Method for producing ethylene copolymer

Abstract

To provide a method for producing an ethylene copolymer that contains a quantity of structural units derived from olefin having 4 or more carbon atoms equal to or greater than conventional levels, and that is readily producible with high molecular weight, using an olefin polymerization catalyst that uses a solid titanium catalyst component.SOLUTION: Provided is a method for producing an ethylene copolymer by polymerizing ethylene with an olefin containing 4 to 20 carbon atoms in the presence of a catalyst component (I), which is obtained by contacting (A) a solid titanium catalyst component comprising magnesium, titanium, a halogen, and an electron donor (a), (B) an organometallic compound, and (C) a compound having two or more ether bonds present via a plurality of atoms, under conditions satisfying the following requirement (α): the molar ratio of the number of metal atoms contained in component (B) [B] to the number of moles of component (C) [C] ([B] / [C]) is 1 or more and 9.5 or less.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a method for producing an ethylene copolymer, which is a copolymer of an olefin containing ethylene. [Background technology]

[0002] Olefin polymers such as ethylene homopolymers and linear low-density ethylene polymers (LLDPE) are excellent in transparency, mechanical strength, etc., and are widely used as raw materials for applications such as packaging materials and containers, such as films and bottles. Various methods have been disclosed for producing such ethylene polymers, and it is known that ethylene polymers can be produced with high polymerization activity by using an olefin polymerization catalyst containing a solid titanium catalyst component containing titanium, magnesium, a halogen, and an optional electron donor (e.g., Patent Documents 1 and 2). The solid titanium catalyst component tends to have a significant effect on the stable operation and efficient production of the production process, and solid titanium catalyst components with excellent particle properties often contain a component such as an electron donor.

[0003] As mentioned above, olefin polymers are suitably used as container and packaging materials to replace glass, paper, etc. Meanwhile, in recent years, growing awareness of environmental issues has led to demands for further improvement in the durability of containers made from olefin polymers, and there is a demand for olefin polymers that exhibit high performance in environmental stress resistance tests and the like (e.g., Patent Document 3). In response to this trend, various standards such as PE100 and PE125 have been established. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 9-328514 [Patent Document 2] Japanese Patent Application Publication No. 3-294310 [Patent Document 3] Japanese Patent Application Laid-Open No. 2004-269864 Summary of the Invention [Problem to be solved by the invention]

[0005] Olefin polymers with excellent durability as described above often contain components with extremely high molecular weights. Appropriate toughness is also required. Suitable olefin polymers are considered to be those containing a high molecular weight ethylene copolymer that contains a relatively large amount of structural units derived from olefins having 4 or more carbon atoms. On the other hand, olefins having 4 or more carbon atoms tend to have a significantly slower polymerization rate than ethylene, although this depends on the type of olefin polymerization catalyst, and the influence of chain transfer reactions is relatively increased. For these reasons, it tends to be relatively difficult to efficiently produce such ethylene copolymers under commercial plant conditions.

[0006] Therefore, an object of the present invention is to provide a method for producing an ethylene copolymer, which uses an olefin polymerization catalyst that includes a solid titanium catalyst component, and which facilitates the production of an ethylene copolymer that contains structural units derived from olefins having 4 or more carbon atoms in an amount equal to or greater than that of conventional ethylene copolymers and has a high molecular weight. [Means for solving the problem]

[0007] As a result of investigations conducted by the present inventors to solve the above-mentioned problems, they found that a method of polymerizing olefins in the presence of a solid titanium catalyst containing specific components and an olefin polymerization catalyst containing an organoaluminum compound and a specific polyether compound is suitable, and thus completed the present invention.

[0008] One aspect of the present invention relates to the following items [1] to [6]. [1] (A) a solid titanium catalyst component containing magnesium, titanium, a halogen, and an electron donor (a); (B) an organometallic compound, and (C) A compound having two or more ether bonds present through multiple atoms, A catalyst component (I) obtained by contacting under conditions that satisfy the following (α): In the presence of A method for producing an ethylene copolymer, comprising polymerizing ethylene and an olefin containing an olefin having 4 to 20 carbon atoms. (α) The molar ratio ([B] / [C]) of the number of moles of metal atoms contained in the component (B) [B] to the number of moles of the component (C) [C] is 1 or more and 9.5 or less. (However, the electron donor (a) is a compound selected from a silicon-containing compound, an organic acid compound, an organic acid ester compound, a ketone compound, an aldehyde compound, a nitrogen-containing compound, and a phosphorus-containing compound.)

[0009] [2] The catalyst component (I) comprises the components (A), (B) and (C), The method for producing an ethylene copolymer according to [1], wherein the catalyst component is obtained by contacting under conditions that satisfy the following (β): (β) The molar ratio ([B] / [Ti]) of the number of moles of titanium atoms [Ti] contained in the component (A) to the number of moles of metal atoms [B] contained in the component (B) is 1 or more and 9.5 or less. [3] The method for producing an ethylene copolymer according to [1] or [2], wherein the component (C) is a compound having two or more ether bonds present via a plurality of carbon atoms.

[0010] [4] The method for producing an ethylene copolymer according to any one of [1] to [3], wherein the electron donor (a) is an organic acid ester compound.

[0011] [5] The method for producing an ethylene copolymer according to any one of [1] to [4], wherein the ethylene copolymer has a content of ethylene-derived structural units of 50 mol % or more. [6] The method for producing an ethylene copolymer according to any one of [2] to [5], wherein the [B] / [C] is 1.5 or more and 9 or less, and the [B] / [Ti] is 1.5 or more and 9 or less. [Effects of the Invention]

[0012] The above-mentioned method can provide a method for producing an ethylene copolymer that can produce a high-molecular-weight ethylene copolymer without impairing copolymerizability, as compared with conventional catalysts, and thus makes it possible to industrially produce ethylene copolymers having an appropriate branched structure and density over a wide molecular weight range. DETAILED DESCRIPTION OF THE INVENTION

[0013] The method for producing the ethylene copolymer according to the present invention will be described below. In the present invention, the term "polymerization" is sometimes used to mean not only homopolymerization but also copolymerization, and the term "polymer" is sometimes used to mean not only homopolymer but also copolymer. Furthermore, the term "ethylene copolymer" includes the meaning of a polymer containing structural units derived from ethylene and structural units derived from other monomers such as olefins. In the present disclosure, unless otherwise specified, the expressions "XX to YY" and "XX to YY" representing a numerical range mean a numerical range including the lower and upper limits, which are the endpoints. Furthermore, when a numerical range is described in stages, the upper and lower limits of each numerical range can be combined in any way. Furthermore, the various monomers in the present disclosure may be derived from fossil raw materials, biomass, or chemically recycled.

[0014] In the method for producing an ethylene copolymer of the present invention, olefins including ethylene and an olefin having 4 to 20 carbon atoms are polymerized in the presence of the following catalyst component (I). <Catalyst Component (I)> The catalyst component (I) according to the present invention is (A) a solid titanium catalyst component containing magnesium, titanium, a halogen, and an electron donor (a); (B) organometallic compounds, and (C) A compound having two or more ether bonds present through multiple atoms, It can be obtained by contacting under conditions that satisfy the following (α): (α) The molar ratio ([B] / [C]) of the number of moles of metal atoms contained in the (B) compound [B] to the number of moles of the (C) component [C] is 1 or more and 9.5 or less. (However, the electron donor (a) is a compound selected from a silicon-containing compound, an organic acid compound, an organic acid ester compound, a ketone compound, an aldehyde compound, a nitrogen-containing compound, and a phosphorus-containing compound.)

