JP6823802B2 - Method for producing ethylene polymerization catalyst and method for producing ethylene polymer - Google Patents

Description

The present invention relates to a method for producing an ethylene polymerization catalyst and a method for producing an ethylene polymer. More specifically, the present invention relates to a method for producing an ethylene polymerization catalyst for obtaining a highly active ethylene polymerization catalyst, and a method for producing an ethylene polymer using the ethylene polymerization catalyst. Regarding the manufacturing method.

Ethylene polymers and copolymers of ethylene and α-olefins containing ethylene as a main component (hereinafter, both polymers are referred to as ethylene-based polymers) are widely used as resin materials for various molded products. There is. Ethylene-based polymers have different required properties depending on the molding method and application. For example, a polymer having a relatively small molecular weight and a narrow molecular weight distribution is suitable for a product molded by an injection molding method, but a polymer having a relatively large molecular weight is suitable for a product molded by film molding or blow molding. , A polymer having a wide molecular weight distribution is suitable.
Conventionally, ethylene-based polymers having a wide molecular weight distribution have been supported on an inorganic oxide carrier such as silica with chromium trioxide or an arbitrary chromium compound that can be oxidized to chromium trioxide by firing in a non-reducing atmosphere. It is well known that it can be obtained by using a so-called Phillips catalyst, and many products are manufactured from polyethylene obtained from a Phillips catalyst.

Attempts have also been made to modify the Philips catalyst to improve catalytic performance. For example, a technique for improving the polymerization activity by coexisting a cyclic olefin monomer during olefin polymerization (Patent Document 1), and a technique for obtaining polyethylene having a well-balanced physical properties with a catalyst in which the surface of a Phillips catalyst is treated with a specific organoaluminum compound (Patent Document 1). Patent Document 2) discloses a technique (Patent Document 3) capable of expanding the molecular weight distribution of the obtained polymer by coexisting a phillips catalyst and a specific compound having a cyclopentadienyl ring.
On the other hand, a trivalent chromium catalyst that does not require calcination in a non-reducing atmosphere is also being developed. It is disclosed that an ethylene-based polymer having a wide molecular weight distribution and suitable for film molding and blow molding can be efficiently produced by a catalyst composed of a chromium amide compound, an inorganic oxide solid and alumoxane (Patent Document 4). In addition, the results of ethylene polymerization evaluation by activating a catalyst in which a chromium amide compound and an alkyl chromium compound are supported on silica with various almoxane are shown. (Non-Patent Document 1).
However, since a catalyst carrying a trivalent chromium compound is more expensive than a normal Philips catalyst, further improvement in catalytic activity is required.

JP-A-2007-302724 JP-A-2011-006589 Special table No. 2007-533822 International Publication No. 98/07762

Macromol. Chem. Phys. 2001, Volume 202, p1806-1811.

An object of the present invention is to provide a method for producing an ethylene polymerization catalyst capable of obtaining a highly active catalyst, and a method for producing an ethylene polymer using the same, in view of the above-mentioned problems of the prior art.

As a result of various studies to solve the above problems, the present inventors obtained a highly active ethylene polymerization catalyst by contacting an inorganic oxide carrier, an electron donating compound, and a compound containing a trivalent chromium atom. It was found that this was possible, and the present invention was completed.

That is, according to the first invention of the present invention, the inorganic oxide carrier (component A), the electron donating compound (component B), and the compound containing a trivalent chromium atom (component C) are brought into contact with each other. A method for producing an ethylene polymerization catalyst is provided.

According to the second invention, the ethylene polymerization catalyst according to the first invention, wherein the component B is a compound containing a Lewis basic substituent or a compound containing an unsaturated bond-containing hydrocarbon group. A manufacturing method is provided.

According to the third invention, the ethylene according to the second invention is characterized in that the compound containing a Lewis basic substituent is a compound having a substituent containing a phosphorus, nitrogen, oxygen or sulfur atom. A method for producing a polymerization catalyst is provided.

（１）
（式中、Ｘはフッ素、塩素、臭素、ヨウ素から選ばれる原子であり、Ｒ^１， Ｒ^２は水素または炭素数１〜１０の炭化水素基であり、Ｒ^３はヘテロ原子含有基を有いていてもよい芳香族炭化水素基である。） According to the fourth invention, the ethylene polymerization catalyst according to the second or third invention, wherein the compound containing a Lewis basic substituent is a silicon compound represented by the formula (1). A manufacturing method is provided.

