JPH04279610A - Production of ethylene copolymer - Google Patents

Abstract

PURPOSE:To obtain the title copolymer with few fisheyes by copolymerization between ethylene and an alpha-olefin under specified conditions with no feed of hydrogen in an inert solvent in the presence of ether compound(s) using a catalyst made up of an Mg compound, organoaluminum compound and Ti compound. CONSTITUTION:Using a catalyst prepared by blending (A) a magnesium compound (e.g. ethyl-n-butylmagnesium), (B) an organoaluminum compound (e.g. ethylaluminum sesquichloride) and (C) a titanium compound (e.g. tetrabutoxytitanium), a copolymerization between ethylene and an alpha-olefin (e.g. 1-octene) is performed in an inert solvent (e.g. n-hexane) without feeding hydrogen in the presence of at least one kind of ether compound (e.g. methyl-t- butyl ether) at 120-300 deg.C and a pressure of 70kg/cm<2>.G, thus obtaining the objective ethylene copolymer (e.g. ethylene-1-octene copolymer).

Description

[Detailed description of the invention]

0001

[Field of Industrial Application] The present invention relates to a method for producing an ethylene/α-olefin copolymer by a solution polymerization method, and more specifically, using a catalyst prepared from a magnesium compound, a titanium compound, and an organoaluminum compound, Temperature 120 ~ without supplying hydrogen in an inert solvent
This invention relates to an improvement in a method for copolymerizing ethylene and α-olefin at 300°C.

0002

[Prior Art and Problems to be Solved by the Invention] 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 ethylene homopolymerization or copolymerization of ethylene and α-olefin is carried out under conditions where the resulting polymer is dissolved at 0°C or higher (Japanese Patent Publication No. 31330/1983).
Japanese Patent Publication No. 46-31968, Japanese Patent Publication No. 47-1372). However, the ethylene copolymers produced by these methods have a problem in that they have many fish eyes.

On the other hand, in order to solve the above problem, a method of conducting polymerization without using hydrogen under the above conditions (
JP-A No. 64-24814) or a method in which dialkylzinc is used as a molecular weight regulator in the absence of hydrogen (Japanese Patent Application Laid-Open No. 1-172408) has been proposed. However, the ethylene copolymers obtained by these methods are not fully satisfactory from the viewpoint of reducing fish eyes. The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a manufacturing method capable of obtaining an ethylene copolymer with fewer fish eyes and excellent properties such as transparency.

0004

[Means and effects for solving the problems] In order to achieve the above object, the present invention uses a catalyst obtained from a magnesium compound, an organoaluminum compound, and a titanium compound, and uses a catalyst obtained from a magnesium compound, an organoaluminum compound, and a titanium compound to provide temperature control without supplying hydrogen in an inert solvent. 120℃
Provided is a method for producing an ethylene copolymer, which comprises copolymerizing ethylene and α-olefin at a temperature of 300° C. to 300° C., the copolymerization being carried out in the presence of at least one ether compound. The present invention will be explained in more detail below. In the present invention, a catalyst prepared from a magnesium compound, an organoaluminium compound, and a titanium compound is used as a polymerization catalyst. In this case, the types of each compound and the method for preparing the catalyst are not particularly limited, but those described below can be suitably used.

Magnesium compound of the following formula (I) MgR1nX2-n
...(I) (However, R1 has 1 to 18 carbon atoms
an alkyl group, an alkoxyl group, a cycloalkyl group, an alkylaryl group, an aryl group, an aryloxy group, an aralkyl group, or an arylalkoxyl group, X represents a halogen atom, and n is 0≦n≦2). can be suitably used.

As the magnesium compound of formula (I),
For example, alkylmagnesium halides such as methylmagnesium chloride, ethylmagnesium chloride, ethylmagnesium bromide, propylmagnesium chloride, isopropylmagnesium chloride, butylmagnesium chloride, butylmagnesium bromide, ethoxymagnesium chloride, ethoxymagnesium bromide, isopropoxymagnesium chloride, butoxymagnesium Alkoxymagnesium halides such as chloride, aryloxymagnesium halides such as phenoxymagnesium chloride, cycloalkylmagnesium halides such as cyclopentylmagnesium chloride, arylmagnesium halides such as phenylmagnesium halide, alkylarylmagnesium halides such as ethylphenylmagnesium chloride, diethylmagnesium, dipropylmagnesium, diisopropylmagnesium,
diisobutylmagnesium, dihexylmagnesium,
Dioctylmagnesium, ethylmethylmagnesium,
Dialkylmagnesiums such as ethylisopropylmagnesium and ethyl-n-butylmagnesium; dialkoxymagnesiums such as diethoxymagnesium, diisopropoxymagnesium, and dibutoxymagnesium;
Examples include magnesium halides such as anhydrous magnesium chloride and anhydrous magnesium bromide. Among the various magnesium compounds represented by the general formula (I), anhydrous magnesium chloride and ethyl-n-butylmagnesium are preferred, and ethyl-n-butylmagnesium is particularly preferred. In addition, these various magnesium compounds may be used individually by 1 type, and can also be used in combination of 2 or more types.

