JP7532842B2 - Method for producing propylene polymer - Google Patents

Description

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

Polypropylene is the most important plastic material as an industrial material, and is widely used in a variety of applications, including as films or sheets for packaging materials and electrical materials, as molded articles for industrial materials such as automobile components and home appliances, and as textile materials and building materials.
Because polypropylene has such a wide and diverse range of uses, there has been a continuing demand for improvements and enhancements in various properties of polypropylene in order to meet these demands. In order to meet these demands, technological development has been carried out mainly through improvements in polymerization catalysts.

Ziegler catalysts using transition metal compounds and organometallic compounds have significantly increased the polymerization activity of propylene, making industrial production possible. Since then, many improvements have been made to the performance of propylene polymers, including improvements in the physical properties of the polymers due to their molecular weight distribution, reductions in the amount of amorphous components (polymers with low stereoregularity and low molecular weight), and improvements in stereoregularity.
Specifically, a catalyst using a solid catalyst component containing titanium and halogen as essential components with a magnesium compound as a catalyst carrier has been developed, and furthermore, a catalyst in which the catalytic activity and stereoregularity are enhanced by using an electron donor (see, for example, Patent Documents 1 to 3), and then, a proposal has been made to further improve the catalytic activity and stereoregularity by adding a specific organosilicon compound to the catalyst component (see Patent Document 4). In addition to the specific organosilicon compound, a proposal has been made to further improve the catalytic activity and stereoregularity by using a silicon compound with a special structure having an alkenyl group such as a vinyl group or an allyl group in combination with the specific organosilicon compound, thereby improving the performance such as improving the response of hydrogen used as a molecular weight regulator (see, for example, Patent Documents 5 to 8). Furthermore, a proposal has been made to reduce the amorphous component by using a specific amide compound or sulfite ester combined with an organosilicon compound as an external donor (see Patent Documents 9 and 10).
It has also been proposed to use an alkoxysilane compound as a selectivity control agent and a monoether compound as an activity limiter during polymerization to avoid contamination of the reactor due to softening of the polymer at high polymerization temperatures (see Patent Document 11). Furthermore, many improved techniques have been disclosed, such as incorporating a specific furan compound in a catalyst component at a certain ratio with an electron donor (see Patent Document 12).

Japanese Unexamined Patent Publication No. 58-138706 Japanese Unexamined Patent Publication No. 57-59909 Japanese Unexamined Patent Publication No. 58-147409 Japanese Unexamined Patent Publication No. 187707/1986 Japanese Patent Application Publication No. 03-234707 Japanese Patent Application Publication No. 07-2923 JP 2006-169283 A JP 2008-163151 A JP 2004-124090 A JP 2006-225449 A JP 2019-001992 A JP 2007-119514 A

However, as far as the present researchers are aware, none of these catalyst systems have been sufficient in improving the properties of the resulting propylene polymer, such as reducing the amount of amorphous components or increasing the stereoregularity, and improvements in various properties are required in each field of use. For example, in the field of automotive parts and materials, high rigidity is required for molded products, and further improvements are particularly desired in terms of high crystallinity, i.e., improving stereoregularity and reducing the amount of amorphous components, while in the field of packaging materials, there is a strong demand for further improvements in stickiness, etc.

The purpose of this application is to provide a method for producing a propylene-based polymer with improved stereoregularity and further reduced amorphous components to further increase rigidity in order to meet the demand for further improved performance in the field of polypropylene materials and propylene polymerization catalysts in the above-mentioned state of the art.

As a result of intensive research conducted by the present researchers to achieve the above objective, they discovered a method for producing a propylene-based polymer with a small amount of amorphous components and high stereoregularity.

The method for producing a propylene-based polymer of the present invention is characterized by comprising the following steps (I) and (II).
Step (I): A step of obtaining a solid catalyst component (A) by adding the following components (A2), (A3) and (A4) to the following component (A1): Component (A1): A solid component containing titanium, magnesium, a halogen and an electron donor as essential components; Component (A2): A silane compound having an alkenyl group; Component (A3): An alkoxysilane compound [however, different from the silane compound having an alkenyl group].
Component (A4): an organoaluminum compound; Step (II): a step of contacting the solid catalyst component (A) with the following components (B) and (C) in the presence of a polymerizable monomer, thereby polymerizing the polymerizable monomer: Component (B): an organoaluminum compound; Component (C): an unsaturated cyclic ether compound;

In the method for producing a propylene-based polymer of the present invention, the component (C) may be represented by the following general formula (1):

In the general formula (1), ^R1 and ^R2 are hydrogen atoms or hydrocarbon groups, and ^R1 and ^R2 may be the same or different.

In the method for producing a propylene-based polymer of the present invention, the component (A2) may be a vinylsilane compound.

In the method for producing a propylene-based polymer of the present invention, the component (A3) may be represented by the following general formula (2).
^R3R4mSi ( ^OR5 _{) n} ...( ² )
(In the general formula (2), ^R3 represents a hydrocarbon group or a heteroatom-containing hydrocarbon group. ^R4 represents hydrogen, a halogen, a hydrocarbon group or a heteroatom-containing hydrocarbon group. ^R5 represents a hydrocarbon group. m and n each represent an integer such that 0≦m≦2, 1≦n≦3, or m+n=3.)

In the method for producing a propylene-based polymer of the present invention, the polymerization monomer may be propylene, or propylene and ethylene, or propylene and an α-olefin having 4 to 22 carbon atoms.

The present invention provides a method for producing a propylene-based polymer with low amorphous content and high stereoregularity.

The method for producing a propylene-based polymer of the present invention is characterized by comprising the following steps (I) and (II).
Step (I): A step of obtaining a solid catalyst component (A) by adding the following components (A2), (A3) and (A4) to the following component (A1): Component (A1): A solid component containing titanium, magnesium, a halogen and an electron donor as essential components; Component (A2): A silane compound having an alkenyl group; Component (A3): An alkoxysilane compound [however, different from the silane compound having an alkenyl group].
Component (A4): an organoaluminum compound; Step (II): a step of contacting the solid catalyst component (A) with the following components (B) and (C) in the presence of a polymerizable monomer, thereby polymerizing the polymerizable monomer: Component (B): an organoaluminum compound; Component (C): an unsaturated cyclic ether compound;

The method for producing a propylene-based polymer of the present invention will be described in detail below for each item. In this specification, the use of "-" to indicate a range of values means that the values before and after the range are included as the lower and upper limits.

In polymerization techniques using Ziegler-Natta (ZN) catalysts, it is generally believed that the actions of internal donors and external donors are different.
The internal donor is a donor that is used simultaneously when the titanium compound is supported on the magnesium compound to form an active site, and it controls the location where the titanium atom is coordinated or changes the electronic state of the coordinated titanium atom.
On the other hand, the external donor changes the properties of already formed active sites. For example, by using an external donor for the solid catalyst component (A) prepared using an internal donor, it is possible to convert an active site that is not highly stereospecific to a highly stereospecific active site, or to poison an active site where an amorphous component is formed, and therefore it is possible to produce a propylene-based polymer with higher stereoregularity and higher molecular weight.
In the present invention, it is presumed that by using an unsaturated cyclic ether compound as component (C) as an external donor, the active sites that produce amorphous components are selectively poisoned, and the production of polymers with low stereoregularity and low molecular weight can be further reduced compared to the case where an unsaturated cyclic ether compound is used as an internal donor.

1. Step (I)
Step (I) is a step of adding components (A2), (A3) and (A4) to component (A1) to obtain solid catalyst component (A).

1-1. Solid component (A1)
The solid component (A1) according to the present invention contains magnesium (A1a-1), titanium (A1a-2), a halogen (A1a-3) and an electron donor (A1a-4) as essential components.

1-1-1. Magnesium (A1a-1)
Any magnesium compound can be used as the magnesium source for the solid component (A1) according to the present invention. Representative examples thereof include the compounds disclosed in JP-A-3-234707.
In general, magnesium halide compounds such as magnesium chloride, alkoxymagnesium compounds such as diethoxymagnesium, metallic magnesium, oxymagnesium compounds such as magnesium oxide, hydroxymagnesium compounds such as magnesium hydroxide, Grignard compounds such as butylmagnesium chloride, organic magnesium compounds such as butyloctylmagnesium, magnesium salt compounds of inorganic and organic acids such as magnesium carbonate and magnesium stearate, and mixtures thereof or compounds whose average composition formula is a mixture of these (for example, a compound such as Mg(OEt) _{mCl2 -m} ; 0<m<2) can be used.
Among these, magnesium chloride, diethoxymagnesium, metallic magnesium, and butylmagnesium chloride are particularly preferred.

In particular, when producing large particles, it is preferable to use dialkoxymagnesium, which allows easy control of catalyst particle size. Dialkoxymagnesium can be used not only when it is produced in advance, but also when it is produced by reacting metallic magnesium with alcohol in the presence of halogen or halogen-containing metal compound during the catalyst production process.

