JPH0788406B2 - Method for producing propylene random copolymer - Google Patents

Description

TECHNICAL FIELD The present invention relates to a method for producing a propylene-based random copolymer from propylene, ethylene and α-olefin having 4 to 10 carbon atoms.

More specifically, the present invention is excellent in heat sealability, heat sealability, transparency, and blocking resistance from propylene, ethylene, and α-olefin having 4 to 10 carbon atoms, has a small hydrocarbon-soluble content, and has a composition. The present invention relates to a method for producing a propylene-based random copolymer having a narrow distribution.

[Prior Art] Polypropylene has been used for a wide range of applications because of its excellent physical properties. For example, it is widely used in the field of packaging films, but in order to improve heat sealability at low temperatures in this type of application, ethylene is usually copolymerized in an amount of about 1 to 5% by weight, and propylene / ethylene copolymer It is generally provided as a united body. The polypropylene film modified as described above has the advantage that it has better transparency and scratch resistance than the low-density polyethylene film that is also used as a packaging film, but it is still inferior in heat sealing at low temperatures. There is. There is a method to further increase the copolymerization amount of ethylene in order to further improve the heat-sealing property, but in this case, the production rate of the soluble copolymer having no utility value is increased, and the yield of the target copolymer is increased. There is a disadvantage that Moreover, in the slurry polymerization, the slurry properties during the polymerization may be deteriorated and the polymerization may be difficult.

In order to avoid such disadvantages, a method of copolymerizing ethylene and α-olefin having 4 or more carbon atoms into propylene using a conventional titanium trichloride catalyst is disclosed in JP-A-49-35.
No. 487, JP-A-51-79195, JP-A-52-16588 and the like. According to these proposals, it can be said that the production ratio of the solvent-soluble polymer is reduced as compared with the case where the binary copolymerization of propylene and ethylene is performed.
Compared to the case of carrying out homopolymerization of propylene, the production ratio of the solvent-soluble polymer is still large, and this tendency becomes even greater as the copolymerization amount of ethylene and / or α-olefin at C ₄ or higher increases.

The present inventors have prepared a carrier-supported catalyst formed from a specific solid titanium catalyst component, an organometallic compound catalyst component and an electron donor catalyst component by copolymerizing propylene, ethylene and α-olefins having 4 or more carbon atoms. In comparison with the case where the titanium trichloride-based catalyst in the above proposal is used, the soluble polymer can be further reduced, and the yield of the target copolymer and the catalytic efficiency are remarkably excellent. Therefore, it was proposed in JP-A-54-26891. Although a remarkable improvement was observed by using the catalyst specifically disclosed in this publication, when it was attempted to produce a copolymer having a considerably high ethylene content, slurry properties were deteriorated due to porridge-like polymer formation. Therefore, it is difficult to continue the polymerization, and the solid polymer cannot be obtained in a sufficiently high yield. If the ethylene content cannot be increased to obtain a copolymer having a low melting point, the only method is to increase the content of α-olefin having 4 or more carbon atoms, but the effect of lowering the melting point is to reduce the melting point of the α-olefin. Since it is smaller and the rate of copolymerization is slower, it cannot be said that a method of increasing the content of the α-olefin more than necessary is a good idea.

Further, the inventors of the present invention disclosed in JP-A-59-47210 a copolymer of propylene, ethylene and α-olefin having 4 or more carbon atoms, which is suitable for use in a film having excellent heat-sealing property, as an inconvenient soluble copolymer. We proposed a method that can obtain high yield and high yield while reducing the by-product.
However, the copolymer obtained by this method is not necessarily sufficient in heat-sealing property, heat-sealing property, transparency and blocking resistance, and the amount of hydrocarbon-soluble components is not small enough.

[Problems to be Solved by the Invention] Therefore, the present invention is excellent in heat sealability, heat sealability, transparency, and blocking resistance from propylene, ethylene and α-olefin having 4 to 10 carbon atoms, and carbonization. It is an object of the present invention to provide a method for producing a propylene-based random copolymer having a low hydrogen-soluble content.

[Means for Solving the Problems] According to the present invention, the above-mentioned object includes (A) magnesium, titanium, a halogen and an electron donor as essential components and has an average particle size of about 5 to about.
A catalyst formed from a highly active and highly stereoregular titanium catalyst component having a geometric standard deviation value of less than 2.1 at 300 μm, (B) an organoaluminum metal compound catalyst component, and (C) an electron donor catalyst component. And in the presence of a catalyst containing an electron donor (C) in the range of 0.5 to 30 moles per gram atom of titanium of the titanium catalyst component (A), 20 per gram of the titanium catalyst component (A). In the presence of an α-olefin prepolymerization catalyst obtained by prepolymerizing α-olefin having 2 to 20 carbon atoms in the range of 1 to 1000 g.
10 α-olefins under the condition that they form a gas phase
By copolymerizing at a polymerization temperature of 30 to 130 ° C., the repeating unit (a) derived from propylene is 86 to 97 mol%, and the repeating unit (b) derived from ethylene is
0.5 to 6 mol% and the repeating unit (c) derived from the α-olefin is in the range of 2 to 13 mol%, and
The c / (b + c) molar ratio is in the range of 0.3 to 0.9, and the melting point [Tm] measured by a differential scanning calorimeter is 115 to 1
In the range of 40 ° C, the soluble amount [W ₁ wt%] in n-decane at 25 ° C is 0.03 (165-Tm) ≤ W ₁ ≤ 0.20 (165-Tm) [where Tm is The melting point of the coalescence is shown].

