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
  • C08F236/00—Copolymers of compounds having one or more unsaturated aliphatic radicals, at least one having two or more carbon-to-carbon double bonds
  • C08F236/02—Copolymers of compounds having one or more unsaturated aliphatic radicals, at least one having two or more carbon-to-carbon double bonds the radical having only two carbon-to-carbon double bonds
  • C08F236/04—Copolymers of compounds having one or more unsaturated aliphatic radicals, at least one having two or more carbon-to-carbon double bonds the radical having only two carbon-to-carbon double bonds conjugated
  • C08F236/08—Isoprene
• • 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
  • C08F210/00—Copolymers of unsaturated aliphatic hydrocarbons having only one carbon-to-carbon double bond
  • C08F210/02—Ethene
• • 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
  • C08F236/00—Copolymers of compounds having one or more unsaturated aliphatic radicals, at least one having two or more carbon-to-carbon double bonds
  • C08F236/02—Copolymers of compounds having one or more unsaturated aliphatic radicals, at least one having two or more carbon-to-carbon double bonds the radical having only two carbon-to-carbon double bonds
  • C08F236/04—Copolymers of compounds having one or more unsaturated aliphatic radicals, at least one having two or more carbon-to-carbon double bonds the radical having only two carbon-to-carbon double bonds conjugated
  • C08F236/06—Butadiene
• • 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
  • C08F2420/00—Metallocene catalysts
  • C08F2420/01—Cp or analog bridged to a non-Cp X neutral donor

Definitions

• Preformed catalyst system comprising a rare earth metallocene
• the present invention relates to a preformed catalytic system based on rare earth metallocenes, particularly useful in the polymerization of monomers such as conjugated dienes, ethylene, ⁇ -monoolefins and mixtures thereof.
• the invention also relates to a process for preparing said catalytic system, as well as its use in the synthesis of polymers.
• the catalytic systems based on rare earth metallocenes are known: they are for example described in patent applications EP 1 092 731, WO 2004035639 and WO 2007054224 in the name of the Applicants for use in the polymerization of monomers such as conjugated dienes ethylene and ⁇ -monoolefins.
• a catalytic system based on a rare earth metallocene having a stability of the catalytic activity improved storage which solves the problems encountered mentioned above.
• the catalytic system according to the invention has the particularity of being a catalytic system of "preformed" type.
• a first subject of the invention is a catalytic system based at least on:
• Y denoting a group comprising a metal atom which is a rare earth, Cp 1 and Cp 2 , which are identical or different, being chosen from the group consisting of fluorenyl groups, cyclopentadienyl groups and indenyl groups, the groups being substituted or unsubstituted substituted,
• P being a group bridging the two groups Cp 1 and Cp 2 , and comprising a silicon or carbon atom.
• the invention also relates to a process for preparing the catalytic system according to the invention.
• the invention also relates to a process for the preparation of a polymer which comprises the polymerization of a monomer in the presence of the catalytic system according to the invention.
• any range of values designated by the expression “between a and b” represents the range of values greater than “a” and less than “b” (that is, say, bounds a and b excluded) while any range of values designated by the term “from a to b” means the range of values from “a” to "b” (i.e. including strict limits a and b).
• metallocene by means an organometallic complex in which the metal, in this case the rare earth atom, is bound to a ligand molecule consists of two groups Cp 1 and Cp 2 interconnected by a bridge P These groups Cp 1 and Cp 2 , which are identical or different, are chosen from the group consisting of fluorenyl groups, cyclopentadienyl groups and indenyl groups, these groups possibly being substituted or unsubstituted.
• the catalytic system according to the invention has the essential characteristic of being a preformed catalyst from isoprene.
• the preforming monomer useful for the purposes of the invention is isoprene.
• the preforming monomer is preferably used in a molar ratio (preforming monomer / metallocene metal) ranging from 5 to 1000, preferably from 10 to 500.
• the metallocene used as basic constituent in the catalytic system according to the invention corresponds to formula (I)
• Y denotes a group having a metal atom which is a rare earth metal
• Cp 1 and Cp 2 are identical or different, are selected from the group consisting of fluorenyl groups, cyclopentadienyl groups, indenyl groups, the groups being substituted or unsubstituted substituted,
• P is a group bridging the two groups Cp 1 and Cp 2 , and comprising a silicon or carbon atom.