(1)
(In the formula, X is an atom selected from fluorine, chlorine, bromine, and iodine, R ¹ and R ² are hydrogen or hydrocarbon groups having 1 to 10 carbon atoms, and R ³ has a hetero atom-containing group. It is an aromatic hydrocarbon group that may be used.)

（２）
（式中、Ｒ^４，Ｒ^５，Ｒ^６，Ｒ^７，Ｒ^８は、水素、炭素数１〜１０の炭化水素基、ケイ素含有基、窒素含有基、リン含有基、酸素含有基、または硫黄含有基である。） According to the fifth invention, in the silicon compound represented by the formula (1), wherein R ³ is a heteroatom aromatic optionally having a containing hydrocarbon group represented by the formula (2) The method for producing an ethylene polymerization catalyst according to a fourth invention is provided.

(2)
(In the formula, R ⁴ , R ⁵ , R ⁶ , R ⁷ , and R ⁸ are hydrogen, hydrocarbon groups having 1 to 10 carbon atoms, silicon-containing groups, nitrogen-containing groups, phosphorus-containing groups, oxygen-containing groups, or sulfur. It is a containing group.)

According to the sixth invention, the component C is a trivalent chromium compound having a substituted amino group or a trivalent chromium compound having an alkyl group optionally substituted with a substituted silyl group. The method for producing an ethylene polymerization catalyst according to any one of 1 to 5 is provided.

According to the seventh invention, there is provided the method for producing an ethylene polymerization catalyst according to the sixth invention, wherein the trivalent chromium compound having a substituted amino group is represented by the formula (3). ..

Cr [N (M ¹ R ⁹ R ¹⁰ R ¹¹ ) ₂ ] ₃ ... (3)

(In the formula, M ¹ is a carbon or silicon atom, respectively, and R ⁹ , R ¹⁰ , and R ¹¹ are hydrogen or hydrocarbon groups having 1 to 18 carbon atoms, respectively, which may be the same or different. .)

According to the eighth invention, the ethylene according to the sixth invention, wherein the trivalent chromium compound having an alkyl group optionally substituted with the substituted silyl group is represented by the formula (4). A method for producing a polymerization catalyst is provided.

Cr [CR ¹² (M ² R ¹³ R ¹⁴ R ¹⁵ ) (M ³ R ¹⁶ R ¹⁷ R ¹⁸ )] ₃
・ ・ ・ ・ ・ ・ (4)

(In the formula, M ² and M ³ are carbon or silicon atoms, respectively, and R ^{12 to} R ¹⁸ are hydrogen or hydrocarbon groups having 1 to 18 carbon atoms, respectively, which may be the same or different. .)

According to the ninth invention, the component A is selected from the group consisting of silica, alumina, titania, magnesia, zirconia, silica-alumina, silica-titania, silica-magnesia, silica-zirconia, and mixtures thereof. The method for producing an ethylene polymerization catalyst according to any one of the first to eighth inventions is provided.

According to the tenth invention, the inorganic oxide carrier (component A) is brought into contact with the electron donating compound (component B), and then the compound containing a trivalent chromium atom (component C) is brought into contact with each other. The method for producing an ethylene polymerization catalyst according to any one of the first to ninth inventions is provided.

According to the eleventh invention, a method for producing an ethylene polymer, which comprises polymerizing an olefin using an ethylene polymerization catalyst produced by the production method according to any one of the first to tenth inventions. Is provided.

A highly active catalyst can be obtained by producing a catalyst with a combination of a specific electron donating compound and a trivalent chromium compound.

Hereinafter, the method for producing an ethylene polymerization catalyst, which comprises contacting an inorganic oxide carrier (component A), an electron donating compound (component B), and a compound containing a trivalent chromium atom (component C), will be described for each item. Will be explained in detail.

