CN115246892B

CN115246892B - Single-active-site catalyst, composite catalyst containing single-active-site catalyst, and preparation method and application of single-active-site catalyst

Info

Publication number: CN115246892B
Application number: CN202110458482.5A
Authority: CN
Inventors: 李秉毅; 高榕; 苟清强; 梁迎迎; 李昕阳; 寇鹏; 马永华; 黄廷杰
Original assignee: Sinopec Beijing Research Institute of Chemical Industry; China Petroleum and Chemical Corp
Current assignee: Sinopec Beijing Research Institute of Chemical Industry; China Petroleum and Chemical Corp
Priority date: 2021-04-27
Filing date: 2021-04-27
Publication date: 2023-09-08
Anticipated expiration: 2041-04-27
Also published as: CN115246892A

Abstract

The invention discloses a single-site catalyst, a composite catalyst containing the single-site catalyst, a preparation method and application thereof, wherein the single-site catalyst comprises the following components: a single-site compound, an inorganic carrier, a carrier modifier, and an organoaluminum compound, and/or a reaction product, wherein the single-site compound is selected from at least one of the compounds represented by formula I:

Description

Single-active-site catalyst, composite catalyst containing single-active-site catalyst, and preparation method and application of single-active-site catalyst

Technical Field

The invention belongs to the field of catalysts, and particularly relates to a single-site catalyst, in particular to a single-site catalyst, a composite catalyst containing the single-site catalyst, and a preparation method and application of the composite catalyst.

Background

The low-density polyethylene is the lightest variety in polyethylene resin, has good softness, extensibility, electrical insulation, transparency, easy processing property and certain air permeability, and has better chemical stability, alkali resistance and general primary solvent resistance.

The low density polyethylene is characterized by the following points: the film (1) is slightly milky transparent and soft. The strength is smaller than that of high-density polyethylene, and the impact strength is larger than that of high-density polyethylene. (2) cold resistance, low temperature resistance and higher temperature resistance. The thicker film can bear the sterilization process of soaking in hot water at 90 ℃. (3) Has better moisture resistance, stable chemical property and is insoluble in common solvents. (4) Has high air permeability, so that the storage period of the content is not excessively long when the packaging material is used as easily oxidized food packaging. (5) poor resistance to grease, the product can be slowly swelled. When the oil-containing food is packed, the food can have a rancid taste after long-term storage. (6) Aging occurs due to the action of ultraviolet light and heat for a long time, and the physical properties and dielectric properties of the material are affected. (7 melting point 110-115 deg.C, processing temperature 150-210 deg.C, if in inert gas, the temperature can reach 300 deg.C, but the melt and oxygen contact are easy to degrade.

As the density of polyethylene decreases, the solubility of polyethylene in solvents increases substantially, resulting in linear low density polyethylene that cannot be produced by slurry processes but can be produced by gas phase or solution polymerization processes. However, the solution polymerization process has harsh conditions and high cost, and no very stable solution polymerization process device is operated at home. At present, a large number of gas phase polymerization process devices are in China and are mainly used for producing linear low-density polyethylene.

In the gas phase polymerization process, when the traditional high-activity titanium catalyst is adopted, when the production of the lower density resin is carried out, powder is sticky, and is easy to agglomerate and adhere to the wall, so that the production cannot be stably carried out for a long time, and even when the treatment is improper, malignant production accidents such as bursting and aggregation can occur. The metallocene catalyst can be used for producing products with lower density through loading treatment, but after the metallocene catalyst is loaded conventionally, the catalytic activity is greatly reduced, meanwhile, the metallocene catalyst is very sensitive to hydrogen due to the characteristics of the metallocene catalyst, the device needs to be subjected to targeted transformation, and the process operation difficulty is high.

And other single-site transition metal catalysts cannot be used in the existing process device without being loaded. The usual loading is to select a porous carrier to physically adsorb the catalyst component on the surface of the pore canal. The load is very limited, so that the activity is low, only a few small-scale researches can be carried out, and no practical industrial application is reported.

The proper reduction of the polymerization temperature can improve the stickiness of the low-density PE powder, but if the polymerization temperature is reduced too much, the polymerization activity of the traditional catalyst is obviously reduced, the heat removal capacity of the reactor is limited, the production load is greatly reduced, and the economical efficiency of the operation of the device is directly affected.

Disclosure of Invention

In order to overcome the problems in the prior art, the invention provides a single-site catalyst, a composite catalyst containing the single-site catalyst, a preparation method and application thereof, and the catalyst has the advantages of simple preparation, good particle morphology, better polymerization activity especially at a lower polymerization temperature (70-80 ℃), direct industrial production scale acquisition, direct use on a gas-phase polymerization process device, no equipment transformation of the device, better catalytic activity and milder use condition compared with the common supported catalyst.

