JPH069724A - Ethylene copolymer - Google Patents

Abstract

PURPOSE:To obtain an ethylene copolymer having a narrow compositional distribution and improved melt tension, fluidity, heat stability, transparency and mechanical strengths by specifying its density, melt flow rate and flow index. CONSTITUTION:65-99wt.% ethylene is copolymerized with 35-1wt.% 3-20C alpha-olefin in the presence of an olefin polymerization catalyst to obtain a copolymer having a density (d) of 0.880-0.950g/cm<3> and a melt flow rate(MFR) (under a load of 2.16kg at 190 deg.C) of 0.01-200g/10min and satisfying the relationship: Tm<400d-250 (wherein Tm ( deg.C) is the temperature at the highest peak in the endotherm as measured with a differential scanning calorimeter), relationship I (wherein W is the rate of the decane-solubles at room temperature) for MFR <10g/min, relationship II for MFR>10g/min, FI>75XMFR (wherein FI (1/sec) is the flow index which is a shear rate shown when the shear stress of a polymer melt at 190 deg.C is 2.4X10<6>dyn/cm<2>, and MT>2XMFR<-0.65> (wherein MT is the melt tension at 190 deg.C).

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a novel ethylene copolymer, and more specifically, it has a narrow composition distribution, excellent fluidity and high melt tension as compared with conventionally known ethylene copolymers. The present invention also relates to an ethylene-based copolymer having excellent thermal stability.

[0002]

TECHNICAL BACKGROUND OF THE INVENTION Ethylene copolymers are molded by various molding methods and used for various purposes.
These ethylene-based copolymers have different required properties depending on the molding method and application. For example, when an inflation film is to be molded at a high speed, an ethylene copolymer with a high melt tension relative to its molecular weight should be selected to ensure stable high-speed molding without bubble fluctuation or breakage. There must be. Similar properties are needed to prevent sagging or tearing in blow molding or to minimize width reduction in T die molding. In addition, in such extrusion molding,
Good fluidity under high shear during extrusion is important from the standpoints of quality of molded products and reduction of power consumption during molding.

By the way, high-pressure low-density polyethylene has a large melt tension as compared with an ethylene copolymer produced by using a Ziegler type catalyst, and is used for applications such as films and hollow containers. However, the high-pressure low-density polyethylene is inferior in mechanical strength such as tensile strength, tear strength or impact resistance, and also inferior in heat resistance and stress crack resistance.

On the other hand, among Ziegler-type catalysts, the ethylene-based polymer obtained by using a chromium-based catalyst has a relatively high melt tension but a poor thermal stability.
It is considered that this is because the chain end of the ethylene polymer produced by this method is likely to be an unsaturated bond.

Further, among the Ziegler-type catalyst systems, ethylene-based polymers obtained by using titanium-based catalysts are difficult to form terminal unsaturated bonds and have excellent thermal stability.
It has the drawback of low melt tension. Therefore, a method for improving the moldability by improving the melt tension and the expansion ratio (die swell ratio) is proposed in JP-A-56-90810 or JP-A-60-106806. However, in general, an ethylene-based polymer obtained with a titanium-based catalyst, particularly a low-density ethylene-based copolymer, has a wide composition distribution and has a problem that a molded product such as a film is sticky.

Among the Ziegler type catalyst systems, it is known that the ethylene polymer obtained by using the metallocene catalyst system has an advantage that the composition such as a film has a narrow composition distribution and a film or the like is less sticky. However, for example, JP-A-60-35007 describes that an ethylene-based polymer obtained by using a zirconocene compound composed of a cyclopentadienyl derivative as a catalyst contains one terminal unsaturated bond per molecule. However, like the ethylene-based polymer obtained using the above chromium-based catalyst, it is expected that the thermal stability is poor. Further, since the molecular weight distribution is narrow, there is a concern that the fluidity during extrusion molding may be poor. Therefore, if an ethylene polymer having excellent melt tension, high fluidity, narrow composition distribution, and excellent thermal stability appears, its industrial value will be extremely high.

As a result of intensive studies in view of such a situation, the present inventors have found that the density and the melt flow rate (MFR) are in a certain range and that the endothermic curve measured by a differential scanning calorimeter (DSC) is Temperature (Tm (° C.)) and density (d) at maximum peak position, decane soluble component amount ratio (W) and density (d) at room temperature, fluidity index (F
I (1 / sec)) and melt flow rate (MFR), and melt tension (MT) and melt flow rate (MFR) satisfying the respective relationships, ethylene copolymers are excellent in melt tension and fluidity, Further, they have found that the composition distribution is narrow and the thermal stability is excellent, and the present invention has been completed.

[0008]

OBJECT OF THE INVENTION It is an object of the present invention to provide an ethylene copolymer capable of producing a film having excellent moldability, transparency and mechanical strength.

[0009]

SUMMARY OF THE INVENTION The ethylene copolymer according to the present invention is a copolymer of ethylene and an α-olefin having 3 to 20 carbon atoms, and has (i) a density (d) of 0.880 to 0. .950
in the range of g / cm ³ , (ii) 190 ° C, 2.16k
Melt flow rate (MFR) at g load is 0.0
It is in the range of 1 to 200 g / 10 min, and (iii) the temperature (Tm (° C.)) at the maximum peak position in the endothermic curve measured by a differential scanning calorimeter (DSC) and the density (d) are Tm <400 d. The relationship represented by −250 is satisfied, and (iv) the decane-soluble component amount ratio (W) at room temperature and the density (d) are MFR ≦ 10 g.
When / min: W <80 × exp (−100 (d−0.88)) + 0.1 MFR> 10 g / min: W <80 × (MFR-9) ^0.35 × exp (−100 (d− 0.88)) + 0.1, and (v) 190 ° C of the molten polymer.
Fluidity index (FI) defined by the shear rate at which the shear stress reaches 2.4 × 10 ⁶ dyne / cm ²
(1 / second)) and the melt flow rate (MFR) satisfy the relationship represented by FI> 75 × MFR, and (vi) the melt tension (MT) at 190 ° C. and the melt flow rate (MFR) are MT. It is characterized by satisfying the relation of> 2 × MFR ^−0.65 .

[0010]

DETAILED DESCRIPTION OF THE INVENTION The ethylene copolymer according to the present invention will be specifically described below. The ethylene copolymer according to the present invention is a random copolymer of ethylene and an α-olefin having 3 to 20 carbon atoms. In this ethylene-based copolymer, the density (d) was 0.880 to 0.950.
g / cm ³ , preferably 0.885 to 0.940 g / c
m ³ , and more preferably 0.890 to 0.935 g / cm ³ .

In such an ethylene copolymer, the structural unit derived from ethylene is present in an amount of 65 to 99% by weight, preferably 70 to 98% by weight, more preferably 75 to 96% by weight, and carbon. The structural unit derived from the α-olefin of the number 3 to 20 is 1 to 35% by weight, preferably 2
It is desirable to be present in an amount of -30 wt%, more preferably 4-25 wt%.

