JPH02276807A - Ethylenic copolymer and production thereof - Google Patents

Abstract

PURPOSE:To obtain an ethylenic copolymer having specific density, intrinsic viscosity, etc., and excellent fluidity and moldability by copolymerizing ethylene and a specific alpha-olefin in the presence of a catalyst composed of a specific hafnium compound, etc., and an organic aluminum-oxy compound. CONSTITUTION:The objective ethylenic copolymer having a density of 0.85-0.92g/cm<3>, an intrinsic viscosity of 0.1-10dl/g (measured in decalin at 35%oC), an Mw/Mn ratio of 1.2-4(Mw and Nn are weight-average molecular weight and number-average molecular weight, respectively, determined by GPC) and a ratio of MFR10/MFR2 of 8-50(MFR10 and MFR2 are melt flow rate measured at 190 deg.C under 10kg load and 2.16kg load, respectively) can be produced by copolymerizing ethylene and a 3-20C alpha-olefin in the presence of a catalyst consisting of (A) a hafnium catalyst component composed of a hafnium compound having a ligand consisting of a polydentate compound having >=2 indenyl groups or their substituents bonded through lower alkylene groups or a compound produced by treating said hafnium compound with an allylsilylated silica gel and (B) an organic aluminum-oxy compound.

Description

DETAILED DESCRIPTION OF THE INVENTION Technical Field of the Invention The present invention relates to a novel ethylene copolymer and a method for producing the same. The present invention relates to a novel ethylene-based copolymer that has excellent polymer fluidity despite having a narrow particle diameter, and a method for producing the same.

Technical Background of the Invention A copolymer of ethylene and an α-olefin having 3 to 20 carbon atoms (hereinafter referred to as an ethylene copolymer) is more difficult to form into a film than conventional high-pressure low-density polyethylene. It has excellent mechanical strength such as tensile strength, tear strength, and impact strength, as well as excellent heat resistance, stress crack resistance, optical properties, heat sealability, etc., and is particularly suitable as a material for blown films.

The above-mentioned ethylene copolymers generally have a ratio of weight average molecular weight (Mw) to number average molecular weight (Mn) (M
The narrower the molecular weight distribution expressed as w/Mn), the better the molded product such as a film obtained from this ethylene copolymer will have, such as less stickiness. However, when the above-mentioned ethylene copolymer has a narrow molecular weight distribution, when this copolymer is melted, 19
MFRlo and 2.16k at 10kg load at 0℃
There were problems in that the fluidity expressed by the ratio to MFR2 at g load (MFR1o/MFR2) was low and the moldability was poor.

Therefore, if an ethylene copolymer with a small My 2 /Mn, a narrow molecular weight distribution, a large MFR1o/MFR2 and excellent fluidity were developed, its industrial value would be extremely large.

Conventionally, olefin polymerization catalysts consisting of titanium or vanadium compounds and organic aluminum compounds have been used to produce ethylene copolymers, but in recent years, zirconium compounds and aluminoxane have been used as new Ziegler-type olefin polymerization catalysts. Catalysts consisting of have recently been proposed.

JP-A No. 58-19309 describes the following formula % formula % [where R is cyclopentadienyl, C1 to CB alkyl, halogen, Me is a transition metal, Ha
g is a halogen] and a transition metal-containing compound represented by the following formula % formula %) [where R is methyl or ethyl and n is 4 to 2
In the presence of a catalyst consisting of a linear aluminoxane represented by the number 0] or a cyclic aluminoxane represented by the following formula [where R and n are the same as above], ethylene and A method is described in which one or more α-refines of C-C1° are polymerized at a temperature of 150°C to 200°C. The publication states that in order to adjust the density of the resulting polyethylene, the polymerization of ethylene should be carried out in the presence of small amounts of up to 10% by weight of somewhat long-chain α-olefins or mixtures. .

JP-A-59-95292 describes a linear aluminoxane represented by the following formula, [where n is 2 to 40, and R is C-C6] and a linear aluminoxane represented by the following formula [where n and R
The definition is the same as above] An invention relating to a method for producing a cyclic aluminoxane represented by The publication states that when olefin polymerization is carried out by mixing, for example, methylaluminoxane and a titanium or zirconium bis(cyclopentagenyl) compound produced by the same production method, It is stated that more than 25 million g of polyethylene can be obtained per hour.

JP-A-60-35005 discloses that an aluminoxane compound represented by the following formula R is R1 or combines to represent 10-] is first reacted with a magnesium compound, and then the reaction product is chlorinated. , and further T l s
The publication discloses a method for producing a polymerization catalyst for olefins by treating with a compound of V s Z r or C. It is described as being particularly suitable for.