1. 1. Inorganic oxide carrier (component A)
The inorganic oxide carrier of the present invention is not particularly limited as long as it is a carrier used as a carrier for olefin polymerization. For example, it is an oxide of a metal of Group 2, 4, 13 or 14 of the Periodic Table. More specifically, silica, alumina, titania, magnesia, zirconia, composite oxides thereof (for example, silica-alumina, silica-titania, silica-zirconia), aluminum phosphate and the like can be mentioned. These can be used alone or in combination of two or more. Of these, silica and silica-alumina are preferred.
The properties of the inorganic oxide support is not particularly limited, specific surface area of 50~1000m ² / g, preferably 200~800m ² / g, a pore volume of 0.5~3.0m ² / g, preferably Those having an average particle size of 0.7 to 2.5 m ² / g and an average particle size in the range of 1 to 200 μm, preferably 5 to 150 μm are preferably used. It is desirable that the inorganic oxide carrier be calcined at a specific temperature to remove the adsorbed water before use.
The calcination of the inorganic oxide carrier is usually carried out in a dry nitrogen gas stream under a molecular sieve flow in a temperature range of 100 to 500 ° C., preferably 150 to 450 ° C. for 30 minutes to 24 hours. It is preferable to supply a sufficient amount of nitrogen gas and dry the inorganic oxide carrier in a fluid state.

2. 2. Electron-donating compound (component B)
As the electron donating compound, any compound having an electron donating property can be used.
As the electron donating compound, a compound containing a Lewis basic substituent or a compound containing an unsaturated bond-containing hydrocarbon group is preferably exemplified. Examples of the compound containing a Lewis basic substituent include a compound having a substituent containing a phosphorus, nitrogen, oxygen or sulfur atom.

（１）
（式中、Ｘはフッ素、塩素、臭素、ヨウ素から選ばれる原子であり、Ｒ^１，Ｒ^２は水素または炭素数１〜１０の炭化水素基であり、Ｒ^３はヘテロ原子含有基を有いていてもよい芳香族炭化水素基である。） As the compound containing a Lewis basic substituent, a silicon compound represented by the following formula (1) can be preferably exemplified.

(1)
(Wherein, X is fluorine, chlorine, bromine, atom selected from iodine, R ^1, R ² is hydrogen or a hydrocarbon group having 1 to 10 carbon atoms, R ³ is have have a hetero atom-containing group It is an aromatic hydrocarbon group that may be used.)

The hydrocarbon group having 1 to 10 carbon atoms in R ¹ and R ² is not particularly limited, but is a methyl group, an ethyl group, an n-propyl group, an i-propyl group, an n-butyl group, an i-butyl group, and s. -Butyl group, t-butyl group, n-pentyl group, n-hexyl group, cyclopropyl group, cyclopentyl group, cyclohexyl group and other alkyl groups, phenyl group, trill group, dimethylphenyl group, ethylphenyl group, trimethylphenyl group Such as aryl groups are exemplified, and methyl group, ethyl group, n-propyl group, i-propyl group, n-butyl group, i-butyl group, s-butyl group, and t-butyl group are preferable. R ¹ and R ² may be the same or different.

The aromatic hydrocarbon group which may have a heteroatom-containing group is not particularly limited.
Examples of the aromatic hydrocarbon group include a phenyl group, a naphthyl group, an anthracenyl group, a biphenylyl group, an indenyl group, a fluorenyl group, a phenanthrenyl group, and the like, and these aromatic hydrocarbon groups have a heteroatom-containing group. May be good.

（２）
（式中、Ｒ^４，Ｒ^５，Ｒ^６，Ｒ^７，Ｒ^８は、水素、炭素数１〜１０の炭化水素基、ケイ素含有基、窒素含有基、リン含有基、酸素含有基、または硫黄含有基である。） In the silicon compound represented by the above formula (1), it is preferable that the above R ³ is an aromatic hydrocarbon group which may have a hetero atom-containing group represented by the following formula (2).

(2)
(In the formula, R ⁴ , R ⁵ , R ⁶ , R ⁷ , and R ⁸ are hydrogen, hydrocarbon groups having 1 to 10 carbon atoms, silicon-containing groups, nitrogen-containing groups, phosphorus-containing groups, oxygen-containing groups, or sulfur. It is a containing group.)

Here, the hydrocarbon group having 1 to 10 carbon atoms is not particularly limited, but is a methyl group, an ethyl group, an n-propyl group, an i-propyl group, an n-butyl group, an i-butyl group, and an s-butyl group. , T-butyl group, n-pentyl group, n-hexyl group, cyclopropyl group, cyclopentyl group, cyclohexyl group and other alkyl groups, phenyl group, trill group, dimethylphenyl group, ethylphenyl group, trimethylphenyl group and other aryl Group is exemplified.