The copolymer of propylene, ethylene and α-olefin having 4 to 10 carbon atoms obtained by the method of the present invention is excellent in heat-sealing property, heat-sealing property, transparency and blocking resistance and has a hydrocarbon-soluble content. It has few features and a narrow composition distribution.

The present invention will be described in detail below.

First, the catalyst used in the present invention will be described.

The highly active, highly stereoregular solid titanium catalyst component (A) used in the present invention contains magnesium, titanium, halogen and an electron donor as essential components, and the magnesium / titanium (atomic ratio) is 1 or more. Large and preferably 2
To 50, particularly preferably 6 to 30, halogen / titanium (atomic ratio) is preferably 4 to 100, particularly preferably 6 to 40, electron donor / titanium (molar ratio) is preferably 0.1 to 10, particularly preferably. It is in the range of 0.2 to 6. Its specific surface area is preferably 3 m ² / g or more,
More preferably from about 40 m ² / g or more, more preferably 100 m ² /
g to 800 m ² / g. Usually, titanium compounds are not eliminated by simple means such as hexane washing at room temperature.
Further, in addition to the above essential components, other elements, metals, functional groups, etc. may be contained. In addition, Teflon, polyethylene,
It may be supported on an organic or inorganic carrier such as polypropylene, silica, or aluminium.

The solid titanium catalyst component (A) has an average particle size of 5 to 30.
0 μm, preferably 10 to 150 μm, particularly preferably
15 to 100 μm with a geometric standard deviation of 2.1
Less, preferably 1.9 or less, more preferably 1.7 or less.

Here, the particle size distribution of the titanium catalyst component particles can be measured by a light transmission method. Specifically, dilute the catalyst components in an inert solvent such as decalin to a concentration of around 7 wt / vol%, put them in a cell for measurement, shine light on the cell, and pass the liquid in a sedimented state with particles. The particle size distribution is measured by continuously measuring the light intensity. The standard deviation σg is obtained from the lognormal distribution function based on this particle size distribution. More specifically, the average particle size (D ₅₀ ) and the small particle size make the particle size (D ₅₀ ) 16%.
Σg is determined as the ratio of the _{16) (D 50 / D 16} ).

The solid titanium catalyst component (A) has the ability to produce a highly stereoregular polymer at a high catalyst high rate, for example, the ability to produce it under the same conditions, for example, under the same conditions. When propylene homopolymerization is carried out under the following conditions, isotacticity (boiling n-heptane insoluble matter) is 92% or more, especially 96% or more polypropylene is 3,000 per 1 mmol of Ti.
It has the ability to produce g or more, particularly 5,000 g or more, and more preferably 10,000 g or more. And, preferably, it has a shape such as a true sphere, an elliptic sphere, or a granule.

By using a titanium catalyst component satisfying these requirements, a copolymer having a high ethylene content can be produced with good operability and in a high yield.

The titanium catalyst component (A) satisfying all the above conditions is prepared by forming a magnesium compound having an average particle size and particle size distribution, more preferably a shape in the above range, and then preparing the catalyst. A method of performing, or a method of contacting a liquid magnesium compound and a liquid titanium compound to form a solid catalyst so as to have the above-mentioned particle properties, and other forms of the above-mentioned carrier Mg compound, Ti compound And a method of supporting an electron donor or granulating the fine powder catalyst into the above-mentioned preferable shape. Such a method is disclosed in, for example, JP-A-55-135102, JP-A-55-135103,
56-811, 56-67311, Japanese Patent Application 56-181019,
61-21109 and the like.

A few examples of these methods are briefly described.

(1) A magnesium compound / electron donor complex having an average particle size of 5 to 300 μm and a geometric standard deviation σg of particle size distribution of less than 2.1 is used as a reaction aid such as an electron donor and / or an organoaluminum compound or a halogen-containing silicon compound. It is either pretreated with the agent or, without pretreatment, with a titanium halide compound which is in the liquid phase under the reaction conditions, preferably titanium tetrachloride.

(2) A solid having an average particle size of 5 to 300 μm and a geometric standard deviation σg of less than 2.1 obtained by reacting a liquid material of a magnesium compound having no reducing ability with a liquid titanium compound in the presence of an electron donor. Precipitate the ingredients. If necessary, a liquid titanium compound, preferably titanium tetrachloride, or it is reacted with an electron donor.

Particularly, in the present invention, in the case of using the magnesium compound or the electron donor complex precipitated from the liquid as a spherical solid in the method of (1), or (2)
Good results can be obtained when the precipitation of the solid component by the method described in (1) is carried out under the condition that a spherical solid is precipitated.

As the magnesium compound used for the preparation of the titanium catalyst component, magnesium oxide, magnesium hydroxide, hydrotalcite, magnesium carboxylate, alkoxy magnesium, allyloxy magnesium, alkoxy magnesium halide, allyloxy magnesium halide, magnesium dihalide, Examples thereof include organomagnesium compounds, reaction products of organomagnesium compounds with electron donors, halosilanes, alkoxysilanes, silanols, aluminum compounds and the like. The organoaluminum compound that may be used in the preparation of the titanium catalyst component may be selected from the organoaluminum compounds that can be used in the olefin polymerization described below. Furthermore, examples of the halogen-containing silicon compound that may be used for the preparation of the titanium catalyst component include tetrahalogenated silicon, alkoxyhalogenated silicon, alkylhalogenated silicon, and halopolysiloxane.

Examples of titanium compounds used for preparing the titanium catalyst component include titanium halides, alkoxy titanium halides,
Examples thereof include allyloxytitanium halides, alkoxytitaniums, and allyloxytitanium, and titanium tetrahalide, particularly titanium tetrachloride, is preferable.

