CN101704910B - A kind of transition metal olefin polymerization catalyst and preparation method thereof - Google Patents

Abstract

The invention relates to a transition metal olefin polymerization catalyst and a preparation method thereof; the catalyst includes (A) a transition metal compound of the general formula (I) and (B) an organoaluminoxane compound, wherein the transition metal compound of the general formula (I) M is a transition metal atom of Group IVB in the periodic table of elements, m is an integer between 1 and 6, R ₁ to R ₆ are H, halogen, hydrocarbon group, etc., n is a number that satisfies the valence of M, and X is Halogen, hydrocarbon group, etc., the catalyst has high activity in catalyzing the polymerization of olefins (ethylene, propylene), and has excellent structure adjustability, and the activity of the catalyst can be regulated by adjusting the ligand structure and the type of transition metal.

(Formula I)

Description

A kind of transition metal olefin polymerization catalyst and preparation method thereof

technical field

The invention relates to a transition metal olefin polymerization catalyst and a preparation method thereof.

Background technique

The key to the development of polyolefin industry lies in polyolefin catalysts. The emergence of each new type of catalyst will bring about changes in new polymerization processes and the development of new polyolefin materials. In the early 1950s, Ziegler and Natta successively used TiCl ₄ -AlEt ₃ catalyst system to synthesize high-density polyethylene and TiCl ₃ -AlEt ₂ Cl catalyst system to synthesize isotactic polypropylene, opening up a new era of polyolefin industry. In the early 1980s, Kaminsky and Sinn discovered a new type of polyolefin catalytic system with methylaluminoxane as the cocatalyst and metallocene as the main catalyst, which can not only prepare high-density polyethylene, linear low-density polyethylene, isotopic Stereotactic polypropylene, and can synthesize syndiotactic polypropylene, syndiotactic polystyrene and other products that are difficult to synthesize with traditional catalysts. In 1995, Brookhart et al. first reported the late transition metal catalysts of diimine ligands, which further promoted the development of olefin polymerization catalysts. A series of non-metallocene catalysts such as salicylaldimine type late transition metal catalysts, containing P and O ligands SHOP-type late transition metal catalysts and phenoxyimine-type early transition metal catalysts have been developed, especially the phenoxyimine-type early transition metal catalysts recently studied by Mitsui Chemicals, that is, FI catalysts, which exhibit very high alkene Polymerization catalytic activity, and the ability to prepare some high value-added polyolefin materials by adjusting the ligand structure and transition metal species has attracted great attention. However, the patents of FI catalysts are almost covered by foreign companies, so it is of great significance to develop new high-activity non-metallocene olefin polymerization catalysts.

Contents of the invention

The object of the present invention is to provide a kind of early transition metal olefin polymerization catalyst and preparation method thereof with phenol nitrone as ligand.

The olefin polymerization catalyst provided by the present invention includes (A) a transition metal compound with the general formula (I) and (B) an organometallic compound, an organoaluminoxane compound or an ionizable compound. Wherein A is a transition metal compound represented by general formula (I),

In the formula: M is a transition metal atom in Group IVB of the Periodic Table of Elements; m is an integer from 1 to 6; R ₁ to R ₆ can be the same or different, and they are hydrogen atoms, halogen atoms, hydrocarbon groups, heterocyclic compounds Residue, oxygen-containing group, nitrogen-containing group, boron-containing group, sulfur-containing group, phosphorus-containing group, silicon-containing group, germanium-containing group, tin-containing group, hydrocarbon-substituted silyl group, hydrocarbon-substituted silyloxy group, Alkoxy, alkylthio, aryloxy, arylthio, acyl, ester, thioester, amido, imide, amino, imino, sulfoester, sulfonylamino, cyano or nitro, and two or more groups among them can be combined with each other to form a ring, and when m is 2 or more, any two groups represented by R ₁ to R ₆ can be combined.

n is a number that satisfies the valence state;

X is a hydrogen atom, a halogen atom, a hydrocarbon group, an oxygen-containing group, a sulfur-containing group, a boron-containing group, an aluminum-containing group, a phosphorus-containing group, a halogen-containing group, a heterocyclic compound residue, a silicon-containing group, a germanium-containing group or a tin-containing group When n is 2 or more, multiple X groups can be the same or different, and can be combined with each other to form a ring;

(B) is an organoaluminoxane compound.

The Al/M ratio of the transition metal compound A and the organoaluminoxane compound B described in the present invention is 10-10000:1.

