JIANG YONG (CN)
GUO QI (CN)
JIANG YONG (CN)
| WO2003000747A1 | 2003-01-03 |
| GB2101609A | 1983-01-19 | |||
| US20040242409A1 | 2004-12-02 | |||
| EP0083456A1 | 1983-07-13 |
DATABASE CA [online] CHEMICAL ABSTRACTS SERVICE, COLUMBUS, OHIO, US; GUO, QI ET AL GUO, QI ET AL: "Preparation of catalyst for homopolymerization and copolymerization of ethylene Preparation of catalyst for homopolymerization and copolymerization of ethylene", XP002539941, retrieved from STN Database accession no. 2008:1021846
Claims
1. A method for preparing a titanium catalyst component, comprising the steps of:
a) reacting a magnesium dihalide, an electron donor solvent and a titanium halide,
b) reacting an alkyl borate ester with the reaction mixture obtained in step a) ,
c) adding inorganic oxide particles to the reaction mixture obtained in step b) ,
d) spray drying the suspension obtained in step c) .
2. The method according to claim 1, wherein the magnesium dihalide is selected from the group consisting of MgCl 2 , MgBr 2 and MgI 2 .
3. The method according to claim 1 or 2, wherein the electron donor solvent is selected from the group consisting of C 1 -C 4 alcohols, C 2 -C 6 fatty ethers and C 3 -C 4 cyclic ethers.
4. The method according to claim 3, wherein the electron donor solvent is selected from the group consisting of methanol, ethanol, n-propanol, isopropanol, butanol, isobutanol, ethylethers, hexylethers, tetrahydrofuran and mixtures thereof.
5. The method according to claim 4, wherein the electron donor solvent is tetrahydrofuran .
6. The method according to any one of claims 1 to 5, wherein the titanium halide is selected from the group consisting of TiCl 3 , TiCl 4 , TiBr 3 and TiBr 4 .
7. The method according to any one of claims 1 to 6, wherein the alkyl borate ester has the general formula
R is a Ci-Cio alkyl group, X is halogen, and
1 < n < 3.
8. The method according to claim 7, wherein the alkyl borate ester is selected from the group consisting of trimethylborate, triethylborate, tripropylborate, tributylborate, dichloromethoxyborane, chlorodiethoxyborane and dichloroethoxyborane .
9. The method according to any one of claims 1 to 8, wherein the inorganic oxide particles are selected from the group consisting of particles of SiO 2 , Al 2 O 3 and mixtures thereof.
10. The method according to claim 9, wherein in step c) the inorganic oxide particles are added in an amount such that the obtained suspension contains 10 wt . % to 60 wt . % of the inorganic oxide particles.
11. The method according to claim 9 or 10, wherein the inorganic oxide particles have a particle size of 0.01 μm to 10 μm.
12. The method according to claim 11, wherein the inorganic oxide particles are SiO 2 particles having a particle size of 0.01 μm to 1 μm.
13. The method according to any one of claims 1 to 12, wherein the magnesium dihalide, the titanium halide and the alkyl borate ester are provided in amounts such that 1 < Mg/Ti < 20 (mol/mol) and 0 < OR/Ti < 5 (mol/mol) , and wherein the electron donor solvent is provided in an amount of 3 to 500 mol based on one mol of Ti.
14. A titanium catalyst component, obtainable by the method of any one of claims 1 to 13.
15. The titanium catalyst component according to claim 14, wherein the average particle diameter of the titanium catalyst component is 5 μm to 45 μm.
16. A method for preparing a titanium catalyst, comprising:
reacting a titanium catalyst component according to claim 14 or 15 with an organic aluminum compound having the general formula
AlR' n X 3 -n wherein R' is hydrogen or a Ci-C 2 O alkyl group, X is F, Cl, Br or I, and 1 < n < 3
in a hydrocarbon solvent.
17. The method according to claim 16, wherein the organic aluminum compound is selected from the group consisting of AlEt 3 , AlEt 2 Cl, Al (isobutyl) 3, AMn-C 6 Hi 3 J 3 , Al (n-C 8 Hi 7 ) 3 and mixtures thereof.
18. The method according to claim 16 or 17, wherein the hydrocarbon solvent is selected from the group consisting of isopentane, hexane, heptane, toluene, xylene, naphtha, mineral oil and mixtures thereof.
19. A titanium catalyst, obtainable by the method of any one of claims 16 to 18.
20. The catalyst according to claim 19, wherein the molar ratio of Al in the organic aluminum compound and Ti in the titanium catalyst compound is in a range of 10 to 1000.