JP-A No. 60-35006 discloses mono- or tricyclopentadienyl or its derivative (a) of 21 or more different transition metals and an aluminoxane (b) as a catalyst system for producing a reactor-blended polymer. combinations are disclosed. In Example 1 of the same publication, ethylene and propylene were polymerized using bis(pentamethylcyclopentagenyl)zirconium dimethyl and aluminoxane as catalysts, and the number average molecular weight was 15,300, the weight average molecular weight was 36,400, and 3.4% propylene component
It is disclosed that a polyethylene containing polyethylene was obtained. In Example 2, ethylene and propylene were polymerized using bis(pentamethylcyclopentadienyl)zirconium dichloride, bis(methylcyclopentagenyl)zirconium dichloride, and aluminoxane as catalysts, and the number average molecular weight was 2, 200, weight average molecular weight 1
Number average molecular weight 2 consisting of a toluene soluble portion containing a propylene component of 1.900 and 30 mol% and a toluene insoluble portion containing a propylene component with a number average molecular weight of 3.000 and a weight average molecular weight of 7,400 and 4.8 mol%. ,000
, a blend of polyethylene and ethylene-propylene copolymer having a weight average molecular weight of 8,300 and a propylene component of 7.1 mol % was obtained. Similarly, Example 3
has a molecular weight distribution (Mw /Mn) of 4.57 and a soluble portion of propylene component of 20.6% and a molecular weight distribution of 3.0.
A blend of LLDPE and ethylene-propylene copolymer is described, consisting of an insoluble portion of 4 and a propylene component of 2.9 mol %.

JP-A No. 60-35007 discloses that ethylene alone or together with an α-olefin having 3 or more carbon atoms is used with metallocene and the following formula [where R is an alkyl group having 1 to 5 carbon atoms, and n is 1 a cyclic aluminoxane represented by the following formula % [wherein the definitions of R and n are the same as above]: A method for polymerization in the presence of is described.

According to the description in the same publication, the polymer obtained by this method has an ffi weight average molecular weight of about 500 to about 1.4 million,
and has a molecular weight distribution of 1.5 to 4.0.

In addition, JP-A-60-35008 discloses that copolymerization of polyethylene having a wide molecular weight distribution or ethylene and α-olefin of 03 to C1o is achieved by using a catalyst system containing at least 2i1t of metallocene and aluminoxane. It is described that a combination is produced. The publication states that the above copolymer has a molecular weight distribution (My/Mn) of 2 to
50.

Furthermore, JP-A-61-130314 discloses that polypropylene with a high degree of isotacticity can be obtained by polymerizing propylene in the presence of a catalyst system consisting of a sterically fixed zircon-chelate compound and aluminoxane. Are listed.

Furthermore, j, ^-, Chem, Soc,, 109.6
544 (1987), ethylenebis(indenyl)
When propylene is polymerized in the presence of a catalyst system consisting of hafnium dichloride or its hydride and aluminoxane, high molecular weight isotactic polypropylene is produced, with a molecular weight distribution (Mw/Mn) of 2.1-2.
It is stated that it is 4 and narrow.

On the other hand, Japanese Patent Application Laid-Open No. 63-142005 discloses that M
It is described that stereoblock polypropylene having a y/Vin of 5.0 to 14.9 can be obtained. The propylene obtained here is a rubbery polymer with a short isotactic chain length.

The present inventors have found that if ethylene and an α-olefin having 3 to 20 carbon atoms are copolymerized in the presence of an olefin polymerization catalyst consisting of a specific hafnium compound and an organoaluminumoxy compound, Vlw/Win is small. The present invention was completed by discovering that an ethylene copolymer having a narrow molecular weight distribution, a large MFR1o/MFR2, and excellent fluidity can be obtained.

Purpose of the Invention The present invention aims to solve the above-mentioned problems in the prior art. tX! provides an ethylene-based copolymer that is excellent in The purpose is to provide

Summary of the Invention The ethylene copolymer according to the present invention is an ethylene copolymer consisting of a structural unit (a) derived from ethylene and a structural unit (b) derived from an α-olefin having 3 to 20 carbon atoms. (A) The density of the ethylene copolymer is 0.85 to 0.
(B) Intrinsic viscosity [η] measured in decalin at 135°C
is in the range of 0.1 to 10 dfI/g, and (C) weight average molecular weight (Mw) measured by GPC.
and the number average molecule fl (Mn) (My /Mn
) is in the range of 1.2 to 4, and (D) MFRl at 190°C and 10 kg load.

and the ratio of MFR2 at 2,16 kgR weight (MFR/M
FR2) is in the range of 8 to 50.