Α- having 3 to 20 carbon atoms used in the present invention
As olefins, propylene, 1-butene, 1-pentene, 1-hexene, 4-methyl-1-pentene, 1-octene, 1
-Decene, 1-dodecene, 1-tetradecene, 1-hexadecene, 1-octadecene, 1-eicosene and the like can be mentioned.

The ethylene copolymer according to the present invention has a melt flow rate (MFR) of 0.01 to 20.
0 g / 10 minutes, preferably 0.03 to 100 g / 10
Min, more preferably in the range of 0.05 to 50 g / min.

The ethylene copolymer according to the present invention has an intrinsic viscosity ([η]) of 0.5 to 4.5 dl / g, preferably 0.6 to 4.0 dl / g, and more preferably 0.0. 7-3.5
It is preferably in the range of dl / g.

Further, the ethylene copolymer according to the present invention has an intrinsic viscosity ([η]) and a melt flow rate (MF).
R) [η] = K × MFR ^C (where K, C
C value is -0.140 to -0.1.
It is in the range of 80, and is characterized in that the value of C is higher than that of an ethylene copolymer having a similar molecular weight distribution polymerized with a conventional titanium catalyst. In the ethylene-based copolymer of the present invention, K = 1.6 and C = −0.156, whereas
A typical value of the above constants for an ethylene copolymer having a similar molecular weight distribution polymerized with a titanium catalyst is K = 1.
84 and C = -0.194.

The value of the molecular weight distribution (Mw / Mn) defined by the ratio of the weight average molecular weight (Mw) and the number average molecular weight (Mn) of the ethylene copolymer according to the present invention is usually 2.0 to 2.0.
It is 6.0.

The number of unsaturated bonds present in the molecule of the ethylene-based copolymer according to the present invention is 0.5 or less per 1000 carbon atoms, and is 1 per molecule of the polymer.
It is less than the number.

The ethylene-based copolymer according to the present invention has a small number of unsaturated bonds present in the polymer, and therefore it is less likely to undergo a reaction such as crosslinking when heated and melted, and is excellent in thermal stability.

In the ethylene copolymer according to the present invention, the temperature (Tm (° C.)) at the maximum peak position and the density (d) in the endothermic curve measured by a differential scanning calorimeter (DSC) are Tm <400. × d-250 It is preferable that Tm <450 × d-297 is more preferable, Tm <500 × d-344 is more preferable, and Tm <550 × d-391 is particularly preferable.

Such an ethylene-based copolymer has a lower Tm with respect to the density than an ethylene-based copolymer polymerized with a conventional titanium-based catalyst. Is excellent.

In the ethylene copolymer according to the present invention, when the n-decane-soluble component amount fraction (W (% by weight)) and the density (d) at room temperature are MFR ≦ 10 g / min: W < 80 × exp (−100 (d−0.88)) + 0.1, preferably W <60 × exp (−100 (d−0.8)
8)) + 0.1, more preferably W <40 × exp (−100 (d−0.8)
8)) + 0.1 MFR> 10 g / min: W <80 × (MFR-9) ^0.35 × exp (−100 (d−0.88)) + 0.1 is satisfied.

It can be said that such an ethylene copolymer of the present invention has a narrow composition distribution. Further, the ethylene-based copolymer according to the present invention has a flow index (FI (1 / (1 / (1)) defined by the shear rate when the stress at 190 ° C. of the molten polymer reaches 2.4 × 10 ⁶ dyne / cm ^2. Sec)) and the melt flow rate (MFR) satisfy the relationship of FI> 75 × MFR, preferably FI> 80 × MFR, more preferably FI> 85 × MFR.

When an ethylene copolymer having a narrow composition distribution is produced by the conventional technique, the molecular weight distribution is generally narrowed at the same time, so that the fluidity is deteriorated and the FI is reduced. Since the FI and MFR of the ethylene-based copolymer of the present invention satisfy the above relationship, a low stress is maintained up to a high shear rate and the moldability is good.

Further, the ethylene copolymer according to the present invention has a melt tension (MT (g)) and a melt flow rate (MFR) at 190 ° C. of MT> 2.0 × MFR ^−0.65, preferably MT> 2.2 × MFR ^{−0.65, and} more preferably MT> 2.5 × MFR ^−0.65 .

Such an ethylene-based copolymer according to the present invention has a melt tension (M) higher than that of a conventional ethylene-based copolymer.
T) is high and moldability is good. Furthermore, in the ¹³ C-NMR spectrum of the ethylene copolymer according to the present invention, αβ and βγ signals based on the methylene chain between two adjacent tertiary carbon atoms in the copolymer main chain are not observed. . Details of the physical meaning of this result are shown in, for example, JP-A-62-121709, but the ethylene-based copolymer of the present invention is α- which can be copolymerized with ethylene.
It shows that the bonding direction of the olefin is regular.

Such an ethylene-based copolymer according to the present invention has, for example, a bidentate in which two groups selected from (a) a specific indenyl group or a substitution product thereof are bonded via a lower alkylene group. A compound of a transition metal of Group IVB of the periodic table having a ligand or a compound of a transition metal of Group IVB of the periodic table using a specific substituted cyclopentadienyl group as a ligand,
In the presence of an olefin polymerization catalyst formed from (b) an organoaluminum oxy compound, (c) a carrier, and optionally (d) an organoaluminum compound, ethylene and C 3
It can be produced by copolymerizing with .about.20 α-olefin so that the density of the obtained polymer is 0.880 to 0.950 g / cm ³ .

The olefin polymerization catalyst and each catalyst component will be described below. (A) A compound of a transition metal of Group IVB of the periodic table or a specific substitution having a bidentate ligand in which two groups selected from a specific indenyl group or a substituted form thereof are bonded via a lower alkylene group A compound of a transition metal of Group IVB of the periodic table having a cyclopentadienyl group as a ligand (hereinafter sometimes referred to as “component (a)”) is specifically represented by the following formula [I] or It is a transition metal compound represented by [II].

MKL ¹ _X-2 ... [I] (In the formula, M represents a transition metal atom selected from Group IVB of the periodic table, and K and L ¹ represent ligands coordinated to the transition metal atom. The ligand K is a bidentate ligand in which the same or different indenyl groups, substituted indenyl groups or partial water additives thereof are bonded via a lower alkylene group, and the ligand L ¹ has 1 to 1 carbon atoms. 12 hydrocarbon groups, alkoxy groups,
It is an aryloxy group, a halogen atom, a trialkylsilyl group or a hydrogen atom, and X represents the valence of the transition metal atom M. ML ² _X ... [II] (In the formula, M represents a transition metal selected from Group IVB of the periodic table, L ² represents a ligand coordinated to a transition metal atom, and at least two of them are represented. L ² is a substituted cyclopentadienyl group having only 2 to 5 substituents selected from a methyl group and an ethyl group, and the ligand L ² other than the substituted cyclopentadienyl group is a carbon atom. It is a hydrocarbon group, an alkoxy group, an aryloxy group, a halogen atom, a trialkylsilyl group or a hydrogen atom of the formulas 1 to 12, and X represents the valence of the transition metal atom M.) In the above general formula [I], M Represents a transition metal atom selected from Group IVB of the Periodic Table, specifically zirconium, titanium or hafnium, preferably zirconium.

