JPS59210907A - Production of ethylene polymer - Google Patents

Abstract

PURPOSE:To produce a high-quality polymer at a high production rate, by (co)polymerizing ethylene at a high temperature and a high pressure in the presence of a catalyst obtained by combining a reaction product between a trialkylaluminum compound and water with a titanium-containing catalyst component. CONSTITUTION:A trialkylaluminum compound (e.g., trimethylaluminum) is reacted with water to produce a reaction product of formula I or II (wherein n>=1). A polymer is obtained by (co)polymerizing ethylene at a pressure >=200kg/ cm<2> and a temperature >=130 deg.C in the presence of a catalyst obtained by combining the above reaction product with a solid catalyst component obtained by reacting a trivalent or tetravalent titanium compound (e.g., titanium tetrachloride) with a magnesium dichloride or a magnesium alcoholate or a solid catalyst component obtained by further treating the above solid catalyst component with an organoaluminum compound.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention utilizes a novel highly active Ziegler-type catalyst to achieve pressures of at least 200 ki7107 and
This invention relates to a method for homopolymerizing and copolymerizing ethylene at a temperature of 30°C.

There are two methods for industrially producing ethylene polymers: The $1 method uses a catalyst that can generate free radicals and polymerizes ethylene at high temperature and high pressure, and is generally referred to as the "high pressure method." The second method is a method in which ethylene is polymerized under relatively low temperature and low pressure conditions using a Ziegler type catalyst, and is called the "low LE method".

Ziegler type catalysts generally fall within lVa to Vla of the periodic table.
A first method, consisting of a compound of a transition metal of a group I-Ill of the periodic table and an organic gold compound of a metal of a group I-Ill of the periodic table.
In other words, in the "high pressure method", branched polyethylene with a density of 0.935 or less is produced, and in the second method, that is, "low pressure method", a linear polyethylene with a density of 0.95 or more is produced without any branches. It is characterized by the production of polyethylene.

Incidentally, recently, in addition to the first and second methods, a third method has been proposed. This method uses an ionic polymerization catalyst such as a Ziegler type catalyst to homopolymerize or copolymerize ethylene under high temperature and pressure. The use of Ziegler type catalysts under such high temperature and pressure conditions involves many problems, as it is difficult to reliably predict the behavior of Ziegler type catalysts at high temperature and high pressures, and many proposals have been made so far. However, none of these methods are fully satisfactory in the following respects. The first point is that the catalyst activity is not high enough. If the catalyst activity is not high enough, there will be a large amount of catalyst residue in the produced polymer, and if the catalyst removal step or polymer purification step is omitted, the product will deteriorate. This may cause discoloration, deterioration, etc., and adversely affect quality.

If a catalyst removal step or a polymer purification step is required, large-scale equipment is required and the cost of producing the polymer increases significantly, so improving catalyst activity is an important factor in industrialization.

The second point is that since the polymerization is carried out at high temperatures, it is difficult to increase the molecular weight of the polymer that can be produced sufficiently.

In particular, when ethylene and α-olefin are copolymerized, it becomes more difficult to increase the molecular weight because α-olefin acts as a chain transfer agent. Therefore, due to the relationship with the 1-] standard molecular host of the produced polymer, there is an upper limit to the polymerization reaction humidity, which limits the polymer yield. Therefore, in a sufficiently high polymerization temperature range, the molecule iI
The development of catalytic yarns with good control of i is an extremely important and unresolved issue.

Based on the above, the present inventors solved these problems by 11
As a result of searching for various catalyst systems, at least 200
kg/C1? 61 at a pressure of L and at least 130°C
At 4 degrees, cA) a reaction product of l-realylaluminum and water; (B) a solid catalyst component obtained by catalytic reaction of a trivalent or tetravalent titanium compound and a magnesium dihalide or a magnesium alcoholade; or , by homopolymerizing ethylene or copolymerizing ethylene with at least 14 Ij of α-olefin using a catalyst system consisting of a solid catalyst component obtained by further treating the solid catalyst component with an organoaluminum compound. The inventors have discovered that this problem can be solved and have arrived at the present invention.

Among the effects brought about by the present invention, the most distinctive effects are:
a pressure of at least 2ookg/d and a pressure of at least 13
Since the catalyst activity is high at a temperature of 0'C, there is little catalyst residue in the produced polymer, which does not adversely affect the quality of the obtained product.

Furthermore, since the present catalyst system has extremely high initial polymerization activity, it also has the characteristic that sufficient productivity can be obtained with a very short residence time. Another effect is that the present catalyst system allows good control of the molecular weight of the obtained polymer, so that the molecular weight of the polymer can be made sufficiently high even in a sufficiently high polymerization temperature range.

