JPS6079018A - Ethylene polymerization method - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention] The present invention relates to a high temperature and high pressure polymerization method for ethylene.

A method is known in which ethylene is polymerized in the presence of a Ziegler type catalyst at a temperature of -125° C. or higher and a pressure of 20 kg/- or higher. As for the above catalyst.

Titanium component 9 For example, a combination of a titanium compound supported by titanium trichloride and a magnesium compound and an organoaluminum compound has been proposed (for example,
No. 9-97087, No. 56-18607, No. 57-1
No. 90009).

Since all the titanium components used in the proposed method are solid, they have the following problems.

The solid titanium component must be fed to the polymerization reactor maintained at high pressure as a slurry in a medium of appropriate viscosity and specific gravity. However, it is difficult in itself to prepare a uniform slurry of titanium components, and even if a uniform slurry can be prepared, the solid titanium component tends to settle in the transport pipe, and the titanium component cannot be quantitatively transferred to the polymerization reactor. It is extremely difficult to supply. Unless the amount of titanium component supplied to the polymerization reactor is constant, the stability of the polymerization reaction will be lost. In particular, if the titanium component is supplied in excess, the monopolymerization reaction will run out of control, resulting in an extremely dangerous situation.

High temperature of ethylene using Ziegler type catalyst 11, Φ
In case of ;1...is it a high catalyst? It is desired to develop a liquid titanium component having a value of 1.

The present invention satisfies the above needs.

That is, the present invention uses ethylene or a mixture of ethylene and an α-olefin having at least the number of carbon atoms.

[A] Magnesium nanthenate.

Formula xmTi(oR+)4-m (in the formula + X' represents a chlorine atom, bromine atom, or iodine atom + R1 represents a hydrocarbon group having 1 to 20 carbon atoms 1m
It is a number from 0 to 4. ) in the presence of a hydrocarbon solvent (hereinafter referred to as "component A"), and [B] 2 R2nAtx4-n (wherein X2 is the above) Represents the same atom as X1, R2 represents an alkyl group having 1 to 12 carbon atoms, or (d represents a phenyl group,
n is a number greater than 1 and less than 6. ) (hereinafter referred to as "component B") at a temperature of 125°C or higher, 2
This is a method for polymerizing ethylene, which is characterized by polymerizing under a pressure of 'ooK7/- or more.

According to the present invention, the following excellent effects are achieved.

(1) Since both component [A] and component [B] are liquid, they can be easily supplied to a single polymerization reactor.

(2) Component [A] and component [B') can be quantitatively supplied to the polymerization reactor.

(3) It is easy to control the supply amounts of component [A] and component [B] in response to pressure fluctuations in the polymerization reactor.

(4) Since component [A] and component [B] are well dispersed in the polymerization reactor, a polymer of uniform quality can be obtained.

(5) Significantly higher yields of polymer are obtained per catalyst used.

In the present invention, component [A] is prepared under an inert gas atmosphere such as nitrogen or argon.

The magnesium naphthenate used in the present invention is.

For example, it can be prepared by a reaction known per se as described below.

(1) Reaction between dialkylmagnesium and naphthenic acid.

(2) Reaction between metallic magnesium and naphthenic acid.

(3) Reaction between Macui sium oxide and naphthenic acid.

Specific examples of titanium compounds include titanium tetrachloride, titanium tetrabromide, metquin technotrichloride, ethoxytitanium trichloride, butoxytitanium trichloride, octoxytitanium trichloride,
Dodecacoxychikune Ylichloride, fenoquine titanium trichloride, benfuki/titanium trichloride, ethoxychikune tribromide, ethoxytitanium tribromide, Shedkin titanium dichloride, cyphytoxychikune dichloride, dihexoxytitanium chloride, triethoxy Titanium chloride, trypoxytitanium chloride, trihexoxytitanium chloride, trioctoxytitanium chloride.

Tetoshimethquin titanium, tetraethquin titanium.

Examples include tetrabutoxytitanium and tetraoctoxytitanium. The usage notification for titanium compounds is o,oos to 1 mole, especially 0.
The amount is preferably 01 to 0.5 mol.

Specific examples of hydrocarbon solvents include pentane, hexane,
Examples include aliphatic hydrocarbons such as heptane, monoalicyclic hydrocarbons such as cyclopenkune and cyclohexane, and aromatic hydrocarbons such as benzene, toluene, and xylene.

The amount of hydrocarbon solvent used is usually 1 to 100 t per mole of naphthenate.

There is no particular restriction on the method of bringing Naphthenoic acid sium and the titanium compound into contact in the presence of a hydrocarbon solvent9, and for example, the following methods can be employed.

(1) A method of adding a titanium compound to a hydrocarbon solvent solution of magnesium naphthenate.

