Low EFO polypropylene composition

Abstract

Polymer composition comprising at least one polypropylene homopolymer and/or random copolymer, up to 15 wt % of at least one polyethylene, optionally at least one elastomer in an amount of 8 to 40 wt % and optionally fillers and/or additives in an amount of up to 45 wt % based on the total weight of the final polymer composition with the at least one polyethylene having a density of higher than 940 kg/m3, a content of hexane hot extractables of below 0.80 wt % preferably below 0.60 wt %, most preferably below 0.40 wt % and a copolymer/homopolymer (COHO) ratio measured by Temperature Rising Elution Fraction (TREF) up to 6%.

Claims

1. A polymer composition comprising: a) one or more of at least one polypropylene homopolymer or random copolymer, b) from 0.1 up to 15 wt % of at least one polyethylene, c) optionally at least one elastomer in an amount of 8 to 40 wt % and d) optionally one or more of fillers or additives in an amount of up to 45 wt % based on the total weight of the final polymer composition with the at least one polyethylene having a density of higher than 940 kg/m.sup.3, a content of hexane hot extractables of below 0.80 wt %, and a copolymer/homopolymer (COHO) ratio measured by Temperature Rising Elution Fraction (TREF) of up to 6%.

2. The polymer composition according to claim 1 comprising: a) one or more of at least one polypropylene homopolymer or random copolymer, b) 5 to 15 wt % of at least one polyethylene having a density of higher than 940 kg/m.sup.3, a content of hexane hot extractables of below 0.80 wt % and a copolymer/homopolymer ratio (COHO ratio) measured by Temperature Rising Elution Fraction (TREF) up to 6%, c) an elastomer in an amount of 10 to 30 wt %, d) up to 30 wt % fillers and e) up to 4 wt % additives, based on the total weight of the final polymer composition.

3. The polymer composition according to claim 1, comprising: a) one or more of at least one polypropylene homopolymer or random copolymer, b) 5 to 15 wt % of at least one polyethylene having a density of higher than 940 kg/m.sup.3, a content of hexane hot extractables of below 0.80 wt % and a copolymer/homopolymer ratio (COHO ratio) measured by Temperature Rising Elution Fraction (TREF) up to 6%, c) an elastomer in an amount of 10 to 30 wt %, d) 5 to 30 wt % talc as a filler and e) up to 4 wt % additives comprising 2 to 3 wt % of a colour masterbatch and 1 wt % of other additives, based on the total weight of the final polymer composition.

4. The polymer composition according to claim 1, wherein the one or more of at least one polypropylene homopolymer or random copolymer has a melt flow rate MFR.sub.2 (230 C.) measured according to ISO 1133 in the range of 1 to 1000 g/10 min.

5. The polymer composition according to claim 1, wherein the content of the xylene cold soluble (XCS) fraction of the one or more of at least one polypropylene homopolymer or random copolymer is in the range of 0.1 to 6 wt %.

6. The polymer composition according to claim 1, wherein the at least one polypropylene has a glass transition temperature (Tg) in the range of 10 to +10 C.

7. The polymer composition according to claim 1, wherein the at least one polyethylene has a molar-mass dispersity DM of 2.5-4.

8. The polymer composition according to claim 1, wherein the at least one polyethylene has a comonomer content of 0 to 0.5 wt % based on the weight of the at least one polyethylene component.

9. The polymer composition according to claim 1, wherein the at least one polyethylene has a MFR.sub.2 (190 C.) measured according to ISO 1133 of 0.2 to 15 g/10 min.

10. The polymer composition according to claim 1, wherein the at least one elastomer has been produced in the polymerization reaction step with ethylene or higher -olefins like C.sub.4 to C.sub.8 being used as comonomers to the one or more of polypropylene homopolymer or random copolymer and wherein a heterophasic copolymer is obtained.

11. The polymer composition according to claim 1, wherein the MFR.sub.2 (230 C.) measured according to ISO 1133 of the polymer composition is in the range of 5-100 g/10 min.

12. The polymer composition according to claim 1, wherein the polymer composition contains up to 1 wt % of a slip agent based on the total weight of the final polymer composition.