Furthermore, in the present invention, the dialkoxymagnesium suitable as component (A1a-1) is in the form of granules or powder, and the shape thereof may be amorphous or spherical.
For example, when a spherical dialkoxymagnesium is used, a polymer powder having a better particle shape and a narrower particle size distribution can be obtained, the handling operability of the produced polymer powder during the polymerization operation is improved, and problems such as blockage caused by fine powder contained in the produced polymer powder are eliminated.

The above-mentioned spherical dialkoxymagnesium does not necessarily have to be a perfect sphere, and elliptical or potato-shaped particles can also be used. Specifically, the particle shape has a ratio of the major axis diameter l to the minor axis diameter w (l/w) of 3 or less, preferably 1 to 2, and more preferably 1 to 1.5.
The dialkoxymagnesium may have an average particle size of 1 to 200 μm, preferably 5 to 150 μm. In the case of spherical dialkoxymagnesium, the average particle size is 1 to 100 μm, preferably 5 to 50 μm, and more preferably 10 to 40 μm.
As for the particle size, it is desirable to use one with a narrow particle size distribution with few fine and coarse particles. Specifically, the particles of 5 μm or less are 20% or less, preferably 10% or less. On the other hand, the particles of 100 μm or more are 10% or less, preferably 5% or less.
Furthermore, when the particle size distribution is expressed as ln(D90/D10) (where D90 is the particle size at 90% of the cumulative particle size, and D10 is the particle size at 10% of the cumulative particle size), it is 3 or less, and preferably 2 or less.

The manufacturing method of the above-mentioned spherical dialkoxymagnesium is exemplified in, for example, JP-A-58-41832, JP-A-62-51633, JP-A-3-74341, JP-A-4-368391, and JP-A-8-73388.

1-1-2. Titanium (A1a-2)
Any titanium compound can be used as the titanium source for the solid component (A1) according to the present invention. Representative examples include the compounds disclosed in JP-A-3-234707.
Regarding the valence of titanium, titanium compounds having any valence of tetravalent, trivalent, divalent, or zero can be used, but it is preferable to use tetravalent and trivalent titanium compounds, and more preferably tetravalent titanium compounds.

Specific examples of the tetravalent titanium compound include titanium halide compounds such as titanium tetrachloride, alkoxy titanium compounds such as tetrabutoxy titanium, condensation compounds of alkoxy titanium having a Ti-O-Ti bond such as tetrabutoxy titanium dimer (BuO) ₃ Ti-O-Ti(OBu) ₃ , and organometallic titanium compounds such as dicyclopentadienyl titanium dichloride. Among these, titanium tetrachloride and tetrabutoxy titanium are particularly preferred.
Specific examples of the trivalent titanium compound include titanium halide compounds such as titanium trichloride. Titanium trichloride may be a hydrogen-reduced type, a metallic aluminum-reduced type, a metallic titanium-reduced type, or an organoaluminum-reduced type, and may be any compound produced by any known method.
The titanium compounds may be used alone or in combination of two or more compounds. Also usable are mixtures of the titanium compounds, compounds whose average composition formula is a mixture of these compounds (e.g., compounds such as Ti(OBu) _{mCl4 -m} ; 0<m< ₄ ), and complexes with other compounds such as phthalates (e.g., compounds such as Ph( _CO2Bu ) _2.TiCl4 ).

1-1-3. Halogen (A1a-3)
The halogen used in the solid component (A1) according to the present invention may be fluorine, chlorine, bromine, iodine, or a mixture thereof, of which chlorine is particularly preferred.
The halogen is generally supplied from the titanium compound and/or magnesium compound, but can also be supplied from other compounds. Representative examples include halogenated silicon compounds such as silicon tetrachloride, halogenated aluminum compounds such as aluminum chloride, halogenated organic compounds such as 1,2-dichloroethane and benzyl chloride, halogenated borane compounds such as trichloroborane, halogenated phosphorus compounds such as phosphorus pentachloride, halogenated tungsten compounds such as tungsten hexachloride, and halogenated molybdenum compounds such as molybdenum pentachloride. These compounds can be used alone or in combination. Among these, silicon tetrachloride is particularly preferred.

1-1-4. Electron donor (A1a-4)
Representative examples of the electron donor (A1a-4) used in the solid component (A1) according to the present invention include the compounds disclosed in JP-A-2004-124090. In general, organic acids, inorganic acids and their derivatives (esters, acid anhydrides, acid halides, amides), ether compounds, ketone compounds, aldehyde compounds, alcohol compounds, amine compounds, etc. can be used, and the donor may be one or a mixture of two or more selected from the group consisting of organic acids, inorganic acids and their derivatives, ether compounds, and ketone compounds.

Examples of organic acid compounds that can be used as the electron donor (A1a-4) include aromatic polycarboxylic acid compounds typified by phthalic acid, aromatic carboxylic acid compounds typified by benzoic acid, aliphatic polycarboxylic acid compounds typified by malonic acid having one or two substituents at the 2-position, such as 2-n-butyl-malonic acid, and succinic acid having one or two substituents at the 2-position or one or more substituents at each of the 2-position and the 3-position, such as 2-n-butyl-succinic acid, aliphatic carboxylic acid compounds typified by propionic acid, and aromatic and aliphatic sulfonic acid compounds typified by benzenesulfonic acid and methanesulfonic acid.
These carboxylic acid compounds and sulfonic acid compounds may be aromatic or aliphatic and may have any number of unsaturated bonds at any position in the molecule, like maleic acid.

Examples of compounds derived from organic acids that can be used as the electron donor (A1a-4) include esters (carboxylate compounds), acid anhydrides, acid halides, and amides of the above organic acids.
The alcohol that is a component of the ester may be an aliphatic or aromatic alcohol. Among these alcohols, alcohols having an aliphatic free radical with 1 to 20 carbon atoms, such as an ethyl group, a butyl group, an isobutyl group, a heptyl group, an octyl group, or a dodecyl group, are preferred. More preferred are alcohols having an aliphatic free radical with 2 to 12 carbon atoms. In addition, alcohols having an alicyclic free radical, such as a cyclopentyl group, a cyclohexyl group, or a cycloheptyl group, may also be used.

The halogen that is a component of the acid halide may be fluorine, chlorine, bromine, iodine, etc. Among them, chlorine is most preferable. In the case of a polyhalide of a polyvalent organic acid, the multiple halogens may be the same or different.
In addition, as the amine that is a component of the amide, aliphatic and aromatic amines can be used. Among these amines, preferred examples include ammonia, aliphatic amines such as ethylamine and dibutylamine, and amines having an aromatic free radical in the molecule such as aniline and benzylamine.

Examples of inorganic acid compounds that can be used as the electron donor (A1a-4) include carbonic acid, phosphoric acid, silicic acid, sulfuric acid, and nitric acid.
As the derivative compound of these inorganic acids, it is preferable to use an ester, and specific examples thereof include tetraethoxysilane (ethyl silicate), tetrabutoxysilane (butyl silicate), and tributyl phosphate.

Examples of ether compounds that can be used as the electron donor (A1a-4) include aliphatic ether compounds such as dibutyl ether, aromatic ether compounds such as diphenyl ether, aliphatic polyvalent ether compounds such as 1,3-dimethoxypropane having one or two substituents at the 2-position, such as 2-isopropyl-2-isobutyl-1,3-dimethoxypropane and 2-isopropyl-2-isopentyl-1,3-dimethoxypropane, and polyvalent ether compounds having an aromatic free radical in the molecule, such as 9,9-bis(methoxymethyl)fluorene.

Examples of the ketone compound that can be used as the electron donor (A1a-4) include aliphatic ketone compounds such as methyl ethyl ketone, aromatic ketone compounds such as acetophenone, and polyhydric ketone compounds such as 2,2,4,6,6-pentamethyl-3,5-heptanedione.
Examples of the aldehyde compound that can be used as the electron donor (A1a-4) include aliphatic aldehyde compounds such as propionaldehyde, and aromatic aldehyde compounds such as benzaldehyde.
Further, examples of alcohol compounds that can be used as the electron donor (A1a-4) include aliphatic alcohol compounds such as butanol and 2-ethylhexanol, phenol derivative compounds such as phenol and cresol, and aliphatic or aromatic polyhydric alcohol compounds such as glycerin and 1,1'-bi-2-naphthol.

Examples of amine compounds that can be used as the electron donor (A1a-4) include aliphatic amine compounds such as diethylamine, nitrogen-containing alicyclic compounds such as 2,2,6,6-tetramethyl-piperidine, aromatic amine compounds such as aniline, polyvalent amine compounds such as 1,3-bis(dimethylamino)-2,2-dimethylpropane, and nitrogen-containing aromatic compounds.

Furthermore, as a compound that can be used as the electron donor (A1a-4), a compound containing the above-mentioned multiple functional groups in the same molecule can also be used. Examples of such compounds include carboxylate compounds having an alkoxy group in the molecule, such as ethyl acetate (2-ethoxyethyl) and ethyl 3-ethoxy-2-t-butylpropionate, ketoester compounds such as ethyl 2-benzoylbenzoate, ketoether compounds such as 1-t-butyl-2-methoxyethyl)methyl ketone, aminoether compounds such as N,N-dimethyl-2,2-dimethyl-3-methoxypropylamine, and halogenoether compounds such as epoxychloropropane.