(2) A method of adding the above solution to a titanium compound.

(3) A method of adding a hydrocarbon solvent solution of a titanium compound to the above solution.

(4) A method of adding a solution of magnesium naphthenate to a solution of a titanium compound.

The contact temperature is usually 0 to 300°C, preferably 10 to 20°C.
It is 0°C. The contact time is not particularly limited and is usually 5 minutes or more.

The titanium-containing solution obtained in this way is used as is.

Alternatively, dilute with hydrocarbon solvent as needed.

Subjected to polymerization reaction.

Specific examples of the organoaluminum compound (component [B]) include diethylaluminum chloride, diptylaluminum chloride, dihexylaluminum chloride, diethylaluminium bromide, diethylaluminium iodite, diphenylaluminum chloride, and dibenzylaluminum chloride. It will be done.

The amount of organoaluminum compound used is usually 1 to 1000 moles per gram atom of titanium in the titanium-containing solution.

In the present invention, in the presence of a catalyst obtained from component [A] and component CB], ethylene or ethylene and 3-carbon
The mixture with the above α-olefin is polymerized to obtain an ethylene homopolymer or an ethylene copolymer.

Specific examples of α-olefins having 3 or more carbon atoms include hauflopyrene, butene-1,4-methylpentene-1, and octene-1.

Polymerization pressure is 200 Kg/- or more, preferably 500 Kg/- or more
~3000 is 9/-. Polymerization temperature is 125℃ or higher,
Preferably it is 150-3'50°C. The average residence time of the monomer within the polymerization system is 2 to 600 seconds.

Preferably it is 10 to 150 seconds.

As the polymerization apparatus it is possible to use a tube reactor or a seed reactor.

The molecular weight of the polyethylene produced can be easily controlled by adding a molecular weight regulator 3, such as hydrogen, to the monopolymerization system.

Next, examples will be shown. In the examples, "1 polymerization activity" means the yield of polyethylene (Kg) per titanium 17 in the component CAI used, and "M" means the AS
Melt index of polyethylene measured at 190° C. under a load of 2.1 bKy according to TM D 12'3B.

Example 1 (1) Preparation of titanium-containing solution (component [A]) Commercially available naphthenic acid was vacuum distilled at 2 mm Hf.
The fraction at ℃ was collected. Purified naphthenic acid thus obtained5. In addition to V-Ryu n-Heflin 8L.

To this solution, 2 t of n-heflin solution containing 2.5 mol of di-n-hexylmagui sium was gradually added at 0°C. Thereafter, the temperature of the solution was raised to 90° C. and stirred at the same temperature for 1 hour to obtain a pale yellow transparent solution.

After cooling this solution to room temperature, 5 mol of tetra-n-butquine titanium Q and O were added under stirring to obtain a reddish-orange homogeneous solution. Add this solution to Shellzuru 71 (manufactured by Shell Chemical)! It was diluted with i5.7t to obtain component [A].

(2) Into the reaction tube of Polymerization Summary 400771, add 60% ethylene by weight,
Monomer consisting of butene-140 weight and hydrogen of 0.2 volume per monomer are continuously supplied, and 200
Ethylene and butene-1 were copolymerized under pressure of oKg/ca.

Scherzl 71 solution of diethylaluminum chloride as the above component [A] and component [B] (concentration: 45
0 mmol/A), 4 t/hour and 3.0 mmol/A), respectively. "l
It was continuously fed at a rate of 1/hr from an injection point provided at the inlet of one reaction tube. The temperature inside the reaction tube is 145℃ at the inlet.
The maximum temperature was maintained at 250°C. The flow rate of the monomer in the reaction tube was 10 m/sec. The above continuous operation was performed for an order of magnitude of b hours.

M, 1.5.11jI/1o min, density 0.921 f
An ethylene/butene-1 copolymer with a polymerization activity of 540 was obtained.

Examples 2 and 3 Ta. The results are shown in Table 1.

Examples 4 and 5 Example 1 was repeated, except that instead of tetra-n-butoxytitanium, 0.35 mol of the titanium compound listed in Table 2 was used. The results are shown in Table 2.

Claims (1)

[Claims] Ethylene or a mixture of ethylene and an α-olefin having 6 or more carbon atoms. [A] Magnesium naphthenate. Formula X'rnT1(OR1)4-m (in the formula, +
is a number from O to 4. ) in the presence of a hydrocarbon solvent, and a titanium-containing solution obtained by contacting a titanium compound represented by R2
represents an alkyl group having 1 to 12 carbon atoms or a phenyl group, and is a number less than 3, which is greater than nba1. ) in the presence of a catalyst obtained from an organoaluminum compound represented by
0 (a method for polymerizing ethylene characterized by polymerizing under pressure of +Kg/crA or more.