It is an object of the present invention to provide a single site catalyst comprising: a single-site compound, an inorganic carrier, a carrier modifier, and an organoaluminum compound, and/or a reaction product, wherein the single-site compound is selected from at least one of the compounds represented by formula I:

In formula I:

R ₁ and R is ₂ Each independently selected from the group consisting of C1-C30 hydrocarbyl containing substituents or C1-C30 hydrocarbyl containing no substituents, wherein R is repeated ₁ Or R is ₂ The same or different;

R ₅ -R ₈ each independently selected from hydrogen, halogen, hydroxy, C1-C20 hydrocarbyl containing substituents or C1-C20 hydrocarbyl containing no substituents, wherein R is repeated ₅ 、R ₆ 、R ₇ Or R is ₈ The same or different;

R ₅ -R ₈ optionally mutually looping;

R ₁₂ selected from substituent-containing C1-C20 hydrocarbyl or substituent-free C1-C20 hydrocarbyl, R being repeated ₁₂ The same or different;

y is selected from group VIA nonmetallic atoms, and repeated Y is the same or different;

m is a group VIII metal, and repeated M's are the same or different;

x is selected from halogen, C1-C10 alkyl containing substituent, C1-C10 alkyl containing no substituent, C1-C10 alkoxy containing substituent or C1-C10 alkoxy containing no substituent.

In the present invention, R is repeated ₁ Or R is ₂ The same or different means: repeated R ₁ Identical or different, repeated R ₁ The same or different; repeated R ₅ 、R ₆ 、R ₇ Or R is ₈ The same or different means: repeated R ₅ Identical or different, repeated R ₆ Identical or different, repeated R ₇ Identical or different, repeated R ₈ The same or different.

In the present invention, the substitution may be a substitution of carbon in the main chain or a substitution of hydrogen in carbon.

In a preferred embodiment, in formula I, R ₁ And R is ₂ Each independently selected from the group consisting of C1-C20 alkyl groups containing substituents, C1-C20 alkyl groups containing no substituents, C6-C20 aryl groups containing substituents, and C6-C20 aryl groups containing no substituents.

In a further preferred embodiment, in formula I, R ₁ And R is ₂ Each independently selected from the structures shown in formula II, wherein the asterisks indicate the linkage to N in formula I:

in formula II, R ¹ -R ⁵ Each independently selected from the group consisting of hydrogen, halogen, hydroxy, C1-C20 alkyl containing substituents, C1-C20 alkyl containing no substituents, C2-C20 alkenyl containing substituents, C2-C20 alkynyl containing no substituents, C3-C20 cycloalkyl containing no substituents, C1-C20 alkoxy containing no substituents, C2-C20 alkenyloxy containing substituents, C2-C20 alkenyloxy free of substituents, C2-C20 alkynyloxy free of substituents, C3-C20 cycloalkoxy free of substituents, C6-C20 aryl free of substituents, C7-C20 aralkyl free of substituents, C7-C20 alkylaryl free of substituents or C7-C20 alkylaryl free of substituents, wherein R is ¹ -R ⁵ Optionally mutually cyclic, and repeating R ¹ 、R ² 、R ³ 、R ⁴ Or R is ⁵ The same or different;

preferably, in formula II, R ¹ -R ⁵ Each independently selected from the group consisting of hydrogen, halogen, hydroxy, C1-C10 alkyl containing a substituent, C1-C10 alkyl containing no substituent, C2-C10 alkenyl containing a substituent, C2-C10 alkenyl containing no substituent, C2-C10 alkynyl containing a substituent, C2-C10 alkynyl containing no substituent, C3-C10 cycloalkyl containing a substituent, C3-C10 cycloalkyl containing no substituent, C1-C10 alkoxy containing a substituent, C1-C10 alkoxy containing no substituent, C2-C10 alkenyloxy containing a substituent, C2-C10 alkynyloxy containing a substituent, C3-C10 cycloalkoxy containing a substituent, C6-C15 aryl containing no substituent, C7-C7 aralkyl containing a substituent, C7-C7 alkyl containing no substituent, and R15 aryl containing an aryl or R15 alkyl containing no substituent ¹ -R ⁵ OptionalAre mutually cyclic and R is repeated ¹ 、R ² 、R ³ 、R ⁴ Or R is ⁵ The same or different;

more preferably, in formula II, R ¹ -R ⁵ Each independently selected from hydrogen, halogen, C1-C5 alkyl or C1-C5 substituted alkyl, wherein R ¹ -R ⁵ Optionally mutually cyclic, and repeating R ¹ 、R ² 、R ³ 、R ⁴ Or R is ⁵ The same or different.

In the present invention, R is repeated ¹ 、R ² 、R ³ 、R ⁴ Or R is ⁵ The same or different means: repeated R ¹ Identical or different, repeated R ² Identical or different, repeated R ³ Identical or different, repeated R ⁴ Identical or different, repeated R ⁵ The same or different.

In a preferred embodiment, in formula I:

m is selected from nickel or palladium, wherein repeated M's are the same or different; preferably, M is nickel;

y is selected from O or S, wherein repeated Y are the same or different; preferably, Y is O;

x is selected from halogen, C1-C10 alkyl containing substituent, C1-C10 alkyl without substituent, C1-C10 alkoxy containing substituent or C1-C10 alkoxy without substituent, wherein repeated M is the same or different;

preferably, X is selected from halogen, C1-C6 alkyl containing substituents, C1-C6 alkyl containing no substituents, C1-C6 alkoxy containing substituents or C1-C6 alkoxy containing no substituents, wherein the repeated M's are the same or different;

more preferably, X is selected from fluorine, chlorine or bromine, wherein the repeated M's are the same or different;

R ₁₂ selected from C1-C20 alkyl groups containing substituents or C1-C20 alkyl groups containing no substituents, preferably C1-C10 alkyl groups containing substituents or C1-C10 alkyl groups containing no substituents, more preferably C1-C6 alkyl groups containing substituents or C1-C6 alkyl groups containing no substituents, R being repeated ₁₂ The same or different.

