WO2016091872A1 - Procédé de production de polyéthylène haute densité - Google Patents

Procédé de production de polyéthylène haute densité Download PDF

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WO2016091872A1
WO2016091872A1 PCT/EP2015/078974 EP2015078974W WO2016091872A1 WO 2016091872 A1 WO2016091872 A1 WO 2016091872A1 EP 2015078974 W EP2015078974 W EP 2015078974W WO 2016091872 A1 WO2016091872 A1 WO 2016091872A1
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group
compound
density polyethylene
high density
astm
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PCT/EP2015/078974
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Nayef AL-ENAZI
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Sabic Global Technologies B.V.
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    • 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

Definitions

  • This invention relates to a process for the production of high density polyethylene, also referred to as HDPE, in particular to a process for the production of HDPE in a catalytic polymerization process using a heterogeneous catalyst system.
  • the polyolefin that is produced contains a fraction of catalyst material.
  • the catalyst is commonly not separated from the polymer product obtained from the process, it is therefore a requirement that the catalyst material is compatible with use in the target applications of the polymer.
  • HDPE may for example be used in injection moulding and blow-moulding processes for production of shaped objects.
  • shaped objects produced via injection moulding may for example be caps and closures for bottles and containers, boxes, crates, and/or tableware, for both food and non-food applications.
  • objects produced via blow moulding are containers or bottles for both food and non-food applications, said containers or bottles having for example internal volumes of up to 3 litres, alternatively up to 2 litres.
  • blow moulding processing there is an ongoing trend to reduce the production cycle time, in order to increase the productivity of the production lines, as well as to reduce energy consumption in the moulding process. This has resulted in so-called high-throughput blow moulding processes.
  • Such high-throughput blow moulding processes present certain requirements to HDPE in terms of processability.
  • Ziegler-Natta catalyst systems according to the state of the art is that they contain tetrahydrofuran.
  • Tetrahydrofuran is used as a solvent in the preparation of precursors for Ziegler-Natta catalysts that are prepared using TiC and MgC as ingredients.
  • Such catalysts contain a fraction of tetrahydrofuran.
  • chromium-based Phillips-type catalyst systems contain chromium. Chromium may be present in said Phillips-type catalysts in the form of chromium (II), chromium (III) and/or chromium (VI).
  • Chromium is known to have detrimental effects. Chromium compounds, in particular those containing chromium (VI), are suspected carcinogenic and mutagenic, and may cause health problems such as for example allergic reactions, skin rash, nose irritations and nose bleed, ulcers, weakened immune system, and damage to internal organs such as liver and kidney. Both tetrahydrofuran and chromium are undesirable to be present in polymer materials that are intended for use in food contact applications for health reasons. The use of tetrahydrofuran and chromium in the production process of high density polyethylene is also undesirable in view of workers health. This is for example presented in US Dept. of Labor report OSHA 3373-10 2009 'Hexavalent Chromium', which presents the hazards of workers exposed to chromium (VI), and in US Dept. of Labor OSHA report Occupational Health Guideline for Tetrahydrofuran', Feb.
  • VI chromium
  • a disadvantage of using metallocene catalyst systems is that the processability of HDPE grades in blow moulding processing is limited. In order to render metallocene HDPE grades suitable for application in high-throughput blow moulding processes, it is required to produce such grades in a multi-stage polymerization process.
  • HDPE materials essentially free from tetrahydrofuran and chromium by polymerization of ethylene and optionally other a-olefins in the presence of for example metallocene catalysts.
  • metallocene catalysts There are for example presented in US6181736.
  • such material suffer from drawbacks in that the processability is poor. This is caused by the narrow molecular weight distribution.
  • the object of the present invention to provide for a process for the production of HDPE in a gas-phase catalytic polymerization process using a heterogeneous catalyst system in which the catalyst system is essentially free of tetrahydrofuran and chromium, whilst resulting in a HDPE material having good processability properties for injection moulding and blow moulding processing such as for example molecular weight distribution and melt flow rate.
  • essentially free of tetrahydrofuran means that the catalyst system comprises for example at most 40 ppm of tetrahydrofuran, alternatively at most 20 ppm, alternatively at most 10 ppm, alternatively at most 5 ppm, alternatively at most 2 ppm.
  • essentially free of chromium means that the catalyst comprises for example at most 20 ppm of chromium or compounds comprising chromium atoms, alternatively at most 10 ppm, alternatively at most 5 ppm, alternatively at most 2 ppm.