These electron donors (A1a-4) can be used not only alone but also in combination of two or more compounds.
Among these, preferred are phthalic acid diester compounds typified by diethyl phthalate, dibutyl phthalate, diisobutyl phthalate, and diheptyl phthalate; phthalic acid dihalide compounds typified by phthaloyl dichloride; malonic acid ester compounds having one or two substituents at the 2-position such as 2-n-butyl-diethyl malonate; succinic acid ester compounds having one or two substituents at the 2-position or one or more substituents at each of the 2-position and the 3-position such as 2-n-butyl-diethyl succinate; aliphatic polyvalent ether compounds typified by 1,3-dimethoxypropane having one or two substituents at the 2-position such as 2-isopropyl-2-isobutyl-1,3-dimethoxypropane and 2-isopropyl-2-isopentyl-1,3-dimethoxypropane; and polyvalent ether compounds having an aromatic free radical in the molecule such as 9,9-bis(methoxymethyl)fluorene.
Among these, particularly preferred are organic acid ester compounds, acid halide compounds and ether compounds, and particularly preferred are those selected from the group consisting of phthalic acid diester compounds and phthalic acid dihalide compounds.
The ratio of the amounts of the components constituting the solid component (A1) used in the present invention may be any amount within a range that does not impair the effects of the present invention, but is generally preferably within the following ranges.

The amount of titanium compound (A1a-2) used is preferably in the range of 0.0001 to 1,000, more preferably in the range of 0.001 to 100, and particularly preferably in the range of 0.01 to 50, in terms of molar ratio (number of moles of titanium compound/number of moles of magnesium compound) relative to the amount of magnesium compound (A1a-1) used.

When using a compound that serves as a halogen source (i.e., (A1a-3)) other than the magnesium compound (A1a-1) and the titanium compound (A1a-2), the amount used is, regardless of whether the magnesium compound and the titanium compound each contain a halogen or not, preferably in a molar ratio (number of moles of compound that serves as a halogen source/number of moles of magnesium compound) in the range of 0.01 to 1,000, particularly preferably in a range of 0.1 to 100, relative to the amount of magnesium compound (A1a-1) used.

The amount of electron donor (A1a-4) used is preferably in the range of 0.001 to 10, particularly preferably 0.01 to 5, in terms of molar ratio (number of moles of electron donor/number of moles of magnesium compound) relative to the amount of magnesium compound (A1a-1) used.

The solid component (A1) according to the present invention can be obtained by contacting the above-mentioned constituent components in the above-mentioned ratios.
The contact conditions of the components must be such that oxygen is not present, but any conditions can be used as long as the effects of the present invention are not impaired. In general, the following conditions are preferred:
The contact temperature is about -50 to 200.degree. C., preferably 0 to 150.degree.
Examples of the contact method include a mechanical method using a rotating ball mill or a vibrating mill, and a method in which the mixture is contacted by stirring in the presence of an inert diluent.

In the preparation of the solid component (A1), washing with an inert solvent may be carried out intermediately and/or finally.
Preferred examples of the solvent include aliphatic hydrocarbon compounds such as heptane, aromatic hydrocarbon compounds such as toluene and xylene, and halogen-containing hydrocarbon compounds such as 1,2-dichloroethylene and chlorobenzene.

The solid component (A1) according to the present invention can be prepared by any method, but specific examples include the methods described below as (i) to (vii). However, the present invention is not limited in any way by the following examples.

(i) Co-grinding Method This is a method in which a halogen-containing magnesium compound, typically magnesium chloride, is co-grinded with a titanium compound to support the titanium compound on the magnesium compound. An electron donor may be co-grinded at the same time or in a separate step.
As the mechanical pulverization method, any pulverizer such as a rotary ball mill or a vibration mill can be used. Not only a dry pulverization method that does not use a solvent, but also a wet pulverization method in which pulverization is performed in the presence of an inert solvent can be used.

(ii) Heat Treatment Method This is a method in which a halogen-containing magnesium compound, typified by magnesium chloride, is stirred with a titanium compound in an inert solvent to carry out a contact treatment, thereby supporting the titanium compound on the magnesium compound. An electron donor may be contacted at the same time or in a separate step.
When a liquid compound such as titanium tetrachloride is used as the titanium compound, the contact treatment can be carried out without using an inert solvent.
If necessary, an optional component such as a silicon halide compound may be contacted simultaneously or in a separate step.
There is no particular restriction on the contact temperature, but it is often preferable to carry out the contact treatment at a relatively high temperature of about 90°C to 130°C.

(iii) Dissolution-precipitation method The dissolution-precipitation method is a method in which a halogen-containing magnesium compound, typified by magnesium chloride, is dissolved by contacting it with an electron donor, and the resulting solution is brought into contact with a precipitating agent to cause a precipitation reaction, thereby forming particles.
Examples of the electron donor used for dissolution include alcohol compounds, epoxy compounds, phosphate compounds, silicon compounds having an alkoxy group, titanium compounds having an alkoxy group, and ether compounds.
Examples of the precipitating agent include titanium halide compounds, silicon halide compounds, hydrogen chloride, halogen-containing hydrocarbon compounds, siloxane compounds having a Si-H bond (including polysiloxane compounds), aluminum compounds, and the like.
The method for bringing the dissolving solution into contact with the precipitating agent may be to add the precipitating agent to the dissolving solution, or to add the dissolving solution to the precipitating agent.
In either the dissolution or precipitation step, when no titanium compound is used, the particles formed by the precipitation reaction are further contacted with a titanium compound, thereby supporting the titanium compound on the magnesium compound.
If necessary, the particles formed by the above method may be contacted with optional components such as titanium halide compounds or silicon halide compounds, or with an electron donor, which may be different from or the same as that used for dissolution.
The order of contacting these optional components is not particularly limited, and they may be contacted as independent steps or may be contacted together during dissolution, precipitation and contact with titanium compounds.
An inert solvent may be present in any of the steps of dissolution, precipitation, and contact with an optional component.

(iv) Granulation method The granulation method is a method in which, like the dissolution-precipitation method, a halogen-containing magnesium compound, typically magnesium chloride, is dissolved by contacting it with an electron donor, and the resulting solution is granulated mainly by a physical method. Examples of the electron donor used for dissolution are the same as those in the dissolution-precipitation method.
Examples of granulation techniques include a method of dropping a high-temperature solution into a low-temperature inert solvent, a method of spraying a solution from a nozzle toward a high-temperature gas phase and drying it, and a method of spraying a solution from a nozzle toward a low-temperature gas phase and cooling it.
The particles formed by granulation are brought into contact with a titanium compound, thereby supporting the titanium compound on the magnesium compound.
If necessary, the mixture may be contacted with optional components such as halogenated silicon compounds and electron donors. In this case, the electron donor may be different from or the same as that used in the dissolution.
The order of contacting these optional components is not particularly limited, and they may be contacted as independent steps or may be contacted together when dissolving or contacting with the titanium compound.
An inert solvent may be present in any of the steps of dissolution, contact with titanium compounds, and contact with optional components.

(v) Method for Halogenating Magnesium (Mg) Compounds The method for halogenating magnesium (Mg) compounds is a method in which a halogen-free magnesium compound is brought into contact with a halogenating agent to halogenate it. An electron donor may be contacted simultaneously with the magnesium compound or in a separate step.
Examples of halogen-free magnesium compounds include dialkoxymagnesium compounds, magnesium oxide, magnesium carbonate, magnesium salts of fatty acids, and the like.
When using dialkoxymagnesium compounds, those prepared in situ by reacting metallic magnesium with alcohol can also be used. When using this preparation method, particles are generally formed by granulation or the like at the stage of the starting material, the magnesium compound not containing halogen.
Examples of the halogenating agent include titanium halide compounds, silicon halide compounds, and phosphorus halide compounds.
When a halogenating agent is not a titanium halide compound, the halogen-containing magnesium compound formed by halogenation is further contacted with a titanium compound to support the titanium compound on the magnesium compound.
If necessary, the grains formed by the above method may be contacted with an optional component such as a titanium halide compound or a silicon halide compound, or may be contacted with an electron donor.
The order of contacting these optional components is not particularly limited, and they may be contacted as independent steps, or they may be contacted together with the halogenation of a halogen-free magnesium compound or the contact with a titanium compound.
An inert solvent may be present in either step of contacting with the titanium halide compound or the step of contacting with the optional component.

