POLYPROPYLENE PIPE COMPOSITION

Abstract

Polypropylene composition having a melting temperature Tm of 135° C. to 140° C. (DSC according to ISO 11357/part 3), —an MFR.sub.2 of 0.05 to 0.50 g/10 min (2.16 kg, 230° C., IS01133), a XS according to IS016152 of 0.2 to 2.5 wt.-%, and a molecular weight distribution Mw/Mn of at least 2.8 and less than 6.0, wherein Mn is the number average molecular weight and Mw is the weight average molecular weight both being determined by Gel Permeation Chromatography (GPC) according to ISO 16014-4:2003, and ASTM D 6474-99, whereby the polypropylene composition comprises units derived from 1-hexene in an amount of 1.80 wt.-% to 5.0 wt.-%.

Claims

1: Polypropylene composition having: a melting temperature Tm of 135° C. to 140° C. (DSC according to ISO 11357/part 3), an MFR.sub.2 of 0.05 to 0.50 g/10 min (2.16 kg, 230° C., ISO1133), a XS xylene soluble content (XS) according to ISO16152 of 0.2 to 2.5 wt. %, and a molecular weight distribution Mw/Mn of at least 2.8 and less than 6.0, wherein Mn is the number average molecular weight and Mw is the weight average molecular weight both being determined by Gel Permeation Chromatography (GPC) according to ISO 16014-4:2003, and ASTM D 6474-99, whereby the polypropylene composition comprises: units derived from 1-hexene in an amount of 1.80 wt. % to 5.0 wt. %.

2: Polypropylene composition according to claim 1, having a flexural modulus of at least 800 MPa when measured according to ISO 178 using test specimens having a dimension of 80×10×4.0 mm.sup.3 (length×width×thickness) and being prepared by injection molding according to EN ISO 1873-2.

3: Polypropylene composition according to claim 1, whereby the xylene soluble content (XS) is within the range of 0.3 to 1.0 wt. % and wherein the polypropylene composition has a flexural modulus of at least 900 MPa when measured according to ISO 178 using test specimens having a dimension of 80×10×4.0 mm.sup.3 (length×width×thickness) and being prepared by injection molding according to EN ISO 1873-2, whereby the polypropylene composition does not include units derived from ethylene.

4: Polypropylene composition according to claim 1, whereby the polypropylene composition include units derived from ethylene in an amount of 0.1 to 1.0 wt. %.

5: Article comprising the polypropylene composition according to claim 1, whereby the polypropylene composition has a xylene soluble content (XS) within the range of 0.3 to 1.0 wt.-% and wherein the polypropylene composition has a flexural modulus of at least 900 MPa when measured according to ISO 178 using test specimens having a dimension of 80×10×4.0 mm.sup.3 (length×width×thickness) and being prepared by injection molding according to EN ISO 1873-2, and whereby the polypropylene composition does not include units derived from ethylene.

6: Article being a pipe according to claim 6, having: a pipe pressure test stability of at least 2000 h (20° C., 16 MPa) following ISO 1167-1 and -2, and a pipe pressure test stability of at least 2000 h (95° C., 4.5 MPa) following ISO 1167-1 and -2.

7: Process for obtaining a polypropylene composition according to claim 1, by a sequential polymerization process, the process comprising the steps of: (a) introducing a stream of propylene and 1-hexene to a first reactor, so that the ratio of the feed rate of 1-hexene to the feed rate of propylene is from 2.0 to 4.0 mol/kmol; further introducing a stream of catalyst system to the first reactor, whereby the catalyst has the following structure: ##STR00006## wherein: M is zirconium or hafnium; each X independently is a sigma-donor ligand; L is a bridge of formula -(ER.sup.10.sub.2).sub.y—; y is 1 or 2; E is C or Si; each R.sup.10 is independently a C.sub.1-C.sub.20-hydrocarbyl group, tri(C.sub.1-C.sub.20 alkyl)silyl group, C.sub.6-C.sub.20 aryl group, C.sub.7-C.sub.20 arylalkyl group or C.sub.7-C.sub.20 alkylaryl group or L is an alkylene group; R.sup.1 are each independently the same or are different from each other and are a CH.sub.2—R.sup.11 group, with R.sup.11 being H or linear or branched C.sub.1-C.sub.6 alkyl group, C.sub.3-C.sub.8 cycloalkyl group, C.sub.6-C.sub.10 aryl group; R.sup.3, R.sup.4 and R.sup.5 are each independently the same or different from each other and are H or a linear or branched C.sub.1-C.sub.6 alkyl group, C.sub.7-C.sub.20 arylalkyl group, C.sub.7-C.sub.20 alkylaryl group, or C.sub.6-C.sub.20 aryl group with the proviso that if there are four or more R.sup.3, R.sup.4 and R.sup.5 groups different from H present in total, one or more of R.sup.3, R.sup.4 and R.sup.5 is other than tert butyl; R.sup.7 and R.sup.8 are each independently the same or different from each other and are H, a CH.sub.2—R.sup.12 group, with R.sup.12 being H or linear or branched C.sub.1-C.sub.6 alkyl group, SiR.sup.13.sub.3, GeR.sup.13.sub.3, OR.sup.13, SR.sup.13, NR.sup.13.sub.2, wherein: R.sup.13 is a linear or branched C.sub.1-C.sub.6 alkyl group, C.sub.7-C.sub.20 alkylaryl group and C.sub.7-C.sub.20 arylalkyl group or C.sub.6-C.sub.20 aryl group, R.sup.9 are each independently the same or different from each other and are H or a linear or branched C.sub.1-C.sub.6 alkyl group; and R.sup.2 and R.sup.6 all are H; in the presence of cocatalyst system comprising a boron containing cocatalyst and an aluminoxane cocatalyst thereby polymerizing propylene and 1-hexene in the presence of the catalyst system in the first reactor to produce a first intermediate; (b) withdrawing a product stream comprising the first intermediate from the first reactor; (c) transferring the first intermediate (PP1) to a second reactor and further polymerizing in the second reactor the first intermediate (PP1) by feeding further propylene, 1-hexene, and optionally ethylene further in the presence of hydrogen such that the ratio of the concentration of hydrogen to the concentration of propylene is in the range of 0.1 to 0.8 mol/kmol; and further the concentration of 1-hexene to the concentration of propylene is in the range of 3.0 to 6.0 mol/kmol, whereby yielding raw polypropylene composition (PP2), (d) extruding said raw polypropylene composition (PP2) to yield the polypropylene composition.

