KR20240003862A - Method for preparing Ziegler-Natta catalyst for polymerization of low-density copolymer - Google Patents

Abstract

The present disclosure relates to a method for preparing a Ziegler-Natta catalyst for polymerization of low-density copolymers, and specifically, a method comprising preparing a magnesium support by reacting an alkyl aluminum compound in a branched-chain alkyl alcohol or cycloalkyl alcohol solvent. It's about. The Ziegler-Natta catalyst prepared according to the method for producing a Ziegler-Natta catalyst according to an embodiment has excellent catalytic activity, and can be used to effectively produce a low-density copolymer that can realize various physical properties and has excellent copolymerization performance.

Description

{Method for preparing Ziegler-Natta catalyst for polymerization of low-density copolymer}

The present disclosure relates to a method for producing a Ziegler-Natta catalyst for polymerizing a low-density copolymer and a method for producing a low-density copolymer using the Ziegler-Natta catalyst prepared therefrom.

Polymerization catalysts of the Ziegler-Natta (Z/N) type are catalysts for producing olefin polymers, such as ethylene copolymers. Typically, Ziegler-Natta catalysts include magnesium compounds, aluminum compounds, titanium compounds, etc. supported on a specific support.

Since the shape and size of a polymer polymerized using a Ziegler-Natta catalyst are determined by the catalyst used, it is important to manufacture a catalyst that can increase productivity and produce a uniformly distributed polymer.

Although much development work has been conducted to prepare Ziegler-Natta catalysts, some methods are not easy to manufacture catalysts in mass production, such as because the manufacturing conditions are quite sensitive or large amounts of impurities or waste are formed. U.S. Patent No. 8003741 describes a manufacturing method of dissolving a magnesium compound in alcohol and then adding a titanium compound, but it has the disadvantage that the manufacturing process is complicated and the types of materials used are many.

One embodiment is intended to provide a method for producing a Ziegler-Natta catalyst for low-density copolymer polymerization.

Another embodiment seeks to provide a Ziegler-Natta catalyst for polymerization of low-density copolymers prepared according to the production method according to the above embodiment.

Another embodiment is intended to provide a method for producing a low-density copolymer using the Ziegler-Natta catalyst for polymerizing low-density copolymers according to the above embodiment.

One embodiment includes preparing a solution containing a magnesium support by adding branched-chain alkyl alcohol or cycloalkyl alcohol to a mixture of dialkyl magnesium and a compound represented by Formula 1 below; and

A method for producing a Ziegler-Natta catalyst for polymerization of low-density copolymers is provided, which includes adding a metal compound containing titanium (Ti) to a solution containing the magnesium support.

[Formula 1]

R ¹ _x AlCl _{3 -x}

In Formula 1,

_R ¹ is each independently C _1-10 alkyl or C _3-10 cycloalkyl _; and

x is 1 to 3.

Another embodiment provides a Ziegler-Natta catalyst for low-density copolymer polymerization prepared according to the method for producing the Ziegler-Natta catalyst for low-density copolymer polymerization according to the above embodiment.

Another embodiment provides a method for producing a low-density copolymer comprising contacting an olefin monomer with a Ziegler-Natta catalyst for polymerizing a low-density copolymer according to the above embodiment.

The present disclosure relates to a method for preparing a Ziegler-Natta catalyst for polymerization of low-density copolymers, and specifically, the preparation comprising the step of reacting an alkyl aluminum compound in a branched-chain alkyl alcohol or cycloalkyl alcohol solvent to prepare a magnesium support. It's about method. The Ziegler-Natta catalyst prepared according to the method for producing a Ziegler-Natta catalyst according to an embodiment has excellent catalytic activity, and can be used to effectively produce a low-density copolymer that can realize various physical properties and has excellent copolymerization performance.

Figure 1 is a diagram showing the results of analysis of polymers prepared using the Ziegler-Natta catalyst prepared in Examples and a commercial catalyst through crystallization elution fractionation (CEF).
Figure 2 shows Examples 1-4, Example 3-4, Example 4-4, Example 5-4, Example 6-4, Comparative Example 1-4, Comparative Example 2-4, and Comparative Example 3-4. This is a diagram showing the results of observing the shape of the magnesium carrier solution prepared in through photographs.
Figure 3 is a diagram showing the results of photographic observation of the shapes of the magnesium support solution prepared in Examples 1-4 and the prepared catalyst.

The embodiments described in this specification may be modified into various other forms, and the technology according to one embodiment is not limited to the embodiments described below. Furthermore, “including” a certain element throughout the specification means that other elements may be further included rather than excluding other elements, unless specifically stated to the contrary.

Numerical ranges as used herein include lower and upper limits and all values within that range, increments logically derived from the shape and width of the range being defined, all doubly defined values, and upper and lower limits of numerical ranges defined in different forms. Includes all possible combinations of As an example, if the content of the composition is limited to 10% to 80% or 20% to 50%, the numerical range of 10% to 50% or 50% to 80% should also be interpreted as described herein. Unless otherwise specified herein, values outside the numerical range that may occur due to experimental error or rounding of values are also included in the defined numerical range.

Hereinafter, unless otherwise specified in the specification, “about” may be considered a value within 30%, 25%, 20%, 15%, 10% or 5% of the specified value.

