JPH0686507B2 - Process for producing propylene block copolymer - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial application] The present invention relates to a method for producing a propylene-based block copolymer.

More specifically, the present invention is excellent in heat-sealing property, heat-sealing property, transparency, and anti-blocking property, has a small amount of hydrocarbon-soluble components, and is suitable for packaging films such as shrink films, especially food packaging films. It relates to the production of suitable propylene block copolymers.

[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 temperature in this kind of application, ethylene is usually copolymerized at about 1 to 5% by weight, and propylene / ethylene random copolymer is used. It is generally provided as a polymer. 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.
The heat sealability at low temperatures is inferior. There is a method to further increase the amount of ethylene copolymerized to further improve the heat-sealing property, but in this case, the production ratio of the soluble copolymer which has no utility value increases and the blocking resistance and transparency are deteriorated. There is a disadvantage that the yield of the target copolymer is reduced. 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-49-354.
87, JP-A-51-79195 and JP-A-52-16588. According to these proposals, it can be said that the production ratio of the solvent-soluble copolymer is reduced as compared with the case where the binary copolymerization of propylene and ethylene is performed.
Compared with the case of carrying out homopolymerization of propylene, the production ratio of the solvent-soluble copolymer is still large, and as the copolymerization amount of ethylene and / or α-olefin of C ₄ or more increases, the tendency becomes even larger. .

The present inventors have compared the titanium trichloride-based catalyst in the above proposal with a specific solid titanium catalyst component and an organometallic compound catalyst component in which the production ratio of a solvent-soluble copolymer is almost equal in propylene homopolymerization. When a carrier catalyst formed of a catalyst component of an electron donor and an electron donor catalyst is used for the copolymerization of propylene, ethylene and α-olefin having 4 or more carbon atoms, it is expected that the titanium trichloride-based catalyst in the above proposal is used. In addition, it was found that the soluble copolymer can be further reduced, and the yield of the target copolymer and the catalytic efficiency can be remarkably excellent.
It was proposed in JP-A-54-26891. Although a significant improvement was observed by using the catalyst specifically disclosed in this publication, when a copolymer having a considerably high ethylene content was to be produced, a porridge-like copolymer was formed. Due to the deterioration of the slurry properties due to the above, it is difficult to continue the polymerization, and some difficulties remain unless the solid polymer is 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,
Since the effect of lowering the melting point is smaller with α-olefin, and the rate of copolymerization is slower, it cannot be said that a method of increasing the content of α-olefin more than necessary is a good idea.

Further, the inventors of the present invention disclosed in JP-A-59-47210, propylene suitable for film use with excellent heat sealability,
A method has been proposed in which a copolymer of ethylene and α-olefin having 4 or more carbon atoms can be obtained in a high yield and a high yield while reducing the disadvantageous by-product of the soluble copolymer. However, the copolymer obtained by this method is not necessarily sufficient in heat-sealing property, heat-sealing property, transparency, and anti-blocking property, and the hydrocarbon-soluble content is not so small as to be sufficiently satisfied.

The propylene-based copolymer in the above-mentioned conventional technique is obtained by a random copolymer.

On the other hand, an α-olefin-based copolymer obtained by block copolymerization instead of a random copolymer is also known.

Japanese Unexamined Patent Publication (Kokai) No. 58-162620 discloses an α-olefin block copolymer excellent in heat sealability, transparency and blocking resistance obtained by block copolymerization of α-olefin. However, the olefin block copolymer does not have heat sealability, blocking resistance and heat seal aging resistance comparable to those of the polyolefin composition disclosed in JP-B-57-24375.

[Problems to be Solved by the Invention] Accordingly, the present invention is a propylene-based block copolymer which is excellent in heat-sealing property, transparency and blocking resistance and has a small amount of hydrocarbon-soluble matter, and is currently known. The propylene-based block copolymer, which has superior heat-sealing property, anti-blocking property, and heat-seal resistance over time, than the propylene-based random copolymer composition (blend product) has little or no loss of the copolymer. It is intended to be provided without accompanying.

[Means for Solving the Problems] According to the present invention, the above 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 20.
A highly active and highly stereoregular titanium catalyst component having a particle size distribution geometric standard deviation of less than 2.1 at 0 μ, (B) a catalyst component of an organometallic compound of a metal of Groups 1 to 3 of the periodic table, and (C) an electron An α-obtained by prepolymerizing α-olefin having 2 to 10 carbon atoms in the range of 1 to 2000 g per gram of the titanium catalyst component (A) in the presence of a catalyst formed from a donor catalyst component. In the presence of an olefin prepolymerization catalyst, propylene, ethylene and 4 to 20 carbon atoms are present.
And the step of copolymerizing α-olefin in the suspension polymerization step [a] using liquid propylene as a solvent, and then the liquid unreacted raw material in the polymerization reaction mixture obtained in the suspension polymerization step is flashed to be vaporized. Depending on the process, the number of repeating units (a) derived from propylene was 86.
To 97 mol%, 0.5 to 6 mol% of the repeating unit (b) derived from ethylene and 2 to 13 mol% of the repeating unit (c) derived from α-olefin having 4 to 20 carbon atoms. , The molar ratio c / (b + c) is
The flash step (b) for producing a propylene-based random copolymer in the range of 0.3 to 0.9, propylene and carbon in the presence of the propylene-based random copolymer and under the condition that the reaction system forms a gas phase. By repeating the copolymerization of α-olefin having 4 to 20 atoms, the repeating unit (d) derived from propylene becomes
Α- with 10 to 90 mol% and 4 to 20 carbon atoms
Repeating unit (e) derived from olefin is 10 to 90
The above object is achieved by a method for producing a propylene-based block copolymer, characterized in that a gas-phase polymerization step [c] for producing a low-crystalline propylene-based random copolymer in the range of mol% is combined. It

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. Further, it may be diluted with an organic or inorganic diluent.