[0015] Solid titanium catalyst component (A) The solid titanium catalyst component (A) according to the present invention (hereinafter also referred to as component (A)) is a solid titanium catalyst component containing magnesium, titanium, a halogen, and an electron donor (a). The solid titanium catalyst component (A) can be selected from known solid titanium catalyst components. For example, it can be obtained by a method including a step of contacting a liquid magnesium compound, a liquid titanium compound, and an electron donor (a) by any method, or a method including a step of contacting a magnesium compound having excellent particle properties, which is prepared via a liquid magnesium compound state, with a liquid titanium compound and an electron donor (a) by any method. More specifically, in addition to Patent Document 2, preferred examples include solid titanium catalyst components containing electron donors disclosed in JP-A-56-811, JP-A-58-83006, and JP-A-57-63110.

[0016] The lower limit of the magnesium content in the solid titanium catalyst component (A) is preferably 11 mass%, more preferably 12 mass%, and even more preferably 13 mass%, while the upper limit is preferably 23 mass%, more preferably 22 mass%, and even more preferably 21 mass%. The lower limit of the titanium content in the solid titanium catalyst component (A) is preferably 3 mass%, more preferably 5 mass%, while the upper limit is preferably 11 mass%, more preferably 10 mass%, even more preferably 9 mass%.

[0017] (Electron donor (a)) The solid titanium catalyst component (A) used in the present invention contains an electron donor (a) which is a compound selected from a silicon-containing compound, an organic acid compound, an organic acid ester compound, a ketone compound, an aldehyde compound, a nitrogen-containing compound, and a phosphorus-containing compound. The preferred content of the electron donor (a) in the solid titanium catalyst component (A) is 2 to 30% by mass, and the lower limit value is preferably 4% by mass, more preferably 5% by mass. On the other hand, the preferred upper limit value is 25% by mass, more preferably 22% by mass, and even more preferably 20% by mass.

[0018] Examples of such a compound include, as the silicon-containing compound, (c) an organosilicon compound having no active hydrogen. The organosilicon compound having no active hydrogen (c) used as the electron donor (a) in the present invention is, for example, R 1 x R 2 y Si(OR 3 ) z (R 1 , R 2 are each independently a hydrocarbon group or a halogen, R 3 is a hydrocarbon group, and 0 ≦ x < 2, 0 ≦ y < 2, 0 < z ≦ 4. ).

[0019] Specific examples of organosilicon compounds represented by such formulas include tetramethoxysilane, tetraethoxysilane, tetrapropoxysilane, tetrabutoxysilane, tetrakis(2-ethylhexyloxy)silane, ethyltrimethoxysilane, ethyltriethoxysilane, vinyltrimethoxysilane, methyltrimethoxysilane, n-propyltriethoxysilane, decyltrimethoxysilane, cyclopentyltrimethoxysilane, 2-methylcyclopentyltrimethoxysilane, 2,3-dimethylcyclopentyltrimethoxysilane, cyclohexyltrimethoxysilane, 2-norbornanetrimethoxysilane, 2-norbornanemethyldimethoxysilane, phenyltrimethoxysilane, γ-chloropropyltrimethoxysilane, methyltriethoxysilane, ethyltriethoxysilane, vinyl ... Ethoxysilane, t-butyltriethoxysilane, n-butyltriethoxysilane, iso-butyltriethoxysilane, decyltriethoxysilane, cyclopentyltriethoxysilane, cyclohexyltriethoxysilane, 2-norbornanetriethoxysilane, phenyltriethoxysilane, γ-aminopropyltriethoxysilane, chlorotriethoxysilane, ethyltriisopropoxysilane, vinyltributoxysilane, trimethylphenoxysilane, methyltriallyloxy(allyoxy)silane, vinyltris(β-methoxyethoxysilane), vinyltriacetoxysilane, dimethyldimethoxysilane, diisopropyldimethoxysilane, t-butylmethyldimethoxysilane, dicyclopentyldimethoxysilane, bis(2-methylcyclopentyl)dimethoxysilane, bis(2,3-Dimethylcyclopentyl)dimethoxysilane, dicyclohexyldimethoxysilane, cyclohexylmethyldimethoxysilane, diphenyldimethoxysilane, phenylmethyldimethoxysilane, bis-o-tolyldimethoxysilane, bis-m-tolyldimethoxysilane, bis-p-tolyldimethoxysilane, bis-ethylphenyldimethoxysilane, dimethyldiethoxysilane, t-butylmethyldiethoxysilane, t-amylmethyldiethoxysilane, dicyclopentyldiethoxysilane, diphenyldiethoxysilane, bis-p-tolyldi Examples of suitable silanes include ethoxysilane, cyclohexylmethyldiethoxysilane, trimethylmethoxysilane, trimethylethoxysilane, tricyclopentylmethoxysilane, tricyclopentylethoxysilane, dicyclopentylmethylmethoxysilane, dicyclopentylethylmethoxysilane, hexenyltrimethoxysilane, cyclopentyldimethylmethoxysilane, cyclopentyldiethylmethoxysilane, dicyclopentylmethylethoxysilane, cyclopentyldimethylethoxysilane, and dimethyltetraethoxydisiloxane.

[0020] Among these, tetramethoxysilane, tetraethoxysilane, cyclohexylmethyldimethoxysilane, etc. are preferably used, with tetraethoxysilane being particularly preferred from the standpoint of catalytic activity. Other preferred carboxylic acids include carboxylic acids having 7 or more carbon atoms, such as caprylic acid, 2-ethylhexanoic acid, nonylic acid, and undecylenic acid.

[0021] Other examples include organic acid esters, organic acid halides, organic acid anhydrides, ketones, tertiary amines, phosphites, phosphates, carboxylic acid amides, nitriles, aliphatic carbonates, and pyridines. More specifically, examples include methyl formate, methyl acetate, ethyl acetate, vinyl acetate, propyl acetate, i-butyl acetate, t-butyl acetate, octyl acetate, cyclohexyl acetate, methyl chloroacetate, ethyl dichloroacetate, ethyl propionate, ethyl pyruvate, ethyl pivalate, methyl butyrate, ethyl valerate, methyl methacrylate, ethyl crotonate, ethyl cyclohexanecarboxylate, methyl benzoate, ethyl benzoate, propyl benzoate, butyl benzoate, octyl benzoate, cyclohexyl benzoate, propyl benzoate, butyl benzoate, octyl benzoate, cyclohexyl benzoate, methyl ... C2-18 organic acid esters such as phenyl, benzyl benzoate, methyl toluate, ethyl toluate, amyl toluate, ethyl ethylbenzoate, methyl anisate, ethyl anisate, ethyl ethoxybenzoate, etc.; C2-15 acid halides such as acetyl chloride, benzoyl chloride, toluoyl chloride, etc.; acid anhydrides such as acetic anhydride, phthalic anhydride, maleic anhydride, benzoic anhydride, trimellitic anhydride, tetrahydrophthalic anhydride, etc.; acetone, methyl ethyl ketone, methyl isobutyl ketone, etc. ketones having 3 to 20 carbon atoms such as acetophenone, ethyl n-butyl ketone, acetophenone, benzophenone, benzoquinone, and cyclohexanone; tertiary amines such as trimethylamine, triethylamine, tributylamine, tribenzylamine, and tetramethylethylenediamine; phosphites such as trimethyl phosphite, triethyl phosphite, tri-n-propyl phosphite, triisopropyl phosphite, tri-n-butyl phosphite, triisobutyl phosphite, diethyl n-butyl phosphite, and diethylphenyl phosphite; phosphates such as trimethyl phosphate, triphenyl phosphate, and tritolyl phosphate; acid amides such as acetic acid N,N-dimethylamide, benzoic acid N,N-diethylamide, and toluic acid N,N-dimethylamide; nitriles such as acetonitrile, benzonitrile, and tolunitrile; aliphatic carbonates such as dimethyl carbonate, diethyl carbonate, and ethylene carbonate; and pyridines such as pyridine, methylpyridine, ethylpyridine, and dimethylpyridine. These compounds used as the electron donor (a) may be used alone or in combination of two or more.