Examples of electron donors that can be used to prepare the titanium catalyst component include alcohols, phenols, ketones, aldehydes, carboxylic acids, esters of organic or inorganic acids, ethers, acid amides, and alkoxysilanes of acid anhydrides. Oxygen electron donors, nitrogen-containing electron donors such as ammonia, amines, nitriles, and isocyanates can be used.

More specifically, it has 1 to 18 carbon atoms such as methanol, ethanol, propanol, pentanol, hexanol, octanol, dodecanol, octadecyl alcohol, benzyl alcohol, phenylethyl alcohol, cumyl alcohol and isopropylbenzyl alcohol.
Alcohols of 6 to 20 carbon atoms which may have a lower alkyl group such as phenol, cresol, xylenol, ethylphenol, propylphenol, nonylphenol, cumylphenol and naphthol; acetone, methylethylketone, methylisobutylketone C3 to C15 ketones such as acetophenone, benzophenone and benzophenone; acetaldehyde, propionaldehyde, octylamdehyde, benzaldehyde,
Aldehydes having 2 to 15 carbon atoms such as tolualdehyde and naphthaldehyde; methyl formate, methyl acetate, ethyl acetate, vinyl acetate, propyl acetate, octyl acetate, cyclohexyl acetate, ethyl propionate, ethyl butyrate, ethyl valerate, chloroacetic acid. Methyl, ethyl dichloroacetate,
Methyl methacrylate, ethyl crotonate, cyclohexanecarboxylate, methyl benzoate, ethyl benzoate, propyl benzoate, butyl benzoate, octyl benzoate, cyclohexyl benzoate, phenyl benzoate, benzyl benzoate, methyl toluate, toluyl Ethyl acid, amyl toluate, ethyl ethyl benzoate, methyl anisate, ethyl anisate, ethyl ethoxybenzoate,
Dibutyl malonate, isopropyl diethyl malonate, n
-Diethyl butyl malonate, diethyl phenylmalonate, diethyl 2-allylmalonate, diethyl diisobutyl malonate, diethyl di-n-butylmalonate, di-n-butyl succinate, diethyl methylsuccinate, dibutyl ethylsuccinate, dimethyl maleate, maleic acid Dibutyl, monooctyl maleate, dioctyl maleate, dibutyl butyl maleate, diethyl butyl maleate, diisooctyl fumarate, diethyl itaconate, di-n-butyl itaconate, dimethyl citracone, diethyl 1,2-cyclohexanedicarboxylate, Di-2-ethylhexyl 1,2-cyclohexanedicarboxylate, dimethyl phthalate, monoisobutyl phthalate, diethyl phthalate, ethyl n-butyl phthalate, di-n-propyl phthalate, n-butyl phthalate, isobutyl phthalate, lid Di n-heptyl phthalate, di 2-ethylhexyl phthalate, di n- octyl,
Dyneopentyl phthalate, benzyl butyl phthalate, diphenyl phthalate, diiso-butyl naphthalenedicarboxylate, di2-ethylhexyl sebacate, γ-butyrolactone, δ-valerolactone, coumarin, phthalide, carbon number 2 to 30 such as ethylene carbonate. Organic acid esters of C2 to C15 such as acetyl chloride, benzoyl chloride, toluyl chloride, and anisyl chloride
C2 to C20 ethers such as methyl ether, ethyl ether, isopropyl ether, butyl ether, isoamyl ether, tetrahydrofuran, anisole and diphenyl ether; acids such as acetic acid amide, benzoic acid amide and toluic acid amide Amides; methylamine, ethylamine, diethylamine, tributylamine, piperidine, tribenzylamine, aniline, pyridine, picoline, tetramethylmethylenediamine, tetramethylethylenediamine, and other amines; acetonitrile, benzonitrile, tolunitrile, and other nitriles; Organophosphorus compounds having a P—O—C bond such as trimethyl phosphate and triethyl phosphite; alkoxysilanes such as ethyl silicate and diphenyldimethoxysilane; and the like It can be mentioned. Two or more kinds of these electron donors can be used.

The electron donors that are preferably contained in the titanium catalyst component (A) include organic acid or inorganic acid esters, alkoxy (aryloxy) silane compounds, ethers, ketones, tertiary amines, acid halides, acid anhydrides. Organic acid esters and alkoxy (aryloxy) silane compounds are particularly preferable because they do not have active hydrogen, and among these, esters of aromatic monocarboxylic acids and alcohols having 1 to 8 carbon atoms, malonic acid, substituted malonic acid, substituted amber. Esters of dicarboxylic acids such as acid, maleic acid, substituted maleic acid, 1,2-cyclohexanedicarboxylic acid and phthalic acid with alcohols having 2 or more carbon atoms are particularly preferable. Of course, these electron donors do not necessarily have to be used as raw materials when preparing the titanium catalyst, but may be used as other compounds that can be converted into these electron donors and converted into these electron donors during the catalyst preparation process.

The titanium catalyst component obtained by the various methods as exemplified above can be purified by sufficiently washing with a liquid inert hydrocarbon after the reaction. As the inert liquid hydrocarbon used for this purpose, n-pentane, isopentane, n-pentane,
Hexane, isohexane, n-heptane, n-octane, isooctane, n-decane, n-dodecane, kerosene,
Aliphatic hydrocarbons such as liquid paraffin; Alicyclic hydrocarbons such as cyclopentane, methylcyclopentane, cyclohexane, methylcyclohexane; Aromatic hydrocarbons such as benzene, toluene, xylene, cymene; Chlorobenzene, dichloroethane Such halogenated hydrocarbons or mixtures thereof can be exemplified.

