CA1212500A - Copolymerization of ethylene and hexene-1 in fluidised bed - Google Patents
Copolymerization of ethylene and hexene-1 in fluidised bedInfo
- Publication number
- CA1212500A CA1212500A CA000436128A CA436128A CA1212500A CA 1212500 A CA1212500 A CA 1212500A CA 000436128 A CA000436128 A CA 000436128A CA 436128 A CA436128 A CA 436128A CA 1212500 A CA1212500 A CA 1212500A
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- CA
- Canada
- Prior art keywords
- organo
- compound
- support
- ethylene
- accordance
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
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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
- C08F210/00—Copolymers of unsaturated aliphatic hydrocarbons having only one carbon-to-carbon double bond
- C08F210/16—Copolymers of ethene with alpha-alkenes, e.g. EP rubbers
-
- 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
- Y10S526/901—Monomer polymerized in vapor state in presence of transition metal containing catalyst
-
- 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
- Y10S526/903—Monomer polymerized in presence of transition metal containing catalyst and hydrocarbon additive affecting polymer properties of catalyst activity
-
- 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
- Y10S526/904—Monomer polymerized in presence of transition metal containing catalyst at least part of which is supported on a polymer, e.g. prepolymerized catalysts
Abstract
ABSTRACT
Copolymerisation of Ethylene and Hexene-1 in a Fluidised Bed Process for the preparation of copolymers of ethylene and hexene-1 with a density comprised between 0.910 and 0.940, involving a copolymerisation of ethylene and hexene-1 in the gas phase by means on d fluidised bed, in the presence of a catalyst system comprising on the one hand a co-catalyst consisting of at least one organo-metallic compound of a metal of Groups II and III of the Periodic Table of Elements and on the other hand a supported catalyst comprising a special support based essentially on magnesium chloride and optionally aluminium chloride, on which support there has been precipitated a derivative of a transition metal of Groups IV, V and VI of the Periodic Table of Elements.
Copolymerisation of Ethylene and Hexene-1 in a Fluidised Bed Process for the preparation of copolymers of ethylene and hexene-1 with a density comprised between 0.910 and 0.940, involving a copolymerisation of ethylene and hexene-1 in the gas phase by means on d fluidised bed, in the presence of a catalyst system comprising on the one hand a co-catalyst consisting of at least one organo-metallic compound of a metal of Groups II and III of the Periodic Table of Elements and on the other hand a supported catalyst comprising a special support based essentially on magnesium chloride and optionally aluminium chloride, on which support there has been precipitated a derivative of a transition metal of Groups IV, V and VI of the Periodic Table of Elements.
Description
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The present inventlon relates to a process for the production of copolymers of ethylene and hexene-l with a density comprised between 0.910 and 0.94Q, obtained by copolymerisation in the gas phase by means of a fluidised bed.
It i~ alrea~y known that one can produce in solution in a iiquid hydrocarbon medium copolymers of ethylene and an alpha-olefin comprising more than 5 carbon atoms. Processes of this type require the use of solvents and involve delicate operations to recover the copolymer from the solution. Moreover, a not inconsiderable part of the copolymer remalns dissolved in the solvent, which renders the operations of recovery and purification of the said solvent difficult.
It is also known that one can produce in the gas phase copolymers of ethylene and higher alpha-olefins comprising more than 5 carbon atoms, the6e copolymers having a density comprised between 0.900 and 0.940, the copolymerisation being effected in the presence of a catalyst system comprising a solid catalyst obtained by pulverising a magnesium compound, such as magnesium chloride, and a compound of a transition metal. In view of its broad particle size distribu~ion, a catalyst of this type cannot be utilised for polymerisatlon carried out in reactors with a fluidised bed in which the speed of fluidisation is high, for example comprised between 5 and lO times the minimum speed of fluidisation, without causing a considerable carry-over of particles from the fluidised bed.
A process has also been proposed for copolymerising in the gas 25U~
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phase ethylene and higher alpha-ole~ins compris:ing up to 6 carbon atoms, by means of a fluidised bed and in the pres~nce of a catalyst system comprising as catalyst a solid compound of magnesium, titanium and halogen, obtained by reacting tetravalent titanium compounds with an organo-magnesium compoun~ (or magnesium metal) and - an alkyl halide. According to this process the copolymer during its formation in the fluidised bed occurs (especially when the higher alpha olefin employed comprises more than 4 carbon atoms), in the form of a powder composed of sticky particles, favouring the formation of agglomerates which are prejudicial to the proper operation of the fluidised bed.
A process has now been found which makes it possible to avoid these drawbacks and obtain without difficulty by copolymerisation in the gas phase by means of a fluidised bed copolymers of ethylene and hexene-1 having a density comprised between 0.910 and 0.940.
The object of the present invention is therefore a process for obtaining such copolymers by the copolymerisation of ethylene and a hexene-1 in the gas phase by means of a fluidised bed in contact with a catalyst system consisting of:
(i) a co-catalyst consisting of a organo-metallic compound of a metal of Groups II and III of the Periodic Table of Elements, (ii~ a supported catalyst, the support being basically a magnesium chloride having specific properties and the catalyst comprising a derivative :of a me~al belonging to Groups IV, V and VI of the ~5 Periodic Table of Elements, especially a titanium compound known for its catalytic properties in the polymerisation of ethylene and alpha-olefins.
According to the invention, the catalyst support consists of particles based essentially on magnesium chloride, which have the following characteristics:
- the particles have a spheroidal form defined by the fact that if D and d are the large and small axes of these particles, D/d is not greater than 1.3;
- the particles have a mean diameter by mass adjustable at will and comprised between approximately 10 and 100 microns;
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- the particle size distribution of these particles is such that the ratio Dm:Dn of the mean diameter by mass, Dm, to the mean - diameter by number, Dn, is not greater than 3, for example comprised between 1.1 and 2.5; more especially the particle size distribution S of these particles is very narrow and is such that the ratio Dm:Dn - is comprised between 1 and 1.5; in addition, the practically total absence of particles of a diameter greater than 2 x Dm or less than 0~2 x Dm may be noted; the particle size distribution may also be such that more ~han 90 per cent by weight of the particles of one and the same batch are comprised in the bracket Dm~10%;
- the particles may have a slightly dented surface such as that of a raspberry; but preferably have a very smooth surface;
- the specific surface area of the particles is comprised between about 20 and 60 m2/g (BET);
- the dens~ty of the particles is comprised between about 1.6 and
. .
The present inventlon relates to a process for the production of copolymers of ethylene and hexene-l with a density comprised between 0.910 and 0.94Q, obtained by copolymerisation in the gas phase by means of a fluidised bed.
It i~ alrea~y known that one can produce in solution in a iiquid hydrocarbon medium copolymers of ethylene and an alpha-olefin comprising more than 5 carbon atoms. Processes of this type require the use of solvents and involve delicate operations to recover the copolymer from the solution. Moreover, a not inconsiderable part of the copolymer remalns dissolved in the solvent, which renders the operations of recovery and purification of the said solvent difficult.
It is also known that one can produce in the gas phase copolymers of ethylene and higher alpha-olefins comprising more than 5 carbon atoms, the6e copolymers having a density comprised between 0.900 and 0.940, the copolymerisation being effected in the presence of a catalyst system comprising a solid catalyst obtained by pulverising a magnesium compound, such as magnesium chloride, and a compound of a transition metal. In view of its broad particle size distribu~ion, a catalyst of this type cannot be utilised for polymerisatlon carried out in reactors with a fluidised bed in which the speed of fluidisation is high, for example comprised between 5 and lO times the minimum speed of fluidisation, without causing a considerable carry-over of particles from the fluidised bed.
A process has also been proposed for copolymerising in the gas 25U~
~ . ~
phase ethylene and higher alpha-ole~ins compris:ing up to 6 carbon atoms, by means of a fluidised bed and in the pres~nce of a catalyst system comprising as catalyst a solid compound of magnesium, titanium and halogen, obtained by reacting tetravalent titanium compounds with an organo-magnesium compoun~ (or magnesium metal) and - an alkyl halide. According to this process the copolymer during its formation in the fluidised bed occurs (especially when the higher alpha olefin employed comprises more than 4 carbon atoms), in the form of a powder composed of sticky particles, favouring the formation of agglomerates which are prejudicial to the proper operation of the fluidised bed.
A process has now been found which makes it possible to avoid these drawbacks and obtain without difficulty by copolymerisation in the gas phase by means of a fluidised bed copolymers of ethylene and hexene-1 having a density comprised between 0.910 and 0.940.
The object of the present invention is therefore a process for obtaining such copolymers by the copolymerisation of ethylene and a hexene-1 in the gas phase by means of a fluidised bed in contact with a catalyst system consisting of:
(i) a co-catalyst consisting of a organo-metallic compound of a metal of Groups II and III of the Periodic Table of Elements, (ii~ a supported catalyst, the support being basically a magnesium chloride having specific properties and the catalyst comprising a derivative :of a me~al belonging to Groups IV, V and VI of the ~5 Periodic Table of Elements, especially a titanium compound known for its catalytic properties in the polymerisation of ethylene and alpha-olefins.
According to the invention, the catalyst support consists of particles based essentially on magnesium chloride, which have the following characteristics:
- the particles have a spheroidal form defined by the fact that if D and d are the large and small axes of these particles, D/d is not greater than 1.3;
- the particles have a mean diameter by mass adjustable at will and comprised between approximately 10 and 100 microns;
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- the particle size distribution of these particles is such that the ratio Dm:Dn of the mean diameter by mass, Dm, to the mean - diameter by number, Dn, is not greater than 3, for example comprised between 1.1 and 2.5; more especially the particle size distribution S of these particles is very narrow and is such that the ratio Dm:Dn - is comprised between 1 and 1.5; in addition, the practically total absence of particles of a diameter greater than 2 x Dm or less than 0~2 x Dm may be noted; the particle size distribution may also be such that more ~han 90 per cent by weight of the particles of one and the same batch are comprised in the bracket Dm~10%;
- the particles may have a slightly dented surface such as that of a raspberry; but preferably have a very smooth surface;
- the specific surface area of the particles is comprised between about 20 and 60 m2/g (BET);
- the dens~ty of the particles is comprised between about 1.6 and
2.2;
- the particles consist essentially of magnesium chloride and optionally aluminium chloride; the particles preferably contain a small proportion of products with an Mg-C bond and consequently the atcmlc ratio Cl/(Mg + 3/2 Al) is preferably slightly less than 2;
- the particles preferably contain a small proportion of an electron donor compound.
The supports thus defined may in particular be prepared by reacting an organo-magnesium compound with a chlorinated organic compound in the presence of an electron donor compound. As organo-magnesium compound one may choose either a product of the formula RlMgR2, or an addition complex of the formula RlMgR
xAl(R3)3, in which formulae Rlr R2 and R3 are identical or different alkyl radicals having from 2 to 12 carbon atoms and x is comprised between 0.001 and 10, preferably comprised between 0.01 and 2. As chlorinated organic compound one selects an alkyl chloride of the formula R4Cl in which R4 is a secondary or preferably tertiary alkyl radiçal having from 3 to 12 carbon atoms.