13. A method comprising producing polymer compositions with at least one polyethylene, the at least one polyethylene having a density of higher than 940 kg/m.sup.3, a content of hexane hot extractables of below 0.80 wt % and a copolymer/homopolymer (COHO) ratio measured by Temperature Rising Elution Fraction (TREF) of up to 6%, the polymer compositions having a scratch resistance of below 3, an odour value of below 3.5 and a simultaneous increase of the FOG value of not more than 40%, the VOC value of not more than 35% and the Fogging of not more than 300% compared to the polymer matrix material.

14. A method comprising producing articles with reduced EFO with a polymer composition according to claim 1.

15. An article comprising a polymer composition, the polymer composition comprising: a) one or more of at least one polypropylene homopolymer or random copolymer, b) from 0.1 up to 15 wt % of at least one polyethylene, c) optionally at least one elastomer in an amount of 8 to 40 wt % and d) optionally one or more of fillers or additives in an amount of up to 45 wt % based on the total weight of the final polymer composition with the at least one polyethylene having a density of higher than 940 kg/m.sup.3, a content of hexane hot extractables of below 0.80 wt %, and a copolymer/homopolymer (COHO) ratio measured by Temperature Rising Elution Fraction (TREF) of up to 6%.

16. The polymer composition according to claim 1, wherein the content of hexane hot extractables is below 0.60 wt %.

17. The polymer composition according to claim 1, wherein the content of hexane hot extractables is below 0.40 wt %.

18. The method according to claim 13, wherein the at least one polyethylene has a content of hexane hot extractables of below 0.60 wt %.

19. The method according to claim 13, wherein the at least one polyethylene has a content of hexane hot extractables of below 0.40 wt %.

20. The article according to claim 15, wherein the article is an automotive interior or a houseware article.

Description

EXAMPLES

(1) 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.

1. Measuring Methods

(2) Quantification of Microstructure by NMR Spectroscopy

(3) Quantitative nuclear-magnetic resonance (NMR) spectroscopy was used to quantify the comonomer content of the polymers. Quantitative 13C{1H} NMR spectra were recorded in the solution-state, using a Bruker Advance III 400 NMR spectrometer operating at 400.15 and 100.62 MHz for 1H and 13C respectively. All spectra were recorded using a 13C optimised 10 mm extended temperature probe head at 125 C. using nitrogen gas for all pneumatics. Approximately 200 mg of material was dissolved in 3 ml of 1,2-tetrachloroethane-d2 (TCE-d2) along with chromium-(III)-acetylacetonate (Cr(acac)3) resulting in a 65 mM solution of relaxation agent in solvent as described in G. Singh, A. Kothari, V. Gupta, Polymer Testing, 2009, 28(5), 475.

(4) To ensure a homogenous solution, after initial sample preparation in a heat block, the NMR tube was further heated in a rotatory oven for at least 1 hour. Upon insertion into the magnet the tube was spun at 10 Hz. This setup was chosen primarily for the high resolution and quantitatively needed for accurate ethylene content quantification. Standard single-pulse excitation was employed without NOE, using an optimised tip angle, 1 s recycle delay and a bi-level WALTZ16 decoupling scheme as described in Z. Zhou, R. Kuemmerle, X. Qiu, D. Redwine, R. Cong, A. Taha, D. Baugh, B. Winniford, J. Mag. Reson., 187 (2007), 225 and V. Busico, P. Carbonniere, R. Cipullo, C. Pellecchia, J. Severn, G. Talarico, Macromol. Rapid Commun., 2007, 28, 1128. A total of 6144 (6 k) transients were acquired per spectra. Quantitative 13C {1H} NMR spectra were processed, integrated and relevant quantitative properties determined from the integrals. All chemical shifts were indirectly referenced to the central methylene group of the ethylene block (EEE) at 30.00 ppm using the chemical shift of the solvent. This approach allowed comparable referencing even when this structural unit was not present.

(5) With characteristic signals corresponding to 2,1-erythro regio defects observed (as described in L. Resconi, L. Cavallo, A. Fait, F. Piemontesi, Chem. Rev. 2000, 100 (4), 1253, in Cheng, H. N., Macromolecules, 1984, 17, 1950, and in W-J. Wang and S. Zhu, Macromolecules, 2000, 33, 1157) the correction for the influence of the regio defects on determined properties was required. Characteristic signals corresponding to other types of regio defects were not observed.

(6) Characteristic signals corresponding to the incorporation of ethylene were observed (as described in Cheng, H. N., Macromolecules, 1984, 17, 1950) and the comonomer fraction calculated as the fraction of ethylene in the polymer with respect to all monomer in the polymer.

