PLANT AND METHOD FOR THE PRODUCTION OF AN IN-LINE BLENDED POLYMER

Abstract

The present inventions concerns a plant producing an in-line blended polymer comprising a first polymerisation reactor and a second polymerisation reactor, the first and second polymerisation reactors having different internal volumes, and a method for producing an in-line blended polymer.

Claims

1. Plant for the production of an in-line blended polymer, the plant comprising a first reactor line for producing a first polymer, a second reactor line for producing a second polymer, and a blending unit for inline-blending the first polymer with the second polymer to obtain the inline-blended polymer, the first reactor line comprising a first polymerisation reactor for producing the first polymer and a first separator, the first separator being located downstream of the first polymerisation reactor, the second reactor line comprising a second polymerisation reactor for producing the second polymer and a second separator, the second separator being located downstream of the second polymerisation reactor, wherein both the first separator and the second separator are connected to the blending unit, the blending unit being located downstream of both the first separator and the second separator, wherein the first polymerisation reactor has a first internal volume and the second polymerisation reactor has a second internal volume, characterized in that the ratio of the first internal volume to the second internal volume is in the range from 95:5 to 55:45, and in that the blending unit comprises a flash separator.

2. The plant according to claim 1, wherein a first heater is located downstream of the first polymerisation reactor and upstream of the first separator, or wherein a second heater is located downstream of the second polymerization reactor and upstream of the second separator.

3. The plant according to claim 1, wherein the first separator comprises a top outlet and a bottom outlet, or wherein the second separator comprises a top outlet and a bottom outlet.

4. Plant for the production of an inline-blended polymer, the plant comprising a first polymerisation reactor for producing a first polymer, a second polymerisation reactor for producing a second polymer and a blending unit for inline-blending the first polymer with the second polymer to obtain to obtain the inline-blended copolymer, wherein both the first polymerisation reactor and the second polymerisation reactor are connected to the blending unit, the blending unit being located downstream of both the first polymerisation reactor and the second polymerisation reactor, wherein a first heater is located downstream of the first polymerisation reactor and upstream of the blending unit and/or wherein a second heater is located downstream of the second polymerisation reactor and upstream of the blending unit, wherein the first polymerisation reactor has a first internal volume and the second polymerisation reactor has a second internal volume, characterized in that the ratio of the first internal volume to the second internal volume is in the range from 95:5 to 55:45, and in that the blending unit comprises a flash separator.

5. The plant according to claim 1, wherein the first polymerisation reactor comprises a first reactor inlet for introducing a first feed stream into the first polymerisation reactor and a first reactor outlet for withdrawing a first reactor effluent stream comprising the first polymer or wherein the second polymerisation reactor comprises a second reactor inlet for introducing a second feed stream into the second polymerisation reactor and a second reactor outlet for withdrawing a second reactor effluent stream comprising the second polymer.

6. The plant according to claim 1, wherein the ratio of the first internal volume to the second internal volume is from 85:15 to 60:40.

7. The plant according to claim 1, wherein the blending unit has an outlet for withdrawing the inline-blended polymer.

8. Method for producing an in-line blended polymer, the method being performed in a plant according to claim 1, the method comprising the steps of a1) introducing a first feed stream comprising a first monomer into a first polymerisation reactor, a2) polymerising the first monomer in the presence of a first catalyst in the first polymerisation reactor to obtain a first polymer, a3) withdrawing a first reactor effluent stream comprising the first polymer from the first polymerisation reactor, b1) introducing a second feed stream comprising a second monomer into a second polymerisation reactor, b2) polymerising the second monomer in the presence of a second catalyst in the second polymerisation reactor to obtain a second polymer, b3) withdrawing a second reactor effluent stream comprising the second polymer from the second polymerisation reactor, c1) blending the first polymer and the second polymer in a blending unit to obtain the in-line blended polymer.

9. The method according to claim 8, wherein the first catalyst comprises a metallocene complex and/or the second catalyst comprises a metallocene complex.