The electron donor compound utilised is an organic compound comprising at least one atom of oxygen, sulphur, nitrogen and/or ,, .
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phosphorus. It may be chosen from among a wide variety of products such as the amines, amides, phosphines, sulphoxides, sulphones and ethers. Among the electron donor compounds one may select in particular an aliphatic ether oxide of the formula RsOR6, in which Rs and R6 are identical or different alkyl radicals having - from 1 to 12 carbon atoms.
Moreover9 the various reactants utilised for the preparation of the support such as defined above mus~ be employed under the following conditions:
- the molar ratio R4Cl/R1MgR2 is comprised between 1.5 and 2.5 and preferably is comprised between 1~85 and 1.95;
the molar ratio R4Cl/R1MgR2,xAl(R3)3 is comprised between 1~5 (1 ~ 3/2.x) and 2.5 (1 + 3/2.x), and preferably between 1.85 (1 ~ 3/2.x) and 1.95 (1 + 3/2.x);
- ~he molar ratio between the electron donor compound and the organo-magnesium compound (RlMgR2 or RlMgR2.xAl(R3)3 is comprised between 0.01 and 2, and preferably ls comprised between 0.01 and 1;
- the reaction between the organo~magnesium compound and the chlorinated organic compound takes place with agitation in a liquid hydrocarbon at a temperature comprised between 5C and 80C and especially between 35C and 80~C.
The preparation of the catalysts from the supports thus defined i6 carried out by precipitation on to the said supports of a derivative of a transition metal of Groups IV, V and VI of the Periodic Table of Elements known for its catalytic properties in the polymerisation and the co~polymerisa~ion of ethylene and aipha-olefins, especially of a compound of titanium whose valency is less than 4. This precipitation may be performed according to known processes, but is advantageously effected according to the following process:
- The reaction of reducing a titanium compound at its maximum valency, of the formula Ti(OR7)4_nXn, in which R7 is an alkyl group containing 2 to 6 carbon atoms, X is a chlorine or bromlne atom and n is an integer or fraction from 1 to 4 inclusive, ,, .
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is carried out by means of a reducing agent chosen from among the organo-magnesium compounds of the formula R8 MgRg, in which R8 and Rg are identical or different alkyl groups containing 2 to 12 carbon atoms, organo-zinc compounds o~ the formula Zn(Rl0)(2-y)Xy~ in which Rlo is an alkyl group having 2 to 12 carbon atoms, X is chlorine or bromine and y is zero, one, or a fraction between 0 and l, and organo-aluminium compounds of the formula Al~R11)(3-X)XX, in which Rll is an alkyl group having 2 to 12 carbon atoms, X is chlorine or bromine and x is zero or an in~eger or fraction not greater than 2;
- the said reduction reaction is performed in the presence or absence o~ an electron donor compound chosen from among a wide variety of organic compounds comprising at least one atom o oxygen, sulphur, nitrogen and/or phosphorus, such as for example amines, amide~, phosphines, sulphoxides, sulphones or ethers; as electron donor compound, one may choose in particular an aliphatic ether oxide of the formula ~120R13, in which R12 and R13 are identical or different alkyl groups having 1 to 12 carbon atoms;
- the relative molar quantities of the various compounds (support, titanium compound, organo-magnesium and/or organo-zinc and/or organo-aluminium compound, electron donor or ether oxide) are, in molar ratios, such that:
O Support:compound of titanium comprised between 1 and 50, and preferably comprised between 2.5 and 10;
. Organo-magnesium and/or organo-zinc and/or organo-aluMinium compound:titanium compound comprised between 0.1 and 3, pre~erably comprised between 0.5 and 1.5;
. Electron donor compound or ether oxide:titanium compound comprised between 0 and S, and preferably comprised between 0.1 and 1.5~
The precipitation is effected at a temperature comprised between -30C and 100C with agitation, in a liquid hydrocarbon medlum.
The use of the reagents in this precipitation may be carried out in various ways. One may, for example, introduce the reducing ~21;~5~
agent gradually (organo-magnesium or organo-zinc or organo-aluminium compound) into a liquid hydrocarbon medium containing the magnesium chloride support and the titanium compound. It is also possible to introduce gradually and simultaneously the reducing agent and the titanium compound into the liquid hydrocarbon medium containing the magnesiu~ chloride support. However, it is generally preferable to introduce the titanium compound gradually into the liquid hydrocarbon medium containing the magnesium chloride support and the reducing agent.
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The catalysts obtained according to the present invention occur in the form of a powder, generally of a brownish~red colour, consisting of particles whose physical properties such as the spheroidal shape, surface appearance, mean diameter by mass and particle size distribution defined by the ratio Dm/Dn, are more or less identical to those of the particles of magnesium chloride support form which they originated.
After the evaporation of the liquid hydrocarbon medium in which ~hey were prepared, the catalysts according to the present invention are used for the copolymerisation of ethylene and hexene-1, using known techniques of polymerisation in the gas phase by means of a fluidised bed~
The copolymerisation is performed by using as co-catalyst an organo-metallic compound of a metal of Groups II and III of the Periodic Table, preferably an organo-aluminium or organo-aluminium halide compound. The components of the catalyst system must be used in proportions such that the atomic ratio of the quantity of metal of Groups II and III of the co-catalyst to the quantity of transition metal of Groups IV, V and VI of the catalyst is comprised between O.S and 200, preferably comprised between 1 and 50.
The catalytic systems used may be employed as such or after undergoing a pre-polymerisation operation. This pre-polymerisation operation leads to the production of particles whose dimensions and shapes are more or less homothetic to those of the initial catalyst, le the shapes of the prepolymer particles are, in effect, "magnified" derivatives of the original particles. The - ~23LZS(~
pre-polymerisation consists in bringing the catalyst and co-catalyst in contact with ethylene optionally in admixture with an alpha-olefin such as a hexene-l; the pre-polymerisation may advantageously be performed in two stages as described below. The S catalytic products thus obtained are particularly suited to the co-polymerisa~ion of ethylene and a hexene-l in a fluidised bed:
these products possess the dimensions, resistance to abrasion and reactivity which can be adapted to this mode of polymerisation, - making it possible to obtain a non-sticky powder, which in particular is free from co-polymers with a low melting point having both a low molecular weight and a relatively high content of hexene-l.
The commencement of the pre-polymerisation reaction (or the first stage of this reaction when one operates in two distinct lS stages) i9 suitably performed in suspension in an inert liqu~d medium.
This first pre-polymerisation stage is continued until each particle of catalyst comprises 0.1 to lOg of polyethylene or ethylene copolymer per milligramme atom of transition metal present in the catalyst. The prepolymerisation may then be continued either in suspension in a liquid hydrocarbon medium or in the dry state;
generally speaking it may be continued - whilst retaining a suitable activity in the catalyst - until 10 to 500 g of polyethylene or ethylene copolymer are obtained per milligramme atom of transition metal present in the catalyst.
The prepolymer obtained according to this process occurs in the form of a powder consisting of particles having a mean diameter by mass generally comprised between 80 and 300 microns, preferably comprised between 100 and 240 microns, and a particle size distribution such that the ratio Dm/Dn is less than or equal to 3, preferably comprised between 1.1 and 2.5; the prepolymer powder contains practically no particles with a diameter greater than 2 x Dm or less than 0.2 x Dm.
The copolymerisation in the gas phase by means of a fluidised bed may be performed according to conventional techniques of 5~
fluidlsed bed polymerisation and copolymerisation. However, the gaseous mixture providing the fluidisation comprises, in addition to the monomeric ethylene and hexene-l to be polymerised, an inert gas such as nitrogen, methane or ethane and optionally hydrogen to regulate the molecular weights of the copolymers obtained. The presence of an inert gas in this gaseous mixture appreciably improves the elimina~ion of the heat of reaction and favourably modifies the kinetics of copolymerisation. The speed of - fluidisation in the fluidised bed reactor is preferably high enough to facilitate homogenisation of the fluidised bed and to eliminate - effectively the heat given off by the copolymerisation~ without having recourse to any other means of homogenisation, especially mechanical. The speed of fluidisation is preferably equal to 5 to 10 times the minimum speed of fluidisation, that is ~o say generally lS compr~sed between about 40 and 80 cm/sec. In traversing the ~luidised bed only a part of the ethylene and hexene-1 polymerises in contact with the particles of the copolymers in course of growth. The gaseous mixture containing the fraction of ethylene and hexene-1 which has not reacted leaves the fluidised bed and passes through a cooling system intended eo eliminate the heat produced during the reaction, ~efore being recycled into the fluidised bed reactor by means of a compressor.
The copolymerisation is suitably performed at a temperature comprised between about 50C and 90C, preferably between 70C and Z5 90C, under a total pressure which may vary in the range generally comprised between 0.5 MPa and 4 MPa.
The partial pressure (pp) of the varlous constituents of the fluidised gas stream suitably comply with the ~ollowing ratios:
pp hexene-1 is in the range 0.05 MPa to 0.15 MPa:
pp hexene-1/pp ethylene is in the range 0.15 to 0.5:
pp hydrogen/pp ethylene is in the range 0~05 to 0.5:
pp iner~ gasttotal pressure is in the range 0.2 to 0.9.
The hexene-1 employed is preferably a hPxene-1 having a relatively low boiling point, for example 4-methyl-pentene-1.
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When operatlng according to the process as described above using in particular 4-methyl-pentene-1 as the hexene-1, one obtains copolymers containing approximately 4 to 15 per cent by weight of units derived from 4-methyl-pentene-1 and having densities comprised between 0.910 and 0.940.
These copolymers occur directly after the copolymerisation in the fluidised bed in the form of powders consisting of non-sticky particles, having a negligible proportion of copolymers with a low melting point having both a low molecular weight and a relatively high content of hexene-l.
These copolymer powders, which are easy to handle, have a comparatively high bulk density, comprised between 0.~0 and 0.45 g/cm3, preferably comprised between 0.35 and 0.45 g/cm3.
The copolymer particles making up these powders have a spheroidal shape, defined by the fact that if D and d are the large and small axis of these particles respectively, D/d is less than or equal to 1.3. These partlcles have mean diameter by mass, Dm, comprised between 300 and 1500 microns, preferably comprised between 500 and 1200 microns. The particle size distribution o these par~icles is such that the ratio Dm/Dn is less than or equal to 3.5, p~eferably comprised between 1.2 and 3. The width of particle size distribution of this powder wh-ich constitutes the fluidised bed depends not only on that of the prepoly~er used, but also on the mean residence time of the copolymer in the fluidised bed reactor, and also on the rate at which the catalytic system loses its activity during the copolymerisation reaction. In particular it is advsntageous in such a process to employ a catalyst system which loses its activity relatively rapidly during the copolymerisation reaction, in order to obtain a powder havlng the narrowest possible particle size distribution.
These copolymers of ethylene and 4-methyl-pen~ene-1 are also characterised by a very low degree of unsaturation, of less than 0,2 double bond per 1000 carbon atoms, which imparts to them an excellent stability.