K represents a ligand coordinated to a transition metal atom, and the same or different indenyl group, substituted indenyl group, or partial water additive of indenyl group or substituted indenyl group is bound via a lower alkylene group. Bidentate ligand.

Specifically, an ethylenebisindenyl group,
Ethylene bis (4,5,6,7-tetrahydro-1-indenyl)
Group, ethylenebis (4-methyl-1-indenyl) group, ethylenebis (5-methyl-1-indenyl) group, ethylenebis (6-methyl-1-indenyl) group, ethylenebis (7-methyl-1-) An indenyl) group can be illustrated.

L ¹ represents a hydrocarbon group having 1 to 12 carbon atoms, an alkoxy group, an aryloxy group, a halogen atom, a trialkylsilyl group or a hydrogen atom. As the hydrocarbon group having 1 to 12 carbon atoms, an alkyl group, a cycloalkyl group,
Examples thereof include an aryl group and an aralkyl group,
More specifically, methyl group, ethyl group, n-propyl group,
Alkyl groups such as isopropyl group, n-butyl group, isobutyl group, sec-butyl group, t-butyl group, pentyl group, hexyl group, octyl group, 2-ethylhexyl group and decyl group;
Examples thereof include cycloalkyl groups such as cyclopentyl group and cyclohexyl group; aryl groups such as phenyl group and tolyl group; and aralkyl groups such as benzyl group and neofil group.

Examples of the alkoxy group include methoxy group, ethoxy group, n-propoxy group, isopropoxy group, n-butoxy group, isobutoxy group, sec-butoxy group, t-butoxy group, pentoxy group, hexoxy group, octoxy group and the like. Can be illustrated.

Examples of the aryloxy group include a phenoxy group and the like. Halogen atom is fluorine,
Chlorine, bromine and iodine. Examples of the trialkylsilyl group include a trimethylsilyl group, a triethylsilyl group and a triphenylsilyl group.

Examples of the transition metal compound represented by the general formula [I] include ethylenebis (indenyl) zirconium dichloride, ethylenebis (4-methyl-1-indenyl) zirconium dichloride and ethylenebis (4,5,
6,7-Tetrahydro-1-indenyl) zirconium dichloride, ethylenebis (5-methyl-1-indenyl) zirconium dichloride, ethylenebis (6-methyl-1-indenyl) zirconium dichloride, ethylenebis (7-methyl-1- Indenyl) zirconium dichloride, ethylenebis (4-methyl-1-indenyl) zirconium dibromide, ethylenebis (4-methyl-1-indenyl) zirconium methoxychloride, ethylenebis (4-methyl-1-indenyl) zirconium ethoxy chloride, Ethylenebis (4-methyl-1-indenyl) zirconium butoxycyclolide, ethylenebis (4-methyl-1-indenyl) zirconium methoxide, ethylenebis (4-methyl-1-indenyl) zirconium methyl chloride, ethylenebis (4- Methyl-1-indenyl) zirconium dimethyl, Chirenbisu (4-methyl-1-indenyl) zirconium benzyl chloride, ethylene-bis (4-methyl-1-indenyl) zirconium dibenzyl, ethylenebis (4-methyl
Examples include -1-indenyl) zirconium phenyl chloride and ethylenebis (4-methyl-1-indenyl) zirconium hydride chloride. In the present invention, in the zirconium compound as described above, a transition metal compound in which zirconium metal is replaced with titanium metal or hafnium metal can be used.

Among these transition metal compounds represented by the general formula [I], ethylenebis (indenyl) zirconium dichloride, ethylenebis (4-methyl-1-indenyl) zirconium dichloride, ethylenebis (4,
5,6,7-Tetrahydro-1-indenyl) zirconium dichloride is particularly preferred.

In the above general formula [II], M is the periodic table
A transition metal atom selected from Group IVB is shown, and specifically,
Zirconium, titanium or hafnium, preferably zirconium.

L ² represents a ligand coordinated to the transition metal atom M, and at least two ligands L ² among them have only 2 to 5 substituents selected from a methyl group and an ethyl group.
It is a substituted cyclopentadienyl group having 1 unit, and each ligand may be the same or different. This substituted cyclopentadienyl group is a substituted cyclopentadienyl group having two or more substituents, preferably a cyclopentadienyl group having 2 to 3 substituents, and a disubstituted cyclopentadienyl group. A group is more preferable, and a 1,3-substituted cyclopentadienyl group is particularly preferable. In addition, each substituent may be the same or different.

In the above formula [II], the ligand L ² other than the substituted cyclopentadienyl group coordinated to the transition metal atom M has the same carbon number of 1 as that of L ¹ in the above general formula [I]. ~ 1
2 is a hydrocarbon group, an alkoxy group, an aryloxy group, a halogen atom, a trialkylsilyl group or a hydrogen atom.

Examples of the transition metal compound represented by the general formula [II] include bis (dimethylcyclopentadienyl) zirconium dichloride, bis (diethylcyclopentadienyl) zirconium dichloride, and bis (methylethylcyclopentadienyl). ) Zirconium dichloride Bis (dimethylethylcyclopentadienyl) zirconium dichloride, bis (dimethylcyclopentadienyl) zirconium dibromide, bis (dimethylcyclopentadienyl) zirconium methoxychloride, bis (dimethylcyclopentadienyl) zirconium ethoxy chloride , Bis (dimethylcyclopentadienyl) zirconium butoxycyclolide, bis (dimethylcyclopentadienyl) zirconium diethoxide, bis (dimethylcyclopentadiene Nil) zirconium methyl chloride, bis (dimethylcyclopentadienyl) zirconium dimethyl, bis (dimethylcyclopentadienyl) zirconium benzyl chloride, bis (dimethylcyclopentadienyl) zirconium dibenzyl, bis (dimethylcyclopentadienyl) zirconium Examples thereof include phenyl chloride and bis (dimethylcyclopentadienyl) zirconium hydride chloride. In the above example, the disubstituted cyclopentadienyl ring is 1,
Including 2- and 1,3-substitutions, tri-substitutions are 1,2,3- and 1,
Including 2,4-substitutes. In the present invention, a transition metal compound in which zirconium metal is replaced with titanium metal or hafnium metal in the above zirconium compound can be used.

Among these transition metal compounds represented by the general formula [II], bis (1,3-dimethylcyclopentadienyl) zirconium dichloride and bis (1,3-diethylcyclopentadienyl) zirconium dichloride ,
Bis (1-methyl-3-ethylcyclopentadienyl) zirconium dichloride is particularly preferred.

Next, the organoaluminum oxy compound (b) will be described. The organoaluminum oxy compound (b) (hereinafter sometimes referred to as “component (b)”) used in the present invention may be a conventionally known benzene-soluble aluminoxane, and can be used in JP-A-2- 27
It may be a benzene-insoluble organoaluminum oxy compound as disclosed in Japanese Patent No. 6807.