[0022] The above components can also be used in combination with electron donors disclosed in the section on magnesium compounds below, or ethers having 2 to 20 carbon atoms, such as methyl ether, ethyl ether, isopropyl ether, butyl ether, amyl ether, tetrahydrofuran, ethyl benzyl ether, ethylene glycol dibutyl ether, anisole, and diphenyl ether.

[0023] (Magnesium compounds) As the magnesium source used in preparing the solid titanium catalyst component (A) according to the present invention, a magnesium compound is used. When preparing the solid titanium catalyst component (A) according to the present invention, any known magnesium compound used in preparing a conventional solid titanium catalyst component can be used without limitation. A liquid magnesium compound is preferably used. When the magnesium compound is solid, it is preferably used in a liquefied form. The magnesium compound may be a reducing magnesium compound (Mg-1) or a non-reducing magnesium compound (Mg-2).

[0024] (Mg-1) Examples of magnesium compounds having reducing ability include organomagnesium compounds represented by the following formula: X n MgR 2-n (In the formula, n is 0≦n<2, R is hydrogen or an alkyl group, aryl group or cycloalkyl group having 1 to 20 carbon atoms, and when n is 0, the two Rs may be the same or different, and X is a halogen.)

[0025] Specific examples of such organic magnesium compounds having reducing ability include dialkyl magnesium compounds such as dimethyl magnesium, diethyl magnesium, dipropyl magnesium, dibutyl magnesium, diamyl magnesium, dihexyl magnesium, didecyl magnesium, octylbutyl magnesium, and ethylbutyl magnesium; alkyl magnesium halides such as ethyl magnesium chloride, propyl magnesium chloride, butyl magnesium chloride, hexyl magnesium chloride, and amyl magnesium chloride; alkyl magnesium alkoxides such as butylethoxy magnesium, ethylbutoxy magnesium, and octylbutoxy magnesium; and butyl magnesium hydride.

[0026] (Mg-2) Specific examples of magnesium compounds that do not have reducing ability include magnesium halides such as magnesium chloride, magnesium bromide, magnesium iodide, and magnesium fluoride; alkoxymagnesium halides such as methoxymagnesium chloride, ethoxymagnesium chloride, isopropoxymagnesium chloride, butoxymagnesium chloride, and octoxymagnesium chloride; allyloxymagnesium halides such as phenoxymagnesium chloride and methylphenoxymagnesium chloride; alkoxymagnesiums such as ethoxymagnesium, isopropoxymagnesium, butoxymagnesium, n-octoxymagnesium, and 2-ethylhexoxymagnesium; allyloxymagnesiums such as phenoxymagnesium and dimethylphenoxymagnesium; magnesium carboxylates such as magnesium laurate and magnesium stearate; magnesium metal; and magnesium hydride.

[0027] These magnesium compounds (Mg-2) that do not have reducing ability may be compounds derived from the magnesium compound (Mg-1) that has reducing ability described above, or compounds derived during the preparation of the catalyst component. To derive the magnesium compound (Mg-2) that does not have reducing ability from the magnesium compound (Mg-1) that has reducing ability, for example, the magnesium compound (Mg-1) that has reducing ability may be contacted with a halogen-containing compound such as an alcohol, a ketone, an ester, an ether, a siloxane compound, a halogen-containing silane compound, a halogen-containing aluminum compound, or an acid halide, or a compound having an OH group or an active carbon-oxygen bond.

[0028] Furthermore, in the present invention, (c) a compound (Mg-2) having no reducing ability can be derived from a magnesium compound (Mg-1) having reducing ability by using a known method such as an organosilicon compound or alcohol having no active hydrogen. The magnesium compounds may be used alone or in combination of two or more.

[0029] The magnesium compounds described above may form complex compounds or composite compounds with metal compounds other than magnesium, such as aluminum, zinc, boron, beryllium, sodium, and potassium, for example, organoaluminum compounds described below, or may be used in combination with these other metal compounds.

[0030] When preparing the solid titanium catalyst component (A), magnesium compounds other than those mentioned above can also be used, but it is preferable that the magnesium compound is present in the form of a halogen-containing magnesium compound in the finally obtained solid titanium catalyst component (A). Therefore, when a halogen-free magnesium compound is used, it is preferable to catalytically react it with a halogen-containing compound during the process of preparing the catalyst component.

[0031] Among the above compounds, magnesium compounds (Mg-2) having no reducing ability are preferred, and halogen-containing magnesium compounds are particularly preferred, and among these, magnesium chloride, alkoxy magnesium chloride, and allyloxy magnesium chloride are more preferably used.

[0032] In the present invention, when the magnesium compound is solid, it can be liquefied using an electron donor (Ce), such as alcohols, carboxylic acids, aldehydes, amines, or metal acid esters. Specific examples of alcohols include aliphatic alcohols such as methanol, ethanol, propanol, isopropyl alcohol, butanol, pentanol, hexanol, 2-methylpentanol, 2-ethylbutanol, heptanol, 2-ethylhexanol, octanol, decanol, dodecanol, tetradecyl alcohol, octadecyl alcohol, undecenol, oleyl alcohol, stearyl alcohol, and ethylene glycol; alicyclic alcohols such as cyclohexanol and methylcyclohexanol; aromatic alcohols such as benzyl alcohol, methylbenzyl alcohol, isopropylbenzyl alcohol, α-methylbenzyl alcohol, α,α-dimethylbenzyl alcohol, phenylethyl alcohol, cumyl alcohol, phenol, cresol, xylenol, ethylphenol, propylphenol, nonylphenol, and naphthol; alkoxy group-containing alcohols such as n-butyl cellosolve, ethyl cellosolve, 1-butoxy-2-propanol, and methyl carbitol; and halogen-containing alcohols such as trichloromethanol, trichloroethanol, and trichlorohexanol.

[0033] The carboxylic acids are preferably those having 7 or more carbon atoms, such as caprylic acid, 2-ethylhexanoic acid, nonylic acid, and undecylenic acid. The acetaldehydes are preferably those having 7 or more carbon atoms, such as caprylic aldehyde, 2-ethylhexyl aldehyde, undecyl aldehyde, benzaldehyde, tolualdehyde, and naphthaldehyde. The amines are preferably those having 6 or more carbon atoms, such as heptylamine, octylamine, 2-ethylhexylamine, nonylamine, decylamine, undecylamine, and laurylamine.

[0034] Examples of metal acid esters include tetraethoxytitanium, tetra-n-propoxytitanium, tetra-i-propoxytitanium, tetrabutoxytitanium, tetrahexoxytitanium, tetrabutoxyzirconium, and tetraethoxyzirconium. These metal acid esters do not include silicate esters such as (c) organosilicon compounds that do not have active hydrogen. Two or more of these can be used in combination. Among these, alcohols and metal acid esters are preferred, and alcohols having 6 or more carbon atoms are particularly preferred.

[0035] When using the electron donor (Ce) to liquefy a magnesium compound, if an electron donor (Ce) having 6 or more carbon atoms is used, it is usually used in an amount of about 1 mole or more, preferably 1 to 40 moles, and more preferably 1.5 to 12 moles, per mole of the magnesium compound. If an electron donor having 5 or fewer carbon atoms is used, it may usually require about 15 moles or more per mole of the magnesium compound at temperatures around room temperature. On the other hand, at high temperatures, for example, above 70°C, it is also possible to liquefy the magnesium compound in an amount of about 1 mole or more, preferably 1 to 40 moles, and more preferably 1.5 to 12 moles, per mole of the magnesium compound.

[0036] A hydrocarbon solvent can be used when contacting the solid magnesium compound with the electron donor (Ce). Examples of such hydrocarbon solvents include aliphatic hydrocarbons such as pentane, hexane, heptane, octane, decane, dodecane, tetradecane, and kerosene, alicyclic hydrocarbons such as cyclopentane, methylcyclopentane, cyclohexane, methylcyclohexane, cyclooctane, and cyclohexene, aromatic hydrocarbons such as benzene, toluene, xylene, ethylbenzene, cumene, and cymene, and halogenated hydrocarbons such as carbon tetrachloride, dichloroethane, dichloropropane, trichloroethylene, and chlorobenzene.