Organoaluminum Compounds There are various compounds as organoaluminum compounds, but usually there is at least one aluminum compound in the molecule.
A compound having a carbon bond can be used, for example, the following formulas (II), (III), (IV) R23-pAlXp
...(II) R23-tAl(OR3)X
t...(III) R23A
l2X3
...(IV) (However, in the formula, R2 and R3 represent an alkyl group or an aryl group having 1 to 20 carbon atoms, X is the same as above, p represents 0, 1 or 2, and t represents 0 or 1).

Examples of such organic aluminum compounds include diethylaluminum monochloride, diisopropylaluminum monochloride, diisobutylaluminum monochloride, dioctylaluminum monochloride, ethylaluminum dichloride,
Examples include isopropylaluminum monochloride and ethylaluminum sesquichloride. Among these, organoaluminum compounds represented by R23Al2X3 are preferred, and ethylaluminum sesquichloride is particularly preferred.

Titanium compound Formula (V) Ti(OR4)m X4-m
...(V) (However, in the formula, R4 represents an alkyl group, a cycloalkyl group, an aryl group, or an aralkyl group having 1 to 10 carbon atoms, preferably 1 to 6 carbon atoms, and X is the same halogen atom as described above. is usually an integer of 0 or 1 to 4, but is not necessarily an integer, but is a real number that satisfies 0≦m≦4 as an average value of a mixture of various titanium compounds. Can be done.

Examples of the titanium compound include tetramethoxytitanium, tetraethoxytitanium, tetra-n
- General formula Ti(OR4)4 of propoxytitanium, tetraisopropoxytitanium, tetra-n-butoxytitanium, tetraisobutoxytitanium, tetraphenoxytitanium, etc.
Tetraalkoxytitanium represented by TiCl4,
Tetrahalogenated titanium such as TiBr4, TiI4,
(CH3O)TiCl3, (C2H5O)TiCl3
, (C3H7O)TiCl3, (n-C4H9O)
Trihalogenated alkoxytitanium such as TiCl3, (C2H5O)TiBr3, (CH3O)2TiCl
2, (C2H5O)2 TiCl2, (C3H7O)
2TiCl2, (n-C4H9O)2TiCl2
, dihalogenated titanium such as (C3H7O)2TiBr2, (CH3O)3TiCl, (C2H5O)3TiCl
, (C3H7O)3 TiCl, (n-C4H9O)3
Examples include monogenized titanium such as TiCl and (C2H5O)3TiBr. Among these, the general formula Ti
Tetraalkoxytitanium represented by (OR4)4 is preferred, and tetra-n-butoxytitanium is particularly preferred.

Method for Preparing Catalyst A polymerization catalyst is prepared from the above-mentioned magnesium compound, aluminum compound, and titanium compound. There are no particular restrictions on the method for preparing the catalyst; for example, a magnesium compound, an organoaluminum compound, and a titanium compound may be separately added to a polymerization reaction vessel containing monomers and then mixed. A preferred method for preparing the catalyst includes, for example, a method in which a magnesium compound and an organoaluminum compound are reacted, and the resulting reaction product is mixed with a titanium compound.