  • step (b) contacting the product obtained in step (a) with modifying compounds (A), (B) and (C), wherein
  • compound (A) is at least one compound selected from the group consisting of carboxylic acid, carboxylic acid ester, ketone, acyl halide, aldehyde and alcohol;
  • R 11 f(R 12 0) g SiXh wherein f, g and h are each integers from 0 to 4 and the sum of f, g and h is equal to 4, Si is a silicon atom, O is an oxygen atom, X is a halide atom and R 11 and R 12 are the same or different and are independently selected from the group comprising an alkyl group, alkenyl group, alkadienyl group, aryl group, alkaryl group, alkenylaryl group and alkadienylaryl group;
  • R 13 0)4M wherein M is a titanium atom, a zirconium atom or a vanadium atom, O is an oxygen atom and R 13 is selected from the group comprising an alkyl group, alkenyl group, alkadienyl group, aryl group, alkaryl group, alkenylaryl group and alkadienylaryl group; and (c) contacting the product obtained in step (b) with a titanium halide compound having the general formula T1X4, wherein Ti is a titanium atom and X is a halide atom;
  • said Ziegler-Natta catalyst system is essentially free from tetrahydrofuran and chromium.
  • the high density polyethylene produced according to said process is essentially free from tetrahydrofuran and chromium.
  • the density of said high density polyethylene as measured according to ASTM D-792 13 is between 940 and 975 kg/m 3 .
  • said density of said high density polyethylene is between 945 and 975 kg/m 3 .
  • said density of said high density polyethylene is between 945 and 970 kg/m 3 .
  • the Ziegler-Natta systems catalyst of the present description comprise a transition metal- containing solid catalyst compound comprising a transition metal halide selected from titanium halide, an may optionally be supported on a metal or metalloid compound (e.g. a magnesium dichloride or silica).
  • a metal or metalloid compound e.g. a magnesium dichloride or silica.
  • the molar ratio of the titanium halide compound of step (c) to the magnesium compound of step (a) may for example be greater than 0.60.
  • the support for the Ziegler Natta catalyst may for example be selected from silica, alumina, magnesia, thoria, zirconia or mixtures thereof.
  • Compound (A) may for example be selected from methyl-n-propyl ketone, ethyl acetate, n- butyl acetate, acetic acid, isobutyric acid, isobutyraldehyde, ethanoyl chloride, ethanol and/or sec-butanol.
  • Compound (B) may for example be selected from tetraethoxysilane, n- propyltriethoxysilane, isobutyltrimethoxysilane, dimethyldichlorosilane, n-butyltrichlorosilane and/or silicon tetrachloride.
  • Compound (C) may for example be selected from titanium tetraethoxide, titanium tetra-n- butoxide and/or zirconium tetra-n-butoxide.
  • T1X4 may for example be TiCU-
  • the process may for example be a gas-phase process or a slurry process.
  • the high density polyethylene obtained according to the process of the present invention may for example have a melt index (Ml) measured according to ASTM D1238 13 at a temperature of 190°C and a load of 2.16 kg of higher than 1.0 g/ 0 min, alternatively higher than 2.0 g/10 min, alternatively higher than 4.0 g/10 min, alternatively higher than 5.0 g/10 min.
  • Ml melt index
  • the high density polyethylene obtained according to the process of the present invention may for example have a melt index (Ml) measured according to ASTM D1238 13 at a temperature of 190°C and a load of 2.16 kg of at most 50 g/10 min, alternatively at most 30 g/10 min, alternatively at most 20 g/10 min, alternatively at most 15 g/10 min.
  • Ml melt index
  • the high density polyethylene obtained according to the process of the present invention may for example have a high-load melt index (HLMI) measured according to ASTM D1238 13 at a temperature of 190°C and a load of 21.6 kg of higher than 20 g/10 min, alternatively higher than 22 g/10 min.
  • the high density polyethylene obtained according to the process of the present invention may for example have a high-load melt index (HLMI) measured according to ASTM D1238 13 at a temperature of 190°C and a load of 21.6 kg of at most 30 g/10 min, alternatively at most 28 g/10 min.
  • the high density polyethylene obtained according to the process of the present invention may for example have a melt flow rate (MFR) ranging between 1 and 10, alternatively between 1.5 and 5, alternatively between 2 and 4.
  • MFR melt flow rate
  • Said melt flow rate is defined as the ratio of the high-load melt index (HLMI) measured according to ASTM D1238 13 at a temperature of 190°C and a load of 21.6 kg, and the melt index (Ml) measured according to ASTM D1238 13 at a temperature of 190°C and a load of 21.6 kg.
  • the high density polyethylene obtained according to the process of the present invention may for example have a molecular weight distribution (MWD) as determined according to ASTM D-6474 12 ranging between 3.0 and 7.0, alternatively between 3.5 and 6.5, alternatively between 4.0 and 6.0. Said MWD is defined as the ratio between the weight average molecular weight Mw and the number average molecular weight Mn, as determined according to ASTM D- 6474 12.
  • MWD molecular weight distribution
  • An embodiment of the present invention relates to a high density polyethylene obtained by polymerizing ethylene and optionally other a-olefins in the presence of a Ziegler-Natta catalyst system, wherein said high density polyethylene has a density as measured according to ASTM D-792 13 ranging between 940 and 975 kg/m 3 , a molecular weight distribution (MWD) as determined according to ASTM D-6474 12 ranging between 3.0 and 7.0, and a melt flow rate (MFR) defined as the ratio of the high-load melt index (HLMI) measured according to ASTM D1238 13 at a temperature of 190°C and a load of 21.6 kg, and the melt index (Ml) measured according to ASTM D1238 13 at a temperature of 190°C and a load of 21 .6 kg ranging between 1 and 10, in which said Ziegler-Natta catalyst system is essentially free from tetrahydrofuran and chromium.