21. Use of a catalyst according to claim 19 or 20 for ethylene polymerization and copolymerization . |
Method for preparing a titanium catalyst component, titanium catalyst component, method for preparing a titanium catalyst and titanium catalyst
Technical field
The present invention relates to a method for preparing a titanium catalyst component, a titanium catalyst component, a method for preparing a titanium catalyst and a titanium catalyst .
The titanium catalyst on the basis of the titanium catalyst component according to the present invention is used for ethylene polymerization and copolymerization, in particular ethylene gas-phase polymerization using a fluidized bed in a condensation state or a super-condensation state, and can provide high catalytic activity to produce a polymer with a low amount of hexane-extractable components, a narrow particle size distribution and an improved particle morphology.
Background of the invention
For use in the Unipol gas-phase fluidized bed process, which is the most typical gas-phase polymerization process of ethylene, the catalyst is usually prepared by providing silica gel having a large particle size with active components (Ti and Mg) . Because the shape of the catalyst completely depends on the particle
shape of the silica gel carrier, catalyst performance also depends on the particle size and the microporous structure of silica gel used to prepare the catalyst.
For example, according to the catalyst for gas-phase polymerization by a fluidized bed process disclosed in US 4,302,565, the average particle size of the silica gel used is generally 40 μm to 80 μm. An LLDPE film-type resin made by this catalyst can provide excellent processing and mechanical properties. In the commercial gas-phase fluidized bed device, ethylene polymerization activity of this catalyst is generally about 3500 g PE/g cat.
However, the activity will significantly lower due to a reduction of the residence time of the catalyst, in case it is used for the condensation technology of the gas-phase fluidized bed, which consequently increases the ash content of the obtained ethylene polymer, which affects its performance . Thus, improving the catalytic activity of this kind of catalyst is one of the critical factors for enhancing the quality of an ethylene polymer produced by such a catalyst. In addition, the form and particle size distribution of polymer particles are the major factors of affecting the stable operation of a gas-phase fluidized bed device. Thus, excellent polymer particle morphology, particle size distribution and a lower content of fine powders is the target for this kind of catalyst.
With respect to the catalyst carrier disclosed in US 4,302,565, it is difficult to control a uniform distribution of the active components on the catalyst carrier, because the active components of the catalyst are loaded on the catalyst carrier
by the impregnation method, which results in difficulties in reproducing the preparation procedure of the catalyst. Thus, catalyst activity, particle morphology and particle size distribution of the obtained polymer are not satisfactory.
On the basis of the above active components of the catalyst, fumed SiC> 2 is used as the filler and mixed with a mixture obtained by reacting a titanium compound, a magnesium compound and electron donor compound according to US 4, 376, 062 and CN 1, 493, 599 A. The catalyst can be obtained by a spray drying method. For applying the catalyst in a gas-phase fluidized bed polymerization process of ethylene, the particle size and morphology of the obtained catalyst can be easily controlled, while the catalyst efficiency is also improved to some extent. However, the catalytic activity of the catalyst and the shape of the polymerization product are still unsatisfactory. Moreover, when this catalyst is applied in the copolymerization of ethylene and higher-level α-olefins (such as 1-hexene) , the content of hexane extracts is still high in the obtained polymer, which will reduce final product performance of a PE (Polyethylene) (co)polymer resin.
The purpose of the present invention is to overcome the above disadvantages of the technical methods in the art and to provide a catalyst for ethylene polymerization and copolymerization, in particular ethylene gas-phase polymerization using a fluidized bed in a condensation state or a super-condensation state, with high catalytic activity, which enables to reduce the hexane extracts in the obtained ethylene (co) polymer and to significantly improve the particle morphology and particle size distribution of the obtained PE (co)polymer.
In order to achieve the above purpose, the present invention provides according to one aspect a method for preparing a titanium catalyst component, comprising the steps of:
a) reacting a magnesium dihalide, an electron donor solvent and a titanium halide,
b) reacting an alkyl borate ester with the reaction mixture obtained in step a) ,
c) adding inorganic oxide particles to the reaction mixture obtained in step b) ,
d) spray drying the suspension obtained in step c) .
According to a preferred embodiment of the method for preparing a titanium catalyst component, the magnesium dihalide is selected from the group consisting of MgCl 2 , MgBr≥ and MgI 2 .
According to a further preferred embodiment of the method for preparing a titanium catalyst component, the electron donor solvent is selected from the group consisting of Ci-C 4 alcohols, C ∑ -Cβ fatty ethers and C3-C 4 cyclic ethers.
According to a further preferred embodiment of the method for preparing a titanium catalyst component, the electron donor solvent is selected from the group consisting of methanol, ethanol, n-propanol, isopropanol, butanol, isobutanol, ethylethers, hexylethers, tetrahydrofuran and mixtures thereof, wherein tetrahydrofuran is most preferred.