The olefin polymerization catalyst system composed of transition metal compound A and organoaluminoxane compound B is used for olefin solvent polymerization, and the white polyolefin powder is prepared by polymerization at 0-200°C and 0.1-1MPa for 5min to 180min.

Another object of the present invention is to provide a method for preparing a transition metal catalyst using phenolic nitrone as a ligand.

The transition metal compound A of the olefin polymerization catalyst of the present invention is prepared according to the following steps: the phenolic nitrone ligand containing active hydrogen is stripped of the active hydrogen atom under the action of an organic lithium salt (such as n-butyllithium) or sodium hydride, Sodium or lithium salts of the ligands are generated. The lithium salt or sodium salt of the ligand is reacted with the precursor compound of the transition metal of the fourth group to obtain an organometallic compound.

The specific reaction process is as follows: under the _N2 protection condition, slowly add the tetrahydrofuran solution of the phenolic nitrone ligand to the tetrahydrofuran solution of NaH or n-butyl lithium dropwise, the molar amount of the phenolic nitrone ligand and NaH or n-butyl lithium The ratio is 1:1-10; the reaction is 2-24 hours at 0°C-100°C. Unreacted starting material was removed by centrifugation. Under the condition of -100°C to 0°C, slowly drop the sodium salt or lithium salt of phenolnitrone obtained after proton stripping into the tetrahydrofuran solution of the precursor compound of the transition metal of group IV, and react for 2 to 24 hours. The solvent was removed in vacuo, dichloromethane was added dropwise, NaCl was removed by centrifugation to give a clear solution of transition metal compound A in dichloromethane, the dichloromethane was then removed in vacuo, and the catalyst was washed with hexane. Vacuum drying at 50°C for 1-10 hours to obtain transition metal compound A powder.

All solvents used in this method must be anhydrous and oxygen-free.

The precursor compounds used in the present invention are mainly ZrCl ₄ , TiCl ₄ and HfCl ₄ .

The Al/Zr ratio of the transition metal compound and the cocatalyst in the catalyst is 100-10000:1.

The Al/Ti ratio of the transition metal compound and the cocatalyst in the catalyst is 10-10000:1.

The organoaluminoxane compound is triethylaluminum, triisobutylaluminum, methylaluminoxane, and the catalyzed olefins are mainly ethylene and propylene.

The olefin polymerization catalyst system designed in the present invention has high polymerization activity and excellent structure adjustability, and the activity of the catalyst can be regulated by adjusting the ligand structure and the type of transition metal.

Description of drawings

The ¹ H-NMR spectrogram of the procatalyst A prepared in Fig. 1 embodiment 1;

Detailed ways

Example 1

1 Preparation of main catalyst A

A dry three-neck flask equipped with a dropping funnel and a magnet was evacuated and filled with nitrogen. The tetrahydrofuran solution of ligand 1 was slowly added dropwise to the excess NaH suspension in tetrahydrofuran. Stir at room temperature for 5 hours. Transfer the reaction solution to a test tube with a branched tube. Centrifuge for half an hour. Under low temperature conditions, the supernatant layer was slowly added dropwise into the tetrahydrofuran solution of ZrCl ₄ (THF) ₂ with a catheter. React at room temperature for 24 hours. The solvent was removed in vacuo to give the crude product. Add 10 mL of dichloromethane and stir to dissolve. Centrifuge and transfer the supernatant. Concentrate to give a yellow solid. Add 4 ml of hexane each time for three washes. The solid was dried at 50°C for 8 hours.

2 Solvent Polymerization of Olefins

The polymerization flask, which was dried at 130°C for 5 hours, was fitted with magnets and dried under vacuum for one hour. Add 50ml of dry toluene and a certain amount of MAO solution (Al/Zr=2000), and stir at 30°C until the solution absorbs ethylene to reach saturation, then add 5ml of catalyst in toluene solution (2μ/ml) with a syringe, and the polymerization reaction begins. After 30 min of reaction, the polymerization reaction was terminated with 10% acidified ethanol. After the polymer was washed with water and ethanol, it was dried at 60°C to constant weight.

Example 2

1 Preparation of main catalyst A

The preparation of the main catalyst is the same

2 solvent polymerization

The polymerization condition operation is the same as 1, and Al/Zr is changed to 3000.

Example 3

1 Preparation of main catalyst A

The preparation of the main catalyst is the same

2 solvent polymerization

The polymerization conditions are the same as in 1, and the co-catalyst is changed to TEA.