10. The method according to claim 8, wherein polymerising step a2) is conducted at a first reaction temperature and polymerising step b2) is conducted at a second reaction temperature, wherein the first reaction temperature is the same as or different from the second reaction temperature.

11. The method according to claim 9, wherein polymerising step a2) is conducted at a first reactor pressure and polymerising step b2) is conducted at a second reactor pressure, wherein the first reactor pressure is the same as or different from the second reactor pressure.

12. The method according to claim 8, wherein the first monomer or the second monomer is ethylene.

13. The method according to claim 8, wherein the first feed stream further comprises a comonomer, or wherein the second feed stream further comprises a comonomer.

14. The method according to claim 8, wherein the first feed stream further comprises a solvent.

15. The method according to claim 13, wherein the comonomer is octene.

16. The method according to claim 8, wherein the first feed stream further comprises a chain transfer agent.

17. The method according to claim 8, wherein the second feed stream further comprises a solvent.

18. The method according to claim 8, wherein the second feed stream further comprises a chain transfer agent.

Description

[0211] To further illustrate the invention two exemplary embodiments of the invention are described using FIGS. 1 and 2.

[0212] FIG. 1 shows an exemplary embodiment the configuration of the plant according to the first aspect of the invention. The plant comprises a first reactor line and a second reactor line.

[0213] The first reactor line (1) for producing a first polymer includes a first polymerisation reactor (2) and a first separator (3). The first polymerisation reactor (2) comprises a first reactor inlet for introducing a first feed stream into the first reactor (2) and a first reactor outlet for withdrawing a first reactor effluent stream comprising the first polymer. The first reactor outlet is fluidly connected via a first connecting line (4) to an inlet of the first separator (3). The first separator (3) comprises a bottom outlet for withdrawing a first polymer-enriched liquid stream, the bottom outlet being connected via a second connecting line (14) to the blending unit (13). The first separator (3) further comprises a top outlet for withdrawing a first polymer-lean vapour stream. A first recycling line (5) connects the top outlet of the separator (3a) back to the first polymerisation reactor (2) to recycle the first polymer-lean vapour stream back into the first polymerisation reactor (2).

[0214] In analogy to the first reactor line (1), the second reactor line (7) according to the first aspect of the invention produces a second polymer and includes a second polymerisation reactor (8) and a second separator (9). The second polymerisation reactor (8) comprises a second reactor inlet for introducing a second feed stream into the reactor (8) and a second reactor outlet for withdrawing a second reactor effluent stream comprising the second polymer. The second reactor outlet is fluidly connected via a third connecting line (10) to an inlet of the second separator (9). The second separator (9) comprises a bottom outlet for withdrawing a second polymer-enriched liquid stream, the bottom outlet being connected via a fourth connecting line (15) to the blending unit (13). The second separator (9) further comprises a top outlet for withdrawing a second polymer-lean vapour stream. A recycling line (11) connects the top outlet of the separator (9) back to the second polymerisation reactor (8) to recycle the second polymer-lean vapour stream back into the second polymerisation reactor (8).

[0215] The internal volume of the first polymerisation reactor (2) is 1.5 times larger than the internal volume of the first polymerisation reactor (8).

[0216] A first heater (6) and a second heater (12) are located downstream of the first polymerisation reactor (2) and upstream of the blending unit (13) and downstream of second polymerisation reactor (9) and upstream of the blending unit (13), respectively, see FIG. 1.

[0217] The first heater (2a) heats the first reactor effluent stream to provide a heated first reactor effluent stream, the heated first reactor effluent stream being introduced into the first separator (3). The second heater (12) heats the second reactor effluent stream to provide a heated second reactor effluent stream, the heated second reactor effluent stream being introduced into the second separator (9).

[0218] The blending unit (13) is connected via the second connecting line (14) to the first separator (3) and via the fourth connecting line (15) to the second separator (9). Line (14) passes the first polymer-enriched liquid stream from the first separator (3) into the blending unit (13), whereas line (15) passes the second polymer-enriched liquid stream from the second separator (9) into the blending unit (13). In the blending unit (13), which is in this exemplary embodiment a static mixer, the first polymer from the first polymer-enriched liquid stream and the second polymer from the second polymer-enriched liquid stream are in-line blended so as to obtain an in-line blended polymer.