[0037] When aromatic hydrocarbons are used among these solvents, the electron donor (ce), for example, alcohols, can dissolve the magnesium compound when used in the amount shown above for the electron donor having 6 or more carbon atoms, regardless of its type (number of carbon atoms). When aliphatic hydrocarbons and / or alicyclic hydrocarbons are used, the alcohols as electron donors (ce) are used in an amount according to the number of carbon atoms as described above.

[0038] In the present invention, it is preferable to contact a solid magnesium compound with an electron donor (Ce) in a hydrocarbon solvent. To dissolve a solid magnesium compound in an electron donor (Ce), a common method is to contact the solid magnesium compound with the electron donor (Ce), preferably in the presence of a hydrocarbon solvent, and heat as needed. This contact is usually carried out at a temperature of 0 to 300°C, preferably 20 to 180°C, more preferably 50 to 150°C, for about 15 minutes to 20 hours, preferably about 30 minutes to 10 hours.

[0039] (liquid titanium compound) As the titanium source used in preparing the solid titanium catalyst component (A) according to the present invention, a liquid titanium compound is preferably used. In the present invention, a tetravalent titanium compound is particularly preferably used as the liquid titanium compound. Examples of such a tetravalent titanium compound include compounds represented by the following formula: Ti(OR) g X 4-g (wherein R is a hydrocarbon group, X is a halogen atom, and 0≦g≦4.)

[0040] Specific examples of such compounds include titanium tetrahalides such as TiCl, TiBr, and TiI; alkoxytitanium trihalides such as Ti(OCH)Cl, Ti(OCH)Cl, Ti(On-C4H)Cl, Ti(OCH)Br, and Ti(O-iso-C4H)Br; dialkoxytitanium dihalides such as Ti(OCH)Cl, Ti(OCH)Cl, Ti(On-C4H)Cl, and Ti(OCH)Br; trialkoxytitanium monohalides such as Ti(OCH)Cl, Ti(OCH)Cl, Ti(On-C4H)Cl, and Ti(OCH)Br; and tetraalkoxytitanium such as Ti(OCH), Ti(OCH)Cl, Ti(On-C4H)Cl, Ti(O-iso-C4H) and Ti(O-2-ethylhexyl). Among these, titanium tetrahalides are preferred, with titanium tetrachloride being particularly preferred. These titanium compounds can also be used in combination of two or more. Furthermore, they can be used by diluting them with a hydrocarbon solvent, as described above for liquefying the magnesium compound.

[0041] (Preparation of solid titanium catalyst component (A)) The solid titanium catalyst component (A) of the present invention can be produced by any known production method without any restrictions. As a specific method, the following method will be introduced as a preferred example. (1) A method in which a liquid magnesium compound, a liquid titanium compound and an electron donor (a) are contacted in any order. (2) A method of contacting a liquid containing a liquid magnesium compound and an electron donor (a) with a liquid titanium compound. (3) A method in which a magnesium compound in a liquid state at a high temperature is cooled with stirring to form a solid magnesium compound, which is then brought into contact with a liquid titanium compound and an electron donor (a).

[0042] The solid titanium catalyst component (A) according to the present invention prepared as described above contains magnesium, titanium, a halogen, and an electron donor (a). In this solid titanium catalyst component, the magnesium / titanium (atomic ratio) is 0.5 to 50, preferably 1 to 40, and more preferably 2 to about 30, and the halogen / titanium (atomic ratio) is 4 to 50, preferably 5 to 40, and more preferably 6 to 30.

[0043] The solid titanium catalyst component (A) may contain other components, such as a carrier, in addition to the above components, and specifically may contain the other components in an amount of 50% by mass or less, preferably 40% by mass or less, more preferably 30% by mass or less, and even more preferably 20% by mass or less. The composition of the catalyst component can be measured by ICP (atomic absorption spectroscopy), gas chromatography, etc. after thoroughly washing the solid titanium catalyst component with a large amount of hexane and drying it under conditions of 0.1 to 1 Torr and room temperature for 2 hours or more.

[0044] The shape of the solid titanium catalyst component (A) according to the present invention is preferably granular or nearly spherical, and its specific surface area is about 10 m 2 / g or more, preferably about 100 to 1000m 2 In the present invention, the solid titanium catalyst component (A) is usually used after washing with a hydrocarbon solvent.

[0045] ·Organometallic compound (B) The organometallic compound (B) (hereinafter also referred to as component (B)) used in the present invention may be any organic compound containing a metal atom, but is preferably an organoaluminum compound. A preferred embodiment of this compound can be represented by the following formula: R3Al (In the above formula, R is a hydrocarbon group having 1 to 20 carbon atoms, such as an alkyl group, a cycloalkyl group, or an aryl group, as well as a substituent selected from the group containing a halogen atom.)

[0046] In the present invention, the halogen atom includes an embodiment as a substituent that can be expressed as "Cl-", for example, in the case of a chlorine atom (the "-" is a symbol representing a covalent bond).

[0047] Specific examples of the substituent include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an isobutyl group, a pentyl group, a hexyl group, an octyl group, a cyclopentyl group, a cyclohexyl group, a phenyl group, a tolyl group, a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, and the like. Essential substituents include hydrocarbon groups having 1 to 20 carbon atoms such as an n-propyl group, an isopropyl group, an isobutyl group, a pentyl group, a hexyl group, an octyl group, a cyclopentyl group, a cyclohexyl group, a phenyl group, and a tolyl group, and halogen atoms such as a chlorine atom, a bromine atom, and an iodine atom.

[0048] Specific examples of essential organoaluminum compounds among these organoaluminum compounds include trialkylaluminums such as trimethylaluminum, triethylaluminum, triisopropylaluminum, triisobutylaluminum, trioctylaluminum, and tri-2-ethylhexylaluminum; alkenylaluminums such as isoprenylaluminum; dialkylaluminum halides such as dimethylaluminum chloride, diethylaluminum chloride, diisopropylaluminum chloride, diisobutylaluminum chloride, and dimethylaluminum bromide; alkylaluminum sesquihalides such as methylaluminum sesquichloride, ethylaluminum sesquichloride, isopropylaluminum sesquichloride, butylaluminum sesquichloride, and ethylaluminum sesquibromide; alkylaluminum dihalides such as methylaluminum dichloride, ethylaluminum dichloride, isopropylaluminum dichloride, and ethylaluminum dibromide; and alkylaluminum hydrides such as diisobutylaluminum hydride.

[0049] The above-mentioned organoaluminum compounds are preferred in the present invention. Among them, organoaluminum compounds having relatively small substituents, such as triethylaluminum, triisopropylaluminum, triisobutylaluminum, trioctylaluminum, diethylaluminum chloride, and ethylaluminum sesquichloride, are preferred.

[0050] Further examples of the organoaluminum compound include compounds represented by the following formula: R a n AlY 3-n In the above formula, R a is the same as above, and Y is -OR b Group, -OSiR c 3 groups, -OAlR d 2 units, -NR e 2 units, -SiR f 3 groups or -N(R g )AlR h 2 groups, n is 1 to 2, and R b , R c , R d and R h is a methyl group, an ethyl group, an isopropyl group, an isobutyl group, a cyclohexyl group, a phenyl group, etc., and R e is hydrogen, methyl group, ethyl group, isopropyl group, phenyl group, trimethylsilyl group, etc., and R f and R g is a methyl group, an ethyl group, etc.