The aluminoxane as described above can be prepared, for example, by the following method. (1) Compounds containing adsorbed water or salts containing water of crystallization, such as magnesium chloride hydrate, copper sulfate hydrate, aluminum sulfate hydrate, nickel sulfate hydrate, ceric chloride hydrate, etc. A method of recovering a hydrocarbon solution by adding an organoaluminum compound such as trialkylaluminum to the hydrocarbon medium suspension and reacting the same.

(2) A method in which water, ice or steam is directly applied to an organoaluminum compound such as trialkylaluminum in a medium such as benzene, toluene, ethyl ether or tetrahydrofuran to recover it as a hydrocarbon solution.

(3) A method of reacting an organoaluminum compound such as trialkylaluminum with an organotin oxide such as dimethyltin oxide or dibutyltin oxide in a medium such as decane, benzene or toluene.

The aluminoxane may contain a small amount of organic metal component. Alternatively, the solvent or unreacted organoaluminum compound may be removed by distillation from the recovered solution of the aluminoxane, and then redissolved in the solvent.

Specific examples of the organoaluminum compound used for preparing the aluminoxane include trimethylaluminum, triethylaluminum, tripropylaluminum, triisopropylaluminum, and triisopropylaluminum.
n-butyl aluminum, triisobutyl aluminum,
Trisec-butylaluminum, tritert-butylaluminum, tripentylaluminum, trihexylaluminum, trioctylaluminum, tridecylaluminum and other trialkylaluminums; tricyclohexylaluminum, tricyclooctylaluminum and other tricycloalkylaluminums; dimethylaluminum Chloride, diethylaluminum chloride,
Dialkyl aluminum halides such as diethyl aluminum bromide and diisobutyl aluminum chloride;
Dialkyl aluminum hydrides such as diethyl aluminum hydride and diisobutyl aluminum hydride; dialkyl aluminum alkoxides such as dimethyl aluminum methoxide and diethyl aluminum ethoxide; and dialkyl aluminum aryloxides such as diethyl aluminum phenoxide.

Of these, trialkylaluminums and trialkylaluminums are particularly preferred. Further, as the organoaluminum compound represented by the general formula _{(i-C 4 H 9)} x Al y (C 5 H 10) z (x, y, z are each a positive number, the z ≧ 2x) represented by Isoprenylaluminum can also be used.

The above organoaluminum compound is
Used alone or in combination. As the solvent used in the preparation of aluminoxane, aromatic hydrocarbons such as benzene, toluene, xylene, cumene and cymene, aliphatic hydrocarbons such as pentane, hexane, heptane, octane, decane, dodecane, hexadecane and octadecane. Aliphatic hydrocarbons such as hydrogen, cyclopentane, cyclohexane, cyclooctane, and methylcyclopentane, petroleum fractions such as gasoline, kerosene, and light oil, or halogens of the above aromatic hydrocarbons, aliphatic hydrocarbons, and alicyclic hydrocarbons. In particular, hydrocarbon solvents such as chlorinated compounds and brominated compounds are mentioned. In addition, ethers such as ethyl ether and tetrahydrofuran can also be used.
Of these solvents, aromatic hydrocarbons are particularly preferable.

In the benzene-insoluble organoaluminum oxy compound, the Al component dissolved in benzene at 60 ° C. is 10% or less, preferably 5% or less in terms of Al atom.
It is particularly preferably 2% or less and insoluble or hardly soluble in benzene.

The solubility of such an organoaluminum oxy compound in benzene is 10 times that of the organoaluminum oxy compound corresponding to 100 mg of Al.
After suspending in 0 ml of benzene and mixing under stirring at 60 ° C for 6 hours, the solid portion separated on the filter was subjected to filtration at 60 ° C using a jacketed G-5 glass filter while hot. Amount of Al atoms present in all the filtrates after washing 4 times with 50 ml of benzene at ℃ (x
It is determined by measuring (mmol) (x%).

The carrier (c) used in the present invention is an inorganic or organic compound and has a particle size of 10 to 300 μm.
m, preferably 20 to 200 μm, in the form of granules or fine particles are used. Among these, porous oxides are preferable as the inorganic carrier, and specifically, SiO ₂ , Al
₂ O ₃ , MgO, ZrO ₂ , TiO ₂ , B ₂ O ₃ , CaO, Z
nO, BaO, ThO _2, etc. or a mixture thereof, for example, SiO ₂ —MgO, SiO ₂ —Al ₂ O ₃ , SiO ₂ —TiO
₂ , SiO ₂ -V ₂ O ₅ , SiO ₂ -Cr ₂ O ₃ , SiO ₂ -Ti
O ₂ -MgO and the like can be exemplified. Among these S
It is preferable that the main component is at least one component selected from the group consisting of iO ₂ and Al ₂ O ₃ .

The inorganic oxide contains a small amount of Na ₂ C.
O ₃ , K ₂ CO ₃ , CaCO ₃ , MgCO ₃ , Na ₂ SO ₄ ,
Al ₂ (SO ₄ ) ₃ , BaSO ₄ , KNO ₃ , Mg (NO ₃ ) ₂ ,
Carbonate such as Al (NO ₃ ) ₃ , Na ₂ O, K ₂ O, Li ₂ O,
It does not matter if it contains sulfates, nitrates or oxides.

The carrier (c) has different properties depending on its type and production method, but the carrier preferably used in the present invention has a specific surface area of 50 to 1000 m ² / g, preferably 100 to 700 m ² / g. , The pore volume is 0.3-
It is preferably 2.5 cm ² / g. The carrier is, if necessary, 100 to 1000 ° C, preferably 150 to 70 ° C.
It is used after firing at 0 ° C.

Further, examples of the carrier that can be used in the present invention include granular or particulate solids of organic compounds having a particle size of 10 to 300 μm. Examples of these organic compounds include α-C 2 -C 14 such as ethylene, propylene, 1-butene, and 4-methyl-1-pentene.
Examples thereof include (co) polymers containing olefin as a main component, or polymers or copolymers containing vinylcyclohexane or styrene as a main component.

The olefin polymerization catalyst used in the production of the ethylene copolymer according to the present invention is formed from the above-mentioned components (a), (b) and (c), but (d) if necessary. Organoaluminum compounds may be used.

Examples of the (d) organoaluminum compound (hereinafter sometimes referred to as "component (d)") which is used as necessary include, for example, the organoaluminum compounds represented by the following general formula [III]. can do.

R ¹ _n AlX _3-n ... [III] (In the formula, R ¹ represents a hydrocarbon group having 1 to 12 carbon atoms, and X 1
Represents a halogen atom or a hydrogen atom, and n is 1 to 3. In the above general formula [III], R ¹ is a hydrocarbon group having 1 to 12 carbon atoms, such as an alkyl group, a cycloalkyl group or an aryl group, and specifically, a methyl group, an ethyl group, n -Propyl group, isopropyl group, isobutyl group, pentyl group, hexyl group, octyl group, cyclopentyl group, cyclohexyl group, phenyl group, tolyl group and the like.