[0219] Blending unit (13) further comprises a bottom outlet connected to a withdrawing line (16) for withdrawing an in-line blended polymer stream comprising the in-line blended polymer.

[0220] FIG. 2 shows an exemplary embodiment of the configuration of the plant according to the second aspect of the invention.

[0221] The plant of the second aspect comprises a first polymerisation reactor (17a) and a second polymerisation reactor (17b). The first polymerisation reactor (17a) comprises a first reactor inlet (20a) for introducing a first feed stream into the reactor (17a) and a first reactor outlet for withdrawing a first reactor effluent stream comprising the first polymer. The first reactor outlet is fluidly connected via connecting line (21a) and line (22a) to an inlet of a blending unit (19). The blending unit (19) is in this exemplary embodiment a mixer.

[0222] The second polymerisation reactor (17b) comprises a second reactor inlet (20b) for introducing a second feed stream into the reactor (17b) and a second reactor outlet for withdrawing a second reactor effluent stream comprising the first polymer. The second reactor outlet is fluidly connected via connecting line (21b) and line (22b) to an inlet of the blending unit (19).

[0223] The internal volume of the first polymerisation reactor (17a) is 1.5 times larger than the internal volume of the second polymerisation reactor (17b) which is schematically seen in FIG. 2.

[0224] A first heater (18a) and a second heater (18b) are located downstream of the first polymerisation reactor (17a) and upstream of the blending unit (19) and downstream of second polymerisation reactor (17b) and upstream of the blending unit (19), respectively, see FIG. 2.

[0225] In the blending unit (19) the first polymer from the first reactor effluent stream and the second polymer from the second reactor effluent stream are in-line blended so as to obtain an in-line blended polymer.

[0226] Blending unit (19) further comprises a bottom outlet connected to a withdrawing line (23) for withdrawing an in-line blended polymer stream comprising the in-line blended polymer. A flash separator (24) is optionally located downstream of the blending unit (19).

EXAMPLE SECTION

1. Measurement Methods

[0227] a) Melt Flow Rate (MFR) and Flow Rate Ratio (FRR)

[0228] The melt flow rate (MFR) is determined according to IS01133—Determination of the melt mass-flow rate (MFR) and melt volume-flow rate (MVR) of thermoplastics—Part 1: Standard method, and is indicated in g/10 min. The MFR is an indication of flowability, and hence processability, of the polymer. The higher the melt flow rate, the lower the viscosity of the polymer.

[0229] The MFR.sub.2 of polypropylene is determined at a temperature of 230° C. and a load of 2.16 kg.

[0230] The MFR.sub.2 of polyethylene is determined at a temperature of 190° C. and a load of 2.16 kg.

[0231] The flow rate ratio (FRR) is the MFR.sub.21/MFR.sub.2.

[0232] b) Density

[0233] The density of the polymer was measured according to IS01183.

[0234] c) Comonomer Content

[0235] Quantitative nuclear-magnetic resonance (NMR) spectroscopy was used to quantify the comonomer content of the polymers.

[0236] 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. Standard single-pulse excitation was employed utilising the transient NOE at short recycle delays of 3 s and the RS-HEPT decoupling scheme. A total of 1024 (1 k) transients were acquired per spectrum.

[0237] 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 (d+) at 30.00 ppm.

[0238] Characteristic signals corresponding to the incorporation of 1-octene were observed and all comonomer contents calculated with respect to all other monomers present in the polymer.