In the present invention, the substituent is selected from the group consisting of halogen, hydroxy, C1-C6 alkyl free of substituents, halogen-substituted C1-C6 alkyl, C1-C6 alkoxy free of substituents and halogen-substituted C1-C6 alkoxy.

In a preferred embodiment, the single-site compound is selected from at least one of the compounds of formula III:

in formula III: r is R ¹ -R ¹¹ Each independently selected from the group consisting of hydrogen, halogen, hydroxy, C1-C20 alkyl containing substituents, C1-C20 alkyl containing no substituents, C2-C20 alkenyl containing substituents, C2-C20 alkynyl containing no substituents, C3-C20 cycloalkyl containing no substituents, C1-C20 alkoxy containing no substituents, C2-C20 alkenyloxy containing substituents, C2-C20 alkenyloxy free of substituents, C2-C20 alkynyloxy free of substituents, C3-C20 cycloalkoxy free of substituents, C6-C20 aryl free of substituents, C7-C20 aralkyl free of substituents, C7-C20 alkylaryl free of substituents or C7-C20 alkylaryl free of substituents, repeated R ¹ -R ¹¹ The same or different. M, X, Y, R in formula III ₁₂ Has the same definition as formula I.

In a further preferred embodiment, in formula III, R ¹ -R ¹¹ Each independently selected from the group consisting of hydrogen, halogen, hydroxy, C1-C10 alkyl containing substituents, C1-C10 alkyl containing no substituents, C2-C10 alkenyl containing substituents, C2-C10 alkynyl containing no substituents, C3-C10 cycloalkyl containing no substituents, C1-C10 alkoxy containing no substituents, C2-C10 alkenyloxy containing no substituents, C3-C10 cycloalkyl containing no substituentsC2-C10 alkynyloxy of a group, C2-C10 alkynyloxy of a group without substituents, C3-C10 cycloalkoxy of a group with substituents, C3-C10 cycloalkoxy of a group without substituents, C6-C15 aryl of a group with substituents, C6-C15 aryl of a group without substituents, C7-C15 aralkyl of a group with substituents, C7-C15 aralkyl of a group without substituents, C7-C15 alkylaryl of a group with substituents or C7-C15 alkylaryl of a group without substituents, R being repeated ¹ -R ¹¹ The same or different. R is R ₁₂ Selected from C1-C20 alkyl, repeated R ¹² The same or different; x is selected from halogen, and repeated X are the same or different; y is selected from O or S, and repeated Y is the same or different; m is selected from nickel or palladium, and repeated M is the same or different.

In a still further preferred embodiment, in formula III, X is selected from Cl or Br, the repeated X's are identical or different, said R ¹ ～R ⁵ Each independently selected from C1-C10 alkyl or halogen, R being repeated ¹ ～R ⁵ The same or different; the R is ⁶ ～R ¹¹ Each independently selected from hydrogen, C1-C5 alkyl or halogen, R being repeated ⁶ ～R ¹¹ The same or different; r is R ₁₂ Selected from C1-C5 hydrocarbyl, repeating R ¹² The same or different; y is selected from O or S, and repeated Y is the same or different; m is selected from nickel or palladium, and repeated M is the same or different.

Wherein R is repeated ¹ -R ¹¹ The same or different means: repeated R ¹ Identical or different, repeated R ² Identical or different, repeated R ³ Identical or different, repeated R ⁴ Identical or different, repeated R ⁵ Identical or different, repeated R ⁶ Identical or different, repeated R ⁷ Identical or different, repeated R ⁸ Identical or different, repeated R ⁹ Identical or different, repeated R ¹⁰ Identical or different, repeated R ¹¹ The same or different; repeated R ¹ ～R ⁵ The same or different means: repeated R ¹ Identical or different, repeating R ² Identical or different, repeating R ³ Identical or different, repeating R ⁴ Identical or different, repeating R ⁵ The same or different; repeated R ⁶ ～R ¹¹ Identical or differentThe same is referred to as: repeated R ⁶ Identical or different, repeating R ⁷ Identical or different, repeating R ⁸ Identical or different, repeating R ⁹ Identical or different, repeating R ¹⁰ Identical or different, repeating R ¹¹ The same or different.

In the present invention:

the substituent is selected from halogen, hydroxy, C1-C10 alkyl without substituent, C1-C10 alkyl substituted by halogen, C1-C10 alkoxy without substituent or C1-C10 alkoxy substituted by halogen;

preferably, the substituents are selected from halogen, hydroxy, unsubstituted C1-C6 alkyl, halogen-substituted C1-C6 alkyl, unsubstituted C1-C6 alkoxy and halogen-substituted C1-C6 alkoxy

More preferably, the C1-C6 alkyl is selected from methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, n-pentyl, isopentyl, n-hexyl, isohexyl or 3, 3-dimethylbutyl; and/or the C1-C6 alkoxy is selected from methoxy, ethoxy, n-propoxy, isopropoxy, n-butoxy, isobutoxy, n-pentoxy, isopentoxy, n-hexoxy, isohexoxy or 3, 3-dimethylbutoxy; and/or the halogen is selected from fluorine, chlorine, bromine or iodine.

