JP2001206914A - Method for producing propylenic random copolymer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for producing a propylenic random copolymer, by which a reactor can stably be operated without generating the fouling of the wall surfaces and piping wall surfaces of the reactor or post-treatment systems by the polymer without coagulating the powder particles of the polymer, even when the low melting point propylenic random copolymer is continuously produced. SOLUTION: This method for producing a propylenic random copolymer, characterized by continuously polymerizing the propylenic random copolymer having a melting point (Tm) of 115 to 165 deg.C measured with a differential scanning calorimeter(DSC), under conditions simultaneously satisfying the following (1) to (3). (1) Propylene is copolymerized with the other α-olefin in the coexistence of a metallocenic catalyst. (2) The polymerization temperature T ( deg.C) satisfies the following expression. 55<=T<=75, T<=1.42×Tm-100. (3) The Ws/Wp weight ratio of the amount (Ws) of an inert solvent to the amount (Wp) of the propylene monomer existing in the polymerization tank is <=0.02.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for producing a propylene random copolymer, and more particularly to a method for continuously producing a low melting point propylene random copolymer. Things.

[0002]

2. Description of the Related Art Various methods have been proposed for producing a propylene-based random copolymer using a metallocene-based catalyst.
JP-A-62-119215, JP-A-2-173015,
JP-A-2-247207). However, at present, studies on the problems in the case of continuous polymerization and methods for solving the problems are not yet sufficient.

For example, when a low-melting propylene-based random copolymer is continuously produced, fouling occurs on the wall surface of a reactor or a post-treatment system or on the wall surface of a pipe, or powder particles agglomerate. There is a problem that long-term stable operation is difficult.

[0004] The reason for this is that in the production of a low-melting propylene random copolymer, low crystalline components or catalyst components in the produced powder are extracted by the reaction medium or an inert solvent contained in the reaction medium, and are extracted from the wall surface. It is conceivable to precipitate or to aggregate the particles.

Although the amount of these precipitates or agglomerates is very small, there is a problem that they are accumulated in a long-time continuous polymerization, and finally the operation cannot be continued.

The inert solvent is necessarily introduced into the polymerization reaction system as a diluting solvent for the organoaluminum which is a cocatalyst and / or a deactivation inhibitor or as a slurrying medium for uniformly dispersing the polymerization catalyst. Therefore, when producing a propylene-based random copolymer containing a low-crystal component soluble in these solvents, there is a very serious problem.

[0007]

According to the present invention, even when a low-melting propylene random copolymer is continuously produced, the polymer is deposited on the wall of a reactor or post-treatment system tank or pipe. An object of the present invention is to provide a method for producing a propylene-based random copolymer capable of performing a long-term stable operation without causing fouling or agglomeration of polymer powder particles.

[0008]

Means for Solving the Problems The present inventors have conducted various studies, and as a result, by setting specific polymerization conditions,
The present inventors have succeeded in finding a polymerization method that can solve the above-mentioned problems, and have accomplished the present invention.

That is, the present invention provides the following (1) to (3)
Scanning differential scanning calorimeter (DS)
It is intended to provide a method for producing a propylene-based random copolymer characterized by continuously polymerizing a propylene-based random copolymer having a melting point (Tm) of 115 to 165 ° C according to C).

(1) Copolymerization of propylene and another α-olefin in the presence of a metallocene catalyst (2) The polymerization temperature T (° C.) satisfies the following equation: 55 ≦ T ≦ 75T ≦ 1. 42 × Tm-100 (3) Amount of propylene monomer (W
The ratio Ws / Wp (weight ratio) of the amount of inert solvent (Ws) to p) is 0.02 or less.

In the above method for producing a propylene-based random copolymer, an olefin polymerization catalyst comprising the following components [A] and [B] and, if necessary, component [C] is used as the metallocene-based catalyst. To provide a method for producing a propylene-based random copolymer.

Component [A] A transition metal compound of Groups 4 to 6 of the Periodic Table having at least one conjugated five-membered ring ligand Component [B] Ion-exchanged layered silicate Component [C] Organoaluminum compound

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION The propylene random copolymer produced by the polymerization method of the present invention comprises at least one member selected from the group consisting of propylene as a main component and ethylene and an olefin having 4 or more carbon atoms as a comonomer. Are polymerized, and the melting point (T by differential scanning calorimetry (DSC)
m) is 115-165 ° C, preferably 115-135 ° C.
It is a low-melting-point propylene-based random copolymer at ℃.