Specific examples of such an organoaluminum compound include the following compounds. Trialkylaluminums such as trimethylaluminum, triethylaluminum, triisopropylaluminum, triisobutylaluminum, trioctylaluminum, and tri-2-ethylhexylaluminum; alkenylaluminums such as isoprenylaluminum;
Dialkyl aluminum halides such as dimethyl aluminum chloride, diethyl aluminum chloride, diisopropyl aluminum chloride, diisobutyl aluminum chloride, and dimethyl aluminum bromide; methyl aluminum sesquichloride, ethyl aluminum sesquichloride, isopropyl aluminum sesquichloride, butyl aluminum sesquichloride, ethyl aluminum sesquibromide, etc. Alkyl aluminum sesquihalides; alkyl aluminum dihalides such as methyl aluminum dichloride, ethyl aluminum dichloride, isopropyl aluminum dichloride and ethyl aluminum dibromide; alkyl aluminum dihalides such as diethyl aluminum hydride and diisobutyl aluminum hydride. Such as beam hydride.

As the organoaluminum compound (d), a compound represented by the following general formula [IV] can also be used. During ^{_{R 1 n AlY 3-n ...}} [IV] ( wherein, R ¹ represents the same hydrocarbon and R ¹ in the general formula [III], Y is -OR ² group, -OSiR ³ ₃ group, - OA
lR ⁴ ₂ group, -NR ⁵ ₂ group, -SiR ⁶ ₃ group or -N (R ⁷⁾ A
lR ⁸ ₂ group, n is 1 to ² , R ² , R ³ , R ⁴ and R ⁸ are a methyl group, an ethyl group, an isopropyl group, an isobutyl group, a cyclohexyl group, a phenyl group,
⁵ is a hydrogen atom, a methyl group, an ethyl group, an isopropyl group,
It is a phenyl group, a trimethylsilyl group or the like, and R ⁶ and R ⁷ are a methyl group, an ethyl group or the like. ) As such an organoaluminum compound, the following compounds are specifically used.

(1) A compound represented by R ¹ _n Al (OR ² ) _3-n , for example, dimethyl aluminum methoxide, diethyl aluminum ethoxide, diisobutyl aluminum methoxide, etc. (2) R ¹ _n Al (OSiR ³ ₃ ) _3-n , for example Et ₂ Al (OSi Me ₃ ), (iso-Bu) ₂ Al (OSiM
e ₃ ), (iso-Bu) ₂ Al (OSiEt ₃ ), etc .; (3) A compound represented by R ¹ _n Al (OAlR ⁴ ₂ ) _3-n , for example, Et ₂ AlOAiLet ₂ , (iso-Bu) ₂ AlOAl (iso-B
u) _{2 and the} like; (4) compounds represented by R ¹ _n Al (NR ⁵ ₂ ) _3-n , such as Me ₂ AlNEt ₂ , Et ₂ AlNHMe, Me ₂ AlNHEt,
_{Et 2 AlN (SiMe 3) 2} , (iso-Bu) 2 AlN (SiMe 3) 2
(5) A compound represented by R ¹ _n Al (SiR ⁶ ₃ ) _3-n , such as (iso-Bu) ₂ AlSi Me ₃ ; (6) R ¹ _n Al (N (R ⁷ ) AlR ⁸ ₂ ) _3-n , such as Et ₂ AlN (Me) AlEt ₂ , (iso-Bu) ₂ AlN
(Et) Al (iso-Bu) ₂ etc.

Among the organoaluminum compounds represented by the above general formulas [III] and [IV], the general formula R ¹ ₃ Al,
The compounds represented by R ¹ _n Al (OR ² ) _3-n and R ¹ _n Al (OA1R ⁴ ₂ ) _3-n are preferable, and the compound in which R is an isoalkyl group and n = 2 is particularly preferable.

When the ethylene copolymer according to the present invention is produced, it is prepared by bringing the above-mentioned component (a), component (b) and carrier (c) and, if necessary, component (d) into contact with each other. Used catalysts. The contacting order of each component at this time is arbitrarily selected, but preferably, the carrier (c) and the component (b) are mixed and contacted, then the component (a) is mixed and contacted, and if necessary, the component ( d)
Are mixed and contacted.

The contact of each of the above components can be carried out in an inert hydrocarbon solvent. Specific examples of the inert hydrocarbon medium used for preparing the catalyst include propane, butane, pentane, hexane, heptane and octane. Aliphatic hydrocarbons such as decane, dodecane, and kerosene; Alicyclic hydrocarbons such as cyclopentane, cyclohexane, and methylcyclopentane; Aromatic hydrocarbons such as benzene, toluene, xylene; Ethylene chloride, chlorobenzene, dichloromethane, etc. Examples thereof include halogenated hydrocarbons and mixtures thereof.

Component (a), component (b), carrier (c) and
And, if necessary, mixing and contacting the component (d),
Minute (a) is usually 5 × 10 per 1 g of carrier (c).^-6~ 5x
10 ^-FourMol, preferably 10^-Five~ 2 x 10^-FourIn molar amounts
The concentration of component (a) used is about 10^-Four~ 2 x 10^-2
Mol / liter, preferably 2 × 10^-Four-10^-2Mol /
It is in the liter range. Component (b) made of aluminum
Atomic ratio with transition metal in minute (a) (Al / transition metal)
Is usually 10 to 500, preferably 20 to 200
It Aluminum as the component (d) used as necessary
Atom (Al-d) and the aluminum atom of the component (b) (Al-
The atomic ratio (Al-d / Al-b) of b) is usually 0.02 to 3, preferably.
It is preferably in the range of 0.05 to 1.5. Ingredient (a)
Minute (b), carrier (c) and optionally component (d)
The mixing temperature at the time of mixing and contacting is usually -50 to 150 ° C,
The temperature is preferably −20 to 120 ° C., and the contact time is 1 minute to
It is 50 hours, preferably 10 minutes to 25 hours.

The olefin polymerization catalyst obtained as described above contains 5 × 10 ^{−6 to} 5 × 10 ⁻⁴ gram atom of transition metal atoms derived from the component (a), preferably 10 g per 1 g of the carrier (c). ^{-5 to} 2 x 10 ^-4 gram atom, and 10 ^{-3 to} 5 x 10 ^-2 gram atom of aluminum atom derived from the component (b) and the component (d) per 1 g of the carrier (c), It is preferable that the carrier is supported in an amount of 2 × 10 ^{−3 to} 2 × 10 ⁻² gram atom.

The catalyst used for producing the ethylene-based copolymer is prepared by preliminarily preparing an olefin in the presence of the above-mentioned component (a), component (b), carrier (c) and, if necessary, component (d). It may be a prepolymerization catalyst obtained by polymerization. The prepolymerization is carried out by introducing an olefin into an inert hydrocarbon solvent in the presence of the component (a), the component (b), the carrier (c) and, if necessary, the component (d) as described above. You can

As the olefin used in the prepolymerization, ethylene and α-olefin having 3 to 20 carbon atoms, such as propylene, 1-butene, 1-pentene, 4-methyl-1-pentene, 1-hexene, 1-octene, 1-decene, 1
Examples include -dodecene and 1-tetradecene. Among these, ethylene used in the polymerization or a combination of ethylene and an α-olefin is particularly preferable.