In a preferred embodiment, the single site compound is selected from at least one of the compounds 1) to 24) below:

1) Single active center compounds of formula III wherein R ¹ ＝R ³ Methyl, R ² ＝R ⁴ -R ⁷ ＝R ¹⁰ ＝H，R ⁸ ＝R ⁹ ＝R ¹¹ Methyl, R ₁₂ =ethyl, m=ni, y=o, x=br;

2) Single active center compounds of formula III wherein R ¹ ＝R ³ =ethyl, R ² ＝R ⁴ -R ⁷ ＝R ¹⁰ ＝H，R ⁸ ＝R ⁹ ＝R ¹¹ Methyl, R ₁₂ =ethyl, m=ni, y=o, x=br;

3) Single active center compounds of formula III wherein R ¹ ＝R ³ =isopropyl, R ² ＝R ⁴ -R ⁷ ＝R ¹⁰ ＝H，R ⁸ ＝R ⁹ ＝R ¹¹ Methyl, R ₁₂ =ethyl, m=ni, y=o, x=br;

4) Single active center compounds of formula III wherein R ¹ -R ³ Methyl, R ⁴ -R ⁷ ＝R ¹⁰ ＝H，R ⁸ ＝R ⁹ ＝R ¹¹ Methyl, R ₁₂ =ethyl, m=ni, y=o, x=br;

5) Single active center compounds of formula III wherein R ¹ ＝R ³ Methyl, R ² ＝Br，R ⁴ -R ⁷ ＝R ¹⁰ ＝H，R ⁸ ＝R ⁹ ＝R ¹¹ Methyl, R ₁₂ =ethyl, m=ni, y=o, x=br;

6) Single active center compounds of formula III wherein R ¹ ＝R ³ ＝F，R ² ＝R ⁴ -R ⁷ ＝R ¹⁰ ＝H，R ⁸ ＝R ⁹ ＝R ¹¹ Methyl, R ₁₂ =ethyl, m=ni, y=o, x=br;

7) Single active center compounds of formula III wherein R ¹ ＝R ³ ＝Cl，R ² ＝R ⁴ -R ⁷ ＝R ¹⁰ ＝H，R ⁸ ＝R ⁹ ＝R ¹¹ Methyl, R ₁₂ =ethyl, m=ni, y=o, x=br;

8) Single active center compounds of formula III wherein R ¹ ＝R ³ ＝Br，R ² ＝R ⁴ -R ⁷ ＝R ¹⁰ ＝H，R ⁸ ＝R ⁹ ＝R ¹¹ Methyl, R ₁₂ =ethyl, m=ni, y=o, x=br;

9) Single active center compounds of formula III wherein R ¹ ＝R ³ Methyl, R ² ＝R ⁴ -R ⁷ ＝R ¹⁰ ＝H，R ⁸ ＝R ⁹ ＝R ¹¹ Methyl, R ₁₂ Isobutyl, m=ni, y=o, x=br;

10 Single-site compounds of formula III, wherein R ¹ ＝R ³ =ethyl, R ² ＝R ⁴ -R ⁷ ＝R ¹⁰ ＝H，R ⁸ ＝R ⁹ ＝R ¹¹ Methyl, R ₁₂ Isobutyl, m=ni, y=o, x=br;

11 Single-site compounds of formula III, wherein R ¹ ＝R ³ =isopropyl, R ² ＝R ⁴ -R ⁷ ＝R ¹⁰ ＝H，R ⁸ ＝R ⁹ ＝R ¹¹ Methyl, R ₁₂ Isobutyl, m=ni, y=o, x=br;

12 Single-site compounds of formula III, wherein R ¹ -R ³ Methyl, R ⁴ -R ⁷ ＝R ¹⁰ ＝H，R ⁸ ＝R ⁹ ＝R ¹¹ Methyl, R ₁₂ Isobutyl, m=ni, y=o, x=br;

13 Single-site compounds of formula III, wherein R ¹ ＝R ³ Methyl, R ² ＝Br，R ⁴ -R ⁷ ＝R ¹⁰ ＝H，R ⁸ ＝R ⁹ ＝R ¹¹ Methyl, R ₁₂ Isobutyl, m=ni, y=o, x=br;

14 Single-site compounds of formula III, wherein R ¹ ＝R ³ ＝F，R ² ＝R ⁴ -R ⁷ ＝R ¹⁰ ＝H，R ⁸ ＝R ⁹ ＝R ¹¹ Methyl, R ₁₂ Isobutyl, m=ni, y=o, x=br;

15 Single-site compounds of formula III, wherein R ¹ ＝R ³ ＝Cl，R ² ＝R ⁴ -R ⁷ ＝R ¹⁰ ＝H，R ⁸ ＝R ⁹ ＝R ¹¹ Methyl, R ₁₂ Isobutyl, m=ni, y=o, x=br;

16 Single-site compounds of formula III, wherein R ¹ ＝R ³ ＝Br，R ² ＝R ⁴ -R ⁷ ＝R ¹⁰ ＝H，R ⁸ ＝R ⁹ ＝R ¹¹ Methyl group =methyl group，R ₁₂ Isobutyl, m=ni, y=o, x=br;

17 Single-site compounds of formula III, wherein R ¹ ＝R ³ Methyl, R ² ＝R ⁴ -R ⁷ ＝R ¹⁰ ＝H，R ⁸ ＝R ⁹ Methyl, R ¹¹ Bromomethyl group, R ₁₂ =ethyl, m=ni, y=o, x=br;

