Method for producing propylene polymer

The present invention relates to a method for producing a propylene-based polymer.

A propylene-based polymer having a crystalline propylene-based polymer portion and an amorphous propylene-based polymer portion is excellent in heat resistance, rigidity, and impact resistance. Therefore, automobile parts such as bumpers and door trims, retort food packaging containers, etc. It is used in various packaging containers. As a method for producing the propylene-based polymer, for example, polypropylene particles are obtained by polymerizing propylene by a slurry polymerization method in the first-stage polymerization step, and then the polypropylene particles are used in the second-stage polymerization step. , A method of copolymerizing propylene and ethylene to obtain polymer particles by a vapor phase polymerization method has been proposed (see, for example, Patent Document 1).

<patcit num="1"><text>Japanese Unexamined Patent Publication No. 10-168142</text></patcit>

<p> However, in the above method, the adhesiveness of the polymer particles is increased, the mixed state of the polymer particles in the polymerization reactor becomes non-uniform, and when the polymer particles are extracted from the polymerization reactor, the extraction port is provided. There was a blockage. Under such circumstances, the problem to be solved by the present invention is a method for producing a propylene-based polymer having a crystalline propylene-based polymer portion and an amorphous propylene-based polymer portion, and the adhesiveness is reduced. It is an object of the present invention to provide a method for producing a propylene-based polymer capable of obtaining the resulting polymer particles.</p>

<p> The present invention is a method for producing a propylene-based polymer having the following steps (I), steps (II) and steps (III), and has steps (II) and steps (III) after step (I). , The content of the following polymer component (A) in the propylene-based polymer is 55 to 85% by weight, the content of the following polymer component (B) is 5 to 15% by weight, and the following polymer component ( The content of C) is 10 to 30% by weight (however, the propylene-based polymer is 100% by weight). Step (I): A polymer component having a propylene-based monomer unit content of 96% by weight or more (however, the content of all monomer units of the polymer component is 100% by weight). Process for producing A) Step (II): The content of the monomer unit based on propylene is 65 to 90% by weight (however, the content of all the monomer units of the polymer component is 100% by weight. ) And a step of producing the polymer component (B) having an ultimate viscosity ([η] b) of 1 to 3 dl / g (III): Content of monomer unit based on propylene is 30 to 60 weight by weight. % (However, the content of all monomer units of the polymer component is 100% by weight), the ultimate viscosity ([η] c) is 1.5 to 9 dl / g, and the [η] c. A step of producing a polymer component (C) in which is larger than [η] b</p>

<p> INDUSTRIAL APPLICABILITY According to the present invention, a method for producing a propylene-based polymer having a crystalline propylene-based polymer portion and an amorphous propylene-based polymer portion, wherein polymer particles having reduced adhesiveness can be obtained. A method for producing a coalescence can be provided.</p>

In step (I), the polymer component having a propylene-based monomer unit content of 96% by weight or more (however, the content of all the monomer units of the polymer component is 100% by weight). This is the process of manufacturing (A). If the value is too small, the adhesive resistance of the polymer particles may be inferior, and the heat resistance of the propylene-based polymer may be lowered. The content of the monomer unit based on propylene is measured by infrared spectroscopy.

In step (I), propylene may be homopolymerized, or a monomer other than propylene may be copolymerized with propylene. Examples of the monomer other than propylene include olefins having 2 to 8 carbon atoms (excluding propylene) such as ethylene, 1-butene, 1-hexene, and 1-octene. , 1 type or a combination of 2 or more types. The polymer component produced in the step (I) is preferably a propylene homopolymer and a propylene-ethylene copolymer.

Examples of the polymerization method in step (I) include a bulk polymerization method, a solution polymerization method, a slurry polymerization method and a gas phase polymerization method. The bulk polymerization method is a method of polymerizing using a liquid olefin as a medium, and the solution polymerization method or the slurry polymerization method is an inert carbonization of propane, butane, isobutane, pentane, hexane, heptane, octane and the like. This is a method of polymerizing in a hydrogen solvent. The gas phase polymerization method is a method of polymerizing a gaseous monomer in the medium using a gaseous monomer as a medium. These polymerization methods may be arbitrarily combined, and these polymerization methods may be batch type, semi-batch type, or continuous type. Further, in the step (I), the polymerization temperature is usually 0 to 120 ° C, preferably 20 to 100 ° C, and the polymerization pressure is usually normal pressure to 10 MPa, preferably 0.2 to 8.0 MPa. A chain transfer agent such as hydrogen can be used to adjust the molecular weight of the polymer.

In step (II), the content of the monomer unit based on propylene is 65 to 90% by weight (however, the content of all the monomer units of the polymer component is 100% by weight), which is the limit. This is a step of producing the polymer component (B) having a viscosity ([η] b) of 1 to 3 dl / g. Examples of the monomer other than propylene used in the step include olefins having 2 to 8 carbon atoms (excluding propylene) such as ethylene, 1-butene, 1-hexene, and 1-octene. These can be used alone or in combination of two or more. The monomer other than propylene is preferably ethylene.

The content of the propylene-based monomer unit of the polymer component produced in the step (II) is 65 to 90% by weight, assuming that the content of all the monomer units of the polymer component is 100% by weight. If the value is too small, the adhesive resistance of the polymer particles may be inferior, and if the value is too large, the impact resistance of the propylene-based polymer may be lowered. It is preferably 70 to 85% by weight, more preferably 75 to 80% by weight. The content of the monomer unit based on propylene is measured by infrared spectroscopy.

The ultimate viscosity ([η] b) of the polymer component produced in step (II) is 1 dl / g or more. If the value is too small, the adhesive resistance of the polymer particles may be inferior, and the impact resistance of the propylene-based polymer may be lowered. It is preferably 1.2 dl / g or more, and more preferably 1.5 dl / g or more. Further, the ultimate viscosity [η] b is preferably 3 dl / g or less, more preferably 2.7 dl / g or less, from the viewpoint of reducing the fish eye of the film when the propylene-based polymer is made into a film. More preferably, it is 2.5 dl / g or less. The ultimate viscosity is measured using a tetralin solution at 135 ° C.