Example 4

1 Preparation of main catalyst A

The preparation of the main catalyst is the same

2 solvent polymerization

Polymerization conditions are the same as 1, with ethylene gas replaced by propylene gas.

Example 5

1 Preparation of main catalyst A

Catalyst preparation same

2 solvent polymerization

A 500ml high-pressure polymerization kettle was vacuum-dried at 70°C for two hours. Add 100ml of dry toluene, a certain amount of MAO solution (Al/Zr=2000), and stir at 30°C until the solution absorbs ethylene to reach saturation, then add 2ml of catalyst in toluene solution (1μ/ml) with a syringe, and the polymerization reaction begins. After 30 min of reaction, the polymerization reaction was terminated with 10% acidified ethanol. After the polymer was washed with water and ethanol, it was dried at 60°C to constant weight.

Example 6

1 Preparation of main catalyst A

Catalyst preparation same

2 solvent polymerization

The polymerization conditions are the same as five, and the reaction temperature is 60°C.

Example 7

Preparation of main catalyst A

A dry three-neck flask equipped with a dropping funnel and a magnet was evacuated and filled with nitrogen. The tetrahydrofuran solution of ligand 1 was slowly added dropwise to the excess NaH suspension in tetrahydrofuran. Stir at room temperature for 5 hours. Transfer the reaction solution to a test tube with a branched tube. Centrifuge for half an hour. The supernatant was slowly added dropwise into the hexane solution of TiCl ₄ using a catheter. React at room temperature for 24 hours. The solvent was removed in vacuo to give the crude product. Add 10ml of dichloromethane, stir to dissolve. Centrifuge and transfer the supernatant. Concentration to dryness gave a red solid. Add 4ml of hexane each time for three washes. The solid was dried at 50°C for 8 hours.

Example 8

Preparation of main catalyst A

A dry three-neck flask equipped with a dropping funnel and a magnet was evacuated and filled with nitrogen. The tetrahydrofuran solution of Ligand 1 was slowly added dropwise to the tetrahydrofuran suspension of n-butyllithium, and stirred in an ice-water bath for 5 hours. Transfer the reaction solution to a test tube with a branched tube. Centrifuge for half an hour. The supernatant was slowly added dropwise into the hexane solution of TiCl ₄ using a catheter. React at -68°C for 24 hours. The solvent was removed in vacuo to give the crude product. Add 10ml of dichloromethane, stir to dissolve. Centrifuge and transfer the supernatant. Concentration to dryness gave a red solid. Add 4ml of hexane each time for three washes. The solid was dried at 50°C for 8 hours.

Example 9

Preparation of main catalyst A

A dry three-neck flask equipped with a dropping funnel and a magnet was evacuated and filled with nitrogen. The tetrahydrofuran solution of Ligand 1 was slowly added dropwise to the tetrahydrofuran suspension of n-butyllithium, and stirred in an ice-water bath for 5 hours. Transfer the reaction solution to a test tube with a branched tube. Centrifuge for half an hour. The supernatant was slowly added dropwise into the hexane solution of TiCl ₄ using a catheter. React at -68°C for 24 hours. The solvent was removed in vacuo to give the crude product. Add 10ml of dichloromethane, stir to dissolve. Centrifuge and transfer the supernatant. Concentration to dryness gave a red solid. Red crystals were obtained by recrystallization from a mixed solution of dichloromethane and hexane.

Example 10

Preparation of main catalyst A

A dry three-neck flask equipped with a dropping funnel and a magnet was evacuated and filled with nitrogen. The tetrahydrofuran solution of ligand 2 was slowly added dropwise to the excess NaH suspension in tetrahydrofuran. Stir at room temperature for 5 hours. Transfer the reaction solution to a test tube with a branched tube. Centrifuge for half an hour. The supernatant was slowly added dropwise into ZrCl ₄ (THF) ₂ with a catheter. React at room temperature for 24 hours. The solvent was removed in vacuo to give the crude product. Add 10ml of dichloromethane, stir to dissolve. Centrifuge and transfer the supernatant. Concentration to dryness afforded a yellow solid. Add 4ml of hexane each time for three washes. The solid was dried at 50°C for 8 hours.

