JP7021915B2 - A method for producing a solid catalyst component for olefin polymerization, a method for producing a catalyst for olefin polymerization, and a method for producing an olefin polymer. - Google Patents

Description

The present invention relates to a method for producing a solid catalyst component for olefin polymerization, a method for producing a solid catalyst component for olefin polymerization, a method for producing a catalyst for olefin polymerization, and a method for producing an olefin polymer.

Conventionally, as a catalyst for olefin polymerization, a solid catalyst composed of a transition metal catalyst component such as titanium and a typical metal catalyst component such as aluminum is widely known.

In the polymerization of olefins such as propylene, a solid catalyst component containing a magnesium atom, a titanium atom, a halogen atom and an electron donating compound as essential components is known. Further, many methods for polymerizing or copolymerizing olefins in the presence of a catalyst for polymerizing olefins composed of the solid catalyst component, an organoaluminum compound and an organosilicon compound have been proposed (for example, Patent Document 1 and Patent Documents). 2).

Japanese Unexamined Patent Publication No. 11-10634 International Publication No. 2013/027560

In Patent Document 1 (Japanese Unexamined Patent Publication No. 11-106434), it is described that a propylene-based random copolymer is produced by copolymerizing propylene with an α-olefin other than propylene, for example, ethylene, using a solid catalyst component. Attempts have been made, and it is said that the higher the proportion of ethylene in the copolymer, the lower the melting point of the propylene-based random copolymer obtained as described above.

However, when a propylene-based random copolymer is produced by the method described in Patent Document 1, the higher the ethylene content in the copolymer, the lower the melting point of the obtained copolymer, but the wider the composition distribution. In addition, so-called polyethylene moieties (portions in which polyethylene is continuously polymerized) are likely to be formed in the polymer molecular chain, making it difficult to obtain a propylene-based random copolymer having a low dispersibility of ethylene and a uniform composition, as described above. It has been found that such a copolymer composition having low ethylene dispersibility tends to have a large amount of sticky component at the time of molding and a decrease in blocking resistance when used for film production.

On the other hand, as in Patent Document 2 (International Publication No. 2013/027560), an internal electron donating compound selected from a magnesium compound, a tetravalent titanium halogen compound and phthalic acid diesters is obtained by contacting each other. We propose a solid catalyst component for olefin polymerization obtained by contacting the solid component with an internal electron donating compound selected from malonic acid diesters, an organic aluminum compound, and an olefin polymerization catalyst composed of an organic silicon compound. , A method for polymerizing olefins using the polymerization catalyst has been proposed, and the olefin polymer obtained from such a solid catalyst component has a high fluidity (MFR) of the molten polymer, and is particularly large-sized by injection molding or the like. It is said to be useful when manufacturing products.

However, as a result of studies by the present inventors, the solid catalyst component described in Patent Document 2 is obtained by polymerizing the obtained homopolypropylene under conditions such that the melting point of the obtained homopolypropylene is 157 to 160 ° C. It was found that not only the NMR-mm mm showing regularity was reduced to less than 91%, but also there was still room for improvement in terms of melt tension, surface stickiness, and blocking resistance when used in film production.

Under such circumstances, a propylene homopolymer (homopolypolymer) having a low melting point of less than 160 ° C., a high degree of steric regularity, and an excellent melt tension can be obtained without coexistence of α-olefins other than propylene such as ethylene. There has been a demand for a solid catalyst component for olefin polymerization, a method for producing a solid catalyst component for olefin polymerization, a method for producing a catalyst for olefin polymerization, and a method for producing an olefin polymer, which can be produced under high polymerization activity.

In such a situation, as a result of diligent studies to solve the above problems, the present inventors have contacted and reacted the magnesium compound, the titanium halogen compound, and the first internal electron donating compound. In the first step of washing, the present of a hydrocarbon solvent is used to add 0.001 to 0.1 mol of a second internal electron donating compound per mol of magnesium atom contained in the magnesium compound to the obtained product. The second step of removing the hydrocarbon solvent after contacting and reacting with the bottom, the third step of washing with an organic solvent containing a titanium halogen compound of more than 5% by volume and 50% by volume or less, and titanium. It has been found that the above technical problems can be solved by a solid catalyst component for olefin polymerization, which is sequentially subjected to a fourth step of washing with an organic solvent containing no halogen compound at least once, and the present invention has been completed. ..

That is , the present invention
(1 ) The first step of contacting a magnesium compound, a titanium halogen compound, and a first internal electron donating compound, reacting them, and then washing them.
After contacting and reacting the obtained product with a second internal electron donating compound of 0.001 to 0.1 mol per mol of magnesium atom contained in the magnesium compound in the presence of a hydrocarbon solvent. , A second step of removing the hydrocarbon solvent,
The third step of washing once or more with an organic solvent containing a titanium halogen compound of more than 5% by volume and 50% by volume or less and the fourth step of washing once or more with an organic solvent not containing a titanium halogen compound are sequentially performed . ,
The first internal electron donating compound is a phthalic acid diester.
The second internal electron donating compound is an alkyl-substituted malonic acid diester.
A method for producing a solid catalyst component for olefin polymerization, which is characterized by the above.
(2 ) (I) The solid catalyst component for olefin polymerization obtained by the production method described in (1 ) above, and (II) the following general formula (1);
R ¹ _p AlQ _3-p (1)
(In the formula, R ¹ is an alkyl group having 1 to 6 carbon atoms, Q is a hydrogen atom or a halogen atom, p is a real number of 0 <p ≦ 3, and when there are a plurality of R ¹ , each R ¹ is It may be the same or different, and when a plurality of Qs are present, each Q may be the same or different). Method of manufacturing catalyst for
( 3 ) Further, (III) the method for producing a catalyst for olefin polymerization according to ( 2 ) above, in which an external electron donating compound is brought into contact with the catalyst.
( 4 ) The (III) external electron donating compound is the following general formula (2);
R ² _q Si (OR ³ ) _4-q (2)
(In the formula, R ² is an alkyl group having 1 to 12 carbon atoms, a cycloalkyl group having 3 to 12 carbon atoms, a phenyl group, a vinyl group, an allyl group, an aralkyl group, an alkylamino group having 1 to 12 carbon atoms or a carbon. It is a dialkylamino group having the number 1 to 12, and when a plurality of R ^2s are present, each R ² may be the same or different. R ³ is an alkyl group having 1 to 4 carbon atoms and 3 carbon atoms. It is a cycloalkyl group, a phenyl group, a vinyl group, an allyl group or an aralkyl group of up to 6, and when a plurality of R ^3s are present, each R ³ may be the same or different. Q is 0 ≦ q ≦. It is an integer of 3.)
The method for producing a catalyst for polymerizing olefins according to ( 3 ) above, which is one or more organosilicon compounds selected from the above.
( 5 ) Production of an olefin polymer, which comprises polymerizing olefins in the presence of a catalyst for olefin polymerization obtained by the production method according to any one of ( 2 ) to ( 4 ) above. Method,
( 6 ) The method for producing an olefin polymer according to ( 5 ) above, wherein the olefin is propylene, and ( 7 ) the obtained olefin polymer has a melt flow rate of 1.0 kg / 10 minutes or more and a melting point. The method for producing an olefin polymer according to ( 5 ) or ( 6 ) above, which is in the range of 157 to 160 ° C. and has an isotactic pentad fraction of 91.0% or more.
Is to provide.

According to the present invention, a propylene homopolymer (homopolypolymer) having a low melting point of less than 160 ° C., a high degree of steric regularity, and an excellent melt tension can be obtained without coexistence of α-olefins other than propylene such as ethylene. It is possible to provide a solid catalyst component for olefin polymerization, a method for producing a solid catalyst component for olefin polymerization, a method for producing a catalyst for olefin polymerization, and a method for producing an olefin polymer, which can be produced under high polymerization activity.