[0239] 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 38.3 ppm. This integral is assigned to the unresolved signals corresponding to both *B6 and *bB6B6 sites of isolated (EEOEE) and isolated double non-consecutive (EEOEOEE) 1-octene sequences respectively. To compensate for the influence of the two *bB6B6 sites the integral of the bbB6B6 site at 24.6 ppm is used:

O=I.sub.*−B6+*bB6B6−2*I.sub.bbB6B6

[0240] 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 40.4 ppm assigned to the aaB6B6 sites accounting for the number of reporting sites per comonomer:

OO=2*I.sub.aaB6B6

[0241] 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 24.6 ppm assigned to the bbB6B6 sites accounting for the number of reporting sites per comonomer:

OEO=2*I.sub.bbB6B6

[0242] Characteristic signals resulting from isolated triple-consecutive 1-octene incorporation, i.e. EEOOOEE 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 aagB6B6B6 sites accounting for the number of reporting sites per comonomer:

OOO=3/2*I.sub.aagB6B6B6

[0243] 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

[0244] 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 22.9 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 32.2 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)

[0245] The ethylene comonomer content was quantified using the integral of the bulk methylene (bulk) signals at 30.00 ppm. This integral included the D and 4B6 sites from 1-octene as well as the D.sup.D 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+00*OOO+3*S]

[0246] 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.

[0247] The total mole fraction of 1-octene in the polymer was then calculated as:

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

[0248] The total comonomer incorporation of 1-octene in weight percent was calculated from the mole fraction in the standard manner:

O [wt %]=100*(fO*112.21)/((fO*112.21)+((1−fO)*28.05))

[0249] Further information can be found in the following references: [0250] Klimke, K., Parkinson, M., Piel, C., Kaminsky, W., Spiess, H. W., Wilhelm, M., Macromol. Chem. Phys. 2006; 207:382. [0251] Parkinson, M., Klimke, K., Spiess, H. W., Wilhelm, M., Macromol. Chem. Phys. 2007; 208:2128. [0252] NMR Spectroscopy of Polymers: Innovative Strategies for Complex Macromolecules, Chapter 24, 401 (2011) [0253] Pollard, M., Klimke, K., Graf, R., Spiess, H. W., Wilhelm, M., Sperber, O., Piel, C., Kaminsky, W., Macromolecules 2004; 37:813. [0254] Filip, X., Tripon, C., Filip, C., J. Mag. Resn. 2005, 176, 239 [0255] Griffin, J. M., Tripon, C., Samoson, A., Filip, C., and Brown, S. P., Mag. Res. in Chem. 2007 45, 51, S198 [0256] Castignolles, P., Graf, R., Parkinson, M., Wilhelm, M., Gaborieau, M., Polymer 50 (2009) 2373 [0257] Zhou, Z., Kuemmerle, R., Qiu, X., Redwine, D., Cong, R., Taha, A., Baugh, D. Winniford, B., J. Mag. Reson. 187 (2007) 225 [0258] Busico, V., Carbonniere, P., Cipullo, R., Pellecchia, R., Severn, J., Talarico, G., Macromol. Rapid Commun. 2007, 28, 1128 [0259] J. Randall, Macromol. Sci., Rev. Macromol. Chem. Phys. 1989, C29, 201. [0260] Qiu, X., Redwine, D., Gobbi, G., Nuamthanom, A., Rinaldi, P Macromolecules 2007, 40, 6879 [0261] Liu, W., Rinaldi, P., McIntosh, L., Quirk, P., Macromolecules 2001, 34, 4757

[0262] d) Unsaturation

[0263] Quantitative nuclear-magnetic resonance (NMR) spectroscopy was used to quantify the content of unsaturated groups present in the polymers.

[0264] Quantitative .sup.1H NMR spectra recorded in the solution-state using a Bruker Avance III 400 NMR spectrometer operating at 400.15 MHz. All spectra were recorded using a .sup.13C optimised 10 mm selective excitation probehead at 125° C. using nitrogen gas for all pneumatics. Approximately 200 mg of material was dissolved in 1,2-tetrachloroethane-d.sub.2 (TCE-d.sub.2) using approximately 3 mg of Hostanox 03 (CAS 32509-66-3) as stabiliser. Standard single-pulse excitation was employed utilising a 30 degree pulse, a relaxation delay of 10 s and 10 Hz sample rotation. A total of 128 transients were acquired per spectra using 4 dummy scans. This setup was chosen primarily for the high resolution needed for unsaturation quantification and stability of the vinylidene groups. All chemical shifts were indirectly referenced to TMS at 0.00 ppm using the signal resulting from the residual protonated solvent at 5.95 ppm.