Example 11

Preparation of main catalyst A

A dry three-neck flask equipped with a dropping funnel and a magnet was evacuated and filled with nitrogen. The tetrahydrofuran solution of ligand 3 was slowly added dropwise to the excess NaH suspension in tetrahydrofuran. Stir at room temperature for 5 hours. Transfer the reaction solution to a test tube with a branched tube. Centrifuge for half an hour. The supernatant was slowly added dropwise into ZrCl ₄ (THF) ₂ with a catheter. React at room temperature for 24 hours. The solvent was removed in vacuo to give the crude product. Add 10ml of dichloromethane, stir to dissolve. Centrifuge and transfer the supernatant. Concentration to dryness afforded a yellow solid. Add 4ml of hexane each time for three washes. The solid was dried at 50°C for 8 hours.

Example 12

Preparation of main catalyst A

A dry three-neck flask equipped with a dropping funnel and a magnet was evacuated and filled with nitrogen. The tetrahydrofuran solution of ligand 4 was slowly added dropwise to the excess NaH suspension in tetrahydrofuran. Stir at room temperature for 5 hours. Transfer the reaction solution to a test tube with a branched tube. Centrifuge for half an hour. The supernatant was slowly added dropwise into ZrCl ₄ (THF) ₂ with a catheter. React at room temperature for 24 hours. The solvent was removed in vacuo to give the crude product. Add 10ml of dichloromethane, stir to dissolve. Centrifuge and transfer the supernatant. Concentration to dryness afforded a yellow solid. Add 4ml of hexane each time for three washes. The solid was dried at 50°C for 8 hours.

Example 13

Preparation of main catalyst A

A dry three-neck flask equipped with a dropping funnel and a magnet was evacuated and filled with nitrogen. The tetrahydrofuran solution of ligand 5 was slowly added dropwise to the excess NaH suspension in tetrahydrofuran. Stir at room temperature for 5 hours. Transfer the reaction solution to a test tube with a branched tube. Centrifuge for half an hour. The supernatant was slowly added dropwise into ZrCl ₄ (THF) ₂ with a catheter. React at room temperature for 24 hours. The solvent was removed in vacuo to give the crude product. Add 10ml of dichloromethane, stir to dissolve. Centrifuge and transfer the supernatant. Concentration to dryness afforded a yellow solid. Add 4ml of hexane each time for three washes. The solid was dried at 50°C for 8 hours.

Example 14

Preparation of main catalyst A

A dry three-neck flask equipped with a dropping funnel and a magnet was evacuated and filled with nitrogen. The tetrahydrofuran solution of ligand 6 was slowly added dropwise to the excess NaH suspension in tetrahydrofuran. Stir at room temperature for 5 hours. Transfer the reaction solution to a test tube with a branched tube. Centrifuge for half an hour. The supernatant was slowly added dropwise into ZrCl ₄ (THF) ₂ with a catheter. React at room temperature for 24 hours. The solvent was removed in vacuo to give the crude product. Add 10ml of dichloromethane, stir to dissolve. Centrifuge and transfer the supernatant. Concentration to dryness afforded a yellow solid. Add 4ml of hexane each time for three washes. The solid was dried at 50°C for 8 hours.

Example 15

Preparation of main catalyst A

A dry three-neck flask equipped with a dropping funnel and a magnet was evacuated and filled with nitrogen. The tetrahydrofuran solution of ligand 7 was slowly added dropwise to the excess NaH suspension in tetrahydrofuran. Stir at room temperature for 5 hours. Transfer the reaction solution to a test tube with a branched tube. Centrifuge for half an hour. The supernatant was slowly added dropwise into ZrCl ₄ (THF) ₂ with a catheter. React at room temperature for 24 hours. The solvent was removed in vacuo to give the crude product. Add 10ml of dichloromethane, stir to dissolve. Centrifuge and transfer the supernatant. Concentration to dryness afforded a yellow solid. Add 4ml of hexane each time for three washes. The solid was dried at 50°C for 8 hours.

Example 16

Preparation of main catalyst A

A dry three-neck flask equipped with a dropping funnel and a magnet was evacuated and filled with nitrogen. The tetrahydrofuran solution of ligand 8 was slowly added dropwise to the excess NaH suspension in tetrahydrofuran. Stir at room temperature for 5 hours. Transfer the reaction solution to a test tube with a branched tube. Centrifuge for half an hour. The supernatant was slowly added dropwise into ZrCl ₄ (THF) ₂ with a catheter. React at room temperature for 24 hours. The solvent was removed in vacuo to give the crude product. Add 10ml of dichloromethane, stir to dissolve. Centrifuge and transfer the supernatant. Concentration to dryness afforded a yellow solid. Add 4ml of hexane each time for three washes. The solid was dried at 50°C for 8 hours.