First, the solid catalyst component for olefin polymerization according to the present invention was obtained in the first step of contacting and reacting a magnesium compound, a titanium halogen compound, and a first internal electron donating compound, and then washing. The product is contacted with and reacted with a second internal electron donating compound of 0.001 to 0.1 mol per mol of magnesium atom contained in the magnesium compound in the presence of a hydrocarbon solvent, and then the carbonized product. The second step of removing the hydrogen solvent, the third step of washing with an organic solvent containing a titanium halogen compound of more than 5% by volume and 50% by volume or less, and one or more times with an organic solvent containing no titanium halogen compound. It is characterized in that the fourth step of cleaning is sequentially performed.
Since the solid catalyst component for olefin polymerization according to the present invention is represented by the method for producing the solid catalyst component, details of the production method and the like will be described below.

In the solid catalyst component for olefin polymerization according to the present invention, the magnesium compound may be selected from magnesium halide, dialkylmagnesium, alkylmagnesium halide, dialkoxymagnesium, diallyloxymagnesium, alkoxymagnesium halide, magnesium fatty acid and the like. There are more than one.
Among these magnesium compounds, dialkoxymagnesium is preferable, and specific examples thereof include dimethoxymagnesium, diethoxymagnesium, dipropoxymagnesium, dibutoxymagnesium, ethoxymethoxymagnesium, ethoxypropoxymagnesium, butoxyethoxymagnesium, and the like. Magnesium is particularly preferred.
Further, the dialkoxymagnesium may be obtained by reacting metallic magnesium with an alcohol in the presence of a halogen, a halogen-containing metal compound or the like.
Further, the magnesium compound may be used alone or in combination of two or more.

Further, as the dialkenyl magnesium constituting the solid catalyst component for olefin polymerization according to the present invention, those in the form of granules or powder are preferable, and those having an amorphous or spherical particle shape are suitable.
For example, when the magnesium compound is spherical dialkoxymagnesium, a polymer powder having a better particle shape (more spherical) and a narrow particle size distribution can be easily obtained, and the produced polymer powder during the polymerization operation can be easily obtained. The handling operability is improved, and the blockage of the pipe caused by the fine powder contained in the produced polymer powder can be easily suppressed.

The spherical dialkoxymagnesium does not necessarily have to be a true sphere, and includes an elliptical shape or a potato-shaped one. Specifically, the shape of the particles has a circularity obtained from the area S and the perimeter L of the particles. A value of 3 or less is suitable, a value of 1 to 2 is more suitable, and a value of 1 to 1.5 is more suitable.
In this application document, the circularity of dialkoxymagnesium is defined as the area S of each particle by photographing 500 or more dialkoxymagnesium particles with a scanning electron microscope and processing the photographed particles with image analysis processing software. And the peripheral length L is obtained, and the circularity of each dialkoxymagnesium particle is calculated by the following formula. Circularity of each dialkoxymagnesium particle = L ² ÷ (4π × S)
It means the arithmetic mean value when calculated by, and the closer the shape of the particle is to a perfect circle, the closer the circularity is to 1.

The magnesium compound preferably has an average particle size of 1 to 200 μm, and more preferably 5 to 150 μm.
When the magnesium compound is spherical dialkoxymagnesium, the average particle size thereof is preferably 1 to 100 μm, more preferably 5 to 50 μm, still more preferably 10 to 40 μm.

In this application document, the average particle size of the magnesium compound is the average particle size D ₅₀ (50% of the integrated particle size in the volume integrated particle size distribution) when measured using a laser light scattering diffraction method particle size measuring machine. ) Means.

The magnesium compound preferably has a narrow particle size distribution with few fine powders and coarse powders.
Specifically, particles having a size of 5 μm or less are preferably 20% or less, and more preferably 10% or less.
On the other hand, particles having a size of 100 μm or more are preferably 10% or less, and more preferably 5% or less.
Further, the particle size distribution is ln (D ₉₀ / D ₁₀ ) (where D ₉₀ is the integrated particle size of 90% in the volume integrated particle size distribution, and D ₁₀ is the integrated particle size of 10% in the volume integrated particle size distribution. It is preferably 3 or less, and more preferably 2 or less.

Examples of the method for producing the spherical dialkoxymagnesium include JP-A-58-41832, JP-A-62-51633, JP-A-3-74341, JP-A-4-368391, and JP-A-8-. It is exemplified in Japanese Patent Publication No. 73388.

The magnesium compound is preferably in the form of a solution or a suspension at the time of reaction, and the reaction can be suitably carried out by being in the form of a solution or a suspension.

When the magnesium compound is a solid, it can be made into a solution magnesium compound by dissolving it in a solvent having a solubilizing ability of the magnesium compound, or it is suspended in a solvent having no solubilizing ability of the magnesium compound. By making it turbid, it can be made into a magnesium compound suspension.
When the magnesium compound is in a liquid state, it may be used as it is as a solution magnesium compound, or it may be further dissolved in a solvent having a solubilizing ability of the magnesium compound and used as a solution magnesium compound. ..

The titanium halogen compound in the solid catalyst component for olefin polymerization according to the present invention is not particularly limited, but is described in the following general formula (3).
Ti (OR ⁴ ) _r X _4-r (3)
(In the formula, R ⁴ represents an alkyl group having 1 to 4 carbon atoms, X represents a halogen atom such as a chlorine atom, a bromine atom, and an iodine atom, and r is 0 or an integer of 1 to 3). It is preferably one or more of the compounds selected from the group of titanium halides or alkoxytitanium halides to be used.

Examples of the titanium halide include titanium tetrahalides such as titanium tetrachloride, titanium tetrabromide, and titanium tetraiodide.
Examples of the alkoxytitanium halide include methoxytitanium trichloride, ethoxytitanium trichloride, propoxytitanium trichloride, n-butoxytitanium trichloride, dimethoxytitanium dichloride, diethoxytitanium dichloride, dipropoxytitanium dichloride, and di-n-butoxytitanium. One or more selected from dichloride, trimethoxy titanium chloride, triethoxy titanium chloride, tripropoxy titanium chloride, tri-n-butoxy titanium chloride and the like can be mentioned.
As the titanium halogen compound, titanium tetrahalide is preferable, and titanium tetrachloride is more preferable.
These titanium halogen compounds can be used alone or in combination of two or more.

Examples of the first internal electron donating compound include one or more selected from phthalic acid diester, malonic acid diester, maleic acid diester, succinic acid diester, alkoxyalkyl ester, cyclohexene dicarboxylic acid diester and cyclohexanedicarboxylic acid diester.

As the first internal electron donating compound, one or more selected from phthalic acid diester, malonic acid diester, alkyl-substituted malonic acid diester, maleic acid diester, succinic acid diester, cyclohexene dicarboxylic acid diester and cyclohexanedicarboxylic acid diester is preferable. , Phtalic acid diester, malonic acid diester, alkyl substituted malonic acid diester, succinic acid diester, cyclohexene dicarboxylic acid diester and cyclohexanedicarboxylic acid diester, more preferably one or more, phthalic acid diester, cyclohexene dicarboxylic acid diester and cyclohexanedicarboxylic acid diester. More preferably, one or more selected from, more preferably one or more selected from phthalic acid diester, 1-cyclohexene-1,2-dicarboxylic acid diester, 4-cyclohexene-1,2-dicarboxylic acid diester and cyclohexanedicarboxylic acid diester. More preferably, one or more selected from di-n-butyl phthalate and diisobutyl phthalate.

The solid catalyst component for olefin polymerization according to the present invention is formed by contacting and reacting a magnesium compound, a titanium halogen compound, and a first internal electron donating compound in the first step, and then washing the compound. be.

The contact between the magnesium compound, the titanium halogen compound, and the first internal electron donating compound in the first step is preferably carried out under an inert gas atmosphere and in a state where water and the like are removed, with stirring. ..