[0051] Specific examples of such organoaluminum compounds include the following compounds: (i)R a n Al(OR b ) 3-n Dimethylaluminum methoxide, diethylaluminum ethoxide, diisobutylaluminum methoxide, etc. (ii)R a n Al(OSiR c 3) 3-n Et2Al(OSiMe3), (iso-Bu)2Al(OSiMe3), (iso-Bu)2Al(OSiEt3), etc. (iii)R a n Al(OAlR d 2) 3-n Et2AlOAlEt2, (iso-Bu)2AlOAl(iso-Bu)2, etc. (iv)R a n Al(NR e 2) 3-n Me2AlNEt2, Et2AlNHMe, Me2AlNHEt, Et2AlN(Me3Si)2, (iso-Bu)2AlN(Me3Si)2, etc. (v)R a n Al(SiR f 3) 3-n (iso-Bu)2AlSiMe3, etc. (vi)R a n Al〔N(R g )-AlR h 2) 3-n Et2AlN(Me)-AlEt2, (iso-Bu)2AlN(Et)-Al(iso-Bu)2, etc.

[0052] Other examples include similar compounds, such as organoaluminum compounds in which two or more aluminum atoms are bonded via oxygen or nitrogen atoms, such as (C2H5)2AlOAl(C2H5)2, (C4H9)2AlOAl(C4H9)2, (C2H5)2AlN(C2H5)Al(C2H5)2, and aluminoxanes such as methylaluminoxane.

[0053] Component (B) according to the present invention may also be a complex alkylation product of a Group I metal and aluminum. Examples of alkylated complexes of Group I metals and aluminum include compounds represented by the following general formula: M1 AlR j 4 (M 1 are Li, Na, and K, and R j is a hydrocarbon group having 1 to 15 carbon atoms.

[0054] Specific examples of such compounds include LiAl(C2H5)4, LiAl(C7H 15 )4 etc. These compounds can also be used in combination of two or more. The above R j is preferably a so-called hydrocarbon group containing only carbon and hydrogen.

[0055] Further examples of component (B) according to the present invention other than the organoaluminum compounds described above include organometallic compounds of metals in Group 2 of the periodic table, such as compounds represented by the following general formula: R k R l M 2 (R k , R l are hydrocarbon groups having 1 to 15 carbon atoms or halogens, and may be the same or different, except for the case where both are halogens. 2 are Mg, Zn, and Cd.)

[0056] Specific examples include diethyl zinc, diethyl magnesium, butylethyl magnesium, ethyl magnesium chloride, and butyl magnesium chloride. The organometallic compounds can be used alone or in combination with the organoaluminum compounds, in which case the proportion of the RAl, calculated as metal atoms such as aluminum and magnesium, is preferably 50 mol % or less, more preferably 30 mol % or less, even more preferably 10 mol % or less, and particularly preferably 5 mol % or less.

[0057] Compounds (C) containing two or more ether bonds via multiple atoms As the compound (C) having two or more ether bonds via a plurality of atoms used in the present invention (hereinafter sometimes referred to as polyether compound (C) or component (C)), known compounds can be used without limitation. The polyether compound (C) is preferably a compound having two or more ether bonds via a plurality of carbon atoms, and more specifically, a compound represented by the following formula:

[0058] [ka]

[0059] In the above formula, m is an integer of 2≦m≦10, more preferably an integer of 3≦m≦10, and R 11 , R 12 , R 31 ~R 36 are each independently a hydrogen atom or a substituent having at least one element selected from carbon, hydrogen, oxygen, fluorine, chlorine, bromine, iodine, nitrogen, sulfur, phosphorus, boron and silicon.

[0060] When m is 2 or more, there are multiple R 11 and R 12 may be the same or different. 11 , R 12 , R 31 ~R 36 , preferably R 11 and R 12 may combine to form a ring other than a benzene ring.

[0061] Specific examples of such compounds include: 2-Isopropyl-1 , 3-Dimethoxypropane, 2-s-butyl-1 , 3-Dimethoxypropane, 2-cumyl-1 , 1-substituted dialkoxypropanes such as 3-dimethoxypropane; 2-Isopropyl-2-isobutyl-1 , 3-Dimethoxypropane, 2, 2-Dicyclohexyl-1 , 3-Dimethoxypropane, 2-methyl-2-isopropyl-1 , 3-Dimethoxypropane, 2-methyl-2-cyclohexyl-1 , 3-Dimethoxypropane, 2-methyl-2-isobutyl-1 , 3-Dimethoxypropane, 2 , 2-Diisobutyl-1 , 3-Dimethoxypropane, 2 , 2-bis(cyclohexylmethyl)-1 , 3-Dimethoxypropane, 2 , 2-Diisobutyl-1 , 3-diethoxypropane, 2 , 2-Diisobutyl-1 , 3-Dibutoxypropane, 2 , 2-di-s-butyl-1 , 3-Dimethoxypropane, 2 , 2-Dineopentyl-1 , 3-Dimethoxypropane, 2-isopropyl-2-isopentyl-1 , 3-Dimethoxypropane, 2-cyclohexyl-2-cyclohexylmethyl-1 , 2-substituted dialkoxypropanes such as 3-dimethoxypropane; 2 , 3-Dicyclohexyl-1 , 4-Diethoxybutane, 2 , 3-Dicyclohexyl-1 , 4-Diethoxybutane, 2 , 3-Diisopropyl-1 , 4-Diethoxybutane, 2 , 4-diphenyl-1 , 5-Dimethoxypentane, 2 , 5-diphenyl-1 , 5-Dimethoxyhexane, 2 , 4-Diisopropyl-1 , 5-Dimethoxypentane, 2 , 4-Diisobutyl-1 , 5-Dimethoxypentane, 2 , 4-Diisoamyl-1 ,Dialkoxyalkanes such as 5-dimethoxypentane; 2-methyl-2-methoxymethyl-1 , 3-Dimethoxypropane, 2-cyclohexyl-2-ethoxymethyl-1 , 3-Diethoxypropane, 2-cyclohexyl-2-methoxymethyl-1 , trialkoxyalkanes such as 3-dimethoxypropane; 2 , 2-Diisobutyl-1 , 3-Dimethoxy-4-cyclohexenyl, 2-isopropyl-2-isoamyl-1 , 3-Dimethoxy-4-cyclohexenyl, 2-cyclohexyl-2-methoxymethyl-1 , 3-Dimethoxy-4-cyclohexenyl, 2-isopropyl-2-methoxymethyl-1 , 3-Dimethoxy-4-cyclohexenyl, 2-isobutyl-2-methoxymethyl-1 , 3-Dimethoxy-4-cyclohexenyl, 2-cyclohexyl-2-ethoxymethyl-1 , 3-Dimethoxy-4-cyclohexenyl, 2-isopropyl-2-ethoxymethyl-1 , 3-Dimethoxy-4-cyclohexenyl, 2-isobutyl-2-ethoxymethyl-1 , Dialkoxycycloalkanes such as 3-dimethoxy-4-cyclohexenyl Examples include:

[0062] Of these, 1 , 3-diethers are preferred, especially 2-isopropyl-2-isobutyl-1 , 3-Dimethoxypropane, 2 , 2-Diisobutyl-1 , 3-Dimethoxypropane, 2-isopropyl-2-isopentyl-1 , 3-Dimethoxypropane, 2 , 2-Dicyclohexyl-1 , 3-Dimethoxypropane, 2 , 2-Bis(cyclohexylmethyl) 1 , 3-Dimethoxypropane is preferred. These compounds may be used singly or in combination of two or more.

[0063] Catalyst component (I) The catalyst component (I) according to the present invention is obtained by contacting the above-mentioned solid titanium catalyst component (A) (component (A)), organometallic compound (B) (component (B)), and polyether compound (C) (component (C)) under conditions that satisfy the following requirement (α): (α) The molar ratio ([B] / [C]) of the number of moles of metal atoms contained in the component (B) [B] to the number of moles of the component (C) [C] is 1 or more and 9.5 or less.

[0064] The lower limit of the [B] / [C] ratio is preferably 1.1, more preferably 1.5, even more preferably 2, particularly preferably 2.3, and especially preferably 2.5, while the upper limit is preferably 9, more preferably 8, even more preferably 7, and particularly preferably 6.5.