  • MFR melt flow rate
  • the high density polyethylene produced according to the present invention is used in an injection moulding process or a blow moulding process.
  • blow moulded article for food packaging produced using the high density polyethylene according to the present invention.
  • blow moulded articles may for example be selected from bottles or and/or containers
  • HDPE produced according to the present invention is suitable for application in high- throughput blow moulding processes.
  • said HDPE may be produced in a single-stage polymerization process. Production of Ziegler-Natta catalyst system
  • the Ziegler-Natta catalyst system as used in the present invention is produced in a process comprising a first step (a) of contacting a dehydrated support having hydroxyl
  • the support is any material containing hydroxyl groups. Suitable examples of such materials include inorganic oxides, such as silica, alumina, magnesia, thoria, zirconia and mixtures of such oxides. Preferably, porous silica is used as the support as higher bulk densities and higher catalyst productivities are obtained therewith.
  • Silica may be in the form of particles having a mean particle diameter of 1 micron to 500 microns, preferably from 5 microns to 150 microns and most preferably from 10 microns to 100 microns. Silica with a lower mean particle diameter produces a higher level of polymer fines and silica with a higher mean particle diameter reduces polymer bulk density.
  • the silica may have a surface area of 5 m 2 /g to 1500 m 2 /g, preferably from 50 m 2 /g to 1000 m 2 /g and a pore volume of from 0.1 cm 3 /g to 10.0 cm 3 /g, preferably from 0.3 cm 3 /g to 3.5 cm 3 /g, as higher catalyst productivity is obtained in this range.
  • the dehydrated solid support can be obtained by drying the solid support in order to remove physically bound water and to reduce the content of hydroxyl groups to a level which may be of from 0.1 mmol to 5.0 mmol hydroxyl groups per gram of support, preferably from 0.2 mmol to 2.0 mmol hydroxyl groups per gram of support, as this range allows sufficient incorporation of the active catalyst components to the support, determined by the method as described in J.J. Fripiat and J. Uytterhoeven, J. Phys. Chem. 66, 800, 1962 or by applying 1 H NMR spectroscopy.
  • the hydroxyl group content in this range may be achieved by heating and fluidizing the support at a temperature of from 150°C to 900°C for a time of 1 hour to 15 hours under a nitrogen or air flow.
  • the dehydrated support can be slurried, preferably by stirring, in a suitable hydrocarbon solvent in which the individual catalyst components are at least partially soluble.
  • suitable hydrocarbon solvents include n-pentane, isopentane,
  • cyclopentane n-hexane, isohexane, cyclohexane, n-heptane, isoheptane, n-octane, isooctane and n-decane.
  • the amount of solvent used is not critical, though the solvent should be used in an amount to provide good mixing of the catalyst components.
  • the magnesium compound is represented by the general formula MgR 1 R 2 , wherein R 1 and R 2 are the same or different and are independently selected from a group comprising an alkyl group, alkenyl group, alkadienyl group, aryl group, alkaryl group, alkenylaryl group and an alkadienylaryl group and may have from 1 to 20 carbon atoms.
  • Suitable examples of the magnesium compound include dimethylmagnesium, diethylmagnesium, ethylmethylmagnesium, di-n-propylmagnesium, diisopropylmagnesium, n-propylethylmagnesium,
  • the magnesium compound is selected from the group comprising di-n- butylmagnesium, n-butylethylmagnesium and n-octyl-n-butylmagnesium.
  • the magnesium compound can be used in an amount ranging from 0.01 to 10.0 mmol per gram of solid support, preferably from 0.1 to 3.5 mmol per gram of support and more preferably from 0.3 to 2.5 mmol per gram of support as by applying this range the level of polymer fines of the product is reduced and higher catalyst productivity is obtained.
  • the magnesium compound may be reacted, preferably by stirring, with the support at a temperature of 15°C to 140°C during 5 minutes to 150 minutes, preferably at a temperature of 20°C to 80°C for a duration of 10 minutes to 100 minutes.
  • the molar ratio of Mg to OH groups in the solid support can be in the range of 0.01 to 10.0, preferably of from 0.1 to 5.0 and more preferably of from 0.1 to 3.5, as the level of polymer fines of the product is reduced and higher catalyst productivity is obtained.
  • the modifying compound (A) is at least one compound selected from the group consisting of carboxylic acids, carboxylic acid esters, ketones, acyl halides, aldehydes and alcohols.
  • the modifying compound (A) may be represented by the general formula R 3 COOH, R 4 COOR 5 , R 6 COR 7 , R 8 COX, R 9 COH or R 10 OH, wherein X is a halide atom and R 3 , R 4 , R 5 , R 6 , R 7 , R 8 , R 9 and R 10 are independently selected from a group of compounds comprising an alkyl group, alkenyl group, alkadienyl group, aryl group, alkaryl group, alkenylaryl group and an alkadienylaryl group and may have from 1 to 20 carbon atoms.