The contact temperature of each component may be in a relatively low temperature range near room temperature in the case of simply contacting and stirring and mixing, or in the case of dispersion or suspension for denaturation treatment, but the reaction is carried out after contact. When a product is obtained, the temperature is preferably 40 to 130 ° C. because the reaction rate and reaction control are easy. The stirring time is preferably 1 minute or longer, more preferably 10 minutes or longer, and even more preferably 30 minutes or longer.

The cleaning treatment in the first step is preferably performed using a hydrocarbon compound that is liquid at room temperature as a cleaning agent, and the hydrocarbon compound that does not contain a halogen atom and is liquid at room temperature is preferable. Aromatic hydrocarbon compounds or saturated hydrocarbon compounds that are liquid at room temperature are preferred.
Specifically, linear or branched aliphatic hydrocarbon compounds having a boiling point of 50 to 150 ° C. such as hexane, heptane, decane, and methylheptane, and alicyclic hydrocarbons having a boiling point of 50 to 150 ° C. such as cyclohexane and ethylcyclohexane. One or more selected from compounds, toluene, xylene, ethylbenzene and other aromatic hydrocarbon compounds having a boiling point of 50 to 150 ° C. can be mentioned. Among the above, linear aliphatic hydrocarbon compounds having a boiling point of 50 to 150 ° C. can be mentioned. And one or more selected from aromatic hydrocarbon compounds having a boiling point of 50 to 150 ° C. and the like are preferable, aromatic hydrocarbon compounds having a boiling point of 50 to 150 ° C. are more preferable, and one or more selected from toluene, heptane and ethylbenzene are more preferable.

The temperature during the cleaning treatment in the first step is preferably 0 to 110 ° C, more preferably 30 to 100 ° C, still more preferably 30 to 90 ° C.
The amount of the washing liquid used in the first step is preferably 1 to 500 mL, more preferably 3 to 200 mL, and even more preferably 5 to 100 mL per 1 g of the reaction product.
The number of washings in the first step may be once or a plurality of times, but is preferably 1 to 20 times, more preferably 1 to 15 times, still more preferably 1 to 10 times. Even when the number of washings is a plurality of times, it is preferable to use the above-mentioned amount of the washing liquid for each washing.

In a particularly preferred embodiment of the first step, spherical dialkoxymagnesium is suspended in a hydrocarbon compound having a boiling point of 50 to 150 ° C., and then one or two of the first electron donating compounds are suspended in this suspension. After contacting the above, the suspension is brought into contact with a tetravalent titanium halogen compound to carry out a reaction treatment, and the reaction-treated product is washed with a cleaning liquid which is a liquid hydrocarbon compound at room temperature. be able to.

In the first step, before or after contacting the first electron donating compound, preferably at a temperature of −20 to 70 ° C., more preferably −10 to 60 ° C., still more preferably −10 to 30 ° C. The aging reaction is preferably carried out for 1 minute to 6 hours, more preferably 5 minutes to 4 hours, still more preferably 10 minutes to 3 hours, and then preferably 30 to 130 ° C., more preferably 40 to 120 ° C., still more preferably. Is preferably subjected to the reaction treatment at a temperature of 50 to 115 ° C. for preferably 0.5 to 6 hours, more preferably 0.5 to 5 hours, still more preferably 1 to 4 hours.
After the above reaction is completed, the suspension after the washing treatment may be allowed to stand as appropriate to remove the supernatant liquid to form a wet state (slurry), or further to a dry state by hot air drying or the like, or after the washing treatment. The residual supernatant liquid may not be removed and may be subjected to the second step in the state of a suspension. When the suspension is subjected to the second step as it is, the drying treatment can be omitted and the addition of the inert organic solvent can be omitted in the second step.

The solid catalyst component for olefin polymerization according to the present invention has a second internal content of 0.001 to 0.1 mol per mol of magnesium atom contained in the magnesium compound with respect to the product obtained in the first step. The electron donating compound is contacted and reacted in the presence of a hydrocarbon solvent, and then a second step of removing the hydrocarbon solvent is performed.

Examples of the second internal electron donating compound include the same compounds as those mentioned above as the first internal electron donating compound, which include a phthalic acid diester, a malonic acid diester, an alkyl-substituted malonic acid diester, and a maleic acid. One or more selected from a diester, a succinic acid diester, an alkoxyalkyl ester, a cycloalkene dicarboxylic acid diester, a cycloalkanedicarboxylic acid diester and the like can be mentioned. One or more selected from alkyl esters, cycloalkendicarboxylic acid diesters, cycloalkandicarboxylic acid diesters and the like is preferable.
One or more selected from phthalic acid diester, malonic acid diester, alkyl-substituted malonic acid diester, maleic acid diester, succinic acid diester, cyclohexene dicarboxylic acid diester and the like is more preferable, and phthalic acid diester, malonic acid diester, alkyl-substituted malonic acid diester, etc. One or more selected from maleic acid diesters, succinic acid diesters and the like are more preferable, and phthalic acid diesters other than phthalic acid di-n-butyl and phthalic acid isobutyl, malonic acid diesters, alkyl-substituted malonic acid diesters and maleic acid diesters are selected. One or more of them are more preferable, and one or more selected from phthalic acid diesters other than di-n-butyl phthalate and isobutyl phthalate, malonic acid diester and the like are even more preferable.

The first internal electron donating compound and the second internal electron donating compound may be the same as each other or may be different from each other.

As a combination of the first internal electron donating compound and the second internal electron donating compound,
(1) The first internal electron donating compound is selected from phthalic acid diester, and the second internal electron donating compound is selected from phthalic acid diester, malonic acid diester, alkyl-substituted malonic acid diester, alkoxyalkyl ester and maleic acid diester. Any combination,
(2) The first internal electron donating compound is a cyclohexene dicarboxylic acid diester, and the second internal electron donating compound is a combination selected from a phthalic acid diester, a malonic acid diester and an alkyl-substituted malonic acid diester, or
(3) A combination selected from cyclohexanedicarboxylic acid diester as the first internal electron donating compound and phthalic acid diester, malonic acid diester and alkyl-substituted malonic acid diester as the second internal electron donating compound.
It is preferable to select from
(4) The combination of the first internal electron donating compound is a phthalic acid diester and the second internal electron donating compound is an alkyl-substituted malonic acid diester.
(5) The first internal electron donating compound is a cyclohexene dicarboxylic acid diester, the second internal electron donating compound is a combination of an alkyl-substituted malonic acid diester, and the first internal electron donating compound is a cyclohexanedicarboxylic acid diester. It is more preferable that the second internal electron donating compound is a combination of an alkyl-substituted malonic acid diester.

The contact amount of the second internal electron donating compound with the product obtained in the first step is 0.001 to 0.1 mol per mol of the magnesium atom contained in the product, and 0. It is preferably 005 to 0.05 mol, more preferably 0.008 to 0.03 mol.
By setting the contact amount of the second internal electron donating compound within the above range, the formation of non-stereospecific active points in the obtained solid catalyst component is suppressed, and the reaction occurs in the obtained solid catalyst component. Since by-products and excess titanium components are efficiently removed, the stereoregularity of the obtained low melting point polypropylene can be maintained at a high level when such a solid catalyst component is applied to the polymerization of propylene. ..

In the second step, the product obtained in the first step is brought into contact with the second internal electron donating compound in the presence of a hydrocarbon solvent and reacted.
The contact and reaction between the product obtained in the first step and the second internal electron donating compound are preferably carried out under stirring.
In the second step, by contacting the second internal electron donating compound in the presence of the above hydrocarbon solvent, the contact property of the second internal electron donating compound with respect to the product obtained in the first step. Can be improved.