• substituted cyclopentadienyl, fluorenyl and indenyl groups mention may be made of those substituted with alkyl radicals having 1 to 6 carbon atoms or with aryl radicals having 6 to 12 carbon atoms or else with trialkylsilyl radicals such as SiMe 3 .
• the choice of radicals is also oriented by accessibility to the corresponding molecules that are cyclopentadienes, fluorenes and substituted indenes, because they are commercially available or easily synthesizable.
• substituted fluorenyl groups there may be mentioned particularly 2,7-ditertiobutyl-fluorenyl, 3,6-ditertiobutyl-fluorenyl.
• the positions 2, 3, 6 and 7 respectively designate the position of the carbon atoms of the rings as shown in the diagram below, the position 9 corresponding to the carbon atom to which the P bridge is attached.
• Position 2 denotes the position of the carbon atom which is adjacent to the carbon atom to which bridge P is attached, as shown in the diagram below.
• Position 2 denotes the position of the carbon atom which is adjacent to the carbon atom to which bridge P is attached, as shown in the diagram below.
• Cp 1 and Cp 2 are identical and are chosen from the group consisting of substituted fluorenyl groups and the unsubstituted fluorenyl group of formula Ci 3 H 8 .
• the catalytic system has the particularity of producing copolymers of butadiene and ethylene which additionally comprise monomeric units ethylene and butadiene units of 1,2-cyclohexane cyclic units of the following formula:
• Cp 1 and Cp 2 are identical and each represents an unsubstituted fluorenyl group of formula Ci 3 H 8 , represented by the symbol Flu.
• the symbol Y represents the group Met-G, with Met denoting a metal atom which is a rare earth and with G denoting a group comprising the borohydride unit BH 4 or denoting a hydrogen atom.
• halogen X selected from the group consisting of chlorine, fluorine, bromine and iodine.
• G denotes chlorine or the group of formula (II):
• L represents an alkali metal selected from the group consisting of lithium, sodium and potassium,
• N represents a molecule of an ether
• x integer or not, is equal to or greater than 0,
• Ether is any ether which has the ability to complex the alkali metal, including diethyl ether and tetrahydrofuran.
• the metallocene metal useful in the invention is preferably a lanthanide whose atomic number ranges from 57 to 71, more preferably neodymium, Nd.
• the bridge P linking the Cp 1 and Cp 2 groups preferably corresponds to the formula ZR 1 R 2 , in which Z represents a silicon or carbon atom, R 1 and R 2 , which may be identical or different, each represent an alkyl group comprising from 1 to 20 carbon atoms, preferably methyl.
• Z preferably denotes a silicon atom, Si.
• the metallocene is dimethylsilyl bis-fluorenyl neodymium borohydride of formula (III):
• Another basic constituent of the catalytic system according to the invention is the cocatalyst capable of activating the metallocene with respect to the polymerization, in particular in the polymerization initiation reaction.
• the cocatalyst is well known an organometallic compound. Suitable organometallic compounds capable of activating the metallocene, such as organomagnesium, organoaluminum and organolithium compounds.
• the cocatalyst is preferably an organomagnesium compound, that is to say a compound which has at least one C-Mg bond.
• organomagnesium compounds mention may be made of diorganomagnesiums, in particular dialkylmagnesians and organomagnesium halides, in particular alkylmagnesium halides.
• the diorganomagnesium compound has two C-Mg bonds, in this case C-Mg-C; the organomagnesium halide has a C-Mg bond.
• the cocatalyst is a diorganomagnesian.
• the cocatalyst is an organometallic compound comprising an alkyl group bonded to the metal atom.
• a cocatalyst also known as an alkylating agent, alkyl magnesium (also called alkyl magnesium), especially dialkyl magnesium (also called dialkyl magnesium) or alkyl magnesium halide (also known as alkyl magnesium halide), are particularly suitable. butyloctylmagnesium and butylmagnesium chloride.