The preferred organometallic compound catalyst component (B) used in the present invention is an organoaluminum compound, and a compound having at least one Al-carbon bond in the molecule can be used. For example, (i) the general formula R ¹ mAl (OR ² ) nHPXq (where R
¹ and R ² are usually 1 to 15 carbon atoms, preferably 1
The hydrocarbon groups containing 4 to 4 may be the same or different. X is halogen, m is 0 <m ≦ 3, n is 0 ≦ n <
3, p is a number 0 ≦ p <3, q is a number 0 ≦ q <3, and m + n + p + q = 3), (ii) a general formula M ¹ AlR ¹ ₄ (wherein M ¹ is L
i, Na, K, and R ¹ is the same as the above)
Examples thereof include complex alkylated products of group metals and aluminum.

Examples of the organoaluminum compound belonging to (i) above include the following. General formula R ¹ mAl (OR ² )
_3-m (where R ¹ and R ² are the same as above. M is preferably
1.5 ≦ m ≦ 3). General formula R ¹ mAlX _3-m (where R ¹
Is the same as above. X is halogen, m is preferably 0 <m <
3 is a) the general formula R ¹ MAlH _3-m (wherein R ¹ is as .m said is preferably 2 ≦ m <3), the general formula R ¹ mAl
(OR ² ) nXq (where R ¹ and R ² are the same as before. X is halogen, 0 <m ≦ 3, 0 ≦ n <3, 0 ≦ q <3, and m + n +
For example, those represented by q = 3) can be exemplified.

In the aluminum compound belonging to (i), more specifically, trialkyl aluminum such as triethyl aluminum and tributyl aluminum, trialkenyl aluminum such as triisoprenyl aluminum, diethyl aluminum ethoxide, dialkyl aluminum alkoxide such as dibutyl aluminum butoxide, In addition to alkylaluminum sesquialkoxides such as ethylaluminum sesquiethoxide and butylaluminum sesquibutoxide, partially aluminumized alkylaluminum having an average composition represented by R ¹ _2.5 Al (OR ² ) _0.5 , diethylaluminum chloride Dialkyl aluminum halides such as dibutyl aluminum chloride, diethyl aluminum bromide, ethyl aluminum Partially halogenated, such as alkylaluminum sesquihalides such as musesquichloride, butylaluminum sesquichloride, ethylaluminum sesquibromide, alkylaluminum dihalides such as ethylaluminum dichloride, propylaluminium dichloride, butylaluminium dibromide, etc. Partially hydrogenated alkyl aluminum such as alkyl aluminum, diethyl aluminum hydride, dialkyl aluminum hydride such as dibutyl aluminum hydride, ethyl aluminum dihydride, alkyl aluminum dihydride such as propyl aluminum dihydride, ethyl aluminum ethoxy chloride, butyl aluminum Butoxycyclolide, ethyl aluminum ethoxy bromide, etc. To a alkoxylated and halogenated alkylaluminum. Further, the compound similar to (i) may be an organoaluminum compound in which two or more aluminums are bound via an oxygen atom or a nitrogen atom. Examples of such compounds include (C ₂ H ₅ ) ₂ AlOAl (C ₂ H ₅ ) ₂ and (C ₄ H ₉ ) ₂ AlOAl
(C ₄ H ₉ ) ₂ , Can be exemplified. Examples of the compound belonging to (ii) above include LiAl (C ₂ H ₅ ) ₄ and LiAl (C ₇ H ₁₅ ) ₄ . Among these, it is particularly preferable to use trialkylaluminum or a mixture of trialkylaluminum and alkylaluminum halide or aluminum halide.

Examples of the electron donor used as the catalyst component (C) are amines, amides, ethers, ketones, nitriles, phosphines, stibines, arsines, phosphoramides, esters, thioethers, thioesters. And acid anhydrides, acid halides, aldehydes, alcoholates, alkoxy (aryloxy) silanes, organic acids, and amides and salts of metals belonging to Groups 1 to 4 of the periodic table. . Salts can also be formed in situ by the reaction of an organic acid with an organometallic compound used as catalyst component (B).

Specific examples thereof include titanium catalyst component (A)
The electron donor contained in the above can be selected from those exemplified above. Good results are obtained with organic acid esters, alkoxy (aryloxy) silane compounds, ethers, ketones, acid anhydrides, amines and the like. Particularly when the electron donor in the titanium catalyst component (A) is a monocarboxylic acid ester, the electron donor as the component (C) is preferably an alkyl ester of an aromatic carboxylic acid.