In addition, the method for producing an ethylene copolymer according to the present invention comprises (A) coordinating a polydentate compound in which at least two groups selected from indenyl groups or substituted products thereof are bonded via a lower alkylene group; ethylene and a hafnium catalyst component obtained by treating the hafnium compound with alkylsilylated silica gel, and (B) a catalyst formed from an organoaluminumoxy compound. ~
It is characterized in that it is copolymerized with α-olefin No. 20 so that the resulting copolymer has a density of 0.85 to 0.92 g/aa.

DETAILED DESCRIPTION OF THE INVENTION The ethylene copolymer and the method for producing the same according to the present invention will be specifically described below.

An explanatory diagram of the manufacturing process of the ethylene copolymer according to the present invention is shown in FIG.

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 copolymer, the density is 0.85~
0.92r/a! , preferably 0.85 to 0.91 g/
cd, more preferably 0.85 to 0.90 tr/-.

Note that the density is M at 190°C with a load of 2.16 kg.
The strands obtained during FR2 measurement were used for measurement using a density gradient tube. In this ethylene copolymer, the structural unit (a) derived from ethylene is 60 to 96 mol%,
Preferably 65-95 mol%, more preferably 70-9
The structural unit (b), which is present in an amount of 4 mol% and derived from an α-olefin having 3 to 20 carbon atoms, is present in an amount of 4 to 40 mol%.
, preferably 5 to 35 mol%, more preferably 6 to 30
Desirably present in an amount of mol %.

The composition of the copolymer is usually 130-NMH of a sample in which about 200 mg of the copolymer is uniformly dissolved in 1 ml of hexachlorobutadiene in an IC1+s+φ sample tube.
The spectrum of measurement temperature 120'C1 measurement frequency 25
．． 05MIIz, spectral width 150011z.

Pulse repetition time 4.2sec, pulse width 6use
It is determined by measuring under the measurement conditions of c.

The α-olefin having 3 to 20 carbon atoms used in the present invention includes propylene, ■-butene, ■-pentene, ■-
hexene, 4-methyl-1-pentene, ■-octene,
■-Decene, ■-dodecene, 1-tetradecene, ■-hexadecene, l-octadecene, l-eicosene, etc. are used.

Further, the ethylene copolymer according to the present invention has an intrinsic viscosity [η] of 0.1 to 10c measured in decalin at 135°C.
It is desirable that the amount is in the range of 1 g/g, preferably 0.5 to 6 dII/g.

Furthermore, the molecular weight distribution (Mw/Mn) of the ethylene copolymer according to the present invention determined by gel permeation chromatography (GPC) is 1.2 to 4, preferably 1.
．． It is in the range of 4 to 3.5, more preferably 1.5 to 3.0. As described above, the ethylene copolymer according to the present invention has a narrow molecular weight distribution and excellent blocking resistance.

The Mv/Mn value was determined as follows based on "Gel Permeation Chromatography" written by Takeuchi and published by Maruzen.

(1) Using standard polystyrene with a known molecular weight (manufactured by Toyo Soda ■, monodisperse polystyrene), calculate the molecular weight M and its G.
P C (Gel Permeatlon Chrom
atograph) counts and molecular weights M and E
A correlation diagram calibration curve of V (ElutronVolume) is created. The concentration at this time is 0.02% by weight.

(2) Take a GPC chromatograph of the sample using GPC #J determination, calculate the number average molecular weight Mn and weight average molecular weight Mw in terms of polystyrene using the above (1), and calculate My /Mn.
Find the value. Sample preparation conditions and GP
Cl]) J constant conditions are as follows.

[Sample Preparation] (a) Disperse the sample in an Erlenmeyer flask together with 0-dichlorobenzene solvent to a concentration of 0.1% by weight.

(b) Heat the Erlenmeyer flask to 140°C and stir for about 30 minutes to dissolve.

(c) Subject the solution to GPC.

[GP (JIJ constant conditions) It was conducted under the following conditions.

(a) Dressing! Manufactured by fWaters (15 (Ic-^LC/
GPC) (b) Column manufactured by Toyo Soda (GMH type) (c) Sample amount 400 μg (d) Temperature 140°C (e) Flow rate 1 m1/min Furthermore, the ethylene copolymer according to the present invention The ratio of MFR, o to MFR2 at 2.16 kg load (VFR,, /MFR2) is 8 to 5.
0, preferably 8.5-45, more preferably 9-4
It is in the range of 0.

As described above, an ethylene copolymer having MFR/MFR2 in the range of 8 to 50 has extremely good fluidity when the polymer is melted.

On the other hand, conventionally known ethylene copolymers with a Viv/Mn of 1.2 to 4 have a MFR as described above.
1o/MFR2 is in the range of 4 to 7, and the fluidity of the polymer during melting is poor.

As mentioned above, the ethylene copolymer according to the present invention has excellent properties such as a small molecular weight distribution (Mw /Mn) and low stickiness of the molded product, and also has MF
It has a large R/MFR2 and has excellent moldability when melting the polymer O.

