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
  • C08F10/00—Homopolymers and copolymers of unsaturated aliphatic hydrocarbons having only one carbon-to-carbon double bond
• • 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
  • C08F2410/00—Features related to the catalyst preparation, the catalyst use or to the deactivation of the catalyst
  • C08F2410/06—Catalyst characterized by its size
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
  • Y10S—TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10S526/00—Synthetic resins or natural rubbers -- part of the class 520 series
  • Y10S526/908—Containing catalyst of specified particle size

Definitions

• R is an alkyl radical comprising from 4 to 8 carbon atoms and n is 1.
• organoaluminum chloride is isobutylaluminum dichloride.
• organic oxygenated compounds of magnesium and titanium is intended to denote all the compounds in which any organic radical is linked to the metal via oxygen, that is to say all the compounds comprising at least one sequence of organic radical metal-oxygen bonds per de-metal atom.
• the organic radicals linked to the metal via oxygen are arbitrary. They are preferably chosen from radicals comprising from 1 to 20 carbon atoms and, more particularly, from those comprising from 1 to 10 carbon atoms. The best results are obtained when these radicals contain from 2 to 6 carbon atoms. These radicals can be saturated or unsaturated, branched chain, straight chain or cyclic; they can also be substituted or contain heteroatoms, such as silicon, sulfur, nitrogen or phosphorus, in their chain. They are preferably chosen from hydrocarbon radicals and in particular from alkyl radicals (linear or crossed), alkenyl, aryl, cycloalkyl, arylalkyl, alkylaryl, acyl and their substituted derivatives.
• halogenated compounds of magnesium and titanium is intended to denote all of the compounds comprising a metal-gene link.
• the metal bound halogen can be fluorine, chlorine, bromine or iodine. Of preferably, the halogen is chlorine.
• organic and halogenated oxygenated compounds which are suitable, use is preferably made of those which contain only metal-oxygen-organic radical bonds and / or metal-halogen bonds to the exclusion of any other bond.
• the solid catalytic complexes used in the present invention are prepared from reactants (1) which are magnesium compounds (M).
• the organic oxygenated compounds (M) can comprise, in addition to the organic radicals linked to magnesium via oxygen, other radicals.
• These other radicals are preferably oxygen and the inorganic radicals linked to the metal via oxygen, such as the radicals -OH, - (SO 4 ) 1/2 , NO 3 , (PO 4 ) 1 / 3 , (CO 3 ) 1/2 and -ClO 4 .
• They can also be organic radicals linked directly to magnesium by carbon.
• magnesium compounds containing both a magnesium-halogen bond and an organic radical as defined above linked to magnesium via oxygen is also part of the invention.
• the compounds of this type giving the best results are of course, chlorakloxides and chlorphenoxides such as Mg (OCH 3 ) Cl, Mg (OC 2 H 5 ) Cl and Mg (OC 6 H 5 ) Cl for example.
• the reagents (2) used to prepare the catalytic complexes according to the invention are titanium compounds (T).
• the tetravalent titanium compounds are preferably used because they are more often liquid and in any case more often and better soluble than those where this metal is at a valence of less than 4.
• the organic oxygenated compounds (T) of the titanium which can be used as reactants (2) can also be compounds comprising metal-oxygen bonds and condensed compounds comprising sequences of metal-oxygen-metal bonds, provided that they also comprise at least one sequence of metal-oxygen-organic radical bonds by molecule.
• the organic oxygenated compounds (T) can be represented by the general formula [TiO x (OR) 4-2x ] n where R represents an organic radical as defined above, where x is a number such that 0 ⁇ x ⁇ 1, 5 and where n is. an integer.
• R represents an organic radical as defined above, where x is a number such that 0 ⁇ x ⁇ 1, 5 and where n is. an integer.
• x is such that 0 ⁇ x ⁇ 1 and n such that 1 ⁇ n ⁇ 6.
• organic oxygenated compounds (T) comprising several different organic radicals also falls within the scope of the present invention.
• alpha-olefin polymers of wide molecular weight distribution it may be advantageous, for the manufacture of alpha-olefin polymers of wide molecular weight distribution, to additionally use at least one additional transition metal compound (reagent (4)) to prepare the solid catalytic complexes of l 'invention.
• This additional compound is then a compound (Z) chosen from organic oxygenated compounds and halogenated zirconium compounds.
