra were recorded using a .sup.13C optimised 7 mm magic-angle spinning (MAS) probehead at 150° C. using nitrogen gas for all pneumatics. Approximately 200 mg of material was packed into a 7 mm outer diameter zirconia MAS rotor and spun at 4 kHz. This setup was chosen primarily for the high sensitivity needed for rapid identification and accurate quantification (Klimke, K., Parkinson, M., Piel, C., Kaminsky, W., Spiess, H. W., Wilhelm, M., Macromol. Chem. Phys. 2006; 207:382.; Parkinson, M., Klimke, K., Spiess, H. W., Wilhelm, M., Macromol. Chem. Phys. 2007; 208:2128.; Castignolles, P., Graf, R., Parkinson, M., Wilhelm, M., Gaborieau, M., Polymer 50 (2009) 2373; NMR Spectroscopy of Polymers: Innovative Strategies for Complex Macromolecules, Chapter 24, 401 (2011)). Standard single-pulse excitation was employed utilising the transient NOE at short recycle delays of 3 s (Pollard, M., Klimke, K., Graf, R., Spiess, H. W., Wilhelm, M., Sperber, O., Piel, C., Kaminsky, W., Macromolecules 2004; 37:813.; Klimke, K., Parkinson, M., Piel, C., Kaminsky, W., Spiess, H. W., Wilhelm, M., Macromol. Chem. Phys. 2006; 207:382.) and the RS-HEPT decoupling scheme (Filip, X., Tripon, C., Filip, C., J. Mag. Resn. 2005, 176, 239.; Griffin, J. M., Tripon, C., Samoson, A., Filip, C., and Brown, S. P., Mag. Res. in Chem. 2007 45, S1, S198). A total of 1024 (1k) transients were acquired per spectrum. This setup was chosen due its high sensitivity towards low comonomer contents.

[0386] Quantitative .sup.13C {.sup.1H} NMR spectra were processed, integrated and quantitative properties determined using custom spectral analysis automation programs. All chemical shifts are internally referenced to the bulk methylene signal (δ+) at 30.00 ppm (J. Randall, Macromol. Sci., Rev. Macromol. Chem. Phys. 1989, C29, 201.).

[0387] Characteristic signals corresponding to the incorporation of 1-octene were observed (J. Randall, Macromol. Sci., Rev. Macromol. Chem. Phys. 1989, C29, 201.; Liu, W., Rinaldi, P., McIntosh, L., Quirk, P., Macromolecules 2001, 34, 4757; Qiu, X., Redwine, D., Gobbi, G., Nuamthanom, A., Rinaldi, P., Macromolecules 2007, 40, 6879) and all comonomer contents calculated with respect to all other monomers present in the polymer.

[0388] Characteristic signals resulting from isolated 1-octene incorporation i.e. EEOEE comonomer sequences, were observed. Isolated 1-octene incorporation was quantified using the integral of the signal at 38.37 ppm. This integral is assigned to the unresolved signals corresponding to both .sub.*B6 and .sub.*βB6B6 sites of isolated (EEOEE) and isolated double non-consecutive (EEOEOEE) 1-octene sequences respectively. To compensate for the influence of the two .sub.*βB6B6 sites the integral of the ββB6B6 site at 24.7 ppm is used:

O=I.sub.*B6+*βB6B6−2*I.sub.ββB6B6

[0389] Characteristic signals resulting from consecutive 1-octene incorporation, i.e. EEOOEE comonomer sequences, were also observed. Such consecutive 1-octene incorporation was quantified using the integral of the signal at 40.57 ppm assigned to the ααB6B6 sites accounting for the number of reporting sites per comonomer:

OO=2*I.sub.ααB6B6

[0390] Characteristic signals resulting from isolated non-consecutive 1-octene incorporation, i.e. EEOEOEE comonomer sequences, were also observed. Such isolated non-consecutive 1-octene incorporation was quantified using the integral of the signal at 24.7 ppm assigned to the ββB6B6 sites accounting for the number of reporting sites per comonomer:

OEO=2*I.sub.ββB6B6

[0391] Characteristic signals resulting from isolated triple-consecutive 1-octene incorporation, i.e. EEOEOEE comonomer sequences, were also observed. Such isolated triple-consecutive 1-octene incorporation was quantified using the integral of the signal at 41.2 ppm assigned to the ααγB6B6B6 sites accounting for the number of reporting sites per comonomer:

OOO=3/2*I.sub.ααγB6B6B6

[0392] With no other signals indicative of other comonomer sequences observed the total 1-octene comonomer content was calculated based solely on the amount of isolated (EEOEE), isolated double-consecutive (EEOOEE), isolated non-consecutive (EEOEOEE) and isolated triple-consecutive (EEOOOEE) 1-octene comonomer sequences:

O.sub.total=O+OO+OEO+OOO

[0393] Characteristic signals resulting from saturated end-groups were observed. Such saturated end-groups were quantified using the average integral of the two resolved signals at 22.84 and 32.23 ppm. The 22.84 ppm integral is assigned to the unresolved signals corresponding to both 2B6 and 2S sites of 1-octene and the saturated chain end respectively. The 32.23 ppm integral is assigned to the unresolved signals corresponding to both 3B6 and 3S sites of 1-octene and the saturated chain end respectively. To compensate for the influence of the 2B6 and 3B6 1-octene sites the total 1-octene content is used:

S=(½)*(I.sub.2S+2B6+I.sub.3S+3B6−2*O.sub.total)

[0394] The ethylene comonomer content was quantified using the integral of the bulk methylene (bulk) signals at 30.00 ppm. This integral included the γ and 4B6 sites from 1-octene as well as the δ.sup.+ sites. The total ethylene comonomer content was calculated based on the bulk integral and compensating for the observed 1-octene sequences and end-groups:

E.sub.total=(½)*[I.sub.bulk+2*O+1*OO+3*OEO+0*OOO+3*S]

[0395] It should be noted that compensation of the bulk integral for the presence of isolated triple-incorporation (EEOOOEE) 1-octene sequences is not required as the number of under and over accounted ethylene units is equal.

[0396] The total mole fraction of 1-octene in the polymer was then calculated as:

fO=(O.sub.total/(E.sub.total+O.sub.total)

[0397] The total comonomer incorporation of 1-octene in mol percent was calculated from the mole fraction in the standard manner:

O [mol %]=100*fO

[0398] The mole percent ethyelene incorporation was calculated from the formula:

E [mol %]=100−O [mol %].

[0399] Comonomer Content of 1-Butene and 1-Hexene of a Linear Low Density Polyethylene (LLDPE)

[0400] Quantitative .sup.13C {.sup.1H} NMR spectra recorded in the molten-state using a Bruker Avance III 500 NMR spectrometer operating at 500.13 and 125.76 MHz for .sup.1H and .sup.13C respectively. All spectra were recorded using a .sup.13C optimised 7 mm magic-angle spinning (MAS) probehead at 150° C. using nitrogen gas for all pneumatics. Approximately 200 mg of material was packed into a 7 mm outer diameter zirconia MAS rotor and spun at 4 kHz. This setup was chosen primarily for the high sensitivity needed for rapid identification and accurate quantification (Klimke, K., Parkinson, M., Piel, C., Kaminsky, W., Spiess, H. W., Wilhelm, M., Macromol. Chem. Phys. 2006; 207:382., Parkinson, M., Klimke, K., Spiess, H. W., Wilhelm, M., Macromol. Chem. Phys. 2007; 208:2128., Castignolles, P., Graf, R., Parkinson, M., Wilhelm, M., Gaborieau, M., Polymer 50 (2009) 2373). Standard single-pulse excitation was employed utilising the transient NOE at short recycle delays of 3 s (Pollard, M., Klimke, K., Graf, R., Spiess, H. W., Wilhelm, M., Sperber, O., Piel, C., Kaminsky, W., Macromolecules 2004; 37:813., Klimke, K., Parkinson, M., Piel, C., Kaminsky, W., Spiess, H. W., Wilhelm, M., Macromol. Chem. Phys. 2006; 207:382.) and the RS-HEPT decoupling scheme (Filip, X., Tripon, C., Filip, C., J. Mag. Resn. 2005, 176, 239, Griffin, J. M., Tripon, C., Samoson, A., Filip, C., and Brown, S. P., Mag. Res. in Chem. 2007 45, S1, S198). A total of 1024 (1k) transients were acquired per spectrum. This setup was chosen due its high sensitivity towards low comonomer contents.

[0401] Quantitative .sup.13C {.sup.1H} NMR spectra were processed, integrated and quantitative properties determined using custom spectral analysis automation programs. All chemical shifts are internally referenced to the bulk methylene signal (δ+) at 30.00 ppm (J. Randall, Macromol. Sci., Rev. Macromol. Chem. Phys. 1989, C29, 201).

