Method for producing solid titanium catalyst component and method for producing ethylene polymer

Abstract

To provide a solid titanium catalyst component that enables production of an olefin polymer with low molecular weight using a relatively small amount of hydrogen and with superior polymerization activity.SOLUTION: A method for producing a solid titanium catalyst component containing magnesium, titanium, and halogen, the method comprising a step of bringing (a) a liquid magnesium compound, (c) an organosilicon compound having no active hydrogen, and (b) a specific liquid halogen-containing titanium compound into contact with each other, heating the obtained contact product (i) to a temperature in the range of 105-115°C, and holding it at this temperature.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a method for producing a solid titanium catalyst component and a method for producing an ethylene polymer. [Background technology]

[0002] Olefin polymers such as ethylene homopolymers and linear low-density ethylene polymers (LLDPE) have excellent transparency and mechanical strength, and are widely used as raw materials for applications such as packaging materials and containers, such as films and bottles. Various methods for producing such ethylene polymers have been disclosed, 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 (see, for example, Patent Document 1). The particle properties of the solid titanium catalyst tend to have a significant impact 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 raw materials for containers as an alternative to glass, 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, etc. (e.g., Patent Document 2). In response to this trend, various standards have been established, such as PE100, PE100-RC, and PE125. [Prior art documents] [Patent documents]

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

[0005] Olefin polymers having excellent durability as described above often contain components with extremely high molecular weights. Appropriate toughness is also required. It is preferable that such olefin polymers contain olefin polymer components with as high a molecular weight as possible. It is further considered preferable that the high-molecular-weight olefin polymer component contains a relatively large amount of structural units derived from olefins having 3 or more carbon atoms.

[0006] On the other hand, since such olefin polymers are also required to have excellent moldability, they often contain low-molecular-weight olefin polymers. Conventionally known solid titanium catalyst components have tended to easily produce olefin polymers with relatively high molecular weights (especially high-molecular-weight ethylene polymers). For this reason, to produce low-molecular-weight olefin polymers using solid titanium catalyst components, a large amount of hydrogen is used in combination to reduce the molecular weight through a chain transfer reaction. On the other hand, the use of a large amount of hydrogen can reduce the partial pressure of the olefin and slow the production rate of the olefin polymer. Furthermore, the reaction pressure can become high, which can require a highly pressure-resistant reactor (which is expensive and subject to strict legal regulations).

[0007] Therefore, an object of the present invention is to provide a solid titanium catalyst component that can produce olefin polymers having a low molecular weight (high melt flow rate (MFR)) with a relatively small amount of hydrogen with excellent polymerization activity. [Means for solving the problem]

[0008] As a result of investigations conducted by the present inventors to solve the above-mentioned problems, they found that a method for producing a solid titanium catalyst using a specific titanium compound provides a solid titanium catalyst component that can solve the above-mentioned problems, and thus completed the present invention.

[0009] That is, the present invention is specified by the following requirements. [1] (a) a liquid magnesium compound; (c) an organosilicon compound having no active hydrogen; (b) contacting a liquid halogen-containing titanium compound satisfying the following formula (1): A method for producing a solid titanium catalyst component containing magnesium, titanium, and a halogen, comprising the steps of heating the resulting contact product (i) to a temperature in the range of 105 to 115°C and maintaining the temperature. (R 11 -CR 12 2-O) β -Ti-X γ ···(1) (R 11 is a group selected from a hydrogen atom and a hydrocarbon group having 1 to 5 carbon atoms, R 12 is a group selected from a hydrogen atom and a hydrocarbon group having 1 to 2 carbon atoms, R 11 , R 12 If both are hydrocarbon groups, R 11 Number of carbon atoms in ≧ R 12 is the number of carbon atoms, R 11 and R 12 The sum of the number of carbon atoms is 7 or less, X is a halogen atom, β and γ are positive real numbers, 2≦β+γ≦4) [2] (a) For 1 mole of liquid magnesium compound, (c) The method for producing a solid titanium catalyst component according to the above [1], wherein the organosilicon compound having no active hydrogen is used in a proportion of 0.25 to 0.35 moles. [3] The method for producing a solid titanium catalyst component according to the above [1] or [2], wherein β is 1.5 or less. [4] (b) The method for producing a solid titanium catalyst component according to any one of the above [1] to [3], wherein the liquid halogen-containing titanium compound is a reaction product of a titanium halide and an alcohol compound. [5] A method for producing an ethylene polymer, comprising polymerizing olefins including ethylene in the presence of an ethylene polymerization catalyst comprising a solid titanium catalyst component (A) obtained by the method according to any one of the above [1] to [4] and an organometallic compound (B). [Effects of the Invention]

[0010] When a solid titanium catalyst component is produced by the above method and used in combination with an organometallic compound as an olefin polymerization catalyst to polymerize olefins such as ethylene, olefin polymers having relatively low molecular weights can be produced with excellent polymerization activity. DETAILED DESCRIPTION OF THE INVENTION

[0011] The method for producing a solid titanium catalyst component according to the present invention, the olefin polymerization catalyst containing the solid titanium catalyst component, and the olefin polymerization method 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. For example, the term "ethylene polymer" is sometimes used to mean not only ethylene homopolymer but also copolymer of ethylene and other olefin.