• the solid catalytic complexes which can be used according to the present invention are finally prepared from reactants (3) which must be organoaluminum chlorides of general formula AlR n Cl 3-n in which R and n are as defined above.
• reagents (3) are preferably organoaluminum chlorides corresponding to the general formula above in which R is an alkyl radical, linear or branched, comprising from 4 to 18 carbon atoms and in which n is from 1 to 1.5 .
• the side chain is preferably single and short, and is in particular a methyl group.
• the branched radical is a single “iso” radical, that is to say a radical in which the substituent group is in position ⁇ with respect to the terminal carbon of the radical.
• organoaluminum chlorides correspond to the above formula., In which R is an alkyl radical, linear or branched, comprising from 4 to 18 carbon atoms, and in which n is 1.
• Organic chlorides corresponding to this definition - tion are for example the dichlorides of n-butyl- and isobutylaluminium, n-octyl- and isooctylaluminium, n-hexadécylaluminium, n-octadécylaluminium.
• a particularly preferred and easily accessible organoaluminum chloride is isobutylaluminum dichloride Al (iC 4 H 9 ) Cl 2 .
• reagent (3) is an essential characteristic of the invention. It is indeed the nature of this reagent which, surprisingly, is at the basis of the appreciable improvement in the morphology of polyolefins obtained according to the method of the invention.
• organoaluminum chlorides are not excluded from the scope of the invention, provided that the alkyl radicals contained in each of them contain at least 4 carbon atoms.
• organoaluminum chlorides can be prepared, optionally "in situ” and preferably prior to their use, in particular by mixing the corresponding trialkylaluminums with aluminum chlorides containing more chlorine than the chloride which it is desired to obtain.
• scope of the invention is not limited to the use of organoaluminum chlorides consisting exclusively of compounds corresponding to the general formula mentioned above but that it extends to technical products containing, in addition to a proportion substantial of these compounds, by-products such as the reagents used for their preparation. However, it is preferred that these products contain at least 80% by weight of organoaluminum chlorides corresponding to the general formula.
• the solid catalytic complexes of the invention can be prepared from the reactants (1), (2), (3) and optionally (4) above according to all the methods inducing a chemical reaction between them.
• a diluent in particular when the reagents are not themselves liquid under the operating conditions or when there are not enough liquid reagents.
• a diluent is generally chosen from those which are capable of dissolving at least one of the reactants and in particular from alkanes, cycloalkanes and aromatic hydrocarbons comprising from 4 to 20 carbon atoms such as for example the isobutane, hexane, heptane, cyclohexane, benzene, toluene, etc.
• polar solvents such as ethers and alcohols comprising from to 12 carbon atoms (ethanol and diethyl ether, for example), tetrahydrofuran, pyridine, methylene chloride, etc.
• a diluent dissolving at least one of the reagents it is preferred that the total concentration of the dissolved reagent (s) is greater than 5% by weight and preferably 20% by weight relative to the diluent.
• the reaction medium is preferably in the form of a relatively viscous liquid in which may be present. solid matter in dispersed state.
• the order of addition of the reagents is arbitrary.
• the reagents (3) can, in particular, be introduced into the reaction medium at any time during the preparation of the solid catalytic complex.
• reagent (3) takes place at the end of the preparation of the catalytic complexes, that is to say as soon as possible while the reagents (1) and (2) are brought together.
• the best results are obtained when the reagent (3) is used after the reagents (1) and (2) have been brought together in their entirety.
• the methods for preparing the solid catalytic complexes according to the invention also extend to the use, in place of the reactants (1) and (2) preformed, of magnesium, of a hydroxylated organic compound such as an alcohol and reagent (2).
• the pressure under which the preparation of the catalytic complexes is carried out, the rate of addition of the reactants and the duration of their contact are not critical factors. For reasons of convenience, one generally works under atmospheric pressure; the speed is generally chosen so as not to cause a sudden heating of the reaction medium due to a possible self-acceleration of the reaction; the duration can generally vary between 5 minutes and 12 hours.
• the reaction can be carried out continuously or batchwise.
• the temperature at which the reactant (1) and the reactant (2) are brought into contact is not critical. For reasons of convenience, it is generally chosen between 200 and -50 ° C., preferably between 150 ° C. and ambient temperature (25 ° C.).
• the temperature at which this reaction is carried out has an influence on the morphology of the polyolefin powder finally obtained.