• the cocatalyst is advantageously butyloctylmagnesium.
• the cocatalyst is used in a molar ratio (cocatalyst / metallocene metal) of preferably from 0.5 to 20, more preferably from 1 to 10.
• the catalytic system preferably comprises a hydrocarbon solvent.
• the catalyst system may be in the form of a solution when it is in the presence of a hydrocarbon solvent.
• the hydrocarbon solvent may be aliphatic such as methylcyclohexane or aromatic such as toluene.
• the hydrocarbon solvent is preferably aliphatic, more preferably methylcyclohexane.
• the catalyst system is stored as a solution in the hydrocarbon solvent before being used in polymerization. One can speak then of catalytic solution which includes the catalytic system and the hydrocarbon solvent.
• the concentration of metallocene metal has a value ranging preferably from 0.0001 to 0.08 mol / l, more preferentially from 0.001 to 0.05 mol / l.
• Another object of the invention is the preparation of the catalytic system described above.
• the process for preparing the catalytic system according to the invention comprises the following steps a) and b):
• the metallocene used for the preparation of the catalyst system can be in the form of crystallized or non-crystalline powder or in the form of single crystals.
• the metallocene may be in a monomeric or dimer form, these forms depending on the mode of preparation of the metallocene, as for example that is described in the application WO 2007054224 A2.
• the metallocene can be prepared in a conventional manner by a process analogous to that described in documents EP I 092 731, WO 2007054223 and WO 2007054224, in particular by reaction under an inert and anhydrous conditions of the alkali metal salt of the ligand with a salt.
• rare earth element such as a halide or a rare earth borohydride
• a suitable solvent such as an ether, such as diethyl ether or tetrahydrofuran or any other solvent known to those skilled in the art.
• the metallocene is separated from the reaction by-products by techniques known to those skilled in the art, such as filtration or precipitation in a second solvent.
• the metallocene is finally dried and isolated in solid form.
• Step a) corresponds to the activation step, commonly also called alkylation, of the metallocene by the cocatalyst;
• step b) corresponds to the preforming step of the catalytic system.
• the hydrocarbon solvent used in the preparation of the catalytic system is generally an aliphatic hydrocarbon solvent such as methylcyclohexane or aromatic such as toluene. Most often, it is identical to the solvent of the catalytic solution defined above. Indeed, the hydrocarbon solvent used in the preparation of the catalytic system is preferably also the solvent of the catalytic solution.
• step a) the hydrocarbon solvent is generally added the cocatalyst and then the metallocene.
• Stage a) generally takes place at a temperature ranging from 20 to 80 ° C.
• the reaction time of step a) is preferably between 5 and 60 minutes, more preferably between 10 and 20 minutes.
• Step b) is generally carried out at a temperature ranging from 40 to 150 ° C., preferably from 40 to 90 ° C.
• the reaction time of step b) typically varies from 0.5 hours to 24 hours, preferably from 1 to 12 hours.
• the preforming monomer is added to the reaction product of step a).
• Step b) may be followed by a degassing step c) to remove unreacted preform monomer in step b).
• Step a) is generally conducted with stirring.
• the catalyst system thus obtained in solution may be stored under an inert atmosphere, for example under nitrogen or argon, in particular at a temperature ranging from -20 ° C. to room temperature (23 ° C.) .
• Another object of the invention is a process for the preparation of a polymer which comprises the polymerization of a monomer M in the presence of the catalytic system according to the invention.
• the monomer M is to be distinguished from the preforming monomer used in the preparation of the catalytic system in step b): the monomer M may or may not be identical to the monomer used in step b).
• the monomer M is preferably selected from the group of monomers consisting of conjugated dienes, ethylene, ⁇ -monoolefins and mixtures thereof.
• Conjugated dienes are particularly suitable 1,3-dienes preferably having from 4 to 8 carbon atoms, especially 1,3-butadiene and isoprene.
• the monomer M is a 1,3-diene having preferably 4 to 8 carbon atoms, in particular 1,3-butadiene or isoprene, or a mixture of 1,3-butadiene and 'ethylene.
• the polymer may be an elastomer.