According to a further preferred embodiment of the method for preparing a titanium catalyst component, the titanium halide is selected from the group consisting of TiCl 3 , TiCl 4 , TiBr 3 and TiBr 4 .
According to a further preferred embodiment of the method for preparing a titanium catalyst component, the alkyl borate ester has the general formula
B(0R) n X 3 -n wherein
R is a Cχ-Cio alkyl group, X is halogen, and 1 < n < 3.
According to a further preferred embodiment of the method for preparing a titanium catalyst component, the alkyl borate ester is selected from the group consisting of trimethylborate, triethylborate, tripropylborate, tributylborate, dichloromethoxyborane, chlorodiethoxyborane and dichloroethoxyborane .
According to a further preferred embodiment of the method for preparing a titanium catalyst component, the inorganic oxide particles are selected from the group consisting of particles of SiC>2, Al 2 O 3 and mixtures thereof.
According to a further preferred embodiment of the method for preparing a titanium catalyst component, the inorganic oxide particles are added in an amount in step c) such that the obtained
suspension contains 10 wt.% to 60 wt.%, preferably 20 wt . % to 40 wt.% of the inorganic oxide particles.
According to a further preferred embodiment of the method for preparing a titanium catalyst component, the inorganic oxide particles have a particle size of 0.01 μm to 10 μm, preferably of 0.01 μm to 1 μm.
According to a further preferred embodiment of the method for preparing a titanium catalyst component, the inorganic oxide particles are Siθ 2 particles having a particle size of 0.01 μm to 1 μm.
Before using the inorganic carrier in the method for preparing a titanium catalyst component according to the present invention, it is preferred to subject the inorganic carrier to a baking dehydration treatment or to activate the inorganic carrier by an alkylation with usual alkylating agents like butyllithium, methyllithium etc.
The spray drying in the method for preparing a titanium catalyst component according to the present invention can be carried out by a conventional method using suitable conditions well known to the skilled person.
According to a further preferred embodiment of the method for preparing a titanium catalyst component, the magnesium dihalide, the titanium halide and the alkyl borate ester are provided in amounts such that 1 < Mg/Ti < 20 (mol/mol) and 0 < OR/Ti < 5 (mol/mol), preferably OR/Ti = 0.1 to 1.0 (mol/mol), and wherein
the electron donor solvent is provided in an amount of 3 to 500 mol, preferably 10 to 100 mol, based on one mol of Ti.
According to a further aspect, the present invention provides a titanium catalyst component, obtainable by the method for preparing a titanium catalyst component according to the present invention.
According to a preferred embodiment of the titanium catalyst component, the average particle diameter of the titanium catalyst component is 5 μm to 45 μm.
In case the present titanium catalyst component is used as a basis for a corresponding titanium catalyst, it can provide high catalytic activity to produce a polymer with a high bulk density, narrow particle size distribution and very fine particles in case the titanium catalyst is used for ethylene polymerization and copolymerization, in particular for ethylene gas-phase polymerization using a fluidized bed in a condensation state or a super-condensation state.
In order to be used for ethylene polymerization and copolymerization the titanium catalyst component according to the present invention must be activated, which means that it must be treated with sufficient activator compound to transform the Ti atom in the titanium catalyst component to an active state, such that a titanium catalyst is obtained.
Therefore, according to a further aspect the present invention provides a method for preparing a titanium catalyst, comprising the steps of:
reacting a titanium catalyst component according to the present invention with an organic aluminum compound having the general formula
AlR'nX 3 -n wherein
R 1 is hydrogen or a C 1 -C20 alkyl group, X is F, Cl, Br or I, and 1 < n < 3
in a hydrocarbon solvent.
According to a preferred embodiment of the method for preparing a titanium catalyst, the organic aluminum compound is selected from the group consisting of AlEt 3 , AlEt 2 Cl, Al (isobutyl) 3 , Al (n-C 6 Hi 3 ) 3 , Al (n-CβHi 7 ) 3 and mixtures thereof.
According to a further preferred embodiment of the method for preparing a titanium catalyst, the hydrocarbon solvent is selected from the group consisting of isopentane, hexane, heptane, toluene, xylene, naphtha, mineral oil and mixtures thereof.
In another aspect the present invention provides a titanium catalyst, obtainable by the method for preparing a titanium catalyst according to the present invention.
According to a preferred embodiment of the titanium catalyst, the molar ratio of Al in the organic aluminum compound and Ti in the titanium catalyst compound is in a range of 10 to 1000.
Before the actual polymerization, a pre-polymerization can be
carried out with said titanium catalyst component and ethylene or an α-olefin. This pre-polymerization can be conducted at a low temperature in the presence of a hydrocarbon solvent (such as hexane) , the above titanium catalyst component, said organic aluminum compound (such as triethyl aluminum) and ethylene or an α-olefin at an appropriate pressure.