18 Single-site compounds of formula III, wherein R ¹ ＝R ³ =ethyl, R ² ＝R ⁴ -R ⁷ ＝R ¹⁰ ＝H，R ⁸ ＝R ⁹ Methyl, R ¹¹ Bromomethyl group, R ₁₂ =ethyl, m=ni, y=o, x=br;

19 Single-site compounds of formula III, wherein R ¹ ＝R ³ =isopropyl, R ² ＝R ⁴ -R ⁷ ＝R ¹⁰ ＝H，R ⁸ ＝R ⁹ Methyl, R ¹¹ Bromomethyl group, R ₁₂ =ethyl, m=ni, y=o, x=br;

20 Single-site compounds of formula III, wherein R ¹ -R ³ Methyl, R ⁴ -R ⁷ ＝R ¹⁰ ＝H，R ⁸ ＝R ⁹ Methyl, R ¹¹ Bromomethyl group, R ₁₂ =ethyl, m=ni, y=o, x=br;

21 Single-site compounds of formula III, wherein R ¹ ＝R ³ Methyl, R ² ＝Br，R ⁴ -R ⁷ ＝R ¹⁰ ＝H，R ⁸ ＝R ⁹ Methyl, R ¹¹ Bromomethyl group, R ₁₂ =ethyl, m=ni, y=o, x=br;

22 Single-site compounds of formula III, wherein R ¹ ＝R ³ ＝F，R ² ＝R ⁴ -R ⁷ ＝R ¹⁰ ＝H，R ⁸ ＝R ⁹ Methyl, R ¹¹ Bromomethyl group, R ₁₂ =ethyl, m=ni, y=o, x=br;

23 Single-site compounds of formula III, whereinR ¹ ＝R ³ ＝Cl，R ² ＝R ⁴ -R ⁷ ＝R ¹⁰ ＝H，R ⁸ ＝R ⁹ Methyl, R ¹¹ Bromomethyl group, R ₁₂ =ethyl, m=ni, y=o, x=br;

24 Single-site compounds of formula III, wherein R ¹ ＝R ³ ＝Br，R ² ＝R ⁴ -R ⁷ ＝R ¹⁰ ＝H，R ⁸ ＝R ⁹ Methyl, R ¹¹ Bromomethyl group, R ₁₂ =ethyl, m=ni, y=o, x=br.

In the present invention, the single site compound is preferably a diimine metal complex as described in the prior application CN 201911048975.0.

In a preferred embodiment, the inorganic support is an oxide of silicon and/or aluminum, preferably silica and/or aluminum dioxide, more preferably silica (e.g., silica gel).

In the present invention, the single-site catalyst having high activity can be produced by spray-forming by using an inorganic oxide (preferably an ultrafine inorganic oxide) as a carrier, treating with a carrier modifier and an organoaluminum compound, and adding a single-site compound of an appropriate structure.

In a further preferred embodiment, the particle size of the inorganic support is from 0.01 to 10. Mu.m, preferably from 0.02 to 5. Mu.m, more preferably from 0.05 to 1. Mu.m.

Among these, the catalyst of the present invention may employ an inorganic carrier having a relatively small particle size, particularly a silica carrier having a relatively small particle size (e.g., silica gel having a small particle size).

In a preferred embodiment, the support modifier is a halosilane.

In a further preferred embodiment, the halosilane has the formula SiR ^a R ^b X' _x Wherein R is ^a And R is ^b Selected from independently selected hydrogen, C ₁ -C ₁₀ X' represents halogen, x.gtoreq.2; preferably, R ^a And R is ^b Selected from C ₁ -C ₅ X' is selected from chlorine and/or bromine, X is not less than 2.

Thus, the carrier modifier contains at least 2 halogens, and specifically may contain 2 to 4 halogens. In the invention, the carrier is treated by adopting the carrier modifier, so that the hydroxyl or moisture on the surface of the carrier can be removed, and the catalyst deactivation caused by the hydroxyl or moisture on the surface of the carrier is avoided. Meanwhile, the carrier modifier can be adopted to reconfigure the carrier with smaller particle size further to form effective accumulation. In short, the purpose of adding the carrier modifier is to make the nano silica gel particles have a certain interaction force, and can keep a certain space accumulation form after drying and forming, but not be easily broken and dispersed.

In a still further preferred embodiment, the carrier modifier is selected from at least one of dichlorodimethylsilicon, trichloromethylicon, trichlorophenylicon, dichloromethylpropylicon, and trichlorohexylicon.

In a preferred embodiment, the organoaluminum compound is selected from the group consisting of compounds of the general formula A1R ^c _n X” _3-n At least one of the compounds of (1), wherein R ^c Selected from hydrogen or C ₁ -C ₂₀ X' is halogen, n is more than 0 and less than or equal to 3.

In a further preferred embodiment, the organoaluminum compound is selected from the group consisting of compounds of the general formula A1R ^c _n X” _3-n At least one of the compounds of (1), wherein R ^c Selected from hydrogen or C ₁ -C ₁₀ X' is fluorine, chlorine or bromine, n is more than 0 and less than or equal to 3.

In a preferred embodiment, the inorganic carrier is present in an amount of 30 to 70wt%, the carrier modifier is present in an amount of 10 to 40wt%, the organoaluminum compound is present in an amount of 0.5 to 15wt%, and the single-site compound is present in an amount of 0.05 to 4wt%, based on 100wt% of the total weight of all components, wherein the single-site compound is present in an amount based on the amount of the metal element M therein.