The silicon-containing group is not particularly limited, but is a methylsilyl group, a dimethylsilyl group, a trimethylsilyl group, a triethylsilyl group, a butyldimethylsilyl group, a cyclohexyldimethylsilyl group, a dimethylphenylsilyl group, a triphenylsilyl group, or a diethyltrifluoromethylsilyl group. Examples thereof include a group, a chlorodimethylsilyl group, a bromodimethylsilyl group, a methoxydimethylsilyl group, a dimethoxymethylsilyl group, a trimethoxysilyl group, a methoxymethyldimethylsilyl group, and the like.

The nitrogen-containing group is not particularly limited, but is limited to an amino group, a dimethylamino group, a diethylamino group, a hydradino group, a pyrrolidino group, a methoxymethylamino group, a dimethoxyethylamino group, a trifluoromethylamino group, a cyano group, an isocyano group and an amidino group. Examples thereof include a group, an anilino group, a hydroxyamino group, an acetylamino group, and the like.

The phosphorus-containing group is not particularly limited, but includes a dimethylphosphino group, a diethylphosphino group, a diphenylphosphino group, a methylphenylphosphino group, a dimethoxyphosphino group, a diethoxyphosphino group, a dichlorophosphino group, and the like. Illustrated.

The oxygen-containing group is not particularly limited, and examples thereof include a hydroxyl group, a methoxy group, an ethoxy group, a butoxy group, a phenoxy group, a carboxyl group, an acetyl group, an acetoxy group, a formyl group, and a methoxycarbonyl group.

The sulfur-containing group is not particularly limited, and examples thereof include a mercapto group, a methylthio group, an ethylthio group, a phenylthio group, a thioformyl group, a thioacetyl group, a sulfino group, a sulfo group, a mesyl group, and a benzenesulfonyl group.

In the expression ^(2), R 4, is preferably one of at least one of R ⁸ is a heteroatom-containing group. As the heteroatom-containing group, a nitrogen-containing group, a phosphorus-containing group, and an oxygen-containing group are preferable, and a phosphorus-containing group is most preferable.
Specific compounds include ClSiMe ₂ Ph, ClSiEt ₂ Ph, ClSiPh ₃ , ClSiMeEtPh, ClSiMe ₂ Ph-2-SiMe ₃ , ClSiMe ₂ Ph-2-SiEt ₃ , ClSiMe ₂ Ph-2-SiMe ₂ tBu, ClSiMe ₂ Ph-2-NH ₂ , ClSiMe ₂ Ph-2-NMe ₂ , ClSiMe ₂ Ph-2-NPh ₂ , ClSiMe ₂ Ph-2-PH ₂ , ClSiMe ₂ Ph-2-PMe ₂ , ClSiMe ₂ Ph-2-PPh ₂ , ClSiMe ₂ Ph-2-OH, ClSiMe ₂ Ph-2-OMe, ClSiMe ₂ Ph-2-OPh, ClSiMe ₂ Ph-2-SH, ClSiMe ₂ Ph-2-SMe, ClSiMe2Ph-2-SPh, etc. Will be done. Among _{them, ClSiMe 2 Ph, ClSiMe 2 C} 6 H 4 -2-PPh 2, ClSiMe 2 C 6 H 4 -2-OH is preferred.

3.3 Compound containing trivalent chromium atom (component C)
The compound containing a trivalent chromium atom is not particularly limited, and a wide range of compounds containing a trivalent chromium atom can be used. For example, a trialkylchrome compound, a chromium carboxylate compound, a chromium-1,3-diketone compound, a chromic acid ester compound, and the like can be exemplified. In addition, cyclopentadienyl group-containing chromium compounds, for example, (C ₅ H ₅ ) Cr (CH ₃ ) ₂ , (C ₅ Me ₅ ) Cr (CH ₂ (SiMe ₃ ) ₂ ) ₂ , (C ₅ Me ₅ ) CrCH ₃ (CH ₂ (SiMe ₃ ) ₂ ) and the like can be mentioned.
As the compound containing a trivalent chromium atom, a trivalent chromium compound having a substituted amino group or a trivalent chromium compound having an alkyl group optionally substituted with a substituted silyl group is preferable.