[0012] <Method of manufacturing a solid titanium catalyst component> The method for producing the solid titanium catalyst component according to the present invention is characterized by comprising the step of contacting (a) a liquid magnesium compound, (c) an organosilicon compound having no active hydrogen, and (b) a specific liquid halogen-containing titanium compound, which will be described later. The solid titanium catalyst component thus obtained (hereinafter sometimes referred to as solid titanium catalyst component (A)) contains magnesium, titanium, a halogen, and silicon. First, the components used in preparing the solid titanium catalyst component of the present invention will be described below.

[0013] <(a) Liquid magnesium compound> In the present invention, when preparing the solid titanium catalyst component, the magnesium compound is used in a liquid state, and when the magnesium compound is in a solid state, it is liquefied before use. As the magnesium compound, a magnesium compound (a-1) having reducing ability and a magnesium compound (a-2) having no reducing ability can be used.

[0014] (a-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 R may be the same or different. X is a halogen.

[0015] 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.

[0016] (a-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.

[0017] These magnesium compounds (a-2) without reducing ability may be compounds derived from the magnesium compounds (a-1) with reducing ability described above, or compounds derived during the preparation of the catalyst component. To derive the magnesium compounds (a-2) without reducing ability from the magnesium compounds (a-1) with reducing ability, for example, the magnesium compounds (a-1) with 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.

[0018] Furthermore, in the present invention, the compound (a-2) having no reducing ability can be derived from the magnesium compound (a-1) having reducing ability using an organosilicon compound (c) having no active hydrogen, as described below. Two or more magnesium compounds can also be used in combination.

[0019] 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.

[0020] 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.

[0021] Among the above compounds, magnesium compounds 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.

[0022] In the present invention, when the magnesium compound is solid, it can be liquefied using an electron donor (d-1). Examples of such electron donors (d-1) include alcohols, carboxylic acids, aldehydes, amines, and 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.

[0023] 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.

[0024] 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, which are described below as organosilicon compounds (c) that do not have active hydrogen. Two or more of these compounds can be used in combination, and electron donors (d) other than those described below can also be used in combination. Among these compounds, alcohols and metal acid esters are preferred, and alcohols having 6 or more carbon atoms are particularly preferred.

[0025] When a magnesium compound is liquefied using the electron donor (d-1) described above, if an electron donor having 6 or more carbon atoms is used as the electron donor (d-1), it is usually used in an amount of about 1 mol or more, preferably 1 to 40 mol, more preferably 1.5 to 12 mol, per mol of the magnesium compound. If an electron donor having 5 or less carbon atoms is used, it is usually necessary to use about 15 mol or more per mol of the magnesium compound.

[0026] A hydrocarbon solvent can be used when contacting the solid magnesium compound with the electron donor (d-1). Examples of such a hydrocarbon solvent 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.

[0027] When using aromatic hydrocarbons among such solvents, alcohols as the electron donor (d-1) can dissolve the magnesium compound if used in the amount shown as the usage amount of the above electron donor having 6 or more carbon atoms regardless of their type (number of carbon atoms). When using aliphatic hydrocarbons and / or alicyclic hydrocarbons, alcohols as the electron donor (d-1) are used in an amount corresponding to the number of carbon atoms as described above.

[0028] In the present invention, it is preferable to contact the solid magnesium compound with the electron donor (d-1) in a hydrocarbon solvent. To dissolve the solid magnesium compound in the electron donor (d-1), a method of preferably contacting the solid magnesium compound with the electron donor (d-1) in the coexistence of a hydrocarbon solvent and heating as necessary is common. 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 5 hours, preferably about 30 minutes to 4 hours.

[0029] <(c) Organosilicon compound having no active hydrogen> The organosilicon compound having no active hydrogen used in the present invention is, for example, R 1 xR 2 ySi(OR 3 )z (R 1 , R 2 are each independently a hydrocarbon group or a halogen, and R 3 is a hydrocarbon group, and 0 ≤ x < 2, 0 ≤ y < 2, 0 < z ≤ 4.) is represented.

[0030] 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, methyltriallyloxysilane, 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.

[0031] Among these, tetramethoxysilane, tetraethoxysilane, cyclohexylmethyldimethoxysilane, etc. are preferably used, with tetraethoxysilane being particularly preferred from the standpoint of catalytic activity.

[0032] In the above-described embodiment, it is sufficient that the organosilicon compound (c) having no active hydrogen is contained in the finally obtained solid titanium catalyst component. Therefore, when preparing the solid titanium catalyst component, it is not necessary to use the above-described organosilicon compound (c) having no active hydrogen itself, and other compounds capable of generating an organosilicon compound having no active hydrogen in the process of preparing the solid titanium catalyst component can also be used.

[0033] The active hydrogen-free organosilicon compound (c) of the present invention is preferably used in an amount of 0.25 to 0.35 mol per mol of the liquid magnesium compound (a). The lower limit is more preferably 0.26 mol, and even more preferably 0.27 mol. Meanwhile, the upper limit is more preferably 0.34 mol, and even more preferably 0.33 mol.