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By scanning differential calorimetric analysis, after re-heating to 200C, cooling at a speed of 16C per minute, and heating at the rate of 16C per minute, these copolymers show a - single melting point at a tempera~ure comprised between 116 and 128C, the fusion pattern characteristically showing a single peak at this temperature, which corresponds to a single distribution of the crystallite dimensionsO
The structure of the copolymers is also characterised by a very - small amount of long-chain branches (g*), which is expressed by a vzlue g* = (~ greater than or equal to 0.90, (~) being - the intrinsic viscosity of a given copolymer and (~1) being the intrinsic viscosity of a linear polyethylene having the same weLght average molecular weight as the said copolymer.
These copoly~ers whose melt index under 2.16 kg and at 190C, lS according to Standard ASTM D 1238, may vary between 0.1 and 30 g per lO minutes, have some particularly interesting applications in the production of films with a high mechanical strength.
Method for determinin~ the mean diameters by mass (Dm) and by number(Dn)_of particles. (Support, catalyst, prepolymer, polymer) According to the invention, the mean diameters by mass (Dm) and by number (Dn) of the particles of support, catalyst, prepolymer or polymer are measured from microscope readings by means of the OP~O~AX image analyser (Micro-~easurements Ltd., Great Britain), The mèasuring principle consists in obtaining from the experimental study by optical microscopy of a population of particles a table of absolute frequencies which gives the number (ni) of particles belonging to each category (i) of diameters, each category (i) being characterised by an intermediate diameter ~di), comprised between the limits of the said category. According to the approved French standard NF X 11-630 of June 1981, Dm and Dn are provided by the following equations:
O mean diameter by mass: Dm = ~ ni (di)_ di ni (di)3 . mean diameter by number: Dn = ni.di ~ ni O
~2~25~
. .
The ratio Dm/Dn characterises the particle size distribution;
it is sometimes referred to as "width of particle size distributlon".
The measurement by the OPTOMAX image analyser is performed by means of an inverted microscope which makes it possible to examine suspensions of particles at a magnification hetween 16 and 200 X. A
television camera picks up the images given by the inverted mlcroscope and transmlts them to a compu*er which analyses the images line by line and dot by dot on each line, in order to determine the dimensions or diameters of the particles and then to classify them.
The following non-restrictive Examples illustrate the invention.
Example 1 (a) Production of the catalyst Preparation of the support Into a 5-litre stainless steel reactor, provided with a system o agitation rotating at 750 revolutions per minute and containing 800 ml of n-hexane, there are introduced at ambient temperature (20C) and under a blanket of nitrogen: 1725 ml of a solution of butyloctylmagnesium in heptane containing 1500 milligramme-atoms of magnesium and 61 ml (300 millimoles) of di-isoamyl ether (DIAE).
The reactor is then heated to 50C and over 3 hours 313 ml of tertiary-butyl chloride (or 2850 millimoles) are poured ln drop by drop. At the end of this addition, the suspension is maintained at S0C for 3 hours and the precipitate (A) obtained is then washed five times with n-hexane, The washed product (A) constitu~es the support, its chemical composition is as follows per gramme-atom of magnesium:
- 1.97 gramme-atom of chlorine;
- 0.03 gramme equivalent of Mg-C bond;
- 0.02 mole of di-isoamyl ether.
On examination under the microscope it was possible to see that ~he magnesium chlorine support occurs in the form of a powder consisting of spheroidal particles (the mean ratio between large and 5~0 small axes, D/d of the particles is equal to 1.2), having a narrow particle size distribution defined by the ratio Dm/Dn = 1.29 where Dm = 33 microns; in addition it is found that more than 90 per cent by weight of the particles have a mean diameter comprised between 30 and 36 microns. The density of the product is equal to 1.9 and its specific surface area to 38 m2/g; the surface of the particles is smooth~
Preparation_of the catalyst , - Into 3000 ml of suspension in n-hexane of the washed product (A) obtainéd above, containing 1450 millimoles of MgC12, - there are added with agitation 82 ml of di-isoamyl ether and 400 ml of a 1.2 molar solut$on in n-hexane (or 480 millimoles) of diethyl aluminium chloride. The reactor is heated to 50C and over 2 hours 650 ml of a 0.6 molar so}ution of di-n-propoxy titanium dichloride (390 milli~oles) in n-hexane are added drop by drop. At the end of thls addition, the temperature is raised to 80C and it is maintained at this figure for 2 hours. The solid product is then washed five times with n-hexane to produce the catalyst (B) ready for use. Analysis of the catalyst shows that it contains per gramme ato~ of total titanium:
- 0.06 gramme-atom of tetravalent titanium;
- 0.94 gramme-atom of trivalent titanium;
- the particles consist essentially of magnesium chloride and optionally aluminium chloride; the particles preferably contain a small proportion of products with an Mg-C bond and consequently the atcmlc ratio Cl/(Mg + 3/2 Al) is preferably slightly less than 2;
- the particles preferably contain a small proportion of an electron donor compound.
The supports thus defined may in particular be prepared by reacting an organo-magnesium compound with a chlorinated organic compound in the presence of an electron donor compound. As organo-magnesium compound one may choose either a product of the formula RlMgR2, or an addition complex of the formula RlMgR
xAl(R3)3, in which formulae Rlr R2 and R3 are identical or different alkyl radicals having from 2 to 12 carbon atoms and x is comprised between 0.001 and 10, preferably comprised between 0.01 and 2. As chlorinated organic compound one selects an alkyl chloride of the formula R4Cl in which R4 is a secondary or preferably tertiary alkyl radiçal having from 3 to 12 carbon atoms.
The electron donor compound utilised is an organic compound comprising at least one atom of oxygen, sulphur, nitrogen and/or ,, .
5~
. . .
phosphorus. It may be chosen from among a wide variety of products such as the amines, amides, phosphines, sulphoxides, sulphones and ethers. Among the electron donor compounds one may select in particular an aliphatic ether oxide of the formula RsOR6, in which Rs and R6 are identical or different alkyl radicals having - from 1 to 12 carbon atoms.
Moreover9 the various reactants utilised for the preparation of the support such as defined above mus~ be employed under the following conditions:
- the molar ratio R4Cl/R1MgR2 is comprised between 1.5 and 2.5 and preferably is comprised between 1~85 and 1.95;
the molar ratio R4Cl/R1MgR2,xAl(R3)3 is comprised between 1~5 (1 ~ 3/2.x) and 2.5 (1 + 3/2.x), and preferably between 1.85 (1 ~ 3/2.x) and 1.95 (1 + 3/2.x);
- ~he molar ratio between the electron donor compound and the organo-magnesium compound (RlMgR2 or RlMgR2.xAl(R3)3 is comprised between 0.01 and 2, and preferably ls comprised between 0.01 and 1;
- the reaction between the organo~magnesium compound and the chlorinated organic compound takes place with agitation in a liquid hydrocarbon at a temperature comprised between 5C and 80C and especially between 35C and 80~C.
The preparation of the catalysts from the supports thus defined i6 carried out by precipitation on to the said supports of a derivative of a transition metal of Groups IV, V and VI of the Periodic Table of Elements known for its catalytic properties in the polymerisation and the co~polymerisa~ion of ethylene and aipha-olefins, especially of a compound of titanium whose valency is less than 4. This precipitation may be performed according to known processes, but is advantageously effected according to the following process:
- The reaction of reducing a titanium compound at its maximum valency, of the formula Ti(OR7)4_nXn, in which R7 is an alkyl group containing 2 to 6 carbon atoms, X is a chlorine or bromlne atom and n is an integer or fraction from 1 to 4 inclusive, ,, .
5~
. .
'' `:`
is carried out by means of a reducing agent chosen from among the organo-magnesium compounds of the formula R8 MgRg, in which R8 and Rg are identical or different alkyl groups containing 2 to 12 carbon atoms, organo-zinc compounds o~ the formula Zn(Rl0)(2-y)Xy~ in which Rlo is an alkyl group having 2 to 12 carbon atoms, X is chlorine or bromine and y is zero, one, or a fraction between 0 and l, and organo-aluminium compounds of the formula Al~R11)(3-X)XX, in which Rll is an alkyl group having 2 to 12 carbon atoms, X is chlorine or bromine and x is zero or an in~eger or fraction not greater than 2;
- the said reduction reaction is performed in the presence or absence o~ an electron donor compound chosen from among a wide variety of organic compounds comprising at least one atom o oxygen, sulphur, nitrogen and/or phosphorus, such as for example amines, amide~, phosphines, sulphoxides, sulphones or ethers; as electron donor compound, one may choose in particular an aliphatic ether oxide of the formula ~120R13, in which R12 and R13 are identical or different alkyl groups having 1 to 12 carbon atoms;
- the relative molar quantities of the various compounds (support, titanium compound, organo-magnesium and/or organo-zinc and/or organo-aluminium compound, electron donor or ether oxide) are, in molar ratios, such that:
O Support:compound of titanium comprised between 1 and 50, and preferably comprised between 2.5 and 10;
. Organo-magnesium and/or organo-zinc and/or organo-aluMinium compound:titanium compound comprised between 0.1 and 3, pre~erably comprised between 0.5 and 1.5;
. Electron donor compound or ether oxide:titanium compound comprised between 0 and S, and preferably comprised between 0.1 and 1.5~
The precipitation is effected at a temperature comprised between -30C and 100C with agitation, in a liquid hydrocarbon medlum.
The use of the reagents in this precipitation may be carried out in various ways. One may, for example, introduce the reducing ~21;~5~
agent gradually (organo-magnesium or organo-zinc or organo-aluminium compound) into a liquid hydrocarbon medium containing the magnesium chloride support and the titanium compound. It is also possible to introduce gradually and simultaneously the reducing agent and the titanium compound into the liquid hydrocarbon medium containing the magnesiu~ chloride support. However, it is generally preferable to introduce the titanium compound gradually into the liquid hydrocarbon medium containing the magnesium chloride support and the reducing agent.
.
The catalysts obtained according to the present invention occur in the form of a powder, generally of a brownish~red colour, consisting of particles whose physical properties such as the spheroidal shape, surface appearance, mean diameter by mass and particle size distribution defined by the ratio Dm/Dn, are more or less identical to those of the particles of magnesium chloride support form which they originated.
After the evaporation of the liquid hydrocarbon medium in which ~hey were prepared, the catalysts according to the present invention are used for the copolymerisation of ethylene and hexene-1, using known techniques of polymerisation in the gas phase by means of a fluidised bed~
The copolymerisation is performed by using as co-catalyst an organo-metallic compound of a metal of Groups II and III of the Periodic Table, preferably an organo-aluminium or organo-aluminium halide compound. The components of the catalyst system must be used in proportions such that the atomic ratio of the quantity of metal of Groups II and III of the co-catalyst to the quantity of transition metal of Groups IV, V and VI of the catalyst is comprised between O.S and 200, preferably comprised between 1 and 50.