[0065] When ethylene and an olefin having 4 to 20 carbon atoms are polymerized in the presence of catalyst component (I), which is obtained by contacting the components under conditions satisfying the molar ratio ([B] / [C]) within the above-described range, a higher molecular weight ethylene copolymer than conventional ethylene copolymers tends to be obtained without a significant decrease in the content of structural units derived from the olefin having 4 to 20 carbon atoms. Ethylene generally has a faster polymerization rate than propylene or olefins having 4 or more carbon atoms, and chain transfer tends to be less likely to occur. For this reason, it has been thought that a solid titanium catalyst component, which is likely to produce a high molecular weight ethylene copolymer, is unlikely to produce a copolymer having a relatively high content of structural units derived from the olefin having 4 or more carbon atoms; in other words, its copolymerizability tends to be reduced. However, the polymerization of ethylene and an olefin having 4 to 20 carbon atoms in the presence of catalyst component (I) according to the present invention surprisingly tends to produce a high molecular weight ethylene copolymer without impairing its copolymerizability.

[0066] The reason why the catalyst component (I) according to the present invention exhibits the above-mentioned effects is unclear, but the present inventors speculate as follows. Polyether compound (C) is a stable substance that does not substantially react with organometallic compound (B) and is thought to have relatively high electron donating properties. Therefore, it has a high electron donating effect on organometallic compound (B) through its interaction with organometallic compound (B), and it is thought that it tends to suppress chain transfer reactions by slightly reducing the Lewis acidity of organometallic compound (B). On the other hand, polyether compound (C) has relatively strong electron donating properties, and therefore tends to have a strong interaction with ethylene, which is simpler than olefins with three or more carbon atoms and is thought to have a high electron density relative to its molecular weight. Therefore, it slightly reduces the polymerization reactivity of ethylene, and therefore the copolymerization reactivity of ethylene with propylene and olefins with four or more carbon atoms, so-called α-olefins, is thought to show a relatively high tendency for α-olefins to dominate.

[0067] If the amount of polyether compound (C) is too small compared to the organometallic compound (B), it becomes difficult to achieve the above-mentioned functions. On the other hand, if the amount of polyether compound (C) is too large, the interaction with the α-olefin will be strong, and the polymerization reactivity of the α-olefin will decrease, as with ethylene. As a result, the dominance of the α-olefin over ethylene will decrease, and copolymerization will also tend to decrease.

[0068] Of course, the influence of the electron donor (a) contained in the solid titanium catalyst component (A) may not be negligible in the above effects. On the other hand, the influence of the polyether compound (C) tends to be dominant in relation to the organometallic compound (B), in terms of its stability as a compound, the strength of its electron donating ability, and the amount.

[0069] In the present invention, by contacting the solid titanium catalyst component (A), the organometallic compound (B), and the polyether compound (C) under conditions that satisfy the above-mentioned requirement (α), an environment can be formed that provides an excellent balance of properties such as copolymerization reactivity and high molecular weight production, and therefore the present inventors believe that the catalyst component (I) according to the present invention exhibits the above-mentioned unique properties.

[0070] In the production of catalyst component (I) according to the present invention, the molar ratio ([B] / [Ti]) of the number of moles of metal atoms in organometallic compound (B) [B] to the number of moles of titanium atoms in solid titanium catalyst component (A) [Ti] is preferably 1 to 50. The lower limit is more preferably 1.5, even more preferably 2, and particularly preferably 2.5. On the other hand, the upper limit is more preferably 35, even more preferably 20, particularly preferably 9.5, and especially preferably 8. Among the above, it is preferable to satisfy the following requirement (β). (β) The molar ratio ([B] / [Ti]) of the number of moles of titanium atoms [Ti] contained in the component (A) to the number of moles of metal atoms [B] contained in the component (B) is 1 or more and 9.5 or less.

[0071] If the ratio of the organometallic compound (B) in the catalyst component (I) according to the present invention is too high, the electron donor (a) in the solid titanium catalyst component (A) may be altered or an excessive reduction reaction of titanium may occur. If the ratio of the organometallic compound (B) is too low, the amount of the polyether compound (C) will also be relatively reduced. In either case, the effect aimed at by the present invention may be insufficient.

[0072] <Method of producing ethylene copolymer> In the method for producing an ethylene copolymer according to the present invention, i.e., the method for polymerizing a monomer containing ethylene (main polymerization), an olefin containing ethylene and an olefin having 4 to 20 carbon atoms may be polymerized in the presence of the catalyst component (I) alone, as described above. Alternatively, an olefin containing ethylene and an olefin having 4 to 20 carbon atoms may be polymerized in the presence of a polymerization catalyst comprising the catalyst component (I) and other components. A preferred embodiment of the polymerization catalyst containing components other than the catalyst component (I) is to polymerize an olefin containing ethylene and an olefin having 4 to 20 carbon atoms in the presence of an ethylene polymerization catalyst comprising the catalyst component (I) and an organometallic compound (II). Any of the compounds described above as the organometallic compound (B) can be used as the organometallic compound (II), and an organoaluminum compound is preferably used. The organoaluminum compound can be any of the organoaluminum compounds described above as examples of the organometallic compound (B).

[0073] Specific examples of the olefins having 4 to 20 carbon atoms to be copolymerized with ethylene include 1-butene, 1-pentene, 1-hexene, 3-methyl-1-butene, 3-methyl-1-pentene, 3-ethyl-1-pentene, 4-methyl-1-pentene, 4,4-dimethyl-1-pentene, 4-methyl-1-hexene, 4,4-dimethyl-1-hexene, 4-ethyl-1-hexene, 3-ethyl-1-hexene, 1-octene, 1-decene, 1-dodecene, 1-tetradecene, 1-hexadecene, 1-octadecene, and 1-eicosene. Furthermore, vinyl compounds, other unsaturated compounds, polyene compounds, etc. can also be copolymerized, and examples thereof include aromatic vinyl compounds such as styrene, substituted styrenes, allylbenzene, substituted allylbenzenes, vinylnaphthalenes, substituted vinylnaphthalenes, allylnaphthalene, and substituted allylnaphthalenes; alicyclic vinyl compounds such as vinylcyclopentane, substituted vinylcyclopentanes, vinylcyclohexane, substituted vinylcyclohexanes, vinylcycloheptane, substituted vinylcycloheptane, and allylnorbornane; Cyclic olefins such as cyclopentene, cycloheptene, norbornene, 5-methyl-2-norbornene, tetracyclododecene, and 2-methyl-1,4,5,8-dimethano-1,2,3,4,4a,5,8,8a-octahydronaphthalene, and silane-based unsaturated compounds such as allyltrimethylsilane, allyltriethylsilane, 4-trimethylsilyl-1-butene, 6-trimethylsilyl-1-hexene, 8-trimethylsilyl-1-octene, and 10-trimethylsilyl-1-decene can also be copolymerized.

[0074] Two or more of the above-mentioned olefins having 4 to 20 carbon atoms can also be copolymerized with ethylene. In the present invention, in the polymerization of a monomer containing ethylene, the catalyst component (I) is preferably used in an amount of usually about 0.0001 to 1.0 millimole, calculated as titanium atoms, per liter of polymerization volume. The organometallic compound (II) is preferably used in an amount such that the metal atoms, such as aluminum atoms, in the catalyst component (II) are usually about 1 to 2,000 moles, preferably about 5 to 500 moles, per mole of titanium atoms in the catalyst component (I) in the polymerization system.