[0402] The amount of ethylene was quantified using the integral of the methylene (δ+) sites at 30.00 ppm accounting for the number of reporting sites per monomer:

E=I.sub.δ+/2

the presence of isolated comonomer units is corrected for based on the number of isolated comonomer units present:

Etotal=E+(3*B+2*H)/2

where B and H are defined for their respective comonomers. Correction for consecutive and non-consecutive commoner incorporation, when present, is undertaken in a similar way. Characteristic signals corresponding to the incorporation of 1-butene were observed (J. Randall, Macromol. Sci., Rev. Macromol. Chem. Phys. 1989, C29, 201.) and all contents calculated with respect to all other monomers present in the polymer.

[0403] The amount isolated 1-butene incorporated in EEBEE sequences was quantified using the integral of the .sub.*B2 sites at 38.3 ppm accounting for the number of reporting sites per comonomer:

B=I.sub.*B2

[0404] The amount consecutively incorporated 1-butene in EEBBEE sequences was quantified using the integral of the ααB2B2 site at 39.4 ppm accounting for the number of reporting sites per comonomer:

BB=2*I.sub.ααB2B2

[0405] The amount non consecutively incorporated 1-butene in EEBEBEE sequences was quantified using the integral of the ββB2B2 site at 24.7 ppm accounting for the number of reporting sites per comonomer:

BEB=2*I.sub.ββB2B2

[0406] Due to the overlap of the *B2 and *βB2B2 sites of isolated (EEBEE) and non-consecutively incorporated (EEBEBEE) 1-butene respectively the total amount of isolated 1-butene incorporation is corrected based on the amount of non-consecutive 1-butene present:

B=I.sub.*B2−2*I.sub.ββB2B2

[0407] The total 1-butene content was calculated based on the sum of isolated, consecutive and non consecutively incorporated 1-butene:

Btotal=B+BB+BEB

[0408] The total mole fraction of 1-butene in the polymer was then calculated as:

fB=(Btotal)/(Etotal+Btotal+Htotal)

[0409] Characteristic signals corresponding to the incorporation of 1-hexene were observed (J. Randall, Macromol. Sci., Rev. Macromol. Chem. Phys. 1989, C29, 201.) and all contents calculated with respect to all other monomers present in the polymer.

[0410] The amount isolated 1-hexene incorporated in EEHEE sequences was quantified using the integral of the .sub.*B4 sites at 39.9 ppm accounting for the number of reporting sites per comonomer:

H=I.sub.*B4

[0411] The amount consecutively incorporated 1-hexene in EEHHEE sequences was quantified using the integral of the ααB4B4 site at 40.5 ppm accounting for the number of reporting sites per comonomer:

HH=2*I.sub.ααB4B4

[0412] The amount non consecutively incorporated 1-hexene in EEHEHEE sequences was quantified using the integral of the ββB4B4 site at 24.7 ppm accounting for the number of reporting sites per comonomer:

HEH=2*I.sub.ββB4B4

[0413] Due to overlap of the ββB2B2 sites of non-consecutively incorporated (EEBEBEE) 1-butene and ββB4B4 sites of non-consecutively incorporated (EEHEHEE) 1-hexene the total amount of non-consecutive incorporation (EEBEBEE) 1-butene was assumed to be proportional to the amount of isolated 1-butene (B) insertion and the total amount of non-consecutive incorporation (EEHEHEE) 1-hexene was assumed to be proportional to the amount of isolated 1-hexene (H).

[0414] The total mole fraction of 1-hexene in the polymer was then calculated as:

fH=(Htotal)/(Etotal+Btotal+Htotal)

[0415] The mole percent comonomer incorporation is calculated from the mole fraction:

B [mol %]=100*fB

H [mol %]=100*fH

[0416] The weight percent comonomer incorporation is calculated from the mole fraction:

B [wt %]=100*(fB*56.11)/((fB*56.11)+(fH*84.16)+((1−(fB+fH))*28.05))

H [wt %]=100*(fH*84.16)/((fB*56.11)+(fH*84.16)+((1−(fB+fH))*28.05))

[0417] Density is measured according to ISO 1183-187. Sample preparation is done by compression moulding in accordance with ISO 1872-2:2007.

[0418] Differential Scanning Calorimetry (DSC)

[0419] Differential scanning calorimetry (DSC) analysis, melting temperature (T.sub.m) and melt enthalpy (H.sub.m), crystallization temperature (T.sub.c), and heat of crystallization (H.sub.c) are measured with a TA Instrument Q200 differential scanning calorimetry (DSC) on 5 to 7 mg samples. DSC is run according to ISO 11357/part 3/method C2 in a heat/cool/heat cycle with a scan rate of 10° C./min in the temperature range of −30 to +225° C. Crystallization temperature (T.sub.c) and heat of crystallization (H.sub.c) are determined from the cooling step, while melting temperature (T.sub.m) and melt enthalpy (H.sub.m) are determined from the second heating step.

