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
  • C08F4/00—Polymerisation catalysts
  • C08F4/42—Metals; Metal hydrides; Metallo-organic compounds; Use thereof as catalyst precursors
  • C08F4/44—Metals; Metal hydrides; Metallo-organic compounds; Use thereof as catalyst precursors selected from light metals, zinc, cadmium, mercury, copper, silver, gold, boron, gallium, indium, thallium, rare earths or actinides
  • C08F4/60—Metals; Metal hydrides; Metallo-organic compounds; Use thereof as catalyst precursors selected from light metals, zinc, cadmium, mercury, copper, silver, gold, boron, gallium, indium, thallium, rare earths or actinides together with refractory metals, iron group metals, platinum group metals, manganese, rhenium technetium or compounds thereof
  • C08F4/62—Refractory metals or compounds thereof
  • C08F4/64—Titanium, zirconium, hafnium or compounds thereof
• • 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
  • C07—ORGANIC CHEMISTRY
  • C07F—ACYCLIC, CARBOCYCLIC OR HETEROCYCLIC COMPOUNDS CONTAINING ELEMENTS OTHER THAN CARBON, HYDROGEN, HALOGEN, OXYGEN, NITROGEN, SULFUR, SELENIUM OR TELLURIUM
  • C07F3/00—Compounds containing elements of Groups 2 or 12 of the Periodic Table
  • C07F3/003—Compounds containing elements of Groups 2 or 12 of the Periodic Table without C-Metal linkages
• • 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
  • C08F4/00—Polymerisation catalysts
  • C08F4/42—Metals; Metal hydrides; Metallo-organic compounds; Use thereof as catalyst precursors
  • C08F4/44—Metals; Metal hydrides; Metallo-organic compounds; Use thereof as catalyst precursors selected from light metals, zinc, cadmium, mercury, copper, silver, gold, boron, gallium, indium, thallium, rare earths or actinides
  • C08F4/60—Metals; Metal hydrides; Metallo-organic compounds; Use thereof as catalyst precursors selected from light metals, zinc, cadmium, mercury, copper, silver, gold, boron, gallium, indium, thallium, rare earths or actinides together with refractory metals, iron group metals, platinum group metals, manganese, rhenium technetium or compounds thereof
  • C08F4/62—Refractory metals or compounds thereof
  • C08F4/64—Titanium, zirconium, hafnium or compounds thereof
  • C08F4/65—Pretreating the metal or compound covered by group C08F4/64 before the final contacting with the metal or compound covered by group C08F4/44
  • C08F4/652—Pretreating with metals or metal-containing compounds
  • C08F4/654—Pretreating with metals or metal-containing compounds with magnesium or compounds thereof

Definitions

• the present invention relates to magnesium dichloride/ethanol adducts which are characterized by particular chemical and physical properties.
• the adducts of the present invention are particularly useful as precursors of catalyst components for the polymerization of olefins.
• MgC *alcohol adducts and their use in the preparation of catalyst components for the polymerization of olefins are well known in the art.
• Catalyst components for the polymerization of olefins obtained by reacting MgCb «nEtOH adducts with halogenated transition metal compounds, are described in USP 4,399,054.
• the adducts are prepared by emulsifying the molten adduct in an immiscible dispersing medium and quenching the emulsion in a cooling fluid to collect the adduct in the form of spherical particles. No physical characterization regarding the degree of cristallinity of the adducts are reported.
• Said adducts can be of formula MgCl «mEtOH»nH 2 O where m is between 2.2 and 3.8 and n is between 0.01 and 0.6.
• the above described adducts are characterized by a Differential Scanning Calorimetry (DSC) profile in which no peaks are present at temperatures below 90°C or, even if peaks are present below said temperature, the fusion enthalpy associated with said peaks is less than 30% of the total fusion enthalpy.
• DSC Differential Scanning Calorimetry
• adducts are obtained by specific preparation methods involving the reaction between MgCl 2 and alcohol under conditions such long reaction times and absence of inert diluents or use of vaporized alcohol. None is said, in the working examples, about the water content.
