KR101123154B1 - Deactivating agent of transition metal catalyst and method for deactivation of catalyst therewith - Google Patents

Abstract

The present invention relates to a deactivator composition for effectively deactivating a transition metal catalyst used in a polyolefin polymerization and a deactivation method of a transition metal catalyst using the deactivator composition. The discoloration and decomposition of the prepared olefin copolymer is minimized, and the adverse reaction of the unreacted monomer is effectively suppressed, thereby improving the uniformity and safety of mechanical properties.

Polyolefin, transition metal catalyst, inert

Description

Deactivator of transition metal catalyst and method for deactivating the catalyst using the same {DEACTIVATING AGENT OF TRANSITION METAL CATALYST AND METHOD FOR DEACTIVATION OF CATALYST THEREWITH}

The present invention relates to a deactivator for effectively deactivating a transition metal catalyst used in a polyolefin polymerization and a method of deactivating a transition metal catalyst using the deactivator.

Olefin polymers, in particular ethylene or propylene homopolymers and copolymers of ethylene or propylene with higher alpha-olefins are used in a variety of articles, such as films, fibers, molded or thermoformed articles, pipes, coatings and the like.

Processes for the preparation of olefin polymers, such as the preparation of ethylene or propylene homopolymers or copolymers of ethylene or propylene with higher alpha-olefins, are already known. Particularly preferred polymerization reactions are high temperature or solution polymerization processes, examples of which are described in CA 660896.

DE 4338414 C1 also describes a method using an empty tubular reactor, by introducing ethylene to the bottom of the reactor and releasing the product of oligomerization from the bottom portion of the reactor along with solvent, dissolved ethylene and catalyst.

In the solution process, precise control of the degree of polymerization and the molecular weight of the obtained polymer is achieved by controlling various conditions such as reaction temperature. And the termination of the polymerization is usually terminated by the addition of what is called "inactivator".

Catalysts that can often be used for oligomerization of ethylene are, for example, two-components comprising zirconium compounds such as zirconium tetraisobutyrate as described in DE 4338416 C1 and DE 19812066 A1 and aluminum compounds which are active agents such as ethyl aluminum sesquichloride. It is a catalyst.

As already described in the prior art, rapid deactivation of the catalyst leaving the oligomerization reactor and removal of the catalyst from the desired product stream of linear alpha-olefins is a major problem in the oligomerization process. DE 4338414 C1 describes the deactivation of the catalyst by the addition of water, alcohols or fatty acids. However, separating the deactivated catalyst components from the organic phase comprising linear alpha-olefins is still complicated and expensive.

DE 19807226 A1 describes a process for deactivating a complex metal organic catalyst in a homogeneous process such as oligomerization of ethylene, which mixes the resulting product solution with a metal hydroxide in a protic solvent to deactivate and separate the catalyst from the organic phase. To do it in one step. In this process, the content of the aqueous phase is kept relatively low to a degree sufficient to deactivate the catalyst. This small amount of water phase can be dissolved or absorbed in the organic phase but is too small to form a separate phase.

In the case of the co-catalyst containing vanadium, it can be conveniently deactivated by contacting the polymerization mixture with a solution of an aliphatic monocarboxylic acid dissolved in a hydrocarbon solvent used in the polymerization process and a salt of an alkaline earth metal or zinc. This deactivation of the vanadium containing coordination catalyst improves the color of the polymer as shown in CA 1165499.

US 4,454,270 describes a process for adding an alkanol amine containing triisopropanolamine and N, N-bis (2-hydroxymethyl) soyamin to a polyolefin to deactivate the catalyst and separate the polymer from the solvent. The use of triethanolamines to improve the color of polyolefins is described in US 3,773,743. The use of diethanolamines in polyolefin compositions is also described in US 3,349,059 and US 3,389,119.

The present invention is to further improve the prior art as described above, and an object of the present invention is to provide an improved deactivator composition, which is more effective in suppressing discoloration and decomposition of a polyolefin prepared by deactivating a transition metal catalyst. .

Another object of the present invention is to provide a method for deactivating a transition metal catalyst using the deactivator.

In order to achieve the above object, one aspect of the present invention provides a deactivator composition of a transition metal catalyst comprising a metal salt of stearic acid and a surfactant.

