JPH062774B2 - Olefin Polymerization Method - Google Patents

Description

TECHNICAL FIELD The present invention relates to the polymerization or copolymerization of ethylene or α-olefin, and more particularly to a catalyst comprising a novel carrier type titanium component, an organoaluminum compound and an electron donating compound. And a method for polymerizing or copolymerizing ethylene or α-olefin.

2. Description of the Related Art In recent years, a method for increasing the activity of a Ziegler-Natta catalyst has been developed. A catalyst comprising a carrier-type titanium component obtained by the reaction, an organoaluminum compound and an organic acid ester has been proposed, but it cannot be said that the activity and the crystallinity of the produced polymer are still sufficient. As a method of improving the crystallinity of the active polymer and / or the produced polymer, many methods of adding various compounds in the step of co-milling magnesium chloride have been proposed, but they are still insufficient and the improvement thereof is desired. It is rare.

Further, as an example of a method for producing a highly active catalyst, Japanese Patent Laid-Open No. 55-582.
07, JP-A-57-63311 discloses a method of using magnesium chloride produced by halogenating an organomagnesium as a carrier, but the performance of the catalyst is not sufficient.

OBJECT OF THE INVENTION It is an object of the present invention to provide a method for polymerizing ethylene or α-olefin which can produce a highly active and highly stereoregular polymer with high efficiency.

Means for Solving the Problems The present invention is represented by (A) (1) the general formula MgR ₂ (wherein R represents an alkyl, alkenyl, cycloalkyl, or aryl group having 1 to 20 carbon atoms). Reacting an organomagnesium compound with (2) an active hydrogen compound which is an aliphatic alcohol having 1 to 20 carbon atoms (3) an organomagnesium compound represented by (1) in the presence of a halogenated hydrocarbon which is not capable of halogenating Then, (4) titanium tetrachloride (5) a solid reaction product obtained by reacting with an aromatic carboxylic acid ester (B) an organoaluminum compound (C) an electron donor selected from an aromatic carboxylic acid ester or an alkoxysilane In this method, ethylene or α-olefin is polymerized or copolymerized by using a component composed of a polymerizable compound as a catalyst.

(1) General formula-MgR ₂ (wherein R is used in the method of the present invention)
Represents an alkyl, alkenyl, cycloalkyl or aryl group having 1 to 20 carbon atoms), and examples thereof include di-n-butylmagnesium, diethylmagnesium, ethyl-n-butylmagnesium, n-butyl-octylmagnesium. , Dibenzyl magnesium, di-sec-butyl magnesium and the like.

These organomagnesium compounds can be used by themselves, but also with complexes with ethers or amines, or with organometallic compounds of elements such as Al, Zn, B, Si, or aluminum alcoholates. It can also be used in the form of complexes with various metal alcoholates. In particular, the general formula MgR ₂ · nAlR ′ ₃ (where n is 0.01 to 2.5
And R and R ′ are hydrocarbon groups having 1 to 20 carbon atoms, particularly 1 to 12 carbon atoms).

Examples of the active hydrogen compound used as the component (2) include alcohols such as ethyl alcohol, iso-propanol, n-butanol, 2-ethylhexanol, and n-decanol.

(1) An organomagnesium compound used as a component and (2)
The addition ratio with the active hydrogen compound used as a component is
It is preferable to select a ratio in which the reaction product obtained by the reaction has substantially no reducing ability. That is, the active hydrogen compound is added in an amount of 2 mol or more, and particularly preferably 2 to 10 mol per 1 g of Mg atom of the organomagnesium compound.

As the halogenated hydrocarbon represented by (3), a halogenated hydrocarbon having substantially no ability to halogenate the organomagnesium compound represented by the formula (1) is used under treatment conditions. A halogenated hydrocarbon that has practically no halogenation ability is
It shows that even if the components (1) and (2) are mixed, only 0.5 mol or less, preferably 0.1 mol or less, per 1 mol atom of magnesium is halogenated and substantially no precipitate is formed.

Examples of such halogenated hydrocarbons include n-butyl chloride, n-hexyl chloride, n-octyl chloride, 1,2-dichloroethane, methylene chloride, sec-butyl chloride, chlorobenzene, bromobenzene and iodobenzene. it can.

On the other hand, when a halogenated hydrocarbon having the ability to halogenate the organomagnesium compound represented by the formula (1) like carbon tetrachloride is used, a precipitate that seems to be magnesium chloride is produced, which is completely different from the present invention. And the catalytic performance is significantly inferior to that of the present invention.

The amount of the halogenated hydrocarbon having substantially no halogenating ability is not particularly limited, but it is preferably 1 to 10,000 g, and particularly preferably 1 to 1000 g per gram of the organomagnesium compound. Also, the reaction temperature is not particularly limited, either.
The temperature is 70 to 300 ° C, preferably -50 to 200 ° C.