Hereinafter, in this specification, “alkyl” is defined to mean both alkyl or cycloalkyl, and even if alkyl or cycloalkyl does not have a specific definition, it can be easily modified by a person skilled in the art who is expected to have a similar effect. It can be interpreted to include derivatives or those substituted with common substituents (e.g., halogen, etc.).

A method for producing a Ziegler-Natta catalyst according to one embodiment includes the step of reacting dialkyl magnesium and an alkyl aluminum compound in a branched-chain alkyl alcohol and/or cycloalkyl alcohol solvent, thereby producing a low-density copolymer with significantly improved catalytic activity. A method for producing a Ziegler-Natta catalyst is provided. When polymerizing a low-density copolymer using the Ziegler-Natta catalyst prepared according to the method for producing the Ziegler-Natta catalyst according to the above embodiment, the catalyst is prepared using a straight-chain alkyl alcohol such as conventional normal propyl alcohol as a solvent. The catalyst mileage can be achieved significantly higher than when using . In addition, the low-density copolymer polymerized using a Ziegler-Natta catalyst according to one embodiment has a lower ratio of high-density regions (homopolymers) and a higher ratio of low-density regions (copolymers) compared to commercial products, so it is utilized due to its high elongation. The castle is excellent. Hereinafter, a method for producing a Ziegler-Natta catalyst for polymerization of low-density copolymers according to an embodiment and polymerization of low-density copolymers using the same will be described in detail.

One embodiment includes preparing a solution containing a magnesium support (magnesium support solution) by adding branched chain alkyl alcohol and/or cycloalkyl alcohol to a mixture of dialkyl magnesium and a compound represented by the following formula (1); and

A method for producing a Ziegler-Natta catalyst for polymerization of low-density copolymers is provided, which includes adding a metal compound containing titanium (Ti) to a solution containing the magnesium support.

[Formula 1]

R ¹ _x AlCl _{3 -x}

In Formula 1,

_R ¹ is each independently C _1-10 alkyl or C _3-10 cycloalkyl _; and

x is 1 to 3.

According to the production method according to one embodiment, a Ziegler-Natta catalyst with excellent catalytic activity can be prepared by reacting dialkyl magnesium and alkyl aluminum represented by Formula 1 in a branched-chain alkyl alcohol or cycloalkyl alcohol solvent. Therefore, when polymerizing a low-density copolymer using the Ziegler-Natta catalyst prepared according to one embodiment, the low-density copolymer can be produced with significantly increased yield and/or catalyst mileage. In addition, since the catalyst has excellent comonomer reactivity, the low-density copolymer produced by the catalyst may have excellent physical properties, such as high elongation, due to a higher ratio of low-density regions compared to commercial linear low-density copolymers produced by existing technology.

The solution (or magnesium support slurry solution) containing the magnesium support prepared by the method for producing the Ziegler-Natta catalyst according to one embodiment is opaque, unlike the conventionally known magnesium support solution, that is, it is similar to the existing transparent magnesium support. It has the characteristic of lower solubility than the retardant solution. The magnesium support solution according to one embodiment can realize remarkable catalytic activity by having such solubility characteristics. Specifically, the magnesium support according to one embodiment has very stable physical properties, so it can very effectively contribute to realizing high catalytic activity. In addition, in the magnesium support of one embodiment, the transition metal is supported on the outside of the magnesium support, so the catalytic activity can be significantly increased due to the increase in the active point of the transition metal. On the other hand, in the conventional magnesium support solution (Comparative Example 1) prepared transparently, the magnesium support and the catalyst coprecipitate to form an incomplete support, and the transition metal active point is reduced due to the transition metal being supported on the inside and outside of the support. This results in a decrease in catalytic activity.

The effect realized in the above-described embodiment may be achieved by using branched-chain alkyl alcohol and/or cycloalkyl alcohol as a solvent in the manufacturing step of the magnesium carrier solution. The step of preparing a solution containing the magnesium carrier is a step of forming a complex of magnesium and alcohol. At this time, the alkyl group of the alcohol may be an important factor in the formation of the complex. In one embodiment, aluminum trialkoxide in the form of a trimer (trimolecular polymer) can be formed by using an alcohol in which branched alkyl is substituted or cyclic alkyl is substituted, resulting in magnesium -When forming an alcohol complex, the aluminum trialkoxides may clump together to form an insoluble slurry.

In one embodiment, the dialkyl magnesium may be magnesium independently substituted with linear or branched C _1-10 alkyl or C _3-10 cycloalkyl _. Or _for example, C _1-6 alkyl, C _1-5 alkyl, C _{2- 5} alkyl, -CH ₃ , -CH ₂ CH ₃ , -CH ₂ CH _{2 CH 3} , -CH ₂ CH ₂ CH ₂ CH ₃ , C _{3- 6} cycloalkyl, C _{4- 6} cycloalkyl, and C _{5- 6} cycloalkyl may be substituted with two substituents independently selected from the group. In one embodiment, the dialkyl magnesium may be Et(n-Bu)Mg (Ethyl normal butyl magnesium, BEM).