8: Process according to claim 7, comprising feeding fresh catalyst system only to the first reactor or, if present, only to the prepolymerization reactor.

9: Process according to claim 7, whereby the first intermediate (PP1) has: a melting temperature Tm in the range of 145 to 157° C. (DSC according to ISO 11357/part 3, stabilized), and/or a MFR.sub.2 (ISO1133, 2.16 kg) of 0.30 to 0.80 g/10 min, and/or units derived from 1-hexene in an amount of at least 1.0 wt. %, and/or units derived from 1-hexene in an amount of less than 2.5 wt. %, and/or a XS measured according to ISO16152 of less than 2.0 wt. %, and/or a XS measured according to ISO16152 of more than 0.5 wt. %,

10: Process according to claim 7, whereby the first reactor is a loop reactor and/or the second reactor is a gas phase reactor.

11: Process according to claim 7, whereby a prepolymerization precedes the first polymerization stage taking place in the first reactor.

12: Process according to claim 7, whereby the polymerization is carried out without an external donor.

13: Process according to claim 7, whereby the polypropylene composition (PP2) as obtained directly from the second reactor has fines less than 0.05 wt. %, and/or total volatiles less than 90 ppm (VDA277).

14. (canceled)

15: Polypropylene composition according to claim 1, whereby the xylene soluble content (XS) is within the range of 0.3 to 1.0 wt. %.

16: Article comprising the polypropylene composition according to claim 1, whereby the polypropylene composition has a xylene soluble content (XS) within the range of 1.0 to 2.5 wt.-%. and wherein the polypropylene composition has a flexural modulus of 800 MPa to 900 MPa when measured according to ISO 178 using test specimens having a dimension of 80×10×4.0 mm.sup.3 (length×width×thickness) and being prepared by injection molding according to EN ISO 1873-2, and whereby the polypropylene composition include units derived from ethylene.

17: Article according to claim 16, having: a pipe pressure test stability of at least 2000 h (95° C., 4.5 MPa) following ISO 1167-1 and -2.

Description

DETAILED DESCRIPTION

[0139] In the following particularly preferred embodiments of the present invention are described.

[0140] In a first preferred embodiment the polypropylene composition according to the present invention has [0141] a melting temperature Tm of 136° C. to 140° C. (DSC according to ISO 11357/part 3), [0142] an MFR2 of 0.20 to 0.40 g/10 min (2.16 kg, 230° C., ISO1133), [0143] a XS according to ISO16152 of 0.2 wt.-% to less than 1.0 wt.-%, and [0144] a molecular weight distribution Mw/Mn of at least 3.5 and less than 6.0, wherein Mn is the number average molecular weight and Mw is the weight average molecular weight both being determined by Gel Permeation Chromatography (GPC) according to ISO 16014-4:2003 and ASTM D 6474-99, whereby the polyproyplene composition comprises units derived from 1-hexene in an amount of 2.30 wt.-% to 3.5 wt.-%.

[0145] In this preferred embodiment, the polymeric part of the polypropylene composition preferably includes only units derived from propylene and 1-hexene.

[0146] In a second embodiment the polypropylene composition according to the present invention has [0147] a melting temperature Tm of 137° C. to 140° C. (DSC according to ISO 11357/part 3), [0148] an MFR2 of 0.20 to 0.40 g/10 min (2.16 kg, 230° C., ISO1133), [0149] a XS according to ISO16152 of 1.5 wt.-% to 2.5 wt.-%, and [0150] a molecular weight distribution Mw/Mn of at least 3.5 and less than 6.0, wherein Mn is the number average molecular weight and Mw is the weight average molecular weight both being determined by Gel Permeation Chromatography (GPC) according to ISO 16014-4:2003 and ASTM D 6474-99, whereby the polyproyplene composition comprises units derived from 1-hexene in an amount of 2.30 wt.-% to 3.5 wt.-% and units derived from ethylene in an amount of less than 1.0 wt.-%.

[0151] In a third preferred embodiment the polypropylene composition according to the present invention has [0152] a melting temperature Tm of 136° C. to 140° C. (DSC according to ISO 11357/part 3), [0153] an MFR2 of 0.20 to 0.40 g/10 min (2.16 kg, 230° C., ISO1133), [0154] a XS according to ISO16152 of 0.2 to 1.0 wt.-%, and [0155] a molecular weight distribution Mw/Mn of at least 3.5 and less than 6.0, wherein Mn is the number average molecular weight and Mw is the weight average molecular weight both being determined by Gel Permeation Chromatography (GPC) according to ISO 16014-4:2003 and ASTM D 6474-99, whereby the polyproyplene composition comprises

[0156] units derived from 1-hexene in an amount of 2.30 wt.-% to 3.5 wt.-%. and is obtainable by [0157] (a) introducing a stream of propylene and 1-hexene to a first reactor, so that the ratio of the feed rate of 1-hexene to the feed rate of propylene is from 2.0 to 4.0 mol/kmol; further introducing a stream of catalyst sytem to the first reactor, whereby the catalyst has the following structure