  • carboxylic acids include acetic acid, propionic acid, isopropionic acid, butyric acid, isobutyric acid, valeric acid, isovaleric acid, caproic acid, isocaproic acid, enanthic acid, isoenanthic acid, caprylic acid, isocaprylic acid, pelargonic acid, isopelargonic acid, capric acid, isocapric acid, cyclopentanecarboxylic acid, benzoic acid and mixtures thereof.
  • carboxylic acid esters include methyl acetate, ethyl acetate, n- propyl acetate, isopropyl acetate, n-butyl acetate, isobutyl acetate, isoamyl acetate, ethyl butyrate, n-butyl butyrate and/or isobutyl butyrate.
  • ketones include dimethyl ketone, diethyl ketone, methyl ethyl ketone, di-n-propyl ketone, di-n-butyl ketone, methyl n-propyl ketone, methyl isobutyl ketone, cyclohexanone, methyl phenyl ketone, ethyl phenyl ketone, n-propyl phenyl ketone, n-butyl phenyl ketone, isobutyl phenyl ketone, diphenyl ketone and mixtures thereof.
  • acyl halides include ethanoyl chloride, propanoyl chloride, isopropanoyl chloride, n-butanoyl chloride, isobutanoyl chloride, benzoyl chloride and mixtures thereof.
  • aldehydes include acetaldehyde, propionaldehyde, n-butyraldehyde, isobutyraldehyde, n-pentanaldehyde, isopentanaldehyde, n-hexanaldehyde, isohexanaldehyde, n-heptanaldehyde, benzaldehyde and mixtures thereof.
  • Suitable examples of alcohols include methanol, ethanol, n-propanol, isopropanol, n- butanol, isobutanol, sec-butanol, tert-butanol, cyclobutanol, n-pentanol, isopentanol, cyclopentanol, n-hexanol, isohexanol, cyclohexanol, n-octanol, isooctanol, 2-ethylhexanol, phenol, cresol, ethylene glycol, propylene glycol and mixtures thereof.
  • the modifying compound (A) is at least one compound selected from the group comprising methyl n-propyl ketone, ethyl acetate, n-butyl acetate, acetic acid, isobutyric acid, isobutyraldehyde, ethanoyl chloride, ethanol and sec-butanol, and more preferably from methyl n-propyl ketone, n-butyl acetate, isobutyric acid and ethanoyl chloride as higher catalyst productivity and higher bulk density of the products are obtained and these compounds can be used to vary molecular weight distribution of the product.
  • the molar ratio of modifying compound (A) to magnesium in the solid support can be in a range of from 0.01 to 10.0, preferably of from 0.1 to 5.0, more preferably of from 0.1 to 3.5 and most preferably of from 0.3 to 2.5, as higher catalyst productivity and higher bulk density of the products are obtained.
  • the modifying compound (A) may be added to the reaction product obtained in step (a), preferably by stirring, at a temperature of 15°C to 140°C for a duration of 5 minutes to 150 minutes, preferably at a temperature of 20°C to 80°C for a duration of 10 minutes to 100 minutes.
  • the modifying compound (B) is a silicon compound represented by the general formula R 11 f(R 12 0) gSiXh , wherein f, g and h are each integers from 0 to 4 and the sum of a, b and c is equal to 4, Si is a silicon atom, O is an oxygen atom, X is a halide atom and R 11 and R 12 are the same or different, with a proviso that when c is equal to 4 then modifying compound (A) is not an alcohol.
  • R 11 and R 12 are independently selected from the group of compounds comprising an alkyl group, alkenyl group, alkadienyl group, aryl group, alkaryl group, alkenylaryl group and an alkadienylaryl group.
  • R 11 and R 12 may have from 1 to 20 carbon atoms.
  • Suitable silicon compounds include tetramethoxysilane, tetraethoxysilane, tetra-n- propoxysilane, tetraisopropoxysilane, tetra-n-butoxysilane, tetraisobutoxysilane, methyltrimethoxysilane, ethyltrimethoxysilane, n-propyltrimethoxysilane,
  • cyclohexylmethyldiethoxysilane phenylmethyldiethoxysilane, diphenyldiethoxysilane, trimethylethoxysilane, triethylethoxysilane, silicon tetrachloride, methyltrichlorosilane, ethyltrichlorosilane, n-propyltrichlorosilane, isopropyltrichlorosilane, n-butyltrichlorosilane, isobutyltnchlorosilane, n-pentyltrichlorosilane, n-hexyltrichlorosilane, n-octyltrichlorosilane, isooctyltrichlorosilane, vinyl Itrichlorosilane, phenyltrichlorosilane, dimethyldichlorosilane, diethyl dichlorosilane, isobutylmethyldich
  • diisobutyldichlorosilane isobutylisopropyldichlorosilane, dicyclopentyldichloro silane, cyclohexylmethyldichlorosilane, phenylmethyldichlorosilane, diphenyldichlorosilane, trimethylchlorosilane, triethylchlorosilane, chloro trimethoxysilane,
  • the modifying compound (B) used is selected from tetraethoxysilane, n-propyltriethoxysilane,
  • the molar ratio of modifying compound (B) to magnesium may be in a range of from 0.01 to 5.0, preferably from 0.01 to 3.0, more preferably from 0.01 to1 .0 and most preferably from 0.01 to 0.3, as higher catalyst productivity and higher bulk density are obtained.