In one embodiment, the magnesium carrier may include an adduct or complex of magnesium, alcohol, and/or alkyl. For example, the magnesium carrier may be expressed as Mg(OR) ₂ ㆍa[Al _b (OR) _3b ]. At this time, a may be, for example, 0.1 to 10, 0.1 to 6, 0.5 to 6, 0.5 to 3, 0.8 to 2, 0.8 to 1.5, or 1. Additionally, b may be, for example, 0.1 to 10, 0.1 to 6, 0.1 to 5, 0.1 to 3, 0.1 to 1, or 0.2 to 0.8, or 0.5. For example, _the magnesium carrier may be Mg(OR)·[Al _0.5 ( _{OR) 1.5 ]} . In addition, R may be, for example, an alkyl group derived from alcohol, so it may be a branched alkyl group or a cycloalkyl group.

In one embodiment, the R ¹ is each independently selected from straight or branched C _1-6 alkyl, C _1-5 alkyl, C _1-3 alkyl, -CH _{3 ,} -CH ₂ CH _{3 ,} -CH ₂ CH ₂ CH ₃ , -CH ₂ CH ₂ CH ₂ CH ₃ , -CH(CH ₃ )CH ₂ CH ₃ , C _{3- 6} cycloalkyl, C _{4- 6} cycloalkyl or C _{5- 6} cycloalkyl, wherein the above R ¹ may all be the same substituent. However, this is only an example and is not necessarily limited to this.

In one embodiment, x may be, for example, 1, 3/2, 2, 5/2, or 3. Specifically, the compound represented by Formula 1 may be trialkyl aluminum (R ¹ ₃ Al) where x is 3. In one embodiment, the compound represented by Formula 1 is triethyl aluminum (C ₆ H ₁₅ Al, Triethyl aluminum) or tributyl aluminum (C ₁₂ H ₂₇ Al, Tributyl aluminum) (or Triisobutyl aluminum) ) can be.

The production method according to one embodiment may be performed under a typical organic solvent, for example, under a C _5-20 saturated hydrocarbon solvent. Specifically, pentane, hexane, heptane, octane, nonane, or decane may be used, or a mixed solvent thereof may be used.

The manufacturing method according to one embodiment may further include adding a compound represented by Formula 2 below after adding the metal compound.

[Formula 2]

R ² _y AlCl _{3 -y}

In Formula 2,

_R ² is each independently C _1-10 alkyl or C _3-10 cycloalkyl _; and

y is 1 to 2.

At this time, _the R ² is each independently linear or branched C _{1-6 alkyl} , C _1-5 alkyl, C _2-5 alkyl, -CH _{3 ,} -CH ₂ CH ₃ , -CH ₂ CH ₂ CH ₃ , -CH ₂ CH ₂ CH ₂ CH ₃ , C _{3- 6} cycloalkyl, C _{4- 6} cycloalkyl, or C _{5- 6} cycloalkyl, where R ² may all be the same substituent. However, this is only an example and is not necessarily limited to this.

In one embodiment, y may be, for example, 0, 1/2, 1, 3/2, or 2.

In one embodiment, the compound represented by Formula 2 is C ₆ H ₁₅ Al ₂ Cl ₃ (i.e., (C ₂ H ₅ ) _3/2 AlCl _3/2 )(Ethyl aluminum sesquichloride), EtAlCl ₂ (Ethyl aluminum dichloride), MeAlCl ₂ (Methyl aluminum dichloride), PrAlCl ₂ (Propyl aluminum dichloride), or BuAlCl ₂ (Butyl aluminum dichloride), and one or more types may be used simultaneously or in combination. In one embodiment, the alkyl aluminum chloride compound represented by Formula 2 may be a monomer or dimer.

In one embodiment, the molar ratio of the metal compound and the compound represented by Formula 2 is 1:0.1 to 1:15, 1:0.1 to 1:10, 1:1 to 1:10, and 1:2 to 1:10. , 1:2 to 1:8, 1:3 to 1:5, or about 1:5. However, this is only an example and is not necessarily limited to this.

In one embodiment, the molar ratio of the metal compound and the magnesium support is 1:5 to 1:30, 1:5 to 1:30, 1:10 to 1:30, 1:10 to 1:25, 1:10. to 1:20, 1:12 to 1:18, or about 1:15. However, this is only an example and is not necessarily limited to this.

In one embodiment, the metal compound may further include a transition metal, for example, a Group IV or Group V metal. Specifically, the metal compound may further include one or more metals selected from the group consisting of Zr, Hf, V, Nb, and Ta. At this time, the metal may be included in the form of chloride, alkoxy chloride, alkylate, etc., but this is only an example and is not necessarily limited thereto.

In one embodiment, the metal compound containing titanium (Ti) may include TiX ₄ or (R ³ O) _z Ti(X) _4-z . _{At this} ^time _{, _ _ _ 5} alkyl, and z is an integer from 1 to 4 (eg, 1, 2, 3, or 4). Specific examples of the metal compounds include TiCl ₄ , TiBr ₄ , TiI ₄ , Ti(OBu) ₄ , Ti(Oi-Pr) ₄ , Ti(OEt) ₄ , Ti(OEt) ₂ (Cl) ₂ , or Ti It may be (OEt)(Cl) ₃ , etc. However, this is only an example and is not necessarily limited to this.

In one embodiment, the metal compound containing titanium (Ti) may be a mixed metal compound further containing a Group V metal compound. For example, the metal compound according to one embodiment may be a mixed metal compound of a metal compound containing titanium (TiCl ₄ ) and a Group V metal compound (VOCl ₃ ) containing a Group V metal.