In a further preferred embodiment, the inorganic carrier is present in an amount of 45 to 60 wt.%, the carrier modifier is present in an amount of 15 to 30 wt.%, the organoaluminum compound is present in an amount of 1 to 10 wt.%, and the single-site compound is present in an amount of 0.5 to 2 wt.%, based on 100 wt.% of the total weight of all raw materials, wherein the single-site compound is present in an amount based on the content of the metal element M therein.

Wherein 100wt% based on the total weight of the mixture means 100wt% based on the total weight of the inorganic carrier, the carrier modifier, the organoaluminum compound and the single-site compound, for example, the single-site compound is contained in an amount of 0.05wt%, 0.1wt%, 0.2wt%, 0.3wt%, 0.5wt%, 1wt%, 1.5wt%, 2wt%, 2.5wt%, 3wt% or 4wt%; and/or the organoaluminum compound is present in an amount of 0.5wt%, 1wt%, 2wt%, 3wt%, 4wt%, 5wt%, 6wt%, 7wt%, 8wt%, 9wt%, 10wt%, 11wt%, 12wt%, 13wt%, 14wt% or 15wt%; and/or, the content of the inorganic carrier is 30wt%, 40wt%, 45wt%, 50wt%, 55wt%, 60wt%, 65wt%, 70wt%, 80wt%; and/or the content of the carrier modifier is 10wt%, 15wt%, 20wt%, 25wt%, 30wt%, 35wt% or 40wt%.

In the present invention, silica gel is used as a carrier, which is the main component of the catalyst, and the single-site compound is supported on the carrier to obtain the required stereo form. The organic aluminum compound and the carrier modifier are used for treating the surface and partially exciting the active center of the catalyst, so that the dosage is not too large.

The second object of the present invention is to provide a method for preparing the single-site catalyst according to one of the objects of the present invention, comprising: mixing the inorganic carrier, the carrier modifier, the organic aluminum compound and the single-site compound with a solvent, and then performing spray drying to obtain the single-site catalyst.

The inorganic carrier is silicon and/or aluminum oxide, wherein the silicon and/or aluminum oxide is an inert carrier, the inert carrier is used in spray drying to help control the shape and composition of the catalyst particles, the spray forming is facilitated, and the formed catalyst particles are good in shape and high in strength.

In a preferred embodiment, the solvent is an inert solvent, preferably at least one selected from hexane, benzene, toluene, chloroform, dichloromethane.

In a preferred embodiment, the mixing is carried out at 20℃to 90℃and preferably at normal temperature to 70℃such as, for example, normal temperature, 30℃40℃50℃60℃or 70 ℃.

In a further preferred embodiment, the mixing is performed at a pressure of 0.5MPa or less, preferably at a pressure of 0.2MPa or less, for example, at normal pressure.

In a still further preferred embodiment, the time of mixing is 1 hour or more, preferably 2 hours or more.

In a preferred embodiment, the mixed material is subjected to a temperature reduction treatment prior to spray drying.

In a further preferred embodiment, the mixed material is cooled to 30-55 ℃, e.g. 30 ℃, 40 ℃, 50 ℃ or 55 ℃ before spray drying.

In a preferred embodiment, the spray drying conditions are: the inlet temperature is 60-240 ℃; the outlet temperature is 60-130 ℃.

In a further preferred embodiment, the spray drying conditions are: the inlet temperature is 70-160 ℃; the outlet temperature is 70-120 ℃.

For example, the spray drying inlet temperature is 60 ℃, 70 ℃, 80 ℃, 90 ℃, 100 ℃, 110 ℃, 120 ℃, or 130 ℃; the spray-dried product has an outlet temperature of 70 ℃, 80 ℃, 90 ℃, 100 ℃, 110 ℃ or 120 ℃.

In a preferred embodiment, the method comprises the steps of:

(a) Firstly, mixing the inorganic carrier, the carrier modifier and the solvent to obtain a mixed solution;

(b) Adding the organic aluminum compound and the single-active-center compound into the mixed solution to obtain slurry;

(c) And (3) carrying out spray drying on the slurry to obtain the single-site catalyst.

In a further preferred embodiment, step (a) is carried out at 20-50 ℃; and/or step (b) is carried out at 50-70 ℃.

In the present invention, the preparation of the single site compound is described in the prior application CN201911048975.0 for the preparation of the diimine metal complexes.

In a preferred embodiment, the method of preparing the single site compound comprises: step (d), a compound of formula IV and MX _n And R is ₁₂ YH reacts to generate the compound shown in the formula I.

Wherein R in formula IV ₁ 、R ₂ 、R ₅ -R ₈ Having the same definition as formula I; MX (MX) _n Wherein M and X have the same definition as formula I, and n is the number of X satisfying the valence of M, such as 1,2 or 3; r is R ₁₂ Y and R in YH ₁₂ Has the same definition as formula I.

In a further preferred embodiment, the compound of formula IV has the structure of formula IV:

wherein R in formula IV ₁ 、R ₂ Having the same definition as formula I, R ⁶ -R ¹¹ Has the same definition as formula III.

In a preferred embodiment, the reaction of step (c) is carried out in an organic solvent.

In a further preferred embodiment, the organic solvent is a haloalkane, preferably the organic solvent is selected from one or more of dichloromethane, chloroform and 1, 2-dichloroethane.

In a preferred embodiment, the reaction of step (c) is carried out at a temperature of 15-40 ℃.