(7) The comonomer fraction was quantified using the method of W-J. Wang and S. Zhu, Macromolecules, 2000, 33, 1157, through integration of multiple signals across the whole spectral region in the .sup.13C{1H} spectra. This method was chosen for its robust nature and ability to account for the presence of regio-defects when needed. Integral regions were slightly adjusted to increase applicability across the whole range of encountered comonomer contents. The mole percent comonomer incorporation was calculated from the mole fraction. The weight percent comonomer incorporation was calculated from the mole fraction.

(8) Comonomer Content in Polyethylene (HDPE)

(9) The comonomer content in polyethylene was measured in a known manner based on Fourier transform infrared spectroscopy (FTIR) calibrated with .sup.13C-NMR, using Nicolet Magna 550 IR spectrometer together with Nicolet Omnic FTIR software.

(10) Films having a thickness of about 250 m were compression moulded from the samples. Similar films were made from calibration samples having a known content of the comonomer. The comonomer content was determined from the spectrum from the wave number range of from 1430 to 1100 cm.sup.1. The absorbance is measured as the height of the peak by selecting the so-called short or long base line or both. The short base line is drawn in about 1410-1320 cm.sup.1 through the minimum points and the long base line about between 1410 and 1220 cm.sup.1. Calibrations need to be done specifically for each base line type. Also, the comonomer content of the unknown sample needs to be within the range of the comonomer contents of the calibration samples.

(11) MFR.sub.2 (230 C.) for Polypropylene:

(12) The melt flow rate is measured as the MFR.sub.2 in accordance with ISO 1133 (230 C., 2.16 kg load) for polypropylene. 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.

(13) MFR.sub.2 (190 C.) for Polyethylene:

(14) The melt flow rate (MFR) is determined according to ISO 1133 (190 C., 2.16 kg load) 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. MFR may be determined at different loadings such as 2.16 kg (MFR.sub.2), 5 kg (MFR.sub.5) or 21.6 kg (MFR.sub.21).

(15) Density for HDPE:

(16) The density of the polymer was measured according to ISO 1183-2. The sample preparation was executed according to ISO 1872-2 Table 3 Q (compression moulding).

(17) Xylene Cold Solubles (XCS, Wt %):

(18) The amount of the polymer soluble in xylene is determined at 25 C. according to ISO 16152; 5.sup.th edition; 2005-07-01.

(19) The Hexane Extractable Fraction:

(20) Hexane extractables were determined according to the following procedure. 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 stilling in a reflux condenser for 4 h. The hot solution was filtered through a folded filter paper and dried (in a vacuum oven at 90 C.) and weighted (0.0001 g exactly) in a round schlenk. 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 schlenk was dried in a vacuum oven at 90 C. overnight and was put into a desiccator for at least 2 hours to cool down. The schlenk was weighted again and the hexane soluble was calculated therefrom.

(21) Melting Temperature (T.sub.m):

(22) measured with a TA Instrument Q200 differential scanning calorimeter (DSC) on 5 to 7 mg samples. DSC is run according to ISO 20 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 (Tc) and crystallization enthalpy (Hc) are determined from the cooling step, while melting temperature (Tm) and melting enthalpy (Hm) are determined from the second heating step respectively from the first heating step.

(23) Glass Transition Temperature Tg:

(24) is determined by dynamic mechanical thermal analysis according to ISO 6721-7. The measurements are done in torsion mode on compression moulded samples (40101 mm) between 100 C. and +150 C. with a heating rate of 2 C./min and a frequency of 1 Hz.

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

(26) Charpy Notched Impact Strength:

(27) Charpy notched impact is measured according to ISO 179/1eA at +23 C. and at 20 C. using an injection moulded test specimen (80104 mm) as produced according to ISO 1873.

(28) Tensile Modulus and Tensile Strength:

(29) The tensile properties were determined according to ISO 527-1 and 2 on injection moulded specimen, type 1B. The injection moulding is performed according to ISO 1873.

(30) Scratch Resistance:

(31) To determine the scratch visibility, a Cross Hatch Cutter Model 420P, manufactured by Erichsen, was used. For the tests, plaques of 70704 mm size were cut from a moulded grained plaque of size 1402004 mm (grain parameters: average grain size=1 mm, grain depth=0.12 mm, conicity=6). The period between injection moulding of specimens and scratch-testing was 7 days.