In one embodiment, the branched chain alkyl alcohol or cycloalkyl alcohol may be added in a mole number exceeding 1 times the mole number of the dialkyl magnesium. For example, it may be added in an amount of 1.2 times or more, 1.5 times or more, 2.0 times or more, 10 times or less, 8 times or less, 5 times or less, 4 times or less, or 3.5 times or less of the number of moles of dialkyl magnesium. or the molar ratio of the dialkyl magnesium and the branched chain alkyl alcohol or cycloalkyl alcohol is 1:1.2 to 1:10, 1:1.5 to 1:10, 1:1.5 to 1:8, 1:1.5 to 1:6, It may be 1:1.5 to 1:5, 1:2 to 1:8, 1:2 to 1:4, or 1:1.5 to 1:3.5.

In one embodiment, the branched chain alkyl alcohol or cycloalkyl alcohol may be added in a mole number exceeding twice the mole number of the compound represented by Formula 1. For example, it may be added in an amount of 2.2 times or more, 2.5 times or more, 3 times or more, 4 times or more, 10 times or less, 9 times or less, 8 times or less, or 7 times or less of the number of moles of the compound represented by Formula 1. Or the molar ratio of the compound represented by Formula 1 and the branched chain alkyl alcohol or cycloalkyl alcohol is 1:2.5 to 1:10, 1:2.5 to 1:9, 1:2.5 to 1:8, 1:2.5 to 1. :7, 1:3 to 1:10, or 1:4 to 1:10.

In one embodiment, the step of adding the branched chain alkyl alcohol or cycloalkyl alcohol is performed at a temperature of about 10°C to -50°C, 0°C to -30°C, -5°C to -25°C, -10°C to -20°C. It can be performed in In addition, after adding the branched chain alkyl alcohol or cycloalkyl alcohol, react for about 120 minutes to 300 minutes, 180 minutes to 300 minutes, 200 minutes to 300 minutes, 220 minutes to 260 minutes, or about 240 minutes. can do.

The branched-chain alkyl alcohol according to one embodiment is not particularly limited as long as it is an alcohol in which a branched alkyl group is substituted, for example, C _3-20 branched-chain alkyl alcohol, C _3-15 branched-chain alkyl alcohol. , C _3-10 branched alkyl alcohol, C _3-8 branched alkyl alcohol, C _3-6 branched alkyl alcohol, C _3-5 branched alkyl alcohol, or C _3-4 branched alkyl alcohol. It could be alcohol. Specific examples include isopropyl alcohol, isobutyl alcohol and tert-butyl alcohol, sec-butyl alcohol, 2-pentanol, 2-methyl-1-butanol, 3-methyl-1-butanol, 3-pentanol, Neopentanol, 2-methyl-2-butanol, 3-methyl-2-butanol, 2-hexanol, 3-hexanol, 2-methyl-1-pentanol, 3-methyl-1-pentanol, 4-methyl-1-pentanol, 2-methyl-2-pentanol, 3-methyl-2-pentanol, 4-petyl-2-pentanol, 2-methyl-3-pentanol, 3-methyl-3 -Pentanol, 2,2-dimethyl-1-butanol, 2,3-dimethyl-1-butanol, 3,3-dimethyl-1-butanol, 2,3-dimethyl-2-butanol It may be ethanol, 3,3-dimethyl-2-butanol, or 2-ethyl-1-butanol, or a combination of two or more of these. Additionally, since the above alcohol is only an example, there is no particular limitation as long as it is an alcohol having a branched alkyl chain.

The cycloalkyl alcohol according to one embodiment is not particularly limited as long as it is an alcohol substituted with a cyclic alkyl group, for example, C _3-20 cycloalkyl alcohol, C _3-15 cycloalkyl alcohol, C _3- It may be _{a 10} cycloalkyl alcohol, a C _3-8 cycloalkyl alcohol, a C _3-6 cycloalkyl alcohol, a C _4-6 cycloalkyl alcohol, or a C _5-6 cycloalkyl alcohol. Specific examples include cyclopropanol, cyclobutanol, cyclopentanol, cyclohexanol, cycloheptanol, cyclooctanol, cyclononanaol, cyclodecanol, bicyclo[2.1,1]hexanol, and bicyclo[2.2.1]. ]heptanol, octahydropentalenol, or octahydro-1H-indenol, or a combination of two or more of them. Alternatively, the cycloalkyl alcohol according to the above embodiment may also include an alcohol in which a cyclic alkyl group containing an unsaturated bond is substituted, and may also include a structure in which a cycloalkyl group is substituted with an arbitrary substituent, without limitation. Additionally, since the above cycloalkyl alcohol is only an example, there is no particular limitation as long as it is an alcohol having a cycloalkyl group.

Another embodiment provides a Ziegler-Natta catalyst for low-density copolymer polymerization prepared according to the method for producing a Ziegler-Natta catalyst for low-density copolymer polymerization according to an embodiment.

Another embodiment provides a method for producing a low-density copolymer using the Ziegler-Natta catalyst for polymerizing low-density copolymers according to the above embodiment. Specifically, a method for producing a low-density copolymer is provided, including the step of contacting an olefin monomer with a Ziegler-Natta catalyst for polymerizing the low-density copolymer according to an embodiment.