  • the modifying compound (B) may be added to the reaction product obtained in step (a), preferably by stirring, at a temperature of 15°C to 140°C during 5 minutes to 150 minutes, preferably at a temperature of 20°C to 80°C during 10 minutes to 100 minutes.
  • the modifying compound (C) is a transition metal alkoxide represented by the general formula (R 13 0)4M, wherein M is a titanium atom, a zirconium atom or a vanadium atom, O is an oxygen atom and R 13 is a compound selected from the group of compounds comprising an alkyl group, alkenyl group, alkadienyl group, aryl group, alkaryl group, alkenylaryl group and an alkadienylaryl group. R 13 may have from 1 to 20 carbon atoms.
  • Suitable transition metal alkoxide compounds include titanium tetramethoxide, titanium tetraethoxide, titanium tetra-n-propoxide, titanium tetraisopropoxide, titanium tetra-n-butoxide, titanium tetraisobutoxide, titanium tetra-n-pentoxide, titanium tetraisopentoxide, titanium tetra-n- hexoxide, titanium tetra-n-heptoxide, titanium tetra-n-octoxide, titanium tetracyclohexoxide, titanium tetrabenzoxide, titanium tetraphenoxide, zirconium tetramethoxide, zirconium tetraethoxide, zirconium tetra-n-propoxide, zirconium tetraisopropoxide, zirconium tetra-n- butoxide, zirconium tetraisobutoxide
  • vanadium tetraisopropoxide vanadium tetra-n-butoxide, vanadium tetraisobutoxide, vanadium tetra-n- pentoxide, vanadium tetraisopentoxide, vanadium tetra-n-hexoxide, vanadium tetra-n-heptoxide, vanadium tetra-n-octoxide, vanadium tetracyclohexoxide, vanadium tetrabenzoxide, vanadium tetraphenoxide or mixtures thereof.
  • titanium tetraethoxide, titanium tetra-n-butoxide and zirconium tetra-n-butoxide are used because higher catalyst productivity and higher bulk density are obtained with the ability to vary the molecular weight distribution of the product by employing these preferred compounds.
  • the molar ratio of the modifying compound (C) to magnesium may be in the range of from 0.01 to 5.0, preferably from 0.01 to 3.0, more preferably from 0.01 to 1.0 and most preferably from 0.01 to 0.3, as higher catalyst productivity, higher bulk density and improved hydrogen response in polymerization are obtained.
  • the modifying compound (C) may be reacted, preferably by stirring, with the product obtained in step (a) at a temperature of 15°C to 140°C for a duration of 5 minutes to 150 minutes, preferably at a temperature of 20°C to 80°C for a duration of 10 minutes to 100 minutes.
  • the modifying compounds (A), (B) and (C) can be contacted in any order or simultaneously with the solid magnesium containing support obtained in step (a).
  • (A) is added first to the reaction product obtained in step (a) and then (B), followed by the addition of (C) as higher catalyst productivity and higher product bulk density are obtained by employing this order of adding the modifying compounds.
  • Pre- mixtures of the individual catalyst components can also be effectively utilized.
  • modifying compound (A) is methyl n-propyl ketone and modifying compound (C) is titanium tetraethoxide
  • modifying compound (B) is selected in the following order from the group consisting of isobutyltrimethoxysilane, n-propyltriethoxysilane, tetraethoxysilane, n- butyltrichlorosilane and silicon tetrachloride, at the same levels of titanium halide compound.
  • modifying compound (B) is silicon tetrachloride and modifying compound (C) is titanium tetraethoxide
  • modifying compound (A) is selected in the following order from the group consisting of isobutyraldehyde, ethyl acetate, n-butyl acetate, methyl n-propyl ketone and isobutyric acid, at the same levels of titanium halide compound.
  • the titanium halide compound is represented by the general formula T1X4, wherein Ti is a titanium atom and X is a halide atom.
  • Suitable titanium halide compounds include titanium tetrachloride, titanium tetrabromide, titanium tetrafluoride or mixtures thereof.
  • the preferred titanium halide compound is titanium tetrachloride, as higher catalyst productivity is obtained.
  • the molar ratio of the titanium halide compound to magnesium may be in the range of 0.01 to 10.0, preferably from 0.01 to 5.0 and more preferably from 0.05 to 1.0, as a better balance of high catalyst productivity and high bulk density is obtained.