(32) For testing, the specimens must be clamped in a suitable apparatus as described above. Scratches were applied at a force of 10 N using a cylindrical metal pen with a ball shaped end (radius=0.5 mm0.01). A cutting speed of 1000 mm/min was used.

(33) A minimum of 20 scratches parallel to each other were brought up at a load of 10 N with a distance of 2 mm The application of the scratches was repeated perpendicular to each other, so that the result was a scratching screen. The scratching direction should be unidirectional.

(34) The scratch visibility is reported as the difference of the luminance, L, of the unscratched and the scratched areas. L values were measured using a spectrophotometer that fulfils the requirements to DIN 5033.

(35) A detailed test description of the test method (Erichsen cross hatch cutter method) can be found in the article Evaluation of scratch resistance in multiphase PP blends by Thomas Koch and Doris Machl, published in Polymer Testing, 26 (2007), p. 927-936.

(36) VOC:

(37) determined according to VDA 278:2002 from pellets. VOC according to VDA 278 is the sum of all high and medium volatile compounds. It is calculated as toluene equivalent (TE). VOC according to VDA 278 represents all organic compounds in the boiling point and elution range of up to C20 (n-eicosane).

(38) FOG:

(39) determined according to VDA 278:2002 from pellets. FOG according to VDA 278 is the sum of all organic compounds of low volatility, which have an elution time greater than or equal to n-hexadecane. FOG is calculated as hexadecane equivalent (HD). FOG according to VDA 278 represents organic compounds in the boiling point range of n-alkanes C16 to C32.

(40) VDA standards are issued by Verband der Automobilindustrie. The VDA standards used herein are available from Dokumentation Kraftfahrwesen (DKF); Ulrichstrasse 14, D-74321 Bietigheim-Bissingen, Germany or can be downloaded from their website (www.dkf-ev.de).

(41) Fogging:

(42) Fogging is measured on a 2 mm compression moulded specimen. Fogging means the evaporation of volatiles matters of trim materials of vehicles. The measurements were done on compression moulded specimens (diameter 80 mm+/1 mm, thickness 2 mm) according to ISO 75201, method B. This method evaluates the volatility of organic constituents by gravimetric measurements. The samples were dried at room temperature for 24 h using silica gel in a desiccator. The test was done at 100 C. The beakers have to be closed by using tarred aluminium foils (diameter 103 mm, thickness 0.03 mm) and glass plates and the cooling plates on top. After the testing time (16 h at 100 C.) the glass plates have to be removed (not usefully anymore at this method), the aluminium foils are removed and weighted back. The gravimetric Fogging value G (%) shall be determined by the following equation:
G=weight of aluminium foil after Fogging testtare of the aluminium foil,in mg
G sample=Average in mg of the 2 foils used for each sample
Total Volatiles:

(43) the Total Volatiles value is determined according to VDA 277:1995 from pellets. The Total Volatiles value is the total emission of organic carbon, determined according to the method in VDA 277. This value represents the amount of organic compounds which are emitted by a test sample which compounds can be found in the interior of a car.

(44) Odour:

(45) Odour was determined according to VDA 270:1992 according to variant 3 from pellets with a panel of 7 people.

(46) Evaluation Scale:

(47) Grade 1 not perceptible

(48) Grade 2 perceptible, not disturbing

(49) Grade 3 clearly perceptible, but not disturbing

(50) Grade 4 disturbing

(51) Grade 5 strongly disturbing

(52) Grade 6 not acceptable

(53) Molecular Weight Average and Molecular Weight Distribution (Mn, Mw, Mz, MWD):

(54) Molecular weight averages (M.sub.z, M.sub.w and M.sub.n), molecular weight distribution (MWD) and its broadness, described by its molar-mass dispersity, D.sub.M=M.sub.w/M.sub.n (wherein M.sub.n is the number average molecular weight and M.sub.w 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:

(55) $\begin{array}{cc}{M}_n=\frac{\underset{i=1}{\overset{N}{.Math.}}{A}_i}{\underset{i=1}{\overset{N}{.Math.}}\left(A_i/M_i\right)}& \left(1\right)\\ M_w=\frac{\underset{i=1}{\overset{N}{.Math.}}\left(A_i{\mathrm{xM}}_i\right)}{\underset{i=1}{\overset{N}{.Math.}}{A}_i}& \left(2\right)\\ M_z=\frac{\underset{i=1}{\overset{N}{.Math.}}\left(A_i{\mathrm{xM}}_i^2\right)}{\underset{i=1}{\overset{N}{.Math.}}\left(A_i/M_i\right)}& \left(3\right)\end{array}$

(56) For a constant elution volume interval Vi, 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.