The trivalent chromium compound having a substituted amino group is preferably a compound represented by the formula (3).

Cr [N (M ¹ R ⁹ R ¹⁰ R ¹¹ ) ₂ ] ₃ ... (3)

(In the formula, M ¹ is a carbon or silicon atom, respectively, and R ⁹ , R ¹⁰ , and R ¹¹ are hydrogen or hydrocarbon groups having 1 to 18 carbon atoms, respectively, which may be the same or different. .)

Here, the hydrocarbon groups having 1 to 18 carbon atoms in R ⁹ , R ¹⁰ and R ¹¹ include methyl group, ethyl group, n-propyl group, i-propyl group, n-butyl group and i-butyl group. Alkyl groups such as s-butyl group, t-butyl group, n-pentyl group, n-hexyl group, cyclopropyl group, cyclopentyl group, cyclohexyl group, phenyl group, trill group, dimethylphenyl group, ethylphenyl group, trimethylphenyl Examples thereof include an aryl group such as a group, a t-butylphenyl group, a di-t-butylphenyl group, a biphenylyl group, a 1-naphthyl group, a 2-naphthyl group, an acenaphthyl group, a phenanthryl group, and an anthryl group. Among these, methyl group, ethyl group, n-propyl group, i-propyl group, n-butyl group, i-butyl group, s-butyl group, t-butyl group, n-pentyl group, n-hexyl group. , Cyclopropyl group, cyclopentyl group, alkyl group such as cyclohexyl group, phenyl group are preferable, alkyl group is preferable, and methyl group is particularly preferable.

The trivalent chromium compound having an alkyl group which may be substituted with a substituted silyl group is preferably a compound represented by the formula (4).

Cr [CR ¹² (M ² R ¹³ R ¹⁴ R ¹⁵ ) (M ³ R ¹⁶ R ¹⁷ R ¹⁸ )] ₃
・ ・ ・ ・ ・ ・ (4)

(In the formula, M ² and M ³ are carbon or silicon atoms, respectively, and R ^{12 to} R ¹⁸ are hydrogen or hydrocarbon groups having 1 to 18 carbon atoms, respectively, which may be the same or different. .)

Here, the hydrocarbon groups having 1 to ¹⁸ carbon atoms in R ^{12 to} R ¹⁸ include methyl group, ethyl group, n-propyl group, i-propyl group, n-butyl group, i-butyl group and s-butyl. Group, t-butyl group, n-pentyl group, n-hexyl group, cyclopropyl group, cyclopentyl group, cyclohexyl group and other alkyl groups, phenyl group, trill group, dimethylphenyl group, ethylphenyl group, trimethylphenyl group, t Examples thereof include aryl groups such as −butylphenyl group, dit-butylphenyl group, biphenylyl group, 1-naphthyl group, 2-naphthyl group, acenaphthyl group, phenanthryl group and anthryl group.
Among these, methyl group, ethyl group, n-propyl group, i-propyl group, n-butyl group, i-butyl group, s-butyl group, t-butyl group, n-pentyl group, n-hexyl group. , Cyclopropyl group, cyclopentyl group, alkyl group such as cyclohexyl group, phenyl group are preferable, alkyl group is preferable, and methyl group is particularly preferable.
As the compound represented by the formula (4), Cr [CH (SiMe ₃ ) ₂ ] ₃ is preferably exemplified.

4. Production of Ethylene Polymerization Catalyst In the present invention, an inorganic oxide carrier (component A), an electron donating compound (component B), and a compound containing a trivalent chromium atom (component C) are brought into contact with each other.
When the electron donating compound (component B) is brought into contact with the inorganic oxide carrier (component A), the ratio of the two is not particularly limited. For example, the electron donating compound (component B) is preferably 0.01 to 20 mmol, more preferably 0.05 to 10 mmol, and further preferably 0.1 to 5 mmol with respect to 1 g of the inorganic oxide carrier (component A). ..
When the electron donating compound (component B) is brought into contact with the inorganic oxide carrier (component A), the electron donating compound (component) is dispersed in an organic solvent. It is preferable to add B). The organic solvent is not particularly limited, but THF, ether, hexane, heptane, toluene, acetone, and a mixed solvent thereof are preferably used. The reaction temperature is not particularly limited, and is preferably −78 ° C. to the boiling point of the solvent, more preferably −20 ° C. to 60 ° C. The reaction time is not particularly limited, but is preferably 1 minute to 48 hours, more preferably 10 minutes to 24 hours. After the reaction, it is separated by filtration to obtain a solid component. If necessary, the solid component may be washed with an organic solvent. An inorganic oxide carrier modified in this way is obtained. The modified inorganic oxide carrier may be dried by a method of removing the solvent under reduced pressure or the like.