  • the titanium halide compound may be added to the reaction mixture obtained by applying step (a) and step (b) in any conventional manner, such as by stirring, at a temperature of 15°C to 140°C for a duration of 5 minutes to 150 minutes, preferably at a temperature of 20°C to 80°C for a duration of 10 minutes to 100 minutes.
  • the reaction mixture may be then dried using a nitrogen purge and/or by vacuum at a temperature from 15°C to 140°C, preferably 30°C to 100°C and most preferably 50°C to 80°C to yield the Ziegler- Natta catalyst component.
  • the total molar ratio of the modifying compound (C) and the titanium halide compound to magnesium may be in the range of from 0.01 to 10.0, preferably of from 0.01 to 5.0 and more preferably of from 0.05 to 1.0, as a better balance of high catalyst productivity and high bulk density is obtained.
  • the total molar ratio of the modifying compound (C) and the titanium halide compound to hydroxyl (OH) groups in the support after dehydration may be in the range of from 0.01 to 10.0, preferably of from 0.01 to 5.0 and more preferably of from 0.05 to 1.0, as a better balance of high catalyst productivity and high bulk density is obtained. Higher levels would produce high catalyst productivity though with reduced bulk density, especially in a gas phase polymerization processes. Further, applying these amounts eliminates the requirement to conduct solvent decanting, solvent filtering, solvent washing steps in catalyst preparation and hence eliminates generation of highly hazardous solvent waste material.
  • the Ziegler-Natta catalyst system can comprise a catalyst component and a co-catalyst.
  • the co-catalyst is typically an organometallic compound such as aluminum alkyls, aluminum alkyl hydrides, lithium aluminum alkyls, zinc alkyls, calcium alkyls, magnesium alkyls or mixtures thereof.
  • Preferred co-catalysts are represented by the general formula R 12 n AIY 3 3-n, wherein Y 3 represents a halide atom; n represents an integer from 0 to 3; and R 12 is selected from a group of compounds comprising an alkyl group, alkenyl group, alkadienyl group, aryl group, alkaryl group, alkenylaryl group and alkadienylaryl group. R 12 may have from 1 to 20 carbon atoms.
  • cocatalyst examples include trimethylaluminium, triethylaluminum, tri-isobutylaluminum, tri-n-hexylaluminum, tri-n-octylaluminum, diethylaluminum chloride, diisobutylalumium chloride, ethylaluminium dichloride, isobutyl aluminum dichloride and mixtures thereof.
  • the cocatalyst is trimethylaluminium, triethylaluminum and/or tri- isobutylaluminum; and more preferably, the cocatalyst is triethylaluminum.
  • the cocatalyst may be used in a molar ratio of aluminium in the co-catalyst to titanium in the solid catalyst component of from 1 to 500, alternatively from 10 to 250, as high catalyst productivity is obtained.
  • the Ziegler-Natta catalyst system can be applied in gas phase processes to obtain HDPE. These processes have already been described in the prior art and are thus well-known to the skilled person.
  • ethylene copolymers and HDPE are produced by gas phase processes, such as stirred bed reactors and fluidized bed reactors or by slurry phase processes under polymerisation conditions already known in the art.
  • gas phase processes such as stirred bed reactors and fluidized bed reactors or by slurry phase processes under polymerisation conditions already known in the art.
  • gas phase processes are those disclosed for example in US 4302565 and US 4302566.
  • a suitable example is a gas phase fluidized bed polymerization reactor fed by a dry or slurry catalyst feeder.
  • the Ziegler-Natta catalyst may be introduced to the reactor in a site within the reaction zone to control the reactor production rate.
  • the reactive gases including ethylene and other alpha-olefins, hydrogen and nitrogen may be introduced to the reactor.
  • the produced polymer may be discharged from the reaction zone through a discharge system.
  • the bed of polymer particles in the reaction zone may be kept in fluidized state by a recycle stream that works as a fluidizing medium as well as to dissipate exothermal heat generated within the reaction zone.
  • the reaction and compression heats can be removed from the recycle stream in an external heat exchange system in order to control the reactor temperature.
  • Other means of heat removal from within the reactor can also be utilized, for example by the cooling resulting from vaporization of hydrocarbons such as isopentane, n-hexane or isohexane within the reactor.
  • hydrocarbons can be fed to the reactor as part of component reactant feeds and/or separately to the reactor to improve heat removal capacity from the reactor.
  • the gas composition in the reactor can be kept constant to yield a polymer with the required specifications by feeding the reactive gases, hydrogen and nitrogen to make-up the composition of the recycle stream.
  • Suitable operating conditions for the gas phase fluidized bed reactor typically include temperatures in the range for example of 50°C to 115°C, alternatively from 70°C to 110°C, an ethylene partial pressure from for example 3 bar to 15 bar, alternatively from 5 bar to 12 bar and a total reactor pressure for example from 10 bar to 40 bar, alternatively from 15 bar to 30 bar.
  • the superficial velocity of the gas, resulting from the flow rate of recycle stream within reactor may for example be from 0.2 m/s to 1.2 m/s, alternatively 0.2 m/s to 0.9 m/s.