Further, when the electron donor in the titanium catalyst component (A) is an ester of a dicarboxylic acid and an alcohol having 2 or more carbon atoms as exemplified above as preferable ones, the general formula RnSi
(OR ¹ ) _4-n (In the formula, R and R ¹ are hydrocarbon groups, and an alkoxy (aryloxy) silane compound represented by 0 ≦ n <4) or an amine having large steric hindrance may be used as the component (C). preferable. Specific examples of the alkoxy (aryloxy) silane compound include trimethylmethoxysilane, trimethylethoxysilane, dimethyldimethoxysilane,
Dimethyldiethoxysilane, diisopropyldimethoxysilane, t-butylmethyldimethoxysilane, t-butylmethyldiethoxysilane, t-amylmethyldiethoxysilane, diphenyldimethoxysilane, phenylmethyldimethoxysilane, diphenyldiethoxysilane, bis o-tolyldimethoxysilane, bis-m-tolyldimethoxysilane, bis-p-tolyldimethoxysilane, bis-p
-Tolyldiethoxysilane, bisethylphenyldimethoxysilane, dicyclohexyldimethoxysilane, cyclohexylmethyldimethoxysilane, cyclohexylmethyldiethoxysilane, ethyltrimethoxysilane, ethyltriethoxysilane, vinyltrimethoxysilane,
Methyltrimethoxysilane, n-propyltriethoxysilane, decyltrimethoxysilane, decyltriethoxysilane, phenyltrimethoxysilane, γ-chloropropyltrimethoxysilane, methyltriethoxysilane, ethyltriethoxysilane, vinyltriethoxysilane , T-butyltriethoxysilane, n-butyltriethoxysilane, isobutyltriethoxysilane, phenyltriethoxysilane, γ-aminopropyltriethoxysilane, chlorotriethoxysilane, ethyltriisopropoxysilane, vinyltributoxysilane, Cyclohexyltrimethoxysilane, cyclohexyltrimethoxysilane, 2-norbornanetrimethoxysilane,
2-norbornanetriethoxysilane, 2-norbornanemethyldimethoxysilane, ethyl silicate, butyl silicate, trimethylphenoxysilane, methyltriallyloxy silane, vinyltris (β-methoxyethoxysilane), vinyltriacetoxysilane , Dimethyltetraethoxydisiloxane, etc., among which ethyltriethoxysilane, n-propyltriethoxysilane, t-butyltriethoxysilane, vinyltriethoxysilane, phenyltriethoxysilane, vinyltributoxysilane, diphenyldimethoxysilane, Phenylmethyldimethoxysilane, bis-p-tolyldimethoxysilane, p-tolylmethyldimethoxysilane, dicyclohexyldimethoxysilane, cyclohexylmethyldimethoxysilane, 2-nor Bornanetriethoxysilane, 2
-Norbornanemethyldimethoxysilane, diphenyldiethoxysilane, ethyl silicate and the like are preferable.

The amine having a large steric hindrance is 2,2,6,6-
Tetramethylpiperidine, 2,5,5-tetramethylpyrrolidine, derivatives thereof, tetramethylmethylenediamine and the like are particularly preferable. Among these compounds, an alkoxy (aryloxy) silane compound is particularly preferable as the electron donor used as the catalyst component (C).

In the prepolymerization in the present invention, it is preferable to use a catalyst system in which the electron donor catalyst component (C) coexists in addition to the catalyst component (A) and the organometallic compound (B).
In this case, it is preferable to use 0.5 to 30 mol, preferably 0.7 to 10 mol, and more preferably 1 to 5 mol of the electron donor catalyst component (C) per gram atom of titanium of the titanium catalyst component (A). is there. In the prepolymerization, α-olefin having 2 to 10 carbon atoms is prepolymerized in an inert hydrocarbon solvent or with a liquid monomer as a solvent or without using a solvent. Prepolymerization is particularly preferred.

The amount of polymerization in the prepolymerization is 20 to 1000 g, preferably 30 to 500 g, and more preferably 40 per 1 g of the titanium catalyst component.
To 200g. It is not preferable to increase the amount of this prepolymerization more than necessary because it hinders the improvement of the heat-sealing property.

As the inert hydrocarbon solvent used in the prepolymerization, propane, butane, n-pentane, isopentane, n-hexane, isohexane, n-heptane, n-octane,
Aliphatic hydrocarbons such as isooctane, n-decane, n-dodecane and kerosene, alicyclic hydrocarbons such as cyclopentane, methylcyclopentane, cyclohexane and methylcyclohexane, aromatic hydrocarbons such as benzene, toluene and xylene. , Methylene chloride, ethyl chloride,
Examples thereof include halogenated hydrocarbons such as ethylene chloride and chlorobenzene. Among them, aliphatic hydrocarbons, particularly aliphatic hydrocarbons having 4 to 10 carbon atoms are preferable.

When an inert solvent or a liquid monomer is used in the prepolymerization, the titanium catalyst component (A) is converted to titanium atom in an amount of 0.001 to 500 mmol, particularly 0.005 per solvent.
It is preferable that the organoaluminum compound (B) has an Al / Ti (atomic ratio) of 0.5 to 50 mmol.
It is preferably used in a ratio of 0, preferably 1.0 to 50, more preferably 2.0 to 20.

Examples of α-olefins used for prepolymerization include ethylene, propylene, 1-butene, 1-pentene, 4-methyl-1-pentene, 3-methyl-1-pentene, 1-heptene, 1-octene, 1- Those having 10 or less carbon atoms such as decene are preferable, those having 3 to 6 carbon atoms are more preferable, and propylene is particularly preferable. These α-olefins may be homopolymerized, or may be copolymerized with two or more kinds as long as a crystalline polymer is produced.

The polymerization temperature in the prepolymerization varies depending on the type of the α-olefin and the inert hydrocarbon solvent used and cannot be specified unconditionally, but is generally −40 to 80 ° C., preferably −
The temperature is 20 to 40 ° C, more preferably about -10 to 30 ° C. For example, when α-olefin is propylene, it is -40
To 70 ° C, -40 to 40 ° C for 1-butene, 4-
In the case of methyl-1-pentene or 3-methyl-1-pentene, about -40 to 70 ° C is suitable. Hydrogen can coexist in the preliminary polymerization.

In the present invention, propylene, ethylene and the number of carbon atoms are 4 using the catalyst obtained by prepolymerizing α-olefin.
Random copolymerization of 10 to 10 α-olefins is performed.
1,000 to 100,000 g, preferably 2,000 to 50,000 g, and more preferably 3,000 to 30, per gram of the titanium catalyst component (A) of the catalyst obtained by prepolymerizing α-olefin.
000 g of propylene, ethylene and 4 to 4 carbon atoms
A vapor phase mixture of 10 α-olefins is copolymerized.