A second aspect of the present invention for achieving the above object is to obtain a mixture comprising a solvent, a transition metal catalyst, a promoter, an olefin and a polyolefin from a polymerization reactor; Inactivating the catalyst and cocatalyst by mixing an inactivator composition comprising a metal salt of stearic acid and a surfactant to the mixture; And extracting by-products of the ligand and the organic compound of the deactivated catalyst and cocatalyst.

The olefin polymer prepared by applying the deactivator composition of the transition metal catalyst according to the present invention and the deactivation method of the transition metal catalyst for olefin polymerization using the same has an advantage of minimizing decomposition and discoloration compared to the case of using the conventional deactivator and other By suppressing abnormal reaction of unreacted monomer, mechanical properties are improved.

Hereinafter, the present invention will be described in more detail.

One aspect of the invention relates to an inactivator composition of a transition metal catalyst comprising a metal salt of stearic acid and a surfactant.

In the deactivator composition of the transition metal catalyst of the present invention, the metal salt of stearic acid is preferably selected from calcium stearate, zinc stearate, magnesium stearate, lead stearate, barium stearate or cadmium stearate, and especially calcium Stearates, zinc stearate or magnesium stearate are preferred.

In the present invention, the surfactant is a non-ionic polyoxyethylene alkyl ester (Polyoxyethylene Alkyl Ester), sorbitan fatty acid ester (Sorbitan Fatty acid ester) or polyoxyethylene alkyl amine (Polyoxyethylene Alkyl Amine) Preference is given to using a surfactant, more preferably a polyoxyethylene alkyl amine surfactant, in particular in the structure of a polyoxyethylene alkyl amine-based RN-{(C ₂ H ₂ O) x H} ₂ It is preferable to select one whose x value is 1-5. Among them, it is particularly preferable that they are alkylamine ethoxylates having 3 to 20 carbon atoms.

The transition metal catalyst in the present invention means a main catalyst containing a transition metal such as Ti, Zr, Hf, and the like, and the cocatalyst means indirectly improving the activity of the transition metal catalyst. The deactivator composition of the present invention functions to terminate the reaction by reducing the activity of the catalyst by acting on the active sites of the transition metal catalyst and the promoter, and especially when the surfactant is used to increase the rate of adsorption of the main / promoter A beneficial effect occurs in that it increases and makes the dispersion of the stearic acid metal salt uniform in the suspension of the polymer solution and the organic solvent.

A second aspect of the invention provides a method for preparing a mixture comprising a solvent, a catalyst, a promoter, an unreacted monomer and an olefin polymer from a polymerization reactor; Inactivating the catalyst and cocatalyst by mixing an inactivator composition comprising a metal salt of stearic acid and a surfactant to the mixture; And extracting by-products of ligands and organic compounds of the deactivated catalyst and cocatalyst.

In the deactivation method, the deactivator is preferably introduced into the extruder directly in the solid phase or into a vessel behind the reactor in the form of a solution suspended in an organic solvent such as hexane, for example. In addition, it is also possible to improve the dispersibility and early deactivation effect by adding a liquid deactivator to the suspension solution with the organic solvent.

The solvent for suspending the deactivator can be any kind of organic solvent such as hexane, heptane, octane and the like, and is not particularly limited.

In the present invention, the input amount of the stearic acid metal salt is preferably in the range of 100 ppm to 3000 ppm, more preferably in the range of 500 ppm to 2000 ppm, based on the total amount of the polymer produced.

In the present invention, the ratio of the amount of the stearic acid metal salt to the amount of the surfactant is preferably 1: 1 to 30: 1, and more preferably 5: 1 to 15: 1.

It is economical while sufficiently reducing the activity of the catalyst when the amount of the stearic acid metal salt and the surfactant is in the above range.

In the deactivation method of the transition metal catalyst for olefin polymerization, the step of extracting by-products such as ligands and organic compounds of the deactivated catalyst and cocatalyst may be performed using, for example, the following method. In other words, by using a vacuum pump in the extruder it is possible to remove the ligand and by-products of the catalyst and cocatalyst which may cause the odor. Nitrogen gas may be added to serve as a carrier of by-products for effective removal. In this case, the carrier may be a gas that is a gas at room temperature, such as nitrogen and carbon dioxide, and a solvent in a gaseous state in a high temperature extruder, such as water and hexane, but is not particularly limited. The metal content of the deactivated main catalyst and cocatalyst in the polymer is less than 5 ppm, so no special removal process is required.

Hereinafter, the present invention will be described in more detail with reference to specific examples. The following examples are intended to illustrate the present invention more specifically, but the scope of the present invention is not limited by the following examples.