(57) A high temperature GPC instrument, equipped with either infrared (IR) detector (IR4 or IR5) from PolymerChar (Valencia, Spain) or differential refractometer (RI) from Agilent Technologies, equipped with 3 Agilent-PL gel Olexis and 1 Agilent-PL gel 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. and at a constant flow rate of 1 mL/min. 200 L of sample solution was injected per analysis. Data collection was performed using either Agilent Cirrus software, version 3.3, or PolymerChar GPC-IR control software.

(58) 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=1910.sup.3 mL/g,.sub.PS=0.655
K.sub.PE=3910.sup.3 mL/g,.sub.PE=0.725
K.sub.PP=1910.sup.3 mL/g,.sub.PP=0.725

(59) A third order polynomial fit was used to fit the calibration data. All samples were prepared in the concentration range of 0.5-1 mg/ml and dissolved at 160 C. for 2.5 hours for PP or 3 hours for PE under continuous gentle shaking.

(60) TREF Method:

(61) (running with method Standard 180-35 C.): The chemical composition distribution was determined by analytical Temperature Rising Elution fractionation as described by Soares, J. B. P., Fractionation, In: Encyclopaedia Of Polymer Science and Technology, John Wiley & Sons, New York, pp. 75-131, Vol. 10, 2001. The separation of the polymer in TREF is according to their crystallinity in solution. The TREF profiles were generated using a CRYSTAF-TREF 200+ instrument manufactured by PolymerChar S.A. (Valencia, Spain).

(62) The polymer sample was dissolved in 1,2,4-trichlorobenzene (TCB, stabilized with 250 mg/L 2,6-Di tert. butyl-4-methyl-phenol) at a concentration between 1.5 and 2.0 mg/ml at 150 C. for 180 min and 1.8 mL of the sample solution was injected into the column (8 mm inner diameter, 15 cm length, filled with inert e.g. glass beads). The column oven was then rapidly cooled to 110 C. and held at 110 C. for 30 min for stabilization purpose and it was later slowly cooled to 35 C. under a constant cooling rate (0.1 C./min). The polymer was subsequently eluted from the column with 1,2,4-trichlorobenzene (stabilized with 250 mg/L 2,6-di-tert-butyl-4-methyl-phenol) at a flow rate of 0.5 mL/min at 35 C. for a period of 10 min followed by a temperature increase from 35 C. to 135 C. at a constant heating rate of 0.5 C./min with a flow rate of 0.5 ml/min. The concentration of the polymer during elution was recorded by an infrared detector (measuring the CH absorption at 3.5 micrometer wavelength). The detector response was plotted as a function of the temperature. The normalized concentration plot was presented as fractogram together with the cumulative concentration signal normalized to 100.

(63) Definition of Homopolymer (HO) High Crystalline Fraction and Copolymer (CO) Low Crystalline Fraction:

(64) The Homopolymer high crystalline fraction, so called HO fraction (for homopolymer high crystalline fraction) is the amount in wt % of the polymer fraction with elutes between 90 C. and 110 C. elution temperature and which mainly contains the homo-polyethylene chains or chains with a very low branching content.

(65) The Copolymer low crystalline fraction, so called CO fraction (for copolymer low crystalline fraction) is the amount in wt % of the polymer fraction with elutes between 35 C. and 90 C.

(66) The soluble fraction, so called soluble TREF, is the amount in wt % of the polymer with elutes below 35 C.

(67) The copolymer/homopolymer (COHO) ratio (in %) is defined:
COHO=((soluble TREF+CO fraction)/HO fraction)100 (in %)
Median Particle Size d.sub.50 and Cut-Off Particle Size d.sub.95 of Mineral Filler:

(68) is calculated from the particle size distribution [mass percent] as determined by gravitational liquid sedimentation according to ISO 13317-3 (Sedigraph).

(69) Surface Area of Mineral Filler:

(70) BET with N.sub.2 gas according to DIN 66131/2, apparatus Micromeritics Tristar 3000: sample preparation at a temperature of 50 C., 6 hours in vacuum.

