Soft bottles

Abstract

Molded article comprising a propylene copolymer having a xylene cold soluble content (XCS) in the range of 35 to 60 wt.-% and a comonomer content in the range of 7.0 to 17.0 wt-%, wherein further the propylene copolymer fulfills inequation (I), wherein Co (total) is the comonomer content [wt.-%] of the propylene copolymer Co (XCS) is the comonomer content [wt.-%] of the xylene cold soluble fraction (XCS) of the propylene copolymer. $\begin{array}{cc}\frac{\mathrm{Co}\left(\mathrm{total}\right)}{\mathrm{Co}\left(\mathrm{XCS}\right)}0.50& \left(I\right)\end{array}$

Claims

1. Molded article comprising a propylene copolymer having: (a) a xylene cold soluble content (XCS) determined according ISO 16152 (25 C.) in the range of 35 to 60 wt. %, (b) a comonomer content in the range of 7.0 to 17.0 wt. %, wherein further the propylene copolymer fulfills inequation (I): $\frac{\mathrm{Co}\left(\mathrm{total}\right)}{\mathrm{Co}\left(\mathrm{XCS}\right)}0.50$ wherein Co (total) is the comonomer content [wt. %] of the propylene copolymer, Co (XCS) is the comonomer content [wt. %] of the xylene cold soluble fraction (XCS) of the propylene copolymer, and wherein the propylene copolymer is a heterophasic propylene copolymer (RAHECO) comprising a matrix (M) and an elastomeric propylene copolymer (E) dispersed in said matrix (M), wherein said matrix (M) is a random propylene copolymer (R-PP) having a comonomer content of at least 4.0 wt. %.

2. Molded article according to claim 1, wherein the comonomer content of xylene cold soluble (XCS) fraction of the propylene copolymer is in the range of 8.0 to 20.0 wt. %.

3. Molded article according to claim 1, wherein the amount of the propylene copolymer in the molded article is at least 50 wt. % based on the total weight of the molded article.

4. Molded article according to claim 1, wherein the propylene copolymer comprises: (a) a melting temperature Tm determined by differential scanning calorimetry (DSC) in the range of 145 to 160 C., and/or (b) an intrinsic viscosity (IV) of the xylene cold soluble (XCS) fraction determined according to DIN ISO 1628/1 (in Decalin at 135 C.) in the range of 1.5 to below 2.8 dl/g.

5. Molded article according to claim 1, wherein the propylene copolymer has a melt flow rate MFR.sub.2 (230 C.) measured according to ISO 1133 in the range of 0.5 to 2.5 g/10 min.

6. Molded article according to claim 1, wherein the propylene copolymer comprises: (a) a flexural modulus measured according to ISO 178 of not more than 350 MPa, and/or (b) a haze before sterilization determined according to ASTM D 1003-07 of below 30%, and/or (c) a haze after sterilization determined according to ASTM D 1003-07 of below 50%.

7. Molded article according to claim 1, wherein the weight ratio between the matrix (M) and the elastomeric propylene copolymer (E) is 50/50 to 80/20.

8. Molded article according to claim 1, wherein, (a) the comonomer content of the random propylene copolymer (R-PP) is in the range of 4.0 to 15.0 wt.-%, and/or (b) the propylene copolymer fulfills inequation (II): $\frac{\mathrm{Co}\left(\mathrm{total}\right)}{\mathrm{Co}\left(\mathrm{RPP}\right)}0.9$ wherein Co (total) is the comonomer content [wt. %] of the propylene copolymer, and Co (RPP) is the comonomer content [wt. %] of the random propylene copolymer (R-PP), and/or (c) the random propylene copolymer (R-PP) has a xylene cold soluble (XCS) fraction in the range of 20 to 45 wt. %.

9. Molded article according to claim 1, wherein the random propylene copolymer (R-PP) of the heterophasic propylene copolymer (RAHECO) comprises at least two different fractions, a first random propylene copolymer fraction (R-PP1) and a second random propylene copolymer fraction (R-PP2), wherein further: (a) the weight ratio between the first random propylene copolymer fraction (R-PP1) and the second random propylene copolymer fraction (R-PP2) 20/80 to 80/20, and/or (b) the first random propylene copolymer fraction (R-PP1) has a comonomer content in the range 0.5 to 5.0 wt. %, and/or (c) the second random propylene copolymer fraction (R-PP2) has a comonomer content in the range 7.0 to 20.0 wt. %.