In the prepolymerization, the above component (a) is
Usually 10 ^{−6 to} 2 × 10 ⁻² mol / liter, preferably 5
It is used in an amount of × 10 ^-5 to 10 ^-2 mol / liter, and the component (a) is usually 5 × 10 ^{-6 to} 5 × 1 per 1 g of the carrier (c).
It is used in an amount of 0 ^-4 mol, preferably 10 ^-5 to 2 × 10 ^-4 mol. The atomic ratio (Al / transition metal) of aluminum of the component (b) and the transition metal in the component (a) is usually 10 to 5.
00, preferably 20 to 200. The atomic ratio (Al-d) of the aluminum atom (Al-d) of the component (d) and the aluminum atom (Al-b) of the component (b) that are used as necessary.
/ Al-b) is usually 0.02 to 3, preferably 0.05 to
It is in the range of 1.5. The prepolymerization temperature is -20 to 80 ° C,
The temperature is preferably 0 to 60 ° C., and the prepolymerization time is 0.1.
It is about 5 to 100 hours, preferably about 1 to 50 hours.

The prepolymerization catalyst is prepared, for example, as follows. That is, the carrier (c) is suspended in an inert hydrocarbon. Next, an organoaluminum oxy compound (component (b)) is added to this suspension and reacted for a predetermined time. The supernatant is then removed and the solid component obtained is resuspended with an inert hydrocarbon. A transition metal compound (component (a)) is added to this system, and after reacting for a predetermined time, the supernatant liquid is removed to obtain a solid catalyst component. Then, in an inert hydrocarbon containing an organoaluminum compound (component (d)),
The solid catalyst component obtained above is added, and olefin is introduced therein to obtain a prepolymerization catalyst. The olefin polymer produced by the prepolymerization is 0.1 g per 1 g of the carrier (c).
It is desirable that the amount is 1 to 500 g, preferably 0.2 to 300 g, and more preferably 0.5 to 200 g. Further, the prepolymerization catalyst contains the component (a) per 1 g of the carrier (c).
Is supported as a transition metal atom in an amount of about 5 × 10 ^{−6 to} 5 × 10 ⁻⁴ gram atom, preferably 10 ⁻⁵ to 2 × 10 ⁻⁴ gram atom, and is derived from the component (b) and the component (d). The aluminum atom (Al) is 5 to 20 in terms of molar ratio (Al / M) to the transition metal atom (M) derived from the component (a).
It is desirable that the carrier be loaded in an amount of 0, preferably 10 to 150.

The prepolymerization can be carried out batchwise or continuously, and can be carried out under reduced pressure, normal pressure or under pressure. In the prepolymerization,
Intrinsic viscosity [η] measured in decalin of at least 135 ° C. in the presence of hydrogen in the range of 0.2 to 7 dl / g,
It is desirable to produce a prepolymer such that it is preferably 0.5-5 dl / g.

The ethylene copolymer used in the present invention comprises ethylene and an α-olefin having 3 to 20 carbon atoms, such as propylene, 1-, in the presence of the above-mentioned olefin polymerization catalyst or prepolymerization catalyst. Butene, 1-pentene,
1-hexene, 4-methyl-1-pentene, 1-octene, 1-decene, 1-dodecene, 1-tetradecene, 1-hexadecene,
It is obtained by copolymerizing 1-octadecene and 1-eicosene.

In the present invention, the copolymerization of ethylene and α-olefin is carried out in the gas phase or in the slurry liquid phase. In the slurry polymerization, an inert hydrocarbon may be used as the solvent, or the olefin itself may be used as the solvent.

Specific examples of the inert hydrocarbon solvent used in the slurry polymerization include butane, isobutane, pentane, hexane, octane, decane, dodecane, hexadecane, octadecane, and other aliphatic hydrocarbons; cyclopentane, methylcyclopentane. , Cyclohexane,
Alicyclic hydrocarbons such as cyclooctane; aromatic hydrocarbons such as benzene, toluene, xylene; gasoline,
Examples include petroleum fractions such as kerosene and light oil. Of these inert hydrocarbon media, aliphatic hydrocarbons, alicyclic hydrocarbons, petroleum fractions and the like are preferable.

When carrying out the slurry polymerization method or the gas phase polymerization method, the olefin polymerization catalyst or the prepolymerization catalyst as described above is usually used in a concentration of transition metal atoms of 10 ⁻⁸ to 10 ^−. It is desirable to use an amount of ³ gram atom / liter, preferably 10 ⁻⁷ to 10 ⁻⁴ gram atom / liter.

In the main polymerization, the same organoaluminum oxy compound and / or organoaluminum compound (d) as the component (b) may be added. At this time, the atomic ratio (Al / M) between the aluminum atom (Al) derived from the organoaluminum oxy compound and the organoaluminum compound and the transition metal atom (M) derived from the transition metal compound (a) is 5 to 300. , Preferably 10-20
The range is 0, more preferably 15 to 150.

When carrying out the slurry polymerization method, the polymerization temperature is usually in the range of -50 to 100 ° C, preferably 0 to 90 ° C, and when carrying out the gas phase polymerization method, the polymerization temperature is It is usually in the range of 0 to 120 ° C, preferably 20 to 100 ° C.

The polymerization pressure is usually normal pressure to 100 kg /
It is under a pressure condition of cm ² , preferably ² to 50 kg / cm ² , and the polymerization can be carried out in any of batch system, semi-continuous system and continuous system.

It is also possible to carry out the polymerization in two or more stages under different reaction conditions. The ethylene-based copolymer of the present invention, within a range that does not impair the object of the present invention, a weather resistance stabilizer, a heat resistance stabilizer, an antistatic agent, an antislip agent, an antiblocking agent, an antifogging agent, a lubricant, a pigment, Dye, nucleating agent,
Additives such as a plasticizer, an anti-aging agent, a hydrochloric acid absorbent, and an antioxidant may be added if necessary. Further, a small amount of another polymer compound can be blended without departing from the spirit of the present invention.

The ethylene copolymer of the present invention is a film formed by extrusion molding, pipes / tubes formed by extrusion molding,
It can be used for applications such as fibers, containers by blow molding, daily sundries by injection molding, caps, large molded articles by rotational molding.

In the extrusion molding, the ethylene-based copolymer of the present invention is compared with the conventional medium- and low-pressure method ethylene-based copolymers,
The balance between melt tension and fluidity is excellent, and the workability is greatly improved. Further, the extrusion-molded product is excellent in transparency, impact strength, heat sealability, blocking resistance, etc., as compared with the conventional ethylene-based copolymer. The injection molded product has excellent strength properties such as impact strength and environmental stress resistance. It also has excellent low-temperature characteristics.

The ethylene-based copolymer of the present invention can be produced by extrusion film molding, that is, inflation molding, and T-molding.
It is suitable for use as a film obtained by die molding. In extrusion film molding, it is particularly preferably used as a resin for inflation molding film.