[0420] Dynamic Mechanical Thermal Analysis (DMTA)

[0421] The glass transition temperature T.sub.g is determined by dynamic mechanical thermal analysis (DMTA) according to ISO 6721-7. The measurements are done in torsion mode on compression moulded samples (40×10×1 mm.sup.3) between −100° C. and +150° C. with a heating rate of 2° C./min and a frequency of 1 Hz. Storage modulus G′ is determined at +23° C. according ISO 6721-7:1996. The measurements are done in torsion mode on compression moulded samples (40×10×1 mm.sup.3) between −150° C. and +150° C. with a heating rate of 2° C./min and a frequency of 1 Hz.

[0422] Xylene Cold Soluble (XCS) Content

[0423] Xylene Cold Soluble fraction at room temperature (XCS, wt %) is determined at 25° C. according to ISO 16152; 5th edition; Jul. 1, 2005.

[0424] Tensile Modulus

[0425] Tensile modulus in machine and transverse direction were determined according to ISO 527-3 at 23° C. on the multilayer films as produced indicated below. Testing was performed at a cross head speed of 1 mm/min.

[0426] Dart Drop Strength (DDI)

[0427] Dart-drop is measured using ASTM D1709, method A (Alternative Testing Technique) from the multilayer films as produced indicated below. A dart with a 38 mm diameter hemispherical head is dropped from a height of 0.66 m onto a multilayer film clamped over a hole. Successive sets of twenty specimens are tested. One weight is used for each set and the weight is increased (or decreased) from set to set by uniform increments. The weight resulting in failure of 50% of the specimens is calculated and reported.

[0428] Haze and clarity were determined according to ASTM D 1003-00 on multilayer films as produced indicated below.

[0429] Sealing Initiation Temperature (SIT)

[0430] The heat sealing initiation temperature (SIT) is the sealing temperature at which a sealing strength of >5 N is achieved.

[0431] The sealing range is determined on a J&B Universal Sealing Machine Type 3000 of the multilayer films as produced indicated below with the following parameters:

[0432] Specimen width: 25.4 mm

[0433] Seal Pressure: 0.1 N/mm.sup.2

[0434] Seal Time: 0.1 sec

[0435] Cool time: 99 sec

[0436] Peel Speed: 10 mm/sec

[0437] Start temperature 80° C.

[0438] End temperature: 150° C.

[0439] Increments: 10° C.

[0440] specimen is sealed A to A at each seal bar temperature and seal strength (force) is determined at each step.

[0441] The temperature is determined at which the seal strength reaches 5 N.

[0442] Hot Tack Force:

[0443] The hot tack force is determined on a DTC Hot tack tester Model 52-F/201 with the films as defined below with the following further parameters:

[0444] Specimen width: 25 mm

[0445] Seal Pressure: 1.2 N/mm.sup.2

[0446] Seal Time: 0.5 sec

[0447] Cool time: 0.2 sec

[0448] Peel Speed: 200 mm/sec

[0449] Start temperature: 90° C.

[0450] End temperature: 140° C.

[0451] The maximum hot tack force, i.e the maximum of a force/temperature diagram is determined and reported.

2. Examples

[0452] Preparation of the Catalyst System for the Inventive Examples

[0453] The catalyst used in the inventive example is prepared as described in detail in WO 2015/011135 A1 (metallocene complex MC1 with methylaluminoxane (MAO) and borate resulting in Catalyst 3 described in WO 2015/011135 A1) with the proviso that the surfactant is 2,3,3,3-tetrafluoro-2-(1,1,2,2,3,3,3-heptafluoropropoxy)-1-propanol. The metallocene complex (MC1 in WO 2015/011135 A1) is prepared as described in WO 2013/007650 A1 (metallocene E2 in WO 2013/007650 A1).

[0454] Polymerization and Pelletization

[0455] Polymer PH1 is produced in a Borstar pilot plant comprising a prepolymerisation reactor, a loop reactor and a gas phase reactor. The polymerisation conditions are indicated in Table 1. PH1 is the basis of the Inventive Examples.

[0456] Polymer PH1 was compounded in a co-rotating twin-screw extruder Coperion ZSK 57 at 220° C. with 0.2 wt % of Irganox B225 (1:1-blend of Irganox 1010 (Pentaerythrityl-5 tetrakis(3-(3′,5′-di-tert.butyl-4-hydroxytoluyl)-propionate and tris (2,4-di-t-butylphenyl) phosphate) phosphite) of BASF AG, Germany) and 0.1 wt % calcium stearate followed by solidification of the resulting melt strands in a water bath and pelletization.

