JPH05202132A - Production of polypropylene - Google Patents

Abstract

(57) [Summary] (Revised) [Structure] (A) Catalyst component which essentially contains Mg compound and Ti compound (B) Ia, IIa, IIb, IIIb, IV
In the presence of a catalyst composed of at least one organometallic compound of group b metal and (C) an electron donating compound, propylene is polymerized to give a compound represented by the general formula (1): The benzoic acid compound represented by (R _{1 to} R ₅ are H, C 1 to
8 alkyl groups, C1-8 alkoxyl groups, halogen groups, amino groups, nitro groups, phenyl groups), or acid anhydrides thereof, or component (B) is further added to continue the polymerization of propylene. Method for producing polypropylene. [Effect] Polypropylene having excellent rigidity and transparency and good workability can be obtained.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a method for polymerizing propylene. Specifically, it is a method for producing polypropylene having more excellent crystallinity and transparency by using a benzoic acid compound in a polymerization system.

[0002]

2. Description of the Prior Art Polypropylene has been in great demand in recent years due to its excellent physical properties.

Along with this increase in demand, the polypropylene production technology has made remarkable progress, and as a catalyst for polymerization, a highly active catalyst having a titanium compound supported on a magnesium compound has been developed as compared with a conventional titanium trichloride-type catalyst. As for the process, more streamlined bulk polymerization method and vapor phase polymerization method are being adopted.

However, depending on the application, the products according to the known technology are not sufficiently satisfactory. A method of adding a nucleating agent has been widely used as a method for improving the rigidity of a product. For example, a metal salt of a carboxylic acid, a metal salt of an aromatic carboxylic acid, a metal salt of an aromatic phosphoric acid, a dibenzylidene sorbitol-based compound and the like can be mentioned. However, the addition of these nucleating agents is still insufficient for improving the rigidity.

On the other hand, the method of blending the nucleating agent with the polymer is to mix for a required time with a generally used Henschel mixer, V blender, ribbon blender, Banbury mixer, kneader blender or the like. It is granulated with a normal extruder. However, in these methods, there is a problem that the physical properties of the product vary due to poor dispersion of the nucleating agent, and a compounding step is required, and the energy cost consumed in the compounding step is considerable.

[0006] Further, a method of producing highly rigid polypropylene by a so-called multi-stage polymerization method by devising polymerization is proposed. For example, a method for producing a polymer in two steps of a high molecular weight portion and a low molecular weight portion in JP-A-58-201206 and JP-A-58-219207, and JP-A-60-49008 and JP-A-60-49008. In JP-A-62-124108 and JP-A-62-195007, a method of producing a polymer in three steps is proposed.

However, in these proposals, the catalyst specifically disclosed is a titanium trichloride-type catalyst that has been used for a long time, and since the polymerization activity is low, a so-called deashing step is provided to color the product. It is necessary to avoid such problems.

[0008]

Means for Solving the Problems As a result of intensive investigations by the present inventors to solve the problems of the prior art,
Using a high activity catalyst in which a titanium compound is supported on a magnesium compound, when propylene is polymerized, ethylene,
And / or after polymerizing the α-olefin, a benzoic acid compound or a benzoic anhydride is added to the polymerization system so as to be 0.001 to 1 part by weight with respect to 100 parts by weight of the final polymer obtained. As a result, crystallinity and
It was found that polypropylene having excellent transparency can be obtained, and the present invention has been completed.

That is, according to the present invention, (A) a catalyst component containing a magnesium compound and a titanium compound as essential components, and (B) a component of the periodic table, Ia, IIa, IIb,
When polymerizing propylene in the presence of a catalyst comprising at least one selected from organometallic compounds of Group IIIb and IVb metals and an electron-donating compound as the component (C), at least 0.1 g per 1 g of the catalyst component (A). After polymerizing 1 g of ethylene and / or α-olefin, the general formula (1)

[0010]

[Chemical 5] A benzoic acid compound represented by
_{1 to} R ₅ represent hydrogen, an alkyl group having 1 to 8 carbon atoms, an alkoxyl group having 1 to 8 carbon atoms, a halogen group, an amino group, a nitro group or a phenyl group) or the general formula (2).

[0011]

[Chemical 6] A benzoic anhydride represented by the formula (provided that the substituent of the compound, R
_{6 to} R _{15 each} represent hydrogen, an alkyl group having 1 to 8 carbon atoms, an alkoxyl group having 1 to 8 carbon atoms, a halogen group, an amino group, a nitro group, or a phenyl group).
0.001 to 1 part by weight relative to 100 parts by weight, or the benzoic acid compound or the benzoic anhydride and the component (B) are added to continue the polymerization of propylene. And a method for producing polypropylene.

The catalyst used in the present invention is not particularly limited as long as it is composed of a magnesium compound and a titanium compound. As an example of a catalyst, JP-A-63-300
7, JP-A-63-314210, JP-A-63-31
7502, JP-A-64-105, JP-A-1-165.
No. 608 can be exemplified. Specific examples include the following catalysts. (I) at least one member selected from the group consisting of metal magnesium, a hydroxylated organic compound, and an oxygen-containing organic compound of magnesium; (ii) an oxygen-containing organic compound of aluminum; and (iii) oxygen-containing titanium such as titanium alkoxide. Obtained by reacting (iv) an electron-donating compound and (vi) a titanium halide compound with a solid product obtained by reacting (iv) an aluminum halide with a homogeneous solution obtained by reacting an organic compound You can

When metal magnesium and an organic hydroxide compound are used in (i) above, various forms of metal magnesium can be used, that is, powder, particles, foil, ribbon, or any other form can be used. Suitable compounds are alcohols, phenols, and organic silanols.

As the alcohols, straight-chain or branched-chain aliphatic alcohols having 1 to 18 carbon atoms, alicyclic alcohols or aromatic alcohols can be used.

Examples include methanol, ethanol and n.
-Propanol, i-Propanol, n-Butanol,
n-hexanol, 2-ethylhexanol, n-octanol, i-octanol, n-stearyl alcohol
And cyclopentanol, cyclohexanol, ethylene glycol and the like. Further, examples of the phenols include phenol, cresol, xylenol and hydroquinone.

The organic silanol has at least one hydroxyl group, and the organic group has an alkyl group having 1 to 12 carbon atoms, preferably 1 to 6 carbon atoms, a cycloalkyl group, It is selected from compounds having an arylalkyl group, an aryl group, and an alkylaryl group.

For example, trimethylsilanol, triethylsilanol, triphenylsilanol, t-butyldimethylsilanol and the like can be mentioned.

These hydroxylated organic compounds may be used alone or
Used as a mixture of more than one species.

In addition, when using magnesium metal to obtain the solid catalyst component of component (A) described in the present invention, it reacts with metal magnesium or forms an addition compound for the purpose of promoting the reaction. It is desirable to add such a substance, for example, a polar substance such as iodine, mercuric chloride, an alkyl halide and an organic acid, either alone or in combination of two or more.