Examples of the olefin having 4 or more carbon atoms include:
Examples thereof include 1-butene, 1-hexene, 4-methyl-1-pentene, 1-octene and the like. The amount of the comonomer composed of ethylene and an olefin having 4 or more carbon atoms is selected in such a range that the melting point (Tm) measured by a differential scanning calorimeter (DSC) falls within the range of the present invention. The polymerization method of the present invention can be carried out by a known bulk polymerization method or a continuous polymerization method of a gas phase polymerization method, and is preferably carried out by a bulk polymerization method. Further, the polymerization of the present invention can be carried out in one stage or in multiple stages.

The polymerization temperature T (° C.) is a polymerization temperature that satisfies the following equation.

55 ≦ T ≦ 75 T ≦ 1.42 × Tm-100

When the polymerization temperature T (° C.) is lower than this temperature range, the amount of polymer produced per catalyst unit or per unit volume of the polymerization reactor decreases, which is uneconomical. On the other hand, if the polymerization temperature T exceeds this temperature range, in the case of bulk polymerization, the pressure in the polymerization tank becomes high, which is not preferable for safety and is not practical.

The ratio Ws of the amount of the inert solvent (Ws) to the amount of the propylene monomer (Wp) present in the polymerization tank is represented by Ws
/ Wp (weight ratio) is 0.02 or less, preferably 0.02
1 or less. Here, Wp and Ws are represented by the following equations.

Wp = amount of propylene supplied-amount of propylene monomer incorporated in the copolymer Ws = amount of inert solvent supplied

In the present invention, the inert solvent present in the polymerization system is the following (a) to (e) and is substantially liquid in the polymerization system.

(A) Solvent used for uniformly dissolving or dispersing the polymerization catalyst (b) Solvent used for diluting or uniformly dispersing the cocatalyst for activating the metallocene complex (c) Polymerization Solvent used for diluting or uniformly dispersing the deactivation inhibitor in the system (d) When adding a substance other than the above (a) to (c) into the polymerization tank, dilute or uniformly disperse the substance. (E) As a monomer or comonomer, a non-polymerizable hydrocarbon solvent contained in ethylene or an olefin having 3 or more carbon atoms supplied to a polymerization tank

Specific examples of these inert solvents include:
(A) linear aliphatic hydrocarbons such as butane, pentane, hexane, heptane, octane, and decane; (ii) branched aliphatic hydrocarbons such as isopentane and isooctane;
(C) Alicyclic hydrocarbons such as cyclohexane and methylcyclohexane, and (d) aromatic hydrocarbons such as benzene, toluene and xylene. These inert solvents may be a mixture of a plurality of hydrocarbon compounds,
Specific examples include (e) naphtha fractions such as liquid paraffin. The inert solvent may be a mixture of the above (a) to (e). Further, hydrocarbons in which some of carbon atoms or hydrogen atoms of hydrocarbons are substituted with silicon atoms, halogen atoms, or the like can be used as long as polymerization activity and obtained polymer properties are not affected. The amount of the inert solvent present in the polymerization system means the total weight of (a) to (e) described above.

The amount of the propylene monomer present in the polymerization tank means the total weight of the propylene monomer present in the liquid phase and the gas phase in the bulk polymerization method, and the amount of the propylene monomer present in the gas phase in the gas phase polymerization. Means weight.

In the case of multistage polymerization, it is defined as the amount of an inert solvent or the amount of a propylene monomer in each reaction vessel.

As the metallocene catalyst used in the present invention, known catalysts can be used. Specifically, the metallocene catalyst is obtained by combining the components [A] and [B] described below and [C] used as required. Preferred catalysts are preferred.

Component [A] Metallocene complex: transition metal compound of Group 4 to 6 of the periodic table having at least one conjugated five-membered ring ligand Component [B] Promoter: Compound [B] and metallocene complex [A] A compound capable of activating the metallocene complex [A] by reacting component [C] an organoaluminum compound

The metallocene catalyst may or may not have been subjected to a prepolymerization treatment. Further, among the olefin polymerization catalysts, it is preferable to use a supported metallocene catalyst. Specific examples of the carrier include inorganic oxides such as silica and alumina, and organic substances such as a polypropylene-based polymer. For example, the carrier of components [A] and [B] may be replaced with a component [C] an organoaluminum compound. And the like.

A particularly preferred example of the supported metallocene catalyst is an ion-exchangeable layered silicate in which a carrier also functions as a promoter. Specifically, it is obtained by combining component [A], component [B] described below, and component [C] added as needed.

Component [A] Metallocene complex: transition metal compound of Group 4 to 6 of the periodic table having at least one conjugated five-membered ring ligand Component [B] Promoter: ion-exchange layered silicate Component [C ] Organoaluminum compounds

As the above component [A], specifically,
The compound represented by the following general formula [1] can be used.