##STR00004## [0158] wherein [0159] M is zirconium or hafnium; [0160] each X independently is a sigma-donor ligand [0161] L is a bridge of formula -(ER.sup.10.sub.2).sub.y—; [0162] y is 1 or 2; [0163] E is C or Si; [0164] each R.sup.10 is independently a C.sub.1-C.sub.20-hydrocarbyl group, tri(C.sub.1-C.sub.20 alkyl)silyl group, C.sub.6-C.sub.20 aryl group, C.sub.7-C.sub.20 arylalkyl group or C.sub.7-C.sub.20 alkylaryl group or L is an alkylene group such as methylene or ethylene; [0165] R.sup.1 are each independently the same or are different from each other and are a CH.sub.2—R.sup.11 group, with R.sup.11 being H or linear or branched C.sub.1-C.sub.6 alkyl group, C.sub.3-C.sub.8 cycloalkyl group, C.sub.6-C.sub.10 aryl group; [0166] R.sup.3, R.sup.4 and R.sup.5 are each independently the same or different from each other and are H or a linear or branched C.sub.1-C.sub.6 alkyl group, C.sub.7-C.sub.20 arylalkyl group, C.sub.7-C.sub.20 alkylaryl group, or C.sub.6-C.sub.20 aryl group with the proviso that if there are four or more R.sup.3, R.sup.4 and R.sup.5 groups different from H present in total, one or more of R.sup.3, R.sup.4 and R.sup.5 is other than tert butyl; [0167] R.sup.7 and R.sup.8 are each independently the same or different from each other and are H, a CH.sub.2—R.sup.12 group, with R.sup.12 being H or linear or branched C.sub.1-C.sub.6 alkyl group, SiR.sup.13.sub.3, GeR.sup.13.sub.3, OR.sup.13, SR.sup.13, NR.sup.13.sub.2, wherein [0168] R.sup.13 is a linear or branched C.sub.1-C.sub.6 alkyl group, C.sub.7-C.sub.20 alkylaryl group and C.sub.7-C.sub.20 arylalkyl group or C.sub.6-C.sub.20 aryl group, [0169] R.sup.9 are each independently the same or different from each other and are H or a linear or branched C.sub.1-C.sub.6 alkyl group; and [0170] R.sup.2 and R.sup.6 all are H; [0171] polymerizing propylene and 1-hexene in the presence of the catalyst system in the first reactor to produce a first intermediate (PP1); [0172] b) withdrawing a product stream comprising the first intermediate from the first reactor [0173] transferrring the first intermediate (PP1) to a second reactor and [0174] c) further polymerizing in the second reactor the first intermediate (PP1) by feeding further propylene, 1-hexene in the presence of hydrogen such that [0175] the ratio of the concentration of hydrogen to the concentration of propylene is in the range of 0.1 to 0.8 mol/kmol; and further [0176] the concentration of 1-hexene to the concentration of propylene is in the range of 3.0 to 6.0 mol/kmol [0177] whereby yielding a raw polypropylene composition (PP2) [0178] d) and extruding said raw polypropylene composition (PP2) into the polypropylene composition.

[0179] This guarantees excellent comonomer distribution.

[0180] In a fourth embodiment the polypropylene composition according to the present invention has [0181] a melting temperature Tm of 137° C. to 140° C. (DSC according to ISO 11357/part 3), [0182] an MFR2 of 0.20 to 0.40 g/10 min (2.16 kg, 230° C., ISO1133), [0183] a XS according to ISO16152 of 1.5 wt.-% to 2.5 wt.-%, and [0184] a molecular weight distribution Mw/Mn of at least 3.5 and less than 6.0, wherein Mn is the number average molecular weight and Mw is the weight average molecular weight both being determined by Gel Permeation Chromatography (GPC) according to ISO 16014-4:2003 and ASTM D 6474-99, whereby the polyproyplene composition comprises units derived from 1-hexene in an amount of 2.30 wt.-% to 3.5 wt.-% and units derived from ethylene in an amount of 0.1 to 1.0 wt.-%.

[0185] and is obtainable by [0186] (a) introducing a stream of propylene and 1-hexene to a first reactor, so that the ratio of the feed rate of 1-hexene to the feed rate of propylene is from 2.0 to 4.0 mol/kmol; further introducing a stream of catalyst sytem to the first reactor, whereby the catalyst has the following structure

##STR00005## [0187] wherein [0188] M is zirconium or hafnium; [0189] each X independently is a sigma-donor ligand [0190] L is a bridge of formula -(ER.sup.10.sub.2).sub.y—; [0191] y is 1 or 2; [0192] E is C or Si; [0193] each R.sup.10 is independently a C.sub.1-C.sub.20-hydrocarbyl group, tri(C.sub.1-C.sub.20 alkyl)silyl group, C.sub.6-C.sub.20 aryl group, C.sub.7-C.sub.20 arylalkyl group or C.sub.7-C.sub.20 alkylaryl group or L is an alkylene group such as methylene or ethylene; [0194] R.sup.1 are each independently the same or are different from each other and are a CH.sub.2—R.sup.11 group, with R.sup.11 being H or linear or branched C.sub.1-C.sub.6 alkyl group, C.sub.3-C.sub.8 cycloalkyl group, C.sub.6-C.sub.10 aryl group; [0195] R.sup.3, R.sup.4 and R.sup.5 are each independently the same or different from each other and are H or a linear or branched C.sub.1-C.sub.6 alkyl group, C.sub.7-C.sub.20 arylalkyl group, C.sub.7-C.sub.20 alkylaryl group, or C.sub.6-C.sub.20 aryl group with the proviso that if there are four or more R.sup.3, R.sup.4 and R.sup.5 groups different from H present in total, one or more of R.sup.3, R.sup.4 and R.sup.5 is other than tert butyl; [0196] R.sup.7 and R.sup.8 are each independently the same or different from each other and are H, a CH.sub.2—R.sup.12 group, with R.sup.12 being H or linear or branched C.sub.1-C.sub.6 alkyl group, SiR.sup.13.sub.3, GeR.sup.13.sub.3, OR.sup.13, SR.sup.13, NR.sup.13.sub.2, wherein [0197] R.sup.13 is a linear or branched C.sub.1-C.sub.6 alkyl group, C.sub.7-C.sub.20 alkylaryl group and C.sub.7-C.sub.20 arylalkyl group or C.sub.6-C.sub.20 aryl group, [0198] R.sup.9 are each independently the same or different from each other and are H or a linear or branched C.sub.1-C.sub.6 alkyl group; and [0199] R.sup.2 and R.sup.6 all are H; [0200] polymerizing propylene and 1-hexene in the presence of the catalyst system in the first reactor to produce a first intermediate (PP1); [0201] b) withdrawing a product stream comprising the first intermediate (PP1) from the first reactor; [0202] c) transferrring the first intermediate (PP1) to a second reactor and further polymerizing in the second reactor the first intermediate (PP1) by feeding further propylene, 1-hexene and ethylene in the presence of hydrogen such that [0203] the ratio of the concentration of hydrogen to the concentration of propylene is in the range of 0.1 to 0.8 mol/kmol; and further [0204] the concentration of 1-hexene to the concentration of propylene is in the range of 3.0 to 6.0 mol/kmol [0205] whereby yielding a raw polypropylene composition (PP2) [0206] d) and further extruding said raw polypropylene composition (PP2) into the polypropylene composition.