[0075] The polymerization can be carried out by either a liquid phase polymerization method such as solution polymerization or suspension polymerization, or a gas phase polymerization method. When the polymerization is carried out in the form of a slurry polymerization reaction, an organic solvent inert to polymerization is usually used as the polymerization solvent. Specific examples of the organic solvent include aliphatic hydrocarbons such as propane, butane, pentane, hexane, heptane, octane, decane, dodecane, and kerosene; alicyclic hydrocarbons such as cyclopentane, cyclohexane, and methylcyclopentane; aromatic hydrocarbons such as benzene, toluene, and xylene; and halogenated hydrocarbons such as ethylene chloride and chlorobenzene. These may be used in combination. Furthermore, a copolymerizable monomer that is liquid at the reaction temperature may be used together with the organic solvent.

[0076] The polymerization conditions vary depending on the type of polymerization or the type of ethylene copolymer to be obtained, but the polymerization is usually carried out at a temperature of about 20 to 300°C, preferably about 50 to 150°C, under atmospheric pressure of 100 kg / cm. 2 Preferably about 2 to 50 kg / cm 2 This is done under pressure.

[0077] The molecular weight of the resulting polymer can be adjusted by using hydrogen during polymerization. The polymerization can be carried out in any of batch, semi-continuous, and continuous modes. Furthermore, the polymerization can be carried out in two or more stages by changing the reaction conditions.

[0078] In the present invention, the catalyst component (I) described above is used in the polymerization of olefins, and thus high-molecular-weight olefin polymers can be produced with high polymerization activity while exhibiting good copolymerizability. The resulting ethylene copolymer has a low catalyst content, particularly a low halogen content, per polymer unit, and is less susceptible to mold rusting during molding. Furthermore, the resulting ethylene copolymer has a low fine powder content and excellent particle properties, so it may be used without pelletizing.

[0079] <Ethylene copolymer> In the method for producing the ethylene copolymer of the present invention, the content of structural units derived from ethylene is 50 mol % or more and 99.8 mol % or less, and the density is 900 to 960 kg / m 3 In particular, the method for producing an ethylene copolymer of the present invention tends to easily produce an ethylene copolymer having a high content of structural units derived from an olefin having 4 or more carbon atoms and a high molecular weight. The ethylene copolymer obtained by the method for producing an ethylene copolymer of the present invention preferably has a content of structural units derived from ethylene of 50 mol% or more and 99.8 mol% or less, and a content of structural units derived from an olefin having 4 to 20 carbon atoms of 0.2 mol% or more and 50 mol% or less. The lower limit of the content of the structural units derived from ethylene is preferably 70 mol%, more preferably 90 mol%, even more preferably 95 mol%, and particularly preferably 97 mol%. The preferred lower limit of the density of the ethylene copolymer obtained by the method for producing an ethylene copolymer of the present invention is 910 kg / m 3 , more preferably 915 kg / m 3 , and more preferably 920 kg / m 3 , particularly preferably 925 kg / m 3 is.

[0080] The content of the structural units derived from ethylene and olefins as described above is 13 NMR measurement is performed using a C NMR device, and peaks characteristic of the corresponding olefin are assigned in a conventional manner, followed by area quantification. Alternatively, if IR measurement is performed on various olefin polymers with different compositions and a calibration curve is prepared, the content of the olefin-derived structural unit can also be determined by IR measurement. In the examples of the present invention, the content of the olefin-derived structural unit can be determined by the latter method using IR measurement.

[0081] Other preferred physical properties of the ethylene copolymer obtained in the present invention include the following. The bulk density is desirably 0.20 to 0.60 g / ml, and preferably 0.25 to 0.60 g / ml. The melt flow rate MFR (based on ASTS D1238E, 190°C) is preferably 0.01 to 100 g / 10 min. The intrinsic viscosity [η] measured in decalin at 135° C. is 1.5 to 30 dl / g, and more preferably 2.0 to 25 dl / g. As described above, the catalyst component (I) of the present invention can be used to produce polymers having molecular weights and melt fluidity suited to the intended use by conventional methods.

[0082] The ethylene copolymer obtained by the present invention as described above may also be blended with a heat stabilizer, a weather stabilizer, an antistatic agent, an antiblocking agent, a lubricant, a nucleating agent, a pigment, a dye, an inorganic or organic filler, etc., as required.

[0083] The ethylene copolymer obtained by the production method of the present invention can be suitably used as a raw polymer for films, containers, etc. It is particularly suitable as a raw polymer for containers obtained as films or blow-molded articles, etc. [Example]

[0084] The present invention will be explained in more detail below based on examples, but the present invention is not limited to these examples.

[0085] [Measurement and evaluation method] In the following examples, the composition of the solid titanium catalyst component for ethylene polymerization, and the intrinsic viscosity, density and content of butene-derived structural units of the ethylene copolymer were measured as follows. <Magnesium and titanium content> Measurement was performed by ICP analysis (Shimadzu Corporation, ICPF 1000TR). <Chlorine content> It was measured by silver nitrate titration.

[0086] <Alcohol residue content> The thoroughly dried catalyst was added to a 10% by weight water solution in acetone, and the alcohol obtained by hydrolysis was quantified by gas chromatography. <Intrinsic viscosity [η]> The intrinsic viscosity [η] was measured in decalin at a temperature of 135° C. by dissolving the ethylene copolymer in decalin and using a fully automatic viscosity measuring device (VMR-053UPC manufactured by Rigo Co., Ltd.).

[0087] <density> Using a hydraulic heat press set at 190°C, the sample was heated and melted at a pressure of 5 MPa, then cooled at a pressure of 15 MPa and an average cooling rate of 15±5°C / min to produce a pressed sheet. (Spacer shape: 65×12×2 (mm) on a 200×200×2 (mm) thick plate, 4 cavities) The pressed sheet was boiled for 30 minutes, and then cooled together with the boiling water in a laboratory atmosphere for at least 1 hour, after which the density was measured using a density gradient tube.

[0088] <Butene-derived structural unit content> The comonomer content of the copolymer was measured by FT-IR (FT-IR4100 infrared spectrophotometer manufactured by JASCO Corporation). FT-IR was performed using a film obtained by melt-stretching the copolymer polymer obtained in the examples in a hot press heated to 180°C and then cooling it under pressure at room temperature as a measurement sample. -1 ~400cm -1 The butene content was measured by the C-CH2CH3 skeletal vibration (1378 cm) based on butene. -1 ) was used as the key band, and the absorbance of the key band (D1378) and the internal standard band (4321 cm -1 The ratio of the absorbance (D4321) of the CH stretching vibration to the methylene and methyl bending vibration (D1378 / D4321) was calculated. On the other hand, the content of butene-derived structural units in advance 13 For several types of ethylene / butene copolymers whose properties have been determined by methods such as C NMR, the [D1378 / D4321] values ​​were obtained by the above method, and based on these values, a calibration curve was created showing the relationship between the [D1378 / D4321] value and the butene content (the number of butene-derived structural units per 1,000 carbon atoms was used as the evaluation value). The butene-derived structural unit content (the number of butene-derived structural units per 1000 carbon atoms) was determined from this calibration curve and the measured values ​​of [D1378 / D4321] using the polymers of the Examples and Comparative Examples.

[0089] [Example 1] "Preparation of solid titanium catalyst component (A)" 95.2 g of anhydrous magnesium chloride, 442 ml of decane, and 390.6 g of 2-ethylhexyl alcohol (EHA, 2-ethylhexanol) were reacted by heating at 140°C for 4 hours to form a homogeneous solution, and then 21.3 g of phthalic anhydride was added, and the mixture was further reacted by heating at 130°C for 1 hour, and then slowly cooled to room temperature. 75 ml of the homogeneous solution thus obtained was added dropwise to 200 ml of titanium tetrachloride at -20°C over 1 hour with stirring. After the addition was complete, the temperature of the mixture was raised to 110°C over 4 hours. When the temperature reached 110°C, 5.22 g of diisobutyl phthalate was added, and the mixture was then maintained at the same temperature with stirring for 2 hours. The solid was then filtered at the same temperature to separate the solid. The solid was resuspended in 275 ml of titanium tetrachloride and heated again at 110°C for 2 hours. After the reaction was complete, the solid was collected by hot filtration again and thoroughly washed with decane at 110°C and then with hexane at room temperature until no free titanium compounds were detected, yielding a solid titanium catalyst component (A). The resulting solid titanium catalyst component (A) was stored as a decane suspension, and a portion was dried for analysis. Its composition was 2.4% by weight of titanium, 60% by weight of chlorine, 20% by weight of magnesium, and 13% by weight of diisobutyl phthalate.