Titanium tetrachloride is used as the component (4).

(5) component is an aromatic carboxylic acid ester such as ethyl benzoate, methyl toluate, ethyl toluate, isobutyl phthalate, etc. is used at least as the organoaluminum compound which is the component (B) used in the method of the present invention A compound having one Al-carbon bond in the molecule can be used, for example, a compound represented by the general formula R ¹ _m 1Al (OR ² ) _n HpXq (wherein R ¹ and R ² have 1 to 1 carbon atoms).
Two hydrocarbon groups, X is a halogen atom, and m is 0 <m ≦
3, n is 0 ≦ n <3, p is 0 ≦ p <3, and q is 0 ≦ q <3
And m + n + p + q = 3) is used. Examples of the compound represented by the above general formula include trimethyl aluminum, triethyl aluminum, triisobutyl aluminum, triisopropyl aluminum, diethyl aluminum ethoxide, diethyl aluminum chloride, diisobutyl aluminum chloride, diethyl aluminum bromide, diethyl aluminum iodide, diethyl aluminum. Fluoride, ethyl aluminum sesquichloride, ethyl aluminum dichloride, diethyl aluminum hydride and the like can be mentioned.

The _{(C 2 H 5) 2 Al} -O-Al (C 2 H 5) 2, (C 2 H 5) 2 Al) NAl
(C ₂ H ₅ ) _2, such as an organoaluminum compound in which two or more aluminum atoms are bound to each other through an oxygen atom or a nitrogen atom, LiAl (C
₂ H ₅ ) ₄ etc. are also used.

Among these, the method using a trialkylaluminum or a mixture of a trialkylaluminum and an alkylaluminum halide is preferable.

In the method of the present invention, the use ratio of the component (A) and the component (B) can be varied within a wide range, but in general, the component (B) is 1 to 500 mmol, preferably 0.001 gram atom of titanium contained in the component (A), preferably Is in the range of 3 to 300 mmol. The component (B) may be added in the whole amount at the start of the polymerization, but it is preferable to add it in small amounts intermittently or continuously during the polymerization because the polymerization activity is less lowered. Further, in the case of multi-tank continuous polymerization, it is preferable to add each tank or a part of them separately.

As the electron-donating compound which is the component (C) used in the method of the present invention, ethyl benzoate, methyl toluate, ethyl toluate, aromatic carboxylic acid esters such as isobutyl phthalate, tetraethoxysilane, diphenyldiethoxysilane, Alkoxysilanes such as phenyltriethoxysilane and tetraphenoxysilane are used. Also, two or more of these electron donors may be used in combination.

The amount of the component (C) used depends on the amount of the component (B) used, the amount of the component (A) used, the Ti content, and the polymerization temperature and other polymerization conditions, but is generally used as the component (B). The amount is 5 mol or less, preferably 2 mol or less, and more preferably 1 mol or less, per 1 mol of the aluminum compound.

As the addition method of the component (C), the whole amount may be added at the start of the polymerization, or intermittently or continuously during the polymerization.

In the case of multi-tank continuous polymerization, it may be added to each tank at an arbitrary ratio.

The method of the present invention can be carried out with ethylene, or with the general formula R-CH = CH.
₂ (however, R represents a hydrocarbon residue having 1 to 10 carbon atoms)
Is used for the polymerization or copolymerization of the α-olefin represented by the formula (3), and examples of the α-olefin include propylene, butene-1, hexene-1, 4-methyl, pentene-1, octene-1 and the like. Regarding the copolymerization method, any method such as random copolymerization or block copolymerization can be carried out, and the copolymerization can be carried out at an arbitrary ratio, and at the time of the copolymerization, it can be further copolymerized with a diene.

The polymerization reaction according to the method of the present invention can employ the conventional methods and conditions generally used in the art. At that time, the polymerization temperature is 20 to 300 ° C., preferably 40 to 250 ° C., and the polymerization pressure is 1 to 200 Kg / cm ² abs, preferably 1 to 100 Kg / cm ² abs.

The polymerization reaction can be generally carried out by a slurry method or a solution method using an aliphatic, alicyclic, aromatic hydrocarbon, or a mixture thereof as a dispersant or a solvent, and as the hydrocarbon, propane or butane can be used. , Pentane, hexane,
Heptane, cyclohexane, kerosene, benzene, toluene, etc. are common.

In addition, a bulk polymerization method using a liquid monomer itself as a dispersant or a solvent, and a condition in which a solvent does not substantially exist,
That is, it can be carried out by a so-called gas phase polymerization method in which a gaseous monomer and a catalyst are brought into contact with each other, and can be carried out in any of a batch method, a semi-continuous method and a continuous method.