(vi) Precipitation from an organomagnesium compound This is a method of contacting a precipitating agent with a solution of an organomagnesium compound, such as a Grignard reagent represented by butylmagnesium chloride, or a dialkylmagnesium compound. An electron donor may be contacted simultaneously or in a separate step.
Examples of the precipitating agent include titanium compounds, silicon compounds, hydrogen chloride, and the like.
When a titanium compound is not used as the precipitating agent, the particles formed by the precipitation reaction are further contacted with a titanium compound, thereby supporting the titanium compound on the magnesium compound.
If necessary, the grains formed by the above method may be contacted with an optional component such as a titanium halide compound or a silicon halide compound, or may be contacted with an electron donor.
There is no particular restriction on the order of contacting these optional components, and they may be contacted as independent steps or together with the precipitation or contact with the titanium compound.
An inert solvent may be present in any of the steps of precipitation, contact with titanium compounds, and contact with optional components.

(vii) Impregnation Method This method comprises impregnating an inorganic compound support or an organic compound support with a solution of an organomagnesium compound or a solution in which a magnesium compound is dissolved with an electron donor.
Examples of organomagnesium compounds are the same as those in the example of the precipitation method from an organomagnesium compound. The magnesium compound used for dissolving the magnesium compound may or may not contain a halogen, and examples of electron donors are the same as those in the example of the dissolution-precipitation method.
Examples of inorganic carriers include silica, alumina, and magnesia.
Examples of organic carriers include polyethylene, polypropylene, and polystyrene.
After the impregnation treatment, the carrier particles are subjected to a chemical reaction with a precipitating agent or a physical treatment such as drying to precipitate and immobilize the magnesium compound.
Examples of the precipitating agent are the same as those in the dissolution-precipitation method.
When a titanium compound is not used as a precipitating agent, the thus-formed particles are further contacted with a titanium compound to support the titanium compound on the magnesium compound. If necessary, the thus-formed particles may be further contacted with an optional component such as a titanium halide compound or a silicon halide compound, or may be contacted with an electron donor.
The order of contacting these optional components is not particularly limited, and they may be contacted as independent steps, or they may be contacted together during impregnation, precipitation, drying, and contact with titanium compounds. In addition, an inert solvent may be present in any of the steps of impregnation, precipitation, contact with titanium compounds, and contact with optional components.

(viii) Composite method The above methods (i) to (vii) can also be used in combination. Examples of combinations include "a method of co-grinding magnesium chloride with an electron donor, followed by heat treatment with titanium halide compounds", "a method of co-grinding a magnesium chloride compound with an electron donor, dissolving it with another electron donor, and then precipitating it with a precipitating agent", "a method of dissolving a dialkoxy magnesium compound with an electron donor, contacting it with titanium halide compounds to precipitate and simultaneously halogenate the magnesium compound", and "a method of contacting a dialkoxy magnesium compound with carbon dioxide to generate and simultaneously dissolve magnesium carbonate compounds, impregnating silica with the resulting solution, then contacting it with hydrogen chloride to halogenate the magnesium compound, simultaneously precipitating and fixing it, and further contacting it with titanium halide compounds to support the titanium compound".

1-1-5. Prepolymerization of Solid Component (A1) In the present invention, the solid component (A1) may be prepolymerized using a polymerization monomer in the presence of an organoaluminum compound as a co-catalyst.
As the polymerization monomer in the preliminary polymerization, the compounds disclosed in JP-A-2004-124090 and the like can be used, and specific examples thereof include ethylene, propylene, and α-olefins having 4 to 22 carbon atoms and represented by the general formula (c) described later.

The reaction conditions of the solid component (A1) with the above-mentioned polymerizable monomers can be any conditions within a range that does not impair the effects of the present invention. In general, the following ranges are preferred.
The amount of the prepolymerized monomer per gram of the solid component (A1) is in the range of 0.001 to 100 g, preferably 0.1 to 50 g, and more preferably 0.5 to 10 g.
The reaction temperature during the preliminary polymerization is −150 to 150° C., preferably 0 to 100° C. The reaction temperature during the preliminary polymerization is desirably lower than the polymerization temperature during the main polymerization.
The reaction is generally preferably carried out under stirring, and an inert solvent such as hexane or heptane may be present.
The prepolymerization may be carried out several times, and the polymerization monomers used in the prepolymerization may be the same or different. After the prepolymerization, washing with an inert solvent such as hexane or heptane may be carried out.
The material and amount of the organoaluminum compound used may be the same as those described below for component (A4).

1-2. Silane compound having an alkenyl group (A2)
As the silane compound (A2) having an alkenyl group used in the present invention, compounds disclosed in JP-A-2-34707, JP-A-2003-292522, JP-A-2006-169283, and JP-A-2011-74360, and the like can be used.
In general, it is desirable to use a compound represented by the following general formula (a).
SiR ⁶ _n R ⁷ _4-n... (a)
(Here, ^R6 is an alkenyl group, ^R7 is a hydrogen atom, a halogen atom, an alkyl group or an alkoxy group, and n is 1≦n≦4. When 1≦n≦2, ^R7s may be linked together to form a cyclic structure.)

In the general formula (a), R ⁶ represents an alkenyl group, preferably a vinyl group, an allyl group, or a 3-butenyl group, and more preferably a vinyl group or an allyl group. When the value of n is 2 or more, the multiple R ^6s may be the same or different.

In addition, in the general formula (a), ^R7 represents a hydrogen atom, a halogen, an alkyl group, or an alkoxy group.
Examples of halogen usable as ^R7 include fluorine, chlorine, bromine, and iodine.
Furthermore, when ^R7 is an alkyl group, it is generally an alkyl group having 1 to 20 carbon atoms, preferably 1 to 12 carbon atoms. Specific examples of the alkyl group that can be used as ^R7 include methyl, ethyl, propyl, i-propyl, i-butyl, s-butyl, t-butyl, thexyl, cyclopentyl, and cyclohexyl groups.
When R ⁷ is an alkoxy group, it is generally an alkoxy group having 1 to 20 carbon atoms, preferably 1 to 12 carbon atoms. Specific examples of the alkoxy group that can be used as R ⁷ include a methoxy group, an ethoxy group, a propoxy group, an i-propoxy group, an i-butoxy group, an s-butoxy group, and a t-butoxy group. When the value of n is 2 or less, multiple R ^7s may be the same or different. When 1≦n≦2, R ^7s may be linked together to form a cyclic structure.

Specific examples of the silane compound (A2) having an alkenyl group include vinyl silane, methyl vinyl silane, dimethyl vinyl silane, trimethyl vinyl silane, trichloro vinyl silane, dichloro methyl vinyl silane, chloro dimethyl vinyl silane, chloro methyl vinyl silane, triethyl vinyl silane, chloro diethyl vinyl silane, dichloro ethyl vinyl silane, dimethyl ethyl vinyl silane, diethyl methyl vinyl silane, tripentyl vinyl silane, triphenyl vinyl silane, diphenyl methyl vinyl silane, dimethyl phenyl vinyl silane, CH ₂ ═CH—Si(CH ₃ ) ₂ (C ₆ H ₄ CH ₃ ), (CH ₂ ═CH)(CH ₃ ) ₂ Si—O—Si(CH ₃ ) ₂ (CH═CH ₂ ), divinyl silane, dichlorodivinyl silane, dimethyldivinyl silane, diphenyldivinyl silane, allyltrimethyl silane, allyltriethyl silane, allyltrivinyl silane, allylmethyldivinyl silane, allyldimethylvinyl silane, allylmethyldichlorosilane, allyltrichlorosilane, allyltribromosilane, diallyldimethylsilane, diallyldiethylsilane, diallyldivinyl silane, diallylmethylvinyl silane, diallylmethylchlorosilane, diallyldichlorosilane, diallyldibromosilane, triallylmethylsilane, triallyethylsilane, triallylvinylsilane, triallylchlorosilane, triallylbromosilane, tetraallylsilane, di-3-butenyldimethylsilane, di-3-butenylsilanediethylsilane, di-3-butenylsilane Examples of the silane include divinylsilane, di-3-butenylsilane methylvinylsilane, di-3-butenylsilane methylchlorosilane, di-3-butenylsilane dichlorosilane, tri-3-butenylsilane ethylsilane, tri-3-butenylsilane vinylsilane, tri-3-butenylsilane chlorosilane, tri-3-butenylsilane bromosilane, tetra-3-butenylsilane, 1-methyl-1-vinylsilacyclobutane, 1-methyl-1-vinylsilacyclopentane, 1-methyl-1-vinylsilacyclohexane, 1,1-divinylsilacyclopentane, 1,1-divinylsilacyclohexane, 1-chloro-1-vinylsilacyclopentane, 1-chloro-1-vinylsilacyclohexane, 1-allyl-1-methylsilacyclopentane, and 1-allyl-1-methylsilacyclohexane.
Of these, vinylsilane compounds are preferred, with trimethylvinylsilane, trichlorovinylsilane, dimethyldivinylsilane and 1-methyl-1-vinylsilacyclopentane being particularly preferred.

The amount of the silane compound (A2) having an alkenyl group may be any amount within a range that does not impair the effects of the present invention, but is generally preferably within the following range.
The amount of the silane compound (A2) having an alkenyl group used is preferably in the range of 0.001 to 1,000, particularly preferably 0.01 to 100, in terms of the molar ratio to the titanium component constituting the solid component (A1) (the number of moles of the silane compound (A2) having an alkenyl group/the number of moles of titanium atoms in the solid component (A1)).

