JP2552400B2 - Method for producing ethylene copolymer - Google Patents

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a method for producing an ethylene / α-olefin copolymer by a solution polymerization method. More specifically, it uses a catalyst prepared from a magnesium compound, a titanium compound and an organoaluminum compound, A temperature of 120-without supplying hydrogen in an inert solvent.
The present invention relates to an improvement in a method of copolymerizing ethylene and an α-olefin at 300 ° C.

[0002]

2. Description of the Related Art A catalyst consisting of a magnesium compound, a titanium compound and an organoaluminum compound is used in an inert solvent at a temperature of 12.
A method is known in which homopolymerization of ethylene or copolymerization of ethylene and an α-olefin is carried out under conditions in which the produced polymer is dissolved at 0 ° C. or higher (Japanese Patent Publication Nos. 46-31330 and 46-46).
-31968, Japanese Patent Publication No. 47-1372). However, the ethylene copolymer produced by these methods has a problem that it has many fish eyes.

On the other hand, in order to solve the above-mentioned problems, a method of carrying out the polymerization under the above-mentioned conditions without using hydrogen (JP-A-64-24814), or using a dialkylzinc as a molecular weight modifier in the absence of hydrogen There has been proposed a method of carrying out polymerization (JP-A-1-172408). However, the ethylene copolymers obtained by these methods are not sufficiently satisfactory from the viewpoint of fisheye reduction. The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a production method capable of obtaining an ethylene-based copolymer that has few fish eyes and is excellent in properties such as transparency.

[0004]

SUMMARY and operation for solving] The present invention, in order to achieve the above object, a magnesium compound, a catalyst obtained from the organoaluminum compound及beauty tetravalent titanium compounds, aliphatic C2-20 Group ethers and carbon number
One selected from the group consisting of 7 to 15 aromatic ethers
In the presence of one or more ether compounds and in the absence of hydrogen
And 120 ° C to 300 ° C in an inert solvent.
Ethylene and α-olefins under conditions where the polymer dissolves
There is provided a method for producing an ethylene copolymer, which comprises performing copolymerization with In addition, ethylene and α-olefin
Dialkyl zinc should also be present during copolymerization
Provided is a method for producing an ethylene copolymer, which comprises performing copolymerization . Hereinafter, the present invention will be described in more detail. In the present invention, the magnesium compound as a polymerization catalyst, a catalyst prepared from an organoaluminum compound及beauty tetravalent titanium compound is used. In this case, the kind of each compound and the method for preparing the catalyst are not particularly limited, but the following can be preferably used.

Magnesium compound Formula (I) MgR ¹ _n X _2-n (I) (wherein R ¹ is an alkyl group having 1 to 18 carbon atoms, an alkoxyl group, a cycloalkyl group, an alkylaryl group, an aryl group, Aryloxy group, aralkyl group or arylalkoxyl group, X represents a halogen atom, and n is 0 ≦ n
Those represented by ≦ 2) can be preferably used.

As the magnesium compound of formula (I),
For example, methyl magnesium chloride, ethyl magnesium chloride, ethyl magnesium bromide, propyl magnesium chloride, isopropyl magnesium chloride, butyl magnesium chloride, alkyl magnesium halides such as butyl magnesium bromide, ethoxy magnesium chloride, ethoxy magnesium bromide, isopropoxy magnesium chloride, butoxy magnesium Alkoxy magnesium halides such as chloride, aryloxy magnesium halides such as phenoxy magnesium chloride, cycloalkyl magnesium halides such as cyclopentyl magnesium chloride, aryl magnesium halides such as phenyl magnesium halide, ethyl phenyl magne Alkyl magnesium halide, diethyl magnesium, such Umukuroraido, dipropyl magnesium, diisopropyl magnesium,
Diisobutyl magnesium, dihexyl magnesium,
Dioctyl magnesium, ethyl methyl magnesium,
Dialkyl magnesium such as ethyl isopropyl magnesium and ethyl-n-butyl magnesium, dialkoxy magnesium such as diethoxy magnesium, diisopropoxy magnesium and dibutoxy magnesium,
Examples thereof include magnesium halides such as anhydrous magnesium chloride and anhydrous magnesium bromide. Among various magnesium compounds represented by the general formula (I), anhydrous magnesium chloride and ethyl-n-butylmagnesium are preferable, and ethyl-n-butylmagnesium is particularly preferable. Incidentally, these various magnesium compounds may be used alone, it may be used in combination of two or more.