[0031] _{Q (C 5 H 4-a} R 1 a) (C 5 H 4-b R 2 b) MXY [1]

In the above general formula [1], Q represents a binding group bridging two conjugated five-membered ring ligands. M represents a transition metal belonging to Groups 4 to 6 of the periodic table, and among them, titanium, zirconium and hafnium are preferable.

X and Y are each independently hydrogen,
Halogen group, C1-20 hydrocarbon group, C1
It represents an oxygen-containing hydrocarbon group having 20 carbon atoms, a nitrogen-containing hydrocarbon group having 1 to 20 carbon atoms, a phosphorus-containing hydrocarbon group having 1 to 20 carbon atoms, or a silicon-containing hydrocarbon group having 1 to 20 carbon atoms.

R ¹ and R ² each independently represent a hydrocarbon group having 1 to 20 carbon atoms, a halogen group, a hydrocarbon group containing 1 to 20 carbon atoms, an alkoxy group, an aryloxy group, a silicon-containing hydrocarbon group. Group, a phosphorus-containing hydrocarbon group, a nitrogen-containing hydrocarbon group or a boron-containing hydrocarbon group. Further, two adjacent R ¹ or two R ² may be bonded to each other to form a C _{4 to} C ₁₀ ring. a and b
Is an integer satisfying 0 ≦ a ≦ 4 and 0 ≦ b ≦ 4.

The linking group Q bridging between the two conjugated five-membered ring ligands is, for example, an alkylene group, an alkylidene group,
Examples thereof include a silylene group and a germylene group. These may be those in which a hydrogen atom is substituted by an alkyl group, halogen, or the like.

Specific examples of the metallocene complex include the following compounds.

(1) Methylene bis (cyclopentadienyl) zirconium dichloride (2) Methylene (cyclopentadienyl) (3,4-dimethylcyclopentadienyl) zirconium dichloride (3) Isopropylidene (cyclopentadienyl)
(3,4-dimethylcyclopentadienyl) zirconium dichloride (4) ethylene (cyclopentadienyl) (3,5-dimethylpentadienyl) zirconium dichloride (5) methylenebis (indenyl) zirconium dichloride (6) ethylenebis ( 2-methylindenyl) zirconium dichloride (7) ethylene 1,2-bis (4-phenylindenyl) zirconium dichloride (8) ethylene (cyclopentadienyl) (fluorenyl) zirconium dichloride (9) dimethylsilylene (cyclopentadiene) (Enyl) (tetramethylcyclopentadienyl) zirconium dichloride (10) dimethylsilylenebis (indenyl) zirconium dichloride (11) dimethylsilylenebis (4,5,6,7-tetrahydroindenyl Zirconium dichloride (12) dimethylsilylene (cyclopentadienyl)
(Fluorenyl) zirconium dichloride (13) Dimethylsilylene (cyclopentadienyl)
(Octahydrofluorenyl) zirconium dichloride (14) methylphenylsilylenebis [1- (2-methyl-4,5-benzo (indenyl)] zirconium dichloride (15) dimethylsilylenebis [1- (2-methyl-
4,5-benzoindenyl)] zirconium dichloride (16) dimethylsilylenebis [1- (2-methyl-4)
H-azulenyl)] zirconium dichloride (17) dimethylsilylenebis [1- (2-methyl-4)
-(4-chlorophenyl) -4H-azulenyl)] zirconium dichloride (18) dimethylsilylenebis [1- (2-ethyl-4
-(4-chlorophenyl) -4H-azulenyl)] zirconium dichloride (19) dimethylsilylenebis [1- (2-ethyl-4
-Naphthyl-4H-azulenyl)] zirconium dichloride (20) diphenylsilylenebis [1- (2-methyl-
4- (4-chlorophenyl) -4H-azulenyl)] zirconium dichloride (21) dimethylsilylenebis [1- (2-methyl-4
-(Phenylindenyl))] zirconium dichloride (22) dimethylsilylenebis [1- (2-ethyl-4)
-(Phenylindenyl))] zirconium dichloride (23) dimethylsilylenebis [1- (2-ethyl-4)
-Naphthyl-4H-azulenyl)] zirconium dichloride (24) dimethylgermylene bis (indenyl) zirconium dichloride (25) dimethylgermylene (cyclopentadienyl)
(Fluorenyl) zirconium dichloride

The same compounds as described above can also be used for other transition metal compounds of the fourth, fifth and sixth groups such as titanium compounds and hafnium compounds. These compounds may be mixed for the catalyst component and the catalyst of the present invention.