Evaluation items in Examples and the like were measured as follows.

<Yellow Index Measurement>

Instrument: Colorimeter (HunterLab, ColorFlex)

Measuring method: Observer 2 degree was measured by C light source according to ASTM D1925.

Specimen: Pellet Form

Polymerization conditions of a polyolefin (polyethylene) in an Example etc. are as follows.

Into a 10L stainless autoclave reactor with a stirrer, continuous injection of triethylaluminum to remove polar impurities such as normal hexane, ethylene, transition metal catalyst, and water in the reactor produces 720 grams of polystyrene per hour. The reacted polyethylene polymer is fed to a twin screw extruder in a continuous amount for granulation. In this case, the twin screw extruder used has a structure in which a vacuum pump is installed to remove a solution and an unreacted substance. Extrusion granulation conditions use an extruder in which the barrel temperature is fixed at 100-240 degrees Celsius. During extrusion, the solution and unreacted material are removed to less than 5 ppm and polyethylene is pelletized by the granulator. The catalyst deactivator is made of a mixture of normal hexanes and fed into the metering pump between the rear end of the reactor and the extruder.

<Examples 1-8>

Calcium stearate, zinc stearate or magnesium stearate and surfactant CRODA Atmer 163 were dispersed in the content of the normal hexane solvent as much as the content shown in Table 1 below, and the polymer was polymerized under the reaction conditions using a metering pump. did. The effect of the catalyst deactivator was compared by measuring the yellow index of the polymerized polyethylene pellets. The measurement results of the yellow index are shown in Table 1 below.

<Comparative Examples 1-7>

Calcium stearate, zinc stearate or magnesium stearate and a surfactant, Croda (CRODA) Atmer 163 was tested in the same manner as in Example 1 except that the yellow index of the polyethylene pellets except that Was measured and the results are shown in Table 1 below.

According to the results of the above Examples and Comparative Examples, when the stearic acid metal salt and the surfactant were used simultaneously as the catalyst deactivator, the yellow index of the pellet was evaluated to be extremely low, which means that the catalyst deactivator of the present invention deactivates the catalyst as compared to the prior art. It has been shown to have a significant effect on doing so.

1 is a schematic diagram illustrating a process of extruding a polymer after adding a deactivator of a transition metal catalyst after a polymerization reaction in an polymerization process of an olefin according to the present invention.

<Explanation of symbols for the main parts of the drawings>

1: catalyst

2: promoter

3: monomer

4: reactor

5: deactivator

6: flash drum

7: twin screw extruder

8: vacuum pump

9: granulator

Claims (11)

Transitions comprising metal salts of stearic acid and nonionic surfactants of polyoxyethylene alkyl esters, sorbitan fatty acid esters, or polyoxyethylene alkyl amines Deactivator composition of a metal catalyst. The deactivator composition of claim 1, wherein the metal salt of stearic acid is calcium stearate, zinc stearate or magnesium stearate. delete The deactivator composition of claim 1, wherein the surfactant is an alkylamine ethoxylate having 3 to 20 carbon atoms. The deactivator composition of claim 1, wherein the content ratio of the stearic acid metal salt to the surfactant is 1: 1 to 30: 1. Obtaining from the polymerization reactor a mixture comprising a solvent, a catalyst, a promoter, an olefin and a polyolefin; In the mixture, non-ionic surfactants of metal salts of stearic acid and polyoxyethylene alkyl esters, sorbitan fatty acid esters, or polyoxyethylene alkyl amines are used. Inactivating the catalyst and promoter by mixing a deactivator composition comprising; Extracting the by-products of the ligand and the organic compound of the deactivated catalyst and cocatalyst, Deactivation method of the transition metal catalyst for olefin polymerization. The method according to claim 6, wherein the metal salt of stearic acid is calcium stearate, zinc stearate or magnesium stearate. delete The method for deactivating a transition metal catalyst for olefin polymerization according to claim 6, wherein the surfactant is an alkylamine ethoxylate having 3 to 20 carbon atoms. The method for deactivating a transition metal catalyst for olefin polymerization according to claim 6, wherein the input amount of the stearic acid metal salt is in the range of 100 ppm to 3000 ppm based on the total amount of the produced polymer. The method for deactivating a transition metal catalyst for olefin polymerization according to claim 6, wherein the ratio of the input amount of the stearic acid metal salt and the input amount of the surfactant is 1: 1 to 30: 1.

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