This method will be explained in more detail as follows. That is, a magnesium compound and an organoaluminum compound are added to an inert solvent, and the temperature is, for example, 0 to 0.
The contact reaction is carried out at 240° C., for example, for up to 1 hour, with stirring. In addition, examples of the inert solvent used in this case include aliphatic hydrocarbons having 5 to 16 carbon atoms, alicyclic hydrocarbons, aromatic hydrocarbons, etc. Specifically, normal solvents or iso-pentane , hexane, heptane, octane, decane, dodecane, tetradecane or dichlorohexane, as well as benzene, toluene, xylene and the like. Further, the ratio of the magnesium compound and the organoaluminum compound added here is not particularly limited, and may be appropriately adjusted within a range that provides the ratio of each metal component in the catalyst described later. There are no particular restrictions on mixing the reaction product of the magnesium compound and organoaluminium compound with the titanium compound. However, during mixing, the ratio of each metal component in the catalyst is such that the magnesium/titanium ratio (atomic ratio) is 0.
1 to 200, especially 0.5 to 30, and the aluminum/titanium ratio (atomic ratio) to 1 to 200, especially 2 to 30.
Preferably, it is within the range of 100. If the magnesium/titanium atomic ratio is outside the above range, the activity of the catalyst will decrease. When the aluminum/titanium atomic ratio is less than 1,
The activity of the catalyst decreases, and even if the aluminum/titanium atomic ratio is made larger than 200, a commensurate catalytic activity may not be obtained.

[00013] In the present invention, the amount of the catalyst used is:
The catalyst concentration in the polymerization reaction system is 0.0 as titanium concentration.
01-10 mmol/liter, preferably 0.00
The amount is preferably about 1 to 0.1 mmol/liter. In addition, during polymerization, the catalyst may be further coexisted with a known activator, such as a halide of an element belonging to Group IV of the periodic table, and used as a polymerization catalyst system.
It is also possible to further increase the activity by this. Examples of the above-mentioned activator include halides of carbon, silicon, germanium, tin, lead, etc. Specifically, examples include methyl chloride, methyl iodide, methylene chloride, isopropyl chloride, and t-chloride. Examples 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 halides, n-propyl chloride, isopropyl chloride, n-butyl chloride, isobutyl chloride,
Tert-butyl chloride, sec-butyl chloride, etc. can be suitably used. Note that these activators may be used alone or in combination of two or more.

[0014] There are no particular restrictions on the procedure for blending the activator and polymerization catalyst prior to polymerization; for example, (
1) The magnesium compound, aluminum compound, titanium compound, and activator may be supplied separately into the polymerization reaction vessel, and (2) the activator may be added to any of the magnesium compound, organomagnesium compound, and titanium compound during catalyst preparation. Alternatively, (3) a part of the activator may be mixed with any of the magnesium compound, organoaluminium compound, and titanium compound during catalyst preparation. However, when the other components of the catalyst are then mixed and prepared, the remaining amount of the activator may be added to any of the magnesium compound, organoaluminum compound, and titanium compound. Further, the amount of the activator added is usually 0<a≦5.0, preferably 0.01≦a≦1, where a is the molar ratio of activator/Al.
．． It is desirable to set it in the range of 0.

In the present invention, copolymerization is carried out in the presence of the above catalyst and at least one ether compound. In this case, the type of ether compound is not particularly limited, but aliphatic ethers having 2 to 20 carbon atoms and aromatic ethers having 7 to 15 carbon atoms are preferably used. Here, the above-mentioned aliphatic ethers include diethyl ether, di-n-propyl ether, di-iso-propyl ether, di-
n-butyl ether, di-n-amyl ether, di-is
o-amyl ether, dineopentyl ether, di-n
-hexyl ether, di-n-octyl ether, methyl-n-butyl ether, methyl-t-butyl ether, methyl-iso-amyl ether, ethyl-iso-
Examples include butyl ether and ethyl-n-butyl ether, and examples of aromatic ethers include anisole and phenetol. Among these, methyl-t-butyl ether and anisole are particularly preferred.

There is no particular restriction on the means for supplying the ether compound to the polymerization reaction system, for example, (1) the method of supplying the ether compound by mixing it with the catalyst at the time of preparing the catalyst (
2) When the catalyst is separately supplied to the polymerization system, the catalyst may be mixed with any component thereof, and (3) the catalyst may be supplied separately from the catalyst. From the viewpoint of fully exhibiting the effect, it is preferable to supply it to the polymerization reaction system separately from the catalyst. The amount of the ether compound to be supplied needs to be set in consideration of various factors such as the type of monomer used and the type of catalyst, but the concentration in the polymerization system is 0.001 to 5 mmol/l, preferably 0. ．．
Approximately 0.001 to 1 mmol/l is suitable.

[0017] The method of the present invention is characterized in that ethylene and α-
Perform copolymerization with olefin. 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-olefins include butene-1, pentene-1, 4-methyl-1-pentene, hexene-1, heptene-1, octene-1, decene-1, undecene-1, and the like. In addition, one type of α-olefin may be used alone, or two or more types may be used. The ratio of ethylene and α-olefin used may be selected to any value depending on the type and characteristics of the desired ethylene copolymer, but for example, if the total of ethylene and α-olefin used is 100%
When expressed as mol%, ethylene is usually 60 to 99.85
It is possible to suitably produce an ethylene copolymer by setting the amount in mol%, preferably in the range of 70 to 99.5 mol%.