When the compound (component C) containing a trivalent chromium atom is brought into contact with the inorganic oxide carrier (component A), the ratio of the two is not particularly limited. For example, the amount of the chromium atom supported by the compound (component C) containing a trivalent chromium atom is preferably 0.01 to 10 wt%, more preferably 0.03 to 0.03 to 1 g of the inorganic oxide carrier (component A). It is 5 wt%.
The reaction temperature is not particularly limited, and is preferably −78 ° C. to the boiling point of the solvent, more preferably −20 ° C. to 60 ° C. The reaction time is not particularly limited, but is preferably 1 minute to 24 hours, more preferably 10 minutes to 5 hours. After the loading reaction, a solid component (ethylene polymerization catalyst) having good fluidity can be obtained by a method of removing the solvent under reduced pressure or a method of separating by filtration. Alternatively, the olefin may be continuously polymerized without removing the solvent.

The component A, the component B and the component C can be contacted in any order, but it is preferable that the component A and the component B are contacted and then the component C is contacted.
If the component B and the component C are brought into contact with each other first, the component C may be decomposed. Further, when the component A and the component C are brought into contact with each other first, and then the component B is brought into contact with each other, there may be a component C that interacts with the component B and a component C that does not interact with the component B. This suggests that there may be a plurality of ethylene polymerization active species produced from the component C. From the viewpoint of the stability of the catalytic performance, it is preferable that the component A and the component B are brought into contact with each other, and then the component C is brought into contact with the component C.

5. Method for Producing Ethylene Polymer The method for producing an ethylene polymer of the present invention is characterized by polymerizing an olefin using the above-mentioned ethylene polymerization catalyst.
In carrying out the ethylene polymer of the present invention using the above-mentioned ethylene polymerization catalyst, a liquid phase polymerization method such as slurry polymerization or solution polymerization, or a gas phase polymerization method can be adopted. The liquid phase polymerization method is usually carried out in a hydrocarbon solvent. The hydrocarbon solvent is not particularly limited, and for example, a single or a mixture of inert hydrocarbons such as propane, butane, isobutane, hexane, heptane, cyclohexane, benzene, toluene, and xylene is used.
In the gas phase polymerization method, a commonly known polymerization method such as a fluidized bed or a stirring bed can be adopted in the coexistence of an inert gas, and in some cases, a so-called condensin mode in which a medium for removing heat of polymerization coexists can also be adopted. ..
The polymerization temperature in the liquid phase or vapor phase polymerization is generally 0 to 300 ° C., and practically 20 to 300 ° C. The catalyst concentration and ethylene pressure in the reactor may be any concentration and pressure as long as they are sufficient to allow the polymerization to proceed. Further, hydrogen or the like can coexist in the polymerization system for adjusting the molecular weight.

If impurities such as water are present in the polymerization system, the catalyst component is poisoned and the polymerization activity is not exhibited. Therefore, an organoaluminum compound may be used to prevent poisoning by the polar compound. The organoaluminum compound can be used alone or in combination of two or more.

Specific examples of the organic aluminum compound include trimethylaluminum, triethylaluminum, trinormalpropylaluminum, trinormalbutylaluminum, triisobutylaluminum, trinormalhexylaluminum, trinormaloctylaluminum, trinormaldecylaluminum, diethylaluminum chloride, diethylaluminum. Examples thereof include sesquichloride, diethylaluminum hydride, diethylaluminum ethoxide, diethylaluminum dimethylamide, diisobutylaluminum hydride, diisobutylaluminum chloride and the like. Of these, trialkylaluminum and alkylaluminum hydride are preferred. More preferably, it is trialkylaluminum in which R has 1 to 8 carbon atoms.