As the hydrocarbon solvent used in the second step, one or more selected from the hydrocarbon compounds used as a cleaning agent in the cleaning treatment of the first step can be exemplified.
The concentration of the titanium halogen compound in the hydrocarbon solvent to be contacted and reacted in the second step is particularly high as long as the adsorption of the second internal electron donating compound to the product obtained in the first step is not inhibited. Not limited, but preferably as low as possible. In order to suppress the formation of the complex compound due to the interaction between the second internal electron donating compound and the titanium halogen compound, the concentration of the titanium halogen compound in the hydrocarbon solvent is preferably 10% by volume or less, preferably 5% by volume or less. It is more preferably 3% by volume or less, and even more preferably 1% by volume or less.
By setting the concentration of the titanium halogen compound contained in the hydrocarbon solvent in the second step within the above range, the second internal electron donating compound can be efficiently adsorbed to the product obtained in the first step. This is done and the formation of non-stereospecific active points is suppressed.
In order to control the concentration of the titanium halogen compound contained in the hydrocarbon solvent within the above range, it is preferable not to newly add the titanium halogen compound to the reaction system in the second step.

In the second step, the temperature at which the second internal electron donating compound is brought into contact with and reacted is preferably 40 to 130 ° C, more preferably 60 to 120 ° C, still more preferably 70 to 120 ° C.
If the contact and reaction temperature is less than 40 ° C, the reaction does not proceed sufficiently, the performance of the resulting solid catalyst component becomes insufficient, and if the contact and reaction temperature exceeds 130 ° C, the solvent used evaporates. It becomes difficult to control the reaction.
The time for contacting and reacting the second internal electron donating compound is preferably 1 minute or longer, more preferably 3 minutes to 60 minutes, and even more preferably 5 minutes to 30 minutes.

In the second step, the hydrocarbon solvent is removed after the second internal electron donating compound is contacted and reacted.
In the second step, by contacting and reacting the second internal electron donating compound in the presence of the hydrocarbon solvent and then removing the hydrocarbon solvent, impurities and the like remaining in the reaction system can be easily removed. Can be removed.

The solid catalyst component for olefin polymerization according to the present invention is subjected to the second step, and then once with an organic solvent containing a titanium halogen compound of more than 5% by volume and 50% by volume or less with respect to the obtained product. The third step of cleaning is performed as described above.

Specific examples of the titanium halogen compound include those similar to those exemplified in the first step.

The organic solvent preferably contains a hydrocarbon compound that is liquid at room temperature that dissolves the titanium halogen compound, and the hydrocarbon compound preferably does not contain a halogen atom and is liquid at room temperature, and is aromatic at room temperature. Hydrocarbon compounds or saturated hydrocarbon compounds are preferred.
Specifically, linear or branched aliphatic hydrocarbon compounds having a boiling point of 50 to 150 ° C. such as hexane, heptane, decane, and methylheptane, and alicyclic hydrocarbons having a boiling point of 50 to 150 ° C. such as cyclohexane and ethylcyclohexane. One or more selected from compounds, toluene, xylene, ethylbenzene and other aromatic hydrocarbon compounds having a boiling point of 50 to 150 ° C. can be mentioned. Among the above, linear aliphatic hydrocarbon compounds having a boiling point of 50 to 150 ° C. can be mentioned. And one or more selected from aromatic hydrocarbon compounds having a boiling point of 50 to 150 ° C. and the like are preferable, aromatic hydrocarbon compounds having a boiling point of 50 to 150 ° C. are more preferable, and one or more selected from toluene, heptane and ethylbenzene are more preferable.

The content of the titanium halogen compound in the organic solvent used in the third step is more than 5% by volume and 50% by volume or less, preferably 5 to 49% by volume, more preferably 5 to 45% by volume, and 10 to 10 to 45% by volume is more preferable.
The titanium halogen compound in the organic solvent used in the third step is the titanium halogen compound in the organic solvent utilizing the unreacted titanium halogen compound remaining in the system after the hydrocarbon solvent is removed in the second step. The amount may be controlled, but in order to more easily control the amount of the titanium halogen compound in the organic solvent, after removing the hydrocarbon solvent in the second step, titanium such as a tetravalent titanium halogen compound is newly added. It is preferable to add the halogen compound directly to the organic solvent or system.

By controlling the content of the titanium halogen compound in the organic solvent within the above range, the activity of the catalyst can be easily controlled.

The temperature during the cleaning treatment in the third step is preferably 80 to 130 ° C, more preferably 90 to 120 ° C, and even more preferably 100 to 110 ° C.
In the third step, the number of cleaning treatments with the organic solvent containing the titanium halogen compound is 1 or more, preferably 2 or more, more preferably 2 to 6 times, still more preferably 2 to 5 times.
By setting the number of cleaning treatments with an organic solvent containing a titanium halogen compound within the above range, reaction by-products and excess titanium components can be easily removed.
In the method for producing a solid catalyst component for olefin polymerization of the present invention, the reaction product obtained in the second step may be pretreated and then subjected to the third step. It is preferable to continuously perform the third step without performing the third step.
When the reaction product obtained in the second step is pretreated, for example, the product obtained by removing the organic solvent in the second step is newly subjected to a tetravalent titanium halide as a pretreatment. Examples thereof include an embodiment in which a titanium halogen compound such as a compound is added to the cleaning agent or directly into the system and then cleaned with the cleaning agent. The cleaning in this pretreatment can be performed by the same method as the cleaning in the first step.

The solid catalyst component for olefin polymerization according to the present invention is obtained by subjecting a third step and then a fourth step of washing with an organic solvent containing no titanium halogen compound at least once.

The organic solvent used in the fourth step is preferably one composed of a hydrocarbon compound that can constitute the organic solvent used in the third step, and specific examples of the hydrocarbon compound are as described above.
In particular, as the above-mentioned hydrocarbon compound, an alicyclic hydrocarbon compound having a boiling point of 50 to 150 ° C. and a boiling point of 50 to 150 ° C. is preferable, and a linear aliphatic hydrocarbon compound having a boiling point of 50 to 150 ° C. is more preferable, and hexane is used. And heptan are more preferred.
As a method of washing once or more with an organic solvent that does not contain a titanium halogen compound, the supernatant liquid after the washing treatment in the third step is removed to form a wet state (slurry form), and then a titanium halogen compound is newly contained. A method of performing a cleaning treatment by adding a non-organic solvent, removing the supernatant liquid after the cleaning treatment in the third step, further drying, and then newly adding an organic solvent containing no titanium halogen compound for cleaning. Among these, a method for performing the treatment can be mentioned. Among these, an organic solvent containing no titanium halogen compound is newly obtained after removing the supernatant liquid after the cleaning treatment in the third step to form a wet state (slurry form). Is preferable to perform the cleaning treatment.

The temperature during the cleaning treatment in the fourth step is preferably 20 to 80 ° C, more preferably 30 to 70 ° C, and even more preferably 40 to 60 ° C.
In the fourth step, the number of cleaning treatments with an organic solvent containing no titanium halogen compound is 1 or more, preferably 2 or more, more preferably 2 to 10 times, still more preferably 4 to 6 times.

In the reaction system, the cleaning treatment with the organic solvent containing the titanium halogen compound is performed once or more in the third step, and then the cleaning treatment with the organic solvent containing the titanium halogen compound is performed once or more in the fourth step. It is possible to efficiently remove the unreacted substance, the reaction by-product, and the titanium component having a weak adsorbing power remaining in the solid catalyst component.

After performing the fourth step, the solid catalyst component can be isolated by appropriately performing a solid-liquid separation treatment as necessary.