[0265] Characteristic signals corresponding to the presence of terminal aliphatic vinyl groups (R—CH═CH.sub.2) were observed and the amount quantified using the integral of the two coupled inequivalent terminal CH.sub.2 protons (Va and Vb) at 4.95, 4.98 and 5.00 and 5.05 ppm accounting for the number of reporting sites per functional group:

Nvinyl=IVab/2

[0266] When characteristic signals corresponding to the presence of internal vinylidene groups (RR′C═CH.sub.2) were observed the amount is quantified using the integral of the two CH.sub.2 protons (D) at 4.74 ppm accounting for the number of reporting sites per functional group:

Nvinylidene=ID/2

[0267] When characteristic signals corresponding to the presence of internal cis-vinylene groups (E-RCH═CHR′), or related structure, were observed the amount is quantified using the integral of the two CH protons (C) at 5.39 ppm accounting for the number of reporting sites per functional group:

Ncis=IC/2

[0268] When characteristic signals corresponding to the presence of internal trans-vinylene groups (Z—RCH═CHR′) were observed the amount is quantified using the integral of the two CH protons (T) at 5.45 ppm accounting for the number of reporting sites per functional group:

Ntrans=IT/2

[0269] When characteristic signals corresponding to the presence of internal trisubstituted-vinylene groups (RCH═CHR′R″), or related structure, were observed the amount is quantified using the integral of the CH proton (Tris) at 5.14 ppm accounting for the number of reporting sites per functional group:

Ntris=ITris

[0270] The Hostanox 03 stabliser was quantified using the integral of multiplet from the aromatic protons (A) at 6.92, 6.91, 6.69 and at 6.89 ppm and accounting for the number of reporting sites per molecule:

H=IA/4

[0271] As is typical for unsaturation quantification in polyolefins the amount of unsaturation was determined with respect to total carbon atoms, even though quantified by .sup.1H NMR spectroscopy. This allows direct comparison to other microstructure quantities derived directly from .sup.13C NMR spectroscopy.

[0272] The total amount of carbon atoms was calculated from integral of the bulk aliphatic signal between 2.85 and −1.00 ppm with compensation for the methyl signals from the stabiliser and carbon atoms relating to unsaturated functionality not included by this region:

NCtotal=(Ibulk−42*H)/2+2*Nvinyl+2*Nvinylidene+2*Ncis+2*Ntrans+2*Ntris

[0273] The content of unsaturated groups (U) was calculated as the number of unsaturated groups in the polymer per thousand total carbons (kCHn):

U=1000*N/NCtotal

[0274] The total amount of unsaturated group was calculated as the sum of the individual observed unsaturated groups and thus also reported with respect per thousand total carbons:

Utotal=Uvinyl+Uvinylidene+Ucis+Utrans+Utris

[0275] The relative content of a specific unsaturated group (U) is reported as the fraction or percentage of a given unsaturated group with respect to the total amount of unsaturated groups:

[U]=Ux/Utotal

[0276] Further information can be found in the following references: [0277] He, Y., Qiu, X, and Zhou, Z., Mag. Res. Chem. 2010, 48, 537-542. [0278] Busico, V. et. al. Macromolecules, 2005, 38 (16), 6988-6996

[0279] e) Determination of the Molecular Weight Averages, Molecular Weight Distribution

[0280] Molecular weight averages (Mz, Mw and Mn), Molecular weight distribution (MWD) and its broadness, described by polydispersity index, PDI=Mw/Mn (wherein Mn is the number average molecular weight and Mw is the weight average molecular weight) were determined by Gel Permeation Chromatography (GPC) according to ISO 16014-1:2003, ISO 16014-2:2003, ISO 16014-4:2003 and ASTM D 6474-12 using the following formulas:

[00001]$\begin{array}{cc}{M}_n=\frac{{.Math.}_{i-1}^N{A}_i}{{.Math.}_{i=1}^N\left(A_i/M_i\right)}& \left(1\right)\end{array}$$\begin{array}{cc}{M}_w=\frac{{.Math.}_{i=1}^N\left(A_i\times M_i\right)}{{.Math.}_{i=1}^N{A}_i}& \left(2\right)\end{array}$$\begin{array}{cc}{M}_z=\frac{{.Math.}_{i=1}^N\left(A_i\times M_i^2\right)}{{.Math.}_{i=1}^N\left(A_i/M_i\right)}& \left(3\right)\end{array}$

[0281] For a constant elution volume interval ΔV.sub.i, where A.sub.i, and M.sub.i are the chromatographic peak slice area and polyolefin molecular weight (MW), respectively associated with the elution volume, V.sub.i, where N is equal to the number of data points obtained from the chromatogram between the integration limits.

[0282] A high temperature GPC instrument, equipped with a multiple band infrared detector model IR5 (PolymerChar, Valencia, Spain), equipped with 3× Agilent-PLgel Olexis and 1× Agilent-PLgel Olexis Guard columns was used. As the solvent and mobile phase 1,2,4-trichlorobenzene (TCB) stabilized with 250 mg/L 2,6-Di tert butyl-4-methyl-phenol) was used. The chromatographic system was operated at 160° C. at a constant flow rate of 1 mL/min. 200 μL of sample solution was injected per analysis. Data collection was performed by using PolymerChar GPC-one software.

[0283] The column set was calibrated using universal calibration (according to ISO 16014-2:2003) with 19 narrow MWD polystyrene (PS) standards in the range of 0.5 kg/mol to 11 500 kg/mol. The PS standards were dissolved at room temperature over several hours. The conversion of the polystyrene peak molecular weight to polyolefin molecular weights is accomplished by using the Mark Houwink equation and the following Mark Houwink constants:

K.sub.PS=19×10.sup.−3 mL/g, α.sub.PS=0.655

K.sub.PE=39×10.sup.−3 mL/g, α.sub.PE=0.725

[0284] A third order polynomial fit was used to fit the calibration data.

[0285] All samples were prepared in the concentration range of 0.5 to 1 mg/ml and dissolved at 160° C. for 3 hours under continuous gentle shaking.

[0286] f) Melting Temperature (T.sub.m) and Crystallization Temperature (T.sub.c)

[0287] Experiments were performed with a TA Instruments Q200, calibrated with Indium, Zinc, Tin and according to ISO 11357-3. Roughly 5 mg of material were placed in a pan and tested at 10° C./min throughout the experiments, under 50 mL/min nitrogen flow, with lower and higher temperatures of −30° C. and 180° C. respectively. Only the second heating run was considered for the analysis. The melting temperature T.sub.m is defined as the temperature of the main peak of the thermogram, while the melting enthalpy (ΔHm) is calculated by integrating between 10° C. and the end of the thermogram, typically T.sub.m+15° C. The running integral in this range is also calculated.

[0288] g) Glass Transition Temperature (T.sub.g)

[0289] The glass transition temperature Tg is determined by dynamic mechanical analysis according to ISO 6721-7. The measurements are done in torsion mode on compression moulded samples (40×10×1 mm3) between −100° C. and +150° C. with a heating rate of 2° C./min and a frequency of 1 Hz.

[0290] h) Vicat Softening Temperature (T.sub.vicat)

[0291] The Vicat temperature is measured according to ISO 306, method A50. A flat-ended needle loaded with a mass of 10 N is placed in direct contact with an injection moulded test specimen with the dimensions of 80×10×4 mm3 as described in EN ISO 1873-2. The specimen and the needle are heated at 50° C./h. The temperature at which the needle has penetrated to a depth of 1 mm is recorded as the Vicat softening temperature.