In one embodiment, the olefin monomer may be, for example, an olefin monomer having 2 to 20 carbon atoms, 2 to 15 carbon atoms, or 4 to 10 carbon atoms.

In one embodiment, the low-density copolymer may be, for example, a linear low-density copolymer, and as an example, may be linear low-density polyethylene.

In one embodiment, the low density copolymer has a density of 0.91 g/mL to 0.94 g/mL, 0.912 g/mL to 0.938 g/mL, 0.915 g/mL to 0.935 g/mL, or 0.915 g/mL to 0.924 g. It may be /mL, but this is only an example and is not necessarily limited to this. In one embodiment, the low-density copolymer has a melt index (MI) measured at about 190° C. according to ISO 1133:1997 or ASTM D1238:1999 of 0.1 g/10 min to 5.0 g/10 min, 0.1 g. /10 min to 4.0 g/10 min, 0.1 g/10 min to 3.0 g/10 min, 0.1 g/10 min to 2.0 g/10 min, 0.1 g/10 min to 1.0 g/10 min, 0.2 g/10 min to 1.0 g/10 min, 0.4 g/10 min to 1.0 g/10 min, or 0.5 g/10 min to 0.9 g/10 min, but this is only an example and is not intended to be limited thereto.

Hereinafter, examples and experimental examples will be described in detail below. However, the examples and experimental examples described below only illustrate some implementation aspects, and the technology described in this specification is not limited thereto.

<Example 1-1 to Example 1-4>

33 mL (30.0 mmol) of 0.9 M ethyl normal butyl magnesium (BEM, [dialkyl magnesium]) heptane solution was added to a 500 mL flask, followed by 100 mL of normal heptane. While stirring the solution, 3.50 g (15.0 mmol) of triethyl aluminum (AlEt ₃ , [aluminum compound-1]) was slowly added dropwise. Afterwards, while maintaining the reaction temperature at about 0 ℃ to -30 ℃, isopropyl alcohol (i-PrOH, [alcohol]) was slowly added dropwise in the equivalent amount as shown in Table 1 below, and the reaction was sufficiently carried out for about 4 hours to obtain a concentration of 0.2 M. A magnesium carrier slurry solution was prepared.

30 mL (6.00 mmol) of 0.2 M magnesium support slurry solution ([support]) was administered to a 100 mL flask and 3.3 mL (0.40 mmol) of 5% by weight Ti(Oi-Pr) ₄ ([metal compound]) heptane solution was added. was administered and stirred for more than 4 hours. Afterwards, 2 mL (2.00 mmol) of 1.0 M ethyl aluminum dichloride solution (C ₂ H ₅ AlCl ₂ , [aluminum compound-2]) diluted in hexane was added and stirred at room temperature for more than 6 hours to produce a red-brown catalyst (Ziegler-Natta). ) A solution was prepared.

<Example 2-1 to Example 2-4>

Carry out in the same manner as Examples 1-1 to 1-4, except that [metal compound] was changed to 3.28 mL (0.40 mmol) of 5% by weight TiCl ₄ heptane solution to prepare a reddish-brown catalyst (Ziegler-Natta) solution. Manufactured.

<Example 3-1 to Example 3-4>

Carry out in the same manner as Examples 1-1 to 1-4, but change [Aluminum Compound-1] to 2.97 g (15.0 mmol) of triisobutyl aluminum (Al(i-Bu) ₃ ) to obtain a reddish-brown product. A catalyst (Ziegler-Natta) solution was prepared.

< Example 4-1 to Example 4-4>

The same method as Examples 1-1 to 1-4 was performed, except that [alcohol] was changed to isobutyl alcohol (i-BuOH) to prepare a red-brown catalyst (Ziegler-Natta) solution.

<Example 5-1 to Example 5-4>

Carry out in the same manner as Examples 1-1 to 1-4, but change [alcohol] to 2-methyl-2-propyl alcohol (t-BuOH) to prepare a red-brown catalyst (Ziegler-Natta) solution. did.

<Example 6-1 to Example 6-4>

The same method as Examples 1-1 to 1-4 was performed, except that [alcohol] was changed to cyclohexanol (CHN) to prepare a reddish-brown catalyst (Ziegler-Natta) solution.

<Comparative Example 1-1 to Comparative Example 1-4>

33 mL (30.0 mmol) of 0.9 M ethyl normal butyl magnesium (BEM, [dialkyl magnesium]) heptane solution was added to a 500 mL flask, followed by 120 mL of normal heptane. While stirring the solution, 2.97 g (15.0 mmol) of triisobutyl aluminum (Al(i-Bu) ₃ , [aluminum compound-1]) was slowly added dropwise. Afterwards, while maintaining the reaction temperature at about 0 ℃ to -30 ℃, normal propyl alcohol (n-PrOH, [alcohol]) was slowly added dropwise in the equivalent amount as shown in Table 1 below, and the reaction was sufficiently carried out for about 4 hours to obtain a concentration of 0.2 M. A transparent magnesium carrier solution was prepared.