In a preferred embodimentThe MX _n Including nickel halides, such as nickel bromide and nickel chloride, and 1, 2-dimethoxyethane nickel halides, such as 1, 2-dimethoxyethane nickel bromide and 1, 2-dimethoxyethane nickel chloride.

In a preferred embodiment, the preparation of the compound of formula IV comprises: step e), a compound of formula V and R ₁ NH ₂ And R is ₂ NH ₂ Reacting to generate the compound shown in the formula IV,

wherein R is ₁ 、R ₂ 、R ₅ -R ₈ Has the same definition as formula I.

In a preferred embodiment, the reaction of step e) is in the presence of an aluminum alkyl and an aprotic solvent, preferably one or more of toluene, benzene, xylene; the alkyl aluminum is a C1-C6 alkyl aluminum compound, preferably at least one of trimethyl aluminum, triethyl aluminum, tripropyl aluminum, such as trimethyl aluminum.

In a preferred embodiment, the reaction of step e) comprises reacting R ₁ NH ₂ And R is ₂ NH ₂ And (3) carrying out a first reflux reaction with aluminum alkyl, and carrying out a second reflux reaction of the first reflux reaction product and the compound shown in the formula V.

In a preferred embodiment, the compound of formula V has the structure of formula VI:

In formula VI, R ⁶ -R ¹¹ Is defined as in formula III.

In a preferred embodiment, the inorganic carrier is present in an amount of 1 to 20wt%, the carrier modifier is present in an amount of 0.5 to 6wt%, the organoaluminum compound is present in an amount of 0.01 to 5wt%, and the single-site compound is present in an amount of 0.01 to 4wt%, based on 100wt% of the total weight of all the raw materials, wherein the single-site compound is present in an amount based on the amount of the metal element M contained therein.

In a further preferred embodiment, the inorganic carrier is present in an amount of 2 to 10 wt.%, the carrier modifier is present in an amount of 1.5 to 4 wt.%, the organoaluminum compound is present in an amount of 0.05 to 2 wt.%, and the single-site compound is present in an amount of 0.05 to 3 wt.%, based on 100 wt.% of the total weight of all raw materials, wherein the single-site compound is present in an amount based on the amount of the metal element M present therein.

Wherein, the total amount of the raw materials is 100 percent, namely the total amount of the single active center compound, the organic aluminum compound, the inorganic carrier, the carrier modifier and the solvent is 100 percent by weight. For example, the single site compound is used in an amount of 0.01wt%, 0.05wt%, 0.1wt%, 0.2wt%, 0.3wt%, 0.5wt%, 1wt%, 1.5wt%, 2wt%, 2.5wt%, 3wt% or 4wt%; and/or the organoaluminum compound is present in an amount of 0.01wt%, 0.02wt%, 0.05wt%, 0.08wt%, 0.1wt%, 0.2wt%, 0.5wt%, 0.8wt%, 1wt%, 1.5wt%, 2wt%, 3wt%, 4wt%, or 5wt%; and/or, the inorganic carrier is added in an amount of 1wt%, 2wt%, 3wt%, 4wt%, 5wt%, 6wt%, 7wt%, 8wt%, 9wt%, 10wt%, 15wt% or 20wt%; and/or, the passivating agent is added in an amount of 0.5wt%, 0.8wt%, 1wt%, 1.5wt%, 2wt%, 2.5wt%, 3wt%, 3.5wt%, 4wt%, 5wt% or 6wt%.

The third object of the present invention is to provide a single-site catalyst obtained by the second preparation method of the present invention.

It is a fourth object of the present invention to provide a composite catalyst for olefin polymerization comprising the single site catalyst and an organoaluminum catalyst as described in one or three of the objects of the present invention.

In a kind ofIn a preferred embodiment, the organoaluminum catalyst is selected from the group consisting of those having the general formula A1R ^d _m X”' _3-m At least one of the compounds of (1), wherein R ^d Selected from hydrogen or C ₁ -C ₂₀ X' "is halogen, m is more than 0 and less than or equal to 3.

In a further preferred embodiment, the organoaluminum catalyst is selected from the group consisting of compounds of the general formula A1R ^d _m X” _3-n At least one of the compounds of (1), wherein R ^d Selected from hydrogen or C ₁ -C ₁₀ X' "is fluorine, chlorine or bromine, m is more than 0 and less than or equal to 3.

In a still further preferred embodiment, the organoaluminum catalyst is preferably, but not limited to, at least one selected from triethylaluminum, triisobutylaluminum, tri-n-hexylaluminum, tri-n-octylaluminum, diethylaluminum monochloride.

In a preferred embodiment, the molar ratio of aluminum in the organoaluminum catalyst to metal M in the single-site catalyst is from (5 to 500): 1, preferably from (10 to 200): 1.

For example, the molar ratio of aluminum in the organoaluminum catalyst to metal M in the single-site catalyst is 10:1, 50:1, 100:1, 150:1, 200:1, 250:1, 300:1, 350:1, 400:1, 450:1, or 500:1.

In the present invention, the single site catalyst is treated with an activator component organoaluminum catalyst to render it suitable for use in the production of ethylene polymers.

In general, the composite catalyst may be prepared first: mixing and/or reacting the obtained olefin polymerization catalyst with an organic aluminum catalyst in a hydrocarbon solvent to obtain the composite catalyst; the resulting olefin polymerization catalyst may also be mixed and/or reacted with an organoaluminum catalyst during polymerization to initiate the olefin polymerization reaction.