The solid catalyst component for olefin polymerization according to the present invention preferably has a magnesium atom content of 10 to 70% by mass, more preferably 10 to 50% by mass, and 15 to 40% by mass. Those having an amount of 15 to 25% by mass are more preferable, and those having an amount of 15 to 25% by mass are further preferable.
The solid catalyst component for olefin polymerization according to the present invention preferably has a titanium atom content of 0.5 to 8.0% by mass, preferably 1.0 to 6.0% by mass. More preferably, it is more preferably 4.0 to 4.5% by mass.
The solid catalyst component for olefin polymerization according to the present invention preferably has a halogen atom content of 20 to 85% by mass, more preferably 30 to 80% by mass, and 40 to 75% by mass. Those having an amount of 45 to 70% by mass are more preferable, and those having an amount of 45 to 70% by mass are further preferable.
The solid catalyst component for olefin polymerization according to the present invention preferably has a content of the first internal electron donating compound of 1.0 to 15.0% by mass, preferably 3.0 to 13.0% by mass. Is more preferable, and 5.0 to 11.0% by mass is further preferable.
The solid catalyst component for olefin polymerization according to the present invention preferably has a content of the second internal electron donating compound of 0.1 to 5.0% by mass, preferably 0.3 to 4.0% by mass. Is more preferable, and 0.5 to 3.0% by mass is further preferable.
The solid catalyst component for olefin polymerization according to the present invention preferably has a total content ratio of the first internal electron donating compound and the second internal electron donating compound of 1.1 to 20.0% by mass. It is more preferably 3.3 to 17.0% by mass, and even more preferably 5.5 to 14.0% by mass.

The solid catalyst component for olefin polymerization according to the present invention has a titanium atom content of 4 to 4.5% by mass and a magnesium atom content of 15 to 25% by mass in order to exhibit its overall performance in a well-balanced manner. , The content of halogen atom is 45 to 75% by mass, the content of the first internal electron donating compound is 5.0 to 11.0% by mass, and the content of the second internal electron donating compound is 0.5. It is desirable that the content is ~ 3.0% by mass.

According to the present invention, a propylene homopolymer (homopolypropylene) having a low melting point at less than 160 ° C., maintaining a high degree of stereoregularity, and having excellent melt tension even without the coexistence of α-olefins other than propylene such as ethylene can be obtained. It is possible to provide a solid catalyst component for olefin polymerization that can be produced under high polymerization activity.

Next, a method for producing a solid catalyst component for olefin polymerization according to the present invention will be described.
The method for producing a solid catalyst component for olefin polymerization according to the present invention is the first step of contacting a magnesium compound, a titanium halogen compound, and a first internal electron donating compound, reacting them, and then washing them. After contacting and reacting the obtained product with a second internal electron donating compound of 0.001 to 0.1 mol per mol of magnesium atom contained in the magnesium compound in the presence of a hydrocarbon solvent. The second step of removing the hydrocarbon solvent, the third step of washing with an organic solvent containing a titanium halogen compound of more than 5% by volume and 50% by volume or less, and the third step of washing with an organic solvent containing no titanium halogen compound. It is characterized in that a fourth step of washing once or more is sequentially performed.

The details of the method for producing the solid catalyst component for olefin polymerization according to the present invention are the same as the description related to the production method described in the description of the solid catalyst component for olefin polymerization of the present invention.

According to the present invention, a propylene homopolymer (homopolypropylene) having a low melting point of less than 160 ° C., maintaining a high degree of stereoregularity, and having excellent melt tension without coexistence of α-olefins other than propylene such as ethylene can be obtained. It is possible to provide a method for easily producing a solid catalyst component for olefin polymerization that can be produced under high polymerization activity.

Next, the catalyst for polymerizing olefins according to the present invention will be described.
The catalyst for olefin polymerization according to the present invention is (I) a solid catalyst component for olefin polymerization according to the present invention, and (II) the following general formula (1);
R ¹ _p AlQ _3-p (1)
(In the formula, R ¹ is an alkyl group having 1 to 6 carbon atoms, Q is a hydrogen atom or a halogen atom, p is a real number of 0 <p ≦ 3, and when there are a plurality of R ¹ , each R ¹ is It may be the same or different, and when there are a plurality of Qs, each Q may be the same or different). be.

In the organic aluminum compound represented by the general formula (II), R ¹ is an alkyl group having 1 to 6 carbon atoms, and specifically, a methyl group, an ethyl group, an n-propyl group, an isopropyl group and an n-butyl group. , Isobutyl group and the like.

In the organic aluminum compound represented by the above general formula (II), Q represents a hydrogen atom or a halogen atom, and when Q is a halogen atom, a fluorine atom, a chlorine atom, a bromine atom and an iodine atom can be mentioned.

In the organoaluminum compound represented by the above general formula (II), when a plurality of R ^1s are present, each R ¹ may be the same or different, and when a plurality of Qs are present, each Q may be the same. It may be different.

Specific examples of the organic aluminum compound represented by the general formula (II) include one or more selected from triethylaluminum, diethylaluminum chloride, triisobutylaluminum, diethylaluminum bromide, and diethylaluminum hydride, and triethylaluminum. , Triisobutylaluminum is suitable.

The catalyst for olefin polymerization according to the present invention is further (III) external, together with (I) the solid catalyst component for olefin polymerization according to the present invention, (II) the organoaluminum compound represented by the general formula (1), and (III) external. It may be formed by contacting an electron donating compound.

Examples of such external electron donating compounds include organic compounds containing oxygen atoms or nitrogen atoms, and specific examples thereof include alcohols, phenols, ethers, esters, ketones, acid halides, and the like. Examples thereof include aldehydes, amines, amides, nitriles, isocyanates, organic silicon compounds, and among them, organic silicon compounds having a Si—OC bond.

Among the above external electron donating compounds, esters such as ethyl benzoate, ethyl p-methoxybenzoate, ethyl p-ethoxybenzoate, methyl p-toluic acid, ethyl p-toluic acid, methyl anisate, ethyl anisate and the like. , 1,3-Diethers, organic silicon compounds containing Si—OC bonds are preferred, and organic silicon compounds having Si—OC bonds are particularly preferred.

The external electron donating compound includes the following general formula (2).
R ² _q Si (OR ³ ) _4-q (2)
(In the formula, R ² is an alkyl group having 1 to 12 carbon atoms, a cycloalkyl group having 3 to 12 carbon atoms, a phenyl group, a vinyl group, an allyl group, an aralkyl group, an alkylamino group having 1 to 12 carbon atoms or a carbon. It is a dialkylamino group having the number 1 to 12, and when a plurality of R ^2s are present, each R ² may be the same or different. R ³ is an alkyl group having 1 to 4 carbon atoms and 3 carbon atoms. It is a cycloalkyl group, a phenyl group, a vinyl group, an allyl group or an aralkyl group of up to 6, and when a plurality of R ^3s are present, each R ³ may be the same or different. Q is 0 ≦ q ≦. It is an integer of 3.)
It is preferable that it is one or more organosilicon compounds selected from the above.

Examples of the organic silicon compound include phenylalkoxysilane, alkylalkoxysilane, phenyl (alkyl) alkoxysilane, vinylsilane, allylsilane, cycloalkylalkoxysilane, cycloalkyl (alkyl) alkoxysilane, (alkylamino) alkoxysilane, and alkyl (alkylamino). ) Alkoxysilane, Alkyl (dialkylamino) alkoxysilane, Cycloalkyl (alkylamino) alkoxysilane, (Polycyclic amino) alkoxysilane, (alkylamino) alkylsilane, (dialkylamino) alkylsilane, Cycloalkyl (alkylamino) alkyl Examples thereof include silane, (polycyclic amino) alkylsilane, and among them, di-n-propyldimethoxysilane, diisopropyldimethoxysilane, di-n-butyldimethoxysilane, diisobutyldimethoxysilane, di-t-butyldimethoxysilane, and the like. Di-n-butyldiethoxysilane, t-butyltrimethoxysilane, dicyclohexyldimethoxysilane, dicyclohexyldiethoxysilane, cyclohexylmethyldimethoxysilane, cyclohexylmethyldiethoxysilane, cyclohexylethyldimethoxysilane, cyclohexylethyldiethoxysilane, dicyclopentyldimethoxy Silane, dicyclopentyldiethoxysilane, cyclopentylmethyldimethoxysilane, cyclopentylmethyldiethoxysilane, cyclopentylethyldiethoxysilane, cyclohexylcyclopentyldimethoxysilane, cyclohexylcyclopentyldiethoxysilane, 3-methylcyclohexylcyclopentyldimethoxysilane, 4-methylcyclohexylcyclopentyldimethoxy Silane, 3,5-dimethylcyclohexyl (cyclopentyl) dimethoxysilane, bis (ethylamino) methylethylsilane, t-butylmethylbis (ethylamino) silane, bis (ethylamino) dicyclohexylsilane, dicyclopentylbis (ethylamino) silane , Bis (methylamino) (methylcyclopentylamino) methylsilane, diethylaminotriethoxysilane, bis (cyclohexylamino) dimethoxysilane, bis (perhydroisoquinolino) dimethoxysilane, bis (perhydroquinolino) dimethoxysilane, ethyl (isoquinolino) Dimethoxysilane, bis (methylamino) dit-butylsilane, bis ( One or more selected from ethylamino) dicyclopentylsilane and bis (ethylamino) diisopropylsilane are preferred.

