Classifications

• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08F—MACROMOLECULAR COMPOUNDS OBTAINED BY REACTIONS ONLY INVOLVING CARBON-TO-CARBON UNSATURATED BONDS
  • C08F110/00—Homopolymers of unsaturated aliphatic hydrocarbons having only one carbon-to-carbon double bond
  • C08F110/04—Monomers containing three or four carbon atoms
  • C08F110/06—Propene
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
  • C08L23/00—Compositions of homopolymers or copolymers of unsaturated aliphatic hydrocarbons having only one carbon-to-carbon double bond; Compositions of derivatives of such polymers
  • C08L23/02—Compositions of homopolymers or copolymers of unsaturated aliphatic hydrocarbons having only one carbon-to-carbon double bond; Compositions of derivatives of such polymers not modified by chemical after-treatment
  • C08L23/10—Homopolymers or copolymers of propene
  • C08L23/12—Polypropene
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
  • C08L2205/00—Polymer mixtures characterised by other features
  • C08L2205/02—Polymer mixtures characterised by other features containing two or more polymers of the same C08L -group
  • C08L2205/025—Polymer mixtures characterised by other features containing two or more polymers of the same C08L -group containing two or more polymers of the same hierarchy C08L, and differing only in parameters such as density, comonomer content, molecular weight, structure