In the present invention, a reaction product of trialkylaluminum and water is used as one of the catalyst components, and specific examples of trialkylaluminum include: Examples include n-butylaluminum, triisobutylaluminum, trihexylaluminum, trioctylaluminum, or mixtures thereof.

The reaction of the above trialkylaluminium and water is a condensation reaction, and the resulting product varies depending on the molar ratio of both reaction components and reaction conditions, but the product has the general formula (where n is 1 or more).
It is a mixture of condensates represented by (an integer of ). The above reaction can be easily carried out by gradually adding a predetermined amount of water to trialkylaluminum dissolved in an inert solvent such as hexane, and if necessary heating it slightly. The amount of water used is usually a trialkylaluminum or 0.4 to 12 molar ratio. Outside this range, the catalytic activity decreases rapidly.

A specific example of the trivalent titanium compound used in the production of the solid catalyst component (I) of the present invention is titanium trichloride,
Those made by the hydrogen reduction method, or solid solutions or compositions with various metals containing titanium dichloride as the main component, especially those made by the aluminum reduction method T ] C l! 3・-
5AIC (13) is preferably used.

Furthermore, a product obtained by treating titanium trichloride with an alcohol or other electron-donating compound can also be used.

Examples of the tetravalent titanium compound include the following compounds.

K # ← F in column 1 (a) General formula T i (OF2) lX', i (where R' is an aliphatic alicyclic or aromatic hydrocarbon group having at most 8 carbon atoms; , X' represent ).rogen atoms, and l is a number satisfying O≦l≦4. ), and preferred representative examples thereof include titanium tetrachloride, titanium tetrachloride, mer-A=sititanium trichloride,
Ethoxytitanium trichloride, propoxytitanium trichloride, butoxytitanium trichloride, dibutoxytitanium dichloride, dibutoxytitanium dichloride, tributoxytitanium chloride, tetrabutoquine titanium, tetrapropoquine titanium, tetrabutoquine titanium (here R1 The polytitanate is an aliphatic alicyclic or aromatic hydrocarbon group having at most 8 carbon atoms, and m is an integer from 2 to 10. This polytitanate is obtained by partially hydrolyzing titanium alkoxy compounds, and representative examples include jetoxytitanium dimer, jetoxytitanium trimer, dipropoxytitanium dimer, dipropoxytitanium tetramer, and jetoxytitanium dimer. Examples include toxytitanium dimer and jetoxytitanium dimer.

(c) The titanium compounds shown in (a) and (g) above are used in electronic devices. Electron-type compounds are those that have at least one polar group, and representative examples of preferable examples include ether compounds, carboxylic acid compounds, alcohol compounds, and ester compounds. be.

Examples of the magnesium dihalide include magnesium chloride, magnesium bromide, and magnesium fluoride, but magnesium chloride is particularly preferred. Furthermore, dihalogenated magnesium which has been contacted with an electron-donating compound can also be used.

Examples of the magnesium alcoholade include magnesium methylate, magnesium ethylate, magnesium alcoholade, and magnesium butylade, with magnesium ethylate being particularly preferred.

The catalytic reaction between a trivalent and/or tetravalent titanium compound and a magnesium dihalide or a magnesium alcoholade is
FL can be carried out by any generally known method, but preferred methods include mechanically pulverizing these compounds (hereinafter referred to as "co-pulverizing method") and pulverizing them in an inert solvent or in an inert solvent. There is a method of contacting in the absence of an active solvent. The co-pulverization method is usually carried out by co-pulverizing a sium thread compound and a transition metal compound, or these compounds and an electron-donating compound and/or an alkyl metal compound in order to produce a solid catalyst component for olefin polymerization. Just apply the method provided.

Generally, this co-pulverization is carried out at around room temperature under an inert gas atmosphere. Although the time required for co-pulverization cannot be absolutely specified depending on the performance of the crusher, it is preferable that the material to be crushed be in a uniform state, and is generally 5 minutes to 24 hours. Further, among the contact methods, methods other than the co-pulverization method are methods of processing in the presence or absence of an inert solvent. The inert solvent used in this process is dry, typically with a boiling point of
Examples include aliphatic hydrocarbons, alicyclic hydrocarbons, and aromatic hydrocarbons having a molecular weight of 0 to 300'G, as well as halogen compounds thereof. Contact 1 & li: The degree varies depending on the contact force "J" and the percentage contact time, usually between 20°C and 25°C.
It is 0°C. The duration of contact 11 is generally 5 minutes to 21 hours. In any of the above co-pulverization methods and contact methods, the ratio of trivalent and/or tetravalent titanium compound to 1 mol of magnesium compound is generally 001 to 0.
The amount is preferably 20 moles, and preferably 0.02 to 10 moles. The solid catalyst component thus obtained may be washed with an inert hydrocarbon solvent, if necessary.