In another aspect the present invention provides the use of a catalyst according to the present invention for ethylene polymerization and copolymerization.
The catalyst according to the present invention can be used for homopolymerization of ethylene or copolymerization of ethylene with other α-olefins, like for example propylene, 1-butene, 1-pentene, 1-hexene, 1-octene and 4-methyl-l-pentene . A gas-phase method, a slurry method and a solution may be used in the polymerization process, wherein a condensate or super-condensate operation technology of the gas-phase fluidized bed process is preferred.
To ensure a high polymerization rate, the polymerization using a titanium catalyst according to the present invention should be conducted at a suitable temperature. Generally, the polymerization temperature is 20 0 C to 200 0 C, preferably 60 0 C to 95 0 C. During the polymerization process, the pressure of the monomer is preferably 1 atm to 100 atm, more preferably 2 atm to 50 atm.
The following Examples are given to illustrate the present invention and are not intended to limit its scope.
Example 1
1. Preparation of a titanium catalyst
A 250 ml three-neck flask, wherein the air has been replaced by N 2 , is charged with 2.Og TiCl 3 - 1/3 AlCl 3 , 4.61 g MgCl 2 and 115 ml tetrahydrofuran. The contents of the flask are heated to 65 0 C under agitation and reacted for 2 h at 65 0 C. B(OEt) 3 is added in a molar ratio of Tiralkoxy group =1:0.2 and reacted at 65 0 C for 2 h. After that the obtained reaction mixture is cooled to 30 °C. A 250 ml three-neck flask, wherein the air has been replaced by N 2 , is charged with 6.9 g silica gel (TS-610, particle size = 0.02 μm to 0.1 μm, supplied by Cabot Corporation, MA, USA), the above cooled reaction mixture is added to the flask and the temperature is maintained at 30 0 C for 2 h under agitation. The stirred mixture is then spray dried with a spray dryer under the following conditions: inlet temperature = 160 0 C, outlet temperature = 80 0 C. The solid titanium catalyst component obtained after spray drying had a content of Ti, Mg and THF of 2.12 %, 6.08 % and 30.9 %, respectively. Mineral oil is added to the titanium catalyst component, such that a mineral oil solution with a solid content of 30 % is obtained. AlEt 2 Cl is added to the mineral oil solution and reacted with the titanium catalyst component for 20 min, whereupon Al(CeHi 3 J 3 is added. AlEt 2 Cl and Al(CeHi 3 J 3 are added such that the molar ratio of THF= AlEt 2 Cl : Al (C 6 H 13 ) 3 is 1:0.5:0.2.
2. Slurry polymerization of ethylene
A 2 1 reaction vessel is heated to 80 °C and the air in the vessel is replaced by dry N 2 and H 2 is blown into the vessel. The vessel is then simultaneously charged with 1 1 hexane, 1 mmol triethyl
aluminum, and 50 mg of the above prepared titanium catalyst. The contents of the vessel are heated to 75 0 C and H 2 is fed into the vessel such that the pressure in the vessel reaches 0.18 MPa. Then ethylene is fed into the vessel such that the total pressure in the vessel reaches 1.03 MPa (gauge pressure) and a polymerization is carried out for 2 h at 80 0 C. The results of the polymerization are shown in Table 1.
3. Gas-phase copolymerization of ethylene and 1-butene
The gas-phase copolymerization of ethylene and 1-butene is carried out in an ethylene gas-phase polymerization apparatus with a gas-phase fluidized bed having a diameter of 150 mm. The apparatus is charged with 300 g PE base material and then H 2 , ethylene, 1-butene and N 2 in a ratio of H 2 = 11.0 %, C 2 H 4 = 56.8 %, 1-butene = 22.2 % and N 2 = 10.0 % as well as 15 mmol triethylaluminum are fed into the apparatus, the apparatus is heated to 85 0 C and 160 mg of the above prepared titanium catalyst are added to start the polymerization. The polymerization time is 4 h and the total pressure of the circulating gas having the above-indicated composition is 1.73 MPa. The polymerization results are shown in table 2.