The solid titanium catalyst component (A) has an average particle size of 1 to 20.
The particle size distribution has a geometric standard difference of less than 2.1, preferably 1.9 or less, and more preferably 1.7 or less, with 0 μm, preferably 3 to 100 μm, particularly preferably 6 to 50 μm.

Here, the particle size distribution of the titanium catalyst component particles can be measured by a light transmission method. Specifically, dilute the catalyst component in an inert solvent such as decalin to a concentration of about 0.01 to 0.5%, put it in a measurement cell, 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, Vg is calculated as the ratio (θ ₅₀ / θ ₁₆ ) of the average particle diameter (θ ₅₀ ) and the particle diameter (θ ₁₆ ) that is 16 wt% in view of the small particle diameter. The average particle diameter of the catalyst is shown by the weight average diameter.

The solid titanium catalyst component (A) has the ability to produce a highly stereoregular polymer with high catalytic efficiency. For example, when homopolymerization of propylene is carried out under the same conditions, the isotacticity (boiling point) n-heptane-insoluble matter) 92% or more, particularly 96% or more of polypropylene is 3,000 g or more, particularly 5,000 g or more, and more preferably 10,0 per 1 mmol of Ti.
It has the ability to manufacture over 00g. 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. It can be obtained by a method of performing, or a method of bringing a liquid magnesium compound and a liquid titanium compound into contact with each other to form a solid catalyst having the above-mentioned particle properties. In addition to this method, there is a method of supporting the Mg compound, the Ti compound and the electron donor on the above-mentioned carrier having a uniform shape, or a method of granulating the fine powder catalyst into the above-mentioned preferable shape. For example, JP-A Nos. 55-135102, 55-135103, and 56
-811, 56-67311, Japanese Patent Applications 56-181019, 61-2110
No. 9 is disclosed.

A few examples of these methods are briefly described.

(1) A magnesium compound / electron donor complex having an average particle size of 5 to 200μ and a geometric standard deviation σg 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 diameter of 5 to 200 μ 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 in the preparation of the titanium catalyst component include titanium halides, alkoxy titanium halides, allyloxy titanium halides, alkoxy titanium, allyloxy titanium, etc., among others, tetrahalogenated titanium, especially titanium tetrachloride. 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, methyl ethyl ketone, methyl isobutyl ketone, acetophenone, benzophenone and other ketones having 3 to 15 carbon atoms; acetaldehyde, propionaldehyde, octyl aldehyde, benzaldehyde, tolualdehyde, naphthaldehyde and the like having 2 to 15 carbon atoms
Aldehydes of methyl formate, methyl acetate, ethyl acetate, ethyl butyrate, propyl acetate, octyl acetate, cyclohexyl acetate, ethyl propionate, methyl acetate, ethyl valerate, methyl chloroacetate, ethyl dichloroacetate, methyl methacrylate, croton Acid ethyl, cyclohexanecarboxylate, methyl benzoate, ethyl benzoate,
Propyl benzoate, butyl benzoate, octyl benzoate, cyclohexyl benzoate, phenyl benzoate, benzyl benzoate, methyl toluate, ethyl toluate,
Amyl toluate, ethyl ethyl benzoate, methyl anisate, ethyl anisate, ethyl ethoxybenzoate, dibutyl malonate, diethyl isopropylmalonate, diethyl n-butylmalonate, diethyl phenylmalonate, 2
-Diethyl allyl malonate, diethyl diisobutyl malonate, diethyl di-n-butyl malonate, di-n-butyl succinate, diethyl methyl succinate, dibutyl ethyl succinate, dimethyl maleate, dibutyl maleate, monooctyl maleate, dioctyl maleate, Butyl maleic acid dibutyl, butyl maleic acid diethyl, fumarate di iso octyl, itaconic acid diethyl, itaconic acid di n
Butyl, dimethyl citracone, diethyl 1,2-cyclohexanedicarboxylate, di-2-ethylhexyl 1,2-cyclohexanedicarboxylate, dimethyl phthalate, mono isobutyl phthalate, diethyl phthalate, ethyl n-butyl phthalate, diphthalate n-propyl, n-butyl phthalate,
Isobutyl phthalate, Di-n-heptyl phthalate, Di-n-ethylhexyl phthalate, Di-n-octyl phthalate, Dineopentyl phthalate, Benzyl butyl phthalate, Diphenyl phthalate, Naphthalenedicarboxylic acid di-iso-butyl, Di-2-ethylhexyl sebacate , Γ-butyrolactone,
Organic acid esters having 2 to 30 carbon atoms such as δ-valerolactone, coumarin, phthalide and ethylene carbonate; Acid halides having 2 to 15 carbon atoms such as acetyl chloride, benzoyl chloride, toluic acid chloride and anisic acid chloride; methyl Ethers having 2 to 20 carbon atoms such as ether, ethyl ether, isopropyl ether, butyl ether, isoamyl ether, tetrahydrofuran, anisole, diphenyl ether; acid amides such as acetic acid amide, benzoic acid amide, toluic acid amide; methylamine, Ethylamine, diethylamine, tributylamine, piperidine, tribenzylamine, aniline,
Pyridine, picoline, tetramethylmethylenediamine,
Amines such as tetramethylethylenediamine; nitriles such as acetonitrile, benazonitrile, tolunitrile; organic phosphorus compounds having a P—O—C bond such as trimethyl phosphite and triethyl phosphite; ethyl silicate, diphenyldimethoxysilane, etc. Alkoxysilanes; and the like. 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, and 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.