Next, as compounds belonging to the oxygen-containing organic compound of magnesium, magnesium alkoxides such as methylate, ethylate and isopropylate are used.
, Decanolate, methoxyethylate and cyclohexanolate, magnesium alkyl alkoxides such as ethyl ethylate, magnesium hydroalkoxides such as hydroxymethylate, magnesium phenoxides such as phenate, naphthenate. , Phenanthrene and cresolate, magnesium carboxylates such as acetate, stearate, benzoate, phenylacetate, adipate, sebacate.
, Phthalates, acrylates, and oleates, oxymates such as butyl oxymate, dimethylglyoxymate and cyclohexyl oxymate, hydroxamates, hydroxylamine salts such as N-nitroso-. Examples thereof include N-phenyl-hydroxylamine derivatives, enolates such as acetylacetonate, magnesium silanolates such as triphenylsilanolate. These oxygen-containing organomagnesiums are used alone or as a mixture of two or more kinds.

The oxygen-containing organic compound of aluminum, which is the reactant of (ii) above, has a general formula of Al (OR ¹ ).
An oxygen-containing organic compound represented by _m X _3-m is used. However, in the general formula, R ¹ has 1 to 2 carbon atoms.
It represents 0, preferably 1 to 10 hydrocarbon groups. As such a hydrocarbon group, a linear or branched alkyl group,
Examples thereof include a cycloalkyl group, an arylalkyl group, an aryl group and an alkylaryl group. m
Represents a number satisfying 0 <m ≦ 3, and X represents a halogen atom.

Specific examples of the oxygen-containing organic compound of aluminum include trimethoxyaluminum, triethoxyaluminum, tri-n-propoxyaluminum, tri-i-propoxyaluminum, tri-n-butoxyaluminum and tri-sec-butoxyaluminum. ，
Tri-tert-butoxyaluminum, tri (2-ethylhexoxy) aluminum, triphenoxyaluminum, tribenzyloxyaluminum, dichloromethoxyaluminum, chlorodimethoxyaluminum,
Examples thereof include dichloro (2-ethylhexoxy) aluminum, chlorodi (2-ethylhexoxy) aluminum, dichlorophenoxyaluminum and chlorodiphenoxyaluminum. The use of oxygen-containing organic compounds of aluminum having several different hydrocarbon groups is also within the scope of the invention.

These oxygen-containing organic compounds of aluminum are used alone or as a mixture of two or more kinds.

The oxygen-containing organic compound of titanium, which is the above-mentioned (iii) reactant, can be represented by the general formula [O _p Ti _u (OR
² ) A compound represented by _q ] _n is used. However, in the general formula, R ² has 1 to 20 carbon atoms, preferably 1
The hydrocarbon groups of 10 are shown.

Examples of such a hydrocarbon group include a straight chain or branched chain alkyl group, a cycloalkyl group, an arylalkyl group, an aryl group and an alkylaryl group. p, q and u are p ≧ 0, q> 0, u ≧ 1
Represents the number compatible with the valence of Ti, and n represents an integer.
Above all, it is desirable to use an oxygen-containing organic compound of titanium such that 0 ≦ p ≦ 1, 1 ≦ u ≦ 2 and 1 ≦ n ≦ 6.

As specific examples, titanium tetramethoxide, titanium tetraethoxide, titanium tetra-n-propoxide, titanium tetra-i-propoxide, titanium tetra-n-butoxide, titanium tetra-i-butoxide, tetra ( n-nonyl) titanate, tetra (2-ethylhexyl) titanate, tetracresyl titanate
And hexa-i-propoxydititanate. The use of oxygen-containing organic compounds of titanium having several different hydrocarbon groups is also within the scope of the invention. These oxygen-containing organic compounds of titanium may be used alone,
It is also possible to use them after mixing or reacting two or more kinds.

The aluminum halide compound which is the above-mentioned (iv) reactant is represented by the general formula AlR ³ _r X _3-r.
The one shown in is used. In the formula, R ³ represents a hydrocarbon group having 1 to 20 carbon atoms, X represents a halogen atom, and r represents a number 0 <r ≦ 2. R ³ is preferably selected from linear or branched alkyl groups, alkoxy groups, cycloalkyl groups, arylalkyl groups, aryl groups and alkylaryl groups. The aluminum halide compound is used alone or as a mixture of two or more kinds.

Specific examples of aluminum halides include, for example, ethyl aluminum dichloride, n-propyl aluminum dichloride, n-butyl aluminum dichloride, i-butyl aluminum dichloride, sesquiethyl aluminum chloride, sesqui-i.
-Butyl aluminum chloride, sesqui-i-propyl aluminum chloride, sesqui-n-propyl aluminum chloride, diethyl aluminum chloride, di-i-propyl aluminum chloride, di-n
-Propyl aluminum chloride, di-i-butyl aluminum chloride, diethyl aluminum bromide, diethyl aluminum iodide and the like.

The electron-donating compound which is the above-mentioned (v) reactant is an ether, an ester, a ketone or a phenol.
, Amine, amide, imine, nitrile, phosphine,
Mention may be made of phosphites, stibines, arsines, phosphorylamides and alcoholates. Of these, esters are preferred, and organic acid esters are most preferred.

Examples of the organic acid esters include aromatic carvone mono- or diesters and aliphatic carboxylic acid mono- or diesters.

Specific examples thereof include butyl formate, ethyl acetate, butyl acetate, isobutyl isobutyrate, propyl pivalate, isobutyl pivalate, ethyl acrylate, methyl methacrylate, ethyl methacrylate, isobutyl methacrylate, malonic acid. Diethyl, diisobutyl malonate, diethyl succinate, dibutyl succinate, diisobutyl succinate, diethyl glutarate, dibutyl glutarate, diisobutyl glutarate, diisobutyl adipate, dibutyl sebacate, diethyl maleate, dibutyl maleate, diisobutyl maleate, Monomethyl fumarate, diethyl fumarate, diisobutyl fumarate, diethyl tartrate, dibutyl tartrate, diisobutyl tartrate, methyl benzoate, ethyl benzoate, methyl p-toluate, p-toluy Ethyl, p-tert-butyl benzoate, ethyl p- anisic acid, alpha-naphthoic acid isobutyl, ethyl cinnamate, monomethyl phthalate,
Dibutyl phthalate, diisobutyl phthalate, dihexyl phthalate, dioctyl phthalate, di2-ethylhexyl phthalate, diallyl phthalate, diphenyl phthalate, diethyl isophthalate, diisobutyl isophthalate, diethyl terephthalate, dibutyl terephthalate, diethyl naphthalate. , Dibutyl naphthalate and the like. The electron donating compound (v) is used alone or as a mixture of two or more kinds.

As the titanium halide compound which is the above-mentioned (vi) reactant, the general formula Ti (OR ⁴ ) _f X _{4-f is used.}
A titanium compound represented by In the formula, R ⁴ is 1
Represents a hydrocarbon group having ˜20 carbon atoms, X represents a halogen atom, and f represents a number 0 ≦ f <4. R ⁴
Is preferably selected from linear or branched alkyl groups, alkoxy groups, cycloalkyl groups, arylalkyl groups, aryl groups and alkylaryl groups. The titanium halide compound may be used alone or as a mixture of two or more kinds.

Specific examples of the titanium halide compound include titanium tetrachloride, ethoxy titanium trichloride, propoxy titanium trichloride, butoxy titanium trichloride, phenoxy titanium trichloride, diethoxy titanium dichloride, triethoxy titanium chloride and the like. Is mentioned.

The solid catalyst component obtained in the present invention was obtained by reacting the homogeneous solution obtained by reacting the above-mentioned reaction agents (i), (ii) and (iii) with the reaction agent (iv). The solid product can then be prepared by reacting the reactants (v), (vi). In this case, (i)
It is preferable to use a surfactant in addition to each of the components (vi). Examples of the surfactant used include anionic surfactants, cationic surfactants, nonionic surfactants, amphoteric surfactants and fluorochemical surfactants. Of these, nonionic surfactants are most preferable. Examples thereof include polyoxyethylene lauryl ether, polyoxyethylene cetyl ether, sorbitan monolaurate and sorbitan distearate.