30 mL (6.00 mmol) of 0.2 M magnesium support slurry solution ([support]) was administered to a 100 mL flask, and 0.36 mL (0.34 g, 1.20 mmol) of Ti(Oi-Pr) ₄ ([metal compound]) heptane solution was added to the flask. was administered and stirred for more than 4 hours. Afterwards, 24.00 mL (24.00 mmol) of 1.0 M ethyl aluminum dichloride solution (C ₂ H ₅ AlCl ₂ , [aluminum compound-2]) diluted in hexane was added and stirred at room temperature for more than 6 hours to form a brown catalyst (Ziegler-Natta). ) A solution was prepared.

<Comparative Example 2-1 to Comparative Example 2-4>

A catalyst (Ziegler-Natta) solution was prepared in the same manner as Comparative Examples 1-1 to 1-4, except that [Aluminum Compound-1] was changed to triethyl aluminum (AlEt ₃ ).

<Comparative Example 3-1 to Comparative Example 3-4>

A catalyst (Ziegler-Natta) solution was prepared in the same manner as Examples 1-1 to 1-4, except that [alcohol] was changed to n-BuOH.

dialkyl magnesium Aluminum compound-1 Alcohol Example 1-1 A, 1.0 equivalent B, 0.5 equivalent D, 1.0 equivalent Example 1-2 D, 2.0 equivalents Example 1-3 D, 3.0 equivalents Example 1-4 D, 3.5 equivalents Example 2-1 A, 1.0 equivalent B, 0.5 equivalent D, 1.0 equivalent Example 2-2 D, 2.0 equivalents Example 2-3 D, 3.0 equivalents Example 2-4 D, 3.5 equivalents Example 3-1 A, 1.0 equivalent C, 0.5 equivalent D, 1.0 equivalent Example 3-2 D, 2.0 equivalents Example 3-3 D, 3.0 equivalents Example 3-4 D, 3.5 equivalents Example 4-1 A, 1.0 equivalent B, 0.5 equivalent E, 1.0 equivalent Example 4-2 E, 2.0 equivalents Example 4-3 E, 3.0 equivalents Example 4-4 E, 3.5 equivalents Example 5-1 A, 1.0 equivalent B, 0.5 equivalent F, 1.0 equivalent Example 5-2 F, 2.0 equivalents Example 5-3 F, 3.0 equivalents Example 5-4 F, 3.5 equivalents Example 6-1 A, 1.0 equivalent B, 0.5 equivalent G, 1.0 equivalent Example 6-2 G, 2.0 equivalents Example 6-3 G, 3.0 equivalents Example 6-4 G, 3.5 equivalents Comparative Example 1-1 A, 1.0 equivalent C, 0.5 equivalent H, 1.0 equivalent Comparative Example 1-2 H, 2.0 equivalents Comparative Example 1-3 H, 3.0 equivalents Comparative Example 1-4 H, 3.5 equivalents Comparative Example 2-1 A, 1.0 equivalent B, 0.5 equivalent H, 1.0 equivalent Comparative Example 2-2 H, 2.0 equivalents Comparative Example 2-3 H, 3.0 equivalents Comparative Example 2-4 H, 3.5 equivalents Comparative Example 3-1 A, 1.0 equivalent B, 0.5 equivalent I, 1.0 equivalent Comparative Example 3-2 I, 2.0 equivalents Comparative Example 3-3 I, 3.0 equivalents Comparative Example 3-4 I, 3.5 equivalents

1) Dialkyl magnesium

A:BEM

2) Aluminum compound-1

B: _AlEt3 / C: Al(i-Bu) ₃

3) alcohol

D: i-PrOH / E: i-BuOH / F: t-BuOH / G: CHN / H: n-PrOH / I: n-BuOH

carrier metal compounds Aluminum compound-2 Example 1-1
inside
Example 1-4 15.0 equivalent J, 1.0 equivalent L, 5.0 equivalents Example 2-1
inside
Example 2-4 15.0 equivalent K, 1.0 equivalent L, 5.0 equivalents Example 3-1
inside
Example 3-4 15.0 equivalent J, 1.0 equivalent L, 5.0 equivalents Example 4-1
inside
Example 4-4 15.0 equivalent J, 1.0 equivalent L, 5.0 equivalents Example 5-1
inside
Example 5-4 15.0 equivalent J, 1.0 equivalent L, 5.0 equivalents Example 6-1
inside
Example 6-4 15.0 equivalent J, 1.0 equivalent L, 5.0 equivalents Comparative Example 1-1
inside
Comparative Example 1-4 5.0 equivalent J, 1.0 equivalent L, 20.0 equivalent Comparative Example 2-1
inside
Comparative Example 2-4 5.0 equivalent J, 1.0 equivalent L, 20.0 equivalent Comparative Example 3-1
inside
Comparative Example 3-4 15.0 equivalent J, 1.0 equivalent L, 5.0 equivalents