Examples of the polymerization method of the step (II) include a bulk polymerization method, a solution polymerization method, a slurry polymerization method and a gas phase polymerization method as described in the polymerization method of the step (I), and these polymerization methods can be arbitrarily combined. These polymerization methods may be a batch type, a semi-batch type, or a continuous type. The polymerization method in step (II) is preferably a vapor phase polymerization method. Further, in the step (II), the polymerization temperature is usually 0 to 120 ° C, preferably 20 to 100 ° C, and the polymerization pressure is usually normal pressure to 10 MPa, preferably 0.2 to 8.0 MPa. A chain transfer agent such as hydrogen can be used to adjust the molecular weight of the polymer.

In step (III), the content of the monomer unit based on propylene is 30 to 60% by weight (however, the content of all the monomer units of the polymer component is 100% by weight), which is the limit. This is a step of producing a polymer component (C) having a viscosity ([η] c) of 1.5 to 9 dl / g and having the [η] c larger than [η] b. Examples of the monomer other than propylene used in the step include olefins having 2 to 8 carbon atoms (excluding propylene) such as ethylene, 1-butene, 1-hexene, and 1-octene. These can be used alone or in combination of two or more. The monomer other than propylene is preferably ethylene.

The content of the propylene-based monomer unit of the polymer component produced in the step (III) is 30 to 60% by weight, assuming that the content of all the monomer units of the polymer component is 100% by weight. If the value is too small or too large, the impact resistance of the propylene-based polymer may decrease. It is preferably 35 to 60% by weight, more preferably 40 to 55% by weight. The content of the monomer unit based on propylene is measured by infrared spectroscopy.

The ultimate viscosity ([η] c) of the polymer component produced in step (III) is 1.5 dl / g or more. If the value is too small, the adhesive resistance of the polymer particles may be inferior. From the viewpoint of enhancing the adhesive resistance of the polymer particles and the impact resistance of the propylene-based polymer, it is preferably 1.7 dl / g or more, and more preferably 2 dl / g or more. The ultimate viscosity [η] c is preferably 9 dl / g or less, more preferably 8 dl / g or less, and further preferably 7 dl / g or less from the viewpoint of enhancing extrusion processability. Further, when the [η] c has the same value as [η] b or a value smaller than [η] b, the adhesive resistance of the polymer particles may be inferior. The ultimate viscosity is measured using a tetralin solution at 135 ° C.

Examples of the polymerization method of the step (III) include a bulk polymerization method, a solution polymerization method, a slurry polymerization method and a gas phase polymerization method as described in the polymerization method of the step (I), and these polymerization methods can be arbitrarily combined. These polymerization methods may be a batch type, a semi-batch type, or a continuous type. The polymerization method in step (III) is preferably a vapor phase polymerization method. Further, in the step (III), the polymerization temperature is usually 0 to 120 ° C, preferably 20 to 100 ° C, and the polymerization pressure is usually normal pressure to 10 MPa, preferably 0.2 to 8.0 MPa. A chain transfer agent such as hydrogen can be used to adjust the molecular weight of the polymer.

The production method of the present invention is a method for producing a propylene-based polymer having a step (II) and a step (III) after the step (I), in the order of step (I) -step (II) -step (III). It may be carried out in the order of step (I)-step (III) -step (II). Further, it may have a plurality of steps (I), and further, it may have a plurality of steps (II) and / or a plurality of steps (III). For example, process (I) -1 / process (I) -2 / process (II) / process (III), process (I) / process (II) -1 / process (II) -2 / process (III), Process (I) / Process (II) / Process (III) -1 / Process (III) -2, Process (I) / Process (II) -1 / Process (III) -1 / Process (II) -2 / Step (III) -2 may be performed in this order.

The content of the polymer component (A) produced in the step (I) in the propylene polymer is 55 to 85% by weight, assuming that the propylene polymer is 100% by weight, and the polymer component (A) is produced in the step (II). The content of the polymer component (B) in the propylene-based polymer is 5 to 15% by weight, and the content of the polymer component (C) produced in the step (III) in the propylene-based polymer is 10. ~ 30% by weight. If the content of the polymer (A) is too small, the adhesive resistance of the polymer particles may be inferior, and if it is too large, the impact resistance of the propylene-based polymer may be lowered. It is preferably 58 to 81% by weight, more preferably 62 to 78% by weight. If the content of the polymer (B) is too small, the adhesive resistance of the polymer particles may be inferior, and if it is too large, the impact resistance of the propylene-based polymer may be lowered. It is preferably 7 to 15% by weight, more preferably 7 to 13% by weight. If the content of the polymer (C) is too small, the impact resistance of the propylene-based polymer may decrease, and if it is too large, the adhesive resistance of the polymer particles may be deteriorated. It is preferably 12 to 27% by weight, more preferably 15 to 25% by weight.

As the polymerization catalyst used in the production method of the present invention, a known olefin polymerization catalyst can be used. For example, a solid catalyst component containing titanium, magnesium, halogen and an electron donor (hereinafter referred to as catalyst component (A)). ), A polymerization catalyst composed of an organoaluminum compound component and an electron donor component can be mentioned.

The catalyst component (A) can be used as a titanium-magnesium composite type and what is generally called a catalyst, and can be obtained by contacting the following titanium compound, magnesium compound, and electron donor. Can be done.

Examples of the titanium compound used for adjusting the catalyst component (A) include the general formula Ti (OR).¹)_aX_4-a(R¹Represents a hydrocarbon group having 1 to 20 carbon atoms, X represents a halogen atom, and a represents a number of 0 a 4. ) Can be mentioned. Specifically, tetrahalogenated titanium compounds such as titanium tetrachloride; trihalogenated alkoxytitanium compounds such as ethoxytitanium trichloride and butoxytitanium trichloride; dihalogenated dialkoxytitanium such as diethoxytitanium dichloride and dibutoxytitanium dichloride. Compounds; Monohalogenated trialkoxytitanium compounds such as triethoxytitanium chloride and tributoxytitanium chloride; Tetraalkoxytitanium compounds such as tetraethoxytitanium and tetrabutoxytitanium can be mentioned. These titanium compounds may be used alone or in combination of two or more.