Example 2
1. Preparation of a titanium catalyst
A 250 ml three-neck flask, wherein the air has been replaced by N 2 , is charged with 2.O g TiCl 3 • 1/3 AlCl 3 , 4.6 g MgCl 2 and 115 ml tetrahydrofuran . The contents of the flask are heated to 65 0 C under agitation and reacted for 2 h at 65 0 C. B(OEt) 3 is added
in a molar ratio of Tiialkoxy group =1:0.4 and reacted at 65 °C for 2 h. After that the obtained reaction mixture is cooled to 30 0 C. A 250 ml three-neck flask, wherein the air has been replaced by N 2 , is charged with 6.9 g silica gel (TS-610, particle size = 0.02 μm to 0.1 μm, supplied by Cabot Corporation, MA, USA), the above cooled reaction mixture is added to the flask and the temperature is maintained at 30 0 C for 2 h under agitation. The stirred mixture is then spray dried with a spray dryer under the following conditions: inlet temperature = 160 0 C, outlet temperature = 80 °C. The solid titanium catalyst component obtained after spray drying had a content of Ti, Mg and THF of 2.24 %, 6.25 % and 29 %, respectively. Mineral oil is added to the titanium catalyst component, such that a mineral oil solution with a solid content of 30 % is obtained. AlEt 2 Cl is added to the mineral oil solution and reacted with the titanium catalyst component for 20 min, whereupon Al (C 6 Hi 3 ) 3 is added. AlEt 2 Cl and Al(C 6 Hχ 3 ) 3 are added such that the molar ratio of THF:AlEt 2 Cl:Al (C 6 Hi 3 ) 3 is 1:0.5:0.2.
2. Slurry polymerization of ethylene
A 2 1 reaction vessel is heated to 80 0 C and the air in the vessel is replaced by dry N 2 and H 2 is blown into the vessel. The vessel is then simultaneously charged with 1 1 hexane, 1 mmol triethyl aluminum, and 50 mg of the above prepared titanium catalyst. The contents of the vessel are heated to 75 0 C and H 2 is fed into the vessel such that the pressure in the vessel reaches 0.18 MPa. Then ethylene is fed into the vessel such that the total pressure in the vessel reaches 1.03 MPa (gauge pressure) and a polymerization is carried out for 2 h at 80°C. The results of the polymerization are shown in Table 1.
3. Gas-phase copolymerization of ethylene and 1-butene
The gas-phase copolymerization of ethylene and 1-butene is carried out in an ethylene gas-phase polymerization apparatus with a gas-phase fluidized bed having a diameter of 150 mm. The apparatus is charged with 350 g PE base material and then H 2 , ethylene, 1-butene and N 2 in a ratio of H 2 = 11.0 %, C 2 H 4 = 56.8 %, 1-butene = 22.2 % and N 2 = 10.0 % as well as 15 mmol triethylaluminum are fed into the apparatus, the apparatus is heated to 85 0 C and 150 mg of the above prepared titanium catalyst are added to start the polymerization. The polymerization time is 4 h and the total pressure of the circulating gas having the above-indicated composition is 1.7 MPa. The polymerization results are shown in table 2.
Example 3
1. Preparation of a titanium catalyst
A 250 ml three-neck flask, wherein the air has been replaced by N 2 , is charged with 2.O g TiCl 3 • 1/3 AlCl 3 , 4.6 g MgCl 2 and 115 ml tetrahydrofuran. The contents of the flask are heated to 65 0 C under agitation and reacted for 2 h at 65 0 C. B(OEt) 3 is added in a molar ratio of Ti:alkoxy group =1:0.6 and reacted at 65 0 C for 2 h. After that the obtained reaction mixture is cooled to 30 0 C. A 250 ml three-neck flask, wherein the air has been replaced by N 2 , is charged with 6.9 g silica gel (TS-610, particle size = 0.02 μm to 0.1 μm, supplied by Cabot Corporation, MA, USA), the above cooled reaction mixture is added to the flask and the temperature is maintained at 30 0 C for 2 h under agitation. The stirred mixture is then spray dried with a spray dryer under the following conditions: inlet temperature = 160 0 C, outlet
temperature = 80 0 C. The solid titanium catalyst component obtained after spray drying had a content of Ti, Mg and THF of 2.49 %, 6.12 % and 30 %, respectively. Mineral oil is added to the titanium catalyst component, such that a mineral oil solution with a solid content of 30 % is obtained. AlEt 2 Cl is added to the mineral oil solution and reacted with the titanium catalyst component for 20 min, whereupon Al (C 6 Hi 3 ) 3 is added. AlEt 2 Cl and Al(CeHi 3 ) 3 are added such that the molar ratio of THFiAlEt 2 Cl: Al (C 6 Hi 3 J 3 is 1:0.5:0.2.
2. Slurry polymerization of ethylene
A 2 1 reaction vessel is heated to 80 0 C and the air in the vessel is replaced by dry N 2 and H 2 is blown into the vessel. The vessel is then simultaneously charged with 1 1 hexane, 1 mmol triethyl aluminum, and 50 mg of the above prepared titanium catalyst. The contents of the vessel are heated to 75 0 C and H 2 is fed into the vessel such that the pressure in the vessel reaches 0.18 MPa. Then ethylene is fed into the vessel such that the total pressure in the vessel reaches 1.03 MPa (gauge pressure) and a polymerization is carried out for 2 h at 80 0 C. The results of the polymerization are shown in Table 1.