The ethylene copolymer according to the present invention as described above comprises (A) a polydentate compound in which at least two groups selected from indenyl groups or substituents thereof are bonded via a lower alkylene group; ethylene and a hafnium catalyst component obtained by treating the hafnium compound with alkylsilylated silica gel, and (B) a catalyst formed from an organoaluminumoxy compound. ~
It can be produced by copolymerizing 20 α-olefins so that the resulting copolymer has a density of 0.85 to 0.92.

The catalyst component [A] used in the present invention has an indenyl group or a substituted product thereof, specifically, at least two groups selected from the group consisting of an indenyl group, a substituted indenyl group, and a partially hydrogenated product thereof. These are hafnium compounds whose ligands are polydentate compounds bonded via alkylene groups, or compounds obtained by treating the hafnium compounds with alkylsilylated silica gel.

The following compounds can be exemplified as the hafnium compound.

Ethylenebis(indenyl)dimethylhafnium, ethylenebis(indenyl)diethylhafnium, ethylenebis(indenyl)diphenylhafnium, ethylenebis(indenyl)methylhafnium monochloride, ethylenebis(indenyl)ethylhafnium monochloride, ethylenebis(indenyl)methyl hafnium monopromide, ethylene bis(indenyl) hafnium compound lide, ethylene bis(indenyl) hafnium compound lide, ethylene bis(4,5,6,7-tetrahydro-1-indenyl) dimethyl hafnium, ethylene bis(4, 5,6,7-tetrahydro-1-indenyl) methyl hafnium monochloride, ethylenebis(4,5,6,7-tetrahydro-1-indenyl)
Hafnium dichloride, ethylene bis(4,5,6,7-titrahydroindenyl) hafnium dichloride, ethylene bis(4-methyl-1-indenyl) hafnium dichloride, ethylene bis(5-methyl-1-indenyl) hafnium dichloride , Ethylenebis(6-methyl-1-indenyl)hafnium dichloride, Ethylenebis(7-methyl-1-indenyl)hafnium dichloride, Ethylenebis(5-methoxy-1-indenyl)hafnium dichloride, Ethylenebis(2,3- dimethyl-1-indenyl) hafnium dichloride, ethylenebis(4,7-dimethyl-l-indenyl)hafnium dichloride, ethylenebis(4,7-simethoxy1-indenyl)
Hafnium dichloride.

The hafnium compound may contain a small amount of zirconium or titanium. At that time, the content is 1% by weight or less, preferably 0.7% by weight or less, more preferably 0.5% by weight or less.

Further, as the hafnium catalyst component according to the present invention, a compound obtained by treating the above hafnium compound with alkylsilylated silica gel can be used. More specifically, the hafnium catalyst component used in the present invention is, for example, a column filled with silica gel obtained by alkylsilylation of a hafnium compound solution prepared by dissolving the above hafnium compound in an organic solvent such as toluene. The hafnium compound solution can be brought into contact with the alkylsilylated silica gel, and the hafnium compound solution flowing out can be used.

As the organic solvent, aromatic hydrocarbons such as toluene, benzene, and xylene are preferably used.

In addition, alkylsilylated silica gel can be obtained by treating silica gel with dimethyldichlorosilane, ethylmethyldichlorosilane, lan, trimethylchlorosilane, trimethylbromosilane, divinyldichlorosilane, diethyldichlorosilane, methylpropyldichlorosilane, etc. The one that can be used will be used. The hafnium concentration of the hafnium compound solution is usually 1x10 to 5x
10-3 mol/1, and alkylsilylated silica gel usually has a concentration of 20 to 5 mol per mmol of hafnium compound.
00g is used. The contact temperature between the hafnium compound solution and the alkylsilylated silica gel is usually 0 to 50°C.
is within the range of

When a hafnium catalyst component obtained by treating the hafnium compound with alkylsilylated silica gel is used as the catalyst component (A), an ethylene copolymer with excellent transparency can be obtained.

The catalyst component [B] used in the method of the present invention is an organoaluminumoxy compound. The general formula (
1) and benzene-soluble aluminoxane represented by the general formula (If). In the aluminoxane, R may be the same or different,
A hydrocarbon group such as a methyl group, an ethyl group, a propyl group, a butyl group, preferably a methyl group or an ethyl group, particularly preferably a methyl group, and m is 2 or more, preferably 5.
is an integer greater than or equal to As a method for producing the aluminoxane, for example, the following method can be exemplified.

(1) Compounds containing adsorbed water, salts containing water of crystallization, such as magnesium chloride hydrate, copper sulfate hydrate, aluminum sulfate hydrate, nickel sulfate hydrate, monochloride
A method of adding trialkylaluminium to a suspension in another hydrocarbon medium such as cerium hydrate and causing a reaction.