1) Metal compounds

J: Ti(Oi-Pr) ₄ / K: TiCl ₄

2) Aluminum compound-2

L: C ₂ H ₅ AlCl ₂

< Experiment example 1> Low-density copolymer polymerization

An autoclave reactor was filled with 0.5 L of saturated hydrocarbon solvent (methylcyclohexane) under stable anhydrous nitrogen, 0.2 g (0.15 mol) of triethyl aluminum and 100 mL (70 g, 0.7 mol) of triethyl aluminum were added, and the reactor temperature was set to 180°C. After stirring while raising the temperature to ℃, 30 bar of ethylene was introduced into the reactor. Prepared in Example 1-4, Example 2-4, Example 3-4, Example 4-4, Example 5-4, Example 6-4, Comparative Example 1-4 and Comparative Example 3-4 1.7 μmol of one catalyst was diluted with 3 mL of saturated postcarbonization solvent (methylcyclohexane) and transferred to the catalyst port, and the catalyst port was pressurized with 50 bar of anhydrous nitrogen. After the autoclave reactor was saturated with ethylene, the catalyst from the catalyst port was injected into the reactor under isothermal conditions at 180°C, and semi-batch polymerization was performed for 10 minutes while continuously supplying ethylene. Afterwards, the reactor was returned to the discharge port and the solvent was dried to obtain a linear low-density copolymer (linear low-density polyethylene, LLDPE). The yield, catalyst mileage, melting index, and density of the obtained linear low-density polyethylene were measured and are shown in Table 3 below.

At this time, the catalyst mileage was defined as the mass of the produced LLDPE divided by the mass of the catalyst. The melt index was measured at 190°C according to the ASTM D1238 standard, and the density was measured using a density gradient column.

LLDPE yield amount
(g) catalyst mileage
(LLDPE ton/Kg of catalyst) MI
(g/10 min) density
(g/mL) Example 1-4 40.70 22.00 0.86 0.9186 Example 2-4 31.60 17.08 0.52 0.9220 Example 3-4 36.32 19.63 0.70 0.9218 Example 4-4 25.12 13.58 0.60 0.9219 Example 5-4 16.10 8.70 0.81 0.9226 Example 6-4 23.12 12.50 0.52 0.9225 Comparative Example 1-4 10.00 3.79 0.35 0.9227 Comparative Example 3-4 13.85 7.49 0.28 0.9301

Referring to Table 3, it can be seen that the amount of copolymer obtained significantly increases and the catalyst mileage value increases when polymerization is performed using the catalyst prepared in Example compared to the case of polymerization using the catalyst prepared in Comparative Example. You can.

< Experiment example 2> Crystallization elution Crystallization elution fractionation (CEF)

In order to analyze the physical properties of the polymer prepared using the catalyst of Example 1-4 through crystallization elution fractionation (CEF), a TCB (trichlorobenzene) solution was used using POLYMER-CHAR CRYTEX-42 equipment. tested. At this time, commercial product A (Dow company (DOWLEX 2045G), MI: 1.00 g/10 min, density: 0.9200 g/mL) and commercial product B (SK company (FN810), MI: 0.99, density: 0.9198 g/mL) were used. It was prepared and tested as a comparison group. The results are shown in Figure 1.

Through the above experiment, in the CEF spectrum, the polymer prepared using the catalyst of the example had a lower proportion of the high-density region (homopolymer) of about 80 ℃ to 100 ℃ and a low-density region of about 50 ℃ to 80 ℃ compared to the commercial product. It was confirmed that the proportion of (copolymer) was high. Therefore, it can be seen that a low-density copolymer with high elongation can be effectively produced using the catalyst of the example.

< Experiment example 3> Magnesium carrier Shape analysis of solution

In order to analyze the transparency and solubility of the magnesium carrier solution according to the type of alcohol solvent, the shape of each magnesium carrier solution prepared in the above Examples and Comparative Examples was observed and shown in Table 4 below, of which the Examples Magnesium fence prepared in 1-4, Example 3-4, Example 4-4, Example 5-4, Example 6-4, Comparative Example 1-4, Comparative Example 2-4, Comparative Example 3-4 A photograph of the retardant solution was taken and shown in Figure 2.

Alcohol Shape of carrier solution Example 1-1 D, 1.0 equivalent TS Example 1-2 D, 2.0 equivalents OS Example 1-3 D, 3.0 equivalents OS Example 1-4 D, 3.5 equivalents OS Example 3-1 D, 1.0 equivalent TS Example 3-2 D, 2.0 equivalents OS Example 3-3 D, 3.0 equivalents OS Example 3-4 D, 3.5 equivalents OS Example 4-1 E, 1.0 equivalent TS Example 4-2 E, 2.0 equivalents OS Example 4-3 E, 3.0 equivalents OS Example 4-4 E, 3.5 equivalents OS Example 5-1 F, 1.0 equivalent TS Example 5-2 F, 2.0 equivalents OS Example 5-3 F, 3.0 equivalents OS Example 5-4 F, 3.5 equivalents OS Example 6-1 G, 1.0 equivalent TS Example 6-2 G, 2.0 equivalents OS Example 6-3 G, 3.0 equivalents OS Example 6-4 G, 3.5 equivalents OS Comparative Example 1-1 H, 1.0 equivalent TS Comparative Example 1-2 H, 2.0 equivalents TS Comparative Example 1-3 H, 3.0 equivalents TS Comparative Example 1-4 H, 3.5 equivalents TS Comparative Example 2-1 H, 1.0 equivalent TS Comparative Example 2-2 H, 2.0 equivalents TS Comparative Example 2-3 H, 3.0 equivalents TS Comparative Example 2-4 H, 3.5 equivalents TS Comparative Example 3-1 I, 1.0 equivalent TS Comparative Example 3-2 I, 2.0 equivalents TS Comparative Example 3-3 I, 3.0 equivalents TS Comparative Example 3-4 I, 3.5 equivalents TS

TS: Transparent Solution

OS: Opaque Slurry

As can be seen from Table 4 and Figure 2, the magnesium support solution prepared using branched-chain alkyl alcohol and cycloalkyl alcohol as a solvent was observed to be opaque, and the solution prepared using straight-chain alkyl alcohol as a solvent was observed to be opaque. One magnesium carrier solution was observed to be transparent. Through this, it can be seen that the alcohol solvent greatly contributes to the shape of the solution in the preparation of the magnesium carrier solution, especially branched-chain alkyl-substituted alcohols such as isopropyl, isobutyl, and tert-butyl, and cyclohexane. It can be seen that by using an alcohol with the same cyclic alkyl substitution, a magnesium support with highly stabilized physical properties can be prepared, and a Ziegler-Natta catalyst with high low-density copolymer production activity can be prepared using this.