[0034] <(b) Liquid titanium compound> The present invention is characterized in that a liquid halogen-containing titanium compound specified by the following structural formula (1) is used as the liquid titanium compound. (R 11 -CR 12 2-O) β -Ti-X γ ···(1) (R 11 is a group selected from a hydrogen atom and a hydrocarbon group having 1 to 5 carbon atoms, R 12 is a group selected from a hydrogen atom and a hydrocarbon group having 1 to 2 carbon atoms, R 11 , R 12 When both are hydrocarbon groups, (R 11 (number of carbon atoms in R 12 (number of carbon atoms) R 11 and R 12 The total number of carbon atoms is 7 or less. X is a halogen atom, β and γ are positive real numbers, 2≦β+γ≦4)

[0035] The above R 11 Specific examples of R include a hydrogen atom, a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, a 2-butyl group, an isobutyl group, an n-pentyl group, an isopentyl group, and a 2-pentyl group. 11 The hydrocarbon group R is preferably a straight-chain hydrocarbon group. It may also be an alkenyl group or alkynyl group having an unsaturated structure corresponding to the above. Of these, a straight-chain alkyl group is preferred. 11may be an embodiment containing a heteroatom. Such a heteroatom is preferably an atom selected from oxygen, nitrogen, and silicon, more preferably oxygen and silicon. Specific examples include an alkoxy group and an alkoxysilyl group.

[0036] The above R 12 Specific examples of R include a hydrogen atom, a methyl group, and an ethyl group. Examples of R containing a heteroatom include a methoxy group, an ethoxy group, and an ethoxysilyl group. 12 is a hydrogen atom or a methyl group, and in particular is a hydrogen atom. 12 may be the same or different.

[0037] In the present invention, R 11 , R 12 When both are hydrocarbon groups, (R 11 (number of carbon atoms in R 12 (number of carbon atoms in R 11 -CR 12 2-O) as a single substituent, R 11 The chain structure containing R 12 It corresponds to a structure longer than the chain structure containing the above. Furthermore, the length of the long chain, that is, the main chain, is preferably a structure having an even number of carbon atoms (e.g., ethoxy, n-butoxy, n-hexoxy).

[0038] Above R 11 and R 12 The total number of carbon atoms in each of the groups is 7 or less. A more preferred lower limit is 2. On the other hand, a more preferred upper limit is 6, even more preferably 5, and particularly preferably 4. Representative examples of the halogen atom of X include fluorine, chlorine, bromine, and iodine, of which chlorine and bromine are preferred, with chlorine being the most preferred.

[0039] The β and γ are positive real numbers and satisfy the relationship 2≦β+γ≦4. The value of β+γ preferably matches the valence number or oxidation number of titanium. More specifically, β is preferably 2 or less, more preferably 1.5 or less. γ is preferably 2 or more, more preferably 2.5 or more.

[0040] Among the above, tetravalent titanium compounds are particularly preferred. Examples of such tetravalent titanium compounds include compounds represented by the following formula:

[0041] Specific examples of such compounds include trihalides such as Ti(O-ethyl)Cl3, Ti(On-propyl)Cl3, Ti(O-isopropyl)Cl3, Ti(On-butyl)Cl3, Ti(O-2-butyl)Cl3, Ti(O-isobutyl)Cl3, Ti(On-hexyl)Cl3, Ti(O-ethyl)Br3, Ti(On-propyl)Br3, Ti(O-isopropyl)Br3, Ti(On-butyl)Br3, Ti(O-2-butyl)Br3, Ti(O-isobutyl)Br3, and Ti(On-hexyl)Br3. Examples of suitable titanium compounds include titanium halides, dihalogenated dialkoxytitanium compounds such as Ti(O-ethyl)2Cl2, Ti(O-butyl)2Cl2, Ti(O-hexyl)2Cl2, Ti(O-ethyl)2Br2, Ti(O-butyl)2Br2, and Ti(O-hexyl)Br3, and monohalogenated trialkoxytitanium compounds such as Ti(O-ethyl)3Cl, Ti(O-butyl)3Cl, Ti(O-hexyl)3Cl, Ti(O-ethyl)3Br, Ti(O-butyl)3Br, and Ti(O-hexyl)3Br. Among these, titanium trihalides are preferred, with Ti(O-ethyl)Cl3, Ti(O-propyl)Cl3, Ti(O-butyl)Cl3, and Ti(O-hexyl)Cl3 being preferred. These titanium compounds can also be used in combination with two or more of them. They may also be used by diluting them in a hydrocarbon solvent, as described in (a) for liquefying the magnesium compound.

[0042] The above-mentioned titanium compound (b) can also be obtained by reacting a titanium halide such as titanium tetrachloride or titanium tetrabromide or an alkoxytitanium halide with the corresponding alcohol, alkoxyalcohol, or alkoxysilane compound. It is well known that in such reactions, a halogen reacts with the OH group of the alcohol to produce an alkoxytitanium compound. In the examples of the present invention described below, an alkoxytitanium compound is prepared by contacting and reacting titanium tetrachloride with an alcohol at a low temperature in advance. It is also known that, in general, the reaction of a titanium halide compound with an alcohol tends to preferentially produce a monoalkoxide first.

[0043] Examples of alcohols that can be used in such reactions include methanol, ethanol, n-propanol, isopropanol, n-butanol, 2-butanol, isobutanol, n-pentanol, isopentanol, 2-pentanol, n-hexanol, isohexanol, etc. Other specific examples of the compounds include corresponding alkoxysilane compounds.

[0044] The halogen-containing titanium compound (b) used in the present invention can also be used in a state containing a titanium compound (x) other than those mentioned above. Such titanium compound (x) is, for example, a titanium compound represented by the following formula: Ti(OR) g X 4-g In the formula, R is a hydrocarbon group, X is a halogen atom, and 0≦g≦4. R is a hydrocarbon group having 8 or more carbon atoms.