10. Molded article according to claim 1, wherein the elastomeric propylene copolymer (E) of the heterophasic propylene copolymer (RAHECO) has a comonomer content in the range of 10.0 to 22.0 wt. %.

11. Molded article according to claim 1, wherein the article is a blow molded article.

12. Molded article according to claim 1, wherein the article is a bottle.

13. Molded article comprising a propylene copolymer having: (a) a xylene cold soluble content (XCS) determined according ISO 16152 (25 C.) in the range of 35 to 60 wt. %, and (b) a comonomer content in the range of 7.0 to 17.0 wt. %, wherein further the comonomer content of xylene cold soluble (XCS) fraction of the propylene copolymer is in the range of 8.0 to 20.0 wt. %, and wherein the propylene copolymer is a heterophasic propylene copolymer (RAHECO) comprising a matrix (M) and an elastomeric propylene copolymer (E) dispersed in said matrix (M), wherein said matrix (M) is a random propylene copolymer (R-PP) having a comonomer content of at least 4.0 wt. %.

14. Molded article according to claim 13, wherein the propylene copolymer fulfills inequation (I): $\frac{\mathrm{Co}\left(\mathrm{total}\right)}{\mathrm{Co}\left(\mathrm{XCS}\right)}0.50$ wherein Co (total) is the comonomer content [wt. %] of the propylene copolymer, and Co (XCS) is the comonomer content [wt. %] of the xylene cold soluble fraction (XCS) of the propylene copolymer.

Description

EXAMPLES

(1) 1. Measuring Methods

(2) 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. Calculation of comonomer content of the second propylene copolymer fraction (R-PP2):

(3) $\begin{array}{cc}\frac{C\left(\mathrm{PP}\right)-w\left(\mathrm{PP}1\right)C\left(\mathrm{PP}1\right)}{w\left(\mathrm{PP}2\right)}=C\left(\mathrm{PP}2\right)& \left(I\right)\end{array}$ wherein w(PP1) is the weight fraction [in wt.-%] of the first propylene copolymer fraction (R-PP1), w(PP2) is the weight fraction [in wt.-%] of second propylene copolymer fraction (R-PP2), C(PP1) is the comonomer content [in wt.-%] of the first propylene copolymer fraction (R-PP1), C(PP) is the comonomer content [in wt.-%] of the random propylene copolymer (R-PP), C(PP2) is the calculated comonomer content [in wt.-%] of the second propylene copolymer fraction (R-PP2).

(4) Calculation of the xylene cold soluble (XCS) content of the second propylene copolymer fraction (R-PP2):

(5) $\begin{array}{cc}\frac{\mathrm{XS}\left(\mathrm{PP}\right)-w\left(\mathrm{PP}1\right)\mathrm{XS}\left(\mathrm{PP}1\right)}{w\left(\mathrm{PP}2\right)}=\mathrm{XS}\left(\mathrm{PP}2\right)& \left(\mathrm{II}\right)\end{array}$ wherein w(PP1) is the weight fraction [in wt.-%] of the first propylene copolymer fraction (R-PP1), w(PP2) is the weight fraction [in wt.-%] of second propylene copolymer fraction (R-PP2), XS(PP1) is the xylene cold soluble (XCS) content [in wt.-%] of the first propylene copolymer fraction (R-PP1), XS(PP) is the xylene cold soluble (XCS) content [in wt.-%] of the random propylene copolymer (R-PP), XS(PP2) is the calculated xylene cold soluble (XCS) content [in wt.-%] of the second propylene copolymer fraction (R-PP2), respectively.

(6) Calculation of melt flow rate MFR.sub.2 (230 C.) of the second propylene copolymer fraction (R-PP2):

(7) $\begin{array}{cc}\mathrm{MFR}\left(\mathrm{PP}2\right)=10\left[\frac{\log \left(\mathrm{MFR}\left(\mathrm{PP}\right)\right)-w\left(\mathrm{PP}1\right)\log \left(\mathrm{MFR}\left(\mathrm{PP}1\right)\right)}{w\left(\mathrm{PP}2\right)}\right]& \left(\mathrm{III}\right)\end{array}$ wherein w(PP1) is the weight fraction [in wt.-%] of the first propylene copolymer fraction (R-PP1), w(PP2) is the weight fraction [in wt.-%] of second propylene copolymer fraction (R-PP2), MFR(PP1) is the melt flow rate MFR.sub.2 (230 C.) [in g/10 min] of the first propylene copolymer fraction (R-PP1), MFR(PP) is the melt flow rate MFR.sub.2 (230 C.) [in g/10 min] of the random propylene copolymer (R-PP), MFR(PP2) is the calculated melt flow rate MFR.sub.2 (230 C.) [in g/10 min] of the second propylene copolymer fraction (R-PP2).