These reactions are preferably carried out in a liquid medium. Therefore, it should be carried out in the presence of an inert organic solvent, especially if these reactants themselves are not liquid at the operating conditions, or if the amount of liquid reactant is insufficient. As the inert organic solvent, any of those commonly used in the art can be used, and examples thereof include aliphatic, alicyclic or aromatic hydrocarbons, halogen derivatives thereof, or a mixture thereof.

For example, isobutane, pentane, isopentane, hexane, heptane, cyclohexane, benzene,
Toluene, xylene, chlorobenzene, 1,2-dichlorobenzene, 1,3-dichlorobenzene, benzyl chloride, methylene dichloride, 1,2-dichloroethane, 1,3
-Dichloropropane, 1,4-dichlorobutane, 1,
1,1, -trichloroethane, 1,1,2-trichloroethane, 1,1,1,2-tetrachloroethane, 1,
1,2,2-tetrachloroethane, tetrachloroethylene, carbon tetrachloride, chloroform and the like can be mentioned.

Even if these organic solvents are used alone,
You may use it as a mixture. By the way, when a halogen derivative or a mixture thereof is used, good results may be obtained in the polymerization activity and the stereoregularity of the polymer.

Reactants (i) and (i) used in the present invention
The amount of i), (iii), (iv), (v), (vi) used is not particularly limited, but the molar ratio of the magnesium atom (i) to the oxygen-containing organic compound (ii) of aluminum is
If it is intended to obtain polymer particles in the size of 1: 0.01 to 1:20, especially 3000 μm or more in pellet size, it is desirable to select the range of 1: 0.05 to 10.

The molar ratio of the magnesium atom (i) to the oxygen-containing organic compound of titanium (iii) is 1: 0.01.
It is preferable to select the amount used to be 1: 0.1 to 1: 5, preferably 1: 0.1 to 1: 5, in order to obtain pellet-sized polymer particles having very good powder characteristics.

The ratio of magnesium atoms to aluminum atoms in aluminum halide (iv) is 1:
0.1 to 1: 100, preferably 1: 0.1 to 1:20
It is preferable to select the amount of the reactant used so as to fall within the range. If the ratio of aluminum atoms is out of this range and is too large, the catalytic activity may be low, or good powder properties may not be obtained, or if it is too small, good powder properties may not be obtained.

The magnesium atom (i) and the electron donating compound (v) are used in a molar ratio of 1: 0.05 to 1: 5.0, preferably 1: 0.1 to 1: 2.0. It is preferable to choose the amount. Outside of these ranges, problems such as low polymerization activity and low stereoregularity of the polymer may occur. Further, the molar ratio of magnesium atom (i) to titanium halide compound (vi) is from 1: 1 to
It is preferable to select the amount of the reactant used so that it is in the range of 1: 100, preferably 1: 3 to 1:50. If the content is out of this range, problems such as low polymerization activity and coloring of the product may occur.

The reaction conditions for obtaining a homogeneous solution from the reactants (i), (ii) and (iii) are -50 to 300 ° C.
Preferably, at a temperature of 0 to 200 ° C., 0.5 to
It is carried out at normal pressure or under pressure in an inert gas atmosphere for 50 hours, preferably 1 to 6 hours. Further, at this time, by adding an electron donating compound similar to the compound (v), homogenization can be performed in a shorter time.

Further, in the reaction of the reactants (iv), (v) and (vi), it is -50 to 200 ° C., preferably -30.
The temperature is in the range of ˜150 ° C. for 0.2 to 50 hours, preferably 0.5 to 10 hours in an inert gas atmosphere at atmospheric pressure or under pressure.

The reaction conditions of the reactant (iv) are important,
It is extremely important because it plays a decisive role in controlling the particle shape and particle size of the solid product particles produced, the solid catalyst component particles, and the polymer particles obtained using them.

Further, the reaction of the reaction agent (vi) may be carried out by dividing it in multiple stages. When addition of the reaction of the reaction agent (vi), in the general formula R-CH = CH ₂ (wherein, R 1 to 10
In the presence of ethylene and / or α-olefin represented by a straight chain or branched chain substituted or unsubstituted alkyl group having 1 to 8 carbon atoms or a hydrogen atom). In these cases, an effect such as resulting in improvement of polymerization activity and stereoregularity of the polymer may be recognized.

Thus obtained solid catalyst component (A)
May be used as it is, but generally, unreacted materials and by-products that remain are removed by filtration or a decantation method, followed by thorough washing with an inert organic solvent, and then suspended in the inert organic solvent. To use. It is also possible to use a product which is isolated after washing and heated under normal pressure or reduced pressure to remove the inert organic solvent.

Further, prior to the main polymerization, a small amount of an organometallic compound component is added to give a compound of the general formula R-CH = CH ₂ (wherein R
Represents a linear or branched substituted or unsubstituted alkyl group having 1 to 10 carbon atoms, particularly 1 to 8 carbon atoms), and is a prepolymer obtained by polymerizing a small amount of α-olefin and / or ethylene. It can also be used later.

The solid catalyst component of component (A) obtained as described above is combined with the organometallic compound of component (B) and the electron-donating compound of component (C),
Used for olefin polymerization.

Examples of the organometallic compound as the component (B) include Ia, IIa, IIb, IIIb and IV of the periodic table.
At least one selected from organometallic compounds of Group b metals, such as n-butyllithium, diethylmagnesium, triethylaluminum, tri-i-butylaluminum, diethylaluminum chloride, diisobutylaluminum chloride and the like can be used.

Examples of the electron donating compound as the component (C) include
Organic acid esters, silicon-containing oxygen-containing organic compounds, nitrogen-containing organic compounds and the like are preferable. Examples of the organic acid ester include mono- or diesters of aromatic carboxylic acids and mono- or diesters of aliphatic carboxylic acids. Of these, preferred are aliphatic carboxylic acid esters and aromatic carboxylic acid esters.

Specific examples of the aliphatic carboxylic acid ester include ethyl acetate, propyl acetate, butyl acetate, ethyl propionate, butyl propionate and ethyl butyrate having 2 to 18 carbon atoms. Examples of the aromatic carboxylic acid ester include methyl benzoate, ethyl benzoate, methyl toluate, ethyl toluate, methyl anisate, ethyl anisate and the like having 1 to 24 carbon atoms. The above organic acid esters may be used alone, or may be used by mixing or reacting two or more kinds.

As the oxygen-containing organic compound of silicon, an oxygen-containing organic compound of silicon represented by the general formula R ¹ _s Si (OR ² ) _t X ^4- _{(s + t)} is used. However,
In the general formula, R ¹ and R ² are each a linear or branched alkyl group having 1 to 20 carbon atoms, preferably 1 to 10 carbon atoms, a cycloalkyl group, an arylalkyl group, an aryl group and an alkylaryl group. Represents a hydrocarbon group or hydrogen atom such as
And t represent the numbers 0 ≦ s ≦ 3, 1 ≦ t ≦ 4, 1 ≦ s + t ≦ 4, and X represents a halogen atom.