After completion of the reaction, the titanium catalyst component obtained by the various methods as exemplified above can be purified by thoroughly washing with a liquid inert hydrocarbon. 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 _m Al (OR ² ) nHpXq (where R ¹
R ² and R ² are hydrocarbon groups usually containing 1 to 15, preferably 1 to 4 carbon atoms and 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 _m Al (OR ² ) _3-m (wherein R ¹ and R ² are the same as above. M is preferably 1.5 ≦ m
≦ 3). General formula R ¹ _m AlX _3-m (wherein R ¹ is as defined above, X is halogen, m is preferably 0 <m <3), general formula R ¹ _m AlH _3-m (where R ^{1 is} Is the same as described above, m is preferably 2 ≦ m <3), and the general formula R ¹ _m Al (OR ² ) nXq
(Here, R ¹ and R ² are the same as above. X is halogen, 0 <
m ≦ 3, 0 ≦ n <3, 0 ≦ q <3, and m + n + q = 3).

In the aluminum compound belonging to (i), more specifically, trialkylaluminum such as triethylaluminum and tributylaluminum, trialkenylaluminum such as triisoprenylaluminum, dialkylaluminum alkoxide such as diethylaluminum ethoxide and dibutylaluminum butoxide. In addition to alkylaluminum sesquialkoxides such as ethyl aluminum sesquiethoxide and butylaluminum sesquibutoxide, partially alkoxylated alkylaluminum having an average composition represented by R ¹ _2.5 Al (OR ² ) _0.5 , diethylaluminum Dialkyl aluminum halides such as chloride, dibutyl aluminum chloride, diethyl aluminum bromide, ethyl aluminum Partially halogenated alkylaluminums such as alkylaluminum sesquihalides such as sukichloride, butylaluminum sesquichloride, ethylaluminum sesquibromide, alkylaluminum dihalides such as ethylaluminum dichloride, propylaluminium dichloride, butylaluminum dibromide Partially hydrogenated alkyl aluminum such as 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 Parts such as ethyl aluminum ethoxy bromide It is alkoxylated and halogenated alkyl aluminum. 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 , (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 reaction with organic acids with the organometallic compounds 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.

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 a preferable example, the compound represented by the general formula RnSi (O 2
R ¹ ) _4-n (wherein 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 is preferably used as the component (C). . Specific examples of the alkoxy (aryloxy) silane compound include trimethylmethoxysilane, trimethylethoxysilane, dimethyldimethoxysilane, dimethyldiethoxysilane, diisopropyldimethoxysilane, t-butylmethyldimemethoxysilane, 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, iso-butyltriethoxysilane, phenyltriethoxysilane, γ-aminopropyltriethoxysilane, chlorotriethoxysilane, Ethyltriisopropoxysilane, vinyltributoxysilane, cyclohexyltrimethoxysilane, cyclohexyltriethoxysilane, 2-norbornanetrimethoxysilane,
2-norbornanetriethoxysilane, 2-norbornanemethyldimethoxysilane, ethyl silicate, butyl silicate, trimethylphenoxysilane, methyltriallyloxy silane, vinyltris (β-methoxyethoxysilane), vinyltriacetoxysilane , Dimethyltetraethoxydisiloxane, etc., and especially ethyltriethoxysilane, n-propyltriethoxysilane, t-butyltriethoxysilane, vinyltriethoxysilane, phenyltriethoxysilane, vinyltributoxysilane, diphenyldimethoxysilane. , Phenylmethyldimethoxysilane, bis-p-tolyldimethoxysilane, p-tolylmethyldimethoxysilane, dicyclohexyldimethoxysilane, cyclohexylmethyldimethoxysilane, 2-no Nebornanetriethoxysilane,
2-Norbornanemethyldimethoxysilane, diphenyldiethoxysilane, ethyl silicate and the like are preferable.

The amine having a large steric hindrance is 2,2,6,6-
Tetramethylpiperidine, 2,2,5,5-tetramethylpyrrolidine, derivatives thereof, tetramethylmethylenediamine and the like are particularly preferable. Among these compounds, the 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 that case, it is preferable to use 0.1 to 30 mol, preferably 0.5 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. 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, but in an inert hydrocarbon solvent or Prepolymerization in liquid monomer is particularly preferred.

The amount of polymerization in the prepolymerization is 1 to 2000 g, preferably 3 to 1000 g, and more preferably 10 per 1 g of the titanium catalyst component.
Or 500g. 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, iso-pentane, n-
Hexane, isohexane, n-heptane, n-octane, isooctane, n-decane, n-dodecane, aliphatic hydrocarbons such as kerosene, cyclopentane, methylcyclopentane, cyclohexane, alicyclic hydrocarbons such as methylcyclohexane, Examples thereof include aromatic hydrocarbons such as benzene, toluene and xylene, halogenated hydrocarbons such as methylene chloride, ethyl chloride, ethylene chloride and chlorobenzene. Among them, aliphatic hydrocarbons, particularly those having 4 to 4 carbon atoms can be mentioned. Ten aliphatic hydrocarbons are preferred.

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 0.1
It is preferably 005 to 100 mmol, and the organoaluminum compound (B) has an Al / Ti (atomic ratio) of 0.5 to
1000, preferably 1.0 to 200, more preferably 2.0
It is preferable to use it in a ratio such that it becomes 50 to 50.

Examples of α-olefin used in the prepolymerization include ethylene, propylene, 1-butene, 1-pentene, 4-methyl-1-pentene, 3-methyl-1-pentene, 1-heptene 1-octene and 1-decene. Those having 10 or less carbon atoms 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 α-olefin and the inert solvent used and cannot be specified unconditionally, but it is generally -40 to 80 ° C, preferably -20 to
The temperature is 40 ° C, more preferably about -10 to 30 ° C. For example, when α-olefin is propylene, it is -40 to 70
℃, in the case of 1-butene -40 to 40 ℃, 4-methyl-
-40 for 1-pentene and 3-methyl-1-pentene
Or about 70 ° C is suitable. Hydrogen can coexist in the preliminary polymerization.