Further, if necessary, α-olefins such as propylene, 1-butene, 1-hexene, 4-methyl-1-pentene, and 1-octene are introduced into the reactor alone or in combination with ethylene. It can also be copolymerized.

Hereinafter, in order to explain the present invention more concretely and clearly, the present invention will be described in comparison with Examples and Comparative Examples, and the rationality and significance of the constituent requirements of the present invention and the excellence over the prior art will be demonstrated. To do.

1. 1. The raw material heptane used in Examples and Comparative Examples was dehydrated and deoxidized by the benzophenone ketyl method and then distilled under nitrogen. For THF and methanol, commercially available dehydrated products (Kanto Chemical Co., Ltd., Aldrich) were used as they were. Triethylamine (NEt ₃ ) was dehydrated with CaH ₂ and then distilled under nitrogen. As other general reagents, commercially available ones were used as they were. 1,3,5,7,9,11,14-Heptaisobutyltricyclo [7.3.3.15,11] hepataicone-endo-3,7,14-triol (( ⁱ Bu) ₇ Si ₇ O ₉ (OH) ₃ ) is commercially available The product (Aldrich) was used. For silica, ES70X grade (manufactured by PQ) was used. ClSiMe ₂ C ₆ H ₄ -2-PPh ₂ , an ortho-substituted arylchlorodimethylsilane compound, was synthesized according to Heteroatom Chem. 2012, Vol. 23, p520. Cr [CH (SiMe ₃ ) ₂ ] ₃ was synthesized according to Macromol. Chem. Phys. 2001, Vol. 202, p1806. As the trioctyl aluminum (TNOA), a commercially available hexane solution (Aldrich) was used.

2. 2. Example and Comparative Example 2.1 Example 1
2.1.1 Synthesis of ortho-substituted arylchlorodimethylsilane [Synthesis of ClSiMe ₂ C ₆ H ₄ -2-PPh ₂ ]
1.71 g (5.00 mmol) of (2-Bromophenyl) diphenylphosphine was added to 40 ml of toluene and 20 ml of ether, 3.4 ml (5.50 mmol) of 1.63 M n-BuLihexane solution was added dropwise, and the mixture was stirred at room temperature for 25 min. To the obtained reaction solution, 2.5 ml (1.50 mmol) of Me ₂ SiCl ₂ was added, and the mixture was stirred overnight at room temperature. After filtering the solution after the reaction, the obtained filtrate was dried under vacuum and reduced pressure to obtain 1.74 g (4.90 mmol, Yield 98%) of the target product.

2.1.2 Synthesis of ethylene polymerization catalyst (Cat-SiO _2- PPh ₂ ) Silica was calcined at 400 ° C. for 6 hours in a nitrogen atmosphere. 0.50 g of calcined silica was dispersed in 10 ml of THF, triethylamine (0.28 ml, 20 mmol) was added, and then a THF solution of ClSiMe ₂ C ₆ H ₄ -2-PPh ₂ (0.20 mmol) was added dropwise to room temperature. Stirred overnight underneath. The slurry solution was then filtered and washed 3 times each with THF, methanol and heptane. And dried under vacuum reduced pressure to give _{SiMe 2 C 6 H 4 -2-} PPh 2 group-modified silica (SiO ₂ -PPh _2). The obtained modified silica was dispersed in heptane (5.0 ml), and a heptane solution of Cr [CH (SiMe ₃ ) ₂ ] ₃ (51 mg, 0.096 mmol as Cr) was added so that the chromium carrying ratio was 1.0 wt%. In addition, it was heated at 40 ° C for 2 h. The slurry solution after the reaction was filtered, washed with heptane three times, and dried under vacuum and reduced pressure to obtain an ethylene polymerization catalyst (Cat-SiO _2- PPh ₂ ).

2.1.3 Ethylene polymerization
200 ml of heptane was added to a 1 L autoclave, the temperature was raised to each temperature, and then ethylene was saturated at a pressure of 0.50 MPa for 30 min. A hexane solution of trioctylaluminum (0.2 mmol-Al) and Cat-SiO _2- PPh ₂ (8 μmol-Cr) were introduced. During the polymerization, an ethylene pressure of 0.5 MPa and a polymerization temperature of 50 ° C. were maintained for 30 minutes. As a result, 8.44 g of polyethylene was obtained.