Examples of the magnesium compound used for adjusting the catalyst component (A) include a magnesium compound having a magnesium-carbon bond and a magnesium-hydrogen bond and having a reducing ability, a magnesium compound having no reducing ability, and the like. .. Specific examples of the magnesium compound having a reducing ability include dialkylmagnesium compounds such as dimethylmagnesium, diethylmagnesium, dibutylmagnesium and butylethylmagnesium; alkylmagnesium halide compounds such as butylmagnesium chloride; alkylalkoxymagnesium compounds such as butylethoxymagnesium; Examples thereof include alkylmagnesium hydrides such as butylmagnesium hydrides. These magnesium compounds having a reducing ability may be used in the form of a complex compound with an organoaluminum compound. On the other hand, specific examples of magnesium compounds having no reducing ability include dihalogenated magnesium compounds such as magnesium dichloride; alkoxymagnesium halide compounds such as methoxymagnesium chloride, ethoxymagnesium chloride and butoxymagnesium chloride; diethoxymagnesium and dibutoxymagnesium. Dialkoxymagnesium compounds such as; Magnesium laurate, magnesium carboxylates such as magnesium stearate, and the like. These magnesium compounds having no reducing ability may be synthesized in advance or at the time of preparation of the catalyst component (A) from the magnesium compound having a reducing ability by a known method.

The electron donors used to prepare the catalyst component (A) include alcohols, phenols, ketones, aldehydes, carboxylic acids, organic and inorganic acid esters, ethers, acid amides, and acid anhydrides. Oxygen-containing electron donors such as, etc .; Nitrogen-containing electron donors such as ammonia, amines, nitriles, isocyanates, etc .; Organic acid halides can be mentioned. Of these electron donors, preferably inorganic acid esters, organic acid esters and ethers are used.

The general formula R is preferable as an ester of an inorganic acid.²_nSi (OR³)_4-n(R²Represents a hydrocarbon group or hydrogen atom with 1 to 20 carbon atoms, and R³Represents a hydrocarbon group having 1 to 20 carbon atoms. In addition, n represents a number of 0 n &lt;4. ) Can be mentioned. Specifically, tetraalkoxysilanes such as tetramethoxysilane, tetraethoxysilane, and tetrabutoxysilane; methyltrimethoxysilane, ethyltrimethoxysilane, butyltrimethoxysilane, isobutyltrimethoxysilane, t-butyltrimethoxysilane, and methyl. Alkyltrialkoxysilanes such as triethoxysilane, ethyltriethoxysilane, butyltriethoxysilane, isobutyltriethoxysilane, t-butyltriethoxysilane; dimethyldimethoxysilane, diethyldimethoxysilane, dibutyldimethoxysilane, diisobutyldimethoxysilane, di- t-butyldimethoxysilane, butylmethyldimethoxysilane, butylethyldimethoxysilane, t-butylmethyldimethoxysilane, dimethyldiethoxysilane, diethyldiethoxysilane, dibutyldiethoxysilane, diisobutyldiethoxysilane, di-t-butyldiethoxy Examples thereof include dialkyldialkoxysilanes such as silane, butylmethyldiethoxysilane, butylethyldiethoxysilane, and t-butylmethyldiethoxysilane.

Mono and polyvalent carboxylic acid esters are preferably used as the esters of organic acids, and examples thereof include aliphatic carboxylic acid esters, alicyclic carboxylic acid esters, and aromatic carboxylic acid esters. Specific examples include methyl acetate, ethyl acetate, methyl propionate, ethyl propionate, ethyl butyrate, ethyl valerate, methyl acrylate, ethyl acrylate, methyl methacrylate, ethyl benzoate, butyl benzoate, methyl tolulate, etc. Ethyl toluate, ethyl anisate, diethyl succinate, dibutyl succinate, diethyl malonate, dibutyl malonate, dimethyl maleate, dibutyl maleate, diethyl itaconic acid, dibutyl itaconic acid, diethyl phthalate, di-n-phthalate Examples thereof include butyl and diisobutyl phthalate. It is preferably an unsaturated aliphatic carboxylic acid ester such as a methacrylic acid ester and a phthalate ester such as a maleic acid ester, and more preferably a phthalic acid diester.

Examples of ethers include dialkyl ethers such as diethyl ether, dibutyl ether, diisobutyl ether, diamyl ether, diisoamyl ether, methylbutyl ether, methylisoamyl ether, and ethylisobutyl ether. Dibutyl ether and diisoamyl ether are preferable.

Examples of the organic acid halides include mono and polyvalent carboxylic acid halides, and examples thereof include aliphatic carboxylic acid halides, alicyclic carboxylic acid halides, and aromatic carboxylic acid halides. Specific examples include acetyl chloride, propionic acid chloride, butyric acid chloride, itaconic acid chloride, acrylic acid chloride, methacrylate chloride, benzoyl chloride, tolurate chloride, anisic acid chloride, succinic acid chloride, malonic acid chloride, maleic acid chloride, Itaconic acid chloride, phthalic acid chloride and the like can be mentioned. Aromatic carboxylic acid chlorides such as benzoyl chloride, toluic acid chloride, and phthalic acid chloride are preferable, and phthalic acid chloride is more preferable.