The component [B] ion-exchangeable phyllosilicate is
Not only natural products but also artificial products may be used. A clay compound can be used as the ion-exchange layered silicate. Specific examples of the clay compound include, for example, the following described in “Clay Mineralogy” by Haruo Shiramizu, Asakura Shoten (1995) Layered silicates are mentioned.

(1) Dickite, nacrite, kaolinite, anoxite, and 1: 1 are main constituent layers.
Kaolin group such as metahalloysite, halloysite, serpentine group such as chrysotile, lizardite, antigolite, and the like. Smectites such as stevensite, vermiculites such as vermiculite,
Mica such as mica, illite, sericite, chlorite, attapulgite, sepiolite, palygorskite, bentonite, pyrophyllite, talc, chlorite

The silicate used in the present invention includes the above (1)
The layered silicate which formed the mixed layer of (2) may be used.
In the present invention, the silicate as the main component is preferably a silicate having a 2: 1 type structure, more preferably a smectite group, and particularly preferably montmorillonite.

The silicate used in the present invention can be used as is without any treatment within the scope of the claims of the present invention. It is possible and preferred that the inorganic silicate is specified. Here, the chemical treatment can be any of a surface treatment for removing impurities adhering to the surface and a treatment that affects the structure of the clay.

Specific examples include acid treatment, alkali treatment, salt treatment and the like. The acid treatment increases the surface area by removing impurities on the surface and eluting cations such as Al, Fe, and Mg in the crystal structure. The alkali treatment destroys the crystal structure of the silicate, causing a change in the structure. In the salt treatment and the organic substance treatment, an ion complex, a molecular complex, an organic derivative, and the like are formed, and the surface area and the interlayer distance can be changed. By utilizing the ion exchange property and replacing the exchangeable ions between the layers with another large bulky ion, it is also possible to obtain a layered material in which the layers are expanded.

In the present invention, at least 40%, preferably at least 60%, of the exchangeable Group 1 metal cations contained in the ion-exchanged layered silicate before being treated with salts,
It is preferable to perform ion exchange with a cation dissociated from the following salts.

A salt treatment for such ion exchange
The salts used in the process are selected from the group consisting of group 2-14 atoms.
Contains cations containing at least one selected atom
And preferably a group consisting of atoms of groups 2 to 14
A cation containing at least one atom selected from the group consisting of:
Selected from the group consisting of halogen atoms, inorganic acids and organic acids
Compound comprising at least one anion
And more preferably selected from the group consisting of group 2-14 atoms.
A cation containing at least one type of atom, Cl,
Br, I, F, PO_Four, SO_Four, NO_Three, CO_Three, C_TwoO_Four,
ClO_Four, OOCCH_Three, CH_ThreeCOCHCOCH_Three, OC
l_Two, O (NO_Three)_Two, O (ClO_Four)_Two, O (SO_Four), O
H, O_TwoCl_Two, OCI_Three, OOCH, OOCCH_TwoC
H_Three, C_TwoH_FourO _FourAnd C₆H_FiveO₇Selected from the group consisting of
And at least one anion.

Specifically, LiCl, LiNO ₃ , Li ₂
SO ₄ , Li ₂ C ₂ O ₄ , NaCl, Na ₂ SO ₄ , Na ₂ C ₂
O ₄ , NaNO ₃ , KCl, K ₂ SO ₄ , K ₂ C ₂ O ₄ , Ca
Cl ₂ , CaSO ₄ , Ca (NO ₃ ) ₂ , MgCl ₂ , Mg
Br ₂ , Mg (NO ₃ ) ₂ , MgSO ₄ , Mg ₃ (P
O ₄ ) ₂ , Ti (SO ₄ ) ₂ , TiF ₄ , TiCl ₄ , VOS
O ₄ , VOCl ₃ , VCl ₃ , Fe (OOCH ₃ ) ₂ , Fe
(CH ₃ COCHCOCH ₃ ) ₃ , Fe (ClO ₄ ) ₃ , F
ePO ₄ , FeSO ₄ , Zn (NO ₃ ) ₂ , ZnSO ₄ , Zn
(OOCH ₃ ) ₂ , AlF ₃ , AlCl ₃ , AlBr ₃ , A
11 ₃ , Al ₂ (SO ₄ ) ₃ , SnSO ₄ , Sn (NO ₃ ) ₂ , trimethylammonium, triethylammonium, N,
N-dimethylanilinium, N, N-diethylanilinium, pyridinium, triphenylphosphonium, diphenyloxonium and the like can be mentioned.

The acid treatment removes impurities on the surface and elutes a part of cations such as Al, Fe, and Mg having a crystal structure to obtain a silicate defined in the present invention.