In addition, propylene, ethylene and the number of carbon atoms is 4 to
In carrying out random copolymerization of 10 α-olefins using a catalyst formed from the titanium catalyst component (A), the organometallic compound catalyst component (B), and the electron donor catalyst component (C), the titanium catalyst It is preferable to use the organometallic compound catalyst component (B) in an amount of 1 to 1000 mol, preferably 5 to 500 mol, particularly preferably 10 to 100 mol, per gram atom of titanium in the component (A). The amount of the electron donor catalyst component (C) is 0.01 to 0.01 per gram atom of the metal element in the organometallic compound catalyst component (B).
100 mol, preferably 0.2 to 10 mol, particularly preferably
Preference is given to using 0.3 to 2 mol.

In the present invention, it is necessary to copolymerize the monomers in the gas phase. Further, it is preferable that a part or all of these α-olefins be gasified outside the polymerization system and then supplied to the polymerization system, and it is particularly preferable to gasify the whole amount and then supply the polymerization system.

The polymerization temperature is 50 to 130 ° C under the condition that the monomer is in the gas phase,
Preferably 65 to 120 ° C., more preferably 75 to 110
Perform at ℃. The polymerization pressure is not particularly limited as long as the monomer is in the gas phase at the use temperature, but is 1 to 50 kg / cm ² , preferably 2 to 30 kg / cm ² , and more preferably 5 to 20 kg / cm ² . Further, an inert gas such as methane, ethane, propane, butane and nitrogen which forms a gas state in the polymerization system may be appropriately supplied.

In the present invention, by employing the above-mentioned polymerization conditions, the repeating unit (a) derived from propylene is 86 to 97 mol%, preferably 86 to 96 mol%, more preferably 88 to 90 mol%, and particularly preferably 90 to 95 mol%,
Repeating unit (b) derived from ethylene is 0.5 to 6
Mol%, preferably 1 to 5 mol%, more preferably
1.5 to 4 mol% and 2 to 13 mol% of the repeating unit (c) derived from the α-olefin, preferably 2.
5 to 13 mol%, more preferably 3 to 11 mol%,
Particularly preferably, a propylene-based random copolymer in the range of 4 to 8 mol% is produced. The molar ratio c / (b + c) of the repeating unit (b) derived from ethylene and the repeating unit (c) derived from the α-olefin is 0.3.
To 0.9, preferably 0.4 to 0.8, more preferably
It is in the range of 0.5 to 0.8.

The intrinsic viscosity [η] of the propylene random copolymer obtained by the method of the present invention measured in decalin at 135 ° C. is in the range of 0.5 to 6 dl / g, preferably 1 to 5 dl / g.

The melting point of the propylene random copolymer obtained by the method of the present invention measured by a differential scanning calorimeter [hereinafter, may be abbreviated as DSC melting point] is 115 to 140.
℃, preferably 115 to 133 ℃, particularly preferably 120
To 130 ° C. Here, the DSC melting point is 25 to 2 at a temperature rising rate of 10 ° C / min for a press sheet having a thickness of 0.1 mm after a lapse of 20 hours after molding using a Perkin Elmer DSC-II type.
It was measured up to 00 ° C, and the maximum endothermic peak was taken as Tm.

Furthermore, the crystallinity of the propylene random copolymer obtained by the method of the present invention is in the range of 30 to 60%, preferably 40 to 60%, as measured by the X-ray diffraction method. The crystallinity was determined by X-ray diffraction measurement of a press sheet having a thickness of 1.5 mm 20 hours after the formation.

Further, the soluble amount [W ₁ % by weight] in the n-decane solvent at 25 ° C. of the propylene random copolymer obtained by the method of the present invention is 0.03 (in terms of the melting point Tm of the copolymer). _{165-Tm) ≦ W 1 ≦} 0.20 (165-Tm) preferably, 0.03 (165-Tm) ≦ W 1 ≦ 0.15 (165-Tm) and particularly preferably, 0.04 (165-Tm) ≦ W 1 ≦ 0.13 (165 -Tm) Particularly preferably, 0.05 (165-Tm) ≤ W ₁ ≤ 0.11 (165-Tm) (where Tm is the numerical value of the DSC melting point of the copolymer, and represents a value excluding dimension). ) Is satisfied. The amount of the copolymer soluble in n-decane at 25 ° C was measured by the following method. That is, with stirring blade 1
In a flask containing 5 g of the copolymer sample, 0.3 g of 2,6-diter.
Add t-butyl-4-methylphenol and 50 ml of n-decane and dissolve in an oil bath at 130 ° C. After the solution is dissolved, it is naturally cooled at room temperature for about 3 hours and then cooled in a water bath at 25 ° C. for 8 hours or more. An n-decane solution containing the precipitated copolymer and dissolved polymer was over-separated with a G-4 glass filter, and the solution was dried at 10 mmHg at 150 ° C until a constant weight was obtained. The soluble content of the copolymer was calculated and determined as a percentage with respect to the weight of the sample copolymer.

The content (B ₁ mol%) (F) of α-olefin having 4 to 20 carbon atoms in the n-decane-soluble component of the propylene random copolymer obtained by the method of the present invention is represented by the following formula 0.5B. ₂ ≤ B ₁ ≤ 5.0 B ₂ preferably 0.6 B ₂ ≤ B ₁ ≤ 3.0 B ₂ particularly preferably 0.7 B ₂ ≤ B ₁ ≤ 1.5 B ₂ (wherein B ₂ is 4 to 4 carbon atoms in the random copolymer). 20 α
-Olefin content (in mol%)).