[0457] Compounding of Material (M1) for the Sealing Layers (SL1) and (SL2)

[0458] Melt mixing was performed in a Thermo Fisher (PRISM) TSE 24 twin-screw extruder at 220° C. followed by solidification of the resulting melt strands in a water bath and pelletization. 90 wt.-% of the linear low density polyethylene “LLDPE” was mixed with 10 wt.-% of the low density polyethylene “FT5230” of Borealis AG.

[0459] The linear low density polyethylene “LLDPE” is example IE1 of EP 3 257 895 A1 having a 1-butene content of 0.3 mol.-%, a 1-hexene content of 2.6 mol.-%, density of 0.918 g/cm.sup.3 and a melt flow rate MFR.sub.2 (190° C., 2.16 kg) of 1.5 g/10 min;

[0460] The low density polyethylene “FT5230” of Borealis AG has a density of 923 g/cm.sup.3 and a melt flow rate MFR.sub.2 (190° C., 2.16 kg) of 0.75 g/10 min;

[0461] Compounding of Material (M2) for the Core Layer (CL)

[0462] Melt mixing was performed in a Thermo Fisher (PRISM) TSE 24 twin-screw extruder at 220° C. followed by solidification of the resulting melt strands in a water bath and pelletization. 90 wt.-% of the propylene 1-hexene copolymer PH1 (see comments above and table 1 below) was mixed with 10 wt.-% of the plastomer (PL) which is the commercial ethylene 1-octene plastomer “Queo 8201” of Borealis AG having a melt flow rate (190° C., 2.16 kg) of 1.1 g/10 min, a density of 0.882 g/cm.sup.3, an 1-octene content of 24.5 wt.-%, a melting temperature of 72° C. and a glass transition temperature of −52° C.

TABLE-US-00001 TABLE 1 Polymerization details of polymer PH1 PH1 Prepolymerization Temperature [° C.] 20 Pressure [kPa] 5247 Residence time [h] 0.4 Loop reactor Temperature [° C.] 70 Pressure [kPa] 5241 H2/C3 ratio [mol/kmol] 0.1 C6/C3 ratio [mol/kmol] 7.2 Residence time [h] 0.4 C6 [wt %] 1.3 MFR [g/10 min] 1.1 Split [wt %] 41 Gas phase reactor Temperature [° C.] 80 Pressure [kPa] 2500 H2/C3 ratio [mol/kmol] 1.7 C6/C3 ratio [mol/kmol] 7.0 C6(GPR) [wt %] 4.5 MFR(GPR) [g/10 min] 1.9 Residence time [h] 1.8 Split [wt %] 59 Product C6 total [wt %] 3.2 XCS [wt %] 0.7 C6 of XCS [wt %] 4.3 2,1e [mol.-%] 0.47 MWD [—] 3.7 MFR [g/10 min] 1.5 Tc [° C.] 94 Tm [° C.] 136

[0463] Three layer blown polymer films were produced on a three layer blown film line. The melt temperature of the sealing layers (SL1) and (SL2) was 185° C. to 195° C. The melt temperature of the core layer (CL) was in the range of 205° C. to 215° C. The throughput of the extruders was in sum 80 kg/h. The film structure was SL1-CL-SL2 with a core layer of 25 μm (CL) and two sealing layers (SL1) and (SL2) of 12.5 μm. Layer thickness has been determined by Scanning Electron Microscopy. The material used for the layers multilayer films is indicated in the table 2. The properties of the multilayer films are indicated in table 3.

TABLE-US-00002 TABLE 2 Layer structure of the multilayer films Thickness CE1 IE1 IE2 SL1 12.5 μm M1 M1 M1 CL   25 μm FX PH1 M2 SL2 12.5 μm M1 M1 M1 “FX” is the linear low density polyethylene “FX1001” of Borealis AG having a density of 0.933 g/cm.sup.3, a melting temperature of 127° C. and a melt flow rate MFR.sub.5 (190° C., 5 kg) of 0.85 g/10 min.

TABLE-US-00003 TABLE 3 Properties of the multilayer films CE1 IE1 IE2 Haze* [%] 6.93 4.11 4.06 Clarity* [%] 95.6 99.6 99.7 TM/MD [MPa] 324 566 500 TM/TD [MPa] 396 595 516 DDI [g] 608 430 674 SIT [° C.] 87 84 83 HTF [N] 5.7 7.4 4.8 *before sterilization