The silane compound (A2) having an alkenyl group used in the present invention usually has a greater steric hindrance than an α-olefin monomer, and cannot be polymerized with a Ziegler-Natta catalyst.
However, due to the presence of an organic silyl group with very strong electron-donating properties, the charge density of the carbon-carbon double bond is very high, and coordination to the titanium atom, which is the active center, is thought to be very fast.
Therefore, by coordinating and complexing the Lewis acid sites on the magnesium compound carrier, the silane compound having an alkenyl group can suppress the extraction of the titanium compound into the solvent, and is expected to prevent the over-reduction of titanium atoms by organoaluminum compounds and the deactivation of active sites due to impurities.

1-3. Alkoxysilane compound (A3)
The alkoxysilane compound (A3) used in the production method of the present invention is different from the above-mentioned silane compound (A2) having an alkenyl group.
In the production method of the present invention, the component (A3) may be a silicon compound represented by the following general formula (2).
^R3R4mSi ( ^OR5 _{) n} ...( ² )
(In the general formula (2), ^R3 represents a hydrocarbon group or a heteroatom-containing hydrocarbon group. ^R4 represents hydrogen, a halogen, a hydrocarbon group or a heteroatom-containing hydrocarbon group. ^R5 represents a hydrocarbon group. m and n each represent an integer such that 0≦m≦2, 1≦n≦3, or m+n=3.)

In formula (2), ^R3 represents a hydrocarbon group or a heteroatom-containing hydrocarbon group.
When ^R3 is a hydrocarbon group, it is a hydrocarbon group excluding an alkenyl group.
The hydrocarbon group that can be used as R ³ generally has 1 to 20 carbon atoms, preferably 3 to 10 carbon atoms. Specific examples of the hydrocarbon group that can be used as R ³ include linear aliphatic hydrocarbon groups such as n-propyl groups, branched aliphatic hydrocarbon groups such as i-propyl groups and t-butyl groups, alicyclic hydrocarbon groups such as cyclopentyl groups and cyclohexyl groups, and aromatic hydrocarbon groups such as phenyl groups. It is more preferable to use a branched aliphatic hydrocarbon group or an alicyclic hydrocarbon group as R ³ , and it is particularly preferable to use an i-propyl group, an i-butyl group, a t-butyl group, a thexyl group, a cyclopentyl group, a cyclohexyl group, or the like.
When ^R3 is a heteroatom-containing hydrocarbon group, the heteroatom is preferably selected from nitrogen, oxygen, sulfur, phosphorus, or silicon, and is particularly preferably nitrogen or oxygen.
The backbone structure of the heteroatom-containing hydrocarbon group of ^R3 is preferably selected from the examples given when ^R3 is a hydrocarbon group, with N,N-diethylamino, quinolino, isoquinolino, and the like being particularly preferred.

In the formula, R ⁴ represents a hydrogen atom, a halogen, a hydrocarbon group, or a heteroatom-containing hydrocarbon group.
Examples of halogen usable as ^R4 include fluorine, chlorine, bromine, and iodine.
When ^R4 is a hydrocarbon group, it is a hydrocarbon group excluding an alkenyl group.
The hydrocarbon group that can be used as R ⁴ generally has 1 to 20 carbon atoms, and preferably has 1 to 10 carbon atoms. Specific examples of the hydrocarbon group that can be used as R ⁴ include linear aliphatic hydrocarbon groups such as methyl and ethyl groups, branched aliphatic hydrocarbon groups such as i-propyl and t-butyl groups, alicyclic hydrocarbon groups such as cyclopentyl and cyclohexyl groups, and aromatic hydrocarbon groups such as phenyl groups. Of these, it is desirable to use methyl, ethyl, propyl, i-propyl, i-butyl, s-butyl, t-butyl, thexyl, cyclopentyl, cyclohexyl, and the like.
When ^R4 is a heteroatom-containing hydrocarbon group, it is preferable to select it from the examples given when ^R3 is a heteroatom-containing hydrocarbon group, and particularly preferable are an N,N-diethylamino group, a quinolino group, an isoquinolino group, and the like.
Furthermore, regardless of the value of m, ^R4 may be the same as or different from ^R3 .

In the formula, ^R5 represents a hydrocarbon group. The hydrocarbon group that can be used as ^R5 generally has 1 to 20 carbon atoms, preferably 1 to 10 carbon atoms, and more preferably 1 to 5 carbon atoms.
Specific examples of the hydrocarbon group that can be used as ^R5 include linear aliphatic hydrocarbon groups such as methyl and ethyl groups, and branched aliphatic hydrocarbon groups such as i-propyl and t-butyl groups. Of these, methyl and ethyl groups are most preferred. When the value of n is 2 or more, multiple ^R5s may be the same or different.

Preferred examples of the alkoxysilane compound (A3) that can be used in the present invention include t-butylmethyldimethoxysilane, t-butylmethyldiethoxysilane, t-butylethyldimethoxysilane, t-butyl-n-propyldimethoxysilane, cyclohexylmethyldimethoxysilane, cyclohexylethyldimethoxysilane, dicyclopentyldimethoxysilane, diisopropyldimethoxysilane, diisobutyldimethoxysilane, isobutylisopropyldimethoxysilane, n-propylmethyldimethoxysilane, t-butyltriethoxysilane, bis(diethylamino)dimethoxysilane, diethylaminotriethoxysilanemethoxysilane, and bisperhydroisoquinolinodimethoxysilane.
These alkoxysilane compounds can be used not only alone but also in combination of two or more compounds.

The amount ratio of the alkoxysilane compound (A3) used may be any amount within a range that does not impair the effects of the present invention, but is generally preferably within the following range.
The amount of the alkoxysilane compound (A3) used is preferably in the range of 0.01 to 1,000, particularly preferably 0.1 to 100, in terms of the molar ratio to the titanium component constituting the solid component (A1) (the number of moles of alkoxysilane compound (A3)/the number of moles of titanium atoms in the solid component (A1)).

The alkoxysilane compound (A3) used in the present invention is thought to coordinate near titanium atoms that can become active sites, and control the catalytic performance, such as the catalytic activity of the active sites and the regularity of the polymer.

1-4. Organoaluminum compound (A4)
As the organoaluminum compound (A4) used in the present invention, the compounds disclosed in JP-A-2004-124090 and the like can be used. In general, it is desirable to use a compound represented by the following general formula (b).
R ⁸ _a AlX _b (OR ⁹ ) _c ...(b)
(In the general formula (b), ^R8 represents a hydrocarbon group. X represents a halogen or a hydrogen atom. ^R9 represents a hydrocarbon group or a bridging group by Al. a≧1, 0≦b≦2, 0≦c≦2, and a+b+c=3.)
In general formula (b), ^R8 is a hydrocarbon group, preferably having 1 to 10 carbon atoms, more preferably 1 to 8 carbon atoms, and particularly preferably 1 to 6 carbon atoms. Specific examples of ^R8 include a methyl group, an ethyl group, a propyl group, a butyl group, an isobutyl group, a hexyl group, and an octyl group. Of these, a methyl group, an ethyl group, and an isobutyl group are most preferred.
In the general formula (b), X is a halogen or a hydrogen atom. Examples of halogen usable as X include fluorine, chlorine, bromine, and iodine. Among these, chlorine is particularly preferred.
In the general formula (b), ^R9 is a hydrocarbon group or a crosslinking group based on Al. When ^R9 is a hydrocarbon group, ^it can be selected from the same group as the examples of the hydrocarbon group of ^R8 . In addition, alumoxane compounds such as methylalumoxane can also be used as the organoaluminum compound (A4), and in that case, ^R9 represents a crosslinking group based on Al.

Examples of compounds that can be used as the organoaluminum compound (A4) include trimethylaluminum, triethylaluminum, triisobutylaluminum, trioctylaluminum, diethylaluminum chloride, ethylaluminum chloride, diethylaluminum ethoxide, and methylalumoxane.
Of these, triethylaluminum and triisobutylaluminum are preferred.
The organoaluminum compound (A4) may be used not only as a single compound, but also as a combination of two or more compounds.

The amount of the organoaluminum compound (A4) used may be any amount within a range that does not impair the effects of the present invention, but is generally preferably within the following range.
The amount of the organoaluminum compound (A4) used is preferably in the range of 0.1 to 100, particularly preferably 1 to 50, in terms of the molar ratio (number of moles of aluminum atoms/number of moles of titanium atoms in solid component (A1)) to the titanium component constituting solid component (A1).

The organoaluminum compound (A4) used in the present invention is used mainly for the purpose of efficiently supporting the alkoxysilane compound (A3) in the solid catalyst component (A).
Therefore, they are distinguished from organoaluminum compounds used as co-catalysts in the polymerization reaction during the preliminary polymerization or main polymerization, as their main purpose is different.