In the suspension polymerization step [a] in the present invention, propylene, ethylene and α-olefin having 4 to 20 carbon atoms are copolymerized with the α-olefin prepolymerization product as a catalyst. As α-olefin having 4 to 20 carbon atoms, propylene, 1-butene, 1-pentene, 1-
Hexene, 4-methyl-1-pentene, 3-methyl-1
Examples include-pentene, 1-heptene, 1-octene, 1-decene, 1-dodecene, 1-tetradecene, 1-octadecene. Of these, α-olefins having 4 to 10 carbon atoms are preferable, and α-olefins having 4 to 6 carbon atoms are particularly preferable. In the suspension polymerization step of the present invention, propylene used as a copolymerization monomer is used as a reaction medium. In the suspension polymerization step [a], the catalyst component (A) is converted to titanium atom in an amount of about 0.0001 to about 1 millimole and the catalyst component (B) is converted to the metal atom in an amount of about 0.001 to about 1 mmol per liquid phase. The catalyst component (C) is selected from about 0.001 to about 100 mmol, and the metal atom in the catalyst component (B) is from about 1 to about 10 per 1 mol of titanium atom in the catalyst component (A).
The amount should be 00 mol, preferably about 1 to about 300 mol. The proportion of the catalyst component (C) used is usually 0.01 to 10 moles, and more preferably 1 to 10 moles, based on the total amount of metal atoms of Groups 1 to 3 of the periodic table of the catalyst component (B).
It is 0.1 to 5.0 mol, particularly preferably 0.2 to 2.0.

The polymerization temperature is from room temperature to about 90 ° C, preferably about 50 ° C to about 80 ° C.
℃ can be used. The polymerization pressure is not particularly limited, but the range of atmospheric pressure to about 50 kg / cm ² , preferably atmospheric pressure to 40 kg / cm ² , can be adopted.

During the polymerization, hydrogen can be used as a molecular weight regulator of the target copolymer.

In the flushing step [b] of the present invention, liquid unreacted raw material, that is, unreacted propylene and a carbon atom number of 4 to 20 are obtained from the suspension polymerization reaction product obtained in the suspension polymerization step [a]. The α-olefin is removed by flushing. 20 to 20 in the flash process
It is carried out at 0 ° C., preferably 40 to 150 ° C., more preferably 50 to 100 ° C. for 1 minute to 3 hours, preferably 5 minutes to 2 hours, more preferably 10 minutes to 1 hour.
The flushing step can be performed by an ordinary method.

In the method of the present invention, the crystalline propylene random copolymer obtained by the flash polymerization step [b] for the suspension polymerization step [a] has a repeating unit (propylene component) (a) derived from propylene of 86 to 97. Mol%, preferably 88 to 96 mol%, more preferably 89 to 95 mol%, and the repeating unit (ethylene component) (b) derived from ethylene is 0.5 to 6 mol%, preferably 1 to 5 mol%, more preferably Is 2 to 13 mol%, preferably 3 to 11 mol%, more preferably 1.5 to 4 mol% and the repeating unit (α-olefin component) (c) derived from α-olefin having 4 to 20 carbon atoms. Four
Crystalline propylene having a molar ratio c / (b + c) of 0.3 to 0.9, preferably 0.4 to 0.8, and more preferably 0.5 to 0.8 in the range of 1 to 9 mol%, particularly preferably 4 to 7 mol%. Form a random copolymer. In order to produce such a propylene-based random copolymer, although it may be slightly different depending on the polymerization conditions and the type of α-olefin, the supply ratio of the raw materials in the suspension polymerization step [a] is 70 to 98 mol% of propylene. , Preferably 75
To 95 mol%, more preferably 80 to 92 mol%, ethylene 0.1 to 5 mol%, preferably 0.2 to 4 mol%, more preferably 0.3 to 3 mol%, α-olefin 4 having 4 to 20 carbon atoms. To 40 mol%, preferably 8 to 30 mol%, more preferably 12 to 25 mol%.

In the method of the present invention, the intrinsic viscosity [η] of the crystalline propylene random copolymer obtained in the flash step [a] measured in decalin at 135 ° C. is 0.5 to 6 dl /
g, preferably in the range 1 to 5 dl / g. The intrinsic viscosity of the crystalline propylene-based random copolymer is determined by reducing the thickness of the heat-sealing layer of the polypropylene composite laminate in which the low-crystalline propylene-based random copolymer composition is laminated, and the heat-sealing of the composite laminate. The above range is preferable in terms of strength and heat sealable temperature by heat treatment.

The melting point [Tm] of the crystalline propylene random copolymer measured by a differential scanning calorimeter is 115 ° C to 145 ° C,
It is preferably in the range of 120 ° C to 140 ° C, more preferably 120 ° C to 135 ° C. From the heat sealing temperature of the polypropylene composite laminate in which the low crystalline propylene random copolymer composition is laminated, the heat seal strength, the blocking of the polypropylene composite laminate, the scratch resistance, the heat sealable temperature by heat treatment, and the like, The DSC melting point is preferably in the above range. Where the DSC melting point is 20
After a lapse of time, a press sheet having a thickness of 0.1 mm was measured at a temperature rising rate of 10 ° C / min from 0 to 200 ° C, and the maximum endothermic peak was defined as Tm.

The crystallinity of the crystalline propylene random copolymer measured by X-ray diffraction is 30 to 60%, preferably 35.
Or in the range of 55%. The crystallinity of the crystalline propylene-based random copolymer is the heat-sealing temperature, heat-sealing strength of the polypropylene composite laminate in which the low-crystalline propylene-based random copolymer composition is laminated, the heat-sealing strength of the polypropylene composite laminate. Blocking resistance, scratch resistance,
The above range is preferable from the heat sealing temperature by heat treatment. The crystallinity was determined by X-ray diffraction measurement of a 1.5 mm thick pressed sheet formed by pressing at 180 ° C. for 10 minutes and then at 25 ° C. for 10 minutes.