[0090] "Preparation of catalyst component (I-1)" In a nitrogen atmosphere, 18 ml of decane, 4.9 mmol of triethylaluminum (TEA), 4.0 mmol of 2-isopropyl-2-isobutyl-1,3-dimethoxypropane, and 0.16 mmol (in terms of titanium atom) of the solid titanium catalyst component (A) obtained above were placed in a glass reactor and stirred at room temperature for 10 minutes to obtain catalyst component (I-1).

[0091] "polymerization" An autoclave having an internal volume of 1 liter was charged with 500 ml of purified n-heptane under a nitrogen atmosphere, and the decane suspension of the catalyst component (I-1) obtained above was added in an amount equivalent to 0.15 mmol in terms of titanium atom. The temperature was then raised to 72°C, and hydrogen diluted with nitrogen was fed at 0.01 MPa to give a hydrogen concentration of 5 mol%, and then an ethylene / butene mixed gas having a butene concentration of 2 mol% was continuously fed so that the total pressure became 0.1 MPaG, and the mixture was maintained for 76 minutes (corresponding to the polymerization time). After the polymerization was completed, the ethylene copolymer was filtered from the n-heptane solvent, washed, and dried. After drying, 25.2 g of powdery polymer was obtained. The intrinsic viscosity [η] of this powdery polymer was 12.4 dl / g and the density was 935 kg / m 3 The butene-derived structural unit content was 6.1 / 1000C, and the activity was 0.06 kg-PE / (g-cat·h).

[0092] [Example 2] "Preparation of catalyst component (I-2)" Catalyst component (I-2) was obtained by stirring 18 ml of decane, 1.6 mmol of triethylaluminum (TEA), 0.81 mmol of 2-isopropyl-2-isobutyl-1,3-dimethoxypropane (B) and 0.16 mmol of the above solid titanium catalyst component (A) in terms of titanium atom in a nitrogen atmosphere in a glass reactor at room temperature for 10 minutes. "polymerization" Copolymerization of ethylene and butene was carried out in the same manner as in Example 1, except that the catalyst component (I-2) obtained above was used instead of the catalyst component (I-1) and the polymerization time was 48 minutes. The results are shown in Table 1.

[0093] [Example 3] "Preparation of catalyst component (I-3)" In a nitrogen atmosphere, 18 ml of decane, 0.97 mmol of triethylaluminum (TEA), 0.16 mmol of 2-isopropyl-2-isobutyl-1,3-dimethoxypropane (B), and 0.16 mmol of the above solid titanium catalyst component (A) in terms of titanium atom were placed in a glass reactor and stirred at room temperature for 10 minutes to obtain catalyst component (I-3). "polymerization" Copolymerization of ethylene and butene was carried out in the same manner as in Example 1, except that the catalyst component (I-3) obtained above was used instead of the catalyst component (I-1) and the polymerization time was 37 minutes. The results are shown in Table 1.

[0094] [Example 4] "Preparation of catalyst component (I-4)" In a nitrogen atmosphere, 18 ml of decane, 0.97 mmol of triethylaluminum (TEA), 0.32 mmol of 2-isopropyl-2-isobutyl-1,3-dimethoxypropane (B), and 0.32 mmol of the above solid catalyst component (A) in terms of titanium atom were stirred in a glass reactor at room temperature for 10 minutes to obtain catalyst component (I-4). "polymerization" Copolymerization of ethylene and butene was carried out in the same manner as in Example 1, except that the catalyst component (I-4) obtained above was used instead of the catalyst component (I-1) and the polymerization time was 41 minutes. The results are shown in Table 1.

[0095] [Comparative Example 1] "polymerization" A 1-liter autoclave was charged with 500 ml of purified n-heptane under a nitrogen atmosphere, and 3.9 mmol of triethylaluminum (TEA) and a decane suspension of the solid titanium catalyst component (A) (equivalent to 0.15 mmol of titanium atoms) were added. The temperature was then raised to 72°C, and hydrogen diluted with nitrogen was fed at 0.01 MPa to a hydrogen concentration of 5 mol%, followed by continuous feeding of an ethylene / butene mixed gas with a butene concentration of 2 mol% to a total pressure of 0.1 MPaG. Copolymerization of ethylene and butene was carried out for 101 minutes. The results are shown in Table 1.

[0096] [Table 1]

[0097] [Example 5] "Preparation of catalyst component (I-5)" A catalyst component (I-5) was obtained in the same manner as in Example 1, except that 2-methyl-2-n-propyl-1,3-diethoxypropane was used instead of 2-isopropyl-2-isobutyl-1,3-dimethoxypropane (B) and the conditions shown in Table 2 were used. "polymerization" Copolymerization of ethylene and butene was carried out in the same manner as in Example 1, except that the catalyst component (I-5) obtained above was used instead of the catalyst component (I-1) and the polymerization time was 53 minutes. The results are shown in Table 2.

[0098] [Example 6] "Preparation of catalyst component (I-6)" A catalyst component (I-6) was obtained in the same manner as in Example 1, except that 2-methyl-2-n-propyl-1,3-dimethoxypropane was used instead of 2-isopropyl-2-isobutyl-1,3-dimethoxypropane (B) and the conditions shown in Table 2 were used. "polymerization" Copolymerization of ethylene and butene was carried out in the same manner as in Example 1, except that the catalyst component (I-6) obtained above was used instead of the catalyst component (I-1) and the polymerization time was 58 minutes. The results are shown in Table 2.

[0099] [Table 2]

[0100] In Comparative Example 1, the polymerization activity was low, and the result was that the intrinsic viscosity [η] of the obtained ethylene copolymer was low and the content of the butene-derived structural unit was also low.

Claims

1. (A) a solid titanium catalyst component containing magnesium, titanium, a halogen, and an electron donor (a); (B) an organometallic compound, and (C) A compound having two or more ether bonds present via a plurality of atoms, Catalyst component (I) obtained by contacting under conditions satisfying the following (α): In the presence of A method for producing an ethylene copolymer, comprising polymerizing ethylene and an olefin containing an olefin having 4 to 20 carbon atoms. (α) The molar ratio ([B] / [C]) of the number of moles of metal atoms contained in the component (B) [B] to the number of moles of the component (C) [C] is 1 or more and 9.5 or less. (However, the electron donor (a) is a compound selected from a silicon-containing compound, an organic acid compound, an organic acid ester compound, a ketone compound, an aldehyde compound, a nitrogen-containing compound, and a phosphorus-containing compound.)

2. The catalyst component (I) comprises the components (A), (B) and (C), The method for producing an ethylene copolymer according to claim 1 , wherein the catalyst component is obtained by contacting under conditions that satisfy the following (β): (β) The molar ratio ([B] / [Ti]) of the number of moles of titanium atoms [Ti] contained in the component (A) to the number of moles of metal atoms [B] contained in the component (B) is 1 or more and 9.5 or less.

3. 2. The method for producing an ethylene copolymer according to claim 1, wherein the component (C) is a compound having two or more ether bonds present via a plurality of carbon atoms.

4. The method for producing an ethylene copolymer according to claim 1, wherein the electron donor (a) is an organic acid ester compound.

5. The method for producing an ethylene copolymer according to claim 1, wherein the ethylene copolymer has a content of ethylene-derived structural units of 50 mol% or more.

6. 3. The method for producing an ethylene copolymer according to claim 2, wherein the ratio [B] / [C] is 1.5 or more and 9 or less, and the ratio [B] / [Ti] is 1.5 or more and 9 or less.

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