The catalytic systems used may be employed as such or after undergoing a pre-polymerisation operation. This pre-polymerisation operation leads to the production of particles whose dimensions and shapes are more or less homothetic to those of the initial catalyst, le the shapes of the prepolymer particles are, in effect, "magnified" derivatives of the original particles. The - ~23LZS(~
pre-polymerisation consists in bringing the catalyst and co-catalyst in contact with ethylene optionally in admixture with an alpha-olefin such as a hexene-l; the pre-polymerisation may advantageously be performed in two stages as described below. The S catalytic products thus obtained are particularly suited to the co-polymerisa~ion of ethylene and a hexene-l in a fluidised bed:
these products possess the dimensions, resistance to abrasion and reactivity which can be adapted to this mode of polymerisation, - making it possible to obtain a non-sticky powder, which in particular is free from co-polymers with a low melting point having both a low molecular weight and a relatively high content of hexene-l.
The commencement of the pre-polymerisation reaction (or the first stage of this reaction when one operates in two distinct lS stages) i9 suitably performed in suspension in an inert liqu~d medium.
This first pre-polymerisation stage is continued until each particle of catalyst comprises 0.1 to lOg of polyethylene or ethylene copolymer per milligramme atom of transition metal present in the catalyst. The prepolymerisation may then be continued either in suspension in a liquid hydrocarbon medium or in the dry state;
generally speaking it may be continued - whilst retaining a suitable activity in the catalyst - until 10 to 500 g of polyethylene or ethylene copolymer are obtained per milligramme atom of transition metal present in the catalyst.
The prepolymer obtained according to this process occurs in the form of a powder consisting of particles having a mean diameter by mass generally comprised between 80 and 300 microns, preferably comprised between 100 and 240 microns, and a particle size distribution such that the ratio Dm/Dn is less than or equal to 3, preferably comprised between 1.1 and 2.5; the prepolymer powder contains practically no particles with a diameter greater than 2 x Dm or less than 0.2 x Dm.
The copolymerisation in the gas phase by means of a fluidised bed may be performed according to conventional techniques of 5~
fluidlsed bed polymerisation and copolymerisation. However, the gaseous mixture providing the fluidisation comprises, in addition to the monomeric ethylene and hexene-l to be polymerised, an inert gas such as nitrogen, methane or ethane and optionally hydrogen to regulate the molecular weights of the copolymers obtained. The presence of an inert gas in this gaseous mixture appreciably improves the elimina~ion of the heat of reaction and favourably modifies the kinetics of copolymerisation. The speed of - fluidisation in the fluidised bed reactor is preferably high enough to facilitate homogenisation of the fluidised bed and to eliminate - effectively the heat given off by the copolymerisation~ without having recourse to any other means of homogenisation, especially mechanical. The speed of fluidisation is preferably equal to 5 to 10 times the minimum speed of fluidisation, that is ~o say generally lS compr~sed between about 40 and 80 cm/sec. In traversing the ~luidised bed only a part of the ethylene and hexene-1 polymerises in contact with the particles of the copolymers in course of growth. The gaseous mixture containing the fraction of ethylene and hexene-1 which has not reacted leaves the fluidised bed and passes through a cooling system intended eo eliminate the heat produced during the reaction, ~efore being recycled into the fluidised bed reactor by means of a compressor.
The copolymerisation is suitably performed at a temperature comprised between about 50C and 90C, preferably between 70C and Z5 90C, under a total pressure which may vary in the range generally comprised between 0.5 MPa and 4 MPa.
The partial pressure (pp) of the varlous constituents of the fluidised gas stream suitably comply with the ~ollowing ratios:
pp hexene-1 is in the range 0.05 MPa to 0.15 MPa:
pp hexene-1/pp ethylene is in the range 0.15 to 0.5:
pp hydrogen/pp ethylene is in the range 0~05 to 0.5:
pp iner~ gasttotal pressure is in the range 0.2 to 0.9.
The hexene-1 employed is preferably a hPxene-1 having a relatively low boiling point, for example 4-methyl-pentene-1.
~12~5~}
When operatlng according to the process as described above using in particular 4-methyl-pentene-1 as the hexene-1, one obtains copolymers containing approximately 4 to 15 per cent by weight of units derived from 4-methyl-pentene-1 and having densities comprised between 0.910 and 0.940.
These copolymers occur directly after the copolymerisation in the fluidised bed in the form of powders consisting of non-sticky particles, having a negligible proportion of copolymers with a low melting point having both a low molecular weight and a relatively high content of hexene-l.
These copolymer powders, which are easy to handle, have a comparatively high bulk density, comprised between 0.~0 and 0.45 g/cm3, preferably comprised between 0.35 and 0.45 g/cm3.
The copolymer particles making up these powders have a spheroidal shape, defined by the fact that if D and d are the large and small axis of these particles respectively, D/d is less than or equal to 1.3. These partlcles have mean diameter by mass, Dm, comprised between 300 and 1500 microns, preferably comprised between 500 and 1200 microns. The particle size distribution o these par~icles is such that the ratio Dm/Dn is less than or equal to 3.5, p~eferably comprised between 1.2 and 3. The width of particle size distribution of this powder wh-ich constitutes the fluidised bed depends not only on that of the prepoly~er used, but also on the mean residence time of the copolymer in the fluidised bed reactor, and also on the rate at which the catalytic system loses its activity during the copolymerisation reaction. In particular it is advsntageous in such a process to employ a catalyst system which loses its activity relatively rapidly during the copolymerisation reaction, in order to obtain a powder havlng the narrowest possible particle size distribution.
These copolymers of ethylene and 4-methyl-pen~ene-1 are also characterised by a very low degree of unsaturation, of less than 0,2 double bond per 1000 carbon atoms, which imparts to them an excellent stability.
sc~
By scanning differential calorimetric analysis, after re-heating to 200C, cooling at a speed of 16C per minute, and heating at the rate of 16C per minute, these copolymers show a - single melting point at a tempera~ure comprised between 116 and 128C, the fusion pattern characteristically showing a single peak at this temperature, which corresponds to a single distribution of the crystallite dimensionsO
The structure of the copolymers is also characterised by a very - small amount of long-chain branches (g*), which is expressed by a vzlue g* = (~ greater than or equal to 0.90, (~) being - the intrinsic viscosity of a given copolymer and (~1) being the intrinsic viscosity of a linear polyethylene having the same weLght average molecular weight as the said copolymer.
These copoly~ers whose melt index under 2.16 kg and at 190C, lS according to Standard ASTM D 1238, may vary between 0.1 and 30 g per lO minutes, have some particularly interesting applications in the production of films with a high mechanical strength.
Method for determinin~ the mean diameters by mass (Dm) and by number(Dn)_of particles. (Support, catalyst, prepolymer, polymer) According to the invention, the mean diameters by mass (Dm) and by number (Dn) of the particles of support, catalyst, prepolymer or polymer are measured from microscope readings by means of the OP~O~AX image analyser (Micro-~easurements Ltd., Great Britain), The mèasuring principle consists in obtaining from the experimental study by optical microscopy of a population of particles a table of absolute frequencies which gives the number (ni) of particles belonging to each category (i) of diameters, each category (i) being characterised by an intermediate diameter ~di), comprised between the limits of the said category. According to the approved French standard NF X 11-630 of June 1981, Dm and Dn are provided by the following equations:
O mean diameter by mass: Dm = ~ ni (di)_ di ni (di)3 . mean diameter by number: Dn = ni.di ~ ni O
~2~25~
. .
The ratio Dm/Dn characterises the particle size distribution;
it is sometimes referred to as "width of particle size distributlon".
The measurement by the OPTOMAX image analyser is performed by means of an inverted microscope which makes it possible to examine suspensions of particles at a magnification hetween 16 and 200 X. A
television camera picks up the images given by the inverted mlcroscope and transmlts them to a compu*er which analyses the images line by line and dot by dot on each line, in order to determine the dimensions or diameters of the particles and then to classify them.
The following non-restrictive Examples illustrate the invention.
Example 1 (a) Production of the catalyst Preparation of the support Into a 5-litre stainless steel reactor, provided with a system o agitation rotating at 750 revolutions per minute and containing 800 ml of n-hexane, there are introduced at ambient temperature (20C) and under a blanket of nitrogen: 1725 ml of a solution of butyloctylmagnesium in heptane containing 1500 milligramme-atoms of magnesium and 61 ml (300 millimoles) of di-isoamyl ether (DIAE).
The reactor is then heated to 50C and over 3 hours 313 ml of tertiary-butyl chloride (or 2850 millimoles) are poured ln drop by drop. At the end of this addition, the suspension is maintained at S0C for 3 hours and the precipitate (A) obtained is then washed five times with n-hexane, The washed product (A) constitu~es the support, its chemical composition is as follows per gramme-atom of magnesium:
- 1.97 gramme-atom of chlorine;
- 0.03 gramme equivalent of Mg-C bond;
- 0.02 mole of di-isoamyl ether.
On examination under the microscope it was possible to see that ~he magnesium chlorine support occurs in the form of a powder consisting of spheroidal particles (the mean ratio between large and 5~0 small axes, D/d of the particles is equal to 1.2), having a narrow particle size distribution defined by the ratio Dm/Dn = 1.29 where Dm = 33 microns; in addition it is found that more than 90 per cent by weight of the particles have a mean diameter comprised between 30 and 36 microns. The density of the product is equal to 1.9 and its specific surface area to 38 m2/g; the surface of the particles is smooth~
Preparation_of the catalyst , - Into 3000 ml of suspension in n-hexane of the washed product (A) obtainéd above, containing 1450 millimoles of MgC12, - there are added with agitation 82 ml of di-isoamyl ether and 400 ml of a 1.2 molar solut$on in n-hexane (or 480 millimoles) of diethyl aluminium chloride. The reactor is heated to 50C and over 2 hours 650 ml of a 0.6 molar so}ution of di-n-propoxy titanium dichloride (390 milli~oles) in n-hexane are added drop by drop. At the end of thls addition, the temperature is raised to 80C and it is maintained at this figure for 2 hours. The solid product is then washed five times with n-hexane to produce the catalyst (B) ready for use. Analysis of the catalyst shows that it contains per gramme ato~ of total titanium:
- 0.06 gramme-atom of tetravalent titanium;
- 0.94 gramme-atom of trivalent titanium;
- 3.85 gramme-atoms of magnesium;
- 9.87 gramme-atoms of chlorine;
- 0.20 gramme-atom of aluminium and - 0.11 gramme-molecule of di-isoamyl ether (DIAE).
It is brown-coloured powder consisting of particles of a more or less spherical shape, having a narrow particle size distribution in the image of the support employed and in particular such that more than ~0 per cent by weight of the particles have a mean diameter comprised between 32 and 38 microns, where Dm = 35 microns;
moreover, it is found that the ratio Dm:Dn of the catalyst particles is equal to 1.3; the surface of the particles is smooth.
~b) Production of the prepolymer Into a 5-litr~ stainless steel reactor, equipped with an 25~
agitation system rotati~lg at 750 revolutions per minute, there are introduced under nitrogen 2 litres of n-heptane which are heated to 70C. There are then introduced 48 ml of a solution of 1 mole per litre of tri-n-octylaluminium (TnOA) and a quantity of catalyst (B) prepared as above under (a)~ containing 12 milligramme-atoms of titanium.