The solid catalyst component (III) of the present invention can be obtained by further treating the solid catalyst component (I) obtained as described above with an organoaluminum compound. If machine aluminum compound has the general formula flJX", -n (where R3 is an alkyl group having at most 8 carbon atoms,
, X2 represents a hydrogen atom or a halogen atom, and n is 1 to
The number is 3. ) Preferred representative examples thereof include: ) - ethylaluminum triisobutylaluminum; - lihequinaluminum, trioctylaluminum, diethylaluminium chloride, cyphthylaluminum chloride, ethylaluminum Examples include skichloride, ethylaluminum dichlorite, diethylaluminum uno\hydride, and sifthylaluminium hydride. The processing method is carried out in the presence or absence of an inert solvent.

Processing heat treatment is used by the God of aluminum compound 'L'
gf and; to 0°C~
200℃ is preferable. The period between treatments +1' and 7 is generally 5 minutes to 0 hours. The reaction ratio between the solid catalyst component (I) and the organoaluminum compound is 0.1 to 50 moles, particularly 0.5 to 30 moles, per 1,000 moles of Ti material contained in the solid catalyst component (I). preferable. Solid catalyst component (II) thus obtained
was washed several times with an inert hydrocarbon solvent and
Used in R combination.

The polymerization method of the present invention can be carried out either batchwise or continuously. As the polymerization apparatus, an apparatus generally used for high-pressure radical polymerization of ethylene can be used, and specifically, a stirred acid tank type reactor or a back type reactor is used. (The R combination is also carried out in the single reaction 'MV range, but 1
The reaction can be carried out by dividing the interior of one reactor into several zones, or by connecting a plurality of reactors. When multiple reaction zones or multiple reaction systems are used, polymers of various qualities can be produced by varying the temperature, pressure, unit composition, etc. for each reaction zone.

The catalyst is deposited as a fine dispersion in a suitable inert solvent directly into the reactor by high-pressure pumps, resulting in small particle sizes.
It must have good dispersibility in solvents. A generally known method for making catalyst particles finer is to prepolymerize with an α-olefin having 6 or more carbon atoms. Suitable inert solvents include hydrocarbons such as hexane, heptane, decane, toluene, isoparaffins, and cyclohexane. The catalyst may be injected into the reactor by premixing component A and component B, or alternatively, component A and component B may be separately injected into the reactor under pressure.

Further, when performing the reaction in multiple reaction zones, the injection may be carried out all at once in the first reaction zone, or may be divided and injected into other reaction zones.

A/! of component A and component B during polymerization! '/Ti atomic ratio is 1~
]000, preferably 200.

The polymerization carried out using the catalyst threads of the invention is a 11i homopolymerization of ethylene or a copolymerization of ethylene with at least one α-olefin. Specific examples of α-olefins include propylene, butene-1, hexene-1, ]ocden-1decene-1, 4-methyl-pentene-1, and the like. Copolymerization of these α-olefins 112j
generally at most 30 mol%, and 20 mol%
It is preferred.

The polymerization pressure employed in the present invention is 200 kg/
The pressure is over 67, preferably 300-4000
kg/ffl, more preferably 500 to 3000 kg
/i. The polymerization temperature is at least] 30°C, preferably in the range 150-350°C. The average residence time in the reactor is related to the duration of activity of the catalyst under the polymerization conditions employed, but is generally between 5 and 6.
00 seconds, preferably 10 seconds to 200 seconds. Further, in the present invention, hydrogen can be used as a molecular weight regulator of the polymer within a range of 0 to 20 mol%.

In the following, the present invention will be explained in more detail with reference to Examples.

In addition, in the Examples and Comparative Examples, Melt Intex (hereinafter referred to as -M, ■) is JISK-676
Measurements were made under the conditions of 190° C. and a load of 2.1.6 kg. The smooth density is JIS K-6760
Measured according to

Example 1 Reaction of trialkylaluminum compound and water 60 ml of hebutane and 60 mmol of triethyl aluminum were added to a 300 ml three-day flask purged with nitrogen, and -3
Add 30 vunol of water dropwise at 0°C.

After the addition, the temperature was gradually raised to 2' and stirring was continued at +o'c for 10 hours to complete the reaction and obtain a reaction product (A-1).