Examples of the method for adjusting the catalyst component (A) include the following methods. (1) A method in which a liquid magnesium compound or a complex compound composed of a magnesium compound and an electron donor is reacted with a precipitation agent and then treated with a titanium compound or a titanium compound and an electron donor. (2) A method of treating a solid magnesium compound or a complex compound composed of a solid magnesium compound and an electron donor with a titanium compound, or a titanium compound and an electron donor. (3) A method in which a liquid magnesium compound and a liquid titanium compound are reacted in the presence of an electron donor to precipitate a solid titanium-magnesium composite. (4) A method for further treating the reaction product obtained in (1), (2) or (3) with a titanium compound, or an electron donor and a titanium compound. (5) A method for treating a solid product obtained by reducing an alkoxytitanium compound with an organic magnesium compound such as a Grignard reagent in the presence of an organosilicon compound having a Si-O bond with an ester compound, an ether compound and titanium tetrachloride. .. (6) The solid product obtained by reducing the titanium compound with the organic magnesium compound in the presence of the organic silicon compound or the organic silicon compound and the ester compound is a mixture of an ether compound and titanium tetrachloride, followed by an organic acid halide compound. A method in which the treated solid is treated with a mixture of an ether compound and titanium tetrachloride or a mixture of an ether compound, titanium tetrachloride and an ester compound. (7) A method of contacting a contact reaction product with a metal oxide, dihydrocarbyl magnesium and a halogen-containing alcohol with an electron donor and a titanium compound after or without treatment with a halogenating agent. (8) A method of contacting a magnesium compound such as a magnesium salt of an organic acid or an alkoxymagnesium with an electron donor and a titanium compound after or without treatment with a halogenating agent. (9) A method for treating the compounds obtained in (1) to (8) with any of halogens, halogen compounds or aromatic hydrocarbons. These catalyst components (A ) Are preferably the methods (1) to (6). All of these adjustments are usually performed in an atmosphere of an inert gas such as nitrogen or argon.

In the preparation of the catalyst component (A), the titanium compound, the organosilicon compound and the ester compound are preferably used after being dissolved or diluted in an appropriate solvent. Examples of such a solvent include aliphatic hydrocarbons such as hexane, heptane, octane and decane; aromatic hydrocarbons such as toluene and xylene; alicyclic hydrocarbons such as cyclohexane, methylcyclohexane and decalin; diethyl ether. Examples thereof include ether compounds such as dibutyl ether, diisoamyl ether and tetrahydrofuran.

In the preparation of the catalyst component (A), the temperature of the reduction reaction using the organic magnesium compound is usually -50 to 70 ° C, preferably -30 to 50 ° C, particularly from the viewpoint of increasing the catalytic activity and cost. It is preferably -25 to 35 ° C. The dropping time of the organic magnesium compound is not particularly limited, but is usually about 30 minutes to 12 hours. Further, after the reduction reaction is completed, the post-reaction may be further carried out at a temperature of 20 to 120 ° C.

In the preparation of the catalyst component (A), a porous substance such as an inorganic oxide or an organic polymer may coexist during the reduction reaction, and the porous substance may be impregnated with the solid product. The porous substance preferably has a pore volume of 0.3 ml / g or more and an average particle diameter of 5 to 300 μm at a pore radius of 20 to 200 nm. The porous inorganic oxide is SiO₂, Al₂O₃, MgO, TiO₂, ZrO₂Alternatively, these composite oxides and the like can be mentioned. Examples of the porous polymer include polystyrene-based porous polymers such as polystyrene and styrene-divinylbenzene copolymers; ethyl polyacrylate, methyl-divinylbenzene copolymer, polymethyl methacrylate, and methyl-divinyl methacrylate. Polyacrylic acid ester-based porous polymers such as benzene copolymers; polyolefin-based porous polymers such as polyethylene, ethylene-methyl acrylate copolymers, and polypropylene can be mentioned. Of these porous materials, SiO is preferable.₂, Al₂O₃, Styrene-divinylbenzene copolymer.

The organoaluminum compound component used in the polymerization catalyst has at least one Al-carbon bond in the molecule, and a typical one is shown below in a general formula. R⁴_mAlY_3-m R⁵R⁶Al-O-AlR⁷R⁸(R⁴~ R⁸Represents a hydrocarbon group having 1 to 8 carbon atoms, and Y represents a halogen atom, hydrogen or alkoxy group. R⁴~ R⁸May be the same or different. Further, m is a number represented by 2 m 3. )

Specific examples of organoaluminum compound components include trialkylaluminum such as triethylaluminum and triisobutylaluminum; dialkylaluminum hydride such as diethylaluminum hydride and diisobutylaluminum hydride; dialkylaluminum halide such as diethylaluminum chloride and diisobutylaluminum chloride; triethylaluminum. And a mixture of trialkylaluminum and dialkylaluminum halide, such as a mixture of diethylaluminum chloride; alkylalmoxane such as tetraethyldialmoxane, tetrabutyldialmoxane and the like. Among these organoaluminum compounds, trialkylaluminum, a mixture of trialkylaluminum and dialkylaluminum halide, alkylarmoxane is preferable, and triethylaluminum, triisobutylaluminum, a mixture of triethylaluminum and diethylaluminum chloride, or a mixture of triethylaluminum and diethylaluminum chloride is more preferable. Tetraethyldialmoxane is preferred.

The electron donor component used in the polymerization catalyst includes alcohols, phenols, ketones, aldehydes, carboxylic acids, esters of organic or inorganic acids, ethers, acid amides, acid anhydrides and the like. Oxygen electron donors; commonly used substances such as nitrogen-containing electron donors such as ammonia, amines, nitriles, and isocyanates can be mentioned. Of these electron donor components, esters and ethers of inorganic acids are preferable.

The general formula R is preferable as the esters of the inorganic acid.⁹_nSi (OR¹⁰)_4-n(In the formula, R⁹Is a hydrocarbon group or hydrogen atom with 1 to 20 carbon atoms, R¹⁰Is a hydrocarbon group having 1 to 20 carbon atoms, and n is a silicon compound represented by 0 n &lt;4). Specific examples include tetrabutoxysilane, butyltrimethoxysilane, tert-butyl-n-propyldimethoxysilane, dicyclopentyldimethoxysilane, cyclohexylethyldimethoxysilane, and the like.

The ethers are preferably dialkyl ethers, of the general formula.<img file="JP2005290102A_D0001.tif" />(In the formula, R¹¹~ R¹⁴Is a linear or branched alkyl group with 1 to 20 carbon atoms, an alicyclic hydrocarbon group, an aryl group, or an aralkyl group, and R¹¹Or R¹²May be a hydrogen atom. ) Can be mentioned. Specific examples include dibutyl ether, diamyl ether, 2,2-diisobutyl-1,3-dimethoxypropane, 2,2-dicyclopentyl-1,3-dimethoxypropane and the like.