  • HDPE can be produced.
  • Suitable examples of HDPE may include ethylene homopolymers or copolymers with a second a-olefin used as comonomer, said second a-olefin having from 3 to 20 carbon atoms.
  • the said second ⁇ -olefin may be selected from propylene, 1- butene, 1-pentene, 1-hexene, 1-octene, 4-methyl-1-pentene, 1 ,3-butadiene, 1 ,4- pentadiene, 1 ,5-hexadiene and mixtures thereof.
  • 1-butene, 1-hexene and 1- octene are used as second a-olefin, and most preferably 1-butene.
  • the amount of the comonomer needed depends generally on the desired product properties and specific comonomer used. The skilled person can easily select the required amount to obtain the desired product.
  • Ml melt index
  • the melt index of the polymers can be varied by controlling the polymerization temperature and the density of the polymer obtained.
  • a polymer density as measured according to ASTM D-792 13 in the range of 940 to 975 kg/m 3 , alternatively 945 kg/m 3 to 975 kg/m 3 , alternatively 945 kg/m 3 to 970 kg/m 3 can be obtained by using the Ziegler-Natta catalyst and by varying the comonomer to ethylene molar ratio; for instance, increasing the comonomer to ethylene molar ratio typically leads to a reduction in density.
  • the invention relates to a process for production of high density polyethylene in the presence of a Ziegler-Natta catalyst system, wherein the high density polyethylene is produced in a gas-phase polymerisation process, and wherein said Ziegler-Natta catalyst system is produced in a process comprising the steps of:
  • step (b) contacting the product obtained in step (a) with modifying compounds (A), (B) and (C), wherein
  • compound (A) is at least one compound selected from the group consisting of carboxylic acid, carboxylic acid ester, ketone, acyl halide, aldehyde and alcohol; • compound (B) is a compound having the general formula
  • R 11 f(R 12 0) g SiXh wherein f, g and h are each integers from 0 to 4 and the sum of f, g and h is equal to 4, Si is a silicon atom, O is an oxygen atom, X is a halide atom and R 11 and R 12 are the same or different and are independently selected from the group comprising an alkyl group, alkenyl group, alkadienyl group, aryl group, alkaryl group, alkenylaryl group and alkadienylaryl group;
  • R 13 0)4M wherein M is a titanium atom, a zirconium atom or a vanadium atom, O is an oxygen atom and R 13 is selected from the group comprising an alkyl group, alkenyl group, alkadienyl group, aryl group, alkaryl group, alkenylaryl group and alkadienylaryl group; and
  • step (c) contacting the product obtained in step (b) with a titanium halide compound having the general formula T1X4, wherein Ti is a titanium atom and X is a halide atom;
  • said Ziegler-Natta catalyst system is essentially free from tetrahydrofuran and chromium;
  • the density of said high density polyethylene as measured according to ASTM D-792 13 is in the range of 940 to 975 kg/m 3 ;
  • the molecular weight distribution (MWD) of the high density polyethylene as determined according to ASTM D-6474 12 is ranging between 3.0 and 7.0;
  • melt flow rate of the high density polyethylene defined as the ratio of the high-load melt index measured according to ASTM D1238 13 at a temperature of 190°C and a load of 21.6 kg, and the melt index measured according to
  • ASTM D1238 13 at a temperature of 190°C and a load of 21 .6 kg is between 1 and 10.
  • the catalyst as produced in step 1 was used to produce high density polyethylene in a fluidized bed gas phase polymerization reactor.
  • the fluidized bed gas phase polymerization reactor had an internal diameter of 45 cm and was operated with a 140 cm zone height.
  • the catalyst was fed to the reactor using a dry solid catalyst feeder to maintain a production rate of 12 kg per hour.
  • Ethylene, 1-butene, hydrogen and nitrogen were introduced to the reactor to yield polymer with the required specifications.
  • 5 wt% triethylaluminium (co-catalyst) solution in isopentane was continuously introduced to the reactor at a feed rate of 0.05 kg per hour.
  • the reactor bed temperature was maintained at 105°C, ethylene partial pressure at 10.3 bar, total reactor pressure at 20.7 bar and superficial gas velocity at 0.60 m/s.
  • the high density polyethylene product obtained was essentially free of tetrahydrofuran and chromium. Further process conditions are listed in table 1.
  • the material properties of the HDPE obtained from Example 1 were determined. The values are presented in table 2.
  • ASTM D-792 13 relates to a standard test method for density and specific gravity (relative density) of plastics by displacement.
  • ASTM D-1238 13 relates to a standard test method for melt flow rates of thermoplastics by extrusion plastometer.
  • ASTM D-6474 12 relates to a standard test method for determining molecular weight distribution and molecular weight averages of polyolefins by high temperature gel permeation chromatography.
  • ASTM D-5017 96 relates to a standard test method for determination of linear low density polyethylene (LLDPE) composition by carbon-13 nuclear magnetic resonance.