According to the present invention, a propylene homopolymer (homopolypropylene) having a low melting point of less than 160 ° C., maintaining a high degree of stereoregularity, and having excellent melt tension without coexistence of α-olefins other than propylene such as ethylene can be obtained. It is possible to provide a catalyst for olefin polymerization that can be produced under high polymerization activity.

In the olefin polymerization catalyst according to the present invention, the content ratios of the solid catalyst component, the organoaluminum compound and the external electron donating compound can be arbitrarily selected within the range in which the effect of the present invention can be obtained, and are not particularly limited.
The catalyst for polymerizing olefins according to the present invention preferably contains 1 to 2000 mol, more preferably 50 to 1000 mol, of the organoaluminum compound per 1 mol of titanium atoms in the solid catalyst component.
Further, the catalyst for olefin polymerization according to the present invention contains 1 to 200 mol of an external electron donating compound in total per 1 mol of titanium atoms in the solid catalyst component contained in the catalyst for olefin polymerization. It is preferable to contain 2 to 150 mol, more preferably 5 to 100 mol, and even more preferably.
Further, the olefin polymerization catalyst according to the present invention preferably contains 0.001 to 10 mol of the external electron donating compound in total per 1 mol of the organoaluminum compound contained in the olefin polymerization catalyst. , 0.002 to 2 mol is more preferable, and 0.002 to 0.5 mol is more preferable.

Next, a method for producing an olefin polymer according to the present invention will be described.
The method for producing an olefin polymer according to the present invention is characterized by polymerizing olefins in the presence of the catalyst for polymerizing olefins according to the present invention.

Examples of the olefins to be subjected to the polymerization include one or more selected from ethylene, propylene, 1-butene, 1-pentene, 4-methyl-1-pentene, vinylcyclohexane and the like, and ethylene, propylene and 1-. One or more selected from butene is preferable, and propylene is more preferable.

When olefins are polymerized using the olefin polymerization catalyst according to the present invention, the preparation of the olefin polymerization catalyst and the polymerization of the olefins may be carried out at the same time. Although the order of contacting the components is arbitrary, it is desirable to first charge the organic aluminum compound into the polymerization system, then contact the external electron donating compound, and then contact the solid catalyst component for olefin polymerization.
Polymerization of olefins can be carried out in the presence or absence of an organic solvent, and olefin monomers such as propylene can be used in either a gaseous or liquid state.

As a method for polymerizing olefins, a conventionally known method used for polymerizing 1-olefins having 2 to 10 carbon atoms can be used. For example, in the presence of an organic solvent, a gas or liquid monomer is supplied to carry out the polymerization. Examples thereof include slurry polymerization to be carried out, bulk polymerization in which polymerization is carried out in the presence of a liquid monomer such as liquefied propylene, and vapor phase polymerization in which polymerization is carried out in the presence of a gaseous monomer. Therefore, polymerization by vapor phase polymerization is preferable.

Further, for example, the method described in Japanese Patent No. 2578408, the continuous gas phase polymerization method described in Japanese Patent No. 4392064, Japanese Patent Application Laid-Open No. 2009-292964, and the polymerization method described in Japanese Patent No. 2766523 are also applied. It is possible to do. Each of the above polymerization methods can be performed by either a batch method or a continuous method. Further, the polymerization reaction may be carried out in one stage or in two or more stages.

When olefins are polymerized using the olefin polymerization catalyst according to the present invention, examples of the polymerization reactor include a reactor such as an autoclave with a stirrer and a flow tank, and the reactor may be granular or granulated. The powdery polymer can be accommodated in a stationary phase and moved using a stirrer or a fluidized bed.

The molecular weight of the polymer to be obtained can be adjusted and set in a wide range by adding a modifier commonly used in the polymerization technique, for example, hydrogen.
In addition, in order to remove the heat of polymerization, a liquid easily volatile hydrocarbon, for example, butane may be supplied and vaporized in the polymerization zone.

The polymerization temperature is preferably 200 ° C. or lower, more preferably 100 ° C. or lower, and even more preferably 50 to 90 ° C.
The polymerization pressure is preferably normal pressure to 10 MPa, more preferably normal pressure to 5 MPa, still more preferably 1 to 4 MPa.

In the method for producing an olefin polymer according to the present invention, the obtained olefin polymer preferably has a melt fluidity (melt flow rate (MFR)) of 1 kg / 10 minutes or more, preferably 1 to 5 kg / 10. Minutes are more preferred, and 2-4 kg / 10 mins are even more preferred.
When the fluidity at the time of melting is in the above range, a film or the like can be easily formed from the obtained polymer.

In addition, in this application document, the fluidity at the time of melting of an olefin polymer means the value measured by the JIS K 7210 B method.

In the method for producing an olefin polymer according to the present invention, the obtained olefin polymer preferably has a melting point (Tm) of less than 160 ° C., and more preferably 157 to 160 ° C.
In this application document, the melting point (Tm) of the olefin polymer means a value measured by the JIS K7121 method.

In the method for producing an olefin polymer according to the present invention, the obtained olefin polymer preferably has an isotactic pentad fraction (NMR-mm mm) measured by ¹³ C-NMR of 91% or more. , 91.5% or more, more preferably 91.5 to 95.0%.

Pentad means a unit chain consisting of four adjacent monomer units inserted by selecting the same prochiral plane, and isotactic pentad means a unit consisting of four adjacent propylene units having an isotactic structure. Means a chain. Further, in the present invention, the isotactic pentad fraction is expressed as a percentage of the total number of pentads in the olefin chain portion of the polymer constituting the isotactic polypropylene-based particles (A). The upper limit that can be measured is 100%.

When the isotactic pentad fraction (NMR-mm mm) of the polymer at a melting point (Tm) of less than 160 ° C. is within the above range, it becomes possible to maintain stereoregularity, and the melt tension (koshi) of polypropylene becomes possible. Is improved, and "dripping" when the polymer is formed into a film is alleviated, so that the processability to a film or the like can be improved.

In this application document, the isotactic pentad fraction (mm mm) of the polymer was determined by measuring the ¹³ C-NMR spectrum and A.I. Zambelli; means values determined according to the methods described in Macromolecules, 6,925 (1973), 8,687 (1975) and 13,267 (1980).

According to the present invention, by homopolymerizing propylene using the olefin polymerization catalyst according to the present invention, the melting point is as low as less than 160 ° C. It is possible to provide a method for producing a propylene homopolymer (homopolypropylene), which maintains a high degree of property and is excellent in melt tension.

(Example)
Next, the present invention will be described in more detail with reference to examples, but this is merely an example and does not limit the present invention.