[0207] As regards the process in general the propylene composition is produced in a sequential polymerization process comprising at least two polymerization zones operating at different conditions to produce the propylene composition. The polymerization zones may operate in slurry, solution, or gas phase conditions or their combinations. Suitable processes are disclosed, among others, in WO-A-98/58976, EP-A-887380 and WO-A-98/58977.

[0208] The catalyst may be transferred into the polymerization zone by any means known in the art. It is thus possible to suspend the catalyst in a diluent and maintain it as homogeneous slurry. Especially preferred it is to use oil having a viscosity from 20 to 1500 mPa-s as diluent, as disclosed in WO-A-2006/063771. It is also possible to mix the catalyst with a viscous mixture of grease and oil and feed the resultant paste into the polymerization zone. Further still, it is possible to let the catalyst settle and introduce portions of thus obtained catalyst mud into the polymerization zone in a manner disclosed, for instance, in EP-A-428054.

[0209] The polymerization in gas phase may be conducted in a fluidized bed reactor, in a fast fluidized bed reactor or in a settled bed reactor or in any combination of these. When a combination of reactors is used then the polymer is transferred from one polymerization reactor to another. Furthermore, a part or whole of the polymer from a polymerization stage may be returned into a prior polymerization stage.

[0210] In a preferred embodiment, the prepolymerization is conducted in a continuous manner as bulk slurry polymerization in liquid propylene, i.e. the liquid phase mainly comprises propylene, with minor amount of other reactants and optionally inert components dissolved therein. Preferably the prepolymerization is conducted in a continuous stirred tank reactor or a loop reactor.

[0211] The prepolymerization reaction is typically conducted at a temperature of 0 to 40° C., preferably from 10 to 30° C., and more preferably from 15 to 25° C.

[0212] The pressure in the prepolymerization reactor is not critical but must be sufficiently high to maintain the reaction mixture in liquid phase. Thus, the pressure may be from 20 to 100 bar, for example 30 to 70 bar.

[0213] The reaction conditions are well known in the art as disclosed, among others, in GB 1580635.

[0214] In the prepolymerization step it is also possible to feed comonomers into the prepolymerization stage.

[0215] In average, the amount of prepolymer on the catalyst is preferably from 10 to 1000 g per g of the solid catalyst component, more preferably is from 50 to 500 g per g of the solid catalyst component.

[0216] As the person skilled in the art knows, the catalyst particles recovered from a continuous stirred prepolymerization reactor do not all contain the same amount of prepolymer. Instead, each particle has its own characteristic amount which depends on the residence time of that particle in the prepolymerization reactor. As some particles remain in the reactor for a relatively long time and some for a relatively short time, then also the amount of prepolymer on different particles is different and some individual particles may contain an amount of prepolymer which is outside the above limits. However, the average amount of prepolymer on the catalyst is preferably within the limits specified above. The amount of prepolymer is known in the art, among others, from GB 1580635.

[0217] It is possible to add other components also to the prepolymerization stage. Thus, hydrogen may be added into the prepolymerization stage to control the molecular weight of the prepolymer as is known in the art. Further, antistatic additive may be used to prevent the particles from adhering to each other or the walls of the reactor as disclosed in WO-A-00/66640.

[0218] The polymerization in the first polymerization zone may be conducted in slurry. Then the polymer particles formed in the polymerization, together with the catalyst fragmented and dispersed within the particles, are suspended in the fluid hydrocarbon. The slurry is agitated to enable the transfer of reactants from the fluid into the particles.

[0219] Slurry polymerization is preferably a so called bulk polymerization. By “bulk polymerization” is meant a process where the polymerization is conducted in a liquid monomer essentially in the absence of an inert diluent. However, as it is known to a person skilled in the art the monomers used in commercial production are never pure but always contain aliphatic hydrocarbons as impurities. For instance, the propylene monomer may contain up to 5% of propane as an impurity. As propylene is consumed in the reaction and also recycled from the reaction effluent back to the polymerization, the inert components tend to accumulate, and thus the reaction medium may comprise up to 40 wt-% of other compounds than monomer. It is to be understood, however, that such a polymerization process is still within the meaning of “bulk polymerization”, as defined above.

[0220] The temperature in the slurry polymerization is typically from 50 to 110° C., preferably from 60 to 100° C. and in particular from 65 to 95° C. The pressure is from 1 to 150 bar, preferably from 10 to 100 bar. In some cases it may be preferred to conduct the polymerization at a temperature which is higher than the critical temperature of the fluid mixture constituting the reaction phase and at a pressure which is higher than the critical pressure of said fluid mixture. Such reaction conditions are often referred to as “supercritical conditions”. The phrase “supercritical fluid” is used to denote a fluid or fluid mixture at a temperature and pressure exceeding the critical temperature and pressure of said fluid or fluid mixture.