The soluble amount [W ₁ % by weight] of n-decane at 25 ° C. of the crystalline propylene random copolymer [I] has a general formula of 0.03 (165−) in relation to the melting point Tm of the copolymer. Tm) ≤ W ₁ ≤ 0.20 (165-Tm) preferably the general formula 0.03 (165-Tm) ≤ W ₁ ≤ 0.15 (165-Tm) (where Tm is the numerical value of the melting point of the copolymer) ,
It shows the value excluding the dimension). When the amount of the n-decane-soluble component is more than the above range, the blocking resistance of the polypropylene composite laminated molding in which the low crystalline propylene random copolymer composition is laminated is deteriorated.

Here, the crystalline propylene-based random copolymer of 25 ℃
The amount of soluble matter in the n-decane solvent in is measured and determined by the following method. That is, 5 g of the copolymer sample and 0.3 g of 2,6-ditert-dimethyl-
Add 4-methylphenol and 500 ml of n-decane and dissolve on a 140 ° C. oil bath. After dissolution, the mixture is naturally discharged for about 3 hours at room temperature and then cooled in a water bath at 25 ° C for 12 hours.
An n-decane solution containing the precipitated copolymer and dissolved polymer was overseparated with a G-4 glass filter, and the solution was adjusted to 10 mm.
It is dried with Hg at 150 ° C. to a constant weight, and the polymer dissolved in n-decane is collected. Measure its weight, 25 ℃
The soluble content of the copolymer in n-decane solvent was calculated and determined as a percentage with respect to the weight of the sample copolymer.

In the gas phase polymerization step [c] of the present invention, the propylene and the number of carbon atoms in the presence of the propylene random copolymer obtained in the flash step [b], preferably a powdery propylene random copolymer, Propylene and the α-olefin are copolymerized under conditions where 4 to 10 α-olefins form the gas phase. 100 to 100,000 g, preferably 500 to 50,000, per gram of the titanium catalyst component (A) of the catalyst obtained by prepolymerizing α-olefin.
g, more preferably 1,000 to 10,000 g of propylene and a gas phase mixture of 4 to 10 carbon atoms α-olefin are copolymerized. In the gas phase polymerization step, it is necessary to copolymerize the monomers in the gas phase. The reason is as follows.

In polymerization using a hydrocarbon solvent, the propylene / α-olefin random copolymer is easily eluted in the hydrocarbon solvent, and the heat-sealing property and heat-sealability of the resulting propylene-based block copolymer are sufficient. Not only can it not be increased, but the viscosity of the hydrocarbon solvent also rises, making it difficult to carry out a stable polymerization operation.

As α-olefin having 4 to 20 carbon atoms, 1
-Butene, 1-pentene, 1-hexene, 4-methyl-
1-pentene, 1-heptene, 1-octene, 1-decene, 1-dodecene, 1-tetradecene, 1-octadecene and the like having 18 or less carbon atoms are preferable, and those having 4 carbon atoms and 8 are particularly preferable. is there. The copolymerization is carried out so that the amount thereof is usually 100 times or more, preferably 500 times or more, more preferably 1000 times or more of the preliminary polymerization amount.

In the gas phase polymerization step, the repeating unit (propylene component) (d) derived from propylene is 10 to 90 mol%,
Preferably from 30 to 85 mol%, more preferably from 50 to
80 mol%, the repeating unit derived from the α-olefin (α-olefin component) (e) is 10 to 90 mol%, preferably 15 to 70 mol%, more preferably 20 to 50
A propylene / α-olefin random copolymer in the range of mol% is formed. The proportion of these propylene / α-olefin random copolymers in the total polymer is 5 to 40% by weight, preferably 8 to 30% by weight, more preferably 12 to 25% by weight.

Here, in the previous gas-phase polymerization step [a], propylene
When ethylene / butene-1 random copolymerization is carried out on the one hand, and when propylene / butene-1 random copolymerization is carried out in the latter gas phase polymerization step [b], for example, it is produced in the latter gas phase polymerization step [b]. The butene-1 content [mol%] in the propylene / butene-1 copolymer is determined as follows. That is, the copolymer composition before entering the later gas phase polymerization step [b] was ethylene a mol%, propylene b mol%, butene-1 cmol% and the latter gas phase polymerization step [b]. When the butene-1 content in the latter copolymer composition is d mol% and the polymerization rate in the later gas phase polymerization step [b] is w% by weight, the latter gas phase polymerization step [b] The butene-1 content [mol%] in the propylene / butene-1 copolymer produced in It is represented by.

The polymerization temperature is 20 to 150 ° C under the condition that the monomer is in the gas phase,
Preferably 30 to 100 ° C, more preferably 40 to 80
Perform at ℃. The polymerization pressure is not particularly limited as long as the monomer is in the gas phase at the use temperature, but it is 2 to 50 kg / cm ² , preferably 3 to 40 kg / cm ² , and more preferably 4 to 30 kg / cm ² .

It should be noted that in the gas phase polymerization step of the method of the present invention, the polymerization conditions such that a part of the monomers such as propylene and α-olefin are liquefied are not excluded.

The overall composition of the propylene-based block copolymer thus obtained is the repeating unit (f) derived from propylene.
Is usually 75 to 96 mol%, preferably 80 to 94 mol%, particularly preferably 84 to 92 mol%, and the repeating unit (g) derived from ethylene is usually 0.3 to 5 mol%,
The repeating unit (h) derived from α-olefin having from 4 to 20 carbon atoms preferably from 0.7 to 4.5 mol%, particularly preferably from 1 to 4 mol%, is usually 4 to 20 mol%.
It is in the range of mol%, preferably 5 to 15 mol%, particularly preferably 7 to 12 mol%. The propylene block copolymer obtained by the method of the present invention has a temperature of 135 ° C.
The intrinsic viscosity [η] measured in decalin is usually in the range of 0.5 to 6 dl / g, preferably 1 to 5 dl / g.

The crystallinity of the propylene-based block copolymer obtained by the method of the present invention is usually measured by the X-ray diffraction method.
It is in the range of 25 to 60%, preferably 30 to 55%, more preferably 35 to 50%. This characteristic value is a measure showing excellent tensile properties, and by combining with other characteristic values, it serves to provide the random copolymer having the above-mentioned excellent properties. Crystallinity is the thickness after 20 hours from molding 1.
It was determined by X-ray diffraction measurement of a 5 mm pressed sheet.