(8) Calculation of comonomer content of the elastomeric propylene copolymer (E), respectively:

(9) $\begin{array}{cc}\frac{C\left(\mathrm{RAHECO}\right)-w\left(\mathrm{PP}\right)C\left(\mathrm{PP}\right)}{w\left(E\right)}=C\left(E\right)& \left(\mathrm{IV}\right)\end{array}$ wherein w(PP) is the weight fraction [in wt.-%] of the random propylene copolymer (R-PP), i.e. polymer produced in the first and second reactor (R1+R2), w(E) is the weight fraction [in wt.-%] of the elastomeric propylene copolymer (E), i.e. polymer produced in the third and fourth reactor (R3+R4) C(PP) is the comonomer content [in wt.-%] of the random propylene copolymer

(10) (R-PP), i.e. comonomer content [in wt.-%] of the polymer produced in the first and second reactor (R1+R2), C(RAHECO) is the comonomer content [in wt.-%] of the propylene copolymer, i.e. is the comonomer content [in wt.-%] of the polymer obtained after polymerization in the fourth reactor (R4), C(E) is the calculated comonomer content [in wt.-%] of elastomeric propylene copolymer (E), i.e. of the polymer produced in the third and fourth reactor (R3+R4). MFR.sub.2 (230 C.) is measured according to ISO 1133 (230 C., 2.16 kg load).

(11) Comonomer content, especially ethylene content is measured with Fourier transform infrared spectroscopy (FTIR) calibrated with .sup.13C-NMR. When measuring the ethylene content in polypropylene, a thin film of the sample (thickness about 250 m) was prepared by hot-pressing. The area of absorption peaks 720 and 733 cm.sup.1 for propylene-ethylene-copolymers was measured with Perkin Elmer FTIR 1600 spectrometer. Propylene-1-butene-copolymers were evaluated at 767 cm.sup.1. The method was calibrated by ethylene content data measured by .sup.13C-NMR. See also IR-Spektroskopie fr Anwender; WILEY-VCH, 1997 and Validierung in der Analytik, WILEY-VCH, 1997.

(12) Intrinsic viscosity is measured according to DIN ISO 1628/1, October 1999 (in Decalin at 135 C.).

(13) The xylene solubles (XCS, wt.-%): Content of xylene cold solubles (XCS) is determined at 25 C. according ISO 16152; first edition; 2005-07-01.

(14) Hexane Solubles

(15) 1 g of the sample was put into a 300 ml Erlenmeyer flask and 100 ml of hexane was added. The mixture was boiled under stirring in a reflux condenser for 4 h. The hot solution was immediately filtered through a folded filter paper N.sup.o 41 and dried (in a vacuum oven at 90 C.) and weighted (0.0001 g exactly) in a round shenk. The Erlenmeyer flask and the filter were washed with n-hexane. Then the hexane was evaporated under a nitrogen stream on a rotary evaporator. The round shenk was dried in a vacuum oven at 90 C. over night and was put into a desiccator for at least 2 hours to cool down. The shenk was weighted again and the hexane soluble was calculated therefrom.

(16) Melting temperature (T.sub.m) is measured with Mettler TA820 differential scanning calorimetry (DSC) on 5 to 10 mg samples. DSC is run according to ISO 11357-3:1999 in a heat/cool/heat cycle with a scan rate of 10 C./min in the temperature range of +23 to +210 C.

(17) Haze was determined according to ASTM D1003-07 on 60601 mm.sup.3 plaques injection molded in line with EN ISO 1873-2 using a melt temperature of 200 C.

(18) Flexural Modulus: The flexural modulus was determined in 3-point-bending at 23 C. according to ISO 178 on 80104 mm.sup.3 test bars injection moulded in line with EN ISO 1873-2.