Preparation of solid catalyst component Anhydrous magnesium chloride (by heating and drying commercially available anhydrous red sea bream chloride in a stream of dry nitrogen at about 500'C for 15 hours)20.
4 g of 9AA type titanium trichloride was placed in a container for a vibrating mill (stainless steel, cylindrical, internal volume 1 g, diameter: J, Omm).
A porcelain ball (50% vertical filling) was placed in the container. This was placed in a vibrating ball mill with an amplitude of 6 mm and a frequency of 301 mm, and a homogeneous co-milled product (B-1) was obtained by co-milling for 8 hours.

High-pressure polymerization of ethylene 500 ml of thoroughly dehydrated heptane was placed in a flask with a stirrer (No. 1, 51) purged with nitrogen, and 40 mmol of the reaction product of 2.5 g of the solid catalyst synthesized above, toluethylaluminum, and water (Al atoms ) was added and preactivated. Next, fully dehydrated and purified hexene-1
was added so that the hexene/Ti molar ratio was 20, and the mixture was stirred for 2 hours to obtain a fine catalyst suspension. This catalyst suspension was pumped into a stirring autoclave type reactor having an internal volume of 21 cm, and ethylene homopolymerization was carried out under the conditions shown in Table 1.

Molecule f of the polymer produced, flI? 1. ', hydrogen was used for section 1. As a result of heavy testing, 43.8 kg of polymer was obtained per 19 solid catalyst components.

Examples 2 to 5 By changing the polymerization conditions as shown in Table 1, homopolymerization of ethylene was carried out to 1 J using the catalyst yarn used in Examples. The results are shown in Table 1.

Table 1 Examples 6-10. Comparative Examples 1, 2 1. In the reaction between realgyl aluminum and water,
A reaction product of trialkylaluminum and water was synthesized in the same manner as in Example 1, except that the kIr+ J3'+ of l-realkylaluminum and the reaction ratio were as shown in Table 2, and the reaction product was synthesized in the same manner as in Example 1. A catalyst suspension was prepared by the method.

Using this catalyst suspension, ethylene and butene-1 were copolymerized under the conditions shown in Table 2. The results are shown in Table 2.

Example 11 ~] 11 20 & of anhydrous magnesium chloride used in the production of the solid catalyst component (B-1) and 4 g of dibutoxytitanium dichloride were co-pulverized under the same conditions as in the production of the solid catalyst component (B-1,). A homogeneous co-ground product was obtained. Of the co-ground material, 15g was added to 1.00 m of n-hexane.
1 of diethylaluminum chloride was further added, and the mixture was treated at 40°C for 2 hours. By thoroughly washing the obtained solid component with n-hexane,
A solid catalyst component (B-2) was obtained. The solid catalyst component (B-2) thus obtained and the reaction product (A) of triethylaluminum and water synthesized in Example 1
A catalyst suspension was prepared in the same manner as in Example 1 using -1,). Using this catalyst suspension, copolymerization of ethylene and α-olefin was carried out under the conditions shown in Table 3.

The results are shown in Table 3.

Example 15 60 ml of n-hebutane, 20 ml of % magnesium ethylate, and 40 mmol of titanium tetrachloride were added to a 300 m, 1 three-bottle flask that was sufficiently purged with nitrogen.
A solid reaction product was obtained by stirring at 0'C for 3 hours. After thoroughly washing this with n-hexane, 20 ml of ethylaluminum sesquichloride was added, and 4
A brown solid component was obtained by treatment at 0° C. for 2 hours. A solid catalyst component (B-3) was obtained by thoroughly washing this solid component with n-hexane. Example 11 Using the thus obtained solid catalyst component (B-3)
A catalyst suspension was prepared in the same manner as in Example 2, and copolymerization of ethylene and butene-1 was carried out under the same conditions as in Example 2.

As a result, 0.5 kg of polymer was obtained per 1 g of the solid catalyst component. The Ml of the polymer is 0.40. Density is 0
925: Ude was.

Patent applicant: Shof1J Electric Works Co., Ltd.

Claims (1)

Claims: Fit of ethylene and at least one α- A method for producing an ethylene polymer characterized by copolymerizing an ethylene polymer with an olefin. Component A, a reaction product of a l-realkylaluminum compound and water, Component B, a trivalent or tetravalent titanium compound, and a dino-logenated Magi compound.・Solid catalyst component (], ) obtained by catalytic reaction with sium or magnesium alcoholade, or solid catalyst component (II) obtained by further treating the solid catalyst component with an organoaluminum compound