[0221] The slurry polymerization may be conducted in any known reactor used for slurry polymerization. Such reactors include a continuous stirred tank reactor and a loop reactor. It is especially preferred to conduct the polymerization in loop reactor. In such reactors the slurry is circulated with a high velocity along a closed pipe by using a circulation pump. Loop reactors are generally known in the art and examples are given, for instance, in U.S. Pat. Nos. 4,582,816, 3,405,109, 3,324,093, EP-A-479186 and U.S. Pat. No. 5,391,654.

[0222] The slurry may be withdrawn from the reactor either continuously or intermittently. A preferred way of intermittent withdrawal is the use of settling legs where the solids concentration of the slurry is allowed to increase before withdrawing a batch of the concentrated slurry from the reactor. The use of settling legs is disclosed, among others, in U.S. Pat. Nos. 3,374,211, 3,242,150 and EP-A-1310295. Continuous withdrawal is disclosed, among others, in EP-A-891990, EP-A-1415999, EP-A-1591460 and EP-A-1860125. The continuous withdrawal may be combined with a suitable concentration method, as disclosed in EP-A-1860125 and EP-A-1591460.

[0223] Into the slurry polymerization stage other components may also be introduced as it is known in the art.

[0224] Process additives may also be introduced into the reactor to facilitate a stable operation of the process.

[0225] When the slurry polymerization stage is followed by a gas phase polymerization stage it is preferred to conduct the slurry directly into the gas phase polymerization zone without a flash step between the stages. This kind of direct feed is described in EP-A-887379, EP-A-887380, EP-A-887381 and EP-A-991684.

[0226] Typically the polymer is extruded and pelletized. The extrusion may be conducted in the manner generally known in the art, preferably in a twin screw extruder. One example of suitable twin screw extruders is a co-rotating twin screw extruder. Those are manufactured, among others, by Coperion or Japan Steel Works. Another example is a counter-rotating twin screw extruder. Such extruders are manufactured, among others, by Kobe Steel and Japan Steel Works.

[0227] The extruders typically include a melting section where the polymer is melted and a mixing section where the polymer melt is homogenised. Melting and homogenisation are achieved by introducing energy into the polymer. The more energy is introduced into the polymer the better homogenisation effect is achieved. However, too high energy incorporation causes the polymer to degrade and the mechanical properties to deteriorate. Suitable level of specific energy input (SEI) is from about 200 to about 450 kWh/ton polymer, preferably from 240 to 350 kWh/ton.

[0228] Typical average residence time of the polymer in the extruder is from about 30 seconds to about 10 minutes. This figure depends to some extent on the type of the extruder. However, for most extruder types values from 1 minute to 5 minutes result in a good combination between homogeneity and mechanical properties of the polymer.

[0229] Suitable extrusion methods have been disclosed, among others, in EP-A-1600276 and WO-A-98/15591.

[0230] Before the extrusion the desired additives are mixed with the polymer. Examples of such additives are, among others, antioxidants, process stabilizers, UV-stabilizers, pigments, fillers, antistatic additives, antiblock agents, nucleating agents and acid scavengers.

[0231] Suitable antioxidants and stabilizers are, for instance, 2,6-di-tert-butyl-p-cresol, tetrakis-[methylene-3-(3′,5-di-tert-butyl-4′hydroxyphenyl)propionate]methane, octadecyl-3-3(3′5′-di-tert-butyl-4′-hydroxyphenyl)propionate, dilaurylthiodipropionate, distearylthiodipropionate, tris-(nonylphenyl)phosphate, distearyl-pentaerythritol-diphosphite and tetrakis(2,4-di-tert-butylphenyl)-4,4′-biphenylene-diphosphonite.

[0232] Some hindered phenols are sold under the trade names of Irganox 1076 and Irganox 1010. Commercially available blends of antioxidants and process stabilizers are also available, such as Irganox B225 marketed by Ciba-Geigy. Suitable acid scavengers are, for instance, metal stearates, such as calcium stearate and zinc stearate. They are used in amounts generally known in the art, typically from 500 ppm to 10000 ppm and preferably from 500 to 5000 ppm.

Experimental

[0233] Measurement Methods

[0234] Al and Zr Determination (ICP-Method)

[0235] The elementary analysis of a catalyst was performed by taking a solid sample of mass, M, cooling over dry ice. Samples were diluted up to a known volume, V, by dissolving in nitric acid (HNO.sub.3, 65%, 5% of V) and freshly deionised (DI) water (5% of V). The solution was then added to hydrofluoric acid (HF, 40%, 3% of V), diluted with DI water up to the final volume, V, and left to stabilise for two hours. The analysis was run at room temperature using a Thermo Elemental iCAP 6300 Inductively Coupled Plasma-Optical Emmision Spectrometer (ICP-OES) which was calibrated using a blank (a solution of 5% HNO.sub.3, 3% HF in DI water), and 6 standards of 0.5 ppm, 1 ppm, 10 ppm, 50 ppm, 100 ppm and 300 ppm of Al, with 0.5 ppm, 1 ppm, 5 ppm, 20 ppm, 50 ppm and 100 ppm of Hf and Zr in solutions of 5% HNO3, 3% HF in DI water.

[0236] Immediately before analysis the calibration is ‘resloped’ using the blank and 100 ppm Al, 50 ppm Hf, Zr standard, a quality control sample (20 ppm Al, 5 ppm Hf, Zr in a solution of 5% HNO3, 3% HF in DI water) is run to confirm the reslope. The QC sample is also run after every 5th sample and at the end of a scheduled analysis set.

