CN1032342A - The transition metal catalyst component that contains magnesium alkoxy alkoxides - Google Patents

Abstract

Preparation of transition metals by reaction of magnesium alkoxides with titanium tetrachloride Component Ziegler-Natta catalysts. The transition metal component and An aluminum compound is reacted to prepare a catalyst for olefin polymerization.

Description

The invention is an improved magnesium carrier anion coordination catalyst for olefin polymerization.

Many anionic coordination catalyst systems are based on the use of titanium-based catalysts on magnesium chloride supports.

A typical catalyst system using magnesium chloride is disclosed in British Patent 2,111,066 (licensed to Mitsui Petrochemical Industries Ltd.).

Certain prior art patents teach Ziegler-Natta type catalysts supported on magnesium compounds, but do not use magnesium chloride directly in the catalyst preparation. Specifically, U.S. Patent 3,644,318 describes a mixed catalyst component which is the reaction product of a magnesium alkoxide and a tetravalent titanium halide compound.

Other prior art patents employing alkoxides as magnesium sources to form olefin polymerization catalysts are: U.S. Patents 4,144,390; 4,277,372; 4,460,701; 4,485,186; , No. 497,905, and U.S. Patent No. 31,099 of new edition.

Co-pending application 06/861,392 (filed September 5, 1986) finds that highly organic solvent soluble magnesium alkoxides can be prepared if magnesium is reacted with an alkyl alcohol. The obtained alkoxymagnesium alkoxide derivatives are easily soluble in organic solvents such as hexane, heptane, toluene, xylene and the like.

The prior art has not recognized the advantages of magnesium alkoxyalkoxides which are highly soluble in organic solvents. Furthermore, the prior art generally uses halogenating agents rather than transition metal halides, which are usually part of the polymerization catalyst.

This necessitates the development of a new anion-coordination catalyst system with a new source of Mg as a support for Ti-based catalysts.

The present invention is an anion coordination catalyst component, which is formed by the reaction of alkoxy magnesium alkoxide and titanium tetrachloride. Furthermore, the present invention is an anionic coordination catalyst suitable for olefin polymerization by making (i) a reaction product of a magnesium alkoxide alkoxide compound and titanium tetrachloride and (ii) an organoaluminum compound prepared by compounding.

Ziegler-Natta type anion coordination catalysts are usually prepared by combining a transition metal component with an aluminum co-catalyst. Ideally, the titanium catalyst component is first formed and then combined with the aluminum cocatalyst just before use. The present invention combines titanium tetrahalide with magnesium alkoxide alkoxide to form a first transition metal catalyst component in the absence of an aluminum cocatalyst or additional halogenating agent dopant.

The catalyst system of the present invention is a titanium-containing catalyst component using a magnesium-containing carrier. The magnesium support is formed by reacting a magnesium alkoxide with titanium tetrachloride.

Magnesium alkoxylate catalyst components suitable for use in the process and the formation of the catalysts of this invention are described in co-pending patent application filed 9/5/86. Suitable magnesium alkoxylates can be represented by the formula:

In the formula, n and m are the same or different positive integers from 1 to 12; Z is (R ₁ O)- or (R ₁ )-, and R ₁ and R ₂ are the same or different from 1 to 20 carbon atoms the hydrocarbon group. For a preferred magnesium alcohol, _R1 and _R2 are alkyl groups containing 1 to 12 carbon atoms, and the integers n and m are each less than or equal to 4.

Typical magnesium alkoxylates are as follows:

Magnesium bis(2-methoxyethanol)

Magnesium bis(2-ethoxyethanol)

Magnesium bis(2-butoxyethanol)

Magnesium bis(3-methoxypropanol)

Magnesium bis(3-ethoxypropanol)

Magnesium bis(3-propoxypropanol)

Magnesium bis(3-propoxypropanol)

Magnesium bis(3-methoxypropanol)

The alkoxy magnesium alkoxide used in the preparation of the catalyst of the present invention is prepared by direct reaction of metal magnesium and one or more alkoxy alcohols to prepare G? Miscellaneous extravagance recovery  granules 绲饣蚵ran  about uranium Qiu Jia Wei Na  evil from Α M 檠  Jia Wei tomb ㄌ 卣 nightmarish Amaranthus yi mo Xie  芗 dysentery protection  诒 mu ㄒ草见装团ㄔ? 0 ℃), in toluene or 2-methoxyethanol or 2-butoxybutanol, the solubility is at least 15% by weight.

The transition metal polymerization catalyst component is formed by reacting (i) magnesium alkoxide alkoxide with (ii) titanium tetrachloride. The molar ratio of magnesium alkoxide alkoxide (i) to titanium halide (ii) is from 1:5 to 1:1000, preferably from 1:10 to 1:300. Generally, the magnesium and titanium reactants are combined above room temperature, typically about 40°C to about 150°C. Response time is not critical, but usually takes several hours. The product of the titanium catalyst component in the first step is black powder in appearance and typically contains 0.5 to 10% titanium.

The titanium catalyst product of the first step may be under inert conditions before it is combined with the cocatalyst components.

Suitable aluminum cocatalysts are selected from aluminum alkyls, aluminum halides and/or organic halides of aluminum. The aluminum component can be represented by the following formula:

In the formula, R is an organic group, X is a halogen selected from chlorine, bromine or iodine, and n is zero or an integer of 1 to 2. The molar ratio of titanium tetrahalide to aluminum component in the combined catalyst system is from about 1:5 to about 1:500. The transition metal catalyst component and the aluminum cocatalyst are combined by simple mixing, although grinding together may be done if desired.