Definitions

• the present disclosure relates to polypropylene homopolymer composition having high molecular weight and high melt strength containing at least two homopolymer fractions having different intrinsic viscosity.
• Propylene homopolymer is widely used in the processing fields of injection, extrusion, tape casting and biaxial stretching due to the tailoring structure thereof.
• the common polypropylene molecular chain is of linear structure, which is unlike amorphous polymers, such as polystyrene PS with a region having property similar to the rubber elasticity in a wide temperature range.
• polystyrene PS with a region having property similar to the rubber elasticity in a wide temperature range.
• polypropylene cannot be thermoformed in a wide temperature range.
• the softening point of polypropylene is close to its melt point.
• the present disclosure is directed to a propylene homopolymer composition
• a propylene homopolymer composition comprising:
• melt strength of the measured according to ISO 16790-2005, at 250°C and applying an acceleration equal to 6 mm/s2 is higher than 0.070 N;
• the fraction soluble in xylene at 25°C measured according to ISO 16 152 - 2005 is comprised between 6.0 wt% and 2.0wt%;
• the intrinsic viscosity (IV) measured in tetrahydronaphthalene at 135 °C ranges from 10.0 to 4.5 dl/g.
• the present disclosure is directed to a propylene homopolymer composition
• a propylene homopolymer composition comprising:
• melting points are present in the DSC thermogram measured according measured according to ISO 11357-3 with heating and cooling rate of 20°C/min,; preferably the lower melting point ranges from 135°C to 150°C;
• the isotactic pentads mmmm % measured with C 13 NMR% as reported in examples section of the description range from 94.5 mol% to 89.0 mol%; preferably from 93.2 mol % to 90.5 mol %; more preferably form 93.0 mol% to 91.0 mol%;
• the fraction soluble in xylene at 25°C measured according to ISO 16 152 - 2005 is comprised between 5.0 wt% and 2.0wt%; preferably comprised between 4.5 wt% and 2.2wt%; more preferably comprised between 3.5 wt% and 2.4 wt%;
• melt strength measured according to ISO 16790-2005 at 250°C and applying an acceleration equal to 6 mm/s 2 is higher than 0.070 N; preferably higher than 0.080 N; more preferably higher than 0.082 N;
• the intrinsic viscosity (IV) measured in tetrahydronaphthalene at 135 °C ranges from 10.0 to 4.5 dl/g; preferably from 9.2 to 5.2 dl/g; more preferably from 8.5 to 5.5 dl/g.
• the propylene homopolymer of the present disclosure is not nucleated.
• melt strength of the homopolymer of the present disclosure is lower than 0.30 N.
• the homopolymer of the present disclosure shows a polydispersity index, PI, measured according to ISO 6721-10 comprised between 4.5 and 7.5; more preferably between 5.0 and 7.2; more preferably from 5.5 to 7.0.
• PI polydispersity index
• the homopolymer of the present disclosure shows a tensile modulus ranging from 2100 MPa to 1100 MPa; preferably from 1800MPa, to 1200 Mpa.
• the homopolymer of the present disclosure shows a charpy impact test at 23°C ranging from 4.0 kJ/m2 to 11.0 kJ/m2; preferably from 4.5 kJ/m2 to 7.5 kJ/m2.
• the ethylene derived units of components A and B are measured with 13C- NMR as reported in examples section.
• the polypropylene homopolymer composition of the present disclosure is characterized by having an high melt strength and an high molecular weight for this reason the homopolymer composition of the present disclosure can be used alone or in blend with other polymers having a lower melt strength in order to increase the latter so that the resulting blend can be used for the production of foam products, biaxial stretching films, thermoforming products and blow molded products.
• fine tuning the ratio of component A) and component B) it is also possible to finetuning the intrinsic viscosity and the melt strength of the composition.
• the propylene homopolymer composition of the present disclosure can be prepared by a process comprising polymerizing propylene optionally with ethylene, in the presence of Ziegler- Natta catalysts in two reactors connected in series.
• An essential component of said catalysts is a solid catalyst component comprising a titanium compound having at least one titanium-halogen bond, and an electron-donor compound, both supported on a magnesium halide in active form.
• Another essential component (co-catalyst) is an organoaluminium compound, such as an aluminium alkyl compound.
• An external donor is optionally added.
• Catalysts having the above mentioned characteristics are well known in the patent literature; particularly advantageous are the catalysts described in US patent 4,399,054 and European patent 45977. Other examples can be found in US patent 4,472,524.
• the solid catalyst components used in said catalysts comprise, as electron-donors (internal donors), compounds selected from the group consisting of ethers, ketones, lactones, compounds containing N, P and/or S atoms, and esters of mono- and dicarboxylic acids.
• Particularly suitable electron- donor compounds are esters of phtalic acid and 1,3- diethers of formula:
• RI and RII are the same or different and are Cl -Cl 8 alkyl, C3-C18 cycloalkyl or C7-C18 aryl radicals; RIII and RIV are the same or different and are C1-C4 alkyl radicals; or are the 1,3-diethers in which the carbon atom in position 2 belongs to a cyclic or polycyclic structure made up of 5, 6, or 7 carbon atoms, or of 5-n or 6-n' carbon atoms, and respectively n nitrogen atoms and n' heteroatoms selected from the group consisting of N, O, S and Si, where n is 1 or 2 and n' is 1, 2, or 3, said structure containing two or three unsaturations (cyclopolyenic structure), and optionally being condensed with other cyclic structures, or substituted with one or more substituents selected from the group consisting of linear or branched alkyl radicals; cycloalkyl, aryl, aralkyl, al
• diethers are 2-methyl-2-isopropyl-l,3- dimethoxypropane, 2,2-diisobutyl-l,3-dimethoxypropane, 2-isopropyl-2-cyclopentyl-l,3- dimethoxypropane, 2-isopropyl-2-isoamyl- 1,3 -dimethoxypropane, 9,9-bis (methoxymethyl) fluorene.
• Suitable electron-donor compounds are phthalic acid esters, such as diisobutyl, dioctyl, diphenyl and benzylbutyl phthalate.
• a MgC12»nROH adduct (in particular in the form of spheroidal particles) wherein n is generally from 1 to 3 and ROH is ethanol, butanol or isobutanol, is reacted with an excess of TiC14 containing the electron-donor compound.
