Catalyst composed of diimine ligand and transition metal as well as preparation method and application of catalyst

Abstract

The invention provides a catalyst composed of a diimine ligand and transition metal and a preparation method and application thereof, and relates to the technical field of catalyst preparation, tridentate diimine ligand is synthesized and constructed through short three steps, and the diimine ligand and the transition metal form a complex to serve as a novel catalyst.The defects in the prior art are overcome, and the catalyst is suitable for industrial production. The catalyst composed of the diimine ligand and the transition metal has the structural characteristics of a diimine catalyst and a salicylaldehyde imine catalyst, not only has certain tolerance to water and oxygen, but also can bear poison of a polar monomer to the catalyst, and promotes copolymerization of ethylene and the polar monomer.

Description

Technical Field

[0001] The invention relates to the technical field of catalyst preparation, and in particular to a catalyst composed of a diimine ligand and a transition metal, and a preparation method and application thereof. Background Art

[0002] The development of polyolefin materials is highly dependent on the development of catalysts. The earliest ZN catalysts could only catalyze polyolefin products with a wide distribution. Metallocene catalysts (such as CGC catalysts, etc.) can produce products with a narrow molecular weight distribution due to the characteristics of a single-center active site, and the catalytic activity is also further improved. The range of polyolefin products has been further broadened. However, the high cost and high water and oxygen sensitivity of metallocene catalysts have always been the difficulties that limit their industrial production. Although some post-metallocene catalysts with lower raw material costs have been developed subsequently, few can be used in industrialization. This is mainly because the synthesis route of post-metallocene catalysts is generally long and difficult to scale up production.

[0003] Although olefin polymerization catalysts have experienced the development of ZN catalysts, metallocene catalysts and post-metallocene catalysts, metallocene catalysts are still the main solution in industry. The lengthy and cumbersome steps in the synthesis of post-metallocene catalysts limit their industrialization. Therefore, in order to develop a post-metallocene catalyst that can be industrially produced, it is necessary not only to consider the performance of the catalyst itself, but also to take into account the simplicity of the synthesis method. Summary of the invention

[0004] In view of the shortcomings of the prior art, the present invention provides a catalyst composed of a diimine ligand and a transition metal, a preparation method and an application thereof. The obtained catalyst not only has a certain tolerance to water and oxygen, but also can withstand the poisoning of polar monomers to the catalyst, thereby promoting the copolymerization of ethylene and polar monomers.

[0005] To achieve the above objectives, the technical solution of the present invention is implemented through the following technical solutions:

[0006] A catalyst composed of a bisimine ligand and a transition metal, wherein the structure of the bisimine ligand is as follows:

[0007]

[0008] The structure of the catalyst is:

[0009]

[0010] Wherein, R is selected from any one of hydrogen, C1-C20 alkyl, C6-C20 aryl, and substituted aryl; M is a Group IVB or Group VIII transition metal; and X is any one of a halogen, a C1-C20 alkane, and other ligand groups.

[0011] The preparation method of the bisimine ligand comprises the following steps:

[0012] S1-1. Synthesis of salicylaldehyde propylene glycol imine: salicylaldehyde and 3-amino-1,2-propylene glycol are dissolved in a solvent, reacted at room temperature overnight, and then washed to obtain a yellow solid product, which is salicylaldehyde propylene glycol imine;

[0013] S1-2, preparation of Ph(OH)CHNCH2CHO: dissolving the salicylaldehyde propylene glycol imine in deionized water to prepare a salicylaldehyde propylene glycol imine solution, and dropping a sodium periodate solution into the salicylaldehyde propylene glycol imine solution, removing the solvent after the reaction in the dark, and dissolving the product with ethanol, and then removing the ethanol to obtain Ph(OH)CHNCH2CHO;

[0014] S1-3. Synthesis of diimine ligand: Disperse the above Ph(OH)CHNCH2CHO in anhydrous ethanol, add p-toluenesulfonic acid, dropwise add amine substances, reflux overnight, filter, and wash with cold methanol to obtain a diimine ligand.

[0015] Preferably, in step S1-1, the molar ratio of salicylaldehyde to 3-amino-1,2-propanediol is 1-2:3-1, and the solvent is anhydrous ethanol.

[0016] Preferably, the molar ratio of the amount of sodium periodate in the sodium periodate solution in step S1-2 to salicylaldehyde propylene glycol imine is 1-2:3-1.

[0017] Preferably, the amine substance in step S1-3 is aniline, 2,6-diisopropylaniline, 4-tert-butylaniline or the like, an amino aromatic ring-containing aliphatic amine.