A wide variety of catalyst additives are available, including activators and electron donors, which can be used in combination with the main magnesium alkoxide, titanium tetrachloride, and aluminum catalyst components.

Preferably, the aluminum cocatalyst component is added to the titanium component just before polymerization with the catalyst.

Catalytic promoters, such as electron donors, are useful to increase the efficiency of the catalysts of the invention. Typical electron donors are selected from monocarboxylates, fatty carboxylic acids, carboxylic anhydrides, ketones, fatty ethers, and organosilicon compounds. Illustrative electron donating agents are phthalic anhydride, diisobutyl phthalate, phenyltriethoxysilane and diphenyldimethoxysilane. Specifically, aromatic polycarboxylic acid esters such as: monoethyl phthalate, dimethyl phthalate, methyl ethyl phthalate, isobutyl phthalate, phthalic acid Diethyl ester, ethyl isobutyl phthalate, di-n-propyl phthalate, di-isobutyl phthalate, di-n-heptyl phthalate, di-2-phthalate Ethylhexyl phthalate, Di-n-octyl phthalate, Di-neopentyl phthalate, Didecyl phthalate, Benzyl butyl phthalate, Diphenyl phthalate, Naphthalene di- Diethyl carboxylate and dibutyl naphthalate can be used as additives.

The polymerization of olefins is accomplished by bringing the olefins and the polymerization catalyst of the present invention into contact with each other in a liquid reaction medium. The liquid reaction medium is typically selected from liquid propylene, heptane, hexane, benzene, toluene or mixtures thereof. Polymerization conditions are generally not critical. The polymerization reaction is carried out in the liquid phase (solution or suspension), and the reaction temperature is from about 0°C to the boiling point of the liquid phase. Generally, a temperature in the range of 15°C to 150°C is suitable. The pressure can be below, at or above atmospheric pressure. Alternatively, hydrogen can be used at moderate pressure to control the molecular weight of the reaction product.

The catalysts of the present invention can be used in the polymerization of ethylene, alpha-olefins or mixtures thereof. The polymerization of propylene particularly requires the use of the catalyst of the present invention.

The practice of the present invention is illustrated by the following examples, but is not limited to the following examples.

Example

Part A - Preparation of bis(2-butoxyethoxy)magnesium (DBEM)

125 ml of 2-butoxyethanol and 250 g of heptane were charged to the flask and brought to reflux. Magnesium metal (12.9 g) was added to the flask in small portions to control the vigorous evolution of hydrogen gas. After all the magnesium metal had been added, the mixture was refluxed for one hour. The colorless mixture was filtered to remove a small amount of black precipitate to obtain 313 g of magnesium alkoxide solution.

Part B - Preparation of Catalyst

29.4 grams of Part A solution was used, containing a total of 10.3 grams of DBEM. 35 ml of decane and 2.1 g of phthalic anhydride were added to the DBEM solution. The resulting solution was added dropwise to 200 ml of titanium tetrachloride kept at -20°C. The dropwise addition was carried out for 45 minutes, after which the reaction mixture was heated to 110°C over 3 hours. Upon heating to 110°C, 2.9 g of diisobutyl phthalate were added. The mixture was kept at 110°C and stirred at 350 rpm for 2.5 hours. The mixture was filtered at 110°C to obtain a solid powder.

The solid thus formed was mixed with 275 ml of titanium tetrachloride and heated at 110°C for 2 hours. Then, 200 ml of toluene were added, and the mixture was heated at 110°C for 40 minutes. The mixture was filtered at 110°C, and the resulting solid was washed three times with hexane and dried in vacuo. 6.2 g of black powder containing 6.55% titanium were obtained.

Part C - Polymerization of Propylene

The catalyst prepared in part B was tested in the propylene polymerization test. 150 milligrams of catalyst, 10 millimoles of triethylaluminum, and 0.5 millimoles of diphenyldimethoxysilane were added to a 4.5-liter autoclave previously filled with 2 liters of hexane. Hydrogen was introduced at a pressure of 2 psig (13790 Pa), the reactor was pressurized to 100 psig (689,500 Pa) with propylene and the temperature was maintained at 70°C while stirring at 400 rpm. After 2 hours, the contents were removed. 1360 g polyethylene/g catalyst were obtained. The identity index of the polymer was 94.8%.

Claims (3)

1. A method for producing a transition metal polymerization catalyst component, comprising (i) a magnesium alkoxide alkoxide soluble in an organic solvent, represented by the following formula: In the formula, n and m are the same or different positive integers from 1 to 12, Z is (R ₁ O)-a(R ₁ )-, and R ₁ and R ₂ are carbon atoms containing 1 to 20 carbon atoms, The same or different hydrocarbon groups; react with (ii) titanium tetrachloride, wherein the molar ratio of (i) to (ii) is 1:5 to 1:1000. 2. The method according to claim 1, wherein _R1 and _R2 are an alkyl group of 1 to 12 carbon atoms, and n and m are each a number less than or equal to 4. 3. A process according to claim 1, wherein the magnesium alkoxylate is selected from the group consisting of: Magnesium bis(2-methoxyethanol) Magnesium bis(2-ethoxyethanol) Magnesium bis(2-butoxyethanol) Magnesium bis(3-methoxypropanol) Magnesium bis(3-ethoxypropanol) Magnesium bis(3-propoxypropanol) Magnesium bis(3-methoxybutanol)