2. Examples

(71) TABLE-US-00001 TABLE 1 Polymerization details of PP1 , PP3 and PP4 PP1 PP3 PP4 catalyst Unit cat 1 cat 2 cat 2 Prepoly Temperature C. 20 20 20 Residence time h 0.32 0.32 0.32 Loop Temperature C. 80 75 70 H2/C3 mol/kmol 0.41 0.25 0.26 MFR g/10 min 44.5 28 35 split % 76 68 35 GPR1 Temperature C. 80 70 85 H2/C3 mol/kmol 4.64 2.7 2.4 C2/C3 mol/kmol 0 0 249 Split % 24 32 44 C2 wt % 0 0 3.5 MFR g/10 min 58 36 29 GPR2 Temperature C. n.a. n.a. 80 H2/C3 mol/kmol n.a. n.a. 0 C2/C3 mol/kmol n.a. n.a. 10944 split % n.a. n.a. 21 MFR g/10 min n.a. n.a. 12 Pellets MFR g/10 min 68 49 16 XCS wt % 1.3 1.6 26 IV dg/l n.m. n.m. 1.92 C2 total wt % n.m. n.m. 17.5 C2(XCS) wt % n.m. n.m. 30 Tm C. 149 153 153

(72) Table 1 shows the polymerization details of the polypropylene materials PP1, PP3 and PP4 referred to in Table 2 below. The materials have been polymerized in a multistage process which is a loop-gas phase-process (BORSTAR technology of Borealis). Step 1 (loop) corresponds to a bulk homopolymerization with a loop reactor, step 2 to the first gas phase homopolymerization (GPR1) and step 3 (GPR2) to the second gas phase step, C2/C3 copolymerization. The PP pellets comprise 1500 ppm of B225 (BASF) and 500 ppm of calcium stearate (Ceasit AV-FI Veg, Baerlocher). The catalyst used has been prepared following the general procedures described in WO2013/007650 to prepare catalyst E2P, using the same metallocene complex (E2 in WO2013/007650) rac-anti-dimethylsilanediyl(2-methyl-4-(4-tert-butylphenyl)inden-1-yl)(2-methyl-4-phenyl-5-methoxy-6-tert-butylinden-1-yl) zirconium dichloride. The composition of catalysts 1 and 2 is the following: Al/Zr (molar ratio) in unprepped catalyst: 300 for catalyst 1, 440 for catalyst 2. Degree of prepping (g(PP)/g(cat)) for catalyst 1 and catalyst 2: 3.5.

(73) The final polypropylene compositions were prepared by melt blending the components on a co-rotating twin screw extruder type Coperion ZSK 40 (screw diameter 40 mm, L/D ratio 38) at temperatures in the range of 170190 C., using a high intensity mixing screw configuration with two sets of kneading blocks.

(74) Conventional HDPE is the commercial high density polyethylene (HDPE) BB2581 of Borealis AG the properties of which are shown in Table 3 below. HDPE in the invention is the commercial HDPE SCLAIR IG 464-C of Nova Chemicals the properties of which are shown in table 3 below. Elastomer 1.8 is a commercial product (Engage 8150) from Dow Chemicals with a density of 868 kg/m.sup.3 and a MFR.sub.2 (190 C.) of 0.5 g/10 min.

(75) Elastomer 1.1 is a commercial product (Engage 8100) from Dow Chemicals with a density of 870 kg/m.sup.3 and a MFR.sub.2 (190 C.) of 1 g/10 min Slip agent is (Z)-docos-13-enamide (Erucamide), CAS No. 112-84-5 with the trade name Crodamide ER-BE-(HU), from Croda. Talc 3.9: is the commercial product Luzenac HAR T84, particle size top cut>15 m: <2%, d50 12 m.

(76) $\mathrm{Fogging}=\frac{\mathrm{Fogging}\mathrm{of}\mathrm{blends}-\mathrm{Fogging}\mathrm{of}\mathrm{blank}}{\mathrm{Fogging}\mathrm{of}\mathrm{blank}}100\%$$\mathrm{VOC}=\frac{\mathrm{VOC}\mathrm{of}\mathrm{blends}-\mathrm{VOC}\mathrm{of}\mathrm{blank}}{\mathrm{VOC}\mathrm{of}\mathrm{blank}}100\%$$\mathrm{Fog}=\frac{\mathrm{Fog}\mathrm{of}\mathrm{blends}-\mathrm{Fog}\mathrm{of}\mathrm{blank}}{\mathrm{Fog}\mathrm{of}\mathrm{blank}}100\%,$
with blank referring to materials that do not comprise any PE and/or slip agent.