As a specific example, tetramethoxysilane,
Tetraethoxysilane, tetra-n-propoxysilane, tetra-i-propoxysilane, tetra-n-butoxysilane, tetra-i-pentoxysilane, tetra-
n-hexoxysilane, tetraphenoxysilane, tetrakis (2-ethylhexoxy) silane, tetrakis (2-ethylbutoxy) silane, tetrakis (2-methoxyethoxy) silane, methyltrimethoxysilane, ethyltrimethoxysilane, n-butyltrimethoxysilane , Phenyltrimethoxysilane, vinyltrimethoxysilane, chloromethyltrimethoxysilane, 3-chloropropyltrimethoxysilane, 4-chlorophenyltrimethoxysilane, trimethoxysilane, methyltriethoxysilane, ethyltriethoxysilane, n-propyltrimethoxysilane. Ethoxysilane, n-butyltriethoxysilane,
Phenyltriethoxysilane, vinyltriethoxysilane, 3-aminopropyltriethoxysilane, triethoxysilane, ethyltri-i-propoxysilane, vinyltri-i-propoxysilane, i-pentyltri-n
-Butoxysilane, methyltri-i-pentoxysilane, ethyltri-i-pentoxysilane, methyltri-
n-hexoxysilane, phenyltri-i-pentoxysilane, n-propyltrimethoxysilane, i-propyltrimethoxysilane, i-butyltrimethoxysilane, dimethyldimethoxysilane, methylphenyldimethoxysilane, diphenyldimethoxysilane, methyldimethoxysilane , Dimethyldiethoxysilane, diethyldiethoxysilane, diphenyldiethoxysilane, methyldodecyldiethoxysilane, methyloctadecyldiethoxysilane, methylphenyldiethoxysilane, methyldiethoxysilane, dibenzyldiethoxysisilane, diethoxysilane, Dimethyldi-n-butoxysilane, dimethyldi-i-pentoxysilane, diethyldi-i-pentoxysilane, di-i-butyldi-i-pentoxysilane, diphenyldi i- pentoxy silane, diphenyl di -n- oct silane, diisobutyl dimethoxy silane, trimethyl methoxy silane, trimethyl ethoxy silane, dimethyl silane, trimethyl -i-
Propoxysilane, trimethyl-n-propoxysilane, trimethyl-t-butoxysilane, trimethyl-i
-Butoxysilane, trimethyl-n-butoxysilane,
Examples thereof include alkoxysilanes such as trimethyl-n-pentoxysilane, trimethylphenoxysilane and the like, aryloxysilanes, haloalkoxysilanes such as dichlorodiethoxysilane, dichlorodiphenoxysilane and tribromoethoxysilane, and haloaryloxysilanes. The oxygen-containing organic compound of silicon may be used alone, or two or more kinds may be mixed or reacted and used.

Examples of the nitrogen-containing organic compound include compounds having a nitrogen atom in the molecule and having a function as a Lewis base.

Specifically, acetic acid N, N-dimethylamide, benzoic acid N, N-dimethylamide, toluic acid N,
Amide compounds such as N-dimethylamide, 2,2
6,6-tetramethylpiperidine, 2,6-diisopropylpiperidine, 2,6-diisobutylpiperidine,
2,6-diisobutyl-4-methylpiperidine, 2,
2,6-trimethylpiperidine, 2,2,6,6-tetraethylpiperidine, 1,2,2,6,6-pentamethylpiperidine, 2,2,6,6-tetramethyl-4-piperidylbenzoate , Bis (2,2,6,6-tetramethyl-4-piperidyl) sebacate and other piperidine compounds, 2,6-diisopropylpyridine, 2,6-
Pyridine compounds such as diisobutylpyridine and 2-isopropyl-6-methylpyridine, 2,2,5,5-tetramethylpyrrolidine, 2,5-diisopropylpyrrolidine, 2,2,5-trimethylpyrrolidine, 1,2,
Pyrrolidine compounds such as 2,5,5-pentamethylpyrrolidine and 2,5-diisobutylpyrrolidine, trimethylamine, triethylamine, tributylamine, tribenzylamine, tetramethylethylenediamine, diisopropylethylamine, tert-butyldimethylamine, diphenylamine, di- Amine compounds such as o-tolylamine, N, N-diethylaniline, N, N-
Examples thereof include aniline compounds such as diisopropylaniline. The above nitrogen-containing organic compounds may be used alone, or may be used by mixing or reacting two or more kinds.

These electron donating compounds may be used in combination.

The benzoic acid compound used in the present invention has the general formula (1)

[0058]

[Chemical 7] A benzoic acid compound represented by
_{1 to} R ₅ represent hydrogen, an alkyl group having 1 to 8 carbon atoms, an alkoxyl group having 1 to 8 carbon atoms, a halogen group, an amino group, a nitro group or a phenyl group), or a general formula (2).

[0059]

[Chemical 8] A benzoic anhydride represented by the formula (provided that the substituent of the compound, R
_{6 to} R _{15 each} represent hydrogen, an alkyl group having 1 to 8 carbon atoms, an alkoxyl group having 1 to 8 carbon atoms, a halogen group, an amino group, a nitro group, or a phenyl group), and in the above general formula, As the alkyl group having 1 to 8 carbon atoms, a linear alkyl group such as a methyl group, an ethyl group, a propyl group, a butyl group, an amyl group, a hexyl group, a heptyl group or an octyl group, and an i-propyl group, 1- Methylpropyl group, t-
Also included are branched alkyl groups such as a butyl group, a 3-methylamyl group, a 2-ethylhexyl group, and a 2,4-dimethylhexyl group. As the alkoxyl group having 1 to 8 carbon atoms, a linear alkyl group such as methoxy group, ethoxy group, propyloxy group, butoxy group, pentyloxy group, hexyloxy group, heptyloxy group, octyloxy group and i- Also included are branched alkyl groups such as a propyloxy group, a 1-methylpropyloxy group, a t-butoxy group, a 3-methylpentyloxy group, a 2-ethylhexyloxy group, and a 2,4-dimethylhexyloxy group. Moreover, examples of the halogen group include a fluoro group, a chloro group, a bromo group, and an iodo group. Among these, i-propyl group and t-butyl group are particularly preferable. Further, the position of the substituent may be any of the ortho position, the meta position and the para position of the carboxylic acid.