• the polymerization is preferably carried out in solution, continuously or batchwise.
• the polymerization solvent may be a hydrocarbon, aromatic or aliphatic solvent.
• a polymerization solvent mention may be made of toluene and methylcyclohexane.
• the monomer M may be introduced into the reactor containing the polymerization solvent and the catalytic system, or conversely the catalytic system may be introduced into the reactor containing the polymerization solvent and the monomer M. Alternatively, the monomer M and the catalytic system may be introduced simultaneously into the reactor containing the polymerization solvent, particularly in the case of a continuous polymerization.
• the polymerization is typically conducted under anhydrous conditions and in the absence of oxygen, optionally in the presence of an inert gas.
• the polymerization temperature generally varies in a range from 40 to 150.degree. C., preferably from 40 to 120.degree. It is adjusted according to the monomer M to be polymerized.
• the polymerization can be stopped by cooling the polymerization medium.
• the polymer may be recovered according to conventional techniques known to those skilled in the art, for example by precipitation, by evaporation of the solvent under reduced pressure or by stripping with water vapor.
• Size Exclusion Chromatography is used to separate macromolecules in solution by size through columns filled with a porous gel. The macromolecules are separated according to their hydrodynamic volume, the larger ones being eluted first.
• the SEC allows to apprehend the distribution of the molar masses of a polymer.
• the apparatus used is a "WATERS alliance" chromatograph.
• the elution solvent is tetrahydrofuran, the flow rate 0.7 ml / min, the system temperature 35 ° C and the analysis time 90 min.
• a set of four WATERS columns in series, trade names "STYRAGEL HMW7", “STYRAGEL HMW6E” and two “STYRAGEL HT6E” are used.
• the injected volume of the solution of the polymer sample is 100 ⁇ l.
• the detector is a differential refractometer "WATERS 2410" and the chromatographic data exploitation software is the “WATERS EMPOWER” system.
• the average molar masses calculated relate to a calibration curve made from commercial standard polystyrene "PSS READY CAL-KIT".
• the preforming monomer, isoprene is introduced into the reactor in the proportions indicated in Table I.
• the preforming reaction proceeds at a temperature indicated in Table I, for a period also indicated in Table I.
• the metallocene can be prepared according to the procedure described in the patent application WO 2007054224.
• the catalytic system CE1-1 not according to the invention is prepared according to the method disclosed in the patent application WO 2007054224 and described below:
• the catalytic system CE1-2 not in accordance with the invention is prepared in a manner similar to the catalytic system CE1-1 with the exception of the solvent which is methylcyclohexane.
• the catalytic system CE1-3 not according to the invention is prepared according to the following procedure:
• the catalytic systems CE1-1, CE1-2 and CE1-3 are not in accordance with the invention because of the absence of the preforming step (step b))) These are catalytic systems known to the state of the technique, in particular from the patent application WO 2007054224.
• the catalytic systems CE1-1, CE1-2 are formed "in situ”: in other words the activation reaction takes place directly in the solvent which will take the place of the solvent of polymerization, the monomers to be polymerized are then added to the polymerization solvent containing the catalytic system formed in situ.
• the constituents of the catalytic system CE1-3 are mixed in the presence of a solvent in which the activation reaction takes place to form a catalytic solution with 0.01 mol / L in metallocene, it is this catalytic solution which is added to the polymerization solvent.
• This catalytic solution does not contain any pre-forming monomers.
• bottles hermetically sealed under nitrogen containing the catalytic systems Cl, C4 and C5 are also stored at 23 ° C.
• the catalytic systems CE1-1 and CE1-2 not in accordance with the invention are not stored and are used immediately for polymer synthesis to determine their catalytic activity.
• the catalytic system CE1-3 not according to the invention if it is not used immediately in the polymer synthesis, is stored immediately after its preparation in bottles sealed under a nitrogen atmosphere at 23 ° C.
• the catalytic systems Cl, C4, C5 and CE1-3 are used in polymerization without having been stored after their synthesis or after having been stored at ambient temperature (23 ° C.) for varying periods of time.
• the catalytic activities of the catalytic systems Cl, C4, C5 and CE1-3 are determined, according to whether they have been stored or not, under the polymerization conditions described below.