• the catalyst components obtained from these adducts have an increased activity over those obtained from the adducts of the prior art. However, the availability of catalyst components with still improved activity is always needed in view of the economic advantages obtainable in the operation of the industrial plants.
• the applicant has now found new MgCb»mEtOH adducts having specific chemical and physical properties.
• the adducts of the present invention can be used to prepare catalyst components for the polymerization of olefins by reacting them with transition metal compounds. Catalyst components obtained from the adducts of the present invention are capable to give catalysts for the polymerization of olefins characterized by enhanced activity with respect to the catalysts prepared from the adducts of the prior art.
• the present invention therefore relates to MgCb»mEtOH adducts in which m is from 2.5 to 3.2 optionally containing water up to a maximum of l%wt based on the total weight of the adduct, characterized by a DSC diagram (profile) in which the highest melting Temperature (Tm) peak is over 109°C and has an associated fusion enthalpy ( ⁇ H) of 103J/g or lower.
• Tm melting Temperature
• ⁇ H fusion enthalpy
• the water content is lower than 0.8% wt and preferably lower than 0.6%wt.
• the highest melting Temperature (Tm) peak is over 110°C and more preferably over 111°C.
• the fusion enthalpy associated to it is lower than 102 J/g and most preferably in the range 97-101 J/g.
• the adducts showing, in the DSC diagram (profile), only one peak, however, additional peaks in the 95-98°C region may be present.
• the fusion enthalpy associated to them is lower than 30% of the total fusion enthalpy, preferably lower than 20 and more preferably lower than 10%.
• the DSC analysis is carried out using the apparatus and the methodology described hereinafter.
• the adducts of the present invention can be prepared according to several methods, hi particular the general methods described in WO98/44009 .are suitable with the proviso that the amount of water is carefully controlled. A particular attention should be paid to the water content of the reactants. Both MgCb and EtOH are in fact highly hygroscopic and tend to incorporate water in their structure. As a result, if the water content of the reactants is relatively high, the final MgCb- EtOH adducts may contain a too high water content even if water has not been added as a separate component. Means for controlling or lowering the water content in solids or fluids are well known in the art.
• the water content in MgCb can be for example lowered by drying it in an oven at high temperatures or by reacting it with a compound which is reactive towards water.
• a stream of HC1 can be used to remove water from MgCb.
• Water from the fluids can be removed by various techniques such as distillation or by allowing the fluids to become in contact with substances capable to subtract water such as molecular sieves.
• the adducts are prepared by dispersing the particles of magnesium dichloride in an inert liquid immiscible with and chemically inert to the molten adduct, heating the system at temperature equal to or higher than the melting temperature of MgCb»ethanol adduct and then adding the desired amount of alcohol in vapour phase. The temperature is kept at values such that the adduct is completely melted.
• the molten adduct is then emulsified in a liquid medium which is immiscible with and chemically inert to it and then quenched by contacting the adduct with an inert cooling liquid, thereby obtaining the solidification of the adduct.
• the liquid in which the MgCb is dispersed can be any liquid immiscible with and chemically inert to the molten adduct.
• aliphatic, aromatic or cycloaliphatic hydrocarbons can be used as well as silicone oils. Aliphatic hydrocarbons such as vaseline oil are particularly preferred.
• the mixture is heated at temperatures preferably higher than 125°C and more preferably at temperatures higher than 150°C.
• the vaporized alcohol is added at a temperature equal to or lower than the temperature of the mixture.
• the adducts of the invention are prepared by contacting MgCb and alcohol in the absence of the inert liquid dispersant, heating the system at the melting temperature of MgCb-alcohol adduct or above, and maintaining said conditions so as to obtain a completely melted adduct.
• molten adduct is then emulsified in a liquid medium which is immiscible with and chemically inert to it and finally quenched by contacting the adduct with an inert cooling liquid thereby obtaining the solidification of the adduct.
• the adduct is preferably kept at a temperature equal to or higher than its melting temperature, under stirring conditions, for a time period equal to or greater than 10 hours, preferably from 10 to 150 hours, more preferably from 20 to 100 hours.
• a spray-cooling process of the molten adduct can be carried out.