Organoaluminum Compounds As organoaluminum compounds, there are various compounds, but usually at least one aluminum-
A compound having a carbon bond can be used, and for example, the following formulas (II), (III), (IV) R ² _3-p AlX _p ... (II) R ² _3-t Al (OR ³ ) X _t ... ( III) R ² ₃ Al ₂ X ₃ (IV) (In the formula, R ² and R ³ represent an alkyl group or an aryl group having 1 to 20 carbon atoms, X is the same as above, and p is 0. , 1 or 2, and t represents 0 or 1.).

Examples of such an organoaluminum compound include diethylaluminum monochloride, diisopropylaluminum monochloride, diisobutylaluminum monochloride, dioctylaluminum monochloride, ethylaluminum dichloride,
Examples thereof include isopropyl aluminum monochloride and ethyl aluminum sesquichloride. Among these, the organoaluminum compound represented by R ² ₃ Al ₂ X ₃ is preferable, and ethylaluminum sesquichloride is particularly preferable.

Tetravalent titanium compound represented by the following formula (V) Ti (OR ⁴ ) m X _4-m (V) (wherein, R ⁴ has 1 to 10 carbon atoms, preferably 1 to 6 carbon atoms)
Represents an alkyl group, a cycloalkyl group, an aryl group or an aralkyl group, and X is the same halogen atom as described above. m is usually 0 or an integer of 1 to 4, but is not necessarily an integer, and is a real number satisfying 0 ≦ m ≦ 4 as an average value of a mixture of various titanium compounds. Compound can be used represented by).

[0010] As before Symbol tetravalent titanium compound, for example, tetramethoxy titanium, tetraethoxy titanium, tetra -n- propoxytitanium, tetraisopropoxytitanium, tetra -n- butoxy, tetraisobutoxy titanium, tetraphenoxy titanium Such as the general formula Ti (O
Tetraalkoxytitanium represented by R ⁴ ) ₄ , titanium tetrahalides such as TiCl ₄ , TiBr ₄ , and TiI ₄ , (CH ₃ O) TiCl ₃ , (C ₂ H ₅ O) TiCl ₃ , and (C ₃ H ₇ O _{) TiCl 3, (n-C} 4 H 9 O) TiCl 3, (C 2 H 5 O) trihalide alkoxy titanium ₃ such _{TiBr, (CH 3 O) 2} TiCl 2, (C 2 H 5 O) 2 _{TiCl 2, (C 3 H 7} O) 2 TiCl 2, (n-C 4 H 9 O) 2 TiCl 2, (C 3 H 7 O) 2 TiBr 2 , etc. dihalogenated titanium, (CH ₃ O) ₃ TiCl _{, (C 2 H 5 O)} 3 TiCl, (C 3 H 7 O) 3 TiCl, (n-C 4 H 9 O) 3 TiCl, (C 2 H 5 O) 3 TiBr like mode Noharoge emissions titanium etc. Is mentioned. Among these, the general formula Ti (O
The tetraalkoxy titanium represented by R ⁴ ) ₄ is preferable, and tetra-n-butoxy titanium is particularly preferable.

[0011] Preparation method polymerization catalyst of the catalyst is prepared from the above magnesium compound and an aluminum compound and a tetravalent titanium compound. There is no particular restriction on the preparation method of the catalyst, for example, may be mixed together and a magnesium compound in the polymerization reaction vessel having a monomer and an organoaluminum compound and a tetravalent titanium compound added separately. As a preferable method for preparing the catalyst, for example, a magnesium compound is reacted with an organoaluminum compound, and the obtained reaction product is mixed with a tetravalent compound .
And a method of mixing a titanium compound.