[0045] Specific examples of such compounds include titanium tetrahalides such as TiCl, TiBr, and TiI; alkoxytitanium trihalides such as Ti(O-2-ethylhexyl)Cl and Ti(O-2-ethylhexyl)Br; dialkoxytitanium dihalides such as Ti(O-2-ethylhexyl)Cl and Ti(O-2-ethylhexyl)Br; trialkoxytitanium monohalides such as Ti(O-2-ethylhexyl)Cl and Ti(O-2-ethylhexyl)Br; and tetraalkoxytitanium such as Ti(O-2-ethylhexyl)4. Among these, titanium tetrahalides, Ti(O-2-ethylhexyl)Cl, and Ti(O-2-ethylhexyl)Br are preferred, with titanium tetrachloride and Ti(O-2-ethylhexyl)Cl being particularly preferred. These titanium compounds can also be used in combination. Furthermore, they may be diluted with a hydrocarbon solvent, as described in (a) for liquefying the magnesium compound.

[0046] The halogen-containing titanium compound (b) of the present invention is prepared in advance before contacting with the liquid magnesium compound (a), and does not include, for example, a method in which the alcohol-containing magnesium compound is contacted with titanium tetrachloride (an embodiment in which an alkoxytitanium compound is formed during this reaction).

[0047] When the halogen-containing titanium compound (b) of the present invention is used in combination with another titanium compound (x), the halogen-containing titanium compound (b) preferably accounts for 0.1 mol % to 95 mol %, with the titanium atoms of all compounds being 100 mol %. A more preferred lower limit is 0.5 mol %, even more preferably 1 mol %, and particularly preferably 1 mol %. On the other hand, a more preferred upper limit is 50 mol %, even more preferably 30 mol %, particularly preferably 10 mol %, and particularly preferably 7 mol %.

[0048] <(d) Other electron donors> In the present invention, when preparing the solid titanium catalyst component, it is preferable to use the above-mentioned organosilicon compound (c) which does not have active hydrogen, but other electron donors (d) which do not have active hydrogen can also be used.

[0049] In the present invention, examples of such other electron donors (d) include organic acid esters, organic acid halides, organic acid anhydrides, ethers, ketones, tertiary amines, phosphites, phosphates, carboxylic acid amides, nitriles, aliphatic carbonates, pyridines, etc. More specifically, 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, etc. organic acid esters having 2 to 18 carbon atoms, such as benzoyl, phenyl benzoate, benzyl benzoate, methyl toluate, ethyl toluate, amyl toluate, ethyl ethylbenzoate, methyl anisate, ethyl anisate, and ethyl ethoxybenzoate; acid halides having 2 to 15 carbon atoms, such as acetyl chloride, benzoyl chloride, and toluic acid chloride; acid anhydrides, such as acetic anhydride, phthalic anhydride, maleic anhydride, benzoic anhydride, trimellitic anhydride, and tetrahydrophthalic anhydride; methyl ethers; Ethers having 2 to 20 carbon atoms, such as ethyl ether, isopropyl ether, butyl ether, amyl ether, tetrahydrofuran, ethyl benzyl ether, ethylene glycol dibutyl ether, anisole, and diphenyl ether; ketones having 3 to 20 carbon atoms, such as acetone, methyl ethyl ketone, methyl isobutyl ketone, 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; N,N-dimethylamide acetate; N-benzoate;Examples of suitable compounds include acid amides such as 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. Two or more of these compounds can also be used in combination.

[0050] <(A) Preparation of solid titanium catalyst component> Specific methods for using the above-mentioned components in the present invention are described below. Specifically, a preferred example is to prepare the solid titanium catalyst component (A) by the following method. (1) (a) A liquid magnesium compound is contacted with (b) a liquid titanium compound in the presence of (c) an organosilicon compound having no active hydrogen (hereinafter simply referred to as "organosilicon compound (c)") in an amount of 0.25 to 0.35 moles per mole of the magnesium compound (a), and the resulting contact product (i) is heated to a temperature within a range of 105 to 115°C and maintained at this temperature. (2) In the process of heating the contact product (i) and maintaining it at a temperature within the range of 105 to 115°C as described above, an organosilicon compound (c) is added in an amount of 0.5 moles or less per mole of the magnesium compound (a) and contacted with the contact product (i) during the period from a temperature 10°C lower than the maintaining temperature to the end of the temperature rise or after the end of the temperature rise. In the present invention, among the above methods, method (2) may be preferable in terms of the catalytic activity of the resulting solid titanium catalyst component.

[0051] In the present invention, when the components are contacted, the organosilicon compound (c) is preferably used in the amount specified above relative to the magnesium compound (a). The titanium compound (b) is preferably used in a sufficient amount to precipitate a solid product upon contact without the need for special precipitation means. The amount of titanium compound (b) used will vary depending on the type, contact conditions, and amount of organosilicon compound (c) used, but is typically preferably about 1 mole or more relative to 1 mole of magnesium compound (a), more preferably about 5 to about 200 moles, and particularly preferably about 10 to about 100 moles. The titanium compound (b) is preferably used in an amount greater than 1 mole relative to 1 mole of organosilicon compound (c), more preferably 5 moles or more.