1-5. Method for preparing solid catalyst component (A) In the production method of the present invention, the solid catalyst component (A) may be prepared by contacting the solid component (A1) with a silane compound (A2) having an alkenyl group, an alkoxysilane compound (A3), and an organoaluminum compound (A4) at a predetermined temperature.
In the production method of the present invention, the contact treatment may be carried out multiple times during the preparation of the solid catalyst component (A).
When the contact treatment is carried out multiple times, the alkenyl group-containing silane compound (A2), the alkoxysilane compound (A3), and the organoaluminum compound (A4) used in each of the multiple contact treatments may be the same or different.
The solid catalyst component (A) used in the present invention can be obtained by contacting the above-mentioned constituent components in the above-mentioned ratios.
Furthermore, the range of the amount of each component used was shown above, but this is the amount used per contact, and from the second time onwards, the components may be contacted any number of times as long as the amount used per contact is within the range of the amount used above.

The contact conditions for each component of the solid catalyst component (A) must be such that oxygen is not present, but any conditions can be used as long as they do not impair the effects of the present invention. In general, the following conditions are preferred.

Examples of the contact method include a mechanical method using a rotating ball mill or a vibration mill, and a method of contacting by stirring in the presence of an inert diluent, etc. It is preferable to use the method of contacting by stirring in the presence of an inert diluent.
If the contact temperature is too low, the reaction does not proceed, and a large amount of the electron donor (A1a-4) remains, which is thought to cause a deterioration in catalytic performance such as stereoregularity. On the other hand, if the contact temperature is too high, it is thought that the active site itself may be altered, which may significantly deteriorate catalytic performance such as activity and stereoregularity. The contact temperature may be 50 to 110°C, 50 to 100°C, 50 to 95°C, 60 to 90°C, or 70 to 90°C.

In the contact treatment, any procedure can be used for contacting the solid component (A1), the silane compound having an alkenyl group (A2), the alkoxysilane compound (A3), and the organoaluminum compound (A4). Specific examples include the following procedures (i) to (iv), among which procedures (i) and (ii) are preferred.
Step (i): A method in which a solid component (A1) is contacted with a silane compound (A2) having an alkenyl group, then with an alkoxysilane compound (A3), and thereafter with an organoaluminum compound (A4).
Procedure (ii): A method in which a solid component (A1) is contacted with a silane compound (A2) having an alkenyl group and an alkoxysilane compound (A3), and then with an organoaluminum compound (A4).
Procedure (iii): A method in which a solid component (A1) is contacted with an alkoxysilane compound (A3), then with a silane compound (A2) having an alkenyl group, and finally with an organoaluminum compound (A4).
Procedure (iv): All compounds are contacted simultaneously.

When preparing the solid catalyst component (A), washing with an inert solvent may be performed in the middle and/or at the end. Examples of preferred solvents used for washing include aliphatic hydrocarbon compounds such as heptane, aromatic hydrocarbon compounds such as toluene and xylene, and halogen-containing hydrocarbon compounds such as 1,2-dichloroethylene and chlorobenzene.

1-6. Prepolymerization of solid catalyst component (A) The solid catalyst component (A) obtained in step (I) may be prepolymerized with a polymerization monomer in the presence of an organoaluminum compound as a polymerization reaction cocatalyst before being used in the main polymerization. By forming a small amount of polymer around the catalyst in advance prior to the polymerization process, the catalyst becomes more uniform and the amount of fine powder generated can be suppressed.
As the polymerization monomer in the preliminary polymerization, the compounds disclosed in JP-A-2004-124090 and the like can be used, and examples thereof include ethylene, propylene, and α-olefins having 4 to 22 carbon atoms and represented by the general formula (c) described below.

When a prepolymerized solid catalyst component (A) is used, the prepolymerization can be carried out in any procedure in the preparation procedure. For example, the solid component (A1) can be prepolymerized and then contacted with the components (A2) to (A4). Furthermore, prepolymerization can be carried out at the same time that the solid component (A1) is contacted with the components (A2) to (A4).

The reaction conditions for the solid catalyst component (A) and the above-mentioned polymerization monomers can be any conditions within the range that does not impair the effects of the present invention. In general, the following ranges are preferred.
The amount of the prepolymerized monomer per gram of the solid catalyst component (A) is in the range of 0.001 to 100 g, preferably 0.1 to 50 g, and more preferably 0.5 to 10 g.
The reaction temperature during the preliminary polymerization is −150 to 150° C., preferably 0 to 100° C. The reaction temperature during the preliminary polymerization is desirably lower than the polymerization temperature during the main polymerization.
The reaction is generally preferably carried out under stirring, and an inert solvent such as hexane or heptane may be present.
The prepolymerization may be carried out several times, and the monomers used for polymerization may be the same or different. After the prepolymerization, washing may be carried out with an inert solvent such as hexane or heptane.

1-7. Solid catalyst component (A)
The solid catalyst component (A) obtained in step (I) is composed of magnesium (A1a-1), titanium (A1a-2), a halogen (A1a-3), an electron donor (A1a-4) and an alkoxysilane compound (A3 ).
The materials of magnesium (A1a-1), titanium (A1a-2), halogen (A1a-3), electron donor (A1a-4) and alkoxysilane compound (A3) contained in the solid catalyst component (A) are the same as those described above. Therefore, the description here is omitted.

The content of the electron donor (A1a-4) in the solid catalyst component (A) may be 40 μmol or less, and preferably 37 μmol or less, per unit mass of the solid catalyst component (A).
If the electron donor (A1a-4) remains in the solid catalyst component (A), it is considered that there is a possibility that the catalytic performance such as stereoregularity may be deteriorated. Therefore, the content thereof is preferably as small as possible. The lower limit of the content of the electron donor (A1a-4) in the solid catalyst component (A) is preferably either completely removed after preparation of the solid catalyst component (A) to be 0 or as close to 0 as possible.

2. Step (II)
The step (II) is a step of contacting the solid catalyst component (A) with the following components (B) and (C) in the presence of a polymerizable monomer, thereby polymerizing the polymerizable monomer.
Component (B): organoaluminum compound Component (C): unsaturated cyclic ether compound

2-1. Organoaluminum compound (B)
The organoaluminum compound (B) acts mainly as a co-catalyst in the polymerization treatment, and also acts as a scavenger for removing water and other impurities from the system.
As the organoaluminum compound (B) that can be used in the present invention, the compounds disclosed in JP-A-2004-124090 and the like can be used.
Preferably, it can be selected from the same group as the examples of the organoaluminum compound (A4) which is a component in preparing the solid catalyst component (A).
The organoaluminum compound (B) may be the same as or different from the organoaluminum compound (A4) which can be used in preparing the solid catalyst component (A).
The organoaluminum compound (B) may be used not only as a single compound, but also as a combination of two or more compounds.
The amount of the organoaluminum compound (B) used may be any amount within a range that does not impair the effects of the present invention, but is generally preferably within the following range.
The amount of the organoaluminum compound (B) used is preferably in the range of 1 to 5,000, particularly preferably 10 to 500, in terms of the molar ratio to the titanium component constituting the solid catalyst component (A) (the number of moles of the organoaluminum compound (B)/the number of moles of titanium atoms in the solid catalyst component (A)).

2-2. Unsaturated cyclic ether compound (C)
It is presumed that the unsaturated cyclic ether compound (C) used in the present invention reacts preferentially with titanium atoms, which are active sites that generate amorphous components, and poisons and deactivates them, due to its structural size and the electronic state of the oxygen atom. In particular, in the unsaturated cyclic ether, the dipole moment is caused by the difference in electronegativity of the carbon-oxygen σ bond, as well as the bias of π electrons due to the resonance of the unshared electron pair. Since these two act in the opposite direction and cancel each other out, the dipole moment tends to be small. For this reason, it is presumed that the electron density of the oxygen atom of the unsaturated cyclic ether is smaller than that of the non-cyclic ether and the saturated cyclic ether, and as a result, it becomes easier to react preferentially with the active sites that generate amorphous components.
The unsaturated cyclic ether compound (C) used in the present invention includes an unsaturated cyclic ether compound containing at least one oxygen atom.Specific examples of the unsaturated cyclic ether compound include furans, dioxenes, pyrans, and oxepins.
As the unsaturated cyclic ether compound (C) used in the present invention, furans are particularly preferred, and they can be selected from compounds represented by the following general formula (1).

(In general formula (1), ^R1 and ^R2 are hydrogen atoms or hydrocarbon groups, and ^R1 and ^R2 may be the same or different.)
In general formula (1), R ¹ and R ² are a hydrogen atom or a hydrocarbon group. When R ¹ and R ² are a hydrocarbon group, they are preferably a structurally small bulky substituent such as an alkyl group or a cycloalkyl group having 1 to 10 carbon atoms, more preferably 1 to 5 carbon atoms. Specific examples include a hydrogen atom, a methyl group, an ethyl group, a vinyl group, an allyl group, an n-propyl group, an i-propyl group, an n-butyl group, an i-butyl group, a t-butyl group, an n-hexyl group, an i-hexyl group, a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, and a cyclooctyl group, and in particular, a hydrogen atom, a methyl group, and an ethyl group are preferred.
Specific examples of the compound include furan compounds such as furan, 2-methylfuran, 2-ethylfuran, 2-i-propylfuran, 2,5-dimethylfuran, 2,5-diethylfuran, 2,5-diisopropylfuran, etc. Among these furan compounds, furan, 2-methylfuran, 2-ethylfuran, 2,5-dimethylfuran, and 2,5-diethylfuran are preferred, and furan, 2-methylfuran, 2,5-dimethylfuran, and 2,5-diethylfuran are particularly preferred.
Two or more of these furan compounds can also be used.