The method will be described in more detail below. That is, a magnesium compound and an organoaluminum compound are added to an inert solvent, and the temperature is, for example, 0 to
The catalytic reaction is carried out at 240 ° C. for 1 hour or less with stirring, for example. As the inert solvent used in this, for example, aliphatic hydrocarbons having 5 to 16 carbon atoms, alicyclic hydrocarbon, aromatic hydrocarbon, and the like, specifically, normal - or iso - pentane, hexane, heptane, octane, decane, dodecane, tetradecane or cyclo hexane, and further benzene, toluene, and xylene. Further, the ratio of the magnesium compound and the organoaluminum compound added here is not particularly limited, and in short, it may be appropriately adjusted within such a range as to be the ratio of each metal component in the catalyst described later. A reaction product of a magnesium compound and an organoaluminum compound, there is no particular limitation on the mixing of the tetravalent titanium compound. However, upon mixing, the ratio of each metal component in the catalyst is such that the magnesium / titanium ratio (atomic ratio) is within the range of 0.1 to 200, particularly 0.5 to 30, and the aluminum / titanium ratio (atomic ratio). Ratio) from 1 to 20
It is preferably within the range of 0, particularly 2 to 100. When the magnesium / titanium atomic ratio is out of the above range, the activity of the catalyst is lowered. When the aluminum / titanium atomic ratio is less than 1, the activity of the catalyst decreases, and
Even if the titanium atomic ratio is made larger than 200, the catalytic activity corresponding to it may not be obtained.

In the present invention, the amount of the above catalyst used is
The catalyst concentration in the polymerization reaction system is 0,0 as the titanium concentration.
01-10 mmol / l, preferably 0.00
It is preferably about 1 to 0.1 mmol / liter. In the polymerization, a known activator, such as a halide of an element belonging to Group IV of the periodic table, can be coexisted with the catalyst to be used as a polymerization catalyst system.
This can further increase the activity. Examples of the activator include halides of carbon, silicon, germanium, tin, lead and the like, and specifically, for example, methyl chloride, methyl iodide, methylene chloride, isopropyl chloride, -t-chloride. Examples thereof include carbon halides such as butyl and carbon tetrachloride, silicon halides such as tetrachlorosilane, tin halides such as tin tetrachloride, and lead halides such as lead tetrachloride. Among these various halides, carbon halide, n-propyl chloride, isopropyl chloride, n-butyl chloride, isobutyl chloride,
Tert-butyl chloride, sec-butyl chloride and the like can be preferably used. Incidentally, these active agents can be used that singly can also be used in combination of two or more.

[0014] carried out prior to the polymerization, no particular limitation for instructions compounding of the active agent and a polymerization catalyst, for example, (1) a magnesium compound in the polymerization reaction vessel and an aluminum compound and a tetravalent titanium compound and the active agent may be fed separately bets, (2) at the time of catalyst preparation, the magnesium compound, the active agent is the total amount mixed in any of the organomagnesium compound and a tetravalent titanium compound and then, the other components of the catalyst It may be mixed thereto or, alternatively, (3) at the time of catalyst preparation, the magnesium compound, mixing a portion of the active agent in any of the organic aluminum compound and a tetravalent titanium compound and then the catalyst to of the other ingredients when mixed preparation, the magnesium compound may be added the remaining amount of the active agent in any of the organic aluminum compound and a tetravalent titanium compound. Further, the addition amount of the activator is
When the activator / Al molar ratio is a, 0 <a ≦
The range of 5.0, preferably 0.01 ≦ a ≦ 1.0 is desirable.

In the present invention, copolymerization is carried out with the above catalyst ,
Even without least the following is performed in the presence of a type of ether compound. That is, aliphatic ethers having a carbon number of 2-20,
And a group consisting of aromatic ethers having 7 to 15 carbon atoms
At least one ether compound is used selected et. Here, examples of the aliphatic ethers include diethyl ether, di-n-propyl ether, di-iso-propyl ether, di-n-butyltere, di-n-amyl ether, di-iso-amyl ether, and dineo. Pentyl ether, di-n-hexyl ether, di-n-octyl ether, methyl-n-butyl ether, methyl-t-butyl ether, methyl-iso-amyl ether, ethyl-iso-butyl ether, ethyl-n-butyl ether and the like can be mentioned. As an aromatic ether,
Examples include anisole and phenetole. Among these, methyl-t-butyl ether and anisole are particularly preferable.