(19) Steam sterilization was performed in a Systec D series machine (Systec Inc., USA). The samples were heated up at a heating rate of 5 C./min starting from 23 C. After having been kept for 30 min at 121 C., they were removed immediately from the steam sterilizer and stored at room temperature till processed further.

(20) Description/Dimension of the Bottles

(21) 1 l bottles, having an outer diameter of 90 mm, wall thickness: 0.6 mm; overall-height of 204 mm, height of the cylindrical mantle of 185 mm

(22) Drop Test on Bottles (Bracketing)

(23) The drop test is performed on extrusion blow moulded 1 l bottles, having an outer diameter of 90 mm, a wall thickness of 0.6 mm, an overall-height of 204 mm and a height of the cylindrical mantle of 185 mm. The bottles are filled up to their shoulder with water.

(24) During a pre-test the estimated falling height is determined on 10 bottles.

(25) The final test is to be performed on 20 bottles, starting at the pre-determined falling height. For each run 2 bottles are dropped.

(26) Depending on 2 breaks or 1 break/1 no-break (=neutral) or 2 no-breaks, the next dropping height is chosen to be lower/same/higher for the next round.

(27) The increase or decrease in height is 0.25 m, only at dropping heights <1.5 m the increase or decrease is 0.1 m.

(28) The final drop height is determined depending on the falling heights of the containers after the first change in trend or after the first neutral result according following formula:
he=(ni.Math.hi)/ng wherein he=50% drop height hi=drop height ni=number of containers dropped at the respective height ng=total number of dropped containers
Transparency, Clarity and Haze Measurement on Bottles

(29) Instrument: Haze-gard plus from BYK-Gardner

(30) Testing: according to ASTM D1003 (as for injection molded plates)

(31) Method: The measurement is done on the outer wall of the bottles. The top and bottom of the bottles are cut off. The resulting round wall is then split in two, horizontally. Then from this wall six equal samples of app. 6060 mm are cut from close to the middle. The specimens are placed into the instrument with their convex side facing the haze port. Then the transparency, haze and clarity are measured for each of the six samples and the haze value is reported as the average of these six parallels.

(32) Tensile Test on Bottles

(33) The top and bottom of the bottles is cut off 12 specimen according to ISO527/1B are punched along the remaining cylinder. Tensile modulus and tensile stress are then determined according to ISO 527-2, applying a traction speed of 1 mm/min for the modulus and 100 mm/min for yield strength.

(34) 2. Examples

(35) The catalyst used in the polymerization process for the comparative and inventive examples has been produced as follows: First, 0.1 mol of MgCl.sub.23 EtOH was suspended under inert conditions in 250 ml of decane in a reactor at atmospheric pressure. The solution was cooled to the temperature of 15 C. and 300 ml of cold TiCl.sub.4 was added while maintaining the temperature at said level. Then, the temperature of the slurry was increased slowly to 20 C. At this temperature, 0.02 mol of dioctylphthalate (DOP) was added to the slurry. After the addition of the phthalate, the temperature was raised to 135 C. during 90 minutes and the slurry was allowed to stand for 60 minutes. Then, another 300 ml of TiCl.sub.4 was added and the temperature was kept at 135 C. for 120 minutes. After this, the catalyst was filtered from the liquid and washed six times with 300 ml heptane at 80 C. Then, the solid catalyst component was filtered and dried. Catalyst and its preparation concept is described in general e.g. in patent publications EP491566, EP591224 and EP586390. As co-catalyst triethyl-aluminium (TEAL) and as donor dicyclo pentyl dimethoxy silane (D-donor) was used. The aluminium to donor ratio is indicated in table 1.

(36) As additives 0.04 wt. % synthetic hydrotalcite (DHT-4A supplied by Kisuma Chemicals, Netherlands) and 0.15 wt % Irganox B 215 (1:2-blend of Irganox 1010 (Pentaerythrityl-tetrakis(3-(3,5-di-tert.butyl-4-hydroxytoluyl)-propionate and tris(2,4-di-t-butylphenyl)phosphate) phosphite) of BASF AG, Germany were added to the polymers in the same step. For the production of 1 liter round bottles like used for testing in the inventive work a Fischer Mller Blow Molding Machine was used. The main processing parameters for the production are as follows: Temperature profile: 180 to 200 C. applied in extruder, adapter and head Melt temperature measured: 190 to 200 C. Speed of extruder (revolution per minute; rpm): 13 to 16 rpm Die gap: the die gap was adjusted to get a bottle with a weight of 40 g with Borealis grade RB307MO (random propylene copolymer with a density of 902 kg/m.sup.3 and a MFR.sub.2 of 1.5 g/10 min) Cycle time: 12 to 16 seconds