• the temperature at which this reagent (3) is added to the product resulting from the prior mixing of the reagents (1) and (2) is suitably chosen.
• This temperature which is generally above 0 ° C and below the boiling temperature under ordinary pressure of organoaluminum chloride, is preferably between 30 and 65 ° C. The best results are obtained between around 45 and 60 ° C.
• the preparation of the catalytic complexes in accordance with the invention can advantageously be completed by a treatment of the ripening carried out at a temperature generally equivalent to or higher than that at which the reaction with the reagent (3) takes place for a non-critical period ranging from 5 minutes. at 12 o'clock in general, preferably for at least 1 hour.
• the quantity of compound (M), of compound (T) and of organoaluminum chloride (A) to be used preferably are specified below.
• the quantity of the compound (s) (T) to be used is defined relative to the total quantity of the compound (s) (M) used. It can vary widely. In general, it is between 0.01 and 10 at.-g (gram atom) of metal present in the compound (T) per at.-g of magnesium present in the compound (M). It has been observed that the performance of the catalytic complexes of the invention is optimal when a ratio of between 0.025 and 5 at.-g of titanium per at-g of magnesium is used. The best compromise between productivity (i.e.
• the amount of organoaluminum chloride to be used is also defined relative to the total amount of the compound (s) used. It can also vary widely. In general, it is between 1 and 100 moles of organoaluminum chloride per mole of compound (M). Preferably, this amount is between 1 and 20 moles per mole. The best compromise (as defined above) is obtained when this ratio is between 2 and 10 moles per mole.
• the catalytic complexes according to the invention are solid. They are insoluble in alkanes and cycloalkanes which can be used as diluents. They can be used in polymerization as they are obtained, without being separated from the reaction reaction medium. They can however be separated from this reaction medium, in particular when they are prepared in the presence of a polar solvent, by any known means.
• the reaction medium is liquid, it is possible to use, for example, filtration, decantation or centrifugation.
• the catalytic complexes can be washed so as to remove the excess reactants with which they could still be impregnated.
• Any inert diluent can be used for this washing, for example those which can be used as constituents of the reaction medium, such as alkanes and cycloalkanes.
• the eatalytic complexes can be dried, for example, by sweeping with a stream of dry nitrogen or under vacuum.
• the catalytic systems according to the invention also comprise an organometallic compound which serves as an activator.
• organometallic compounds of the metals of groups Ia, IIa, IIb, IIIb and IVb of the Periodic table such as organometallic compounds of lithium, magnesium, zinc, aluminum or tin. The best results are obtained with organoaluminum compounds.
• alkylated compounds whose alkyl chains contain from 1 to 20 carbon atoms and are straight or branched, such as for example lithium, diethylmagnesium, diethylzinc., Tetraethyltin, tetrabutyltin and trialkylalumi- niums.
• alkyl metal hydrides in which the alkyl radicals also comprise from 1 to 20 carbon atoms such as diisobutyl aluminum hydride and trimethyl tin hydride.
• metal alkyl halides in which the alkyl radicals also contain from 1 to 20 carbon atoms such as ethyl aluminum sesquichloride, diethyl aluminum chloride and diisobutyl aluminum chloride.
• organoaluminum compounds obtained by reacting trialkylaluminiums or dialkylaluminium hydrides whose radicals contain from 1 to 20 carbon atoms with diolefins comprising from 4 to 20 carbon atoms, and more particularly the compounds called isoprenylaluminiums.
• trialkylaluminiums whose alkyl chains are straight and contain from 1 to 18 carbon atoms. It is in fact found, quite surprisingly, that when these compounds serve as activators for the catalytic complexes prepared in accordance with the invention, that is to say by involving a reagent (3) which is an organoaluminum chloride as defined above, the molecular weight distributions of the polyolefins obtained are wider, all other conditions equal, than those of the polyolefins obtained in the presence of catalytic complexes prepared by using the usual reagents (3) (ethylaluminum dichloride).
• the process of the invention applies to the polymerization of terminal unsaturation olefins whose molecule contains from 2 to 20 atoms, and preferably from 2 to 6 carbon atoms, such as ethylene, propylene, butene- 1, 4-methylpentene-1 and hexene-1. It also applies to the copolymerization of these olefins together as well as with diolefins comprising preferably from 4 to 20 carbon atoms.