Specific examples of the benzoic acid compound include benzoic acid, p-methylbenzoic acid, m-methylbenzoic acid, o-methylbenzoic acid, p-ethylbenzoic acid, p-octylbenzoic acid and p-i-propyl. Benzoic acid, pt-butylbenzoic acid, m-t-butylbenzoic acid, p-2-ethylhexylbenzoic acid, p-fluorobenzoic acid, m-fluorobenzoic acid, o-chlorobenzoic acid, p-bromobenzoic acid , M-
Iodobenzoic acid, p-aminobenzoic acid, o-amylbenzoic acid, p-nitrobenzoic acid, p-phenylbenzoic acid, 2
-Methyl-3-ethylbenzoic acid, 2,4-di-t-butylbenzoic acid, 2,6-dimethylbenzoic acid, 2-propyl-6-amylbenzoic acid, 2,6-di-i-propylbenzoic acid 3,4-diethylbenzoic acid, 3,5-dimethylbenzoic acid, 3,5-dibutylbenzoic acid, 2,4,5-trioctylbenzoic acid, 2,4,6-trimethylbenzoic acid,
4-t-butyl-2,6-dimethylbenzoic acid, 2-propyl-4-ethyl-6-methylbenzoic acid, 2,4,5,5
6-Tetraethylbenzoic acid, 2,4-di-t-butyl-
5-Methyl-6-i-propylbenzoic acid, penta-propylbenzoic acid, 2-methyl-4-propyl-3,5,6
-Tributylbenzoic acid, 2,3-dipropyloxybenzoic acid, 2,6-dimethoxybenzoic acid, 2,3,5-trioctyloxybenzoic acid, 2-methoxy-4-propyloxy-5-ethoxybenzoic acid, 2,4,6-trimethoxybenzoic acid, 2,4,5,6-tetrabutoxybenzoic acid, penta-ethoxybenzoic acid, 2,3-difluorobenzoic acid, 2,6-difluorobenzoic acid, 2,6-dichloro Benzoic acid, 3-fluoro-5-chlorobenzoic acid, 2-
Fluoro-3-bromo-6-chlorobenzoic acid, 2,4
6-trifluorobenzoic acid, 4-chloro-2,6-difluorobenzoic acid, 2,4,5,6-tetraiodobenzoic acid, penta-fluorobenzoic acid, 2,4-diaminobenzoic acid, 2,5 -Diphenylbenzoic acid, 2,6-dihydroxybenzoic acid, 3,5-dinitrobenzoic acid, 2,3,4
-Trihydroxybenzoic acid, 2,4,5-triaminobenzoic acid, 2,4,5,6-tetrahydroxybenzoic acid,
2-Methyl-3-ethoxybenzoic acid, 2-methyl-6-
Fluorobenzoic acid, 2-propyl-3-chloro-5-hydroxybenzoic acid, 4-phenyl-2,5-t-butylbenzoic acid, 2,4-dibutoxy-6-aminobenzoic acid,
2,5-diethyl-4-nitro-6-methoxybenzoic acid and the like can be mentioned.

Examples of these anhydrides are benzoic anhydride, m-methylbenzoic anhydride, p-octylbenzoic anhydride, p-i-propylbenzoic anhydride and p-octylbenzoic anhydride.
-T-butylbenzoic anhydride, p-fluorobenzoic anhydride, o-amylbenzoic anhydride, 2-methyl-3-ethylbenzoic anhydride, 2,4-di-t-butylbenzoic anhydride , 2,6-Dimethylbenzoic anhydride, 2-methyl-4,6-diethylbenzoic anhydride, 2,4-di-t-
Butyl-5-methyl-6-i-propylbenzoic anhydride, 2-methyl-4-propyl-3,5,6-tributylbenzoic anhydride, 2,4-diethylbenzoic anhydride,
2,4,6-trimethoxybenzoic anhydride, 2,6-difluorobenzoic anhydride, 2,4,5,6-tetrayo-
Debenzoic anhydride, 2,5-diphenylbenzoic anhydride, 2,3,4-trihydroxybenzoic anhydride, 2-
Methyl-6-fluorobenzoic anhydride, 2,4-dibutoxy-6-aminobenzoic anhydride and the like can be mentioned.

If necessary, these benzoic acid compounds,
And, the benzoic anhydride can be used alone or in combination of two or more kinds. In some cases, benzoic anhydride is preferable from the viewpoint of workability.

The organometallic compound as the component (B) is used in the reactor 1
0.02 to 50 mmol, preferably 0.2
Use at a concentration of ~ 5 mmol.

The electron-donating compound as the component (C) is used in a concentration of 0.001 to 50 mmol, preferably 0.01 to 5 mmol, per liter of the reactor.

The mode of feeding the three components into the polymerization vessel in the present invention is not particularly limited. For example, the catalyst components (A), (B) and (C) are separately fed into the polymerization vessel. A method of feeding, or a method of bringing the catalyst components (A) and (C) into contact with each other and then bringing them into contact with the component (B) to polymerize,
A method of contacting the component (B) with the component (C) and then contacting with the catalyst component (A) to polymerize the catalyst component (A) in advance
It is possible to employ a method in which the component (B) and the component (C) are brought into contact with each other to perform polymerization.

When at least 0.1 g to 100 g of polymer is produced per 1 g of the catalyst component (A), a prepolymerization method known in the art can be adopted. In this case, a small amount of the organometallic compound component is added, and the general formula RC
Α-olefin and / or ethylene represented by H═CH ₂ (wherein R represents a linear or branched, substituted or unsubstituted alkyl group having 1 to 10, particularly 1 to 8 carbon atoms). It can also be used after preparing a small amount of a prepolymerized product. In addition, during the prepolymerization, these monomers are
You may use more than one kind.

The amount of the benzoic acid compound added is in the range of 0.001 to 1 part by weight based on 100 parts by weight of the obtained polymer. When the amount is less than 0.001 part by weight, the effect of improving the rigidity and the effect of improving the transparency of the obtained polymer are low, and even when the amount exceeds 1 part by weight, the effect is not changed. The preferred addition amount is 0.005 to 0.2 part by weight.

The benzoic acid compound may be added as it is to the polymerization system, or it may be added by suspending and dissolving the benzoic acid compound in an inert organic solvent.

The benzoic acid compound can be added at any time from 0.1 g per 1 g of the catalyst component (A) to 95% by weight of the final polymer, although it can be added at any time. It is preferable to add it until 80% by weight is formed. Therefore, specifically, it is preferable to add 0.1 g to 100 g of the polymer per 1 g of the catalyst component (A) after the prepolymerization or at an appropriate stage before the start of the final polymerization stage in the multistage polymerization.
When the benzoic acid compound is added to the polymerization system, (B)
The component organometallic compound may be added at the same time. In this case, the added amount of the component (B) is 0.0
It is used at a concentration of 1 to 25 mmol, preferably 0.2 to 3 mmol.

For the polymerization of propylene, any of gas phase polymerization, bulk polymerization and suspension polymerization can be adopted at a reaction temperature lower than the melting point of the polymer. Further, it can be carried out by multi-stage polymerization of two or more stages.

When the polymerization is carried out in the liquid phase, propylene itself can be used as the reaction medium, but gas phase polymerization is preferred.

The polymerization reaction conditions are not particularly limited as long as the reaction temperature is lower than the melting point of the polymer, but the reaction temperature is usually 20 to 110 ° C. and the pressure is ^{2 to} 50 kg / cm ² · G. The adjustment of the molecular weight in each step is generally performed by a molecular weight regulator (for example, hydrogen). However, in the case of controlling the molecular weight by the hydrogen concentration, if the hydrogen concentration in the previous stage is higher than that in the latter stage, it is necessary to provide a hydrogen purge process between both stages.

The reactor used in the polymerization step can be appropriately used as long as it is one usually used in the art. For example, a stirred tank reactor, a fluidized bed reactor, or a circulation reactor can be used. The polymerization operation can be performed in any of a continuous system, a semi-batch system, and a batch system. When carrying out multistage polymerization, the catalyst components (A), (B) and (C) are fed at the start of the polymerization, but the (B) and (C) components are separately fed. In the subsequent polymerization stage, if a plurality of polymerization reactors are used, they can be fed into the subsequent polymerization reactor.