(2) A method in which water, steam, or ice is directly applied to trialkylaluminium in a medium such as benzene, toluene, ethyl ether, or tetrahydrofuran.

Note that the aluminoxane may contain a small amount of organometallic component.

Further, examples of the organoaluminumoxy compound used in the present invention include benzene-insoluble organoaluminumoxy compounds.

The benzene-insoluble organoaluminumoxy compound will be explained below.

The benzene-insoluble organoaluminumoxy compound used in the present invention can be prepared by (i) a reaction between an organoaluminum compound and water, or a reaction between an aluminoxane solution, such as a hydrocarbon solution, and water or (i) an active hydrogen-containing compound. obtained by.

This benzene-insoluble organoaluminumoxy compound is estimated to have an alkyloxydialuminum unit represented by the following formula, and is soluble in benzene at 60°C.
The l component is 10% or less, preferably 5% or less, particularly preferably 2% or less in terms of Ag atoms, and is insoluble or poorly soluble in benzene.

The solubility of the organoaluminumoxy compound according to the present invention is determined by suspending the organoaluminumoxy compound corresponding to 100 milligram atoms of Al in 100ml of benzene, mixing at 60°C for 6 hours with stirring, and then adding a jacketed suspension. Filtration was performed while hot at 60°C using a G-5 glass filter, and the solid fraction separated on the filter was washed four times with 50 ml of benzene at 60°C, and the AI present in the entire filtrate was removed. It is determined by determining the amount of atoms present (x mmol) as n1 (X%).

In the above alkyl oxydialuminum unit, RI
Specifically, examples include methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group, pentyl group, hexyl group, octyl group, decyl group, cyclohexyl group, cyclooctyl group, etc. can. Among these, methyl group and ethyl group are preferred, and methyl group is particularly preferred.

In addition to the benzene-insoluble organic aluminum urkyloxyaluminum unit according to the present invention, the formula [where R is the same as above, and R2 is a hydrocarbon group having 1 to 12 carbon atoms, an alkoxy group having 1 to 12 carbon atoms] , an aryloxy group having 6 to 2 o carbon atoms, a hydroxyl group, a halogen, or hydrogen, and R1 and R2 represent mutually different groups]. In that case, an organoaluminumoxy compound containing alkyloxyaluminum in a proportion of 50 mol% or more, particularly preferably 70 mol% or more is preferable.

(i) The organoaluminum compound used in producing such a benzene-insoluble organoaluminum oxy compound is RIX, n (wherein R1 is a hydrocarbon group having 1 to 12 carbon atoms, X is a halogen, an alkoxy group having 1 to 12 carbon atoms, an aryloxy group having 6 to 20 carbon atoms, or hydrogen, where n is 2 to 3).

Specifically, such organic aluminum compounds (i) include trimethylaluminum, triethylaluminum, tripropylaluminum, triisopropylaluminum, tri-n-butylaluminum, tri-5a
Trialkylaluminum such as C-butylaluminum, tritart-butylaluminum, tripentylaluminum, trihexylaluminum, trioctylaluminum, tridecylaluminum, tricyclohexylaluminum, tricyclooctylaluminium, dimethylaluminum chloride, diethylaluminum chloride, diethyl Dialkyl aluminum halides such as 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, dialkyl aluminum alkoxides such as diethyl aluminum phenoxide, etc. is used. Among these organoaluminum compounds, those in which R is an alkyl group and X is a chlorine atom in the general formula are preferred, and trialkylaluminum is particularly preferred.

Furthermore, as the organoaluminum compound (i), isoprenylaluminum represented by the general formula %) can also be used.

The organoaluminum compounds (i) as described above may be used alone or in combination.

In addition, as the active hydrogen-containing compound (i) used in producing the benzene-insoluble aluminum oxy compound according to the present invention, alcohols such as methyl alcohol and ethyl alcohol, diols such as ethylene glycol and hydroquinone, etc. are used. It will be done.

In the present invention, when water is used in preparing the benzene-insoluble organoaluminumoxy compound,
Water can be used by dissolving or dispersing it in a hydrocarbon solvent such as benzene, toluene, or hexane, an ether solvent such as tetrahydrofuran, or an amine solvent such as triethylamine, or in the form of water vapor or ice. Also, as water, magnesium chloride, magnesium sulfate, aluminum sulfate, copper sulfate, nickel sulfate, iron sulfate,
Crystal water of a salt such as cerous chloride, or absorbed water adsorbed to an inorganic compound or polymer such as silica, alumina, or aluminum hydroxide, etc. can also be used.