(37) TABLE-US-00001 TABLE 1 Polymerization conditions CE1 CE2 CE3 TEAL/D [mol/mol] 15 15 15 Loop MFR.sub.2 [g/10 min] 2.7 0.9 1.3 C2 content [wt.-%] 1.7 2.1 1.8 XCS [wt.-%] 5.3 5.0 6.4 C2/C3 ratio [mol/kmol] 3.5 3.4 3.2 1 GPR MFR.sub.2 [g/10 min] 3.7 1.0 1.0 C2 content [wt.-%] 2.1 4.9 5.4 XCS [wt.-%] 4.7 4.7 13.7 C2/C3 ratio [mol/kmol] 16 20 36 2 GPR MFR.sub.2 [g/10 min] 1.8 1.0 1.3 C2 content [wt.-%] 10.5 12.3 11.8 XCS [wt.-%] 29 35 33 C2 of XCS [wt.-%] 28.0 29.0 27.0 IV of XCS [dl/g] 2.6 2.2 2.0 C2/C3 ratio [mol/kmol] 306 319 303 3 GPR MFR.sub.2 [g/10 min] 1.2 1.2 1.3 C2 content [wt.-%] 13.9 13.9 13.0 XCS [wt.-%] 41 41 38 C2 of XCS [wt.-%] 30.0 30.0 28.0 IV of XCS [dl/g] 2.6 2.2 2.0 Tm [ C.] 152 152 150 C2/C3 ratio [mol/kmol] 309 314 296 split loop [wt.-%] 28.6 23.6 24.4 split GPR1 [wt.-%] 36.4 35.4 33.6 split [wt.-%] 35 41 42 (GPR2 + GPR3) C2 content [wt.-%] 2.4 6.8 8.0 produced in GPR1 XCS produced [wt.-%] 4.2 4.5 19.0 in GPR1 C2 content [wt.-%] 35.8 26.9 23.5 produced in GPR2 + GPR3 CE4 CE5 E1 E2 TEAL/D [mol/mol] 15 15 15 15 Loop MFR.sub.2 [g/10 min] 2.3 1.5 1.0 1.2 C2 content [wt.-%] 2.4 2.4 2.4 2.3 XCS [wt.-%] 6.8 6.8 8.5 6.2 C2/C3 ratio [mol/kmol] 3.2 3.7 3.1 3.2 1 GPR MFR.sub.2 [g/10 min] 1.7 1.5 0.7 0.8 C2 content [wt.-%] 6.1 2.4 8.2 8.6 XCS [wt.-%] 18.4 4.9 39 34 C2/C3 ratio [mol/kmol] 16 16 85 84 2 GPR MFR.sub.2 [g/10 min] 1.2 1.6 0.9 0.8 C2 content [wt.-%] 10.0 8.9 10.1 11.0 XCS [wt.-%] 36 34 44 46 C2 of XCS [wt.-%] 22.0 19.0 12.0 12.0 IV of XCS [dl/g] 2.6 2.2 2.4 2.3 C2/C3 ratio [mol/kmol] 177 188 145 132 3 GPR MFR.sub.2 [g/10 min] 1.1 1.5 0.8 0.9 C2 content [wt.-%] 9.7 9.4 10.0 11.5 XCS [wt.-%] 37 38 43 47 C2 of XCS [wt.-%] 22.0 20.0 16.0 16.0 IV of XCS [dl/g] 3.0 2.4 2.3 2.3 Tm [ C.] 150 151 153 152 C2/C3 ratio [mol/kmol] 189 178 133 128 split loop [wt.-%] 26.5 27.7 25.8 25.2 split GPR1 [wt.-%] 36.5 35.3 42.2 44.8 split [wt.-%] 37 37 32 30 (GPR2 + GPR3) C2 content [wt.-%] 8.8 2.4 11.8 12.2 produced in GPR1 XCS produced [wt.-%] 26.8 3.4 58 50 in GPR1 C2 content [wt.-%] 15.8 21.3 13.8 18.3 produced in GPR2 + GPR3