Such an inflation-molded film is a standard bag, a heavy bag, a wrap film, a raw lami film, a sugar bag, an oil packaging bag, a water packaging bag, various packaging films for food packaging, and agricultural materials. Used for infusion bags, etc.
It can also be used as a multilayer film by laminating it with a base material such as nylon or polyester.

[0083]

The ethylene-based copolymer of the present invention is excellent in melt tension and fluidity, has a narrow composition distribution, and is excellent in thermal stability. Further, since the balance between melt tension and fluidity is excellent, it is excellent in workability.

Next, the definition and measurement of physical properties used in the present invention
Method and molding method. (1) Granulation of ethylene-based copolymer Powdery ethylene-based copolymer 1 obtained by gas phase polymerization
To 100 parts by weight, tri (2,4-
0.05 weight of di-t-butylphenyl) phosphate
, N-octadecyl-3- (4'hydro as a heat-resistant stabilizer
Oxy-3 ', 5'-di-t-butylphenyl) propionate
1% by weight, calcium stearate as a hydrochloric acid absorber
Is blended in an amount of 0.05 part by weight. After that, Koni made by Haake
Using a Cull-tapered twin-screw extruder at a set temperature of 180 ° C
Melt extrude to prepare granulated pellets. (2) Density Melt flow rate at 190 ° C under 2.16 kg load
Strand obtained at the time of measuring the MFR (MFR) is 120 ° C.
Heat treatment for 1 hour and slowly cooled to room temperature over 1 hour
Then, measure with a density gradient tube. (3) Composition of copolymer¹³ Determined by C-NMR. That is, 10 mmφ
Approximately 200 mg of copolymer powder in 1 ml of sample tube
Of the sample uniformly dissolved in hexachlorobutadiene¹³C
-NMRR spectrum, measurement temperature 120 ℃, measurement frequency
Number 25.05 MHz, spectrum width 1500 Hz, pulse
Measurement conditions with a pulse repetition time of 4.2 sec and a pulse width of 6 μsec
Determined by measuring below. (4) Melt Flow Rate (MFR) Using the pellets of the copolymer, ASTM D12
Condition of 190 ℃, 2.16kg load according to 38-65T
Measured below. (5) Intrinsic viscosity ([η]) It is a value measured at 135 ° C. using a decalin solvent.
That is, about 20 mg of granulated pellets are added to 15 ml of decalin.
And the specific viscosity η in an oil bath at 135 ° C. _spMeasure
To do. Add 5 ml of decalin solvent to this decalin solution.
After dilution with_spTo measure. This dilution
The operation was repeated twice more, and the concentration (C) was extrapolated to 0.
Η of time_spThe value of / C is determined as the intrinsic viscosity.

[Η] = lim (η _sp / C) (C → 0) (6) Molecular weight distribution (Mw / Mn) Waters GPC model ALC-GPC-150C
It was measured by. The measuring conditions are PSK-GMH-HT manufactured by Toyo Soda Co., Ltd. as a column, orthodichlorobenzene (ODCB) solvent, and 140 ° C. (7) Quantification of unsaturated bond The quantification of unsaturated bond was carried out by using ¹³ C-NMR, that is, the signal attributed to other than the double bond, that is, the signal in the range of 10 to 50 ppm, and the signal attributed to the double bond. That is, the area intensity of the signal in the range of 105 to 150 ppm is obtained from the integral curve and is determined from the ratio. (8) Maximum peak temperature (Tm) by DSC The measurement was performed using a DSC-7 type device manufactured by Perkin Elmer. Temperature (Tm) at the maximum peak position on the endothermic curve
Packs about 5 mg of sample in an aluminum pan at 20 ° C / min.
After raising the temperature to 0 ° C and holding at 200 ° C for 5 minutes, 20
It is determined from the endothermic curve when the temperature is lowered to room temperature at ° C / min and then the temperature is raised at 10 ° C / min. (9) Percentage of n-decane-soluble component (W) The amount of n-decane-soluble component of the copolymer was measured to be about 3% for the copolymer.
After adding g to 450 ml of n-decane and dissolving at 145 ° C, 23
It is performed by cooling to ℃, removing the n-decane-insoluble portion by filtration, and recovering the n-decane-soluble portion from the filtrate.

W = weight of n-decane-soluble portion / (weight of n-decane-insoluble portion and soluble portion) × 100% The smaller the amount of soluble components, the narrower the composition distribution. (10) Melt tension (MT) It is determined by measuring the stress when the molten polymer is stretched at a constant rate. That is, using a granulated pellet of the copolymer as a measurement sample, and using an MT measuring machine manufactured by Toyo Seiki Seisaku-sho, resin temperature 190 ° C., extrusion speed 15 mm
/ Min, winding speed 10 to 20 m / min, nozzle diameter 2.09
mmφ and the nozzle length is 8 mm. (11) Fluidity Index (FI) The fluidity index (FI) is defined as the shear rate at which the shear stress at 190 ° C. reaches 2.4 × 10 ⁶ dyne / cm ² . The flow index (FI) was determined by extruding the resin from the capillary while changing the shear rate and measuring the stress at that time. That is, MT
Using a sample similar to the measurement, using a capillary flow characteristic tester manufactured by Toyo Seiki Seisakusho, a resin temperature of 190 ° C. and a shear stress range of 5 × 10 ^{4 to} 3 × 10 ⁶ dyne / cm ² are measured. .

The MFR of the resin to be measured (g / 10 minutes)
Change the diameter of the nozzle (capillary) as follows, and measure. 0.5 mm when MFR> 20 1.0 mm when 20 ≧ MFR> 3 2.0 mm when 3 ≧ MFR> 0.8 3.0 mm when 0.8 ≧ MFR (12) Film processing method 20mmφ ・ L /
D = 28 single screw extruder, 25mmφ die, lip width 0.7mm, single slit air ring
A film having a thickness of 30 μm was extrusion-molded under the conditions of 90 liter / min., Extrusion rate = 9 g / min., Blow ratio = 1.8, take-up speed = 2.4 m / min., And processing temperature = 200 ° C. (13) Film physical property evaluation method (a) Haze (cloudiness): measured according to ASTM-D-1003-61.

(B) Gloss (Gloss): Measured in accordance with JIS Z8741. (C) Film impact strength: Pendulum type film impact tester (film impact tester) manufactured by Toyo Seiki Seisakusho Ltd.
It was measured by.

(D) Blocking force: An inflation film cut into a size of 10 × 20 cm is sandwiched between type papers, sandwiched between glass plates, and a load of 10 kg is applied in an air bath at 50 ° C. for 24 hours. The film was attached to an open jig at a rate of 200 mm / min, the load at this time was set to Ag, and the blocking force F (g / cm) was expressed as F = A / width of test piece.