The number of carbon atoms used in the method of the present invention is 4 to
As α-olefin of 10, 1-butene, 1-pentene, 1-hexene, 4-methyl-1-pentene, 1-heptene, 1-octene, 1-decene are preferable, and the one having 4 to 8 carbon atoms. Preferred are those having 1-butene. The copolymerization is carried out so that the amount thereof is usually 50 times or more, preferably 100 times or more, more preferably 500 times or more of the preliminary polymerization amount.

The copolymer obtained according to the present invention is excellent in heat-sealing property, heat-sealing property, transparency, and blocking property, and has a low hydrocarbon-soluble content. Therefore, a film, particularly a film for packaging such as a shrinkable film, for example, a film for food packaging, is used. Suitable for use. Of course, it is also suitable for applications such as hollow bottles.

[Examples] The present invention will be specifically described below with reference to Examples.

For the copolymer obtained by measuring the blocking resistance of the film and the complete heat-sealing temperature, the method for determining the blocking resistance and the complete heat-sealing temperature of the film will be described below.

Making a film A sheet of aluminum with a thickness of 0.1 mm
Tell sheet (made by Toray Industries, Inc., trade name Lumirror) and
Polyimide with a thickness of 50μ, with the center cut into a 15cm × 15cm square
Resin (manufactured by Deyupon, product name Kapton) sheets in this order
Spread 0.8 g of sample in the center (the cut out part)
placed. Then Lumirror Aluminum plate, press plate
Further stack in this order (Fig. 1).

Put the sample sandwiched between the above press plates in a hot press at 200 ° C, preheat for about 5 minutes, and pressurize (20 kg / cm ² G) depressurization operation to remove bubbles in the sample. Repeat times. Then, finally, the pressure is raised to 150 kg / cm ² G, and pressure heating is performed for 5 minutes. After depressurizing, remove the press plate from the press machine,
Transferred to another press machine with the crimping part kept at 30 ℃ 100kg / cm ²
After pressure cooling for 4 minutes, the pressure is released and the sample is taken out. Among the obtained films, a film having a uniform thickness of 50 to 70 μm is used as the following measuring film.

Anti-blocking test Two pieces of film cut into 6 x 10 cm are stacked and sandwiched between two pieces of paper of uniform thickness, and then a glass plate of about 5 mm thickness is further sandwiched under a load of 7 kg and placed in a 60 ° C constant temperature bath.
Leave for days (aging). After taking the film out of the constant temperature bath and cooling it to room temperature, part of one end of this double-layered film was peeled off, a Teflon rod was inserted here, and then the end of the peeled film was clipped and the tensile tester was used. Secure to the upper jack. At the same time, the Teflon rod was fixed to the lower chuck via the fixing bracket (see Fig. 2). The stress when two films are separated via a Teflon rod fixed by pulling the upper chuck at a speed of 10 cm / min is measured using a tensile tester. The obtained stress value is divided by the width of the film used (6 cm) to obtain the film blocking value (g / cm), which is a measure of the blocking resistance.

Measurement of heat seal strength The film prepared by the above-mentioned method is placed in a thermostatic chamber at 50 ° C.
Leave for days (aging). When aging, put paper on both sides of the film so that the films do not touch each other. Cut the above-aged film into 15mm-width strips, stack the two pieces, and then
Heat seal with two Teflon films with a thickness of 0.1 mm sandwiched between them. Heat sealing is performed by keeping the lower temperature of the heat plate of the heat sealer constant at 70 ° C and changing only the temperature of the upper part of the heat plate in steps of 5 ° C. Heat-sealing pressure is 2 kg / cm ² , heat-sealing time is 1 second, and seal width is 5
mm (hence the sealing area is 15 mm x 5 mm).

The heat-sealing strength is determined by performing a peeling test on the peel strength of the film heat-sealed at each of the above heat-sealing temperatures at a pulling speed of 30 cm / min (see FIG. 3).

The peel strength at each heat-sealing temperature in steps of 5 ° C. is obtained by the method described above, and a plot of the heat-sealing temperature vs. the peel strength is connected by a curve. Based on this curve, the heat seal temperature at which the peel strength is 800 g / 15 cm is defined as the complete heat seal temperature (see Fig. 4).

Example 1 [Preparation of solid titanium catalyst component with high activity and high stereoregularity] 714 g of anhydrous magnesium chloride, decane 3.7 and 2-ethylhexyl alcohol 3.5 were heated to react at 130 ° C. for 2 hours to form a uniform solution, and then this solution was prepared. Phthalic anhydride is added therein, and the mixture is further stirred and mixed at 130 ° C. for 1 hour to dissolve phthalic anhydride in the homogeneous solution. The homogeneous solution thus obtained is cooled to room temperature and then added dropwise into titanium tetrachloride kept at -20 ° C over 1 hour. After the completion of charging, the temperature of this mixed solution was raised to 110 ° C over 4 hours, and when it reached 110 ° C, diisobutylphthalate 0.4 was added.
Is added and the mixture is maintained at the same temperature for 2 hours with stirring. After the completion of the reaction for 2 hours, the solid part was collected by heating, and the solid part was resuspended in 28 TiCl ₄ , and then 110 ° C. again.
The reaction is heated for 2 hours. After the completion of the reaction, the solid portion is again collected by heating, and the solid portion is thoroughly washed with 110 ° C. deca and hexane until no free titanium compound is detected in the washing liquid. The titanium catalyst component synthesized by the above manufacturing method was dried with a dryer. The composition of the titanium catalyst component thus obtained was 2.3% by weight of titanium, 58.0% by weight of chlorine, 18.0% by weight of magnesium and 14.0% by weight of diisobutylphthalate.

The titanium catalyst component was a granular catalyst having an average particle size of 18μ and a geometric standard deviation (σg) of particle size distribution of 1.2.