Above, one embodiment has been described in detail through preferred examples and experimental examples, but the scope of one embodiment is not limited to the specific embodiment and should be interpreted in accordance with the attached patent claims.

Claims (19)

Preparing a solution containing a magnesium carrier by adding branched-chain alkyl alcohol or cycloalkyl alcohol to a mixture of dialkyl magnesium and a compound represented by the following formula (1); and
Method for producing a Ziegler-Natta catalyst for polymerization of low-density copolymers comprising adding a metal compound containing titanium (Ti) to a solution containing the magnesium support:
[Formula 1]
R ¹ _x AlCl _{3 -x}
In Formula 1,
_R ¹ is each independently C _1-10 alkyl or C _3-10 cycloalkyl _; and
x is 1 to 3.
According to paragraph 1,
After adding the metal compound, the method for producing a Ziegler-Natta catalyst for low-density copolymer polymerization further comprises the step of adding a compound represented by the following formula (2):
[Formula 2]
R ² _y AlCl _{3 -y}
In Formula 2,
_R ² is each independently C _1-10 alkyl or C _3-10 cycloalkyl _; and
y is 1 to 2.
According to paragraph 1,
Wherein R ¹ is _each independently C _1-6 alkyl or C _3-6 cycloalkyl _.
According to paragraph 1,
A method for producing a Ziegler-Natta catalyst for low-density copolymer polymerization, wherein the branched-chain alkyl alcohol or cycloalkyl alcohol is added in a mole number exceeding 1 times the mole number of the dialkyl magnesium.
According to paragraph 1,
A method for producing a Ziegler-Natta catalyst for low-density copolymer polymerization, wherein the branched-chain alkyl alcohol or cycloalkyl alcohol is added in a mole number exceeding twice the mole number of the compound represented by Formula 1.
According to paragraph 2,
Wherein R ² is _each independently C _1-6 alkyl or C _3-6 cycloalkyl _.
According to paragraph 2,
The compound represented by Formula 2 is EtAlCl ₂ , MeAlCl ₂ , PrAlCl ₂ , BuAlCl ₂ or (C ₂ H ₅ ) _3/2 AlCl _3/2 . Method for producing a Ziegler-Natta catalyst for low-density copolymer polymerization.
According to paragraph 2,
A method for producing a Ziegler-Natta catalyst for low-density copolymer polymerization, wherein the molar ratio of the metal compound and the compound represented by Formula 2 is 1:0.1 to 1:15.
According to paragraph 1,
A method for producing a Ziegler-Natta catalyst for low-density copolymer polymerization, wherein the molar ratio of the metal compound and the magnesium support is 1:5 to 1:30.
According to paragraph 1,
A method for producing a Ziegler-Natta catalyst for polymerization of low-density copolymers, wherein the metal compound further includes a Group IV or Group V metal.
According to paragraph 1,
The metal compound includes TiX ₄ or (R ³ O) _z Ti(X) _4-z ,
In this case, X is a halogen atom, R ³ is each independently C _1-10 alkyl, and z is an integer of 1 _to 4.
According to clause 11,
A method for producing a Ziegler-Natta catalyst for polymerization of low-density copolymers, wherein the metal compound is a mixed metal compound further comprising a compound containing a Group V metal.
According to paragraph 1,
The branched-chain alkyl alcohol is a C _3-10 branched-chain alkyl alcohol. Method for producing a Ziegler-Natta catalyst for polymerization of a low-density copolymer.
According to paragraph 1,
The branched chain alkyl alcohol is one type or a combination of two or more types selected from isopropyl alcohol, isobutyl alcohol, and tert-butyl alcohol. Method for producing a Ziegler-Natta catalyst for low-density copolymer polymerization.
According to paragraph 1,
A method for producing a Ziegler-Natta catalyst for polymerization of a low-density copolymer, wherein the cycloalkyl alcohol is a C _3-10 cycloalkyl alcohol.
According to paragraph 1,
A method for producing a Ziegler-Natta catalyst for polymerization of low-density copolymers, wherein the cycloalkyl alcohol is cyclohexanol.
A Ziegler-Natta catalyst for polymerization of low-density copolymers prepared according to the production method according to any one of claims 1 to 16.
A method for producing a low-density copolymer comprising the step of contacting an olefin monomer with a Ziegler-Natta catalyst for polymerizing a low-density copolymer according to claim 17.
According to clause 18,
The low-density copolymer has a density of 0.91 g/mL to 0.94 g/mL and a melt index of 0.1 g/10 min to 5.0 g/10 min measured according to ASTM D1238.