3. Gas-phase copolymerization of ethylene and 1-butene
The gas-phase copolymerization of ethylene and 1-butene is carried out in an ethylene gas-phase polymerization apparatus with a gas-phase fluidized bed having a diameter of 150 mm. The apparatus is charged with 350 g PE base material and then H 2 , ethylene, 1-butene and N 2 in a ratio of H 2 = 11.0 %, C 2 H 4 = 56.8 %, 1-butene = 22.2 % and N 2 = 10.0 % as well as 15 mmol
triethylaluminum are fed into the apparatus, the apparatus is heated to 85 0 C and 150 mg of the above prepared titanium catalyst are added to start the polymerization. The polymerization time is 4 h and the total pressure of the circulating gas having the above-indicated composition is 1.7 MPa. The polymerization results are shown in table 2.
Example 4
1. Preparation of a titanium catalyst
A 250 ml three-neck flask, wherein the air has been replaced by N 2 , is charged with 2.O g TiCl 3 • 1/3 AlCl 3 , 4.6 g MgCl 2 and 115 ml tetrahydrofuran. The contents of the flask are heated to 65 0 C under agitation and reacted for 2 h at 65 0 C. B(OEt) 3 is added in a molar ratio of Ti:alkoxy group =1:1 and reacted at 65 °C for 2 h. After that the obtained reaction mixture is cooled to 30 0 C. A 250 ml three-neck flask, wherein the air has been replaced by N 2 , is charged with 6.9 g silica gel (TS-610, particle size = 0.02 μm to 0.1 μm, supplied by Cabot Corporation, MA, USA), the above cooled reaction mixture is added to the flask and the temperature is maintained at 30 °C for 2 h under agitation. The stirred mixture is then spray dried with a spray dryer under the following conditions: inlet temperature = 160 0 C, outlet temperature = 80 0 C. The solid titanium catalyst component obtained after spray drying had a content of Ti, Mg and THF of 2.26 %, 5.99 % and 31.8 %, respectively. Mineral oil is added to the titanium catalyst component, such that a mineral oil solution with a solid content of 30 % is obtained. AlEt 2 Cl is added to the mineral oil solution and reacted with the titanium catalyst component for 20 min, whereupon Al(CeHi 3 J 3 is added.
AlEt 2 Cl and Al (C 6 Hi 3 ) 3 are added such that the molar ratio of THFiAlEt 2 Cl :Al(C 6 Hi 3 ) 3 is 1:0.5:0.2.
2. Slurry polymerization of ethylene
A 2 1 reaction vessel is heated to 80 0 C and the air in the vessel is replaced by dry N 2 and H 2 is blown into the vessel. The vessel is then simultaneously charged with 1 1 hexane, 1 mmol triethyl aluminum, and 50 mg of the above prepared titanium catalyst. The contents of the vessel are heated to 75 0 C and H 2 is fed into the vessel such that the pressure in the vessel reaches 0.18 MPa. Then ethylene is fed into the vessel such that the total pressure in the vessel reaches 1.03 MPa (gauge pressure) and a polymerization is carried out for 2 h at 80 0 C. The results of the polymerization are shown in Table 1.
3. Gas -phase copolymerization of ethylene and 1-butene
The gas-phase copolymerization of ethylene and 1-butene is carried out in an ethylene gas-phase polymerization apparatus with a gas-phase fluidized bed having a diameter of 150 mm. The apparatus is charged with 350 g PE base material and then H 2 , ethylene, 1-butene and N 2 in a ratio of H 2 = 11.0 %, C 2 H 4 = 56.8 %, 1-butene = 22.2 % and N 2 = 10.0 % as well as 15 mmol triethylaluminum are fed into the apparatus, the apparatus is heated to 85 0 C and 150 mg of the above prepared titanium catalyst are added to start the polymerization. The polymerization time is 4 h and the total pressure of the circulating gas having the above-indicated composition is 1.7 MPa. The polymerization results are shown in table 2.