As an example of the multi-stage polymerization method, Japanese Patent Laid-Open No. 3-1
2409 and JP-A-3-62807 can be mentioned. For example, the process at the step of polymerizing a high molecular weight component, the intrinsic viscosity _{[eta] H} is the set to 20 to 80 wt% of the production rate _{R H} of polypropylene from 1.5 to 5.5, to polymerize the low molecular weight component , The intrinsic viscosity [η] _L was 0.
4 to 2.5 for polypropylene production rate _{R L} twenty to eight
0% by weight. The intrinsic viscosity [η] _W of the final polymer is ([η] _H × _RH + [η] _L × R _L ) between the intrinsic viscosity and the polymerization ratio of each component in the two steps selected from the above range. ) / 100 = [η] _W ... (1), and further satisfies the following relationship: 1 ≦ ([η] _H − [η] _L ) / _RH ≦ 10 (2) This is a multi-stage polymerization method in which the xylene-soluble component _{XY of} polypropylene obtained in the step and the intrinsic viscosity [η] satisfy _XY ≦ −0.3 × [η] +3.0 (3). At this time, the production order of each polypropylene produced in the two steps is arbitrary, but it is preferable to polymerize using two or more polymerization vessels arranged in series.

Alternatively, in the step of polymerizing the high molecular weight component, the production ratio R ₁ of polypropylene having an intrinsic viscosity [η] ₁ of 3 or more is set to 10 to 50% by weight, and the intermediate molecular weight component is polymerized. The intrinsic viscosity [η] ₂ is 1 to 3
Polypropylene production rate _{R 2} and 10-70 wt%, In the step of polymerizing a low molecular weight component, the intrinsic viscosity _{[eta] 3} is a production ratio _{R 3} of polypropylene 0.2 to 1.0 10 -80% by weight. The intrinsic viscosity [η] _W of the final polymer is ([η] ₁ × R ₁ + [η] ₂ × R ₂ ) between the intrinsic viscosity and the polymerization ratio of each component in the three steps selected from the above range. + [Η] ₃ × R ₃ ) / 100 = [η] _W (4), the intrinsic viscosity [η] _W is 1 to 4 and the polypropylene xylene obtained in each of the three steps is acceptable. It is a multi-stage polymerization method in which the soluble component _XY and the intrinsic viscosity [η] satisfy _XY ≦ −0.3 × [η] +3.0 (5). At this time, the production order of each polypropylene produced in the three steps is arbitrary, but it is preferable to perform the polymerization using three or more polymerization vessels arranged in series.

[0076]

EXAMPLES The present invention will be shown below with reference to examples, but the present invention is not limited to these examples.

The properties of the polymers in Examples and Comparative Examples were measured by the following methods.

MFR: ASTMD-1238 Melt index according to condition E Intrinsic viscosity [η]: Measured in ortho-dichlorobenzene at 140 ° C. There is the following formula between the intrinsic viscosity [η] and the viscosity average molecular weight Mv. [Η] = 1.88 × 10 ⁻⁴ × Mv ^0.725 xylene solubles (X _Y ): 4 g of the sample was added to 200 m of xylene.
After dissolving in 1 l, it is left for 1 hour in a thermostat at 25 ° C.
The precipitated polypropylene is filtered and the filtrate is collected. After most of the xylene in the filtrate is evaporated, the xylene-soluble matter is recovered by further vacuum drying, and the xylene-soluble matter is obtained as a percentage based on the weight of the original sample. Crystallization temperature (Tc): measured by DSC. Flexural rigidity: According to JIS-K7203. Transparency (haze): According to JIS-K7105. The measured physical properties were obtained by adding known additives such as an oxidizing agent to the obtained polymer particles, melt-granulating them with a 25 mm extruder, and molding them with a Toshiba IS-100E injection molding machine. Evaluated.

Reference Example 1 [Preparation of catalyst component (A)] 2 l of an oak equipped with a stirrer
Metal magnesium powder 12g (0.49
mol), iodine 0.6 g, 2-ethylhexanol 319.1 g (2.45 mol) and titanium tetrabutoxide 168.0 g (0.49 mol),
198.3 g of tri-i-propoxyaluminum (0.
97 mol), and then 1 liter of decane, and then 90
The temperature was raised to ° C, and the mixture was stirred for 1 hour under a nitrogen seal while removing generated hydrogen gas. Subsequently, the temperature was raised to 140 ° C. and the reaction was carried out for 2 hours to obtain a uniform solution containing magnesium and titanium (Mg—Ti solution).

Mg-Ti was added to a flask having an internal volume of 500 ml.
After adding 0.048 mol of Mg in the solution and quenching to 0 ° C.,
i-Butyl aluminum dichloride 14.7 g (0.
A solution obtained by diluting (095 mol) to 50% with hexane was added over 2 hours. After adding all, the temperature was raised to 70 ° C. over 2 hours to obtain a slurry containing a white solid product, which was washed with hexane separated by filtration.

A total of a solution prepared by diluting 52 g (0.48 mol) of titanium tetrachloride with 52 g of chlorobenzene was added to the slurry containing the white solid product thus obtained, and then 4.9 g (0.019 mol) of diisobutyl phthalate was added. And reacted at 100 ° C. for 3 hours. The solid portion was collected by filtering the product, and titanium tetrachloride (52 g) was collected again.
A solution prepared by diluting (0.48 mol) with 52 g of chlorobenzene was added, and the mixture was stirred at 100 ° C. for 2 hours. Hexane was added to this product, and washing operation was sufficiently performed until no liberated titanium compound was detected to obtain a slurry of the catalyst component (A) suspended in hexane. The supernatant liquid was removed, the product was dried under a nitrogen atmosphere, and elemental analysis revealed that Ti was 3.0.
% By weight.

Reference Example 2 [Preliminary Polymerization of Catalyst Component (A)] A magnetic stirrer autoclave made of stainless steel and having an internal volume of 5 l was sufficiently replaced with nitrogen to obtain by the method of Reference Example 1 above. Catalyst component (A)
52 g, 326 mmol of triethylaluminum as the organometallic compound (B), 81.4 mmol of diphenyldimethoxysilane as the electron donating compound (C) were sequentially added, and 3 l of hexane was added. Then, sorbitan distearate was added so that the content would be 1400 ppm with respect to the total contents.

The autoclave internal pressure was set to 0.1 kg / cm ^2.
In G, after adjusting the internal temperature to 20 ° C., stirring was started and
While maintaining the temperature at 52 ° C, 52 g of liquid propylene was supplied over 20 minutes and stirred for 30 minutes.

Subsequently, the solid content was separated by filtration and sufficiently washed with hexane to obtain a slurry of the prepolymerized catalyst component suspended in hexane. The yield after removal of the supernatant and drying under a nitrogen atmosphere was 104 g. Therefore, 1 g of propylene was polymerized per 1 g of the catalyst component (A).

Example 1 The inside of a stainless steel electromagnetic stirring type autoclave having an internal volume of 5 l was sufficiently replaced with nitrogen, and 1.44 mmol of triethylaluminum was used as the component (B) and diphenyldimethoxysilane was used as the component (C). 0.72 mmol and 0.018 of the catalyst component (A) obtained in Reference Example 1 in terms of Ti
mmol sequentially added, and autoclave internal pressure 0.1 k
After adjusting to g / cm ² G, 0.02 kg / cm ^{2 of} hydrogen was added, and after stirring (600 rpm) was started, the temperature was adjusted to 80 ° C. and 1.6 kg of liquid propylene was added. 28 at the same temperature
Polymerize propylene for minutes.

After stirring and depressurization, 0.60 g of p-t-butylbenzoic acid was added, and the autoclave internal pressure was adjusted to 0.1 kg /
After adjusting to cm ² G, hydrogen was added at 4.0 kg / cm ² , and stirring (600 rpm) was started, and then the temperature was adjusted to 80 ° C., and 1.6 kg of liquid propylene was added. Propylene was polymerized for 26 minutes at the same temperature.