• the polymerization is carried out at 80 ° C. and at an initial pressure of 4 bar in a 500 ml glass reactor containing 300 ml of polymerization solvent, methylcyclohexane, the catalytic system (47 ⁇ of neodymium metal) and the monomers, the 1,3-butadiene monomers and ethylene being introduced in the form of a gas mixture containing 20 mol% of 1,3-butadiene. All the tests were carried out with a total BOMAG content of 5 molar equivalents relative to neodymium, which led for some tests to a further addition of BOMAG in the reactor at the same time as the catalytic system.
• the polymerization reaction is stopped by cooling, degassing the reactor and adding 10 ml of ethanol. An antioxidant is added to the polymer solution.
• the copolymer is recovered by drying in a vacuum oven. The weighed mass makes it possible to determine the average catalytic activity of the catalytic system expressed in kilograms of copolymer synthesized per mole of neodymium metal and per hour (kg / mol.h). The results of catalytic activity according to the time and storage temperature of the catalyst system in solution are shown in Table III.
• the catalytic activities of the catalytic systems Cl, C4 and C5, preformed with isoprene are similar before or after storage for at least 20 days.
• the catalytic system CE1-3 not in accordance with the invention does not exhibit a catalytic activity as stable at storage at 23 ° C. as the catalytic systems according to the invention.
• the catalytic system CE1-3 exhibits a catalytic decay of more than 20% after only 10 days of storage at 23 ° C.
• Maintaining the catalytic activity over a long period makes it possible to use a single production batch of a catalytic system according to the invention over this same period without having to proceed with readjustment phases of the process parameters of the invention. polymerization and stability of the polymerization tool during this period, while ensuring the specifications of the polymer to be synthesized.
• the catalytic systems according to the invention and the catalytic systems not according to the invention are each used in the polymerization of a mixture of ethylene and 1,3-butadiene according to the procedure described below.
• the polymerization is carried out at 80 ° C. and at an initial pressure of 4 bar in a 500 ml glass reactor containing 300 ml of polymerization solvent, methylcyclohexane or toluene, the catalytic system (47 ⁇ of neodymium metal) and the monomers, 1,3-butadiene monomers and ethylene being introduced in the form of a gas mixture containing 20 mol% of 1,3-butadiene. All the tests were carried out with a total BOMAG content of 5 molar equivalents relative to neodymium, which led for some tests to a further addition of BOMAG in the reactor at the same time as the catalytic system.
• the polymerization reaction is stopped by cooling, degassing the reactor and adding 10 ml of ethanol. An antioxidant is added to the polymer solution.
• the copolymer is recovered by drying in a vacuum oven. The weighed mass makes it possible to determine the average catalytic activity of the catalytic system expressed in kilograms of copolymer synthesized per mole of neodymium metal and per hour (kg / mol.h). The average catalytic activities calculated for each of the catalyst systems are shown in Tables III and IV.
• Examples 15 to 20 and PI to P6 are in accordance with the invention since they implement a catalytic system according to the invention (C1 to C9).
• Examples 13 and 14 and P7 to P9 are not in accordance with the invention because they implement a catalytic system of the state of the art (CE1-1, CE1-2 and CE1-3).
• the catalytic activity of the catalytic systems C1 to C8 is at least equal to or greater than that of the catalytic system of the state of the art (CE1-1 or CE1 - 2).
• the catalytic activity of the catalyst systems according to the invention determined in Examples PI to P5 and Examples 15, 17, 19 is up to 50% greater than that of the non-compliant CE1-2 catalytic system determined in the example P8.
• the catalytic systems in accordance with the invention can be synthesized both as an aromatic solvent (toluene, Examples 9) and as an aliphatic solvent (methylcyclohexane, Example 1) without affecting their catalytic activity.
• the catalytic activity of C9 (Example P6) is comparable to that of Cl synthesized in an aliphatic hydrocarbon solvent, methylcyclohexane (Example 15).

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• 2016
  • 2016-07-25 FR FR1657102A patent/FR3054221A1/fr not_active Withdrawn
• 2017
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