[0018] In addition, as an inert solvent, a carbon number of 5 to 1 is used.
6 aliphatic saturated hydrogen, alicyclic hydrocarbons, aromatic hydrocarbons, etc. Specific examples include alkanes such as n-pentane, isopentane, hexane, isohexane, neohexane, heptane, isoheptane, octane, isooctane, nonane, isononane, decane, isodecane, undecane, dodecane, tetradecane, hexadecane; cyclopentane; Examples 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, etc. are preferred, and n-hexane is particularly preferred.

In the present invention, polymerization is carried out without supplying hydrogen as a molecular weight regulator. This is because when hydrogen as a molecular weight regulator is present in the polymerization reaction system, fish eyes frequently occur in the resulting copolymer molded product. However, in the present invention, dialkylzinc can be used as a molecular weight regulator instead of hydrogen. As the dialkylzinc, for example, dimethylzinc, diethylzinc, dipropylzinc, dibutoxyzinc, methylethylzinc, methylpropylzinc, ethylpropylzinc, and other dialkylzincs can be used. Among these various dialkylzincs, dialkylzincs in which the alkyl group has 1 to 3 carbon atoms are preferred, and diethylzinc is particularly preferred.

In the present invention, it is important to set the reaction temperature during the polymerization reaction within the range of 120 to 300°C. Within this temperature range, the temperature range where the produced polymer melts, for example, 150 to 250°C
A temperature range of about The reaction pressure is usually 10 to 1
50Kg/cm2・G, preferably 20-90Kg/c
It is preferable to set the value to m2·G. Further, the average residence time of the polymerization reaction mixture in the polymerization container cannot be categorically defined because it varies depending on the type and composition of the catalyst, monomer, solvent, etc. used, and various other conditions such as the reaction temperature. In other words, this average residence time is
The conversion rate may be set appropriately so that a sufficient conversion rate can be obtained, but the range that is usually preferred is, for example, 0.
．． The time is in the range of 1 to 100 minutes, preferably 0.5 to 60 minutes.

[0021]

[Examples] The present invention will be specifically illustrated 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, 7.5 liters/hour of dehydrated n-hexane, 3.3 mmol/hour ethylaluminum sesquichloride, 0.83 mmol/hour ethyl-n-butylmagnesium, and Butoxytitanium 0.17 mmol/hour, methyl-t-butyl ether 1.65 mmol/hour, ethylene 7
00g/hour and 1-octene were continuously supplied at 500g/hour, reaction temperature was 185℃, and reaction pressure was 70K.
A copolymerization reaction was carried out under g/cm2・G conditions, and ethylene-
730 g of 1-octene copolymer was obtained. Table 1 shows the polymerization conditions and polymerization results at this time.

[0022] The density, fish eye, and haze shown in Table 1 were evaluated as follows. Density: Measured according to the density gradient tube method of JIS K7112. Fish eye: using an extrusion molding machine with a diameter of 20 mm, die diameter of 40 mm, gap of 1 mm, blow-up ratio of 2.1
A film with a thickness of 25 μm was produced under the following conditions, and fish eyes were visually evaluated. Haze: The film formed above is JIS K710
Measured according to 5.

Example 2 The same procedure 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 no ether compound was 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 operations as in Example 1 were carried out, except that no ether compound was 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, diethylzinc supply amount, and 1-octene amount were changed so as to achieve predetermined MI and density. The results shown are obtained. Comparative Examples 3 to 5 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 as to achieve the predetermined MI and density. The following operations were carried out, and the results shown in Table 1 were obtained.

[0024]

[Table 1]

[0025]

[Effects of the Invention] As explained above, according to the present invention,
It is possible to obtain an ethylene/α-olefin copolymer with fewer fish eyes and improved properties such as transparency.

Claims (2)

[Claims] Claim 1: Using a catalyst obtained from a magnesium compound, an organoaluminum compound, and a titanium compound, the temperature is 120°C to 3°C in an inert solvent without supplying hydrogen.
A method for producing an ethylene copolymer, the method comprising copolymerizing ethylene and α-olefin at 00°C, the copolymerization being carried out in the presence of at least one ether compound. 2. The method according to claim 1, wherein the copolymerization is carried out in the presence of dialkylzinc.