As mentioned above, the benzene-insoluble organoaluminumoxy compound according to the present invention can be produced by (i) a reaction between an organoaluminum compound and water, or a solution of an aluminoxane, such as a hydrocarbon solution and water, or (i) an active hydrogen-containing Obtained by reaction with a compound. (i) To produce a benzene-insoluble organoaluminumoxy compound from an organoaluminum compound and water, (i) the organoaluminum compound and water are brought into contact with each other in a solvent, such as a hydrocarbon solvent, and at that time, the reaction system The number of organoaluminum atoms dissolved in
Water may be added to the reaction system as follows. In order to obtain a benzene-insoluble organoaluminumoxy compound in this way, it is desirable that (i) 1 mol of the organoaluminum compound be contacted with water in an amount of 1 to 5 mol, preferably 1.5 to 3 mol. .

The reaction to produce the benzene-insoluble organoaluminumoxy compound as described above is carried out in a solvent, for example, a hydrocarbon solvent. , aliphatic hydrocarbons such as isobutane, pentane, hexane, octane, decane, dodecane, hexadecane, and octadecane; alicyclic hydrocarbons such as cyclopentane, cyclooctane, cyclodecane, and cyclododecane; and petroleum distillates such as gasoline, kerosene, and light oil. hydrocarbon solvents, such as min.
Alternatively, halogenated hydrocarbons of the above-mentioned aromatic hydrocarbons, aliphatic hydrocarbons, and alicyclic hydrocarbons, particularly halogenated hydrocarbons such as chlorides and bromides, and ethers such as ethyl ether and tetrahydrofuran can also be used. Among these hydrocarbon media, aromatic hydrocarbons are particularly preferred.

The concentration of the organoaluminum compound in the reaction system is 1X10”-3 to 5 gram atoms/g in terms of aluminum atoms.
It is preferably in the range of 1 x 10-2 to 3 gram atoms/g, and the concentration of water such as crystal water in the reaction system is usually 1 x 10-3 to 20 mol/fl, preferably 1 x
It is desirable that the amount is in the range of 10-2 to 10 mol/g.

At this time, it is desirable that the amount of organic aluminum atoms dissolved in the reaction system is 20% or less, preferably 10% or less, and more preferably 0 to 5% of the total organic aluminum atoms.

(i) To bring the organoaluminum compound into contact with water, specifically, the following procedure may be used.

(1) (i) A method of bringing a hydrocarbon solution of organoaluminum into contact with a hydrocarbon solvent containing water.

(2) (i) A method in which (1) organic aluminum and water vapor are brought into contact, such as by blowing water vapor into a hydrocarbon solution of organic aluminum.

(3) (i) Mixing a hydrocarbon solution of an organoaluminum and a hydrocarbon suspension of an adsorbed water-containing compound or a crystal water-containing compound, and (i) bringing the organoaluminum into contact with the adsorbed water or crystal water. Method.

(4) (i) A method of bringing an organic aluminum hydrocarbon solution into contact with ice.

The above-mentioned (i) contact reaction between the organoaluminum compound and water is usually carried out at -100 to 150°C, preferably -150 to 150°C.
It is carried out at a temperature of 100°C, more preferably -30 to 80°C. The reaction time varies greatly depending on the reaction temperature, but is usually about 1 to 200 hours, preferably about 2 to 100 hours.

The benzene-insoluble organoaluminumoxy compound according to the present invention is mixed with a solution of aluminoxane and water or (i)
In order to produce the active hydrogen-containing compound, the aluminoxane in the aluminoxane solution may be brought into contact with water or (i) the active hydrogen-containing compound.

Note that the aluminoxane solution is prepared by dissolving aluminoxane in a solvent such as the one used to produce the benzene-insoluble organoaluminumoxy compound described above, preferably in an aromatic hydrocarbon such as benzene or toluene. The solution may contain other components as long as they do not adversely affect the reaction between the aluminoxane and water or the active hydrogen-containing compound.

The amount of water or (i) active hydrogen-containing compound used in the catalytic reaction is 0.1 to 5 mol, preferably 0.2 to 3 mol, per gram atom of aluminum in the aluminoxane solution.
Used in molar amounts. The concentration in the reaction system is usually 1 x 10-3 to 5 g atoms/in terms of aluminum atoms.
g is preferably in the range of 1xlO-2 to 3 gram atoms/g, and the concentration of water in the reaction system is usually 2x10-4 to 5 mol/g, preferably 2x10 = ~3 mol/g. It is desirable that the concentration is .

A solution of aluminoxane as above and water or (i
) In order to bring the active hydrogen-containing compound into contact with the active hydrogen-containing compound, the contact reaction between an aluminoxane solution and water may be explained as an example. Specifically, the following procedure may be performed.

(1) A method of bringing a solution of aluminoxane into contact with a hydrocarbon solvent containing water.

(2) A method of bringing the aluminoxane in the aluminoxane solution into contact with the water vapor, such as by blowing water vapor into the aluminoxane solution.