• the reaction temperature is generally from 80 to 120° C.
• the solid is then isolated and reacted once more with TiC14, in the presence or absence of the electron-donor compound, after which it is separated and washed with aliquots of a hydrocarbon until all chlorine ions have disappeared.
• the titanium compound expressed as Ti
• the quantity of electron-donor compound which remains fixed on the solid catalyst component generally is 5 to 20% by moles with respect to the magnesium dihalide.
• the titanium compounds, which can be used for the preparation of the solid catalyst component are the halides and the halogen alcoholates of titanium. Titanium tetrachloride is the preferred compound.
• the Al-alkyl compounds used as co-catalysts comprise the Al-trialkyls, such as Al- triethyl, Al-triisobutyl, Al-tri-n-butyl, and linear or cyclic Al-alkyl compounds containing two or more Al atoms bonded to each other by way of O or N atoms, or SO4 or SO3 groups.
• Al-trialkyls such as Al- triethyl, Al-triisobutyl, Al-tri-n-butyl, and linear or cyclic Al-alkyl compounds containing two or more Al atoms bonded to each other by way of O or N atoms, or SO4 or SO3 groups.
• the Al-alkyl compound is generally used in such a quantity that the Al/Ti ratio be from 1 to 1000.
• the electron-donor compounds that can be used as external donors include aromatic acid esters such as alkyl benzoates, and in particular silicon compounds containing at least one Si- OR bond, where R is a hydrocarbon radical.
• silicon compounds are (tert-butyl)2Si(OCH3)2, (cyclohexyl)(methyl)Si (OCH3)2, (cyclopentyl)2Si(OCH3)2 and (phenyl)2Si(OCH3)2 and (1,1,2- trimethylpropyl)Si(OCH3)3.
• 1,3 -diethers having the formulae described above can also be used advantageously. If the internal donor is one of these diethers, the external donors can be omitted.
• the component A) are preferably prepared by using catalysts containing a phthalate as internal donor and (cyclopentyl)2Si(OCH3)2 as outside donor, or the said 1,3-diethers as internal donors.
• the polymerization is generally carried out at temperatures of from 20 to 120°C, preferably of from 40 to 80°C.
• the operating pressure is generally between 0.5 and 5 MPa, preferably between 1 and 4 MPa.
• the operating pressure is generally between 1 and 8 MPa, preferably between 1.5 and 5 MPa.
• Hydrogen is typically used as a molecular weight regulator.
• the polymerization can be in gas phase or in slurry or in solution. In one or more reactors. Preferably the polymerizaiotn is carried put in two slurry reactors operating in series, by varying the hydrogen concentration in the two reactors.
• the propylene homopolymer composition of the present disclosure can be used for obtaining fibers, film, molded articles and foamed articles.
• Xylene Solubles fraction has been measured according to ISO 16 152 - 2005; with solution volume of 250 ml, precipitation at 25°C for 20 minutes, 10 of which with the solution in agitation (magnetic stirrer), and drying at 70°.
• Tm melting points of the polymers
• the weighted sample was sealed into aluminium pans and heated to 200°C at 20°C/minute.
• the sample was kept at 200°C for 2 minutes to allow a complete melting of all the crystallites, then cooled to 5°C at 20°C/minute.
• the sample was heated for the second run time to 200°C at 20°C/min. In this second heating run, the peak temperature (Tp,m) was taken as the melting temperature.
• the tacticity of Propylene sequences was calculated as mm content from the ratio of the PPP mmTpp (28.90-29.65 ppm) and the whole Tpp (29.80-28.37 ppm).
• Intrinsic viscosity The sample is dissolved by tetrahydronaphthalene at 135 °C and then it is poured into the capillary viscometer.
• the viscometer tube Ubbelohde type
• the viscometer tube is surrounded by a cylindrical glass jacket; this setup allows temperature control with a circulating thermostated liquid.
• the downward passage of the meniscus is timed by a photoelectric device.
• the passage of the meniscus in front of the upper lamp starts the counter which has a quartz crystal oscillator.
• One single polymer solution is used to determine [r
• the melt strength is measured according to ISO 16790-2005, by Haul-off Melt Strength Meter produced by Geottfert MaschinenstoffPruefmaschinen, Germany.
• This system measures the extensional properties of polymer melts by drawing a vertical melt strand at a constant pull-off speed or with a linear or exponentially accelerating velocity.
• the HAUL-OFF system measures the force needed to elongate the strand, and calculates elongation stress, draw ratio and apparent elongation rate and viscosity.
• Polymer is melt and plasticized through a capillary rheometer, then is extruded from a hole die with a 1 mm of diameter, 30 mm of length and 180° inlet angle. The test is performed at 250°C.
• the distance from the capillary outlet to the center of the transducer pulley is 150 mm.
• the monofilament is stretched at each temperature test applying an acceleration equal to 6 mm/s 2 and, passing through an angular transducer, its tension is measured.
• the draw ratio (dimensionless value) and force (cN) values are recorded as the final result in addition to the entire curve.
• the value of the melt strength is considered the maximum force value of the curve.
• Tensile Modulus is measured according to ISO 527-2, and ISO 1873-2 on compression sample
• the solid catalyst used in the following examples was prepared according to the Example 10 of the International Patent Application WO 00/63261.
• Tri ethylaluminium (TEAL) was used as co-catalyst and dicyclopentyldimethoxysilane as external donor, with the weight ratios indicated in Table 1.
• the polymerization run is carried out in continuous mode in a series of two reactors equipped with devices to transfer the product from one reactor to the one immediately next to it.
• the two reactors are liquid phase loop reactors.
• Propylene is the solvent, hydrogen is used as molecular weight regulator.
• the gas phase (propylene, ethylene and hydrogen) is continuously analyzed via gaschromatography.
• Comparative example 2 is HP556E a propylene homopolymer sold by LyondellBasell.

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• 2023
  • 2023-09-19 WO PCT/EP2023/075837 patent/WO2024099628A1/en not_active Ceased
  • 2023-09-19 EP EP23773273.0A patent/EP4615887A1/de active Pending
  • 2023-09-19 CN CN202380071196.0A patent/CN119998340A/zh active Pending

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