[0237] The content of hafnium was monitored using the 282.022 nm and 339.980 nm lines and the content for zirconium using 339.198 nm line. The content of aluminium was monitored via the 167.079 nm line, when Al concentration in ICP sample was between 0-10 ppm (calibrated only to 100 ppm) and via the 396.152 nm line for Al concentrations above 10 ppm.

[0238] The reported values are an average of three successive aliquots taken from the same sample and are related back to the original catalyst by inputting the original mass of sample and the dilution volume into the software.

[0239] In the case of analysing the elemental composition of prepolymerized catalysts, the polymeric portion is digested by ashing in such a way that the elements can be freely dissolved by the acids. The total content is calculated to correspond to the weight % for the prepolymerized catalyst.

[0240] GPC: Molecular weight averages, molecular weight distribution, and polydispersity index (M.sub.n, M.sub.w, M.sub.w/M.sub.n)

[0241] Molecular weight averages (Mw, 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 16014-4:2003 and ASTM D 6474-99.

[0242] A PolymerChar GPC instrument, equipped with infrared (IR) detector was used with 3× Olexis and 1× Olexis Guard columns from Polymer Laboratories and 1,2,4-trichlorobenzene (TCB, stabilized with 250 mg/L 2,6-Di tert butyl-4-methyl-phenol) as solvent at 160° C. and at a constant flow rate of 1 mL/min. 200 μL of sample solution were injected per analysis. The column set was calibrated using universal calibration (according to ISO 16014-2:2003) with at least 15 narrow MWD polystyrene (PS) standards in the range of 0.5 kg/mol to 11 500 kg/mol. Mark Houwink constants for PS, PE and PP used are as described per ASTM D 6474-99. All samples were prepared by dissolving 5.0-9.0 mg of polymer in 8 mL (at 160° C.) of stabilized TCB (same as mobile phase) for 2.5 hours for PP or 3 hours for PE at max. 160° C. under continuous gentle shaking in the autosampler of the GPC instrument

[0243] Quantification of Copolymer Microstructure by NMR Spectroscopy

[0244] Comonomer Content (Ethylene)

[0245] Quantitative .sup.13C {.sup.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 .sup.1H and .sup.13C respectively. All spectra were recorded using a .sup.13C optimised 10 mm extended temperature probehead 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.sub.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.

[0246] 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 .sup.13C {.sup.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.

[0247] 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.

[0248] 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.

[0249] 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 {.sup.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.

[0250] Comonomer Content (1-Hexene)

[0251] 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.

[0252] 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.

[0253] Characteristic signals corresponding to the incorporation of 1-hexene were observed and the comonomer content quantified in the following way.

[0254] 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

[0255] 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

[0256] 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

[0257] The total 1-hexene content was calculated based on the sum of isolated and consecutively incorporated 1-hexene:

Htotal=H+HH

[0258] When no sites indicative of consecutive incorporation observed the total 1-hexeen comonomer content was calculated solely on this quantity:

Htotal=H

[0259] Characteristic signals indicative of regio 2,1-erythro defects were observed (Resconi, L., Cavallo, L., Fait, A., Piemontesi, F., Chem. Rev. 2000, 100, 1253).

[0260] 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.

[0261] The total amount of secondary (2,1-erythro) inserted propene was quantified based on the αα21e9 methylene site at 42.4 ppm:

P21=Iαα21e9

[0262] 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

[0263] 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

[0264] This simplifies to:

Ptotal=I.sub.Sαα+3*Iαα21e9+0.5*IαB4

[0265] The total mole fraction of 1-hexene in the polymer was then calculated as:

fH=Htotal/(Htotal+Ptotal)

[0266] 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))

[0267] This simplifies to:

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

[0268] The total comonomer incorporation of 1-hexene in mole percent was calculated from the mole fraction in the usual manner:

H[mol %]=100*fH

[0269] 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))

[0270] Density

[0271] Density is measured according to ISO 1183-187. Sample preparation is done by compression moulding in accordance with ISO 1872-2:2007.

[0272] DSC Analysis, Melting Temperature (Tm) and Crystallization Temperature (Tc):

[0273] measured with a TA Instrument Q2000 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.

[0274] Crystallization temperature and heat of crystallization (Hc) are determined from the cooling step, while melting temperature and heat of fusion (Hf) are determined from the second heating step.

[0275] Xylene Cold Soluble (XCS) Content

[0276] The xylene soluble (XS) fraction as defined and described in the present invention is determined in line with ISO 16152 as follows: 2.0 g of the polymer were dissolved in 250 ml p-xylene at 135° C. under agitation. After 30 minutes, the solution was allowed to cool for 15 minutes at ambient temperature and then allowed to settle for 30 minutes at 25+/−0.5° C. The solution was filtered with filter paper into two 100 ml flasks. The solution from the first 100 ml vessel was evaporated in nitrogen flow and the residue dried under vacuum at 90° C. until constant weight is reached. The xylene soluble fraction (percent) can then be determined as follows: XS %=(100.Math.m.Math.Vo)/(mo-v); mo=initial polymer amount (g); m=weight of residue (g); Vo=initial volume (ml); v=volume of analysed sample (ml).

[0277] Melt Flow Rate (MFR)

[0278] The melt flow rate (MFR) or melt index (MI) is measured according to ISO 1133. Where different loads can be used, the load is normally indicated as the subscript, for instance, MFR.sub.2 which indicates 2.16 kg load. The temperature is selected according to ISO 1133 for the specific polymer, for instance, 230° C. for polypropylene. Thus, for polypropylene MFR.sub.2 is measured at 230° C. temperature and under 2.16 kg load.

[0279] Flexural Modulus

[0280] The flexural modulus is determined according to ISO 178. The test specimens have a dimension of 80×10×4.0 mm.sup.3 (length×width×thickness) and are prepared by injection molding according to EN ISO 1873-2. The length of the span between the supports: 64 mm. The test speed: 2 mm/min. Force: 100 N.