Example 5
1. Preparation of a titanium catalyst
A 250 ml three-neck flask, wherein the air has been replaced by N 2 , is charged with 2.O g TiCl 3 • 1/3 AlCl 3 , 4.6 g MgCl 2 and 115 ml tetrahydrofuran . The contents of the flask are heated to 65 0 C under agitation and reacted for 2 h at 65 °C. B(OEt) 3 is added in a molar ratio of Ti:alkoxy group =1:1.5 and reacted at 65 0 C for 2 h. After that the obtained reaction mixture is cooled to 30 0 C. A 250 ml three-neck flask, wherein the air has been replaced by N 2 , is charged with 6.9 g silica gel (TS-610, particle size = 0.02 μm to 0.1 μm, supplied by Cabot Corporation, MA, USA), the above cooled reaction mixture is added to the flask and the temperature is maintained at 30 0 C for 2 h under agitation. The stirred mixture is then spray dried with a spray dryer under the following conditions: inlet temperature = 160 0 C, outlet temperature = 80 0 C. The solid titanium catalyst component obtained after spray drying had a content of Ti, Mg and THF of 2.33 %, 6.01 % and 30,9 %, respectively. Mineral oil is added to the titanium catalyst component, such that a mineral oil solution with a solid content of 30 % is obtained. AlEt 2 Cl is added to the mineral oil solution and reacted with the titanium catalyst component for 20 min, whereupon Al(CeHi 3 J 3 is added. AlEt 2 Cl and Al (CeHi 3 ) 3 are added such that the molar ratio of THF:AlEt 2 Cl:Al (C 6 Hi 3 J 3 is 1:0.5:0.2.
2. Slurry polymerization of ethylene
A 2 1 reaction vessel is heated to 80 0 C and the air in the vessel is replaced by dry N 2 and H 2 is blown into the vessel. The vessel is then simultaneously charged with 1 1 hexane, 1 mmol triethyl
aluminum, and 50 mg of the above prepared titanium catalyst. The contents of the vessel are heated to 75 °C and H2 is fed into the vessel such that the pressure in the vessel reaches 0.18 MPa. Then ethylene is fed into the vessel such that the total pressure in the vessel reaches 1.03 MPa (gauge pressure) and a polymerization is carried out for 2 h at 8O 0 C. The results of the polymerization are shown in Table 1.
3. Gas-phase copolymerization of ethylene and 1-butene
The gas-phase copolymerization of ethylene and 1-butene is carried out in an ethylene gas-phase polymerization apparatus with a gas-phase fluidized bed having a diameter of 150 mm. The apparatus is charged with 350 g PE base material and then H 2 , ethylene, 1-butene and N 2 in a ratio of H 2 = 11.0 %, C 2 H 4 = 56.8 %, 1-butene = 22.2 % and N 2 = 10.0 % as well as 15 mmol triethylaluminum are fed into the apparatus, the apparatus is heated to 85 C C and 150 mg of the above prepared titanium catalyst are added to start the polymerization. The polymerization time is 4 h and the total pressure of the circulating gas having the above-indicated composition is 1.7 MPa. The polymerization results are shown in table 2.
Comparative Example 1
1. Preparation of a titanium catalyst
A 250 ml three-neck flask, wherein the air has been replaced by N 2 , is charged with 2.O g TiCl 3 • 1/3 AlCl 3 , 4.6 g MgCl 2 and 115 ml tetrahydrofuran. The contents of the flask are heated to 65 0 C under agitation and reacted for 2 h at 65 0 C. After that the
obtained reaction mixture is cooled to 30 0 C. A 250 ml three-neck flask, wherein the air has been replaced by N 2 , is charged with 6.9 g silica gel (TS-610, particle size = 0.02 μm to 0.1 μm, supplied by Cabot Corporation, MA, USA) , the above cooled reaction mixture is added to the flask and the temperature is maintained at 30 0 C for 2 h under agitation. The stirred mixture is then spray dried with a spray dryer under the following conditions: inlet temperature = 160 0 C, outlet temperature = 8O 0 C. The solid titanium catalyst component obtained after spray drying had a content of Ti, Mg and THF of 2.41 %, 6.19 % and 33 %, respectively. Mineral oil is added to the titanium catalyst component, such that a mineral oil solution with a solid content of 30 % is obtained. AlEt 2 Cl is added to the mineral oil solution and reacted with the titanium catalyst component for 20 min, whereupon Al (CeHi 3 ) 3 is added. AlEt 2 Cl and Al (CeHi 3 ) 3 are added such that the molar ratio of THF: AlEt 2 Cl : Al (C 6 H 13 ) 3 is 1:0.5:0.2.
2. Slurry polymerization of ethylene
A 2 1 reaction vessel is heated to 80 0 C and the air in the vessel is replaced by dry N 2 and H 2 is blown into the vessel. The vessel is then simultaneously charged with 1 1 hexane, 1 mmol triethyl aluminum, and 50 mg of the above prepared titanium catalyst. The contents of the vessel are heated to 75 0 C and H 2 is fed into the vessel such that the pressure in the vessel reaches 0.18 MPa. Then ethylene is fed into the vessel such that the total pressure in the vessel reaches 1.03 MPa (gauge pressure) and a polymerization is carried out for 2 h at 80 0 C. The results of the polymerization are shown in Table 1.