The amount ratio of the unsaturated cyclic ether compound (C) used may be any amount within a range that does not impair the effects of the present invention, but is generally preferably within the following range.
The amount of the unsaturated cyclic ether compound (C) used is, in terms of a molar ratio to the organoaluminum compound (B) (the number of moles of the unsaturated cyclic ether compound (C)/the number of moles of the organoaluminum compound (B)), within the range of 0.05 to 2.0, preferably 0.1 to 1.5, and more preferably 0.20 to 1.0.

2-3. Other compounds As long as the effects of the present invention are not impaired, components other than the above-mentioned organoaluminum compound (B) and unsaturated cyclic ether compound (C) can be used during polymerization of the polymerization monomer. For example, by using a compound having a C(=O)N bond in the molecule disclosed in JP-A-2004-124090 or a sulfite ester compound disclosed in JP-A-2006-225449, the generation of amorphous components such as CXS can be suppressed. In this case, preferred examples include tetramethylurea, 1,3-dimethyl-2-imidazolidinone, 1-ethyl-2-pyrrolidinone, dimethyl sulfite, and diethyl sulfite.
As disclosed in Japanese Patent Application Laid-Open No. 8-66710, an organometallic compound having a metal atom other than aluminum, such as diethylzinc, can also be used.
The amount of the compound having a C(═O)N bond in the molecule, the sulfite ester compound and diethylzinc used is preferably in the range of 0.001 to 1,000, particularly preferably 0.05 to 500, in terms of molar ratio to the titanium component constituting the solid catalyst component (A).

2-4. Polymerizable Monomers In the present invention, the polymerizable monomers include ethylene, propylene, α-olefins having 4 to 22 carbon atoms represented by the following general formula (c), dienes, and styrenes, and at least propylene is included.
R ¹⁰ -CH=CH ₂ ...(c)
(In general formula (c), R ¹⁰ is a hydrocarbon group having 2 to 20 carbon atoms, which may have a branched group.)
Specific examples of the α-olefin having 4 to 22 carbon atoms include butene-1, pentene-1, hexene-1, and 4-methylpentene-1.
The polymerization monomer used in the polymerization in the present invention may be only propylene, or may be a combination of two types of propylene and ethylene, or may be a combination of two or more types of propylene and an α-olefin having 4 to 22 carbon atoms and represented by the above general formula (c).

2-5. Production of Propylene-Based Polymer The propylene-based polymer of the present invention can be produced in the step (II) by contacting the solid catalyst component (A) with the following components (B) and (C) in the presence of a polymerization monomer, thereby polymerizing the polymerization monomer.
A polymerization catalyst containing the solid catalyst component (A), the component (B) and the component (C) is obtained by contacting the solid catalyst component (A), the component (B) and the component (C) in the presence of a polymerization monomer. The polymerization catalyst can be used to homopolymerize propylene or copolymerize propylene with a comonomer other than propylene, such as ethylene or an α-olefin having 4 to 22 carbon atoms, to produce a propylene-based polymer.

2-6. Preparation of polymerization catalyst The contact conditions of the solid catalyst component (A), component (B) and component (C) must be such that oxygen is not present in the presence of the polymerization monomer, but any conditions can be used as long as they do not impair the effects of the present invention. In general, the following conditions are preferred.
Specific examples include the following steps (i) to (ii).
Step (i): A method in which components (B) and (C) are simultaneously contacted in the presence of a polymerization monomer in an apparatus having a stirring function and a temperature control function, and then a solid catalyst component (A) is contacted.
Procedure (ii): A method in which all of the compounds are contacted simultaneously in an apparatus having stirring and temperature control functions.
The contact temperature may be any of the temperatures exemplified as the polymerization temperature of the polymerizable monomer described below.
As the device having the stirring function and the temperature control function, a conventionally known device can be adopted.

2-7. Polymerization Treatment of Polymerizable Monomers Polymerization of the polymerizable monomers may be carried out by slurry polymerization using a hydrocarbon solvent, liquid phase solventless polymerization using substantially no solvent, or gas phase polymerization.
In the case of slurry polymerization, a hydrocarbon solvent such as pentane, hexane, heptane, or cyclohexane is used as the polymerization solvent.
The polymerization method employed may be any method such as continuous polymerization, batch polymerization or multi-stage polymerization.
The polymerization temperature is usually about 30 to 200° C., preferably 50 to 150° C., and hydrogen may be used as a molecular weight regulator.
The polymerization of the polymerization monomer can be carried out not only as homopolymerization of propylene, but also as random copolymerization with a monomer copolymerizable with propylene, such as ethylene, an α-olefin having 4 to 22 carbon atoms represented by the above general formula (c), dienes, and styrenes.
It is also possible to carry out block copolymerization in which propylene is homopolymerized in the first stage and then randomly copolymerized in the second stage.
The copolymerizable monomers can be used in amounts up to 15% by weight in random copolymerizations and up to 50% by weight in block copolymerizations.
Among these, homopolymerization and block copolymerization of propylene are preferred, and in particular, homopolymerization of propylene and block copolymerization in which the first stage is homopolymerization of propylene are most preferred.

3. Propylene-Based Polymer The index of the propylene-based polymer polymerized according to the present invention is not particularly limited, and can be appropriately adjusted according to various applications.

3-1. MFR (g/10 min)
The MFR of the propylene polymer is preferably within the range of 0.01 to 10,000 g/10 min, and particularly preferably within the range of 0.1 to 1,000 g/10 min.

3-2. Melting point (℃)
The propylene polymer obtained by the production method of the present invention preferably has high stereoregularity.
The degree of stereoregularity of a propylene-based polymer can be evaluated by measuring the melting point.
The propylene polymer obtained by the production method of the present invention preferably has a melting point of 162.8°C or higher and 166.0°C or lower.
If the melting point is within the above range, the propylene-based polymer has a desired rigidity.

3-3.40℃ soluble content (mass%)
The propylene polymer produced by the present invention is characterized by an extremely small amount of amorphous components, high stereoregularity, and good odor and color.
The preferred range of the 40°C soluble content as the amorphous component of a propylene-based polymer generally varies depending on the application. For example, in applications where hard molded articles are preferred, such as general injection applications, in the case of polypropylene, The upper limit of the 40° C. soluble matter is preferably less than 1.3 mass %.

The propylene polymer produced by the present invention has an extremely small amount of amorphous components and a high stereoregularity, and therefore has high density, high rigidity and high heat resistance, and other excellent properties.
In addition, the propylene-based polymer can be produced in a high yield and can be suitably used in industrial materials such as automobile parts and home appliance parts that require high rigidity and high heat resistance, and in packaging materials and other applications because the propylene-based polymer is less sticky.

The present invention will be described in more detail below using examples, but the present invention is not limited to these examples. The measurement methods for each physical property value in the present invention are shown below.

(1) Titanium content:
The sample was accurately weighed, hydrolyzed, and measured by colorimetry. For the sample after prepolymerization, the content was calculated using the mass excluding the prepolymerized polymer.

(2) Phthalate content:
The sample was accurately weighed, decomposed with sulfuric acid, and the phthalate ester was extracted into heptane. The concentration of the phthalate ester in the heptane solution was determined by comparison with a standard sample using gas chromatography. The content of the phthalate ester in the sample was calculated from the concentration of the phthalate ester in heptane and the mass of the sample. For samples after prepolymerization, the content was calculated using the mass excluding the prepolymerized polymer.

(3) Alkoxysilane Compound Content:
The sample was accurately weighed and decomposed with methanol. The concentration of silicon compounds in the resulting methanol solution was determined by comparing with a standard sample using gas chromatography. The content of silicon compounds in the sample was calculated from the concentration of silicon compounds in methanol and the mass of the sample. For samples after prepolymerization, the content was calculated using the mass excluding the prepolymerized polymer.

(4) MFR:
Using a melt indexer manufactured by Takara Corporation, the evaluation was carried out under conditions of 230° C. and 21.18 N based on JIS-K6921.