[0018] Preferably, in step S1-3, the molar ratio of Ph(OH)CHNCH2CHO, p-toluenesulfonic acid and amine substances is 1-2:0.1-0.2:3-1.

[0019] The preparation method of the catalyst comprises the following steps:

[0020] S2-1, dissolving a transition metal salt in methanol to prepare a transition metal salt solution;

[0021] S2-2, under an inert atmosphere, dissolving the bisimine ligand powder in methanol to prepare a ligand solution;

[0022] S2-3. Add the ligand solution dropwise to the transition metal salt solution, react at room temperature for 8 hours, drain the solvent, and wash the solid with ether to obtain the catalyst.

[0023] Preferably, the molar ratio of the diimine ligand to the transition metal salt during the catalyst preparation process is 1-2:3-1.

[0024] The catalyst is used for catalyzing homopolymerization of ethylene, copolymerization with non-polar monomers, and copolymerization of ethylene with polar monomers.

[0025] The present invention provides a catalyst composed of a diimine ligand and a transition metal, which has the following advantages over the prior art:

[0026] (1) The present invention provides an olefin polymerization catalyst with a short synthesis route, green and environmentally friendly synthesis method, low cost, and easy industrial production through structural design and reasonable synthesis route planning. The catalyst not only has ethylene homopolymerization activity, but also can catalyze the copolymerization of ethylene and polar monomers, and the catalytic polymerization performance is not lower than that of the published diimine catalysts and salicylaldehyde imine catalysts. Through a short three-step synthesis, a [O, N, N] tridentate diimine ligand is constructed, and after forming a complex with a late transition metal, it has the structural characteristics of both the diimine catalyst and the salicylaldehyde imine catalyst. It not only has a certain tolerance to water and oxygen, but also can tolerate the poisoning of the polar monomer to the catalyst, and promotes the copolymerization of ethylene and the polar monomer.

[0027] (2) The catalyst structure disclosed in the present invention has a short synthesis route and the synthesis method is easy to implement for scale-up production, which can also reduce the generation of three wastes, is more environmentally friendly, and is conducive to industrial production. DETAILED DESCRIPTION

[0028] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention is clearly and completely described below in combination with the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0029] Embodiment 1:

[0030] Synthesis of catalyst Ph(OH)CHNCH2CHNPhNiCl:

[0031] (1) Synthesis of salicylaldehyde propylene glycol imine

[0032] 10.0 g of salicylaldehyde and 9.0 g of 3-amino-1,2-propanediol were dissolved in 30 mL of anhydrous ethanol and reacted overnight at room temperature to precipitate yellow crystals, which were filtered and washed with cold methanol to obtain 7.2 g of a yellow solid product with a yield of 45.0%.

[0033] 1 H-NMR(D2O)δ8.36(s,1H), 6.5-7.5(m,4H), 3.5-4.2(dd,5H).

[0034] (2) Preparation of Ph(OH)CHNCH2CHO:

[0035] Dissolve 7.2g of salicylaldehyde propylene glycol imine in 10mL of deionized water; dissolve 9.5g of sodium periodate in 10mL of deionized water. Slowly add the sodium periodate solution dropwise and react for 8h in the dark. Remove the solvent and dissolve the product with ethanol. Drain the ethanol to obtain 4.9g of yellow oil with a yield of 82.2%.

[0036] 1 H-NMR(D2O)δ8.54(s,1H), 6.8-7.7(m,4H), 4.5(m,2H).

[0037] (3) Synthesis of ligand

[0038] Disperse 4.9 g Ph(OH)CHNCH2CHO in 25 mL anhydrous ethanol, add 0.1 eq p-toluenesulfonic acid, dropwise add 2.88 g aniline, reflux overnight, filter, wash with cold methanol, and obtain 3.7 g brown-yellow solid, with a yield of 51.7%.

[0039] 1 H-NMR(CD3Cl) δ8.48(m,2H), 6.6-7.8(m,9H), 4.3(m,2H).

[0040] (4) Synthesis of catalyst:

[0041] Under an inert atmosphere, 2.0 g of the above ligand powder was dissolved in methanol; 1.1 g of NiCl2 was dissolved in methanol, and the ligand solution was added dropwise to the nickel chloride solution, and the reaction was carried out at room temperature for 8 h. The solvent was drained, and the solid was washed with ether to obtain 2.5 g of solid as catalyst 1, with a yield of 91.3%.