The acid used in the acid treatment is preferably selected from hydrochloric acid, sulfuric acid, nitric acid, oxalic acid, phosphoric acid and acetic acid. The salt and the acid used for the treatment may be two or more. When the salt treatment and the acid treatment are combined, there are a method of performing the salt treatment and then performing the acid treatment, a method of performing the acid treatment and then performing the salt treatment, and a method of simultaneously performing the salt treatment and the acid treatment.

The treatment conditions with salts and acids are not particularly limited, but usually, the concentration of salts and acids is 0.1 to 0.1%.
A substance constituting at least one compound selected from the group consisting of ion-exchanged phyllosilicates under the conditions of 80% by weight, a treatment temperature of room temperature to a boiling point and a treatment time of 5 minutes to 24 hours. By controlling the elution of silicate, it is possible to produce a silicate having a structure defined in the present invention.

Further, salts and acids are generally used in an aqueous solution. As the treatment conditions, it is preferable to perform the acid treatment or the treatment in the presence of an acid and a salt at least once,
The reaction is carried out at an acid concentration of 1 mol / L or more and 12 mol / L or less, preferably 2 mol / L or more and 8 mol / L or less. As described above, it is possible to obtain a desired silicate by controlling the processing temperature and the processing time under the condition that the acid concentration is relatively high, which is preferable. For example, when sulfuric acid is used, preferably 18% by weight or more and 58% by weight.
The following concentrations are obtained.

In the present invention, the above-mentioned acid treatment or the coexistence treatment of an acid and a salt is preferably carried out, but the shape may be controlled by pulverization or granulation before, during or after the treatment. Further, a chemical treatment such as an alkali treatment or an organic substance treatment may be used in combination.

As the alkaline treating agent, LiOH, Na
OH, KOH, Mg (OH) ₂ , Ca (OH) ₂ , Sr
(OH) ₂ , Ba (OH) _{2 and the} like.

It is preferable to use spherical particles having an average particle diameter of 5 μm or more. More preferably, spherical particles having an average particle size of 10 μm or more are used. More preferably, spherical particles having an average particle diameter of 10 μm or more and 100 μm or less are used. The average particle size specifically indicates a value obtained by measuring in ethanol using a laser micronizer LMS-24 manufactured by Seishin Enterprise Co., Ltd. The silicate may be a natural product or a commercially available product as it is, as long as the shape of the particles is spherical, or granulation, sizing, or the like in which the shape and size of the particles are controlled by sorting or the like. Is also good.

These silicates usually contain adsorbed water and interlayer water. In the present invention, it is preferable to use the water after removing these adsorbed water and interlayer water.

Here, the adsorbed water is water adsorbed on the surface of the silicate compound particles or the crystal fracture surface, and the interlayer water is water existing between the crystal layers. In the present invention, these adsorbed water and / or interlayer water can be removed by heat treatment before use.

The method for heat treatment of the silicate adsorbed water and interlayer water is not particularly limited, and methods such as heat dehydration, heat dehydration under gas flow, heat dehydration under reduced pressure, and azeotropic dehydration with an organic solvent are used. . Although the temperature at the time of heating cannot be specified unconditionally depending on the type of silicate, it is 100 ° C. or higher, preferably 150 ° C. or higher so that interlayer water does not remain. Although it depends on the heating time, for example, 800 ° C. or more) is not preferable.

In the case of thermal dehydration under a gas flow, an inert gas is usually used, but drying with air is also possible.
The heating time depends on the drying temperature, but is usually 1 minute or more, preferably 1 hour or more. At that time, the water content of the silicate after removal is 3% by weight or less, preferably 1% by weight when the water content is 0% by weight when dehydrated for 2 hours at a temperature of 200 ° C. and a pressure of 1 mmHg. It is preferable that the content be not more than weight%.

As described above, in the present invention, a particularly preferred silicate is an ion-exchangeable layered silicate having a water content of 1% by weight or less obtained by performing a salt treatment and / or an acid treatment. .

Component [C] is an organoaluminum compound. Organic aluminum compounds used as component [C] in the present invention, the compound represented by formula ^{_{(AlR 4 p X 3-p}} ) q is suitable.

In the present invention, it goes without saying that the compounds represented by this formula can be used alone, in combination of two or more or in combination. This use is possible not only at the time of catalyst preparation but also at the time of prepolymerization or polymerization. In this formula, R ⁴ represents a hydrocarbon group having 1 to 20 carbon atoms, and X represents a halogen, hydrogen, an alkoxy group, or an amino group. p is an integer of 1 to 3, and q is an integer of 1 to 2. R ⁴ is preferably an alkyl group, X is chlorine when it is a halogen, an alkoxy group having 1 to 8 carbon atoms when it is an alkoxy group, and 1 to 8 carbon atoms when it is an amino group. Is preferred. Among these, a trialkylaluminum and a dialkylaluminum hydride having p = 3 and q = 1 are preferable. More preferably, R ⁴ is a trialkyl aluminum having 1 to 8 carbon atoms.