After completion of the polymerization reaction, stirring was stopped, and at the same time unreacted propylene in the system was discharged to recover the produced polymer.

As a result, the amount of the produced polymer was 1094 g. The activity per 1 g of the catalyst component (A) is 38100 g /
Corresponds to g.

MFR of this polymer 3.45 g / 10 minutes,
The intrinsic viscosity [η] was 1.85. Further, when estimated from the polymerization conditions, the intrinsic viscosity [η] of the polymer obtained in the first step was 3.0, the intrinsic viscosity [η] of the polymer obtained in the second step was 0.7, and Since the intrinsic viscosity [η] of the coalescence is 1.85, it is estimated that the production ratio in the first stage and the second stage is 50/50.

The bulk density of this polymer was 0.48, and the xylene solubles (X _Y ) was 1.3%. The results are shown in Table 1.

Further, Ir was added to this polymer as an additive.
Each of -1010, If-168, and calcium stearate was added in an amount of 1000 ppm, granulated with a 25 mm single-screw extruder, molded with a Toshiba IS-100E injection molding machine, and evaluated for physical properties. The results are shown in Table 3.

Comparative Example 1 The inside of an electromagnetic stirring type autoclave made of stainless steel having an internal volume of 5 l was sufficiently replaced with nitrogen, 1.44 mmol of triethylaluminum was used as the component (B), and diphenyldimethoxysilane was used as the component (C). 0.72 mmol and 0.018 of the catalyst component (A) obtained in Reference Example 1 in terms of Ti
mmol addition, the autoclave internal pressure is 0.1 kg / c
After adjusting to m ² G, hydrogen was added at 0.02 kg / cm ² , and after stirring (600 rpm) was started, the temperature was adjusted to 80 ° C. and 1.6 kg of liquid propylene was added. Propylene was polymerized at the same temperature for 30 minutes.

After the stirring was stopped and the pressure was released, the internal pressure of the autoclave was adjusted to 0.1 kg / cm ² G and hydrogen was 4.0 kg / c.
After adding m ² and starting stirring (600 rpm), 80 ° C.
As a result, 1.6 kg of liquid propylene was added. Propylene was polymerized for 11 minutes at the same temperature.

After the completion of the polymerization reaction, the stirring was stopped, and at the same time unreacted propylene in the system was discharged to recover the produced polymer.

As a result, the amount of the produced polymer was 1,136 g. The activity per gram of catalyst component (A) is 39300 g /
Corresponds to g.

The MFR of this polymer was 3.59 g / 10.
The intrinsic viscosity [η] was 1.85. Further, when estimated from the polymerization conditions, the intrinsic viscosity [η] of the polymer obtained in the first step was 3.0, the intrinsic viscosity [η] of the polymer obtained in the second step was 0.7, and Since the intrinsic viscosity [η] of the coalescence is 1.85, it is estimated that the production ratio in the first stage and the second stage is 50/50. The results are shown in Table 1.

The same additives as in Example 1 were blended with this polymer, which was granulated with a 25 mm extruder to measure the physical properties. The results are shown in Table 3.

Examples 2 to 6 Polymerization was carried out in the same manner as in Example 1 except that the kind and addition amount of the benzoic acid compound used were changed as shown in Table 1.
The results are shown in Tables 1 and 3.

Examples 7 and 8 Polymerization was carried out in the same manner as in Example 1 except that the kind of benzoic acid compound was changed to benzoic anhydride as shown in Table 1. The results are shown in Tables 1 and 3.

Example 9 The inside of an electromagnetic stirring type autoclave made of stainless steel having an internal volume of 5 l was sufficiently replaced with nitrogen, and 1.44 mmol of triethylaluminum as the component (B) and diphenyldimethoxysilane as the component (C). 0.72 mmol and 0.018 of the catalyst component (A) obtained in Reference Example 1 in terms of Ti
mmol sequentially added, and autoclave internal pressure 0.1 k
After adjusting to g / cm ² G, 0.02 kg / cm ^{2 of} hydrogen was added, and after stirring (600 rpm) was started, the temperature was adjusted to 80 ° C. and 1.6 kg of liquid propylene was added. 29 at the same temperature
Polymerize propylene for minutes.

After the stirring was stopped and the pressure was released, pt-butylbenzoic acid (0.60 g) and triethylaluminum (0.004 mmol) as component (B) were added to adjust the autoclave internal pressure to 0.1 kg / cm ² G. And hydrogen 4.0 kg / c
After adding m ² and starting stirring (600 rpm), 80 ° C.
As a result, 1.6 kg of liquid propylene was added. Propylene was polymerized for 13 minutes at the same temperature.

After the completion of the polymerization reaction, the stirring was stopped and at the same time unreacted propylene in the system was discharged to recover the produced polymer.

As a result, the amount of the produced polymer was 1070 g. The activity per 1 g of catalyst component (A) is 37,200 g /
Corresponds to g.

MFR of this polymer 3.48 g / 10 minutes,
The intrinsic viscosity [η] was 1.83. Further, when estimated from the polymerization conditions, the intrinsic viscosity [η] of the polymer obtained in the first step was 3.0, the intrinsic viscosity [η] of the polymer obtained in the second step was 0.7, and Since the intrinsic viscosity [η] of the coalescence is 1.83, it is estimated that the production ratio in the first stage and the second stage is 50/50.

The bulk density of this polymer was 0.48, and the xylene-soluble component (X _Y ) was 1.3%. The results are shown in Table 1.

Further, Ir-1010, I was added to this polymer.
f-168, calcium stearate 100 each
0 ppm was added, and the mixture was granulated with a 25 mm single-screw extruder, molded with a Toshiba IS-100E injection molding machine, and evaluated for physical properties. The results are shown in Table 3.

Example 10 As the component (C), di-i-butyldimethoxysilane.
Polymerization was carried out in the same manner as in Example 9 except that the amount was changed to 72 mmol. The results are shown in Tables 1 and 3.

Example 11 0.72 m of phenyldimethoxysilane as the component (C)
Polymerization was carried out in the same manner as in Example 9 except that the mol, the type of the benzoic acid compound, and the addition amount were changed as shown in Table 1. The results are shown in Tables 1 and 3.

Examples 12 and 13 Polymerization was carried out in the same manner as in Example 9 except that the kind of benzoic acid compound was changed to benzoic anhydride as shown in Table 1. The results are shown in Tables 1 and 3.

Example 14 A stainless steel electromagnetic stirring type autoclave having an internal volume of 5 l was sufficiently replaced with nitrogen, and 0.878 mmol of triethylaluminum was used as the component (B) and diphenyldimethoxysilane was used as the component (C). 0.438 mmol and the prepolymerized catalyst component (A) obtained in Reference Example 2 were added to Ti.
Add 0.012 mmol in order, add autoclave
Adjust the internal pressure to 0.1 kg / cm ² G and add hydrogen to 0.1
After kg / cm ^{2 was} added and stirring (600 rpm) was started, the temperature was adjusted to 80 ° C. and 1.6 kg of liquid propylene was added. After polymerizing at the same temperature for 10 minutes, 0.60 g of p-t-butylbenzoic acid was added. Then, the polymerization was continued for 140 minutes.