[0090]

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

[0091]

Example 1 [Preparation of catalyst component] 7.9 kg of silica dried at 250 ° C. for 10 hours was suspended in 121 liter of toluene and then cooled to 0 ° C. Then, a toluene solution of methylaluminoxane (Al = 1.47 mol / liter) 4
1 liter was dropped in 1 hour. At this time, the temperature in the system was kept at 0 ° C. Subsequently, the mixture was reacted at 0 ° C. for 30 minutes, then heated to 95 ° C. over 1.5 hours, and reacted at that temperature for 4 hours. Then, the temperature was lowered to 60 ° C., and the supernatant was removed by the decantation method. The solid component thus obtained was washed twice with toluene and then resuspended with 125 liters of toluene. To this system, 20 liters of a toluene solution of bis (1,3-dimethylcyclopentadienyl) zirconium dichloride (Zr = 28.4 mmol / liter) was added at 30 ° C. for 30 minutes, and further at 30 ° C. for 2 hours. It was made to react. Then, the supernatant was removed and the solid was washed twice with hexane to obtain a solid catalyst containing 4.6 mg of zirconium per 1 g.

[Preparation of prepolymerized catalyst] To 160 liters of hexane containing 16 mol of triisobutylaluminum, 4.3 kg of the solid catalyst obtained above was added to obtain 3
By carrying out a prepolymerization of ethylene at 5 ° C. for 3.5 hours, a prepolymerized catalyst in which 3 g of an ethylene polymer was prepolymerized per 1 g of a solid catalyst was obtained. The intrinsic viscosity [η] of this ethylene polymer was 1.27 dl / g.

[Polymerization] Copolymerization of ethylene and 1-hexene was carried out using a continuous fluidized bed gas phase polymerization apparatus at a total pressure of 20 kg / cm ² -G and a polymerization temperature of 80 ° C. The prepolymerized catalyst prepared above was converted to 0.05 mmo in terms of zirconium atom.
l / hr, triisobutylaluminum 10 mmol
Ethylene, 1-hexene, hydrogen, and nitrogen were continuously supplied in order to maintain a constant gas composition during the polymerization at a rate of 1 / hr / hr (gas composition; 1-hexene / ethylene =
0.018, hydrogen / ethylene = 0.0012, ethylene concentration = 25%). The polymer yield was 5.2 kg / hr.

The details of the analysis results of the obtained polymer are shown in Table 1.
, The density is 0.927 g / cm ³ , and the MFR is
Is 1.0 g / 10 min., The number of unsaturated bonds is 0.062 per 1000 carbon atoms, and is 0.11 per polymer molecule, and the maximum peak temperature of the endothermic curve measured by DSC. (Tm) was 117.8 ° C, and the decane-soluble portion at room temperature was 0.22% by weight.

[0095]

Examples 2 to 6 Using the prepolymerized catalyst prepared in Example 1, various α-olefins shown in Table 1 were used as comonomers to carry out the same polymerization as in Example 1.

The analysis results of the obtained ethylene copolymer are shown in Table 1, and the evaluation results of the blown film are shown in Table 2.

[0097]

Comparative Example 1 A copolymer of ethylene and 4-methyl-1-pentene was produced in a cyclohexane solvent using a MgCl ₂ -supported Ti catalyst.

The analysis results of the obtained ethylene-based copolymer are shown in Table 1, and the evaluation results of the blown film are shown in Table 2. Using the same 4-methyl-1-pentene as a comonomer, the MFR and the density were almost the same. Compared with the results of Example 4, the n-decane soluble portion was large, the Tm was high, and the balance between FI and MT was high. I know that is bad. In addition, the film evaluation results show that the physical properties of haze, impact strength, and blocking resistance are all inferior.

[0099]

Comparative Example 2 A copolymer of ethylene and hexene-1 was produced in a gas phase using a MgCl ₂ supported Ti catalyst.

The analysis results of the ethylene copolymer thus obtained are shown in Table 1, and the evaluation results of the blown film are shown in Table 2. Compared to the results of Example 2 in which the same 1-hexene was used as a comonomer, the MFR and density were almost the same, the n-decane-soluble portion was large, the Tm was high, and the F
It can be seen that the balance between I and MT is poor. In addition, the film evaluation results show that the physical properties of haze, impact strength, and blocking resistance are all inferior.

[0101]

Comparative Example 3 In Example 1, when preparing the catalyst component, bis (3-n-butylcyclopentadienyl) was used as the zirconium compound instead of bis (1,3-dimethylcyclopentadienyl) zirconium dichloride. Using zirconium dichloride, the same reaction as in Example 1 is carried out,
An ethylene-based copolymer was produced.

The analysis results of the obtained ethylene copolymer are shown in Table 1, and the evaluation results of the blown film are shown in Table 2. It can be seen that the moldability (FI, MT) is poor as compared with the results of Example 6 in which the MFR and the density are almost the same.

FIG. 1 shows the relationship between the film impact strength and the blocking force of the ethylene copolymer. In the figure, the circled numbers represent the numbers of the examples, and the diamond-shaped numbers represent the numbers of the comparative examples.

As is apparent from FIG. 1, the ethylene-based copolymer of the present invention was compared with Comparative Example (excluding Comparative Example 3),
It can be seen that the balance between film impact strength and blocking power is very good. In Comparative Example 3, this balance is good, but there is a drawback that MT and FI are low and inflation moldability is very poor.

[0105]

[Table 1]

[0106]

[Table 2]

[0107]

[Table 3]

[Brief description of drawings]

FIG. 1 is a diagram showing a relationship between a film impact strength and a blocking force of an ethylene-based copolymer. In the figure, the circled numbers represent the numbers of the examples, and the diamond-shaped numbers represent the numbers of the comparative examples.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Toshiyuki Tsutsui 6-1-2 Waki, Waki-cho, Kuga-gun, Yamaguchi Mitsui Petrochemical Industry Co., Ltd.

Claims (1)

[Claims] 1. A copolymer of ethylene and an α-olefin having 3 to 20 carbon atoms, wherein (i) density (d) is 0.8.
It is in the range of 80 to 0.950 g / cm ³ , and (ii) 19
The melt flow rate (MFR) at 0 ° C. and a load of 2.16 kg is in the range of 0.01 to 200 g / 10 minutes, and (iii) the temperature at the maximum peak position in the endothermic curve measured by a differential scanning calorimeter (DSC). (Tm
(° C)) and the density (d) satisfy the relationship represented by Tm <400d-250, and (iv) the decane-soluble component amount ratio (W) at room temperature and the density (d) are MFR ≦ 10 g. When / min: W <80 × exp (−100 (d−0.88)) + 0.1 MFR> 10 g / min: W <80 × (MFR-9) ^0.35 × exp (−100 (d− 0.88)) + 0.1, and (v) 190 ° C of the molten polymer.
Fluidity index (FI) defined by the shear rate at which the shear stress reaches 2.4 × 10 ⁶ dyne / cm ²
(1 / second)) and the melt flow rate (MFR) satisfy the relationship represented by FI> 75 × MFR, and (vi) the melt tension (MT) at 190 ° C. and the melt flow rate (MFR) are MT. An ethylene copolymer characterized by satisfying a relationship of> 2 × MFR ^−0.65 .