[0052] Each of the above contact methods will be explained in more detail. The liquid magnesium compound (a) and / or titanium compound (b) used in the contact of the liquid magnesium compound (a) with the titanium compound (b) may already contain an organosilicon compound (c). In this case, it is not necessary to add the organosilicon compound (c) when the magnesium compound (a) and the titanium compound (b) are contacted, but it may be added. In either case, the total amount of the organosilicon compound (c) relative to the magnesium compound (a) should be within the above range.

[0053] In the present invention, the contact of the liquid magnesium compound (a) with the liquid titanium compound (b) in the presence of the organosilicon compound (c) is preferably carried out at a low temperature so that a solid product is not rapidly formed by this contact, specifically at a temperature of -70 to +50°C, preferably -50 to +30°C, and more preferably -40 to +20°C. The temperatures of the solutions used in the contact may be different. If the contact temperature is too low at the beginning of the contact and a solid product does not precipitate in the contact product (i), the contact can be carried out at a low temperature for a long period of time to precipitate a solid product.

[0054] In the present invention, the contact product (i) obtained above is then gradually heated to a temperature within a range of 105 to 115°C to gradually precipitate a solid, and this temperature is maintained. The maintenance time is usually 0.5 to 6 hours, preferably about 1 to 4 hours. The time required for heating varies greatly depending on the scale of the reactor, etc.

[0055] Under these conditions, when the liquid magnesium compound (a) is contacted with the liquid titanium compound (b) in the presence of the organosilicon compound (c) that does not have active hydrogen, granular or spherical solid particles having a relatively large particle size and a good particle size distribution can be obtained.

[0056] In a preferred method of the present invention, the solid particles are filtered off, followed by contact with the liquid titanium compound (b) for a second time to obtain a solid titanium catalyst component. The filtration and contact steps with the liquid titanium compound (b) can be repeated as long as they achieve the objectives of the present invention. In the second and subsequent contact steps between the liquid titanium compound (b) and the solid component, the titanium content in the solid titanium catalyst component does not change significantly, but the ORa group content tends to decrease relatively easily. Therefore, this is an effective means for adjusting the titanium to ORa group ratio. The effectiveness of this method of contacting the liquid titanium compound (b) two or more times is not limited to the method described in Patent Document 1. It can also be applied to known methods for producing solid olefin polymerization catalysts, such as the method for producing a solid titanium catalyst component containing an alicyclic dicarboxylic acid ester disclosed in International Patent Publication No. 09 / 125729.

[0057] When ethylene or an olefin having 3 or more carbon atoms is polymerized by a method such as slurry polymerization using the solid titanium catalyst component thus obtained, which preferably has excellent particle properties, an ethylene polymer satisfying the requirements described below can be produced.

[0058] In the contact method (2), in the above-described method (1), the contact product (i) is heated to a temperature in the range of 105 to 115°C and maintained at this temperature for usually 0.5 to 6 hours, preferably 1 to 4 hours. During this process, an organosilicon compound (c) is added in an amount of 0.5 moles or less per mole of the magnesium compound (a) and contacted with the contact product (i) either during the period from a temperature 10°C lower than the maintained temperature to the end of the temperature increase or after the end of the temperature increase (preferably immediately after).

[0059] The solid titanium catalyst component according to the present invention, prepared as described above, contains magnesium, titanium, a halogen, and (c) an organosilicon compound having no active hydrogen. In this solid titanium catalyst component, the magnesium / titanium (atomic ratio) is about 2 to about 100, preferably about 4 to about 50, and more preferably about 5 to about 30; the halogen / titanium (atomic ratio) is about 4 to about 100, preferably about 5 to about 90, and more preferably about 8 to about 50; and the organosilicon compound (c) / titanium (molar ratio) is about 0.01 to about 100, preferably about 0.2 to about 10, and more preferably about 0.4 to about 6. The organosilicon compound (c) / magnesium (molar ratio) is about 0.001 to about 0.1, preferably about 0.002 to about 0.08, and particularly preferably 0.005 to 0.05.

[0060] The solid titanium catalyst component 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 weight or less, preferably 40% by weight or less, more preferably 30% by weight or less, and even more preferably 20% by weight 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.

[0061] The shape of the solid titanium catalyst component according to the present invention is preferably granular or approximately spherical, and its specific surface area is about 10 m 2 / g or more, preferably about 100 to 1000m 2In the present invention, the solid titanium catalyst component is usually washed with a hydrocarbon solvent before use.

[0062] The solid titanium catalyst component (A) of the present invention has a magnesium content of 10 to 25 mass %, The titanium content is preferably 3 to 12 mass %.

[0063] The lower limit of the magnesium content is preferably 12 mass%, more preferably 13 mass%, and even more preferably 14 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 is preferably 4 mass %, more preferably 5 mass %, while the upper limit is preferably 11 mass %, more preferably 10 mass %, and even more preferably 9 mass %.

[0064] Within the above range, olefins including ethylene can be polymerized with high activity, and olefin polymers with a relatively low molecular weight (high MFR) relative to the amount of hydrogen used can be obtained with high activity. Furthermore, olefin polymers with a broad molecular weight distribution, as indicated by Mz / Mw or Mw / Mn, tend to be obtained. Specifically, Mz / Mw is preferably 8 or more, more preferably 10 or more, and even more preferably 12 or more. While there is no particular upper limit, taking into consideration the surface and outer appearance of the polymer when it is melt-molded, it is preferably 30 or less, more preferably 20 or less, and even more preferably 17 or less.