After the completion of the polymerization reaction, stirring was stopped and unreacted propylene in the system was discharged at the same time to collect the produced polymer.

As a result, the amount of the produced polymer was 1,100 g. The activity per 1 g of the catalyst component (A) is 57300 g /
Corresponds to g.

The MFR of this polymer was 2.5 g / 10 minutes,
The bulk density is 0.48, and the xylene-soluble component (X _Y ) is 1.1.
%Met. The results are shown in Table 2.

The same additives as in Example 1 were blended with this polymer, and the mixture was granulated with a 25 mm extruder to measure the physical properties. The results are shown in Table 3.

Examples 15 and 16 Polymerization was carried out in the same manner as in Example 14 except that the benzoic acid compound and benzoic anhydride shown in Table 2 were used. The results are shown in Tables 2 and 3.

Comparative Example 2 Polymerization was carried out in the same manner as in Example 14, except that pt-butylbenzoic acid was not used. The results are shown in Table 2 and Table 3.
It was shown to.

Comparative Example 3 Using the catalyst component (A) obtained in Reference Example 1, p-t-butylbenzoic acid was added and polymerized before the initiation of polymerization. As a result, the activity was very poor. The results are shown in Table 2.

Example 17 A magnetic stirrer type autoclave made of stainless steel having an internal volume of 5 l was sufficiently replaced with nitrogen, and 1.44 mmol of triethylaluminum was used as the component (B) and diphenyldimethoxysilane was used as the component (C). 0.72 mmol and the prepolymerized catalyst component (A) obtained in Reference Example 1 were sequentially added in 0.018 mmol in terms of Ti, the autoclave internal pressure was adjusted to 0.1 kg / cm ² G, and the mixture was stirred. (600 rp
After starting m), the temperature was raised to 80 ° C. and 1.6 kg of liquid propylene was added. Polymerization was carried out for 18 minutes at the same temperature. After the stirring was stopped and the pressure was released, pt-butylbenzoic acid was added to 0.6
0 g, triethylaluminum 0.0 as component (B)
04 mmol was added and the autoclave internal pressure was adjusted to 0.1 kg.
/ Cm ² G, add 0.2 kg / cm ^{2 of} hydrogen,
After starting stirring (600 rpm), the temperature was raised to 80 ° C., and 1.6 kg of liquid propylene was added. After polymerizing propylene for 13 minutes at the same temperature, stirring was stopped and the pressure was released. Again, the autoclave internal pressure is 0.1 kg / cm ² G
To 4.0 kg / cm ^{2, and} stirred (600
(rpm) was started, and then 80 ° C., 1.6 kg of liquid propylene was added, and propylene was polymerized at the same temperature for 23 minutes.

After the completion of the polymerization reaction, the stirring was stopped, and at the same time unreacted propylene in the system was discharged to recover the produced polymer. As a result, the amount of the produced polymer was 1,150 g. The activity per gram of catalyst component (A) corresponds to 40,000 g / g.

The MFR of this polymer was 4.35 g / 10.
The intrinsic viscosity [η] was 1.73. Further, when estimated from the polymerization conditions, the intrinsic viscosity [η] of the polymer obtained in the first step was 4.0 and the intrinsic viscosity [η] of the polymer obtained in the second step was 1.53 and The obtained polymer has an intrinsic viscosity [η] of 0.7, and the final polymer has an intrinsic viscosity [η] of 1.7.
Since it is 3, the production ratio of each stage 1, 2, 3 is 20
It is estimated to be / 43/37.

The bulk density of this polymer was 0.48, and the xylene-soluble component (X _Y ) was 1.4%. Moreover, Tc by DSC shows 130.8 ° C., and the flexural modulus is 18800 k.
The g / cm ² and haze were 60%.

[0122]

[Table 1]

[0123]

[Table 2]

[0124]

[Table 3]

[0125]

EFFECT OF THE INVENTION By using the method of the present invention, polypropylene having excellent rigidity and transparency and good processability can be obtained as compared with ordinary polypropylene.

[Brief description of drawings]

FIG. 1 is a flowchart for preparing a catalyst according to the present invention.

Claims (4)

[Claims] 1. A catalyst component comprising (A) a magnesium compound and a titanium compound as essential components, and (B) as a component, Ia, IIa, IIb of the periodic table,
In polymerizing propylene in the presence of a catalyst comprising at least one selected from organometallic compounds of Group IIIb and IVb metals and an electron-donating compound as the component (C), at least 0.1 g per 1 g of the catalyst component (A). After polymerizing 1 g of ethylene and / or α-olefin,
The following general formula (1) A benzoic acid compound represented by
_{1 to} R ₅ represent hydrogen, an alkyl group having 1 to 8 carbon atoms, an alkoxyl group having 1 to 8 carbon atoms, a halogen group, an amino group, a nitro group or a phenyl group), and the final polymer 10 obtained
A method for producing polypropylene, which comprises adding 0.001 to 1 part by weight to 0 part by weight and continuing the polymerization of propylene. 2. A catalyst component comprising (A) a magnesium compound and a titanium compound as essential components, and (B) as a component, Ia, IIa, IIb of the periodic table,
When polymerizing propylene in the presence of a catalyst comprising at least one selected from organometallic compounds of Group IIIb and IVb metals and an electron-donating compound as component (C), at least 0. After polymerizing 1 g of ethylene and / or α-olefin, the compound of the general formula (2) A benzoic anhydride represented by the formula (provided that the substituent of the compound, R
_{6 to} R _{15 each} represent hydrogen, an alkyl group having 1 to 8 carbon atoms, an alkoxyl group having 1 to 8 carbon atoms, a halogen group, an amino group, a nitro group, or a phenyl group).
A method for producing polypropylene, which comprises adding 0.001 to 1 part by weight to 00 parts by weight and continuing the polymerization of propylene. 3. A catalyst component containing (A) a magnesium compound and a titanium compound as essential components, and (B) as a component, Ia, IIa, IIb of the periodic table,
When polymerizing propylene in the presence of a catalyst comprising at least one selected from organometallic compounds of Group IIIb and IVb metals and an electron-donating compound as component (C), at least 0. After polymerizing 1 g of ethylene and / or α-olefin, the compound of the general formula (1) A benzoic acid compound represented by
_{1 to} R ₅ represent hydrogen, an alkyl group having 1 to 8 carbon atoms, an alkoxyl group having 1 to 8 carbon atoms, a halogen group, an amino group, a nitro group or a phenyl group), and the final polymer 10 obtained
A method for producing polypropylene, which comprises adding 0.001 to 1 part by weight to 0 part by weight, further adding the component (B), and continuing the polymerization of propylene. 4. A catalyst component comprising (A) a magnesium compound and a titanium compound as essential components, and (B) as components Ia, IIa, IIb of the periodic table,
When polymerizing propylene in the presence of a catalyst comprising at least one selected from organometallic compounds of Group IIIb and IVb metals and an electron-donating compound as component (C), at least 0. After polymerizing 1 g of ethylene and / or α-olefin, the compound of the general formula (2) A benzoic anhydride represented by the formula (provided that the substituent of the compound, R
_{6 to} R _{15 each} represent hydrogen, an alkyl group having 1 to 8 carbon atoms, an alkoxyl group having 1 to 8 carbon atoms, a halogen group, an amino group, a nitro group, or a phenyl group).
A method for producing polypropylene, which comprises adding 0.001 to 1 part by weight to 00 parts by weight, further adding the component (B), and continuing the polymerization of propylene.