There are then introduced into the reactor, hydrogen corresponding to a partial pressure equal to 0.08 MPa, then ethylene at a rate of 160 g/hr for 3 hours. At the end of the reaction, the whole is decanted into a rotary evaporator under a vacuum; in this way one obtains 480 g of a dry prepolymer powder (C), containing Q.025 milligramme-atom of titanium per gramme. This powder consists of spheroidal particles having a particle size distribution such that the ratio Dm/Dn = 1.3, where Dm = 140 microns; the surface of the particles iB smooth.
~c) Copolymerisatlon in a fluidised bed Into a fluidlsed bed reactor in stainless steel, with a ! diameter of 15 cm, opèrating with a rising gas mixture, actuated ata speed of 40 cm/sec, containing a molar percentage of 5X hydrogen, ~% 4-methyl-pentene-1, 22~ ethylene and 65% nitrogen, under a total pressure of 1 MPa and a temperature maintained at 80C, there are introduced first of all 3200 g-of a polyethylene powdPr which is perfectly anhydrous and deslccated for the charge powder, then, sequentially, 2.2g of prepolymer (C) prepared as above under (b) every 10 minutes.
By withdrawing from the reactor 640 g of powder per hour, the level of the fluidised bed remains constant. After 10 hours operation, the charge powder is practically completely replaced and one obtains a copolymar powder whose characteristics are as follows:
- More or less spherlcal particles, having a mean diameter by mass equal to 510 microns;
- Narrow particle size distribution, such that the ratio Dm/Dn = 1.7;
- Bulk density of the powder: 0.40 g/cm3;
_ Density of the copolymer: 0.920;
~L2S(~Q
- Melt index measured at 190C under a load of 2.16 kg (as per standard ASTM D 1238): l g/lO minutes;
- Content of units derived from 4-methyl-pentene-lo 9 per cent by we~ght;
- Titanium content: 25 ppm - Unsaturation level: 0.1 ethylenic double bond per 1000 carbon atoms;
- - Single melting point at 124C, determined by scanning differenti~
calorimetric a~ysis after re-heating to 200C, cooling at a rate of 16C perminute and heating at a rate of 16C per minute;
- Long chain branching: g* = 0.90.
Example 2 As support (A) there is employed a powder based on magnesium chloride consisting of spheroidal particles having a narrow particle size distribution, such that Dm/Dn = 2.3, where Dm = 23 microns;
this powder contains less than 0.05 per cent by weight of particles with a diameter 12ss than 4 microns; it shows a density equal to 1,9 and a specific surface area equal to 46 m2/g (BET); the surface of the particles is smooth.
(a) Production of the catalyst This is identical to that of Example l(a). Analysis of the catalyst (B) obtained gives per gramme-atom of total titanium:
- 0.94 gramme-atom of trivalent titanium, - 0.06 gramme-atom of tetravalent titanium, - 3.80 gramme-atoms of magnesium, - 9.85 gramme-atoms of chlorine, - 0~16 gramme-atom of aluminium and - 0.08 mole of di-isoamyl ether.
The catalyst (B) is a brown powder consisting of spheroidal particles having a particle size distribution such that Dm/Dn = 2.4 9 where Dm = 23 microns9 the particles of catalyst have a surface as smooth as the initial support.
(b) Production of the prepolymer This is identical to that of Example l(b), except for the fact that instead of introducing into the reactor ethylene at a rate of s~
160 gJhr, there is introduced a mixture of ethylene and
- 9.87 gramme-atoms of chlorine;
- 0.20 gramme-atom of aluminium and - 0.11 gramme-molecule of di-isoamyl ether (DIAE).
It is brown-coloured powder consisting of particles of a more or less spherical shape, having a narrow particle size distribution in the image of the support employed and in particular such that more than ~0 per cent by weight of the particles have a mean diameter comprised between 32 and 38 microns, where Dm = 35 microns;
moreover, it is found that the ratio Dm:Dn of the catalyst particles is equal to 1.3; the surface of the particles is smooth.
~b) Production of the prepolymer Into a 5-litr~ stainless steel reactor, equipped with an 25~
agitation system rotati~lg at 750 revolutions per minute, there are introduced under nitrogen 2 litres of n-heptane which are heated to 70C. There are then introduced 48 ml of a solution of 1 mole per litre of tri-n-octylaluminium (TnOA) and a quantity of catalyst (B) prepared as above under (a)~ containing 12 milligramme-atoms of titanium.
There are then introduced into the reactor, hydrogen corresponding to a partial pressure equal to 0.08 MPa, then ethylene at a rate of 160 g/hr for 3 hours. At the end of the reaction, the whole is decanted into a rotary evaporator under a vacuum; in this way one obtains 480 g of a dry prepolymer powder (C), containing Q.025 milligramme-atom of titanium per gramme. This powder consists of spheroidal particles having a particle size distribution such that the ratio Dm/Dn = 1.3, where Dm = 140 microns; the surface of the particles iB smooth.
~c) Copolymerisatlon in a fluidised bed Into a fluidlsed bed reactor in stainless steel, with a ! diameter of 15 cm, opèrating with a rising gas mixture, actuated ata speed of 40 cm/sec, containing a molar percentage of 5X hydrogen, ~% 4-methyl-pentene-1, 22~ ethylene and 65% nitrogen, under a total pressure of 1 MPa and a temperature maintained at 80C, there are introduced first of all 3200 g-of a polyethylene powdPr which is perfectly anhydrous and deslccated for the charge powder, then, sequentially, 2.2g of prepolymer (C) prepared as above under (b) every 10 minutes.
By withdrawing from the reactor 640 g of powder per hour, the level of the fluidised bed remains constant. After 10 hours operation, the charge powder is practically completely replaced and one obtains a copolymar powder whose characteristics are as follows:
- More or less spherlcal particles, having a mean diameter by mass equal to 510 microns;
- Narrow particle size distribution, such that the ratio Dm/Dn = 1.7;
- Bulk density of the powder: 0.40 g/cm3;
_ Density of the copolymer: 0.920;
~L2S(~Q
- Melt index measured at 190C under a load of 2.16 kg (as per standard ASTM D 1238): l g/lO minutes;
- Content of units derived from 4-methyl-pentene-lo 9 per cent by we~ght;
- Titanium content: 25 ppm - Unsaturation level: 0.1 ethylenic double bond per 1000 carbon atoms;
- - Single melting point at 124C, determined by scanning differenti~
calorimetric a~ysis after re-heating to 200C, cooling at a rate of 16C perminute and heating at a rate of 16C per minute;
- Long chain branching: g* = 0.90.
Example 2 As support (A) there is employed a powder based on magnesium chloride consisting of spheroidal particles having a narrow particle size distribution, such that Dm/Dn = 2.3, where Dm = 23 microns;
this powder contains less than 0.05 per cent by weight of particles with a diameter 12ss than 4 microns; it shows a density equal to 1,9 and a specific surface area equal to 46 m2/g (BET); the surface of the particles is smooth.
(a) Production of the catalyst This is identical to that of Example l(a). Analysis of the catalyst (B) obtained gives per gramme-atom of total titanium:
- 0.94 gramme-atom of trivalent titanium, - 0.06 gramme-atom of tetravalent titanium, - 3.80 gramme-atoms of magnesium, - 9.85 gramme-atoms of chlorine, - 0~16 gramme-atom of aluminium and - 0.08 mole of di-isoamyl ether.
The catalyst (B) is a brown powder consisting of spheroidal particles having a particle size distribution such that Dm/Dn = 2.4 9 where Dm = 23 microns9 the particles of catalyst have a surface as smooth as the initial support.
(b) Production of the prepolymer This is identical to that of Example l(b), except for the fact that instead of introducing into the reactor ethylene at a rate of s~
160 gJhr, there is introduced a mixture of ethylene and
4-Methyl-pentene-1 containing 3.5 per cent by weight of 4-methyl-pentene-l,at a rate of 160 g per hour. One obtains 480 g of a prepolymer powder (C) having a density of 0.94 and containing 0.025 milligramme-atom of titanium per gramme. This powder consists of spheroidal particles having a particle si7e distribution such that the ratio Dm/Dn = 2.4, where Dm = 100 microns; the surface of the particles ~s smooth.
(c) Copolymerisation in a fluidised bed This is identical to that of Example l~c), except for the fact - that instead of employing a gaseous mixture containing a molar percentage of 5~ hydrogen, 8% 4-methyl-pentene-l, 22% ethylene and 65% nitrogen, there is employed a gaseous mixture containing 5%
hydrogen, 7% 4-methyl-pentene-l, 23% ethylene and 65% nitrogen as a molar percentage. There are withdrawn from the reactor 680g of powder per hour, whilst ~aintaining the fluidised bed at a constant height. A~ter 10 hours of continuous reaction, there is obtained a copolymer powder whose characterlstics are as follows~
- Particles of spheroidal shape having a mean diameter by mass equal to 370 microns.
- Particle si~e distribution such that the ratio Dm/Dn = 2.8.
- Bulk density of the powder: 0.42 g/cm3.
- Density of copolymer: 0.925.
- Melt index measured at 190C under a load of 2.16 kg:
0.9 g/10 minutes.
- Content of units derived from 4-methyl-pentene-1: 8 per cent by weight.
- Tltanium content: 23 ppm.
- Unsaturation level: 0.13 ethylenic double bond per 1000 carbon atoms.
- Single melting point at 120C, determined by scanning differential calorimetric analysis, after reheating to 200C, cooling at a rate of 16C per minute and heating at a rate of 16~C
per minute.
- Long chain branching: g* = 0.97.
~Z~SQl~
Example 3 As support (A) there is employed a powder based on magnesium chloride, consisting of spheroidal particles having a narrow - particle size distribution, such that the ratio Dm/Dn = 1.1, where Dm = 52 microns; it is found that m~re than gb per cent by weight of the particles have a mean diameter comprised between 47 and 57 microns; the density of the product is equal to 1.9 and its specific surface area to 38 m2/g (BET); the surface of tha - particles is smooth.
(a) _oduction of the catalyst This is identical to that of ~xample 1(a). Analysis of the catalyst (B) obtained gives per gramme-atom of total titanium:
- 0.95 gramme-atom of trivalent titanium, - 0.05 gramme-atom of tetravalent titanium, - 3.80 gramme-atoms of magnesium, ~ 9.95 gramme-atoms of chlorine, - 0~20 gramme-atom of aluminium and - 0.11 mole o di-isoamyl ether.
The catalyst (B) is a brown powder consisting of spheroidal particles having a particle size distribution such that Dm/Dn = 1.2, where Dm = 55 microns; the catalyst particles have a smooth surface.