Of these electron donor components, the general formula R¹⁵R¹⁶Si (OR¹⁷)₂The organosilicon compound represented by is particularly preferably used. Here in the formula, R¹⁵Is a hydrocarbon group having 3 to 20 carbon atoms in which the carbon atom adjacent to Si is secondary or tertiary. Specifically, isopropyl group, sec-butyl group, tert-butyl group, tert-amyl group, etc. Branched chain alkyl group; cycloalkyl group such as cyclopentyl group and cyclohexyl group; cycloalkenyl group such as cyclopentenyl group; aryl group such as phenyl group and tolyl group. Also in the formula, R¹⁶Is a hydrocarbon group having 1 to 20 carbon atoms, specifically, a linear alkyl group such as a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group; an isopropyl group, a sec-butyl group, a tert- Branched chain alkyl groups such as butyl group and tert-amyl group; cycloalkyl groups such as cyclopentenyl group and cyclohexyl group; cycloalkenyl groups such as cyclopentenyl group; aryl groups such as phenyl group and tolyl group can be mentioned. Furthermore, in the formula, R¹⁷Is a hydrocarbon group having 1 to 20 carbon atoms, preferably a hydrocarbon group having 1 to 5 carbon atoms. Specific examples of the organosilicon compound used as such an electron donor component include tert-butyl-n-propyldimethoxysilane, dicyclopentyldimethoxysilane, cyclohexylethyldimethoxysilane, and the like.

In the preparation of the polymerization catalyst, the amount of the organoaluminum compound used is usually 1 to 1000 mol, preferably 5 to 800 mol, per 1 mol of titanium atoms contained in the catalyst component (A). The amount of the electron donor component used is usually 0.1 to 2000 mol, preferably 0.3 to 1000 mol, and more preferably 0.5 to 800 mol per 1 mol of titanium atoms contained in the catalyst component (A).

The catalyst component (A) may be used as a prepolymerization catalyst component by polymerizing a small amount of olefin (hereinafter referred to as prepolymerization) before subjecting it to the polymerization of steps (I) to (III). The amount of olefin to be prepolymerized is usually 0.1 to 200 g per 1 g of the catalyst component (A), and examples of the method of prepolymerization include known methods, for example, the catalyst component (A) and organoaluminum. In the presence of the compound, a method of supplying a small amount of propylene and using a solvent in a slurry state can be mentioned. Solvents used for prepolymerization include inert saturated hydrocarbons such as propane, butane, isobutane, pentane, isopentane, hexane, heptane, octane, cyclohexane, benzene, and toluene, and liquid propylene. It may be mixed and used. The amount of the organoaluminum compound used in the prepolymerization is 0.1 to 70 mol, preferably 0.2 to 50 mol, and more preferably 0.5 to 20 mol per 1 mol of titanium atom contained in the catalyst component (A). Yes, in the prepolymerization, an electron donor may coexist if necessary, or a chain transfer agent such as hydrogen may be used. The slurry concentration in the prepolymerization is 0.2 to 200 g as the weight of the catalyst component (A) contained in 1 L of the solvent, and the prepolymerization temperature is -20 to 50 ° C.

Hereinafter, the present invention will be described with reference to Examples and Comparative Examples. Physical property measurement and evaluation in the examples were carried out by the following methods. (1) Calorie of fusion (Unit: J / g) Measured under the following conditions using a differential scanning calorimeter (DSC-7 manufactured by PerkinElmer). (i) Approximately 10 mg of the sample was heated from 50 ° C to 220 ° C at a heating rate of 200 ° C / min, and held for 5 minutes after the temperature was completed. (ii) Next, the temperature was lowered from 220 ° C to 70 ° C / min to 180 ° C, and the temperature was maintained for 5 minutes after the temperature reduction was completed. (iii) Next, the temperature was lowered from 180 ° C to 200 ° C / min to 50 ° C, and the temperature was maintained for 1 minute after the temperature reduction was completed. (iv) Next, the temperature was raised from 50 ° C to 180 ° C at a heating rate of 16 ° C / min. The curve obtained in (iv) is the melting curve, and the amount of heat of fusion connects the point of the melting curve at 95 ° C and the point where the melting curve returns to the baseline on the high temperature side (about 175 ° C) with a straight line. It was calculated using a grid line. (2) Extreme viscosity (unit: dl / g) Using a Ubbelohde viscometer, the reduced viscosities were measured at three points at concentrations of 0.1, 0.2, and 0.5 g / dl under the conditions of a tetralin solvent and a temperature of 135 ° C. Next, extrapolation in which the reduced viscosity is plotted against the concentration and the concentration is extrapolated to zero according to the calculation method described on page 491 of "Polymer Solution, Polymer Experiment 11" (published by Kyoritsu Shuppan Co., Ltd. in 1982). The ultimate viscosity was determined by the method. (3) Propylene unit content (unit: weight%) Obtained by infrared absorption spectroscopy.