[0281] Notched Impact Strength (NIS)

[0282] The Charpy notched impact strength (NIS) was measured according to ISO 179 1eA at +23° C., using injection moulded bar test specimens of 80×10×4 mm.sup.3 prepared in accordance with EN ISO 1873-2.

[0283] Pipe Pressure Test

[0284] The pressure test performance of pipes produced from two inventive compositions and one comparative composition was tested in accordance with ISO 1167-1 and -2. The pipes having a diameter of 32 mm and a wall thickness of 3 mm were produced in accordance with ISO 1167-2 on a conventional pipe extrusion line, then subjected to a circumferential (hoop) stress of 16 MPa at a temperature of 20° C. in a water-in-water setup in accordance with ISO 1167-1. The time in hours to failure was registered, times with an addition “still running” meaning that the failure time had not yet been reached at the time of filing of the present patent application.

[0285] Catalyst Activity

[0286] The catalyst activity was calculated on the basis of following formula:

[00001]$\mathrm{Catalyst}.Math..Math.\mathrm{Activity}.Math..Math.\left(\mathrm{kg}.Math.\text{-}.Math.\mathrm{PP}.Math.\text{/}.Math.g.Math.\text{-}.Math.\mathrm{Cat}.Math.\text{/}.Math.h\right).Math.=\frac{\mathrm{amount}.Math..Math.\mathrm{of}.Math..Math.\mathrm{polymer}.Math..Math.\mathrm{produced}.Math..Math.\left(\mathrm{kg}\right)}{\mathrm{catalyst}.Math..Math.\mathrm{loading}.Math..Math.\left(g\right)\times \mathrm{polymerisation}.Math..Math.\mathrm{time}.Math..Math.\left(h\right)}$

[0287] Productivity

[0288] Overall productivity was calculated as

[00002]$\mathrm{Catalyst}.Math..Math.\mathrm{Productivity}.Math..Math.\left(\mathrm{kg}.Math.\text{-}.Math.\mathrm{PP}.Math.\text{/}.Math.g\right)=\frac{\mathrm{amount}.Math..Math.\mathrm{of}.Math..Math.\mathrm{polymer}.Math..Math.\mathrm{produced}.Math..Math.\left(\mathrm{kg}\right)}{\mathrm{catalyst}.Math..Math.\mathrm{loading}.Math..Math.\left(g\right)}$

[0289] For both the catalyst activity and the productivity the catalyst loading is either the grams of prepolymerized catalyst or the grams of metallocene present in that amount of prepolymerized catalyst.

[0290] Prepolymerization Degree (DP): Weight of Polymer/Weight of Solid Catalyst Before Prepolymerization Step

[0291] The composition of the catalysts (before the off-line prepolymerization step) has been determined by ICP as described above. The metallocene content of the prepolymerized catalysts has been calculated from the ICP data as follows:

[00003]$\begin{array}{cc}.Math.\frac{\mathrm{Al}}{\mathrm{Zr}}.Math.\left(\mathrm{mol}.Math.\text{/}.Math.\mathrm{mol}\right)=\frac{\mathrm{Al}\left(\mathrm{wt}.Math..Math.\%,\mathrm{ICP}\right)/2.Math.6,98}{\mathrm{Zr}\left(\mathrm{wt}.Math..Math.\%,\mathrm{ICP}\right)/9.Math.1,2.Math.2},& \mathrm{Equation}.Math..Math.1\\ .Math.\mathrm{Zr}\left(\mathrm{mol}.Math..Math.\%\right)=\frac{1.Math.0.Math.0}{\frac{\mathrm{Al}}{\mathrm{Zr}}.Math.\left(\mathrm{mol}.Math.\text{/}.Math.\mathrm{mol}\right)+1}& \mathrm{Equation}.Math..Math.2\\ \mathrm{MC}\left(\mathrm{wt}.Math..Math.\%,\mathrm{unprepol}..Math.\mathrm{cat}\right)=\frac{1.Math.0.Math.0\times \left(\mathrm{Zr},\mathrm{mol}.Math..Math.\%\times \mathrm{MwMC}\right)}{\begin{array}{c}\mathrm{Zr},\mathrm{mol}.Math..Math.\%\times \mathrm{MwMC}+\\ \left(100-\mathrm{Zr},\mathrm{mol}.Math..Math.\%\right)\times \mathrm{MwMAO}\end{array}}& \mathrm{Equation}.Math..Math.3\\ \mathrm{MC}\left(\mathrm{wt}.Math..Math.\%,\mathrm{prepolymerized}.Math..Math.\mathrm{cat}\right)=\frac{\mathrm{MC}\left(\mathrm{wt}.Math..Math.\%,\mathrm{unprepolymerized}.Math..Math.\mathrm{cat}\right)}{D.Math.P+1}& \mathrm{Equation}.Math..Math.4\end{array}$

[0292] Particle Size

[0293] Particle size distribution was measured in accordance with ISO 13320-1 with a Coulter LS 200 particle size analyzer. The instrument is able to measure the particle size distribution in a range of 0.4-2000 μm. The method is a laser diffraction method, where a laser beam is directed at the sample travelling in a flow-through cuvette. n-Heptane was used as the sample fluid.

[0294] The polymer sample was first pre-treated by screening out particles larger than 2 mm. The screened sample was mixed with isopropanol and put in an ultra-sound device in order to separate the particles from each other. The pre-treated sample was then placed in the sample unit and analysed. The result was calculated using a computer program provided with the instrument.

[0295] The PSD index (also called SPAN) is defined by the following equation (3) below:

[00004]$\begin{array}{cc}\mathrm{PSD}.Math..Math.\mathrm{Index}=\frac{d_{9.Math.0}-d_{1.Math.0}}{d_{5.Math.0}}& \left(3\right)\end{array}$

[0296] wherein d.sub.50 (DV50) represents the median volumetric particle diameter, d.sub.90 (Dv90) represents the smallest particle diameter so that 90% of the particles have a smaller diameter than d.sub.90; d.sub.10 (Dv10) represents the smallest particle diameter so that 10% of the particles have a smaller diameter than d.sub.10.