(b) Production of prepolymer PrepolymerisatioD (first stage) Into a S-litre stainless steel reactor, equipped with an agitation system rotating at 750 revolutions per minute and containing 2 litres of n-hexane heated to 50C, there are introduced under a blanket of nitrogen 100 millimoles of tri-n-octylaluminium (TnOA) and a suspension of the catalyst (B) in hexane containing 500 milligramme-atoms of titanium. The reactor is heated to 60C
and the ethylene is introduced into it at a constant rate equal to 167 g/hr, over 3 hours. At the end of the reaction the whole is decanted into a rotary evaporator under a vacuum; in this way 820 g of dry powder (C') are obtainad of a prepolymer of a light-brown colour, consisting of particles with a mean diameter by mass equal to 66 microns and with a narrow particle si~e distribution, such 17 ~ 5~
that the ratio Dm/Dn = 1.2. The powder (C') is stored under nitrogen.
Prepolymerisation (second stage) Into a fluidised bed reactor with a diameter of 15 cm operating at a gas speed of 10 cm/sec, under partial pressures of 0.8 MPa nitrogen, 0.1 MPa hydrogen, 0.02 MPa 4-methyl-pentene 1 and 0.08 MPa ethylene, there are introduced, evPry 6 minutes, 1lg of the powder (C') and continuously 25 g/hr of pure TnOA, into the lower half of the bed which is maintained at 70C. In a series of withdrawals approximately 4 kg/hr are collected of a slightly beige-tinted powder which contains 0.017 milligramme-atom of titanium per gramme, for a residence time of half an hour in the reactor, and showing a particle size distribution such that the ratio Dm/Dn = 1.3, where Dm a 260 microns, and having a density of 0.93.
(c) Copolyme~_ ation ln a fluidised bed Thi~ is ldentical to that of Example 1(c), except for the fact that instead of employing ~he gaseous mixture actuated a~ a speed of 40 cm/sec, it ls employed at a speed of 60 cm/sec. 650g of powder are withdrawn from the reactor per hour, whilst maintaining the fluidised bed at a constant height. After 10 hours of continuous reaction, a copolymer powder is obtained whose characteristics are as follows:
- Particles of a spheroidal shape, having a mean diameter by mass equal to 950 microns.
- Particle si~e distribution such that the ratio Dm/Dn = 1.5.
- Bulk density of the powder: 0.41 g/cm3.
- Densi~y of copolymer: 0.919.
- Melt index, neasured at 190C under a load of 2.16 kg:
1 g/10 minutes.
- Content of units derived from 4-methyl-pentene-1: 9 per cent by weight.
- Titanium content: 16 ppm.
- Unsaturation level: 0.15 ethylenic double bond per 1000 carbon atoms.
- Single melting point at 118C, determined by scanning 5cl~
differential calorimetric analysis, after re-heating to 200C, cooling at a rate of 16C per minute and heating at a rate of 16C
per mdnu~e.
- Long chain branching: g* = 0.95.
~ Method for determininq the lona-chain branches ratio, q*.
_ _ _ _ In the equation 9~ the intrinsic viscosity (~ ) of the copolymer is measured in the trichlorobenzene at 135C.
On the other hand, the intrinsic viscosïty (~ )l of the linear - polyethylene, having the same weight average molecular weight, Mw, as the said copolymer, is calculated according to the following equation of MARK-HOUWINK's type : (7 )1 = 6.02 x lO 4 x (Mw)0 69 ;
the weight average molecular weight, Mw~ of the copolymer is deter-mined by gel permeation chromatography (GPC), the fractionating columns being calibrated by means of linear polyethylene samples.
(c) Copolymerisation in a fluidised bed This is identical to that of Example l~c), except for the fact - that instead of employing a gaseous mixture containing a molar percentage of 5~ hydrogen, 8% 4-methyl-pentene-l, 22% ethylene and 65% nitrogen, there is employed a gaseous mixture containing 5%
hydrogen, 7% 4-methyl-pentene-l, 23% ethylene and 65% nitrogen as a molar percentage. There are withdrawn from the reactor 680g of powder per hour, whilst ~aintaining the fluidised bed at a constant height. A~ter 10 hours of continuous reaction, there is obtained a copolymer powder whose characterlstics are as follows~
- Particles of spheroidal shape having a mean diameter by mass equal to 370 microns.
- Particle si~e distribution such that the ratio Dm/Dn = 2.8.
- Bulk density of the powder: 0.42 g/cm3.
- Density of copolymer: 0.925.
- Melt index measured at 190C under a load of 2.16 kg:
0.9 g/10 minutes.
- Content of units derived from 4-methyl-pentene-1: 8 per cent by weight.
- Tltanium content: 23 ppm.
- Unsaturation level: 0.13 ethylenic double bond per 1000 carbon atoms.
- Single melting point at 120C, determined by scanning differential calorimetric analysis, after reheating to 200C, cooling at a rate of 16C per minute and heating at a rate of 16~C
per minute.
- Long chain branching: g* = 0.97.
~Z~SQl~
Example 3 As support (A) there is employed a powder based on magnesium chloride, consisting of spheroidal particles having a narrow - particle size distribution, such that the ratio Dm/Dn = 1.1, where Dm = 52 microns; it is found that m~re than gb per cent by weight of the particles have a mean diameter comprised between 47 and 57 microns; the density of the product is equal to 1.9 and its specific surface area to 38 m2/g (BET); the surface of tha - particles is smooth.
(a) _oduction of the catalyst This is identical to that of ~xample 1(a). Analysis of the catalyst (B) obtained gives per gramme-atom of total titanium:
- 0.95 gramme-atom of trivalent titanium, - 0.05 gramme-atom of tetravalent titanium, - 3.80 gramme-atoms of magnesium, ~ 9.95 gramme-atoms of chlorine, - 0~20 gramme-atom of aluminium and - 0.11 mole o di-isoamyl ether.
The catalyst (B) is a brown powder consisting of spheroidal particles having a particle size distribution such that Dm/Dn = 1.2, where Dm = 55 microns; the catalyst particles have a smooth surface.
(b) Production of prepolymer PrepolymerisatioD (first stage) Into a S-litre stainless steel reactor, equipped with an agitation system rotating at 750 revolutions per minute and containing 2 litres of n-hexane heated to 50C, there are introduced under a blanket of nitrogen 100 millimoles of tri-n-octylaluminium (TnOA) and a suspension of the catalyst (B) in hexane containing 500 milligramme-atoms of titanium. The reactor is heated to 60C
and the ethylene is introduced into it at a constant rate equal to 167 g/hr, over 3 hours. At the end of the reaction the whole is decanted into a rotary evaporator under a vacuum; in this way 820 g of dry powder (C') are obtainad of a prepolymer of a light-brown colour, consisting of particles with a mean diameter by mass equal to 66 microns and with a narrow particle si~e distribution, such 17 ~ 5~
that the ratio Dm/Dn = 1.2. The powder (C') is stored under nitrogen.
Prepolymerisation (second stage) Into a fluidised bed reactor with a diameter of 15 cm operating at a gas speed of 10 cm/sec, under partial pressures of 0.8 MPa nitrogen, 0.1 MPa hydrogen, 0.02 MPa 4-methyl-pentene 1 and 0.08 MPa ethylene, there are introduced, evPry 6 minutes, 1lg of the powder (C') and continuously 25 g/hr of pure TnOA, into the lower half of the bed which is maintained at 70C. In a series of withdrawals approximately 4 kg/hr are collected of a slightly beige-tinted powder which contains 0.017 milligramme-atom of titanium per gramme, for a residence time of half an hour in the reactor, and showing a particle size distribution such that the ratio Dm/Dn = 1.3, where Dm a 260 microns, and having a density of 0.93.
(c) Copolyme~_ ation ln a fluidised bed Thi~ is ldentical to that of Example 1(c), except for the fact that instead of employing ~he gaseous mixture actuated a~ a speed of 40 cm/sec, it ls employed at a speed of 60 cm/sec. 650g of powder are withdrawn from the reactor per hour, whilst maintaining the fluidised bed at a constant height. After 10 hours of continuous reaction, a copolymer powder is obtained whose characteristics are as follows:
- Particles of a spheroidal shape, having a mean diameter by mass equal to 950 microns.
- Particle si~e distribution such that the ratio Dm/Dn = 1.5.
- Bulk density of the powder: 0.41 g/cm3.
- Densi~y of copolymer: 0.919.
- Melt index, neasured at 190C under a load of 2.16 kg:
1 g/10 minutes.
- Content of units derived from 4-methyl-pentene-1: 9 per cent by weight.
- Titanium content: 16 ppm.
- Unsaturation level: 0.15 ethylenic double bond per 1000 carbon atoms.
- Single melting point at 118C, determined by scanning 5cl~
differential calorimetric analysis, after re-heating to 200C, cooling at a rate of 16C per minute and heating at a rate of 16C
per mdnu~e.
- Long chain branching: g* = 0.95.
~ Method for determininq the lona-chain branches ratio, q*.
_ _ _ _ In the equation 9~ the intrinsic viscosity (~ ) of the copolymer is measured in the trichlorobenzene at 135C.
On the other hand, the intrinsic viscosïty (~ )l of the linear - polyethylene, having the same weight average molecular weight, Mw, as the said copolymer, is calculated according to the following equation of MARK-HOUWINK's type : (7 )1 = 6.02 x lO 4 x (Mw)0 69 ;
the weight average molecular weight, Mw~ of the copolymer is deter-mined by gel permeation chromatography (GPC), the fractionating columns being calibrated by means of linear polyethylene samples.
Claims (24)
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:
1. Process for the preparation of copolymers of ethylene and hexene-1 having a density comprised between 0.910 and 0.940, characterised in that it comprises a copolymerisation of ethylene and hexene-1 in the gaseous state in admixture with an inert gas, the gaseous mixture circulating from bottom to top through a fluidised bed of the copolymer being formed, the copolymerisation being effected at a temperature between 50 and 90°C, in the presence of a catalyst system comprising on the one hand a co-catalyst consisting of at least one organo-metallic compound of a metal of Groups II and III of the Periodic Table of Elements and on the other hand a catalyst comprising a support based essentially on magnesium chloride, consisting of particles of spheroidal shape having a mean diameter by mass comprised be-tween 10 and 100 microns and showing a particle size distribution such that the ratio Dm/Dn of the mean diameter by mass, Dm, to the mean diameter by number, Dn, of the particles is less than or equal to 3, on to which support there has been precipitated a derivative of a transition metal of Groups IV, V and VI of the Periodic Table of Elements which is known for its catalytic properties in the polymerisation and copolymerisation of alpha-olefins, the partial pressure (pp) of the various constituents of the gaseous mixture being such that:
pp hexene-1 is in the range 0.05 MPa to 0.15 MPa:
pp heXene-1/pp ethylene is in the range 0.15 to 0.5:
pp inert gas/total pressure is in the range 0.2 to 0.9.
pp hexene-1 is in the range 0.05 MPa to 0.15 MPa:
pp heXene-1/pp ethylene is in the range 0.15 to 0.5:
pp inert gas/total pressure is in the range 0.2 to 0.9.
2. Process in accordance with claim 1, characterised in that the copolymerisation is performed at a temperature between 70°C and 90°C.
3. Process in accordance with claim 1, characterised in that the organo-metallic compound of a metal of Groups II and III is an organo-aluminium compound or organoaluminium halide compound.