[0042] 1 H-NMR(CD3Cl) δ8.42(m,2H), 6.6-7.8(m,9H), 4.2(m,2H).

[0043] And the specific synthetic route is:

[0044]

[0045] Embodiment 2:

[0046] Synthesis of catalyst Ph(OH)CHNCH2CHNPh(ipr)2NiCl (where ipr is isopropyl):

[0047] (1) Synthesis of salicylaldehyde propylene glycol imine

[0048] 10.0 g of salicylaldehyde and 9.0 g of 3-amino-1,2-propanediol were dissolved in 30 mL of anhydrous ethanol and reacted overnight at room temperature to precipitate yellow crystals, which were filtered and washed with cold methanol to obtain 7.2 g of a yellow solid product with a yield of 45.0%.

[0049] 1 H-NMR(D2O)δ8.36(s,1H), 6.5-7.5(m,4H), 3.5-4.2(dd,5H).

[0050] (2) Preparation of Ph(OH)CHNCH2CHO

[0051] Dissolve 7.2g of salicylaldehyde propylene glycol imine in 10mL of deionized water. Dissolve 9.5g of sodium periodate in 10mL of deionized water. Slowly drop the sodium periodate solution and react for 8h in the dark. Remove the solvent and dissolve the product with ethanol. Drain the ethanol to obtain 4.9g of yellow oil. Yield 82.2%.

[0052] 1 H-NMR(D2O)δ8.54(s,1H), 6.8-7.7(m,4H), 4.5(m,2H).

[0053] (3) Synthesis of ligand

[0054] Disperse 4.9 g Ph(OH)CHNCH2CHO in 25 mL anhydrous ethanol, add 0.1 eq p-toluenesulfonic acid, dropwise add 5.48 g 2,6-diisopropylaniline, reflux overnight, filter, wash with cold methanol, and obtain 4.2 g brown-yellow solid. Yield 43.4%.

[0055] 1 H-NMR(CD3Cl) δ8.48(m,2H), 6.6-7.8(m,9H), 4.3(m,2H).

[0056] (4) Catalyst synthesis

[0057] Under an inert atmosphere, 2.0 g of ligand powder was dissolved in methanol; 1.0 g of NiCl2 was dissolved in methanol, and the ligand solution was added dropwise to the nickel chloride solution, and the reaction was carried out at room temperature for 8 hours. The solvent was drained, and the solid was washed with ether to obtain 2.3 g of solid as catalyst 2, with a yield of 82.1%.

[0058] 1 H-NMR(CD3Cl) δ8.42(m,2H), 6.6-7.8(m,9H), 4.2(m,2H).

[0059] Embodiment 3:

[0060] Synthesis of catalyst Ph(OH)CHNCH2CHNPh(tBu)NiCl (where tBu is tert-butyl):

[0061] (1) Synthesis of salicylaldehyde propylene glycol imine

[0062] 10.0 g of salicylaldehyde and 9.0 g of 3-amino-1,2-propanediol were dissolved in 30 mL of anhydrous ethanol and reacted overnight at room temperature to precipitate yellow crystals, which were filtered and washed with cold methanol to obtain 7.2 g of a yellow solid product with a yield of 45.0%.

[0063] 1 H-NMR(D2O)δ8.36(s,1H), 6.5-7.5(m,4H), 3.5-4.2(dd,5H).

[0064] (2)Ph(OH)CHNCH2CHO

[0065] Dissolve 7.2g of salicylaldehyde propylene glycol imine in 10mL of deionized water. Dissolve 9.5g of sodium periodate in 10mL of deionized water. Slowly drop the sodium periodate solution and react for 8h in the dark. Remove the solvent and dissolve the product with ethanol. Drain the ethanol to obtain 4.9g of yellow oil. Yield 82.2%.

[0066] 1 H-NMR(D2O)δ8.54(s,1H), 6.8-7.7(m,4H), 4.5(m,2H).

[0067] (3) Synthesis of ligand

[0068] Disperse 4.9 g Ph(OH)CHNCH2CHO in 25 mL anhydrous ethanol, add 0.1 eq p-toluenesulfonic acid, dropwise add 5.48 g 4-tert-butylaniline, reflux overnight, filter, wash with cold methanol, and obtain 3.1 g solid. Yield: 35.0%.

[0069] 1 H-NMR(CD3Cl) δ8.48(m,2H), 6.6-7.8(m,9H), 4.3(m,2H).