[0065] On the other hand, Mw / Mn is preferably 7 or more, more preferably 8 or more, and even more preferably 9 or more. On the other hand, the upper limit is preferably 20, more preferably 17, and even more preferably 15.

[0066] <Olefin polymerization catalyst> The olefin polymerization catalyst according to the present invention is formed from the above-mentioned (A) solid titanium catalyst component and (B) organometallic compound.

[0067] The organometallic compound (B) used in the present invention preferably contains a metal selected from Groups 1 and 2 to 13 of the periodic table, and specific examples thereof include organoaluminum compounds, alkyl complex compounds of Group 1 metals with aluminum, and organometallic compounds of Group 2 metals.

[0068] Examples of such organoaluminum compounds include those represented by the following formula: R α n AlX 3-n (In the formula, R α is a hydrocarbon group having 1 to 12 carbon atoms, X is a halogen or hydrogen, and n is 1 to 3.

[0069] R αis a hydrocarbon group having 1 to 12 carbon atoms, such as an alkyl group, a cycloalkyl group, or an aryl group, and specific examples thereof 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, and a tolyl group. Specific examples of such 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 diethylaluminum hydride and diisobutylaluminum hydride.

[0070] As the organoaluminum compound, a compound represented by the following formula can also be used. R α n AlY 3-n In the above formula, R α is the same as above, and Y is -OR β 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 β , 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.

[0071] Specific examples of such organoaluminum compounds include the following compounds: (i)R α n Al(OR β ) 3-n Dimethylaluminum methoxide, diethylaluminum ethoxide, diisobutylaluminum methoxide, etc. (ii)R α n Al(OSiR c 3) 3-n Et2Al(OSiMe3), (iso-Bu)2Al(OSiMe3), (iso-Bu)2Al(OSiEt3), etc. (iii)R α n Al(OAlR d 2) 3-n Et2AlOAlEt2, (iso-Bu)2AlOAl(iso-Bu)2, etc. (iv)R α n Al(NR e 2) 3-n Me2AlNEt2, Et2AlNHMe, Me2AlNHEt, Et2AlN(Me3Si)2, (iso-Bu)2AlN(Me3Si)2, etc. (v)R α n Al(SiR f 3) 3-n (iso-Bu)2AlSiMe3, etc. (vi)R α n Al〔N(Rg )-AlR h 2) 3-n Et2AlN(Me)-AlEt2 (iso-Bu)2AlN(Et)Al(iso-Bu)2 etc.

[0072] Other examples include similar compounds, such as organoaluminum compounds in which two or more aluminum atoms are bonded via oxygen or nitrogen atoms. More specifically, examples include (C2H5)2AlOAl(C2H5)2, (C4H9)2AlOAl(C4H9)2, (C2H5)2AlN(C2H5)Al(C2H5)2, and aluminoxanes such as methylaluminoxane.

[0073] Examples of alkylated complexes of Group 1 metals and aluminum include compounds represented by the following general formula: M 1 AlR j 4 (M 1 are Li, Na, and K, and R j is a hydrocarbon group having 1 to 15 carbon atoms. Specific examples of such compounds include LiAl(C2H5)4, LiAl(C7H 15 )4 etc.

[0074] Examples of organometallic compounds of Group 2 metals include 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.) Specific examples include diethyl zinc, diethyl magnesium, butylethyl magnesium, ethyl magnesium chloride, and butyl magnesium chloride.

[0075] Among the above organoaluminum compounds, R α n AlX 3-n , R α n Al(OR β ) 3-n , R α n Al(OAlR d 2) 3-n The compounds represented by the formula (I), particularly trialkylaluminum, are preferably used. Two or more of these compounds can also be used in combination. In the olefin polymerization catalyst according to the present invention, for example, the ethylene polymerization catalyst, olefins may be prepolymerized. The olefin polymerization catalyst according to the present invention may contain other components useful for ethylene polymerization in addition to the above-mentioned components.

[0076] <Olefin polymerization method> In the method for polymerizing olefins such as ethylene (main polymerization) according to the present invention, olefins are polymerized in the presence of an olefin polymerization catalyst comprising (A) a solid titanium catalyst component and (B) an organometallic compound as described above. Specifically, an embodiment including a step of copolymerizing ethylene with an olefin having 3 or more carbon atoms may be preferable.

[0077] Specific examples of the olefins having 3 or more carbon atoms include α-olefins having 3 to 20 carbon atoms, such as propylene, 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.

[0078] Two or more of the above-mentioned olefins having 3 or more carbon atoms can also be copolymerized with ethylene. In the present invention, in the polymerization of ethylene, the (A) solid titanium catalyst component (or prepolymerized catalyst) 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 (B) organometallic compound is preferably used in an amount such that the metal atoms in the catalyst component are usually about 1 to 2,000 moles, preferably about 5 to 500 moles, per mole of titanium atoms in the (A) solid titanium catalyst component in the polymerization system.

[0079] 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, an olefin or the like that is liquid at the reaction temperature may also be used together with the organic solvent.

[0080] The polymerization conditions vary depending on the type of polymerization or the type of olefin polymer, for example, ethylene polymer, 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.

[0081] 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.

[0082] In the present invention, the catalyst is formed using the specific solid titanium catalyst component (A) described above when polymerizing olefins, which allows the production of specific olefin polymers as described below with extremely high polymerization activity. Therefore, the resulting olefin polymers, such as ethylene polymers, have a low catalyst content, particularly a low halogen content, per polymer unit, and are less likely to rust during molding. Furthermore, the resulting olefin polymers, such as ethylene polymers, have a low fine powder content and excellent particle properties, so they may be used without pelletizing.