In the propylene-based block copolymer obtained by the method of the present invention, the amount of soluble components in the p-xylene solvent at 25 ° C is usually 30% by weight or less, preferably 25% by weight or less. In addition, the amount of extractable matter into the n-hexane solvent at 50 ° C is usually 10% by weight or less, preferably 8%.
It is not more than 6% by weight, more preferably not more than 6% by weight.

In the propylene-based block copolymer obtained by the method of the present invention, the soluble amount of the copolymer composition in a p-xylene solvent at 25 ° C is measured and determined by the following method. That is, 5 g of the copolymer sample and 1 p-xylene were added to a 2 liter flask equipped with a stirring blade and a reflux condenser, and the mixture was held under reflux of p-xylene for at least 2 hours to dissolve the sample in p-xylene. Then, after cooling the contents to 50 ° C under air cooling, the container is put in a cold water bath and rapidly cooled to 25-30 ° C. Transfer the container to a constant temperature bath kept at 25 ℃ and keep it in this state for 2 hours. A suspension of p-xylene containing the precipitated copolymer and dissolved polymer was over-separated with a G-4 glass filter, and the liquid was dried under reduced pressure of about 10 mmHg at 150 ° C until a constant weight was obtained. Collect the polymer dissolved in. The weight is measured, and the soluble content of the copolymer in the p-xylene solvent at 25 ° C. is calculated and determined as a percentage with respect to the weight of the sample copolymer.

In the propylene-based block copolymer obtained by the method of the present invention, the extraction amount of the copolymer composition in an n-hexane solvent at 50 ° C. is measured and determined by the following method.
That is, the copolymer sample and 1 n-hexane were added to a 2 liter flask equipped with a stirring blade and a reflux condenser, and the contents were heated to 50 ° C. and kept at the same temperature for 2 hours. The suspension was then over-separated with a G-4 glass filter while warm, and the solution was dried under reduced pressure of about 10 mmHg at 150 ° C until a constant weight was obtained, and the polymer was extracted with n-hexane at 50 ° C. To collect. The weight is measured, and the extracted amount of the copolymer in a solvent of 50 ° C. n-hexane is calculated and determined as a percentage with respect to the weight of the sample copolymer.

According to the present invention, it has essentially the same physical properties as polypropylene, and has a high yield of a copolymer having a low melting point of polypropylene.
It can be obtained in high yield and with a reduced amount of soluble copolymer by-products. Further, polymerization can be carried out without any trouble in the suspension polymerization process. Furthermore, since the copolymer yield per titanium is large, the catalyst removal operation after polymerization can be omitted.

The copolymer obtained according to the present invention has excellent heat sealability, heat seal impartability, transparency, and blocking resistance,
Since it has a low hydrocarbon-soluble content, it is suitable for use as a packaging film such as a film, especially a shrink film, for example, a food packaging film. Of course, it is also suitable for applications such as hollow bottles.

A polypropylene composite laminate is formed by laminating the propylene block copolymer of the present invention on one side or both sides of the surface of a substrate made of crystalline polypropylene. The crystalline polypropylene used as the base layer is, in addition to the crystalline propylene homopolymer, a crystalline propylene / α-olefin random copolymer containing a propylene component as a main component, for example, an ethylene content of 0.1 to 5 mol. % Propylene / ethylene random copolymer, ethylene content 0.1 to 4 mol% and 1-butene content 0.1 to 5 mol% propylene / ethylene / 1-butene random copolymer, 1-butene content Examples thereof include 0.1 to 5 mol% of propylene / 1-butene random copolymer. The intrinsic viscosity [η] of the crystalline polypropylene measured in decalin at 135 ° C. is usually 1.5 to 4
dl / g, preferably 1.7 to 3.5 dl / g, and the crystallinity measured by X-ray diffractometry is usually 50 to
It is in the range of 70%, preferably 55 to 70%. The base layer made of crystalline propylene may be unstretched or may be uniaxially or biaxially stretched.

The propylene-based block copolymer composition forming the heat-sealing layer in the polypropylene composite laminate,
In addition to the polymer component, a heat resistance stabilizer, a weather resistance stabilizer, a nucleating agent,
Lubricants, slip agents, antistatic agents, antiblocking agents, antifog agents, pigments, dyes, etc. may be added. The blending ratio is appropriate as long as the low temperature heat seal property and heat seal strength of the polypropylene composite laminate are not impaired.

As a method for producing a polypropylene composite laminate by laminating the propylene-based block copolymer of the present invention on one side or both sides of the substrate layer made of the crystalline polypropylene, the following method can be exemplified.

(1) A substrate made of crystalline polypropylene and the propylene-based block copolymer are coextruded to be laminated, and if necessary, further vertical axis stretching and / or horizontal axis stretching are performed simultaneously or simultaneously. Method.

(2) When the propylene-based block copolymer is extruded in a molten state and laminated on the surface of a non-stretched, uniaxially stretched or biaxially stretched crystalline polypropylene substrate, when the substrate is in an unstretched state Further, a method of performing uniaxial stretching or biaxial stretching as needed. Further, when the substrate is in a uniaxially stretched state, it is similarly extruded and laminated, and then, if necessary, further stretched in the same method as the substrate or in the cross direction.

(3) A method of laminating a film of the propylene-based block copolymer on the surface of a substrate made of crystalline polypropylene with an adhesive.

The polypropylene composite laminate formed by laminating the propylene-based block copolymer of the present invention on one side or both sides of a substrate made of crystalline propylene may have any shape, such as a laminated film or a laminated film. Examples thereof include a sheet, a laminated packaging bag, a laminated container, and other molded articles having heat sealability.