(4) Amount of polymer component produced in each polymerization step (unit: weight%) Amount of polymer component produced in polymerization step (1) Xa (% by weight), polymer component produced in polymerization step (2) The amount Xb (% by weight) and the amount of polymer component Xc (% by weight) produced in the polymerization step (3) were calculated by the following formulas. Xa = ΔH3 / ΔH1 × 100 Xb = (ΔH1 / ΔH2-1) × ΔH3 / ΔH1 × 100 Xc = 100-Xa-Xb ΔH1: Amount of heat of fusion (J / g) ΔH2: of polymer after polymerization step (1) Heat of fusion of polymer after polymerization step (2) (J / g) ΔH3: Heat of fusion of polymer after polymerization step (3) (J / g) (5) Extreme viscosity of polymer produced in each polymerization step (Unit: dl / g) Extreme viscosity of the polymer component produced in the polymerization step (1) [η] a (dl / g), Extreme viscosity of the polymer component produced in the polymerization step (2) [η] b ( The ultimate viscosity [η] c (dl / g) of the polymer component produced in dl / g) and the polymerization step (3) was calculated by the following formula. [η] a = [η] 1 [η] b = ([η] 2- [η] a × (Xa / (Xa + Xb))) × (Xa + Xb) / Xb [η] c = ([η] 3- [η] 2 × (Xa + Xb) / 100) × 100 / Xc [η] 1: Extreme viscosity (dl / g) of the polymer after the polymerization step (1) [η] 2: Extreme viscosity of polymer after polymerization step (2) (dl / g) [η] 3: Extreme viscosity of polymer after polymerization step (3) (dl / g) (6) Each polymerization step The propylene unit content of the polymer component produced in (Unit:% by weight) The propylene unit content of the polymer component produced in the polymerization step (1) (Unit:% by weight), the polymer produced in the polymerization step (2) The propylene unit content (unit: wt%) of the component and the propylene unit content (unit: wt%) of the polymer component produced in the polymerization step (3) were calculated by the following formulas. Pa = P1 Pb = (P2-Pa × (Xa / (Xa + Xb))) × (Xa + Xb) / Xb Pc = (P3-P2 × (Xa + Xb) / 100) × 100 / Xc P1: Polymerization The propylene unit content of the polymer after the step (1) (unit: wt%) P2: The propylene unit content of the polymer after the polymerization step (2) (unit: wt%) P3: propylene unit content of polymer after polymerization step (3) (unit: weight%) (7) Bulk specific weight of polymer particles (unit: g / cm)³) According to JIS K6721, the measurement was performed using a bulk specific gravity measuring device.

(8) Adhesive resistance of polymer particles The adhesive resistance of the obtained polymer particles was evaluated by touch as follows. : The texture is smooth and there is no mutual adhesion between particles. X: Particles with a sticky feeling and high adhesiveness.

Example 1 [Preparation of solid catalyst component]

After replacing a SUS reaction vessel with a stirrer with an internal volume of 200 L with nitrogen, 80 L of hexane, 6.55 mol of tetrabutoxytitanium, 2.8 mol of diisobutyl phthalate, and 98.9 mol of tetraethoxysilane were added to prepare a uniform solution. Next, 51 L of a diisobutyl ether solution of butylmagnesium chloride having a concentration of 2.1 mol / L was gradually added dropwise over 5 hours while maintaining the temperature in the reaction vessel at 5 ° C. After completion of the dropping, the mixture was stirred at room temperature for 1 hour, separated into solid and liquid at room temperature, and then washed 3 times with 70 L of toluene. Then, after adding toluene so that the slurry concentration became 0.2 kg / L, 47.6 mol of diisobutyl phthalate was added, and the reaction was carried out at 95 ° C. for 30 minutes. After the reaction, it was separated into solid and liquid, and washed twice with toluene. Then, 3.13 mol of diisobutyl phthalate, 8.9 mol of butyl ether and 274 mol of titanium tetrachloride were added, and the reaction was carried out at 105 ° C. for 3 hours. After completion of the reaction, solid-liquid separation was performed at the same temperature, and washing was performed twice with 90 L of toluene at the same temperature. Then, after adjusting the slurry concentration to 0.4 kg / L, 8.9 mol of butyl ether and 137 mol of titanium tetrachloride were added, and the reaction was carried out at 105 ° C. for 1 hour. After completion of the reaction, solid-liquid separation was performed at the same temperature, the mixture was washed 3 times with 90 L of toluene at the same temperature, then washed 3 times with 70 L of hexane, and dried under reduced pressure to obtain 11.4 kg of a solid catalyst component.

[Prepolymerization]

To a SUS autoclave with an internal volume of 3 L and a stirrer, 1.5 L of fully dehydrated and degassed n-hexane, 37.5 mmol of triethylaluminum, 3.75 mmol of t-butyl-n-propyldimethoxysilane and 15 g of the above solid catalyst component were added. Then, while maintaining the temperature inside the autoclave at about 10 ° C, 15 g of propylene was continuously supplied over about 30 minutes to perform prepolymerization, and then the prepolymerized slurry was transferred to a SUS autoclave with an internal volume of 150 L and equipped with a stirrer. Then, 100 L of liquid butane was added to prepare a slurry of the prepolymerization catalyst component.

[Polymerization step (1)]

Internal volume 1m³Using a fluidized bed reactor with a stirrer, a slurry of propylene, hydrogen, triethylaluminum, t-butyl-n-propyldimethoxysilane and prepolymerization catalyst components was continuously supplied, and the polymerization temperature: 80 ° C., polymerization pressure. : 1.8MPa, circulating gas air volume: 100m³/ Hour, concentration ratio of hydrogen to propylene in reactor gas: 10% by volume / 90% by volume (hydrogen concentration / propylene concentration), supply of triethylaluminum: 40 mmol / hour, t-butyl-n-propyldimethoxysilane Supply amount: 4 mmol / hour, supply amount of slurry of prepolymerization catalyst component: 0.98 g / hour in terms of solid catalyst component, polymer particle holding amount of fluid bed: 70 kg, continuous polymerization was performed for 12 hours. .. Next, the supply of the slurry of the prepolymerization catalyst component and the discharge of the polymer are stopped, and propylene and hydrogen are continuously supplied, the polymerization temperature: 80 ° C, the polymerization pressure: 1.8 MPa, the circulating gas air volume: 100 m.³Polymerization was carried out under the conditions of / hour, concentration ratio of hydrogen and propylene in the gas in the reactor: 10% by volume / 90% by volume (hydrogen concentration / propylene concentration) until the polymer particle holding amount of the fluidized bed reached 90 kg. .. The ultimate viscosity [η] 1 of the obtained polymer particles was 0.91 dl / g, and the heat of fusion ΔH1 was 102.9 J / g.