2.2 Example 2
In the polymerization of ethylene in Example 1, ethylene polymerization was carried out in the same operation using the same catalyst except that the polymerization temperature was set to 30 ° C. As a result, 4.58 g of polyethylene was obtained.

2.3 Comparative Example 1
2.3.1 Synthesis of ethylene polymerization catalyst (Cat-SiO ₂ ) Silica was calcined at 400 ° C. for 6 hours in a nitrogen atmosphere. 0.50 g of calcined silica was dispersed in heptane (5.0 ml), and a heptane solution of Cr [CH (SiMe ₃ ) ₂ ] ₃ (51 mg, 0.096 mmol as Cr) was added so that the chromium carrying ratio was 1.0 wt%. In addition, it was heated at 40 ° C for 2 h. After filtering the slurry solution after the reaction, it was washed with heptane three times and dried under vacuum and reduced pressure to obtain an ethylene polymerization catalyst (Cat-SiO ₂ ).
2.3.2 Ethylene polymerization In the ethylene polymerization of Example 1, ethylene polymerization was carried out in the same manner except that the catalyst (Cat-SiO ₂ ) synthesized in Comparative Example 1 was used as the ethylene polymerization catalyst. As a result, 7.39 g of polyethylene was obtained.

2.4 Comparative Example 2
In the ethylene polymerization of Example 2, ethylene polymerization was carried out in the same manner except that the catalyst (Cat-SiO ₂ ) synthesized in Comparative Example 1 was used as the ethylene polymerization catalyst. As a result, 4.08 g of polyethylene was obtained.

3. 3. Consideration of Experimental Results Both Example 1 and Comparative Example 1 have a polymerization temperature of 50 ° C. Comparing the two, the polymer yield of Example 1 was higher than that of Comparative Example 1. Therefore, it was confirmed that in Example 1, a catalyst having higher activity than in Comparative Example 1 was obtained.
Both Example 2 and Comparative Example 2 have a polymerization temperature of 30 ° C. Comparing the two, the polymer yield of Example 2 was higher than that of Comparative Example 2. Therefore, it was confirmed that in Example 2, a catalyst having higher activity than in Comparative Example 2 was obtained.

The present invention is not limited to the embodiments detailed above, and various modifications or modifications can be made within the scope of the claims of the present invention.

By producing a catalyst with a combination of a specific electron donating compound and a trivalent chromium compound, a highly active catalyst can be obtained, which is very useful for producing an ethylene polymer.

Claims (3)

The inorganic oxide carrier (component A) is reacted with the silicon compound (component B) represented by the formula (1), and then the trivalent chromium compound (component C) represented by the formula (4) is supported. A method for producing an ethylene polymerization catalyst.

(1)
(In the formula, X is an atom selected from fluorine, chlorine, bromine, and iodine, R ¹ and R ² are hydrogen or a hydrocarbon group having 1 to 10 carbon atoms, and R ³ is represented by the formula (2). )

(2)
(In the formula, R ⁴ , R ⁵ , R ⁶ , R ⁷ , and R ⁸ are hydrogen, hydrocarbon groups having 1 to 10 carbon atoms, silicon-containing groups, nitrogen-containing groups, phosphorus-containing groups, oxygen-containing groups, or sulfur. a-containing group, R ^4, at least one one nitrogen-containing group R ^8, a phosphorus-containing group, or an oxygen-containing group.)

Cr [CR ¹² (M ² R ¹³ R ¹⁴ R ¹⁵ ) (M ³ R ¹⁶ R ¹⁷ R ¹⁸ )] ₃
・ ・ ・ ・ ・ ・ (4)

(In the formula, M ² and M ³ are carbon or silicon atoms, respectively, and R ^{12 to} R ¹⁸ are hydrogen or hydrocarbon groups having 1 to 18 carbon atoms, respectively, which may be the same or different. .) The first aspect of claim 1 is that the component A is selected from the group consisting of silica, alumina, titania, magnesia, zirconia, silica-alumina, silica titania, silica-magnesia, silica-zirconia, and mixtures thereof. The method for producing an ethylene polymerization catalyst according to the above method. A method for producing an ethylene polymer, which comprises polymerizing an olefin using an ethylene polymerization catalyst produced by the production method according to claim 1 or 2 .