The means for supplying the ether compound to the polymerization reaction system is not particularly limited, and for example, (1) a method of mixing the catalyst with the catalyst during preparation of the catalyst and (2) supplying the catalyst separately to the polymerization system. Examples of the method include a method of supplying by mixing with any of the components, (3) a method of supplying separately from the catalyst, and the like. From the viewpoint of sufficiently expressing the effect,
It is preferable to supply the polymerization reaction system separately from the catalyst. Book
The supply amount of the ether compound used in the invention needs to be set in consideration of various factors such as the type of the monomer used and the type of the catalyst, but the concentration in the polymerization system is 0.001 to 5 mmol / l. Yes, 0 . 001 to 1m
It is preferably about mol / l.

The method of the present invention is carried out in the presence of the above catalyst and an ether compound without supplying hydrogen to ethylene and α-.
Copolymerization with olefin in an inert solvent at 120 ° C to 3
It is carried out under the condition that the polymer produced at 00 ° C. is dissolved in the solvent . In this case, the α-olefin is not particularly limited as long as it is an α-olefin other than ethylene, but those having 4 to 20 carbon atoms, particularly 4 to 8 carbon atoms can be suitably used. Examples of such α-olefin include butene-
1, pentene-1, 4-methyl-1-pentene, hexene-1, heptene-1, octene-1, decene-1, undecene-1 and the like. Incidentally, alpha-olefins may be used alone, may be used or two or more kinds. The use ratio of ethylene and α-olefin may be selected to any value according to the type and characteristics of the intended ethylene copolymer, but for example, the total of ethylene and α-olefin used is 100 mol. %, Ethylene is usually 60 to 99.85 mol%, preferably 70 to 9
The ethylene copolymer can be preferably produced by setting the concentration in the range of 9.5 mol%.

The inert solvent may have 5 to 1 carbon atoms.
6 include saturated aliphatic hydrogen, alicyclic hydrocarbon, aromatic hydrocarbon and the like. Specific examples include, for example, alkanes such as n-pentane, isopentane, hexane, isohexane, neohexane, heptane, isoheptane, octane, isooctane, nonane, isononane, decane, isodecane, undecane, dodecane, tetradecane, hexadecane; cyclopentane, Examples thereof include cycloalkanes such as cyclohexane, methylcyclohexane, ethylcyclohexane and dimethylcyclohexane; aromatic hydrocarbons such as benzene, toluene, xylene and ethylbenzene. Among these, n-pentane, isopentane, n-hexane, isohexane, n-
Heptane, isoheptane, n-octane, isooctane, n-decane, isodecane, cyclohexane, benzene, toluene, xylene and the like are preferable, and n-hexane is particularly preferable.

In the present invention, the polymerization is carried out without supplying hydrogen as a molecular weight regulator. This is because if hydrogen as a molecular weight modifier is present in the polymerization reaction system, fish eyes frequently occur in the obtained molded product of the copolymer. Therefore , in the present invention, the polymerization catalyst and a specific ether compound are used.
With use of the object, as a molecular weight modifier in place of hydrogen, it may be used dialkylzinc. Examples of the dialkyl zinc include dimethyl zinc, diethyl zinc,
Dipropyl zinc, dibutoxy zinc, methyl ethyl zinc,
Methylpropyl zinc, ethylpropyl zinc and other dialkyl zincs can be used. Among these various dialkylzinc, dialkylzinc having an alkyl group having 1 to 3 carbon atoms is preferable, and diethylzinc is particularly preferable.