The substrate layer made of crystalline polypropylene that constitutes the propylene composite laminate is in a non-stretched state, a uniaxially stretched state, or a biaxially stretched state, as is clear from the examples of the laminating method described above. The propylene-based block copolymer layer may also be in a non-stretched state, a uniaxially stretched state, or a biaxially stretched state. Further, the base layer made of crystalline polypropylene and the layer made of propylene-based block copolymer of the polypropylene composite laminate may be constituted by any combination of the above-mentioned states.

The thickness of the base material layer made of crystalline polypropylene constituting the polypropylene composite laminate is arbitrary and is not particularly limited, but the thickness of the heat seal layer made of the propylene-based block copolymer is generally 0.1 to 50 μm. It is preferably in the range of 0.5 to 30μ. When the polypropylene composite laminate is a composite laminate film or a composite laminate sheet, the thickness of the substrate layer made of crystalline polypropylene is in the range of 5 to 200 μ, preferably 10 to 70 μ, and the propylene block The thickness of the heat-sealing layer made of a polymer is usually in the range of 0.1 to 50 μ, preferably 0.5 to 30 μ.

The present invention will be specifically described below with reference to examples. [Measurement of film blocking resistance and complete heat-sealing temperature] A method for determining the film blocking resistance and complete heat-sealing temperature of the obtained copolymer is 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 (made by Dyupon, trade name Kapton) sheets in this order
Lay out and place 0.8 g of sample in this center (cut out part)
Ku. Then Lumirror , Aluminum plate, press plate
Further stack in order (see 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 increased to 150 kg / cm ² G, and pressure heating is performed for 5 minutes. After depressurizing, remove the press plate from the press machine and transfer it to another press machine where the crimping part was kept at 30 ° C,
After pressure cooling at g / cm ² 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 2 pieces of film cut into 6 x 10 cm are stacked and
After it is sandwiched between two sheets of uniform thickness, it has a thickness of about 5 mm.
With a lath plate, further scissors under a load of 7 kg.
Leave for days (aging). Remove the film from the constant temperature bath
Then, after cooling to room temperature, one of the two-layer film is
Peel off part of the end, insert a Teflon stick here, and then peel it off
Clip the edge of the film to the top of the tensile tester.
Secure to the chuck. At the same time, attach the Teflon rod to the lower chuck.
It is fixed via a fixing bracket (see Fig. 2). Upper check
Fixed at 10 cm / min.
Freon When the two films are peeled off through the stick
Stress is measured using a tensile tester. Of the stress obtained
By dividing the value by the width of the film used (6 cm),
Film blocking, a measure of blocking resistance
Calculate the value (g / cm).

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 them with a 0.1mm-thick 2 Teflon film sandwiched between them. Heat sealing is performed by keeping the lower temperature of the heat sealer hot plate constant at 70 ° C and changing only the temperature of the upper part of the hot plate in steps of 5 ° C. Pressure during heat sealing is 2kg / c
m ² , heat seal time is 1 second, and the seal width is 5 mm (hence the seal area is 15 mm × 5 mm).

The heat-sealing strength is obtained by conducting a pulling test on the peeling strength of the film heat-sealed at the above-mentioned nuclear heat-sealing temperature 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 the plot of heat-sealing temperature vs. 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 titanium catalyst component (A)] 714 g of anhydrous magnesium chloride, 3.72 of decane and 3.5 l of 2-ethylhexyl alcohol were heated and reacted at 130 ° C. for 2 hours to form a uniform solution, and phthalic anhydride was added to this solution. 167g
Is added, 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, diisobutyl phthalate was added.
0.4 l is added and the mixture is kept at the same temperature for 2 hours with stirring. After the completion of the reaction for 2 hours, the solid portion was collected by heating, the solid portion was resuspended in 28 L of TiCl ₄ , and then 110 ° C again.
The reaction is heated for 2 hours. After completion of the reaction, the solid portion is again collected by heating, and the solid portion is thoroughly washed with decane and hexane at 110 ° C. 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 1 was added to a 2 liter glass reactor equipped with a stirrer in a nitrogen atmosphere.
After adding 5 mmol of triethylaluminum, 1 mmol of diphenylmethoxysilane and 0.5 mmol of the titanium catalyst component in terms of titanium atom, propylene was added to 11.
The mixture was fed for 5 hours at a rate of 1 Nl / Hr. During this period, the temperature was kept at 20 ° C. Five hours after starting the propylene feed, the propylene feed was stopped, nitrogen was fed instead, and the inside of the reactor was replaced with nitrogen. After the stirring was stopped and the mixture was left standing, the supernatant was removed and 1 purified hexane was newly added. This washing operation was repeated three times, then reslurried in hexane again, and transferred to a storage catalyst bottle. Pre-polymerization amount is 98g
-PP / g-catalyst.

(Polymerization) 7.5 kg of propylene, 2.3 kg of 1-butene, 38 Nl of ethylene and 25 Nl of hydrogen were added to an autoclave which had an internal volume of 50 l and which had been subjected to propylene substitution. Then, the temperature was raised to 50 ° C., and 25 mmol of triethylaluminum, 25 mmol of diphenyldimethoxysilane and 0.15 mmol of the titanium catalyst component subjected to the prepolymerization in terms of titanium atom were added, and the mixture was heated at 60 ° C. for 15 minutes.
Polymerization was performed for 1 minute. [A] Suspension polymerization step). Incidentally
The internal pressure of the autoclave is 0.1 kg /
The pressure was reduced to cm ² G to remove olefins in the autoclave. ([B] Flash process) After that, hydrogen 5Nl
And a propylene / butene-1 molar ratio of 30/70
The mixed gas was fed until the internal pressure of the autoclave reached 5.5 kg / cm ² G, and gas phase polymerization was started.