(Example 1)
1. 1. Preparation of solid catalyst components To a flask equipped with a stirrer and sufficiently replaced with nitrogen gas and having an internal volume of 500 ml, 10 g (87.4 mmol) of diethoxymagnesium, 45 ml of toluene and 30 ml of titanium tetrachloride were added, and then diphthalate was added. 6.6 mmol (1.8 g) of normal butyl was added, the temperature was raised to 100 ° C., and the reaction was carried out for 120 minutes while maintaining the temperature of 100 ° C. After completion of the reaction, the reaction product was washed 3 times with 90 ml of toluene at 100 ° C.
Next, 90 ml of toluene and 2 mmol of dimethyl diisobutylmalonate (0.5 g, 0.023 mol per mol of magnesium atom contained in magnesium) were added, the temperature was raised to 100 ° C, and the reaction was carried out for 5 minutes while maintaining 100 ° C. After that, the supernatant was removed.
Next, 55 ml of toluene (a mixed solution of 22.5 ml of titanium tetrachloride and 32.5 ml of toluene) containing 40% by volume of titanium tetrachloride was newly added, the temperature was raised to 100 ° C., and the mixture was stirred at 100 ° C. for 5 minutes. After repeating the operation of removing the supernatant twice, it was washed 6 times with 55 ml of n-heptane at 40 ° C. to obtain a solid catalyst component-containing solution.
The solid and liquid of this solid catalyst component-containing liquid are separated, and the titanium content, the first internal electron donating compound content and the second internal electron donating compound content in the obtained solid component (solid catalyst component) are contained. When the amounts were measured, they were 4.4% by mass, 9.6% by mass, and 2.7% by mass, respectively.

The titanium content in the solid content, the content of the first internal electron donating compound and the content of the second internal electron donating compound were measured as follows.
<Titanium content in solid content>
The titanium content in the solid content was measured according to the method of JIS M 8301.
<Contents of internal electron donating compound in solid content>
The content of the internal electron donating compound was determined by measuring under the following conditions using gas chromatography (manufactured by Shimadzu Corporation, GC-14B). In addition, the number of moles of each component was determined from the measurement results of gas chromatography using a calibration curve measured in advance at a known concentration.
(Measurement condition)
-Column: Packed column (φ2.6 x 2.1 m, Silicone SE-30 10%, Chromosorb WAW DMCS 80/100, manufactured by GL Sciences Co., Ltd.)
-Detector: FID (Flame Ionization Detector, hydrogen flame ionization detector)
-Carrier gas: helium, flow rate 40 ml / min-Measurement temperature: vaporization chamber 280 ° C, column 225 ° C, detector 280 ° C

2. 2. Formation of Polymerization Catalyst and Polymerization In an autoclave with a stirrer having an internal volume of 1.5 liters completely replaced with propylene gas, 700 mL of heptane, 2.1 mmol of triethylaluminum, 0.0525 mmol of cyclohexylmethyldiethoxysilane (CMDMS) and the above. The solid catalyst component was charged in 0.0525 mmol as a titanium atom to form a polymerization catalyst. Then, 10 ml of hydrogen gas was added, prepolymerization was carried out at 20 ° C. for 30 minutes, the temperature was raised, and slurry polymerization was carried out at 70 ° C. for 120 minutes. At this time, the polymerization activity per 1 g of the solid catalyst component, the melt flow rate (MFR) in the produced polymer, the melting point (Tm) of the polymer, and the isotactic pentad (mm mm) of the polymer are determined by the following methods. It was measured. The results are shown in Table 1.

<Polymerization activity per 1 g of solid catalyst component>
The polymerization activity per 1 g of the solid catalyst component was calculated by the following formula.
Polymerization activity (g-pp / g-catalyst) = mass of polymer (g) / mass of solid catalyst component (g)

<Polymer melt flowability (MFR)>
The melt flow rate (MFR) indicating the melt flow property of the polymer was measured according to ASTM D 1238 and JIS K 7210.

<Melting point of polymer (Tm)>
The temperature at the position of the maximum peak in the endothermic curve of differential scanning calorimetry (DSC) was defined as the melting point (Tm) of the polymer. In the measurement, the sample is packed in an aluminum pan, heated to 250 ° C. at 10 ° C./min by differential scanning calorimetry (DSC) (EXSTAR6000, manufactured by SII), held at 250 ° C. for 20 minutes, and then 5 ° C./. The endothermic curve when the temperature was lowered to 20 ° C. in minutes and then raised to 10 ° C./min was measured, and the temperature at the position of the maximum peak in the endothermic curve was defined as the melting point (Tm) of the polymer.

<Polymer isotactic pentad (mm mm)>
The isotactic pentad (mm mm) of the polymer was measured by ¹³ C-NMR spectrum and A.I. Zambelli; Macromolecules, 6,925 (1973), 8,687 (1975) and 13,267 (1980). The ¹³ C-NMR measurement was carried out using JNM-ECA400 manufactured by JEOL Ltd. under the following conditions.
< ¹³ C-NMR measurement conditions>
Measurement mode: Proton decoupling method
Pulse width: 7.25 μsec
Pulse repetition time: 7.4 sec
Accumulation number: 10,000 times
Solvent: Tetrachloroethane-d2
Sample concentration: 200 mg / 3.0 ml

(Example 2)
In "2. Formation and Polymerization of Polymerization Catalyst" of Example 1, polymerization was carried out in the same manner as in Example 1 except that 0.0525 mmol of cyclohexylmethyldiethoxysilane (CMDMS) was changed to 0.105 mmol. .. At this time, the values of the polymerization activity per 1 g of the solid catalyst component, the melt flow rate (MFR) in the produced polymer, the melting point (Tm) of the polymer, and the isotactic pentad (mm mm) of the polymer are shown in Example 1. It was measured by the same method. The results are shown in Table 1.

(Example 3)
In "2. Formation and Polymerization of Polymerization Catalyst" of Example 1, polymerization was carried out in the same manner as in Example 1 except that 0.0525 mmol of cyclohexylmethyldiethoxysilane (CMDMS) was changed to 0.173 mmol. At this time, the values of the polymerization activity per 1 g of the solid catalyst component, the melt flow rate (MFR) in the produced polymer, the melting point (Tm) of the polymer, and the isotactic pentad (mm mm) of the polymer are shown in Example 1. It was measured by the same method. The results are shown in Table 1.

(Example 4)
In "1. Synthesis of solid catalyst component" of Example 1, the solid catalyst component was synthesized in the same manner as in Example 1 except that 2 mmol of diethyl diisobutyl malonate was changed to 1 mmol. The solid and liquid of this solid catalyst component were separated, and the titanium content, the dinormal butyl phthalate content and the diethyl diisobutyl malonate content in the obtained solid content were measured and found to be 4.6% by mass, respectively. It was 10.0% by mass and 1.2% by mass. Using this solid catalyst component, a polymerization catalyst was formed and polymerized in the same manner as in Example 1. At this time, the values of the polymerization activity per 1 g of the solid catalyst component, the melt flow rate (MFR) in the produced polymer, the melting point (Tm) of the polymer, and the isotactic pentad (mm mm) of the polymer are shown in Example 1. It was measured by the same method. The results are shown in Table 1.

(Example 5)
In "2. Formation and Polymerization of Polymerization Catalyst" of Example 4, polymerization was carried out in the same manner as in Example 1 except that 0.0525 mmol of cyclohexylmethyldiethoxysilane (CMDMS) was changed to 0.105 mmol. At this time, the values of the polymerization activity per 1 g of the solid catalyst component, the melt flow rate (MFR) in the produced polymer, the melting point (Tm) of the polymer, and the isotactic pentad (mm mm) of the polymer are shown in Example 1. It was measured by the same method. The results are shown in Table 1.

(Example 6)
In "2. Formation and Polymerization of Polymerization Catalyst" of Example 4, polymerization was carried out in the same manner as in Example 1 except that 0.0525 mmol of cyclohexylmethyldiethoxysilane (CMDMS) was changed to 0.1575 mmol. At this time, the values of the polymerization activity per 1 g of the solid catalyst component, the melt flow rate (MFR) in the produced polymer, the melting point (Tm) of the polymer, and the isotactic pentad (mm mm) of the polymer are shown in Example 1. It was measured by the same method. The results are shown in Table 1.