3. Gas-phase copolymerization of ethylene and 1-butene
The gas-phase copolymerization of ethylene and 1-butene is carried out in an ethylene gas-phase polymerization apparatus with a gas-phase fluidized bed having a diameter of 150 mm. The apparatus is charged with 350 g PE base material and then H 2 , ethylene, 1-butene and N 2 in a ratio of H 2 = 11.0 %, C 2 H 4 = 56.8 %, 1-butene = 22.2 % and N 2 = 10.0 % as well as 15 mmol triethylaluminum are fed into the apparatus, the apparatus is heated to 85 0 C and 150 mg of the above prepared titanium catalyst are added to start the polymerization. The polymerization time is 4 h and the total pressure of the circulating gas having the above-indicated composition is 1.7 MPa. The polymerization results are shown in table 2.
Comparative Example 2
1. Preparation of a titanium catalyst
A 250 ml three-neck flask, wherein the air has been replaced by N 2 , is charged with 2.O g TiCl 3 • 1/3 AlCl 3 , 4.6 g MgCl 2 and 115 ml tetrahydrofuran. The contents of the flask are heated to 65 0 C under agitation and reacted for 2 h at 65 0 C. B(OEt) 3 is added in a molar ratio of Tiralkoxy group =1:0.3 and reacted at 65 0 C for 2 h. After that the obtained reaction mixture is cooled to 30 0 C. A 250 ml three-neck flask, wherein the air has been replaced by N 2 , is charged with 6.9 g silica gel (TS-610, particle size = 0.02 μm to 0.1 μm, supplied by Cabot Corporation, MA, USA), the above cooled reaction mixture is added to the flask and the temperature is maintained at 30 C C for 2 h under agitation. The stirred mixture is then spray dried with a spray dryer under the following conditions: inlet temperature = 160 0 C, outlet
temperature = 80 0 C. The solid titanium catalyst component obtained after spray drying had a content of Ti, Mg and THF of 2.28 %, 6.39 % and 33 %, respectively. Mineral oil is added to the titanium catalyst component, such that a mineral oil solution with a solid content of 30 % is obtained. AlEt 2 Cl is added to the mineral oil solution and reacted with the titanium catalyst component for 20 min, whereupon Al (C 6 H 13 ) 3 is added. AlEt 2 Cl and Al(C 6 Hi 3 ) 3 are added such that the molar ratio of THF:AlEt 2 Cl:Al (C 6 Hi 3 ) 3 is 1:0.5:0.2.
2. Slurry polymerization of ethylene
A 21 reaction vessel is heated to 80 0 C and the air in the vessel is replaced by dry N 2 and H 2 is blown into the vessel. The vessel is then simultaneously charged with 1 1 hexane, 1 mmol triethyl aluminum, and 50 mg of the above prepared titanium catalyst. The contents of the vessel are heated to 75 0 C and H 2 is fed into the vessel such that the pressure in the vessel reaches 0.18 MPa. Then ethylene is fed into the vessel such that the total pressure in the vessel reaches 1.03 MPa (gauge pressure) and a polymerization is carried out for 2 h at 80°C. The results of the polymerization are shown in Table 1.
3. Gas-phase copolymerization of ethylene and 1-butene
The gas-phase copolymerization of ethylene and 1-butene is carried out in an ethylene gas-phase polymerization apparatus with a gas-phase fluidized bed having a diameter of 150 mm. The apparatus is charged with 350 g PE base material and then H 2 , ethylene, 1-butene and N 2 in a ratio of H 2 = 11.0 %, C 2 H 4 = 56.8 %, 1-butene = 22.2 % and N 2 = 10.0 % as well as 15 mmol
triethylaluminum are fed into the apparatus, the apparatus is heated to 85 0 C and 150 mg of the above prepared titanium catalyst are added to start the polymerization. The polymerization time is 4 h and the total pressure of the circulating gas having the above-indicated composition is 1.7 MPa. The polymerization results are shown in table 2.
Table 1 Results of the ethylene/1-butene slurry polymerization
Comp. -Ex.: Comparative example
Table 2 Results of the ethylene/1-butene gas-phase fluidized bed polymerization
Ex. : Example
Comp. -Ex.: Comparative example
The experimental results show that the titanium catalyst according to the present invention prepared from the titanium catalyst component according to the present invention can provide a polyethylene having a high bulk density, a very narrow particle size distribution and a low amount of fine particles, which is particularly suitable for ethylene gas-phase polymerization using a fluidized bed, preferably in a condensation state or a super-condensation state.