(3) mixing a solution of aluminoxane and a hydrocarbon suspension of an adsorbed water-containing compound or a crystalline water-containing compound;
A method of bringing aluminoxane in a solution of aluminoxane into contact with adsorbed water or water of crystallization.

(4) A method in which a solution of aluminoxane is brought into direct contact with water or ice.

(i) In the case of using an active hydrogen-containing compound, the same procedure as above can be applied.

A solution of aluminoxane as above and water or (i
) The contact reaction with an active hydrogen-containing compound is usually -50 to 1
50°C, preferably 0 to 120°C, more preferably 20 to
It is carried out at a temperature of 100°C. The reaction time varies greatly depending on the reaction temperature, but is usually about 0.5 to 300 hours, preferably about 1 to 150 hours.

The hafnium compound as described above is used in an amount of usually 10-8 to 10-2 gram atoms/fl, preferably 10-7 to 10-3 gram atoms/g as the concentration of the hafnium atoms in the polymerization reaction system. It is desirable that

Further, the above aluminoxane is used in an amount of 10-4 to 10-1 gram atom/fI, preferably 5X10-' to 5X10-2 gram atom/g in terms of aluminum atoms in the reaction system. This is desirable.

Polymerization temperature is -50~150℃, preferably 0~120℃
It is desirable that it be within the range of .

The polymerization of olefins as described above is usually carried out in a gas phase or a liquid phase. In liquid phase polymerization, an inert hydrocarbon may be used as a solvent, or the olefin itself may be used as a solvent.

Hydrocarbon media specifically include butane, isobutane, pentane, hexane, heptane, octane, decane,
Aliphatic hydrocarbons such as dodecane, hexadecane and octadecane, alicyclic hydrocarbons such as cyclopentane, methylcyclopentane, cyclohexane and cyclooctane, aromatic hydrocarbons such as benzene, toluene and xylene, gasoline, kerosene, Petroleum fractions such as light oil are used.

The polymerization pressure is usually normal pressure to 100 kg/cj, preferably normal pressure to 50 kg/cj, and the polymerization can be carried out in any of the batch, semi-continuous and continuous methods. The molecular weight of the polymer can be controlled by hydrogen and/or polymerization temperature.

Effect of the invention The novel ethylene copolymer according to the present invention has Mv /M
Small n, narrow molecular weight distribution, and MFR/MFR
2 is large and has excellent fluidity. Therefore, this ethylene copolymer has excellent processability as well as excellent blocking resistance.

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

Example 1 (Preparation of methylaluminoxane) Polymer Com5un, 29.180 (19
8g) was prepared.

(Synthesis of ethylene bis(indenyl) hafnium dichloride) Bis(indenyl)ethane (Bull, Soc, Chlm,
, 2954 (1967)) 5.4 g and T
Charge 50 ml of HF and heat to -30 to - while stirring.
It was cooled to 40"C. To this, n-Bu Ll (1
, 6M solution) was added dropwise, and then -30"
After stirring at C for 1 hour, bis(indenyl)ethane was anionized by naturally raising the temperature to room temperature. Add THF to another 200 ml glass flask purged with nitrogen.
After charging 60 ml and cooling to below -60°C,
(14 (0.78% by weight of zirconium atoms as a contaminant)
was added gradually. after that,
The temperature was raised to 60°C and stirred for 1 hour. The anionized ligand was added dropwise to the mixture, stirred at 60°C for 2 hours, and then filtered through a glass filter. The filtrate was concentrated to an initial volume of 115 ml at room temperature. This operation precipitates a solid. The precipitated solid was filtered through a glass filter, washed with hexane/ethyl ether, and dried under reduced pressure to obtain ethylene bis(indenyl) hafnium dichloride.

The hafnium compound contained 0.40% by weight of zirconium atoms.

(Polymerization) 950 ml of toluene and 50 ml of 1-octene were added to a 2 g glass flask that had been sufficiently purged with nitrogen, and ethylene gas was further passed through at 16047/I+r.

After raising the temperature of the system to 55°C, 1.88 mmol of methylaluminoxane in terms of aluminum atoms and 7.5X of ethylene bis(indenyl) hafnium dichloride were added.
10-3 mmol was added to initiate polymerization. Polymerization was carried out at 60° C. for 10 minutes under normal pressure while continuously supplying ethylene gas. Polymerization was stopped by adding a small amount of methanol, and the resulting polymerization solution was poured into a large amount of methanol to precipitate the polymer. By drying the precipitated polymer at 130°C for 12 hours under normal pressure, the density was 0.866 g/cm2 and the ethylene content was 8.
1.3 mol%, [η] is 1.71 dff/g, My /Mn is 2.59, and MFR2 is 2.1.
2g/10 minutes, and the ratio of MFR/MFR2 is 13.1
Polymer 23.2sr was obtained.