(5) 40℃ soluble content (TREF):
The measurement of the 40° C. soluble matter by TREF is as follows.
The sample was dissolved in orthodichlorobenzene at 140° C. to obtain a solution. This was introduced into a temperature rising elution fractionation chromatography (TREF) column at 140° C., and then cooled to 100° C. at a temperature decreasing rate of 8° C./min. The temperature was decreased to 40° C. at a rate of 4° C./min, and then the sample was kept at 40° C. for 10 minutes.
Thereafter, the solvent orthodichlorobenzene was passed through the column at a flow rate of 1 mL/min, and the components dissolved in orthodichlorobenzene at 40° C. in the TREF column were eluted for 10 minutes to determine the components soluble at 40° C.
The TREF device configuration used is as follows.
Column size: 4.3 mmφ x 150 mm stainless steel column Column packing material: 100 μm surface deactivated glass beads Solvent: orthodichlorobenzene Sample concentration: 5 mg/mL
Sample injection volume: 0.1 mL
Solvent flow rate: 1 mL/min Detector: fixed wavelength infrared detector, FOXBORO, MIRAN, 1A
・Measurement wavelength: 3.42μm

(6) Melting point:
A differential scanning calorimeter DSC6200 manufactured by Seiko Instruments Inc. was used. 5 mg of a sheet-shaped sample piece was packed in an aluminum pan, and the sample was heated from room temperature to 200° C. at a heating rate of 100° C./min, held at 200° C. for 5 minutes, cooled to 20° C. at a heating rate of 10° C./min to crystallize, and then heated to 200° C. at a heating rate of 10° C./min to obtain a melting curve. The peak top temperature of the main endothermic peak in the heating stage of the melting curve was taken as the melting point.

Example 1
[Preparation of solid component (A1)]
A 10 L autoclave equipped with a stirrer was thoroughly purged with nitrogen, and 2 L of purified toluene was introduced thereinto.
To this, 200 g of diethoxymagnesium (Mg(OEt) ₂ ) as a magnesium source and 1 L of titanium tetrachloride (TiCl ₄ ) as a titanium source were added at room temperature.
The temperature was raised to 90° C. and 50 ml of di-n-butyl phthalate was introduced as an electron donor.
Thereafter, the temperature was raised to 110° C. and the reaction was carried out for 3 hours.
The reaction product was then thoroughly washed with purified toluene.
Next, purified toluene was introduced into the autoclave to adjust the total liquid volume to 2 L.
Then, 1 L of _TiCl4 was added at room temperature, and the temperature was raised to 110° C. to carry out a reaction for 2 hours.
The reaction product was then thoroughly washed with purified toluene.
Next, purified toluene was again introduced into the autoclave to adjust the total liquid volume to 2 L.
1 L of _TiCl4 was added at room temperature, the temperature was raised to 110° C., and the reaction was carried out for 2 hours.
The reaction product was thoroughly washed with purified toluene, and then purified n-heptane was used to replace the toluene, to obtain a slurry of solid component (A1).

[Prepolymerization of solid component (A1)]
A 20 L capacity autoclave equipped with a stirrer was thoroughly purged with nitrogen, and 200 g of the above slurry of solid component (A1) was introduced into the autoclave as solid component (A1).
Purified n-heptane was introduced into the autoclave, and the concentration of the solid component (A1) was adjusted to 25 g/L.
After the slurry was cooled to 10° C., 20 g of a solution of triethylaluminum (Et ₃ Al) diluted with n-heptane was added as a cocatalyst as Et ₃ Al, and 420 g of propylene was fed over 4 hours.
After the supply of propylene was completed, the reaction was continued for another 30 minutes.
Next, the gas phase was thoroughly replaced with nitrogen, and the reaction product was thoroughly washed with purified n-heptane to obtain a solid component (A1') as a prepolymerized solid component (A1).

[Preparation of solid catalyst component (A)]
Thereafter, purified n-heptane was introduced into the autoclave containing the solid component (A1') to adjust the liquid level to 4 L. To this were added 50 ml of dimethyldivinylsilane as component (A2), 40 ml of t-butylmethyldimethoxysilane (t-Bu(Me)Si(OMe) ₂ ) as component (A3), and 80 g of a diluted n-heptane solution of _Et3Al as component (A4), and the reaction was carried out at 70°C for 2 _hours .
The reaction product was thoroughly washed with purified n-heptane.
A portion of the resulting slurry was sampled and dried.
The resulting slurry was taken out of the autoclave and dried in vacuum to obtain a solid catalyst component (A).
This solid catalyst component (A) contained 2.1 g of polypropylene per 1 g of the solid component. Analysis revealed that the portion of this solid catalyst component (A) excluding polypropylene contained 278 μmol/g of Ti, 28 μmol/g of di-n-butyl phthalate as an electron donor, and 425 μmol/g of t-Bu(Me)Si(OMe) ₂ as component (A3).

[Polymerization of propylene]
A 3.0 liter stainless steel autoclave equipped with a stirrer and a temperature controller was heated and dried under vacuum, cooled to room temperature, and then propylene was substituted.
Thereafter, 550 mg (0.00482 mol) of Et ₃ Al as component (B), 186 mg (0.00194 mol) of 2,5-dimethylfuran as component (C), and 8000 ml of hydrogen were introduced, followed by 1000 g of liquid propylene as a polymerization monomer, and the internal temperature was adjusted to 70°C.
Thereafter, 7 mg of the above solid catalyst component (A) was pressed into the reactor, and propylene was polymerized.
After one hour, 10 ml of ethanol was injected to terminate the polymerization.
The resulting polypropylene was dried and weighed, and the results are shown in Table 1.

Example 2
Propylene polymerization was carried out in the same manner as in Example 1, except that the amount of 2,5-dimethylfuran used as component (C) was 93 mg (0.00097 mol). The results are shown in Table 1.

Example 3
Propylene polymerization was carried out in the same manner as in Example 1, except that the amount of 2,5-dimethylfuran used as component (C) was 301 mg (0.00314 mol). The results are shown in Table 1.

Example 4
Propylene polymerization was carried out in the same manner as in Example 1, except that 130 mg (0.00191 mol) of furan was used instead of 2,5-dimethylfuran as component (C). The results are shown in Table 1.

Example 5
Propylene polymerization was carried out in the same manner as in Example 1, except that 158 mg (0.00192 mol) of 2-methylfuran was used instead of 2,5-dimethylfuran as component (C). The results are shown in Table 1.

(Comparative Example 1)
Propylene polymerization was carried out in the same manner as in Example 1, except that component (C) was not used. The results are shown in Table 1.

(Comparative Example 2)
Propylene polymerization was carried out in the same manner as in Example 1, except that the solid component (A1') prepared in the same manner as in Example 1 was used as the solid catalyst component (A). The results are shown in Table 1.

(Comparative Example 3)
Propylene polymerization was carried out in the same manner as in Example 1, except that 139 mg (0.00191 mol) of tetrahydrofuran was used instead of 2,5-dimethylfuran as component (C). The results are shown in Table 1.

As is clear from Table 1, by comparing the Examples and Comparative Examples, it is possible to obtain polypropylene having a small amount of soluble matter (amorphous component) at 40° C. and a high melting point (stereoregularity) by using the polymerization catalyst containing the solid catalyst component (A) of the present invention.
Specifically, when comparing Examples 1 to 5 with Comparative Examples 1 and 3, it can be seen that by using an unsaturated cyclic ether compound as component (C), the soluble content of the polymer obtained by polymerization can be significantly reduced and the melting point is also improved.
In Comparative Example 2, the components (A2) to (A4) were used without being added to the component (A1), so that the soluble content of the polymer obtained by polymerization was significantly increased, and the melting point was significantly decreased.

According to the present invention, it is possible to produce a propylene-based polymer with a small amount of amorphous components and high stereoregularity, and the resulting polymer has high industrial applicability.

Claims (3)

A method for producing a propylene polymer, comprising the following steps (I) and (II):
Step (I): A step of obtaining a solid catalyst component (A) by adding the following components (A2), (A3) and (A4) to the following component (A1): Component (A1): A solid component containing titanium, magnesium, a halogen and an electron donor as essential components; Component (A2): A silane compound having an alkenyl group; Component (A3): An alkoxysilane compound [however, different from the silane compound having an alkenyl group].
Component (A4): An organoaluminum compound. Step (II): A step of polymerizing a polymerizable monomer by contacting the solid catalyst component (A) with the following components (B) and (C) in the presence of the polymerizable monomer.
(Here, the polymerizable monomer is propylene, or propylene and ethylene, or propylene and an α-olefin having 4 to 22 carbon atoms.)
Component (B): an organoaluminum compound Component (C): an unsaturated cyclic ether compound (wherein component (C) is represented by the following general formula (1) :

In the general formula (1), ^R1 and ^R2 are hydrogen atoms or hydrocarbon groups, and ^R1 and ^R2 may be the same or different. The method for producing a propylene-based polymer according to claim 1, wherein the component (A2) is a vinylsilane compound. The method for producing a propylene-based polymer according to claim 1 or 2, wherein the component (A3) is represented by the following general formula (2):
^R3R4mSi ( ^OR5 _{) n} ...( ² )
(In the general formula (2), ^R3 represents a hydrocarbon group or a heteroatom-containing hydrocarbon group. ^R4 represents hydrogen, a halogen, a hydrocarbon group or a heteroatom-containing hydrocarbon group. ^R5 represents a hydrocarbon group. m and n each represent an integer such that 0≦m≦2, 1≦n≦3, or m+n=3.)