The metallocene catalyst used in the present invention comprises:
It is desirable to perform a preliminary polymerization treatment before the main polymerization is performed. As monomers to be subjected to the prepolymerization, ethylene,
Α-olefins such as propylene, 1-butene and 1-hexene, diene compounds such as 1,3 butadiene, styrene,
A vinyl compound such as divinylbenzene can be used.

[0062]

The following examples further illustrate the present invention, but the present invention is not limited by these examples without departing from the gist thereof.

(Method of Measuring Polymer Aggregation Amount) Polymer 1
00g, and sieve 1700 μm (JIS-Z-8
801) Weigh the above polymer.

(Method of measuring polymer bulk density) ASTM
It measured according to D1895-69.

(MFR (Melt Flow Rat)
e)) Melt flow rate of JIS-K-6758 polypropylene test method (condition: 230 ° C, load: 2.16K)
gf).

(Measurement method of Tm by DSC) A sample (about 5 mg) was taken using a DSC measurement device manufactured by Seiko Co., Ltd.
After melting at 00 ° C. for 5 minutes, the temperature is lowered to 40 ° C. at a rate of 10 ° C./min for crystallization, and then the temperature is raised to 200 ° C. at a rate of 10 ° C./min. Was evaluated.

(Heat Sealability) Using a heat seal bar of 5 mm × 200 mm, a sample having a width of 15 mm was taken from a heat-sealed sample under the conditions of a heat seal pressure of 1 kg / cm ² and a heat seal time of 2 seconds at each temperature setting. , Pulling speed of 500 using a shopper type testing machine
It was separated at a rate of mm / min and evaluated by the sealing temperature at which the load became 300 g (unit: ° C.). The smaller the value, the better the heat sealing property.

(Blocking property) The same surface of a sample film having a width of 2 cm and a length of 15 cm was overlapped over a length of 5 cm from the obtained film, and subjected to a load of 100 g / cm ² under an atmosphere of a temperature of 40 ° C. for 24 hours. After adjusting the condition,
After removing the load and sufficiently adjusting the temperature to 23 ° C., the force required for shearing and peeling the sample at a speed of 200 mm / min was determined using a tensile tester (unit: g / 10 cm ² ). The smaller this value is, the better the blocking property is.

(Production of Resin Composition) Tetrakis [methylene-alkyl] was used as an antioxidant with respect to 100 parts by weight of the propylene-ethylene-random copolymer obtained by the method described later.
0.05 parts by weight of 3- (3 ′, 5′-di-t-butyl-4-hydroxyphenyl) propionyloxy] ethyl isocyanate, tetrakis (2,4-di-t-butylphenyl) -4,4 ′ 0.05 parts by weight of biphenylenediphosphonite, 0.05 parts by weight of calcium stearate as a neutralizing agent, 0.2 parts by weight of synthetic silica (average particle size: 2.0 μm) as an antiblocking agent, and erucamide as a lubricant Was mixed at high speed at room temperature for 2 minutes using a Henschel mixer,
The mixture was melted and kneaded at 230 ° C. by a 50 mmφ extruder, extruded into a strand, cooled, cut and formed into a pellet.

(Production of Film) Using this resin composition as a raw material, an extruder having a diameter of 35 mmφ, a 300 mm width T die,
Using a T-die method film forming machine equipped with an air knife and a chill roll, molding was performed at an extruded resin temperature of 230 ° C., a chill roll temperature of 30 ° C., and a film formation take-off speed of 21 m / min to obtain an unstretched film having a thickness of 25 μm.

Example 1 (Chemical treatment of silicate) 1130 mL of distilled water and then 750 g of concentrated sulfuric acid were placed in a 3 L glass flask equipped with a stirring blade.
Is slowly added, 300 g of montmorillonite (Benclay SL, manufactured by Mizusawa Chemical Co., Ltd .; average particle size = 25 μm, particle size distribution = 10 μm to 60 μm) is dispersed, the temperature is raised to 90 ° C. over 1 hour, and the temperature is maintained for 5 hours. After that, 1
Cooled to 50 ° C. over time. This slurry was filtered under reduced pressure to collect a cake.