4. Process in accordance with claim 1, characterised in that the support shows a particle size distribution such that the ratio Dm/Dn is between 1.1 and 2.5.
5. Process in accordance with claim 1, characterised in that the support shows a particle size distribution such that the ratio Dm/Dn is between 1.1 and 1.5.
6. Process in accordance with claim 1, characterised in that the support shows a particle size distribution such that more than 90 per cent by weight of the particles are in the bracket Dm?10%.
7. Process in accordance with claim 1, characterised in that the support contains a compound having at least one Mg-C
bond and one electron donor compound, and has a density between 1.6 and 2.2.
bond and one electron donor compound, and has a density between 1.6 and 2.2.
8. Process in accordance with claim 1, characterised in that the support has a specific surface area comprised between 20 and 60 m2/g (BET).
9. Process in accordance with claim 1, characterised in that the derivative of the transition metal is a titanium compound.
10. Process in accordance with claim 9, in which the precipitation of the titanium compound to the support is effected by reducing a titanium compound at maximum valency of the formula Ti(OR7)4-nXn in which R7 is an alkyl group containing from 2 to 6 carbon atoms, X is a chlorine or bromine atom and n is an integer or fraction from 1 to 4 inclusive by means of a reducing agent chosen from among the organo-magnesium compounds of the formula R8MgR9 in which R8 and R9 are alkyl groups containing from 2 to 12 carbon atoms, organo-zinc compounds of the formula Zn(R10)(2-y)Xy in which R10 is an alkyl group having 2 to 12 carbon atoms, X is chlorine or bromine and y is zero, one or a fraction between 0 and 1, and organoaluminium compounds of the formula Al(R11)(3-x)Xx in which R11 is an alkyl group having from 2 to 12 carbon atoms, X is chlorine or bromine and x is zero, an interger or a fraction not greater than 2, the relative molar quantities of the various compounds (support of magnesium chloride and possibly of aluminium chloride, titanium compounds, organo-magnesium and/or organo-zinc and/or organo-aluminium compound, electron donor) are such that:
? Support: titanium compound is between 1 and 50, ? Organo-magnesium and/or organo-zinc and/or organo-aluminium compound: titanium compound is between 0.1 and 3, ? Electron donor compound: titanium compound is between 0 and 5.
? Support: titanium compound is between 1 and 50, ? Organo-magnesium and/or organo-zinc and/or organo-aluminium compound: titanium compound is between 0.1 and 3, ? Electron donor compound: titanium compound is between 0 and 5.
11. Process according to claim 8, wherein the support has a smooth surface.
12. Process according to claim 10, wherein said reduction is effected in the presence of an electron donor compound which is an organic compound having at least one atom of oxygen, sul-phur, nitrogen or phosphorus.
13. Process according to claim 10, wherein said relative molar quantities are such that:
? Support: titanium compound is between 2.5 and 10;
? Organo-magnesium and/or organo-zinc and/or organo-aluminium compound: titanium compound is between 0.5 and 1.5;
and ? Electron donor compound: titanium compound is between 0.1 and 1.5.
? Support: titanium compound is between 2.5 and 10;
? Organo-magnesium and/or organo-zinc and/or organo-aluminium compound: titanium compound is between 0.5 and 1.5;
and ? Electron donor compound: titanium compound is between 0.1 and 1.5.
14. Process in accordance with claim 10, in which the reduction is performed in the presence or absence of an aliphatic ether oxide of the formula R12OR13 in which R12 and R13 are identical or different and are chosen from among the alkyl groups having 1 to 12 carbon atoms, the relative molar quantities of the various compounds (support of magnesium chloride, titanium compound, organo-magnes-ium and/or organo-zinc and/or organo-aluminium compound, ether oxide) are such that:
? Support: titanium compound is between 1 and 50, ? Organo-magnesium and/or organo-zinc and/or organo-aluminium compound: titanium compound is between 0.1 and 3;
? Ether oxide: titanium compound is between 0 and S.
? Support: titanium compound is between 1 and 50, ? Organo-magnesium and/or organo-zinc and/or organo-aluminium compound: titanium compound is between 0.1 and 3;
? Ether oxide: titanium compound is between 0 and S.
15. Process according to claim 14,wherein said relative molar quantities are such that:
? Support: titanium compound is between 2.5 and 10, ? Organo-magnesium and/or organo-zinc and/or organo-aluminium compound: titanium compound is between 0.5 and 1.5;
and ? Ether oxide: titanium compound is between 0.1 and 1.5.
? Support: titanium compound is between 2.5 and 10, ? Organo-magnesium and/or organo-zinc and/or organo-aluminium compound: titanium compound is between 0.5 and 1.5;
and ? Ether oxide: titanium compound is between 0.1 and 1.5.
16. Process according to claim 1, wherein said inert gas is nitrogen, methane or ethane.
17. Process according to claim 1, wherein the copolymeri-sation is effected in the presence of hydrogen, wherein pp hydrogen/pp ethylene is in the range 0.05 to 0.5.
18. Process according to claim 1, wherein the support further comprises an aluminium chloride.
19. Process in accordance with claim 1, characterized in that the copolymerisation is performed in the presence of a catalyst system in which the atomic ratio of the quantity of metals of Groups II and III of the co-catalyst to the quantity of transition metal of Groups IV, V and VI of the catalyst is between 1 and 50.
20. Process in accordance with claim 1, characterised in that before the said co-polymerisation is carried out, the catalyst is subjected to a pre-polymerisation of the ethylene or a pre-co-polymerisation of the ethylene and an alpha-olefin so as to obtain from 0.1 to 500 g of polymer or co-polymer per milligramme-atom of transition metal.
21. Process in accordance with claim 1, characterised in that the co-polymerisation conditions in the fluidised bed are such that the particles of pre-polymer and co-polymer during formation are maintained in the fluidised state solely by means of a rising gas current containing the ethylene and hexene-1 to be polymerised and having a speed between 40 and 80 cm/sec.
22. A co-polymer which can be obtained by the process according to claim 1 in which the hexene-1 is 4-methyl-pentene-1, characterised in that it has:
(a) a content of units derived from 4-methyl-pentene-1 between 4 and 15% by weight.
(b) A density between 0.910 and 0.940, (c) a bulk density between 0.35 and 0.45 g/cm3, (d) an unsaturation level of less than 0.2 double bonds per 1,000 carbon atoms, (e) a single melting point between 116°C and 128°C, determined by scanning differential calorimetric analysis after re-heating to 200°C, cooling at the rate of 16°C per minute and heating at the rate of 16°C per minute, (f) a structure with a small amount of long-chain branches such that g* is greater than or equal to 0.90 wherein g* is the ratio n/n1, n being the intrinsic viscosity of the co-polymer and n1 being the intrinsic viscosity of a linear polyethylene having the same weight average molecular weight as the said co-polymer.
(a) a content of units derived from 4-methyl-pentene-1 between 4 and 15% by weight.
(b) A density between 0.910 and 0.940, (c) a bulk density between 0.35 and 0.45 g/cm3, (d) an unsaturation level of less than 0.2 double bonds per 1,000 carbon atoms, (e) a single melting point between 116°C and 128°C, determined by scanning differential calorimetric analysis after re-heating to 200°C, cooling at the rate of 16°C per minute and heating at the rate of 16°C per minute, (f) a structure with a small amount of long-chain branches such that g* is greater than or equal to 0.90 wherein g* is the ratio n/n1, n being the intrinsic viscosity of the co-polymer and n1 being the intrinsic viscosity of a linear polyethylene having the same weight average molecular weight as the said co-polymer.
23. A co-polymer as claimed in claim 22, characterised in that it occurs in the form of spheroidal particles having a mean diameter by mass between 300 and 1500 microns and a part-icle size distribution such that the ratio Dm:Dn is less than or equal to 3.5.
24. A co-polymer as claimed in claim 23, characterized in that it has a particle size distribution such that the ratio Dm:Dn is between 1.2 and 3.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| FR8215162A FR2532649B1 (en) | 1982-09-07 | 1982-09-07 | COPOLYMERIZATION OF ETHYLENE AND HEXENE-1 IN A FLUIDIZED BED |
| FR8215162 | 1982-09-07 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1212500A true CA1212500A (en) | 1986-10-07 |
Family
ID=9277260
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000436128A Expired CA1212500A (en) | 1982-09-07 | 1983-09-06 | Copolymerization of ethylene and hexene-1 in fluidised bed |
Country Status (14)
| Country | Link |
|---|---|
| US (2) | US4642328A (en) |
| EP (1) | EP0102895B2 (en) |
| JP (1) | JPS5964611A (en) |
| AT (1) | ATE17742T1 (en) |
| AU (1) | AU563037B2 (en) |
| CA (1) | CA1212500A (en) |
| CS (1) | CS401491A3 (en) |
| DE (1) | DE3362025D1 (en) |
| ES (1) | ES525448A0 (en) |
| FI (1) | FI75849C (en) |
| FR (1) | FR2532649B1 (en) |
| NO (1) | NO162159C (en) |
| NZ (1) | NZ205423A (en) |
| PT (1) | PT77296B (en) |
Families Citing this family (46)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4558105A (en) * | 1983-12-07 | 1985-12-10 | Chemplex Company | Copolymerization of ethylene |
| FR2563833B1 (en) * | 1984-05-02 | 1986-09-05 | Bp Chimie Sa | PROCESS OF COPOLYMERIZATION IN A FLUIDIZED BED OF ETHYLENE, PROPYLENE AND / OR BUTENE-1 AND ALPHA-OLEFINS CONTAINING 5 TO 8 CARBON ATOMS |