[0083] (olefin polymer) When the solid titanium catalyst of the present invention is used in a method for producing an olefin polymer, any known method can be used without any limitation. The olefin polymer to be produced is also not particularly limited. Preferred examples include polymers that satisfy the following requirements: (PE1) the content of ethylene-derived structural units is 90 mol% or more and 99.5 mol% or less; (PE2) The content of structural units derived from olefins having 3 to 20 carbon atoms is 0.5 mol % or more and 10 mol % or less (provided that the total of PE1 and PE2 is 100 mol %). (D) Density is 900 to 960 kg / m 3

[0084] The lower limit of the content of structural units derived from ethylene (PE1) is preferably 93 mol%, more preferably 95 mol%, and even more preferably 97 mol%, while the upper limit is preferably 99.0 mol%, more preferably 98.5 mol%, and even more preferably 98.0 mol%. The lower limit of the content of structural units derived from olefins having 3 to 20 carbon atoms (PE2) is preferably 1.0 mol%, more preferably 1.5 mol%, and even more preferably 2.0 mol%, while the upper limit is preferably 7 mol%, more preferably 5 mol%, and even more preferably 3 mol%.

[0085] The content of the above olefin-derived structural units is 13NMR measurement is performed using a CNMR device, and peaks characteristic of the corresponding olefins are assigned in the usual 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 olefin-derived structural units can also be determined by IR measurement.

[0086] (D) The preferred lower limit of the density of the olefin polymer of the present invention is 910 kg / m 3 , more preferably 920 kg / m 3 , and more preferably 930 kg / m 3 On the other hand, the preferred upper limit is 955 kg / m 3 An olefin polymer having such a density, or a so-called olefin polymer composition containing such an olefin polymer, is excellent in impact resistance, toughness, environmental resistance (for example, environmental stress cracking resistance (ESCR)), and is suitable as a raw polymer for packaging materials, containers, etc. The density of the olefin polymer of the present invention is determined using a density gradient tube in accordance with the method described in JIS K 6922 standard.

[0087] Other preferred physical properties of the olefin polymer obtained in the present invention can be exemplified as follows. The bulk density is desirably 0.20 to 0.60 g / cc, preferably 0.25 to 0.60 g / cc. The melt flow rate MFR (based on ASTM D1238E, 2.16 kg load, 190° C.) is desirably 0.01 to 130 g / 10 min, preferably 0.01 to 100 g / 10 min. The intrinsic viscosity [η] measured in decalin at 135° C. (according to JIS K 7367-3 standard) is preferably 1.5 to 10 dl / g, more preferably 2.0 to 8 dl / g.

[0088] When the solid titanium catalyst component (A) obtained by the production method of the present invention is used to polymerize olefins, particularly olefins mainly composed of ethylene, it tends to be possible to produce olefin polymers having relatively low molecular weights with high polymerization activity. Furthermore, it also tends to be easy to obtain polymers having a broad molecular weight distribution. The reason for this effect is currently unknown, but the present inventors speculate as follows.

[0089] In the present invention, a solid titanium catalyst component is produced by contacting a liquid titanium compound (b) (titanium compound containing) having a specific alkoxy group-like structure, such as a halogen-containing titanium alkoxide, with a liquid magnesium compound. Since the titanium compound containing the specific alkoxy group or other substituent group coexists with the magnesium compound (a) from the stage when the magnesium compound (a) changes into a solid state, the titanium compound (b) will be in a favorable positional relationship with the magnesium compound (a) and will form a solid compound in a form having strong interaction with the magnesium compound (a).

[0090] Furthermore, since the substituent has an oxygen-containing structure, it is thought that it easily donates electrons to titanium, forming a particularly relatively stable polymerization active species. Such active species are likely to exhibit high activity in the polymerization reaction of olefins with relatively low electron density (e.g., ethylene) and in hydrogen chain transfer reactions. On the other hand, since the substituent is relatively small and therefore mobile, the performance of the active species is relatively susceptible to change (fluctuation), which may tend to make it easier to obtain olefin polymers with a wider molecular weight distribution than conventional methods.

[0091] However, the scope of the solid titanium catalyst component of the present invention is not limited by the above hypothesis.

[0092] The olefin polymer, for example, ethylene polymer, 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. Within the above-mentioned range, it can be suitably used as a raw material polymer for films, containers, etc. It is particularly suitable as a raw material polymer for containers obtained from blow molded articles, etc.

Examples

[0093] Next, the present invention will be specifically described by way of examples, but the present invention is not limited to these examples. In the following examples, the composition of the solid titanium catalyst component, the MFR of the ethylene polymer, and various average molecular weights were measured as follows.

[0094] (1) Mg, Ti, Si contents Using an ICP analyzer (Shimadzu Corporation, ICPF 1000TR), the solid titanium catalyst component and the obtained polymer were measured and determined by a conventional method. Also, from these results, the polymerization activity was determined by a conventional method.

[0095] (2) OR group content A sufficiently dried catalyst was added to an acetone solution containing 10% by weight of water, hydrolyzed, and the ROH obtained was quantified by gas chromatography under the following conditions. Device manufacturer: Shimadzu Corporation Device model number: GC-2010Plus Column manufacturer: Agilent J&W Column part number, specifications: DB-Wax length 30m inner diameter 0.250mm film thickness 0.50μm

[0096] (3) MFR The MFR of the ethylene polymer was measured under the conditions of 190℃ and a load of 2.16 kg in accordance with ASTM D1238E.