(38) TABLE-US-00002 TABLE 1b Polymerization conditions CE4 CE5 E1 E2 TEAL/D [mol/mol] 15 15 15 15 Loop MFR.sub.2 [g/10 min] 2.3 1.5 1.0 1.2 C2 content [wt.-%] 2.4 2.4 2.4 2.3 XCS [wt.-%] 6.8 6.8 8.5 6.2 C2/C3 ratio [mol/kmol] 3.2 3.7 3.1 3.2 1 GPR MFR.sub.2 [g/10 min] 1.7 1.5 0.7 0.8 C2 content [wt.-%] 6.1 2.4 8.2 8.6 XCS [wt.-%] 18.4 4.9 39 34 C2/C3 ratio [mol/kmol] 16 16 85 84 2 GPR MFR.sub.2 [g/10 min] 1.2 1.6 0.9 0.8 C2 content [wt.-%] 10.0 8.9 10.1 11.0 XCS [wt.-%] 36 34 44 46 C2 of XCS [wt.-%] 22.0 19.0 12.0 12.0 IV of XCS [dl/g] 2.6 2.2 2.4 2.3 C2/C3 ratio [mol/kmol] 177 188 145 132 3 GPR MFR.sub.2 [g/10 min] 1.1 1.5 0.8 0.9 C2 content [wt.-%] 9.7 9.4 10.0 11.5 XCS [wt.-%] 37 38 43 47 C2 of XCS [wt.-%] 22.0 20.0 16.0 16.0 IV of XCS [dl/g] 3.0 2.4 2.3 2.3 Tm [ C.] 150 151 153 152 C2/C3 ratio [mol/kmol] 189 178 133 128 split loop [wt.-%] 26.5 27.7 25.8 25.2 split GPR1 [wt.-%] 36.5 35.3 42.2 44.8 split [wt.-%] 37 37 32 30 (GPR2 + GPR3) C2 content [wt.-%] 8.8 2.4 11.8 12.2 produced in GPR1 XCS produced [wt.-%] 26.8 3.4 58 50 in GPR1 C2 content [wt.-%] 15.8 21.3 13.8 18.3 produced in GPR2 + GPR3

(39) TABLE-US-00003 TABLE 2a Properties CE1 CE2 CE3 Flex Modulus [MPa] 439 403 434 C6-Solubles [wt.-%] 11.9 18.5 13.9 Haze b.s. [%] 87 50 44 Haze a.s. [%] 59

(40) TABLE-US-00004 TABLE 2b Properties CE4 CE5 E1 E2 Flex Modulus [MPa] 442 400 289 235 C6-Solubles [wt.-%] 7.9 14.1 8.8 11.4 Haze b.s. [%] 59 36 29 25 Haze a.s. [%] 71 48 42 37

(41) TABLE-US-00005 TABLE 3a Properties on bottles CE1 CE2 CE3 Average of [m] 5.5 5.5 5.5 drop height (23 C.) Average of [m] 5.5 5.5 5.5 drop height (0 C.) Before sterilization Transparency [%] 76 72 76 Haze [%] 88 61 57 Clarity [%] 9 54 50 Tensile modulus [MPa] 447 395 515 After sterilization Transparency [%] 70 66 70 Haze [%] 93 71 64 Clarity [%] 9 53 52 Tensile modulus [MPa] 505 415 457

(42) TABLE-US-00006 TABLE 3b Properties on bottles CE4 CE5 CE6 CE7 E1 E2 Average of [m] 5.5 5.5 3.5 5.5 5.5 drop height (23 C.) Average of [m] 5.5 5.5 3.5 3.0 5.5 drop height (0 C.) Before sterilization Transparency [%] 80 80 92 87 87 Haze [%] 65 49 47 34 40 Clarity [%] 30 56 67 89 47 Tensile modulus [MPa] 442 380 515 279 226 After sterilization Transparency [%] 75 73 90 85 79 Haze [%] 73 56 42 45 48 Clarity [%] 29 61 73 89 43 Tensile modulus [MPa] 473 410 737 473 271 CE6 is the commercial ethylene propylene random copolymer Bormed RB801CF of Borealis AG CE7 is the commercial LDPE Bormed LE6609PH of Borealis AG