| US5034479A (en) * | 1987-10-22 | 1991-07-23 | Union Carbide Chemicals And Plastics Technology Corporation | Process for reducing sheeting during polymerization of alpha-olefins |
| US5830087A (en) * | 1995-06-26 | 1998-11-03 | Lisco, Inc. | Multi-layer golf ball |
| US6025448A (en) | 1989-08-31 | 2000-02-15 | The Dow Chemical Company | Gas phase polymerization of olefins |
| US5272236A (en) * | 1991-10-15 | 1993-12-21 | The Dow Chemical Company | Elastic substantially linear olefin polymers |
| US6538080B1 (en) | 1990-07-03 | 2003-03-25 | Bp Chemicals Limited | Gas phase polymerization of olefins |
| US5783638A (en) | 1991-10-15 | 1998-07-21 | The Dow Chemical Company | Elastic substantially linear ethylene polymers |
| US5847053A (en) * | 1991-10-15 | 1998-12-08 | The Dow Chemical Company | Ethylene polymer film made from ethylene polymer blends |
| US5677383A (en) * | 1991-10-15 | 1997-10-14 | The Dow Chemical Company | Fabricated articles made from ethylene polymer blends |
| US5278272A (en) | 1991-10-15 | 1994-01-11 | The Dow Chemical Company | Elastic substantialy linear olefin polymers |
| US5525695A (en) | 1991-10-15 | 1996-06-11 | The Dow Chemical Company | Elastic linear interpolymers |
| US5395471A (en) | 1991-10-15 | 1995-03-07 | The Dow Chemical Company | High drawdown extrusion process with greater resistance to draw resonance |
| US5582923A (en) | 1991-10-15 | 1996-12-10 | The Dow Chemical Company | Extrusion compositions having high drawdown and substantially reduced neck-in |
| US5674342A (en) | 1991-10-15 | 1997-10-07 | The Dow Chemical Company | High drawdown extrusion composition and process |
| FR2689133A1 (en) * | 1992-03-27 | 1993-10-01 | Atochem Elf Sa | Catalyst for the polymerization of olefins, process for obtaining it. |
| PT681592E (en) * | 1993-01-29 | 2001-01-31 | Dow Chemical Co | ETHYLENE INTERPOLIMERIZATIONS |
| JP3365668B2 (en) * | 1994-03-02 | 2003-01-14 | 三井化学株式会社 | Ethylene polymer, solid titanium catalyst component for ethylene polymerization, ethylene polymerization catalyst containing the catalyst component, and method for producing ethylene polymer using the catalyst |
| US5741195A (en) * | 1994-09-30 | 1998-04-21 | Lisco, Inc. | High visibility inflated game ball |
| US5792534A (en) | 1994-10-21 | 1998-08-11 | The Dow Chemical Company | Polyolefin film exhibiting heat resistivity, low hexane extractives and controlled modulus |
| US5869575A (en) * | 1995-08-02 | 1999-02-09 | The Dow Chemical Company | Ethylene interpolymerizations |
| US6114477A (en) * | 1996-02-09 | 2000-09-05 | Exxon Chemical Patents Inc. | Polymerization process |
| US6552126B2 (en) | 1997-03-03 | 2003-04-22 | Spalding Sports Worldwide, Inc. | Golf ball cover containing a blend of ionomer and plastomer, and method of making same |
| KR100240519B1 (en) * | 1997-09-11 | 2000-01-15 | 유현식 | Chealate catalyst for polymerising olefin |
| GB9800245D0 (en) * | 1998-01-07 | 1998-03-04 | Bp Chem Int Ltd | Novel polymers |
| KR100524293B1 (en) | 1999-05-27 | 2005-10-26 | 삼성토탈 주식회사 | A catalyst for ethylene homo- and co-polymerization |
| ATE276281T1 (en) | 1999-10-23 | 2004-10-15 | Samsung General Chemicals Co | IMPROVED CATALYST FOR OLEFIN HOMO- AND CO-POLYMERIZATION |
| KR100361224B1 (en) * | 1999-12-01 | 2002-11-29 | 삼성종합화학주식회사 | Method for preparing catalyst for ethylene homo- and co-polymerization |
| KR100359932B1 (en) | 2000-06-15 | 2002-11-07 | 삼성종합화학주식회사 | A catalyst for ethylene homo- and copolymerization |
| KR100387734B1 (en) * | 2000-06-17 | 2003-06-18 | 삼성종합화학주식회사 | Catalyst and process for polymerization of olefin |
| KR100389477B1 (en) * | 2000-11-09 | 2003-06-27 | 삼성종합화학주식회사 | A method for producing ethylene homo- and co-polymer |
| KR100389476B1 (en) * | 2000-11-09 | 2003-06-27 | 삼성종합화학주식회사 | A method for producing ethylene homo- and co-polymer |
| KR100389475B1 (en) * | 2000-11-09 | 2003-06-27 | 삼성종합화학주식회사 | Preparation method of catalyst for ethylene polymeration or copolymeration |
| KR100389962B1 (en) * | 2000-11-10 | 2003-07-02 | 삼성종합화학주식회사 | Preparation method of catalyst for ethylene polymeration or copolymeration |
| KR100421551B1 (en) * | 2000-12-16 | 2004-03-09 | 삼성아토피나주식회사 | Catalyst obtained by prepolymerization of polyolefin and olefin polymerization method using the same |
| ATE305490T1 (en) * | 2000-12-22 | 2005-10-15 | Samsung General Chemicals Co | POLYOLEFIN RESIN COMPOSITION |
| EP1358223A4 (en) * | 2000-12-22 | 2005-01-05 | Samsung General Chemicals Co | Chelate catalyst for olefin polymerization and olefin polymerization method using the same |
| JP2004516379A (en) * | 2000-12-22 | 2004-06-03 | サムソン ジェネラル ケミカルズ カンパニー リミテッド | Polypropylene resin composition with improved surface hardness and scratch resistance |
| CN1220789C (en) * | 2000-12-22 | 2005-09-28 | 三星综合化学株式会社 | Flame retardant polypropylene resin composition |
| KR100496776B1 (en) * | 2001-06-21 | 2005-06-22 | 삼성토탈 주식회사 | Catalyst for polymerization and copolymerization of ethylene |
| KR100530794B1 (en) * | 2001-06-21 | 2005-11-23 | 삼성토탈 주식회사 | Catalyst for polymerization and copolymerization of ethylene |
| KR100530795B1 (en) * | 2001-12-26 | 2005-11-23 | 삼성토탈 주식회사 | A method for ethylene homo- and copolymerization |
| US6841498B2 (en) * | 2003-02-12 | 2005-01-11 | Formosa Plastic Corporation, U.S.A. | Catalyst system for ethylene (co)polymerization |
| US7211534B2 (en) * | 2003-02-12 | 2007-05-01 | Formosa Plastics Corporation, U.S.A. | Preparation of a magnesium halide support for olefin polymerization and a catalyst composition using the same |
| US7647964B2 (en) * | 2005-12-19 | 2010-01-19 | Fairmount Minerals, Ltd. | Degradable ball sealers and methods for use in well treatment |
| US7754834B2 (en) | 2007-04-12 | 2010-07-13 | Univation Technologies, Llc | Bulk density promoting agents in a gas-phase polymerization process to achieve a bulk particle density |
Family Cites Families (15)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| USB632416I5 (en) * | 1956-03-01 | 1976-03-09 | ||
| US3953414A (en) * | 1972-09-13 | 1976-04-27 | Montecatini Edison S.P.A., | Catalysts for the polymerization of olefins to spherically shaped polymers |
| IT1042667B (en) * | 1975-09-18 | 1980-01-30 | Montedison Spa | CATALYSTS FOR THE POLYMERIZATION OF SEROIDAL POLYMER OLEFINS |
| JPS5952643B2 (en) * | 1977-01-27 | 1984-12-20 | 三井化学株式会社 | ethylene copolymer |
| GB1603724A (en) * | 1977-05-25 | 1981-11-25 | Montedison Spa | Components and catalysts for the polymerisation of alpha-olefins |
| US4302565A (en) * | 1978-03-31 | 1981-11-24 | Union Carbide Corporation | Impregnated polymerization catalyst, process for preparing, and use for ethylene copolymerization |
| JPS54133584A (en) * | 1978-04-07 | 1979-10-17 | Sumitomo Chem Co Ltd | Preparation of highly crystalline olefin polymer |
| IT1098272B (en) * | 1978-08-22 | 1985-09-07 | Montedison Spa | COMPONENTS, CATALYSTS AND CATALYSTS FOR THE POLYMERIZATION OF ALPHA-OLEFINS |
| JPS5558210A (en) * | 1978-10-26 | 1980-04-30 | Nippon Oil Co Ltd | Production of copolymer |
| US4482687A (en) * | 1979-10-26 | 1984-11-13 | Union Carbide Corporation | Preparation of low-density ethylene copolymers in fluid bed reactor |
| JPS57105411A (en) * | 1980-12-23 | 1982-06-30 | Mitsubishi Petrochem Co Ltd | Ethylenic copolymer |
| US4396748A (en) * | 1981-10-22 | 1983-08-02 | The Dow Chemical Company | Process for polymerizing alpha-olefins |
| US4522987A (en) * | 1982-07-09 | 1985-06-11 | Phillips Petroleum Company | Low density polyethylene |
| JPS5920308A (en) * | 1982-07-26 | 1984-02-02 | Toyo Sutoufuaa Chem:Kk | Production of catalyst component for alpha-olefin polymerization |
| US4525257A (en) * | 1982-12-27 | 1985-06-25 | Union Carbide Corporation | Low level irradiated linear low density ethylene/alpha-olefin copolymers and film extruded therefrom |
-
1982
- 1982-09-07 FR FR8215162A patent/FR2532649B1/en not_active Expired
-
1983
- 1983-08-22 AT AT83401691T patent/ATE17742T1/en not_active IP Right Cessation
- 1983-08-22 EP EP83401691A patent/EP0102895B2/en not_active Expired - Lifetime
- 1983-08-22 DE DE8383401691T patent/DE3362025D1/en not_active Expired
- 1983-08-29 AU AU18510/83A patent/AU563037B2/en not_active Ceased
- 1983-08-30 NZ NZ205423A patent/NZ205423A/en unknown
- 1983-09-05 NO NO833166A patent/NO162159C/en not_active IP Right Cessation
- 1983-09-06 PT PT77296A patent/PT77296B/en not_active IP Right Cessation
- 1983-09-06 FI FI833183A patent/FI75849C/en not_active IP Right Cessation
- 1983-09-06 CA CA000436128A patent/CA1212500A/en not_active Expired
- 1983-09-07 ES ES525448A patent/ES525448A0/en active Granted
- 1983-09-07 JP JP58164904A patent/JPS5964611A/en active Granted
-
1985
- 1985-01-03 US US06/689,017 patent/US4642328A/en not_active Expired - Lifetime
-
1987
- 1987-11-03 US US07/117,400 patent/US4987212A/en not_active Expired - Lifetime
-
1991
- 1991-12-23 CS CS914014A patent/CS401491A3/en unknown
Also Published As
| Publication number | Publication date |
|---|---|
| JPS5964611A (en) | 1984-04-12 |
| NO162159B (en) | 1989-08-07 |
| PT77296A (en) | 1983-10-01 |
| NO162159C (en) | 1989-11-15 |
| AU563037B2 (en) | 1987-06-25 |
| ES8405817A1 (en) | 1984-06-16 |
| NZ205423A (en) | 1986-09-10 |
| FR2532649B1 (en) | 1986-08-29 |
| DE3362025D1 (en) | 1986-03-13 |
| AU1851083A (en) | 1984-03-15 |
| NO833166L (en) | 1984-03-08 |
| PT77296B (en) | 1986-03-11 |
| FI833183A (en) | 1984-03-08 |
| EP0102895A2 (en) | 1984-03-14 |
| EP0102895A3 (en) | 1984-04-11 |
| ATE17742T1 (en) | 1986-02-15 |
| EP0102895B1 (en) | 1986-01-29 |
| JPH0553168B2 (en) | 1993-08-09 |
| FI75849C (en) | 1988-08-08 |
| US4987212A (en) | 1991-01-22 |
| FI833183A0 (en) | 1983-09-06 |
| US4642328A (en) | 1987-02-10 |
| ES525448A0 (en) | 1984-06-16 |
| CS401491A3 (en) | 1992-06-17 |
| EP0102895B2 (en) | 1995-07-05 |
| FR2532649A1 (en) | 1984-03-09 |
| FI75849B (en) | 1988-04-29 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| MKEX | Expiry |