During the polymerization, the temperature is kept at 50 ℃, and the pressure is 5.5kg / cm ² G.
So that the propylene / 1-butene mixed gas was replenished. ([C] Gas Phase Polymerization Step) After 90 minutes of polymerization, 5 ml of methanol was added to stop the polymerization and depressurize. The produced polymer was recovered and dried overnight at 60 ° C. under a reduced pressure of 300 mmHg. The yield of the obtained white powdery polymer is 3.2 kg,
Apparent bulk specific gravity is 0.34 g / ml, ethylene content is 2.3 mol%,
The 1-butene content was 9.7 mol%, the MFR was 5.6 dg / min, the n-decane soluble part amount was 19.3% by weight, and the xylene soluble part amount at 25 ° C was
The amount of n-hexane extracted at 24.3% by weight and 50 ° C was 4.8% by weight. The film produced by the method described above has a blocking property of 16 g / cm and a complete heat-sealing temperature of 113.
It was ℃.

On the other hand, according to the analysis of each stage, the ethylene content of the copolymer after the [Ro] flush process was 2.8 mol% and the butene-1 content was 5.8 mol%, and therefore 1-butene / (1-butene + ethylene ) Was 0.67. In addition, the polymerization rate in the vapor phase polymerization step [C] was 23% by weight. Therefore, the content of 1-butene in the copolymer produced in the [ha] gas phase polymerization step was 24 mol%.

Example-2 Polymerization was carried out according to the method of Example-1 except that the conditions at the time of polymerization were changed to those shown in Table 1. The results are shown in Table 1.

Examples-3,4,5 The diphenyldimethoxysilane used as an electron donor in Example 1 was replaced with the compounds shown in Table 1, and the polymerization was performed according to the conditions shown in Table 1. The results are shown in Table-2.

Example -6 After high-speed stirrer [Preparation of titanium catalyst component (A)] internal volume 2l of the (manufactured by Tokushu Kika Kogyo Co., Ltd.) was sufficiently N ₂ substitutions, purified kerosene 700 ml, commercially available MgCl ₂ 10 g, ethanol 24.2g and items 3 g of the name Emazol 320 (Kao Atlas, sorbitan distearate) was added, the system was heated under stirring, and the system was stirred at 120 ° C. at 800 rpm for 30 minutes. 2 liters of refined kerosene 1 pre-cooled to -10 ° C was added using a Teflon tube with an inner diameter of 5 mm under high-speed stirring.
The liquid was transferred to a glass flask (with a stirrer). The produced solid was collected by filtration and thoroughly washed with hexane to obtain a carrier.

After suspending 7.5 g of the carrier in 150 ml of titanium tetrachloride at room temperature, 4.5 ml of di-n-octyl phthalate was added, and the suspension was kept at 120 ° C. for 2 hours.
After stirring and mixing for an hour, collect the solid part by filtration
It was suspended in 1 part of titanium tetrachloride and again stirred and mixed at 130 ° C. for 2 hours. A solid reaction product was collected from the reaction product in excess and washed with a sufficient amount of purified hexane to obtain a solid catalyst component [A]. The particle size of the catalyst was 64 μm and the geometric standard deviation was 1.4.

[Preliminary Polymerization] It was carried out in the same manner as in Example 1.

The prepolymerization was 89 pp / g-catalyst.

[Polymerization] Polymerization was carried out under the conditions shown in Table 1.

The results are shown in Table 1.

[Effect of the Invention] According to the present invention, as compared with the currently known propylene-based block copolymers, the heat-sealability, heat-sealability, transparency, and blocking resistance are excellent, and the hydrocarbon-soluble content is high. Less propylene block copolymer is obtained.

Further, the propylene-based block copolymer of the present invention has heat sealability, blocking resistance, and heat seal aging resistance comparable to those of currently known polyolefin compositions.

As described above, the propylene-based block copolymer of the present invention is superior to the currently known polyolefin compositions in heat sealability, blocking resistance, even without forming a composition with other (co) polymers. Since it has resistance to heat seal change over time, it is not necessary to prepare a composition, and the manufacturing cost can be further reduced.

[Brief description of drawings]

FIG. 1 shows the schematic cross-sectional view of the film preparation method used for the test, FIG. 2 shows the schematic cross-sectional view of the film blocking value measurement method, and FIG. 3 shows the heat-sealing strength measurement method. Fig. 4 shows the relationship between heat sealing temperature and peel strength.

Claims (1)

[Claims] 1. A highly active and high steric compound containing (A) magnesium, titanium, halogen and an electron donor as essential components, having an average particle size of about 5 to about 200 μ and a geometric standard deviation value of less than 2.1. In the presence of a catalyst formed from a regular titanium catalyst component, (B) an organometallic compound catalyst component of a metal of Groups 1 to 3 of the periodic table, and (C) an electron donor catalyst component, the titanium catalyst component (A) Propylene, ethylene and carbon atoms of 4 to 4 in the presence of an α-olefin prepolymerization catalyst obtained by prepolymerizing α-olefin having 2 to 10 carbon atoms in the range of 1 to 2000 g per gram. 20
And the step of copolymerizing α-olefin in the suspension polymerization step [a] using liquid propylene as a solvent, and then the liquid unreacted raw material in the polymerization reaction mixture obtained in the suspension polymerization step is flashed to be vaporized. Depending on the process, the number of repeating units (a) derived from propylene was 86.
To 97 mol%, 0.5 to 6 mol% of the repeating unit (b) derived from ethylene and 2 to 13 mol% of the repeating unit (c) derived from α-olefin having 4 to 20 carbon atoms. , The molar ratio c / (b + c) is
A flashing step (b) for producing a propylene-based random copolymer [I] in the range of 0.3 to 0.9, the presence of the propylene-based random copolymer [I], and conditions under which the reaction system forms a gas phase. Below, propylene and α-olefin having 4 to 20 carbon atoms are copolymerized to obtain 10 to 90 mol% of repeating units (d) derived from propylene and 4 to 4 carbon atoms.
20 repeating units (e) derived from α-olefin are 10
To 90 mol% of the low-crystalline propylene random copolymer [II] to form a vapor phase polymerization step [C], and a method for producing a propylene block copolymer.