4 L of distilled water was added to the cake, and the cake was reslurried and filtered. This washing operation was repeated four times. The pH of the final washing solution (filtrate) was 3.42. The recovered cake was dried overnight at 110 ° C. under a nitrogen atmosphere. The weight after drying was 227 g.

The composition of the chemically treated montmorillonite was as follows: Al was 5.0%, Mg was 0.8%, and Fe was 1.6%.
%, And 37.7% of Si.

(Preparation of Catalyst) The following operation was carried out using a solvent and a monomer which had been deoxygenated and dehydrated under an inert gas.

The previously treated montmorillonite was dried under reduced pressure at 200 ° C. for 2 hours.

200 g of the dried montmorillonite obtained above was introduced into a glass reactor having an inner volume of 3 L and equipped with a stirring blade, normal heptane and a heptane solution of triethylaluminum (10 mmol) were added, and the mixture was stirred at room temperature. After 1 hour, wash with normal heptane (residual liquid ratio 1%
) And the slurry was adjusted to 2000 mL.

Next, (r) -dimethylsilylenebis [2-methyl-4- (4-chlorophenyl) -4
[H-azulenyl] zirconium dichloride 3 mmol of a toluene slurry 870 mL and triisobutylaluminum (30 mmol) of a heptane solution 42.6 mL were reacted at room temperature for 1 hour, added to the montmorillonite slurry, and stirred for 1 hour.

Subsequently, the internal volume 1 sufficiently replaced with nitrogen
Normal heptane 2.1 in a 0 L stirred autoclave
L was introduced and maintained at 40 ° C. The montmorillonite / complex slurry prepared above was introduced therein. Temperature 40
When the temperature became stable at ℃, propylene was fed at a rate of 100 g / hour, and the temperature was maintained. After 4 hours, the supply of propylene was stopped and maintained for another 2 hours. About 3 L of the supernatant was removed from the recovered prepolymerized catalyst slurry, and a solution of triisobutylaluminum (30 mmol) in heptane was added.
After adding 70 mL and stirring for 10 minutes, it was dried at 40 ° C. under reduced pressure. By this operation, a prepolymerized catalyst containing 1.43 g of polypropylene per 1 g of the catalyst was obtained.

(Polymerization) FIG. 2 is a schematic diagram showing an example of a continuous bulk polymerization apparatus used in the present invention. Liquid propylene, ethylene and hydrogen are supplied to the reactor 1 shown in FIG. 2 and triisobutylaluminum (TIBA) is supplied.
Hexane diluted solution was continuously supplied through the pump 2 to maintain the internal temperature at 70 ° C. The supply amount of propylene is 1
10 kg / hr, ethylene supply 1.5 kg / hr
And the supply amount of hexane based on the supply of the TIBA diluted solution in hexane was 0.5 L / hr. The above prepolymerized catalyst was used as a slurry of liquid paraffin (White Rex 335 manufactured by Tonen Corporation). The concentration is 20w
t%.

The catalyst slurry was supplied to the reactor at a constant rate per hour to obtain a 20 kg / hr propylene / ethylene random copolymer. The total weight (Ws) of hexane and liquid paraffin present in the system is 0.5 wt% based on the weight of propylene (Wp) present in the system.
% (Ws / Wp = 0.005). Under these conditions, there was no blockage, no fouling to the reactor, and no polymer aggregation, and stable operation was possible for about 5 days. The obtained propylene / ethylene random copolymer has an MFR =
8.7, Tm = 135 ° C., bulk density = 0.49 (g / c)
c) The amount of aggregated polymer of 1700 μ or more was 0.4%.

Comparative Example 1 The catalyst was 0.04 of hexane.
Polymerization was carried out in exactly the same manner as in Example 1 except that the slurry was a wt% slurry. At this time, the amount of hexane supplied together with the catalyst was 5.5 L / hr. The amount of hexane in the system was 4.4% with respect to propylene (Ws / Wp = 0.0
44). A production of about 20 kg / hr was obtained,
After 0 hr, the operation became impossible due to blockage of the powder extraction line and the degassing tank. The resulting powder had MFR = 6.9, Tm = 135 ° C., bulk density = 0.4
1 (g / cc), polymer aggregation amount of 1700 μ or more =
4.2%.

Reference Example 1 Batch polymerization was carried out such that the ratio of inert solvent / propylene in the polymerization system was the same as in Comparative Example 1.