[Polymerization step (2)]

Internal volume 1 m different from the reactor used in the polymerization step (1)³After replacing the fluidized bed reactor with a stirrer in the above with a nitrogen atmosphere, 38.5 kg of the polymer particles obtained in the above polymerization step (1) was transferred into the fluidized bed reactor, and then 20 mmol of tetraethoxysilane was transferred to the reactor. Into, propylene, ethylene and hydrogen are continuously supplied, polymerization temperature: 65 ° C, polymerization pressure: 1.0MPa, circulating gas air volume: 150m.³Polymerization was carried out for 0.6 hours under the conditions of concentration ratio of propylene, ethylene and hydrogen in the reactor gas: 79% by volume / 17% by volume / 4% by volume (propylene concentration / ethylene concentration / hydrogen concentration). The ultimate viscosity [η] 2 of the obtained polymer particles was 0.94 dl / g, the propylene unit amount P2 was 98.6% by weight, and the heat of fusion ΔH2 was 97.2 J / g.

[Polymerization step (3)]

After the above polymerization step (2), the inside of the fluidized bed reactor is stepped down and replaced with a nitrogen atmosphere, and then propylene, ethylene and hydrogen are continuously supplied, the polymerization temperature: 65 ° C, the polymerization pressure: 1.1 MPa, Circulating gas air volume: 150m³Gas phase polymerization was carried out for 2.2 hours under the conditions of / hour, concentration ratio of propylene, ethylene and hydrogen in the reactor gas: 68.8% by volume / 27% by volume / 4.2% by volume (propylene concentration / ethylene concentration / hydrogen concentration). The ultimate viscosity [η] 3 of the obtained polymer particles was 1.05 dl / g, the propylene unit amount P3 was 94.7% by weight, and the heat of fusion ΔH3 was 87.5 J / g. The bulk specific gravity of the polymer particles is 0.400 g / cm.³Met. Tables 1 and 2 show the analysis results of the polymer components produced in each polymerization step and the evaluation results of the polymer particles obtained in the polymerization step (3).

Comparative Example 1 [Polymerization Step (1)]

Internal volume 1m³Using a fluidized bed reactor with a stirrer, a slurry of propylene, hydrogen, triethylaluminum, t-butyl-n-propyldimethoxysilane and the prepolymerization catalyst component prepared in Example 1 was continuously supplied, and the polymerization temperature: 80 ° C, polymerization pressure: 1.8MPa, circulating gas air volume: 100m³/ Hour, propylene to hydrogen concentration ratio in reactor gas: 89.8% by volume / 10.2% by volume (propylene concentration / hydrogen concentration), triethylaluminum supply: 40 mmol / hour, t-butyl-n-propyldimethoxysilane Supply amount: 4 mmol / hour, supply amount of slurry of prepolymerization catalyst component: 1.0 g / hour in terms of solid catalyst component, polymer particle holding amount of fluid bed: 70 kg, 12-hour polymerization was carried out. Next, the supply of the slurry of the prepolymerization catalyst component and the discharge of the polymer are stopped, and propylene and hydrogen are continuously supplied, the polymerization temperature: 80 ° C, the polymerization pressure: 1.8 MPa, the circulating gas air volume: 100 m.³Polymerization was carried out under the conditions of / hour and the concentration ratio of propylene to hydrogen in the gas in the reactor: 89.8% by volume / 10.2% by volume (propylene concentration / hydrogen concentration) until the polymer particle holding amount of the fluidized bed reached 90 kg. .. The ultimate viscosity [η] 1 of the obtained polymer particles was 0.91 dl / g, and the heat of fusion ΔH1 was 103.5 J / g.

[Polymerization step (2)]

Internal volume 1 m different from the reactor used in the polymerization step (1)³After replacing the fluidized bed reactor with a stirrer in the above with a nitrogen atmosphere, 31.8 kg of the polymer particles obtained in the above polymerization step (1) was transferred into the fluidized bed reactor, and then 20 mmol of tetraethoxysilane was transferred to the reactor. Into, propylene, ethylene and hydrogen are continuously supplied, polymerization temperature: 65 ° C, polymerization pressure: 1.0MPa, circulating gas air volume: 150m.³Polymerization was carried out for 2.5 hours under the conditions of / hour, concentration ratio of propylene, ethylene and hydrogen in the reactor gas: 71.5% by volume / 24% by volume / 4.5% by volume (propylene concentration / ethylene concentration / hydrogen concentration). The ultimate viscosity [η] 2 of the obtained polymer particles was 1.03 dl / g, the propylene unit amount P2 was 94.7% by weight, and the heat of fusion ΔH2 was 88.0 J / g. The bulk specific gravity of the polymer particles is 0.360 g / cm.³Met. Tables 1 and 2 show the analysis results of the polymer components produced in each polymerization step and the evaluation results of the polymer particles obtained in the polymerization step (2).

Example 2 Concentration ratio of propylene, ethylene and hydrogen in the reactor gas in the polymerization step (2) of Example 1: 84.8% by volume / 13% by volume / 2.2% by volume (propylene concentration / ethylene concentration / hydrogen concentration), The polymerization time was 1.9 hours, and the concentration ratio of propylene, ethylene, and hydrogen in the reaction gas in the polymerization step (3) of Example 1 was 70.2% by volume / 27% by volume / 2.8% by volume (propylene concentration / ethylene concentration /). The same procedure as in Example 1 was carried out except that the hydrogen concentration) and the polymerization time were set to 3.5 hours. The ultimate viscosity [η] 1 of the polymer particles obtained in the polymerization step (1) is 0.91 dl / g, the calorific value ΔH1 is 103.0 J / g, and the limit of the polymer particles obtained in the polymerization step (2). The viscosity [η] 2 is 1.05 dl / g, the propylene unit amount P2 is 97.1% by weight, the heat of fusion ΔH2 is 87.9 J / g, and the ultimate viscosity [η] 3 of the polymer particles obtained in the polymerization step (3). Is 1.41 dl / g, the propylene unit amount P3 is 87.7% by weight, the heat of fusion ΔH3 is 65.9 J / g, and the bulk specific gravity of the polymer particles is 0.404 g / cm.³Met. Tables 1 and 2 show the analysis results of the polymer components produced in each polymerization step and the evaluation results of the polymer particles obtained in the polymerization step (3).