[0097] (4) Various average molecular weights <GPC measurement> Device: Gel permeation chromatograph HLC-8321 GPC / HT type (manufactured by Tosoh Corporation) Detector: Differential refractometer (built-in in the device) TSKgel GMH6-HT x 2 + TSKgel GMH6-HTL x 2 (both 7.5mm I.D. x 30cm, Tosoh Corporation) Column temperature: 140℃ Mobile phase: o-dichlorobenzene (ODCB) with BHT Flow rate: 1.0mL / min Sample concentration: 20 mg / 20 mL (1.0 mg / mL) Melting conditions: 145℃, 120min Sample filtration: 1.0 μm sintered filter Injection volume: 0.4mL Column calibration: Monodisperse polystyrene (TSKgel standard polystyrene; Tosoh)

[0098] Example 1 4.76 g (50 mmol) of anhydrous magnesium chloride, 28.1 ml of decane, and 16.3 g (125 mmol) of 2-ethylhexyl alcohol were heated and reacted at 130°C for 3 hours to form a homogeneous solution, and then 3.1 g (15 mmol) of tetraethoxysilane was added to this solution, followed by stirring and mixing at 50°C for an additional 2 hours to dissolve the tetraethoxysilane in the solution, which was then slowly cooled to room temperature to obtain a liquid magnesium compound containing an alkoxysilane compound.

[0099] On the other hand, 50 mmol of ethanol was gradually added to 200 ml (1.8 mol) of titanium tetrachloride kept at 0° C. while stirring, to prepare a liquid halogen-containing titanium compound. The liquid magnesium compound was added dropwise over one hour to the liquid halogen-containing titanium compound at 0° C. while stirring it. After the addition was completed, the temperature of this mixture was maintained at 0° C. for one hour, then heated to 110° C. over one hour and 45 minutes, and then maintained at the same temperature for two hours with stirring.

[0100] After the 2-hour reaction was completed, the solid portion was separated by hot filtration and washed with decane at 110°C and hexane at room temperature. It was confirmed that no free titanium compounds were detected in the washings. The solid titanium catalyst component thus obtained was collected as a hexane suspension. The composition of the solid titanium catalyst component obtained is shown in Table 1.

[0101] "polymerization" A 1-liter autoclave was charged with 500 ml of purified n-heptane under a nitrogen atmosphere, and 0.25 mmol of triethylaluminum and the hexane suspension of the solid titanium catalyst component obtained above in an amount equivalent to 0.015 mmol of titanium atom were added. The temperature was then raised to 80°C, hydrogen was fed at 0.50 MPaG, and ethylene was then continuously fed for 1.5 hours so that the total pressure became 0.60 MPaG. The polymerization temperature was maintained at 80°C.

[0102] Examples 2 to 5 A solid titanium catalyst component was obtained in the same manner as in Example 1, except that the ethanol was replaced with the compound shown in Table 1. The composition of the obtained solid titanium catalyst component is shown in Table 1. "polymerization" Polymerization was carried out in the same manner as in Example 1, except that the solid titanium catalyst component shown in Table 1 was used. The results are shown in Table 2.

[0103] (Comparative Example 1) Preparation of a solid titanium catalyst component and polymerization were carried out in the same manner as in Example 1, except that titanium tetrachloride alone was used as the liquid titanium compound. The results are summarized in Tables 1 and 2.

[0104] [Table 1]

[0105] [Table 2]

Claims

1. (a) a liquid magnesium compound; (c) an organosilicon compound having no active hydrogen; (b) contacting a liquid halogen-containing titanium compound satisfying the following formula (1): A method for producing a solid titanium catalyst component containing magnesium, titanium, and a halogen, comprising the steps of heating the obtained contact product (i) to a temperature in the range of 105 to 115°C and maintaining the temperature. (R 11 -CR 12 2 -O) β -Ti-X γ ・・・(1) (R 11 is a group selected from a hydrogen atom and a hydrocarbon group having 1 to 5 carbon atoms, R 12 is a group selected from a hydrogen atom and a hydrocarbon group having 1 to 2 carbon atoms, R 11 , R 12 When both are hydrocarbon groups, R 11 Number of carbon atoms in ≧R 12 is the number of carbon atoms, R 11 and R 12 and the total number of carbon atoms is 7 or less, X is a halogen atom; β and γ are positive real numbers, and 2≦β+γ≦4)

2. (a) per mole of the liquid magnesium compound, 2. The method for producing a solid titanium catalyst component according to claim 1, wherein (c) the organosilicon compound having no active hydrogen is used in an amount of 0.25 to 0.35 moles.

3. 2. The method for producing a solid titanium catalyst component according to claim 1, wherein β is 1.5 or less.

4. 2. The method for producing a solid titanium catalyst component according to claim 1, wherein (b) the liquid halogen-containing titanium compound is a reaction product of a titanium halide and an alcohol compound.

5. A method for producing an ethylene polymer, comprising polymerizing olefins including ethylene in the presence of an ethylene polymerization catalyst comprising the solid titanium catalyst component (A) obtained by the method according to any one of claims 1 to 4 and an organometallic compound (B).

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