(77) TABLE-US-00002 TABLE 2 Mechanical properties and EFO values of Polymer composition C.E.3 C.E.4 C.E.6 C.E.1 C.E.2 I.E.1 I.E.2 PP1 = HF SSC Homo/wt % 59.0 52.0 52.0 52.0 PP3 = HF Homo MFR50/wt % 41.5 34.5 34.5 PP4 = PP random copo with 20.0 20.0 20.0 elastomer/wt % Elastomer 1.8/wt % 12.0 12.0 12.0 Elastomer 1.1/wt % 17.0 17.0 17.0 17.0 HDPE conventional/wt % 7.0 7.0 7.0 HDPE of invention/wt % 7.0 7.0 Slip agent/wt % 0.2 0.2 Talc 3.9/wt % 15.0 15.0 15.0 15.0 15.0 15.0 15.0 MFR/g/10 min 17 12 12 28 21 23 29 Impact strength at 23 C./kJ/m.sup.2 6.6 12.6 14.9 5.2 8.9 8.6 8.7 Impact strength at 20 C./kJ/m.sup.2 2.5 2.6 2.6 2.4 2.5 2.5 2.5 Tensile modulus/MPa 1882 1727 1772 2197 2002 2020 1929 Tensile strength/MPa 24 24 23 26 25 25 25 Scratch Delta L 5.09 2.77 0.03 3.26 1.98 2.6 0.14 no HDPE, conventional no HDPE, HDPE of no Slip conventional HDPE + no Slip conventional HDPE of invention + agent HDPE Slip agent agent HDPE invention Slip agent Total emission/gC/g 14 12 12 21 23 22 12 Odour (mean) 4.4 4.4 3.9 3.1 3 3.4 n.m. FOG/gHD/g 50 90 114 84 122 91 88 FOG/% 0 80 128 0 45 8 5 VOC/gTE/g 44 72 62 53 75 51 59 VOC/% 0 64 41 0 42 4 11 Fogging/mg 0.14 0.24 0.43 0.35 1.495 0.52 0.9 Fogging/% 0 71 207 0 327 49 157

(78) TABLE-US-00003 TABLE 3 properties of HDPE used in the invention Invention conventional ZN based ZN based HDPE HDPE SCLAIR Grade BB2581 IG464-C MFR(190/2, 16) (in g/10 min) 0.3 10 Density (in kg/m.sup.3) 0.958 0.964 Comonomer (in wt %) 0.2% (butene) 0 Hot hexane extractable (in %) 1.89 0.26 0.39 0.01 Soluble TREF (in wt %) 2.34 0.6 CO fraction (in wt %) 12.74 4.53 HO fraction (in wt %) 84.92 94.87 COHO (in %) 17.8 5.4

(79) From Table 2, Comparative Examples C.E.3 and C.E.4, respectively C.E.1 and C.E.2 it can be seen that when a conventional ZN based HDPE (BB2581) is added to a PP matrix material, both the FOG, VOC and Fogging values are increased considerably. C.E.6 shows that when a slip agent (e.g. Crodamide ER-BE-(HU)) is added too, the scratch resistance is clearly improved, but although the VOC value is also improved both the FOG and Fogging are tremendously deteriorated. So the slip agent shows an antagonistic effect with the HDPE. When instead of the conventional ZN based HDPE an HDPE with the properties specified in the invention (e.g. SCLAIR IG 464-C from Nova Chemicals) is added to the PP matrix then both the FOG, and Fogging values remain nearly constant; only a minor increase of those values is obtained whereas with regard to VOC even an improvement is achievable (see I.E.1) When a slip agent is added too, there is no deterioration of the FOG value and an acceptable increase of the Fogging value observed, thus in comparison to the use of conventional ZN based HDPE, the HDPE according to the invention shows no antagonistic effect with the slip agent. Compared to the comparative polymer compositions comprising the conventional ZN based polyethylene, the inventive polymer compositions show an increase in the FOG value of not more than 40%, in the VOC of not more than 35% and in Fogging of not more than 300%. Moreover there is no negative impact on the mechanical properties compared to the polypropylene base material shown, so that the inventive polymer composition is perfectly suitable for automotive and household applications.