Comparative Example 2 Concentration ratio of propylene, ethylene and hydrogen in the reactor gas in the polymerization step (2) of Example 1: 81.4% by volume / 13% by volume / 5.6% by volume (propylene concentration / ethylene concentration / hydrogen concentration), The polymerization time was 1.9 hours, and the concentration ratio of propylene, ethylene, and hydrogen in the reaction gas in the polymerization step (3) of Example 1 was 68.4% by volume / 27% by volume / 4.6% by volume (propylene concentration / ethylene concentration /). The same procedure as in Example 1 was carried out except that the hydrogen concentration) and the polymerization time were set to 3.5 hours. The ultimate viscosity [η] 1 of the polymer particles obtained in the polymerization step (1) is 0.91 dl / g, the calorific value ΔH1 is 104.1 J / g, and the limit of the polymer particles obtained in the polymerization step (2). The viscosity [η] 2 is 1.24 dl / g, the propylene unit amount P2 is 97.1% by weight, and the heat of fusion ΔH2 is 88.8 J / g. 1.40 dl / g, propylene unit amount P3 is 87.7% by weight, heat of fusion ΔH3 is 66.6 J / g, and the bulk specific gravity of the polymer particles is 0.342 g / cm.³Met. Tables 1 and 2 show the analysis results of the polymer components produced in each polymerization step and the evaluation results of the polymer particles obtained in the polymerization step (3).

Comparative Example 3 Concentration ratio of propylene, ethylene and hydrogen in the reactor gas in the polymerization step (2) of Comparative Example 1: 23.7% by volume / 70% by volume / 6.3% by volume (propylene concentration / ethylene concentration / hydrogen concentration), The same procedure as in Comparative Example 1 was carried out except that the polymerization time was 4.2 hours. The ultimate viscosity [η] 1 of the polymer particles obtained in the polymerization step (1) is 0.91 dl / g, and the calorific value ΔH1 is 103.6 J / g, which is the limit of the polymer particles obtained in the polymerization step (2). Viscosity [η] 2 is 1.45 dl / g, propylene unit amount P2 is 77.1% by weight, heat of fusion ΔH2 is 71.5 J / g, and bulk specific gravity of polymer particles is 0.330 g / cm.³Met. Tables 1 and 2 show the analysis results of the polymer components produced in each polymerization step and the evaluation results of the polymer particles obtained in the polymerization step (3).

Example 3 In the polymerization step (1), ethylene is further continuously supplied to the fluidized bed reactor, and the concentration ratio of propylene, ethylene and hydrogen in the gas composition in the reactor: 83.6% by volume / 1.4% by volume / 15% by volume ( (Propylene concentration / ethylene concentration / hydrogen concentration), and the supply amount of the slurry of the prepolymerization catalyst component is 0.6 g / hour in terms of solid catalyst component, and the gas in the reactor in the polymerization step (2) is composed of propylene, ethylene, and hydrogen. Concentration ratio: 84.9% by volume / 13% by volume / 2.1% by volume (propylene concentration / ethylene concentration / hydrogen concentration), the polymerization time was 2.0 hours, and the propylene gas in the reactor in the polymerization step (3) of Example 1 The same procedure as in Example 1 was carried out except that the concentration ratio of ethylene and hydrogen was 70.1% by volume / 27% by volume / 2.9% by volume (propylene concentration / ethylene concentration / hydrogen concentration) and the polymerization time was 3.7 hours. The ultimate viscosity [η] 1 of the polymer particles obtained in the polymerization step (1) is 0.91 dl / g, the propylene unit amount P1 is 96.5% by weight, and the heat of fusion ΔH1 is 63.0 J / g. The ultimate viscosity [η] 2 of the polymer particles obtained in the above was 1.05 dl / g, the propylene unit amount P2 was 94.1% by weight, and the heat of fusion ΔH2 was 53.8 J / g. The ultimate viscosity [η] 3 of the coalesced particles is 1.41 dl / g, the propylene unit amount P3 is 85.5% by weight, the heat of fusion ΔH3 is 40.3 J / g, and the bulk specific gravity of the polymer particles is 0.395 g / cm.³Met. Tables 1 and 2 show the analysis results of the polymer components produced in each polymerization step and the evaluation results of the polymer particles obtained in the polymerization step (3).

Comparative example 4 In the polymerization step (1), ethylene is further continuously supplied to the fluidized bed reactor, and the concentration ratio of propylene, ethylene and hydrogen in the gas composition in the reactor: 79% by volume / 3.5% by volume / 17.5% by volume ( (Propylene concentration / ethylene concentration / hydrogen concentration), and the supply amount of the slurry of the prepolymerization catalyst component is 0.5 g / hour in terms of solid catalyst component. Concentration ratio: 84.9% by volume / 13% by volume / 2.1% by volume (propylene concentration / ethylene concentration / hydrogen concentration), the polymerization time was 2.1 hours, and the propylene gas in the reactor in the polymerization step (3) of Example 1 The same procedure as in Example 1 was carried out except that the concentration ratio of ethylene and hydrogen was 70.1% by volume / 27% by volume / 2.9% by volume (propylene concentration / ethylene concentration / hydrogen concentration) and the polymerization time was 3.8 hours. The ultimate viscosity [η] 1 of the polymer particles obtained in the polymerization step (1) is 0.91 dl / g, the propylene unit amount P1 is 94.0% by weight, and the heat of fusion ΔH1 is 59.0 J / g. The ultimate viscosity [η] 2 of the polymer particles obtained in the above was 1.05 dl / g, the propylene unit amount P2 was 91.8% by weight, and the heat of fusion ΔH2 was 50.4 J / g. The ultimate viscosity [η] 3 of the coalesced particles is 1.41 dl / g, the propylene unit amount P3 is 83.9% by weight, the heat of fusion ΔH3 is 37.7 J / g, and the bulk specific gravity of the polymer particles is 0.340 g / cm.³Met. Tables 1 and 2 show the analysis results of the polymer components produced in each polymerization step and the evaluation results of the polymer particles obtained in the polymerization step (3).

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