[0297] The following particle size and particle size distribution indicators have been used in the experiments:

[0298] Dv90=the volumetric amount of particle diameter at 90% cumulative size,

[0299] Dv10=the volumetric amount of particle diameter at 10% cumulative size,

[0300] Dv50=the volumetric amount of particle diameter at 50% cumulative size (median volumetric particle size),

SPAN=(Dv90−Dv10)/Dv50.

Examples

[0301] Examples were carried out in the pilot scale. A loop-gas phase reactor set up was used.

[0302] Polymerisation examples are shown in Table 1. Comparative examples were carried out with a Ziegler Natta catalyst, TEAL and donor D. First, 0.1 mol of MgCl2×3 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 TiCl4 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 TiCl4 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.

[0303] The catalyst used in the working examples was 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 WO2015/011135 A1) was prepared as described in WO 2013/007650A1 (metallocene E2 in WO2013/007650 A1).

[0304] Hexene was used as comonomer in all cases and the hexene was fed to the both reactors, loop and gas phase reactor in order to control the desired hexene content for the final product.

[0305] In the working example 3 also ethylene was fed to the gas phase reactor.

TABLE-US-00001 Comparative Comparative Working Working Working Example Example 1 Example 2 Example 1 Example 2 Example 3 Product type PP-r PP-r PP-r PP-r PP-r (hexene) (hexene) (hexene) (hexene) (hexene) Catalyst type ZNPP ZNPP SSC SSC SSC Catalyst WO2015/01 WO2015/01 WO2015/01 TEAL TEAL 1135, 1135, 1135, Catalyst 3 Catalyst 3 Catalyst 3 Co-catalystsys Borate/TEAL Borate/TEAL Borate/TEAL Donor type D D No Donor No Donor No Donor Prepolymerisation reactor Catalyst 1.72 1.69 3.72 3.85 3.55 feed (g/h) external 139 137 0 0 0 Cocatalyst feed (g/t propylene) Donor feed 28 27 0 0 0 (g/t propylene) Al/Ti ratio 199 201 — — — (mol/mol) Al/donor ratio 10 10 — — — (mol/mol) B1 Temp. (° C.) 25.1 25 20 20 20 B1 Press. (kPa) 5500 5500 4791 4765 4792 B1 Residence 0.21 0.21 0.2 0.22 0.2 time (h) B1 Hydrogen 0.330 0.350 0.102 0.102 0.102 feed (g/h) Loop reactor Temperature (° C.) 80 80 75 75 75 Pressure (kPa) 5361 5368 4552 4527 4553 Propylene 136.4 136.5 164.9 164.5 164.9 feed (kg/h) Hexene feed 4.00 4.10 1.10 1.10 1.09 (kg/h) H2/C3 ratio 0.060 0.070 0.020 0.020 0.020 (mol/kmol) C6/C3 ratio 14.6 15.1 3.3 3.3 3.3 (mol/kmol) Residence 0.6 0.61 0.5 0.5 0.5 time (h) Production 31 31.2 34.9 36.8 37.6 rate (kg/h) Polymer 48 50 45 42 42 Split (wt.-%) Catalyst 18 18 9.9 10.1 11.1 productivity (kg/g) Tm (° C.) 160.7 162.1 146.4 149.4 155.4 MFR2 (g/10 min) 0.040 0.06 0.39 0.58 0.51 C6 content (%) 0.3 0.4 1.3 1.2 1.2 XS (%) 1.8 1.7 1.1 1.2 1.3 Average 0.95 0.85 1.2 1.2 1.2 particle size Bulk density 330 321 463 466 472 (kg/m3) GPR reactor Temperature (° C.) 85 85 80 80 80 Pressure (kPa) 2023 2291 2400 2399 2400 Propylene 120 120 210 208 207 feed (kg/h) Hydrogen 34 17 0.7 0.3 0.5 feed (g/h) H2/C3 ratio 10.6 6.9 0.53 0.38 0.63 (mol/kmol) C6/C3 14.2 14.1 4.3 5.2 4.3 concentration ratio (mol/kmol) C2/C3 55.0 concentration ratio (mol/kmol) Residence 1.77 1.86 2.1 2.3 2.2 time (h) Production 34 30 43 39 43 rate (kg/h) Polymer 52 50 55 58 58 Split (wt.-%) Total 600 550 75 72 80 volatiles (PP2) Total catalyst 37.8 36.3 20.8 19.7 22.6 productivity (kg/g) Bulk density 410 361 508 501 531 (kg/m3) Average 1.31 1.14 1.38 1.35 1.51 particle size (mm) (PP2) Fines 1.8 1.9 0.01 0.03 0.03 (wt.-%) (PP2) Final Tm (° C.) 154.5 156.2 139.6 137.9 139.4 Tcr (° C.) 117.9 116.5 103.0 102.4 97.9 MFR.sub.2 (g/10 min; 0.29 0.31 0.31 0.29 0.32 230° C.; 2.16 kg) XS (%) 1.3 1.3 0.79 0.58 1.98 Mw/Mn (GPC) 8.5 — 4.3 4.6 4.4 Total C6 (wt.-%) 1.40 1.30 2.30 2.50 2.80 Total C2 (wt.-%) 0.70 Flexural modulus 1460 — 1013 969 825 NIS Charpy 2.9 7.2 7.6 6.2 (23° C.) NIS Charpy 1.5 2.4 2.1 1.9 (0° C.) NIS Charpy 1.0 2.0 2.1 1.5 (−20° C.) Pipe Pipe impact 10 nd nd test (0° C.) Pipe  23 h  7748 h nd   38 h pressure test 20° C., 16 MPa Pipe 650 h >9900 h nd >9400 h pressure test (still running) (still running) 95° C., 4.5 MPa