(Example 7)
1. 1. Synthesis of solid catalyst component In "1. Synthesis of solid catalyst component" of Example 1, the solid catalyst component was synthesized in the same manner as in Example 1 except that 2 mmol of dimethyl diisobutylmalonate was changed to 1 mmol of diethyl phthalate. rice field. The solid and liquid of the obtained solid catalyst component-containing liquid were separated, and the titanium content, dinormal butyl phthalate content and diethyl phthalate content in the obtained solid content (solid catalyst component) were measured. , 4.9% by mass, 9.0% by mass, and 1.5% by mass, respectively.
2. 2. Formation and Polymerization of Polymerization Catalyst In "2. Formation and Polymerization of Polymerization Catalyst" of Example 1, the above 1. Using the solid catalyst component obtained in 1 above, a polymerization catalyst was formed and polymerized in the same manner as in Example 1 except that 0.0525 mmol of cyclohexylmethyldiethoxysilane (CMDMS) was changed to 0.021 mmol.
At this time, the values of the polymerization activity per 1 g of the solid catalyst component, the melt flow rate (MFR) in the produced polymer, the melting point (Tm) of the polymer, and the isotactic pentad (mm mm) of the polymer are shown in Example 1. It was measured by the same method. The results are shown in Table 1.

(Example 8)
Examples except that in "2. Formation and Polymerization of Polymerization Catalyst" of Example 7, 0.021 mmol of cyclohexylmethyldiethoxysilane (CMDMS) was changed to 0.105 mmol and the amount of hydrogen was changed from 10 ml to 20 ml. Polymerization was carried out in the same manner as in 7.
At this time, the values of the polymerization activity per 1 g of the solid catalyst component, the melt flow rate (MFR) in the produced polymer, the melting point (Tm) of the polymer, and the isotactic pentad (mm mm) of the polymer are shown in Example 1. It was measured by the same method. The results are shown in Table 1.

(Example 9)
In "2. Formation and Polymerization of Polymerization Catalyst" of Example 7, polymerization was carried out in the same manner as in Example 7 except that 0.021 mmol of cyclohexylmethyldiethoxysilane (CMDMS) was changed to 0.173 mmol. At this time, the values of the polymerization activity per 1 g of the solid catalyst component, the melt flow rate (MFR) in the produced polymer, the melting point (Tm) of the polymer, and the isotactic pentad (mm mm) of the polymer are shown in Example 1. It was measured by the same method. The results are shown in Table 1.

(Comparative Example 1)
In "1. Synthesis of solid catalyst component" of Example 1, instead of adding 90 ml of toluene and 2 mmol of dimethyl diisobutyl malonate, only 90 ml of toluene was added and diethyl diisobutyl malonate was not added. The solid catalyst component was synthesized in the same manner as in Example 1. The solid and liquid of the obtained solid catalyst component-containing liquid were separated, and the titanium content and the phthalic acid diester content in the obtained solid content (solid catalyst component) were measured and found to be 2.5% by mass, respectively. And 10.9% by mass.
Using this solid catalyst component, a polymerization catalyst was formed and polymerized in the same manner as in Example 1 except that the amount of cyclohexylmethyldiethoxysilane (CMDMS) added was changed from 0.0525 mmol to 0.021 mmol.
At this time, the values of the polymerization activity per 1 g of the solid catalyst component, the melt flow rate (MFR) in the produced polymer, the melting point (Tm) of the polymer, and the isotactic pentad (mm mm) of the polymer are shown in Example 1. It was measured by the same method. The results are shown in Table 1.

From Table 1, in Examples 1 to 9, since the solid catalyst component for olefin polymerization according to the present invention is used, the polymer has a low melting point of less than 160 ° C. under high polymerization activity, but ¹³ It was found that a polypropylene having a high isotactic pentad fraction (NMR-mm mm) measured by C-NMR and capable of maintaining a high degree of stereoregularity can be obtained, and such polypropylene is molded into a film. Since the melt tension (stiffness) becomes high, it can be seen that "dripping" during film forming can be improved and the amount of sticky component can be suppressed.

On the other hand, from Table 1, in Comparative Example 1, since the solid catalyst component for olefin polymerization is not a specific one containing a predetermined amount of the second internal electron donating compound together with the first internal electron donating compound. The formation of non-stereospecific active points in the solid catalyst component is not suppressed, and reaction by-products and excess titanium components remain in the solid catalyst component, so that the melting point is in the region of less than 160 ° C. In ¹³ C-NMR, the isotactic pentad fraction (NMR-mmmm) measured by C-NMR was reduced to less than 91%, so that the melt tension (stiffness) when used in film production was low. In addition, it can be seen that the amount of sticky component at the time of molding increases.

According to the present invention, a propylene homopolymer (homopolypolymer) having a low melting point of less than 160 ° C., a high degree of steric regularity, and an excellent melt tension can be obtained without coexistence of α-olefins other than propylene such as ethylene. It is possible to provide a solid catalyst component for olefin polymerization, a method for producing a solid catalyst component for olefin polymerization, a method for producing a catalyst for olefin polymerization, and a method for producing an olefin polymer, which can be produced under high polymerization activity.

Claims (7)

The first step of contacting a magnesium compound, a titanium halogen compound, and a first internal electron donating compound, reacting them, and then washing them.
After contacting and reacting the obtained product with a second internal electron donating compound of 0.001 to 0.1 mol per mol of magnesium atom contained in the magnesium compound in the presence of a hydrocarbon solvent. , A second step of removing the hydrocarbon solvent,
The third step of washing once or more with an organic solvent containing a titanium halogen compound of more than 5% by volume and 50% by volume or less and the fourth step of washing once or more with an organic solvent not containing a titanium halogen compound are sequentially performed . ,
The first internal electron donating compound is a phthalic acid diester.
The second internal electron donating compound is an alkyl-substituted malonic acid diester.
A method for producing a solid catalyst component for olefin polymerization . (I) A solid catalyst component for olefin polymerization obtained by the production method according to claim 1 , and (II) the following general formula (1);
R ¹ _p AlQ _3-p (1)
(In the formula, R ¹ is an alkyl group having 1 to 6 carbon atoms, Q is a hydrogen atom or a halogen atom, p is a real number of 0 <p ≦ 3, and when there are a plurality of R ¹ , each R ¹ is It may be the same or different, and when a plurality of Qs are present, each Q may be the same or different). Method of manufacturing a catalyst for use. (III) The method for producing a catalyst for polymerizing olefins according to claim 2 , wherein the external electron donating compound is brought into contact with the catalyst. The (III) external electron donating compound is the following general formula (2);
R ² _q Si (OR ³ ) _4-q (2)
(In the formula, R ² is an alkyl group having 1 to 12 carbon atoms, a cycloalkyl group having 3 to 12 carbon atoms, a phenyl group, a vinyl group, an allyl group, an aralkyl group, an alkylamino group having 1 to 12 carbon atoms or a carbon. It is a dialkylamino group having the number 1 to 12, and when a plurality of R ^2s are present, each R ² may be the same or different. R ³ is an alkyl group having 1 to 4 carbon atoms and 3 carbon atoms. It is a cycloalkyl group, a phenyl group, a vinyl group, an allyl group or an aralkyl group of up to 6, and when a plurality of R ^3s are present, each R ³ may be the same or different. Q is 0 ≦ q ≦. It is an integer of 3.)
The method for producing a catalyst for polymerizing olefins according to claim 3 , which is one or more organosilicon compounds selected from the above. A method for producing an olefin polymer, which comprises polymerizing olefins in the presence of a catalyst for polymerizing olefins obtained by the production method according to any one of claims 2 to 4 . The method for producing an olefin polymer according to claim 5 , wherein the olefin is propylene. Claim 5 or the obtained olefin polymer has a melt flow rate of 1.0 kg / 10 minutes or more , a melting point in the range of 157 to 160 ° C. , and an isotactic pentad fraction of 91.0% or more. The method for producing an olefin polymer according to claim 6 .