[0292] 2. Materials [0293] a) Comparative Example 1 (CE1) [0294] CE1 is an ethylene based octene-1 plastomer (octene content 15.7 wt. %) having an MFR2 of 1.1 g/10 min, a density of 902 kg/m.sup.3 and a melting temperature T.sub.m of 97° C., commercially available from Borealis. CE1 was produced in a solution polymerisation process using a metallocene catalyst. [0295] b) Copolymer A is an ethylene based octene-1 plastomer (amount octene 11.9 wt. %), produced in a solution polymerisation process using a metallocene catalyst, having an MFR2 of 1.1 g/10 min, a density of 910 kg/m.sup.3 and a melting temperature T.sub.m of 106° C. [0296] Copolymer B is an ethylene based octene-1 plastomer (amount octene 25.8 wt. %), produced in a solution polymerisation process using a metallocene catalyst, having an MFR2 of 1.1 g/10 min, a density of 883 kg/m.sup.3 and a melting temperature T.sub.m of 73° C. [0297] d) Copolymer C is an ethylene based octene-1 elastomer (amount octene 37.1 wt. %), produced in a solution polymerisation process using a metallocene catalyst, having an MFR2 of 1.0 g/10 min, a density of 862 kg/m.sup.3 and a melting temperature T.sub.m of 35 ° C. [0298] e) Copolymer D is an ethylene based octene-1 elastomer (amount octene 31.5 wt %), produced in a solution polymerisation process using a metallocene catalyst, having an MFR2 of 1.0 g/10 min, a density of 870 kg/m.sup.3 and a melting temperature T.sub.m of 56° C.

[0299] Copolymers A to D were produced with Borealis proprietor Borceed™ solution polymerization technology, in the present of metallocene catalyst (phenyl)(cyclohexyl) methylene (cyclopentadienyl) (2,7-di-tert-butylfluorenyl) hafnium dimethyl and N,N-Dimethylanilinium Tetrakis(pentafluorophenyl)borate (AB) (CAS 118612-00-3) was used, commercially available from Boulder, as cocatalyst.

[0300] The polymerization conditions, were selected in such a way that the reacting system is one liquid phase. (T between 130 and 230° C.; 60 to 150 bar)

[0301] 3. Results

[0302] Blending of the respective material was done using Prism TSE-16, a 16 mm co-rotating twin screw extruder with L/D 25, with throughput of approximately 1.4 kg/h. Temperature profile was set to 180-200° C. and the machine was operated at 250 rpm. Samples were produced by mixing a dry blend of base resin pellets and extruding said mixture. Around 2.5 kg of dry blend was fed to hopper for the batch and after stabilisation around 2.0 kg of the final extruded blend was collected.

[0303] The inventive examples 1E1-1 to 1E1-3 are blends of two copolymers in specific blend ratios. Results are provided in Table 1 below.

TABLE-US-00001 TABLE 1 Results CE1 IE1-1 IE1-2 IE1-3 Blend ratio — 83 wt. % 80 wt. % 71 wt. % Copo. A Copo. A Copo. A 17 wt. % 20 wt. % 29 wt. % Copo. C Copo. D Copo. B C8 content, 15.7 14.9 15.2 15.3 wt. % Density, 902 902 903.1 902.1 kg/m.sup.3 M.sub.w, g/mol 81650 81350 82800 82250 M.sub.w/M.sub.n 2.6 2.72 2.64 2.72 MFR.sub.2, g/10 min 1.1 1.02 0.99 1.03 MFR.sub.21, g/10 min 31.54 37.05 37.53 36.3 MFR.sub.21/MFR.sub.2 30.62 36.32 37.91 35.24 T.sub.m, ° C. 97 102.63 103.7 102.01 T.sub.c, ° C. 78.42 89.9 T.sub.g, ° C. −35.48 −41.55 −41.55 T.sub.Vicat, ° C. 82 87.2 Vinylidene, 12.3 11.5 12.1 12.1 100kCHn Vinyl, 5.6 5.0 6.9 5.8 100kCHn Trisubst, 19.2 17.7 17.40 21.2 100kCHn Vinylene, 8.8 12.7 14.40 14.0 100kCHn

[0304] The above results show that blending two different copolymers targeting an existing product (CE1) leads to copolymers (1E1-1 to 1E1-3) with significantly better melting temperature T.sub.m as well as improved T.sub.g, improved T.sub.c and improved T.sub.Vicat at comparable density, melt flow rate, M.sub.w and 1-octene comonomer content.