  • LLDPE linear low density polyethylene
  • ASTM D-6683 08 relates to a standard test method for measuring bulk density values of powders and other bulk solids as function of compressive stress.
  • ASTM D-1921 12 relates to a standard test method for particle size (sieve analysis) of plastic materials.
  • ASTM D-3418 08 relates to a standard test method for transition temperatures and enthalpies of fusion and crystallization of polymers by differential scanning calorimetry.
  • ASTM D-882 12 relates to a standard test method for tensile properties of thin plastic sheeting.
  • ASTM D-790 10 relates to standard test methods for flexural properties of unreinforced and reinforced plastics and electrical insulating materials.
  • ASTM D-256 10 relates to a standard test methods for determining the Izod pendulum impact resistance of plastics.
  • ASTM D-2240 05 relates to a standard test method for rubber property via durometer hardness.
  • ASTM D-1693 07 relates to a standard test method for environmental stress cracking of ethylene plastics
  • ASTM D-3123 09 relates to a standard test method for spiral flow of low-pressure thermosetting molding compounds
  • this HDPE which is produced in a single-stage polymerization process, shows material characteristics such as for example melt flow rate, molecular weight distribution, and crystallinity, that render the material suitable for injection moulding and blow moulding application, in particular for high-throughput blow moulding, whilst being essentially free from tetrahydrofuran and chromium .

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  • Chemical & Material Sciences (AREA)
  • Health & Medical Sciences (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Medicinal Chemistry (AREA)
  • Polymers & Plastics (AREA)
  • Organic Chemistry (AREA)
  • Transition And Organic Metals Composition Catalysts For Addition Polymerization (AREA)

Abstract

La présente invention concerne un procédé de production de polyéthylène haute densité en présence d'un système catalyseur Ziegler-Natta, ledit système de catalyseur Ziegler-Natta étant sensiblement exempt de tétrahydrofuranne et de chrome, ce qui donne des matériaux à base de polyéthylène haute densité appropriés pour le traitement par l'intermédiaire, par exemple, d'un moulage par injection ou d'un moulage par soufflage dans des produits d'emballage d'aliments par exemple.
PCT/EP2015/078974 2014-12-12 2015-12-08 Procédé de production de polyéthylène haute densité WO2016091872A1 (fr)

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Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20180355076A1 (en) * 2015-11-23 2018-12-13 Sabic Global Technologies B.V. High density polyethylene for the production of pipes
CN110214159A (zh) * 2017-01-24 2019-09-06 Sabic环球技术有限责任公司 具有纹理的聚合物组合物
WO2022112389A1 (fr) * 2020-11-27 2022-06-02 Sabic Global Technologies B.V. Procédé de préparation d'un support solide pour un procatalyseur de polymérisation d'oléfines

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0244678A1 (fr) * 1986-04-28 1987-11-11 Sumitomo Chemical Company, Limited Procédé de préparation de polymères d'alpha-oléfines
EP0855409A1 (fr) * 1997-01-28 1998-07-29 Fina Technology, Inc. Catalyseurs Ziegler-Natta améliorés pour la polymérisation d'oléfines
US5962615A (en) * 1994-03-02 1999-10-05 Mitsui Chemicals, Inc. Ethylene polymer
US20090203856A1 (en) * 2008-02-07 2009-08-13 Fina Technology, Inc. Ziegler-Natta catalyst
WO2012069157A1 (fr) * 2010-11-26 2012-05-31 Saudi Basic Industries Corporation (Sabic) Procédé de fabrication d'un composant de type catalyseur solide pour la polymérisation et la copolymérisation de l'éthylène

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0244678A1 (fr) * 1986-04-28 1987-11-11 Sumitomo Chemical Company, Limited Procédé de préparation de polymères d'alpha-oléfines
US5962615A (en) * 1994-03-02 1999-10-05 Mitsui Chemicals, Inc. Ethylene polymer
EP0855409A1 (fr) * 1997-01-28 1998-07-29 Fina Technology, Inc. Catalyseurs Ziegler-Natta améliorés pour la polymérisation d'oléfines
US20090203856A1 (en) * 2008-02-07 2009-08-13 Fina Technology, Inc. Ziegler-Natta catalyst
WO2012069157A1 (fr) * 2010-11-26 2012-05-31 Saudi Basic Industries Corporation (Sabic) Procédé de fabrication d'un composant de type catalyseur solide pour la polymérisation et la copolymérisation de l'éthylène

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20180355076A1 (en) * 2015-11-23 2018-12-13 Sabic Global Technologies B.V. High density polyethylene for the production of pipes
US10954320B2 (en) * 2015-11-23 2021-03-23 Sabic Global Technologies B.V. High density polyethylene for the production of pipes
CN110214159A (zh) * 2017-01-24 2019-09-06 Sabic环球技术有限责任公司 具有纹理的聚合物组合物
WO2022112389A1 (fr) * 2020-11-27 2022-06-02 Sabic Global Technologies B.V. Procédé de préparation d'un support solide pour un procatalyseur de polymérisation d'oléfines

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