[0070] (4) Catalyst synthesis

[0071] Under an inert atmosphere, 2.0 g of ligand powder was dissolved in methanol; 1.1 g of NiCl2 was dissolved in methanol, and the ligand solution was added dropwise to the nickel chloride solution, and the reaction was carried out at room temperature for 8 h. The solvent was drained, and the solid was washed with ether to obtain 1.8 g of solid as catalyst 3, with a yield of 62.5%.

[0072] 1H-NMR(CD3Cl) δ8.42(m,2H), 6.6-7.8(m,9H), 4.2(m,2H).

[0073] Detection:

[0074] Ethylene / norbornene copolymerization

[0075] After purging the reactor with hot nitrogen for 48h, ethylene gas was introduced and the pressure was stabilized at 5.0bar. 150mL methylcyclohexane and 120mL 1-octene were added, 15μmol catalyst and 500 times modified methylaluminoxane (MMAO) were injected respectively, the temperature was raised to 50°C, and the reaction was carried out for 20min. The product was precipitated with ethanol and dried. (The diimine catalyst and salicylaldehyde imine catalyst are information provided in the literature Journal of the American Chemical Society 1995 117 (23), 6414-6415 DOI: 10.1021 / ja00128a054 and US Patent 5332708, 1994) The specific polymer catalysis data results are shown in the following table:

[0076]

[0077]

[0078] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features may be replaced by equivalents. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A catalyst composed of a diimine ligand and a transition metal, characterized in that: The structure of the bisimine ligand is as follows: The structure of the catalyst is: Wherein, R is selected from any one of hydrogen, C1-C20 alkyl, C6-C20 aryl, and substituted aryl; M is a Group IVB or Group VIII transition metal; and X is any one of a halogen, a C1-C20 alkane, and other ligand groups.

2. A catalyst as claimed in claim 1, characterized in that: The preparation method of the bisimine ligand comprises the following steps: S1-1. Synthesis of salicylaldehyde propylene glycol imine: salicylaldehyde and 3-amino-1,2-propylene glycol are dissolved in a solvent, reacted at room temperature overnight, and then washed to obtain a yellow solid product, which is salicylaldehyde propylene glycol imine; S1-2, preparation of Ph(OH)CHNCH2CHO: dissolving the salicylaldehyde propylene glycol imine in deionized water to prepare a salicylaldehyde propylene glycol imine solution, and dropping a sodium periodate solution into the salicylaldehyde propylene glycol imine solution, removing the solvent after the reaction in the dark, and dissolving the product with ethanol, and then removing the ethanol to obtain Ph(OH)CHNCH2CHO; S1-3. Synthesis of diimine ligand: Disperse the above Ph(OH)CHNCH2CHO in anhydrous ethanol, add p-toluenesulfonic acid, dropwise add amine substances, reflux overnight, filter, and wash with cold methanol to obtain a diimine ligand.

3. The preparation method according to claim 2, characterized in that: In the step S1-1, the molar ratio of salicylaldehyde to 3-amino-1,2-propanediol is 1-2:3-1, and the solvent is anhydrous ethanol.

4. The preparation method according to claim 2, characterized in that: In the step S1-2, the molar ratio of the amount of sodium periodate in the sodium periodate solution to the amount of salicylaldehyde propylene glycol imine is 1-2:3-1.

5. The preparation method according to claim 2, characterized in that: The amine substance in step S1-3 is any one of an amino aromatic ring and an aliphatic amine.

6. The preparation method according to claim 2, characterized in that: The amine substance is any one of aniline, 2,6-diisopropylaniline or 4-tert-butylaniline.

7. The preparation method according to claim 2, characterized in that: In the step S1-3, the molar ratio of Ph(OH)CHNCH2CHO, p-toluenesulfonic acid and amine substances is 1-2:0.1-0.2:3-1.

8. A method for preparing the catalyst according to claim 1, characterized in that: The preparation method of the catalyst comprises the following steps: S2-1, dissolving a transition metal salt in methanol to prepare a transition metal salt solution; S2-2, under an inert atmosphere, dissolving the bisimine ligand powder in methanol to prepare a ligand solution; S2-3. Add the ligand solution dropwise to the transition metal salt solution, react at room temperature for 8 hours, drain the solvent, and wash the solid with ether to obtain the catalyst.

9. The preparation method according to claim 8, characterized in that: In the catalyst preparation process, the molar ratio of the diimine ligand to the transition metal salt is 1-2:3-1.

10. A catalyst as claimed in claim 1, characterized in that: The catalyst is used for catalyzing the homopolymerization of ethylene, the copolymerization of ethylene with non-polar monomers, and the copolymerization of ethylene with polar monomers.

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