Example 2 1 g of toluene was charged into a 2ft glass flask that had been sufficiently purged with nitrogen, and a mixed gas of ethylene and propylene (14 ON/hour, 40 g/hour, respectively) was passed through the flask. After raising the temperature of the system to 75°C, 1.88 mmol of methylaluminoxane in terms of aluminum atoms and 7.5×1 ethylene bis(indenyl) hafnium dichloride were added.
0 was added to start polymerization. Polymerization was carried out at 80° C. for 10 minutes under normal pressure while continuously supplying the mixed gas. The subsequent operations were carried out in the same manner as in Example 1, and the density was 0.887 g/CI! , the ethylene content is 84.0 mol%, and [η] is 1.50 dI/g
, My /Mn is 2.50, and MFR2 is 0.
．． 80g/10min, and the ratio of MFR/MFR2 is 12
, 7 was obtained.

Comparative Example 1 Density is 0.87g/-, MFR2 is 2.9g/-
MFR/MFR of a copolymer of ethylene and propylene (synthesized with a catalyst consisting of VOCg3 and aluminum ethyl sesquichloride) with Mv/Mn of 2516.
The ratio of 2 was 5.90.

Example 3 (Preparation of hafnium catalyst) 40 g of dimethylsilylated silica gel (Art, 7719 manufactured by MERCK) degassed for 4 hours at room temperature
was suspended in toluene and packed into a glass column with an inner diameter of 35 mm under a nitrogen atmosphere. Next, 200 ml of the toluene solution of ethylenebis(indenyl)hafnium dichloride (Hf-2.07 mmol/N) prepared in Example 1 was gradually poured into the column. The hafnium solution (Hf' -0.17 mmol/l) eluted by the above operation was used as a catalyst component.

(Polymerization) Polymerization was carried out in the same manner as in Example 1 except that 6.6×10 hafnium atoms and Ligram atoms were used and the polymerization was carried out at 70° C. for 35 minutes. The density was 0.855 g/ai and the ethylene content was 76 .2 mol%, [η] is 1.89 dfI/2, and Mv /Finn is 2.4
8, MFR2 is 1.49g/10min, MF
42.4 g of a colorless and transparent polymer having a R1o/MFR2 ratio of 10.1 was obtained.

Example 4 Polymerization was carried out in the same manner as in Example 2 except that the hafnium catalyst component prepared in Example 3 was used as a /X hfnium atom of 6.6X10 and a Ligram atom, and the density was 0.
883 g/cm2, ethylene content is 83.5 mol%, [η] is 1.61 dD/g, M
y/Mn is 2.54 and MFR2 is 0.73f/
lo minutes, and the ratio of M F Rt o /MFR2 is 1
2.2, 17.0 g of a colorless and transparent polymer was obtained.

Example 5 Polymerization was carried out in the same manner as in Example 1 except that the polymerization temperature was 40°C and the polymerization time was 15 minutes.
The density is 0.868g/- and the ethylene content is 82.
0 mol%, [η] is 1.79 dg/g, and M
y/Mn is 2.81 and MFR2 is 0.90g/
10 minutes, and 20.5 g of polymer with an MFR/MFR2 ratio of 32.0 was obtained.

[Brief explanation of drawings]

FIG. 1 is an explanatory diagram of the manufacturing process of the ethylene copolymer according to the present invention. Agent Patent Attorney Shunichi Suzuki

Claims (1)

[Scope of Claims] 1) A structural unit (a) derived from ethylene and a structural unit (b) derived from an α-olefin having 3 to 20 carbon atoms.
), wherein (A) the ethylene copolymer has a density of 0.85 to 0.92 g/cm
^2, (B) Intrinsic viscosity [η] measured in decalin at 135°C
is in the range of 0.1 to 10 dl/g, (C) Weight average molecular weight measured by GPC (@M@w
) and the number average molecular weight (@M@n) (@M@w/@M
@n) is in the range of 1.2 to 4, (D) MFR_1_ with 10kg load at 190℃
0 and MFR_2 at 2.16 kg load (MFR
An ethylene copolymer characterized in that _1_0/MFR_2) is in the range of 8 to 50. 2) (A) A hafnium compound whose ligand is a polydentate compound in which at least two groups selected from indenyl groups or substituents thereof are bonded via a lower alkylene group, or the hafnium compound is used as an alkylsilyl compound. In the presence of a hafnium catalyst component obtained by treatment with silica gel containing ethylene and a catalyst formed from (B) an organoaluminumoxy compound,
A method for producing an ethylene copolymer, which comprises copolymerizing 20 α-olefins so that the resulting copolymer has a density of 0.85 to 0.92 g/cm^2.