• All these methods provide solid adducts having a spherical morphology which are very suitable in the preparation of spherical catalyst components for the polymerization of olefins and in particular for the gas-phase polymerization process.
• the said catalyst components to be used in the polymerization of olefins can be obtained by a reacting the adducts of the invention and a transition metal compound of one of the groups 4-6 of the Periodic Table of Elements (new notation).
• transition metal compounds particularly preferred are titanium compounds of formula Ti(OR) n X y -n in which n is comprised between 0 and y; y is the valence of titanium; X is halogen and R is an alkyl radical having 1-8 carbon atoms or a COR group.
• particul.arly preferred are titanium compounds having at least one Ti- halogen bond such as titanium tetrahalides or halogenalcoholates.
• Preferred specific tit-mium compounds are TiCl 3 , TiCl 4 , Ti(OBu) , Ti(OBu)Cl 3 , Ti(OBu) 2 Cb, Ti(OBu) 3 Cl.
• the reaction is carried out by suspending the adduct in cold TiC (generally 0°C); then the so obtained mixture is heated up to 80-130°C and kept at this temperature for 0.5-2 hours. After that the excess of TiCl 4 is removed and the solid component is recovered.
• the treatment with TiCl 4 can be carried out one or more times.
• the reaction between transition metal compound and the adduct can also be carried out in the presence of an electron donor compound (internal donor) in particular when the preparation of a stereospecific catalyst for the polymerization of olefins is to be prepared.
• Said electron donor compound can be selected from esters, ethers, amines, silanes and ketones. As a result of this contact the electron donor compound remains deposited on the catalyst component.
• alkyl and aryl esters of mono or polycarboxylic acids such as for example esters of benzoic, phthalic, malonic and succinic acid are preferred.
• Specific examples of such esters are n-butylphthalate, di-isobutylphthalate, di-n-octylphthalate, diethyl 2,2- diisopropylsuccinate, diethyl 2,2-dicyclohexyl-succinate, ethyl-benzoate and p-ethoxy ethyl- benzoate.
• R, R 1 , R ⁇ , R ⁇ , R and R equal or different to each other are hydrogen or hydrocarbon radicals having from 1 to 18 carbon atoms, and R VI and R v ⁇ , equal or different from each other, have the same meaning of R-R except that they cannot be hydrogen; one or more of the R-R groups can be linked to form a cycle.
• the 1,3-di ethers in which R and R are selected from d- C 4 alkyl radicals are particularly preferred.
• the electron donor compound is generally present in molar ratio with respect to the magnesium comprised between 1 :4 and 1 :20.
• the particles of the solid catalyst components have substantially spherical morphology and an average diameter comprised between 5 .and 150 ⁇ m.
• substantial spherical morphology are meant those particles having a ratio between the greater and smaller axis equal to or lower than 1.5 and preferably lower than 1.3.
• the adducts of the present invention can also be subjected to a dealcoholation treatment aimed at lowering the alcohol content and increasing the porosity of the adduct itself.
• the dealcoholation can be carried out according to known methodologies such as those described in EP-A-395083.
• partially dealcoholated adducts can be obtained having an alcohol content generally ranging from 0.1 to 2.6 moles of alcohol per mole of MgCb.
• the adducts are reacted with the transition metal compound, according to the techniques described above, in order to obtain the solid catalyst components.
• the solid catalyst components according to the present invention show a surface area (by B.E.T.
• the catalyst components comprising the reaction product of a transition metal compound with a MgCb-alcohol adduct which is in turn obtained by partially dealcoholating the adducts of the invention, show improved properties, particularly in terms of activity, with respect to the catalyst components prepared from the dealcoholated adducts of the prior art.
• the alkyl-Al compound is preferably chosen among the trialkyl aluminum compounds such as for example triethylaluminum, triisobutylaluminum, tri-n-butylaluminum, tri-n-hexylaluminum, tri-n-octylaluminum.
• alkylaluminum halides alkylaluminum hydrides or alkylaluminum sesquichlorides such as AlEt 2 Cl and AbEt 3 Cl3 optionally in mixture with said trialkyl aluminum compounds.