[Preliminary Polymerization] Hexane 10 was mixed with 100 mmol of triethylaluminum and 20 mmol of diphenyldimethoxysilane. Titanium catalyst (dry product) synthesized by the previous synthesis method was added to the mixed solution (10 mmol in terms of titanium atom).
And reslurried for 2 hours. Next, propylene was supplied to carry out 3 Hr prepolymerization so that 50 g per 1 g of the titanium catalyst component.

The polymerization temperature was controlled at 0-8 ° C. After completion of the prepolymerization, the mixture was washed 6 times with hexane, then diluted with hexane so that the concentration of the titanium catalyst component would be 2 mmol / Ti atom, and stored in a container equipped with a stirrer.

[Polymerization] A polymerization reaction was performed using a fluidized bed type polymerization reactor having a diameter of 340 mm and a reaction volume of 40. In the fluidized bed type polymerization reactor, the catalyst was supplied from a catalyst supply nozzle at a ratio of 0.6 mmol Ti / Hr and N ₂
Gas 100Nl / Hr and propane (liquid) 2.5 / H were continuously sprayed as a mixture as a mixture, and ethylene propylene as a raw material olefin, mixed olefin consisting of 1-butene and H ₂ gas as a molecular weight control agent. The continuous gas phase polymerization reaction was carried out while continuously supplying. Of the raw olefin, 1-butene was vaporized by a vaporizer. The composition of the raw material gas at the time of supply is as follows, and C ₄ ⁼ / C ₃ ⁼ (mol) 0.0977 C ₂ ⁼ / C ₃ ⁼ (〃) 0.0233 H ₂ / C ₃ ⁼ (〃) 0.0016 N ₂ / C ₃ ⁼ (〃) 0.0388 The supply rate of propylene was 5160 Nl / H.

The temperature at the time of the gas phase polymerization reaction is 90 ° C., the pressure is 8.0 kg / cm ² G, the gas superficial velocity is 40 cm / s, and the produced amount of ethylene, propylene, and 1-butene random copolymer obtained is 40 cm / s. 5kg /
The supply amount of the prepolymerized catalyst was controlled so that H was obtained.

Triethylaluminum was prepared in advance with hexane to a concentration of 200 mmol / H, and it was continuously fed at 15 to 20 mmol / H. On the other hand, diphenyldimethoxysilane, which was previously prepared with hexane to a concentration of 200 mmol / 15,
It was continuously fed at -20 mmol / Hr. Table 1 shows other polymerization conditions and the results of basic physical properties and film physical properties of the polymer obtained by the above polymerization.

Examples 2 to 4 Preliminary polymerization was carried out in the same manner as in Example 1 using the titanium catalyst component prepared in the same manner as in Example 1.
Then, random copolymerization was carried out by the gas phase polymerization method under the conditions shown in Table 1. Table 1 shows the basic physical properties and film physical properties of the produced copolymer.

Only in Example 5, the prepolymerization conditions were changed such that the amount of propylene supplied was 96 g per 1 g of the titanium catalyst component and the prepolymerization time was 5 Hr.

Comparative Example 1 The prepolymerization amount was changed to 3 g per 1 g of the catalyst, and the copolymerization conditions were changed to those shown in Table 3. Table 3 shows the basic physical properties and film physical properties of the obtained copolymer.

EFFECTS OF THE INVENTION The present invention has excellent heat-sealing properties, heat-sealing properties, transparency, and blocking properties, and has a low hydrocarbon-soluble content of propylene, ethylene, and α-olefin propylene having 4 carbon atoms and 10 carbon atoms. Provide a random copolymer.

[Brief description of drawings]

FIG. 1 shows a schematic cross-sectional view of the film preparation method used in the test, FIG. 2 shows a schematic view of the measuring method of the film blocking value, and FIG. 3 shows a schematic view of the heat-sealing strength measuring method. , FIG. 4 shows the relationship between heat seal temperature and peel strength. FIG. 5 is a flow chart showing the steps for producing the catalyst used in the present invention.

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Norio Kashiwa 1-2-9 Murokimachi, Iwakuni City, Yamaguchi Prefecture

Claims (1)

[Claims] 1. A highly active and highly stereoscopic product comprising (A) magnesium, titanium, a halogen and an electron donor as essential components and having an average particle size of about 5 to about 300 μm and a geometric standard deviation of the particle size distribution of less than 2.1. A catalyst formed from a regular titanium catalyst component, (B) an organoaluminum compound catalyst component, and (C) an electron donor catalyst component, wherein the titanium catalyst component (A) contains 0.5 to 0.5 per gram atom of titanium. Prepolymerization of α-olefin having 2 to 20 carbon atoms in the range of 20 to 1000 g per gram of the titanium catalyst component (A) in the presence of a catalyst containing the electron donor (C) in the range of 30 mol. In the presence of the α-olefin prepolymerization catalyst thus obtained, propylene, ethylene and α-olefin having 4 to 10 carbon atoms are added at a weight of 30 to 130 ° C. under the condition that they form a gas phase. By copolymerizing at temperatures, repeating units derived from propylene (a) is 86
To 97 mol%, repeating units derived from ethylene (b)
Is 0.5 to 6 mol% and the repeating unit (c) derived from the α-olefin is in the range of 2 to 13 mol%, and the c / (b + c) molar ratio is in the range of 0.3 to 0.9. The melting point [Tm] measured by a calorimeter is in the range of 115 to 140 ° C, and the soluble amount [W ₁ % by weight] in n-decane at 25 ° C is 0.03 (165-Tm) ≤ W ₁ ≤ 0.20 ( 165-Tm) [wherein Tm represents the melting point of the copolymer] to produce a propylene-based random copolymer.