• diolefins can be non-conjugated aliphatic diolefins such as 1,4-hexadiene, monocyclic diolefins such as 4-vinylcyclohexene, 1,3-divinylcyclohexane, cycopentadiene or cyclo-octadiene-1,5, alicyclic diolefins having an endocyclic bridge such as dicyclopentadiene or norbornadiene and conjugated aliphatic diolefins such as butadiene and isoprene.
• non-conjugated aliphatic diolefins such as 1,4-hexadiene, monocyclic diolefins such as 4-vinylcyclohexene, 1,3-divinylcyclohexane, cycopentadiene or cyclo-octadiene-1,5, alicyclic diolefins having an endocyclic
• the process of the invention is particularly applicable to the manufacture of homopolymers of ethylene and of copolymers containing at least 90 molar Z and preferably 95 molar ethylene.
• the polymerization can be carried out according to any known process: in solution or in suspension in a hydrocarbon solvent or diluent or also in the gas phase.
• solvents or diluents similar to those used for the preparation of the catalytic complex are used: these are preferably alkanes or cycloalkanes such as isobutane, pentane, hexane, l 'heptane, cyclohexane, methylcyclohexane or mixtures thereof.
• alkanes or cycloalkanes such as isobutane, pentane, hexane, l 'heptane, cyclohexane, methylcyclohexane or mixtures thereof.
• the polymerization processes in suspension in a liquid hydrocarbon diluent under the polymerization conditions are preferred, which, after separation of the unreacted monomer and the diluent, provide, in the presence of catalytic systems of the invention, polymer particles which have the morphological characteristics of the powders used in the transformation processes mentioned above. ;
• the polymerization pressure is generally between atmospheric pressure 2 and 100 kg / cm, preferably 50 kg / cm.
• the temperature is generally chosen between 20 and 200 ° C. It is preferably between 60 and 120 ° C so as to directly obtain the polymer in solid form. No degradation in the morphology of the polyolefin particles obtained in the presence of the catalytic systems of the invention is observed when the polymerization temperature is lowered in this preferred zone. On the contrary, when solid catalytic complexes are prepared from the usual reagents (3) of the prior art, it is found that the lowering of the polymerization temperature exerts a detrimental effect on the morphology of the polyolefin obtained (the particles are thinner and less harsh).
• the polymerization can be carried out continuously or batchwise.
• the organometallic compound and the catalytic complex can be added separately to the polymerization medium: They can also be brought into contact, at a temperature between -40 and 80 ° C, for a period of up to 2 hours, before they are removed. introduce into the polymerization reactor. They can also be brought into contact in several stages or else add a part of the organometallic compound before the reactor or else add several different organometallic compounds.
• the total amount of organometallic compound used can vary to a large extent. It is generally between 0.02 and 50 mmol per dm 3 of solvent, diluent or reactor volume and preferably between 0.5 and 2.5 mmol per dm 3 .
• the ratio of the amounts of organometallic compound and catalytic complex is also not critical. It is generally chosen so that the organometallic compound / titanium ratio expressed in mole / at.-g is greater than 1 and preferably greater than 10.
• the average molecular weight, and therefore the melt index of the polymers produced according to the process of the invention can be adjusted by the addition to the polymerization medium of one or more molecular weight modifiers such as hydrogen, zinc or cadmium diethyl, alcohols or carbon dioxide.
• molecular weight modifiers such as hydrogen, zinc or cadmium diethyl, alcohols or carbon dioxide.
• the specific gravity of the homopolymers manufactured according to the process of the invention can also be adjusted by the addition to the polymerization medium of a 1 ⁇ m alkoxide metal from groups IVa and Va of the Periodic Table.
• the polymerization medium of a 1 ⁇ m alkoxide metal from groups IVa and Va of the Periodic Table can be adjusted by the addition to the polymerization medium of a 1 ⁇ m alkoxide metal from groups IVa and Va of the Periodic Table.
• alkoxides suitable for this adjustment those of titanium and vanadium whose radicals contain from 1 to 20 carbon atoms each are particularly effective. These include Ti (OCH 3 ) 4 , Ti (OC 2 H 5 ) 4 , Ti [OCH 2 CH (CH 3 ) 2 ] 4 , Ti (OC 8 H 17 ) 4 and Ti (OC 16 H 33 ) 4 ,
• the process of the invention makes it possible to manufacture polyolefins with very high productivities.