After sufficiently replacing the inside of a 3 L stirred autoclave with propylene, 2.86 mL (2.02 mmol) of a triisobutylaluminum / n-heptane solution was used.
l) was added, followed by 35 mL of hexane.
Further, 15 g of ethylene, 35 mL of hydrogen, and 1500 mL of liquid propylene were introduced, and the temperature was raised to 70 ° C. and maintained at that temperature. 1.5 mL of normal heptane slurry of the prepolymerized catalyst and 15 mg of the catalyst (excluding the weight of the prepolymerized polymer) were injected to initiate polymerization. The total amount of hexane and n-heptane contained in the system was 4.6% based on propylene (Ws / Wp = 0.
046). The temperature in the tank was maintained at 70 ° C. One hour later, 5 ml of ethanol was added, the residual gas was purged, and the obtained polymer was dried. As a result, 189 g of a polymer was obtained. The catalyst activity is 12600 g-PP / g-catalyst.
It was time. Polymer BD = 0.47 (g / cc), M
FR = 4.5 (dg / min), Tm = 135 ° C.
Almost no agglomerated polymer was found, less than 0.2%.

Example 2 (Polymerization) Continuous polymerization was carried out in the same manner as in Example 1 except that the polymerization temperature was 60 ° C. and the amount of ethylene supplied was about twice. 1
9.5 kg / hour of a propylene / ethylene copolymer was obtained. The total amount of hexane and liquid paraffin contained in the system was 0.4 wt% (Ws /
Wp = 0.004). It was possible to operate stably without clogging, fouling to the reactor, or polymer aggregation for about 5 days. The obtained propylene / ethylene random copolymer had a MFR of 9.4, a Tm of 125 ° C.,
Bulk density = 0.49, amount of aggregation of 1700 µ or more = 0.8%
Met.

The physical properties of the polymer film obtained above are shown in Table 1.

[0086]

[Table 1]

[Brief description of the drawings]

FIG. 1 is a flowchart for assisting understanding of the present invention.

FIG. 2 is a longitudinal sectional view showing a continuous bulk polymerization apparatus used in Example 1.

[Explanation of symbols]

 1: Reactor 2: Pump

 ──────────────────────────────────────────────────続 き Continuing from the front page (72) Inventor Kiyoshi Yukawa 1 Tohocho, Yokkaichi-shi, Mie Japan Process Technology Development Center (72) Inventor Hideki Kato 3-10 Utsudori, Kurashiki-shi, Okayama Pref. In the process development center of Chem Co., Ltd. (72) Yasunori Nakamura 1 Tohocho, Yokkaichi-shi, Mie Japan F-term in the material development center of Polychem Co., Ltd. 4J011 AA05 FB05 FB15 FB19 4J028 AA01A AB00A AB01A AC01A AC10A AC28A AC31A AC41A BA00B BA01B BB00B BB01B BC15B BC16B BC24B BC27B BC28B CA27A CA28A CA30A DA01 DA02 DA03 DA06 DA08 DA09 EA01 EB04 EB05 EB07 EB09 EB10 EC02 FA01 FA02 FA04 GA19 4J100 AA03P AA04Q AA16AQAAQ14

Claims (6)

[Claims] 1. A melting point (Tm) measured by a differential scanning calorimeter (DSC) under the condition that the following (1) to (3) are simultaneously satisfied.
A method for producing a propylene-based random copolymer, characterized by continuously polymerizing a propylene-based random copolymer having a temperature of 115 to 165 ° C. (1) Propylene and other α in the presence of a metallocene catalyst
(2) The polymerization temperature T (° C.) satisfies the following equation: 55 ≦ T ≦ 75 T ≦ 1.42 × Tm-100 (3) Amount of propylene monomer present in the polymerization tank ( W
The ratio Ws / Wp (weight ratio) of the amount of inert solvent (Ws) to p) is 0.02 or less. 2. The ratio Ws / Wp of the amount of inert solvent (Ws) to the amount of propylene monomer (Wp) present in the polymerization tank.
The method for producing a propylene-based random copolymer according to claim 1, wherein (weight ratio) is 0.01 or less. 3. The melting point (T) of a propylene-based random copolymer.
The method for producing a propylene-based random copolymer according to claim 1 or 2, wherein m) is 115 to 135 ° C. 4. The olefin polymerization catalyst according to claim 1, wherein the metallocene catalyst is an olefin polymerization catalyst comprising the following components [A] and [B] and, if necessary, component [C]. A method for producing a propylene-based random copolymer. Component [A] Transition metal compound of Groups 4 to 6 of the periodic table having at least one conjugated five-membered ring ligand Component [B] Ion-exchange layered silicate Component [C] Organoaluminum compound 5. The method for producing a propylene-based random copolymer according to claim 1, wherein the metallocene-based catalyst is a prepolymerized olefin polymerization catalyst. 6. The method according to claim 1, wherein the polymerization is carried out by a bulk polymerization method.
5. The method for producing a propylene-based random polymer according to any one of 5.