In the present invention, it is important to set the reaction temperature for carrying out the polymerization reaction within the range of 120 to 300 ° C. Within this temperature range, the temperature range in which the produced polymer dissolves, for example, 150 to 250 ° C
A temperature range of the order of magnitude is preferred. The reaction pressure is usually 10 to 1
It is suitable to set the pressure to 50 Kg / cm 2 · G, preferably 20 to 90 Kg / cm 2 · G. Further, the average residence time of the polymerization reaction mixture in the polymerization vessel cannot be unconditionally specified because it varies depending on various other conditions such as the type and composition of the catalyst, monomer, solvent, etc. used, the reaction temperature and the like. That is, this average residence time may be appropriately set so that a sufficient conversion rate can be obtained, but as a range that is usually suitably performed, for example, 0.1 to 100.
Minutes, preferably 0.5 to 60 minutes.

[0021]

EXAMPLES The present invention will be specifically described below with reference to Examples and Comparative Examples, but the present invention is not limited to the following Examples. Example 1 In a 1-liter continuous polymerization reaction vessel, dehydrated n-hexane was 7.5 liters / hour, ethylaluminum sesquichloride was 3.3 mmol / hour, ethyl-n-butylmagnesium was 0.83 mmol / hour, and tetra-ethyl was added. Butoxy titanium: 0.17 mmol / hour, methyl-t-butyl ether: 1.65 mmol / hour, ethylene: 7
00g / hour, 1-octene were continuously supplied at 500g / hour, respectively, reaction temperature 185 ° C, reaction pressure 70Kg
The copolymerization reaction was carried out under the condition of / cm 2 · G to obtain 730 g of ethylene-1-octene copolymer. Table 1 shows the polymerization conditions and the polymerization results at this time.

The density, fish eye, and haze in Table 1 were evaluated as follows. Density: Measured according to the density gradient tube method of JIS K7112. Fish eye: Using an extruder having a diameter of 20 mm, a film having a thickness of 25 μm was produced by forming a film under the conditions of a die diameter of 40 mm, a gap of 1 mm and a blow-up ratio of 2.1, and the fish eye was visually evaluated. Haze: The film formed above was measured according to JIS K7105.

Example 2 The same operation as in Example 1 was carried out except that anisole was used instead of methyl-t-butyl ether, and the results shown in Table 1 were obtained. Comparative Example 1 The same operation as in Example 1 was carried out except that the ether compound was not used and the catalyst conditions were changed as shown in Table 1, and the results shown in Table 1 were obtained. Comparative Example 2 The same operation as in Example 1 was carried out except that the ether compound was not used and the catalyst conditions were changed as shown in Table 1, and the results shown in Table 1 were obtained. Examples 3 to 5 The same operations as in Example 1 were carried out except that the catalyst conditions, the amount of diethyl zinc supplied, and the amount of 1-octene were changed so that the MI and the density were predetermined, respectively. The results shown in are obtained. Comparative Examples 3 to 5 The same as Example 1 except that the ether compound was not used and the catalyst conditions, hydrogen / ethylene ratio, and 1-octene amount were changed so that the MI and the density were predetermined. Was carried out and the results shown in Table 1 were obtained.

[0024]

[Table 1]

[0025]

As described above, according to the present invention,
It is possible to obtain an ethylene / α-olefin copolymer having less fish eyes and having improved properties such as transparency.

Continuation of the front page (56) Reference JP-A-1-172408 (JP, A) JP-A 64-24814 (JP, A) JP-A 2-219806 (JP, A) JP-A 63-234003 (JP , A) JP-A-56-30412 (JP, A)

Claims (2)

(57) [Claims] 1. A magnesium compound, using a catalyst obtained from the organoaluminum compound及beauty tetravalent titanium compounds, aliphatic ethers having 2 to 20 carbon atoms and 7 to carbon atoms
One or more selected from the group consisting of 15 aromatic ethers
In the presence of the above ether compound and in the absence of hydrogen,
The product poly at 120 ° C to 300 ° C in an inert solvent.
Of ethylene and α-olefin
A method for producing an ethylene copolymer, which comprises performing copolymerization . 2. At the time of copolymerization of ethylene and α-olefin
The method according to claim 1, wherein the copolymerization is carried out in the presence of dialkylzinc .