• productivity expressed in grams of polyethylene per gram of catalytic complex used regularly exceeds 10,000 and in some cases 20,000.
• the activity related to the amount of transition metals present in the catalytic complex is also very high.
• homopolymerization of ethylene also expressed in grams of polyethylene per at.-g of titanium used, it regularly exceeds 200,000. In the most favorable cases, it is greater than 500,000.
• the content of catalytic residues in the polymers produced according to the process of the invention is. extremely low. More particularly, the content of residual transition metal is excessively low.
• the content of the annoying residues in polymers is so low that it is possible to save on the purification treatment (for example an alcohol treatment), which is compulsory when the content catalytic residue is high and is an expensive operation in terms of raw materials and energy and requiring considerable fixed assets.
• the purification treatment for example an alcohol treatment
• the polyolefin powders produced in accordance with the invention are therefore characterized by a remarkable morphology and can be used in this form. This is particularly the case for the powders of ethylene polymers.
• the polyolefins obtained according to the invention can however be granular and be used in the form of granules according to conventional molding techniques: by injection, by extrusion, by extrusion- blowing, calendering, etc.
• a stock solution (S) is prepared by heating together, at 150 ° C, with stirring and for 2 hours, 9 moles of the reagent (2) and 4.5 moles of the reagent (1).
• the Ti / Mg atomic ratio is therefore approximately 2 at.-g / at.-g. 500 ml of the stock solution (S), in which it. there has been almost complete dissolution of the reagent (1) and which has been cooled beforehand, 1000 ml of hexane are added, so as to obtain a solution at approximately 500 g / bed.
• organoaluminum chlorides used according to Examples 2, 3, 4 were prepared, in a known manner, by reaction of the corresponding trialkylaluminum with aluminum trichloride.
• organoaluminum chlorides are used in the form of solutions in hexane at 400 g / bed. They are gradually added to fractions of stock solutions (S), diluted as indicated above, at a temperature of about 50 ° C and with stirring, for about 90 minutes. At the end of this addition, the reaction mixture is subjected to curing for 1 hour at 60 ° C.
• the amount of organoaluminum chloride used in each of the examples is such that the molar ratio of organoaluminum chloride / magnesium ethylate is approximately 10.
• the catalytic complexes thus formed are used as such, without being separated from their reaction medium, in polymerization tests the general conditions of which are defined below.
• the polymerization is continued for 1 hour with stirring while keeping the total pressure constant by continuous addition of ethylene. After 1 h, the autoclave is degassed and the polyethylene thus produced is collected.
• Table I lists the conditions specific to each test, the results obtained and the morphological characteristics of the polyethylenes produced.
• Table I shows that the use of organoaluminum chlorides meeting the definition of the invention as reagents (3) (examples 1 to 4) leads, with improved catalytic activities, to polyethylenes which contain a proportion of large particles clearly higher than that present in the polyethylenes obtained with the usual reagent (3) of the prior art (example 5 R).
• Example 7 R is given for comparison.
• Catalytic complexes are prepared in accordance with the preceding examples except that the reactants (2) and (1) are mixed so that the atomic ratio Ti / Mg is approximately 1.2 at.-g / at.-g, that the amount of organoaluminum chloride used is such that the molar ratio of organoaluminum chloride / magnesium ethylate is approximately 3.5 and that the organoaluminum chloride is added at a temperature of approximately 30 ° C.
• Example 6 the catalytic complex is prepared by using isobutylaluminum dichloride as the organoaluminum chloride.
• Example 7 - R the catalytic complex is prepared by making use of ethylaluminum dichloride as organoaluminum chloride.
• the catalytic complexes obtained are used in the form of a suspension in the medium which served to prepare them for carrying out ethylene polymerization tests under general conditions absolutely identical to those described in the previous examples.
• organoaluminum chloride (reagents (3)) meeting the definition of the invention remain acquired despite significant changes in the molar ratios between reagents.
• Catalytic complexes are prepared in accordance with Examples 1 to 5 R using isobutylaluminum dichloride as the organoaluminum chloride.
• Catalytic complexes are prepared in accordance with Examples 1 to 5 R using isobutylaluminum dichloride used at 50 ° C, as the organoaluminum compound in Examples 13 to 15, and ethylaluminum dichloride, used at 30 ° C, in examples 16 R to 18 R.

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• 1978
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