Further, it is possible to carry out the polymerization separately in two or more stages having different temperatures and hydrogen concentrations, or to combine two or more polymerization methods such as a combination of bulk polymerization and gas phase polymerization.

The molecular weight of the polymer produced in the method of the present invention varies depending on the reaction mode, catalyst system and polymerization conditions, but can be controlled by addition of hydrogen, alkyl halide, dialkyl zinc, etc., if necessary.

Example 1 In a 300 ml round bottom flask, 100 ml of n-butyl chloride, E
t · BuMg · 0.03AlEt ₃ (20% heptane solution) 50 mM added in a nitrogen atmosphere. This mixture is colorless and transparent.

Next, from the dropping funnel, 200 mM ethyl alcohol and n
A mixture of 50 ml of butyl chloride was added dropwise over 15 minutes at room temperature and a precipitate formed. After removing the supernatant, 100 ml of titanium tetrachloride and 0.30 ml of ethyl benzoate were added and reacted at 100 ° C. for 1 hour.

After standing still, remove the supernatant and add 100 ml of titanium tetrachloride to add 1
After reacting for a time, it was washed with 200 ml of n-heptane seven times to obtain the component (A) of the present invention. When a part of this (A) component slurry was taken and dried under reduced pressure, the Ti content was 2.
It was 3 wt%.

N-heptane 50m in a 6l SUS autoclave purged with nitrogen
l, 0.02 g of the component (A), 0.08 m of triethylaluminum
1, diethyl aluminum monochloride 0.17 ml and methyl toluate 0.06 ml were charged in a nitrogen stream. After replacing the gas phase of the autoclave with propylene, 2 kg of liquefied propylene and 1.3 Nl of hydrogen were added.

10 minutes after heating the autoclave, the internal temperature of the autoclave was raised to 75 ° C., and polymerization was carried out at the same temperature for 3 hours.

After completion of the polymerization, unreacted propylene was purged, the contents were taken out and dried at 60 ° C. for 24 hours to obtain 705 g of polypropylene powder.

The intrinsic viscosity of the obtained polypropylene was 1.67 dl / g (135
℃, tetralin), boiling n-heptane extraction residue 95.8%
(Hereinafter abbreviated as II), the bulk specific gravity was 0.35 g / ml.

Example 2 The amount of polypropylene obtained in this polymerization reaction was 23.5 Kg / g-ca.
t was 1022 Kg / g-Ti.

A component (A) having a Ti content of 3.38 wt% was obtained in exactly the same manner as in the method of Example 1, except that 1.5 ml of diisobutyl phthalate was used instead of ethyl benzoate when the component (A) was prepared.

Obtained component (A) 0.02 g, triethylaluminum 0.08 ml
(0.58mM), phenyltrimethoxysilane 0.03ml (0.16m
The same polymerization as in Example 1 was repeated using M) as the catalyst component. The results obtained are shown in the table.

Comparative Examples 1-2 In the method of Example 2, n was replaced with n-butyl chloride.
-Preparation and polymerization of the component A was repeated exactly the same, except that heptane or toluene was used. According to the experimental results, Comparative Examples 1 and 2 have much lower activity and II than Example 2, and it is clear that the use of the component (A) (2) in Example is extremely effective.

Comparative Example 3 300 ml round bottom flask Et under a nitrogen atmosphere put carbon tetrachloride 100ml of (n-Bu) Mg · 0.03AlEt 3 50mM (20% n- heptane solution) was added dropwise I or 15 minutes at room temperatureゝ. At this time, a pale brown precipitate was formed in the reaction product, which was completely different from that in Example 1.

Further, after the reaction with elti alcohol, the same procedure as in Example 2 was carried out to obtain the component (A). Example 2 using this component (A)
The results of the polymerization carried out under the conditions of are shown in the table.

In this case as well, the activity and II were lower than those in Example 2, clearly indicating the effect of the present invention.

[Brief description of drawings]

FIG. 1 is a flow chart of catalyst production to help understanding of the catalyst production process.

Claims (1)

[Claims] 1. An organic manesium compound represented by (A) (1) a general formula MgR ₂ (wherein R represents an alkyl, alkenyl, cycloalkyl and aryl group having 1 to 20 carbon atoms) and (2) carbon (3) An active hydrogen compound, which is an aliphatic alcohol, is reacted with (3) an organomagnesium compound represented by (1) in the presence of a halogenated hydrocarbon having no ability to halogenate, and then (4) Titanium chloride (5) Solid reaction product obtained by reacting with aromatic carboxylic acid ester (B) Organoaluminum compound (C) Component consisting of aromatic carboxylic acid ester or electron donating compound selected from alkoxysilane A method for polymerizing ethylene or α-olefin, which comprises using a catalyst.