• the Al/Ti ratio is higher than 1 and is generally comprised between 20 and 800.
• an electron donor compound (external donor) which can be the same or different from the compound used as internal donor can be used in the preparation of the catalysts disclosed above.
• the external donor is preferably selected from the silane compounds containing at least a Si-OR link, having the formula Ra Rb Si(OR ) c , where a and b are integer from 0 to 2, c is an integer from 1 to 3 and
• R , R , and R are alkyl, cycloalkyl or aryl radicals with 1-18 carbon atoms.
• Particularly preferred are the silicon compounds in which a is 1, b is 1, c is 2, at least one of R 1 and R is selected from branched alkyl, cycloalkyl or aryl groups with 3-10 carbon atoms and R is a Ci-Cio alkyl group, in particular methyl.
• Examples of such preferred silicon compounds are methylcyclohexyldimethoxysilane, diphenyldimethoxysilane, methyl-t-butyldimethoxysilane, dicyclopentyldimethoxysilane.
• R is a branched alkyl or cycloalkyl group and R is methyl.
• Examples of such preferred silicon compounds are cyclohexyltrimethoxysilane, t-butyltrimethoxysilane and thexyltrimethoxysilane.
• 1,3 diethers having the previously described formula can be used as external donor.
• R is hydrogen or a hydrocarbon radical having 1-12 carbon atoms.
• the catalysts of the invention can be used in any of the olefin polymerization processes known in the art. They can be used for example in slurry polymerization using as diluent an inert hydrocarbon solvent or bulk polymerization using the liquid monomer (for example propylene) as a reaction medium. Moreover, they can also be used in the polymerization process carried out in gas-phase operating in one or more fluidized or mechanically agitated bed reactors.
• the polymerization is generally carried out at temperature of from 20 to 120°C, preferably of from
• the operating pressure is generally between 0.1 and 10 MPa, preferably between 1 and 5 MPa.
• the bulk polymerization the operating pressure is generally between 1 and 6 MPa preferably between 1.5 and 4 MPa.
• the catalysts of the invention are very useful for preparing a broad range of polyolefin products.
• olefinic polymers which can be prepared are: high density ethylene polymers (HDPE, having a density higher than 0.940 g/cc), comprising ethylene homopolymers and copolymers of ethylene with alpha-olefins having 3-12 carbon atoms; linear low density polyethylenes (LLDPE, having a density lower than 0.940 g/cc) and very low density and ultra low density (NLDPE and ULDPE, having a density lower than 0.920 g/cc, to 0.880 g/cc) consisting of copolymers of ethylene with one or more alpha-olefins having from 3 to 12 carbon atoms, having a mole content of units derived from the ethylene higher than 80%; isotactic polypropylenes and crystalline copolymers of propylene and ethylene and/or other alpha-olefins having a content of units derived from propylene higher than 85% by weight; copolymers of propylene
• the DSC measurement were carried out with a METTLER DSC 30 instrument at a scanning rate of 5°C/min in the range 5-125°C.
• Aluminum capsules having a volume of 40 ⁇ l filled with the samples in a dry-box were used in order to avoid hydration of the samples.
• the DSC profile showed a peak at 110.1°C, with an associated fusion enthalpy of 98.7 J/g. and a peak at 93.3°C, with an associated fusion enthalpy of 20.6 J/g.
• the catalyst component prepared according to the general procedure, was tested according to the general polymerization procedure described above and gave the results reported in Table 1. COMPARISON EXAMPLE 1
• Example 1 The procedure of Example 1 was repeated with the difference that the 115.3 g of ethanol were added with 2.95 g of water.
• the compositional analysis showed that they contained 57.6 % by weight of EtOH and 1.65% of water.
• the DSC profile showed a peak at 105.6°C, with an associated fusion enthalpy of 97.6 J/g and a peak at 76°C °C, with an associated fusion enthalpy of 21.6 J/g.
• the catalyst component, prepared according to the general procedure was tested according to the general polymerization procedure described above and gave the results reported in Table 1.

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• 2003
  • 2003-03-17 KR KR1020037014862A patent/KR100973457B1/ko not_active Expired - Fee Related
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