Table 1. Experimental results of C ₂₁ H ₂₆ NO ₂ ZrCl ₂ /MAO catalytic polymerization

Table 2 Ligand structure diagram

Claims (9)

1. transition metal catalyst for olefin polymerization is characterized in that:

This catalyzer comprises that general formula is the transistion metal compound and the Organoaluminoxy hydride compounds of (I); Logical formula I:

In the formula: M is the transition metal atoms in the periodic table of elements IV B family;

M is the integer of 1-6;

R ₁-R ₆Can be identical or different, and be respectively hydrogen atom, halogen atom, alkyl, heterogeneous ring compound residue, contain oxygen base, nitrogenous base, contain boryl, contain sulfenyl, phosphorous-containigroups groups, contain silica-based, germanic base, contain tinbase, and a plurality of groups can be incorporated into ring in them, when m is 2 or when bigger, any two by R ₁-R ₆The expression group can in conjunction with;

N is a number that satisfies valence state;

X is hydrogen atom, halogen atom, alkyl, contain the oxygen base, contain sulfenyl, contain boryl, contain aluminium base, phosphorous-containigroups groups, contain halogen, heterogeneous ring compound residue, contain silica-based, germanic base or contain tinbase, when n is 2 or when bigger, a plurality of X bases can be identical or different, and can be incorporated into ring.

2. a kind of transition metal catalyst for olefin polymerization according to claim 1 is characterized in that: described transition metal atoms is Zr; Transistion metal compound is 100～10000: 1 with the Al/Zr ratio of Organoaluminoxy hydride compounds.

3. a kind of transition metal catalyst for olefin polymerization according to claim 1 is characterized in that: described transition metal atoms is Ti; Transistion metal compound is 10～10000: 1 with the Al/Ti ratio of Organoaluminoxy hydride compounds.

4. a kind of transition metal catalyst for olefin polymerization according to claim 1 is characterized in that: described Organoaluminoxy hydride compounds is a methylaluminoxane.

5. the preparation method of a kind of transition metal catalyst for olefin polymerization according to claim 1 is characterized in that: general formula is as follows for the preparation method of the transistion metal compound of (I):

(1) at N ₂Under the protective condition, the tetrahydrofuran solution of phenol nitrone ligand slowly is added drop-wise in the tetrahydrofuran solution of NaH or n-Butyl Lithium, under 0 ℃～100 ℃ conditions, reacted 2～24 hours, the mol ratio of phenol nitrone ligand and NaH or n-Butyl Lithium is 1: 1～10;

(2) centrifugally remove unreacted raw material, under-100 ℃ to 50 ℃ conditions, in the sodium salt of the phenol nitrone that obtains after proton peeled off or the tetrahydrofuran solution of the precursor compound that lithium salts slowly is added drop-wise to the 4th group 4 transition metal, the mol ratio of phenol nitrone ligand and transition metal is 0.1～10,0 ℃ to 100 ℃ reactions 2～24 hours;

(3) vacuum is removed tetrahydrofuran (THF) and is obtained crude product, drip dichloromethane, and the centrifugal NaCl of removing obtains the dichloromethane solution of clarifying transistion metal compound A, removes methylene dichloride with final vacuum;

(4) transistion metal compound for preparing is carried out purifying; Behind the purifying, 0 ℃～100 ℃ following vacuum-dryings obtained the transistion metal compound powder in 1～10 hour.

6. the preparation method of a kind of transition metal alkene catalyst according to claim 5 is characterized in that: the mol ratio of phenol nitrone ligand and transition metal is 0.5～6.

7. the preparation method of a kind of transition metal catalyst for olefin polymerization according to claim 5, it is characterized in that: sodium salt that the phenol nitrone ligand obtains or lithium salts must slowly be added drop-wise in the precursor compound of transistion metal compound, the dropping time was controlled at 5min to 5 hour, and dropping temperature is controlled at-100 ℃ to 50 ℃.

8. the preparation method of a kind of transition metal catalyst for olefin polymerization according to claim 5, it is characterized in that: it is 20 ℃ to 50 ℃ that the temperature of reaction of phenol nitrone ligand and NaH or n-Butyl Lithium is controlled at, 5～15 hours.

9. the preparation method of a kind of transition metal catalyst for olefin polymerization according to claim 5 is characterized in that: the purification process of transistion metal compound is for hexane wash three times or recrystallization; The used solvent of recrystallization is toluene, methylene dichloride, hexane or tetrahydrofuran (THF).

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