Preferably, the hydrocarbon solvent is a hydrocarbon solvent which can dissolve reaction components and does not affect the reaction, and may be isopentane, hexane, heptane, toluene, xylene, naphtha, mineral oil, and the like, for example.

It is a fifth object of the present invention to provide the use of the catalyst according to one of the objects of the present invention or the composite catalyst according to the fourth object of the present invention in olefin polymerization, preferably the polymerization is gas phase polymerization or slurry polymerization, more preferably the polymerization is ethylene homo-polymerization.

The sixth object of the present invention is to provide a process for polymerizing olefins comprising: in the presence of the single-site catalyst of one of the purposes of the present invention or the composite catalyst of the fourth of the purposes of the present invention, olefin monomers are polymerized to obtain polyolefin.

In a preferred embodiment, the olefin has the formula CH ₂ ＝CHR ^e Wherein R is ^e Selected from hydrogen or C1-C6 alkyl.

In a further preferred embodiment, the olefin is selected from at least one of ethylene, propylene, butene, pentene, hexene, octene and 4-methylpentene-1.

According to the present invention, the olefin polymerization catalyst or the composite catalyst of the present invention is suitable for homo-polymerization and copolymerization of olefins; is especially suitable for homo-polymerization of ethylene or copolymerization of ethylene and other alpha-olefins; in particular, low density polyethylene can be produced by mere polymerization of ethylene without the addition of alpha-olefins.

The olefin polymerization process of the present invention can be carried out according to a known polymerization process, either in a liquid phase or a gas phase, or in a combination of liquid and gas phase polymerization stages. The conventional techniques such as slurry process, gas-phase fluidized bed, solution process, etc. are adopted, and are more suitable for gas-phase polymerization.

According to some embodiments of the invention, the polymerization temperature is 65 ℃ to 90 ℃.

According to some embodiments of the invention, the polymerization temperature is from 70 ℃ to 80 ℃.

For example, the polymerization temperature is 65 ℃, 70 ℃, 75 ℃, 80 ℃, 85 ℃, or 90 ℃.

The endpoints of the ranges and any values disclosed in the present invention are not limited to the precise range or value, and the range or value should be understood to include values close to the range or value. For numerical ranges, one or more new numerical ranges may be found between the endpoints of each range, between the endpoint of each range and the individual point value, and between the individual point value, in combination with each other, and are to be considered as specifically disclosed herein. In the following, the individual technical solutions can in principle be combined with one another to give new technical solutions, which should also be regarded as specifically disclosed herein.

Compared with the prior art, the invention has the following beneficial effects:

(1) The single-site catalyst or the composite catalyst is particularly suitable for ethylene homopolymerization reaction, and can be used for preparing low-density polyethylene products;

(2) The single-site catalyst or the composite catalyst has high activity, extremely specific polymerization performance, can prepare a low-density polyethylene product without a comonomer, and can flexibly adjust the product brand through adjustment of reaction temperature and pressure according to production requirements; the method is suitable for various polymerization processes, particularly in a low-boiling-point slurry process, the obtained powder is not sticky, and the powder has good fluidity;

(3) The single-site catalyst or the composite catalyst has high polymerization activity, high powder melt index and excellent comprehensive performance at a lower polymerization temperature.

Detailed Description

The present invention is described in detail below with reference to specific embodiments, and it should be noted that the following embodiments are only for further description of the present invention and should not be construed as limiting the scope of the present invention, and some insubstantial modifications and adjustments of the present invention by those skilled in the art from the present disclosure are still within the scope of the present invention.

In addition, the specific features described in the following embodiments may be combined in any suitable manner without contradiction. The various possible combinations of the invention are not described in detail in order to avoid unnecessary repetition.

In addition, any combination of the various embodiments of the present invention can be made, so long as the concept of the present invention is not deviated, and the technical solution formed thereby is a part of the original disclosure of the present specification, and also falls within the protection scope of the present invention.

The raw materials used in examples and comparative examples, if not particularly limited, are all as disclosed in the prior art, and are, for example, available directly or prepared according to the preparation methods disclosed in the prior art.

The testing method comprises the following steps:

1. activity: expressed as weight of resin obtained per gram of catalyst.

2. Polymer Melt Index (MI): the measurement was performed using a CEAST company 6932 melt index meter.

3. Polymer apparent density (BD): the measurements were made with reference to ASTM D1895-69.

4. Nickel and silicon content: the measurement and analysis were performed by using an elemental analyzer of 7500cx ICP-MS, aglient corporation, USA.

5. Polymer density: the measurement was performed by a density gradient tube method with reference to national standard 1033.2.

Example 1

(1) Preparation of the catalyst

Under the protection of nitrogen, 2, 6-diethylaniline (200 ml,1.2 mol) is dissolved in 2L toluene, 1.2L (1.0M, 1.2 mol) of trimethylaluminum is dripped at normal temperature, the reaction is refluxed for 2 hours, the system is cooled to the room temperature, camphorquinone (83.1 g,0.5 mol) is added, and the system is refluxed for 6 hours. Neutralizing the reaction product with sodium hydroxide aqueous solution, extracting with dichloromethane, drying, and column chromatography to obtain yellow ligand L ₁ The yield was 69.2%. ¹ H-NMR(CDCl ₃ ):δ6.94-6.92(m,6H,C _Ar -CH ₃ ),2.56-2.51(m,4H,C _Ar -CH ₃ ),2.36-2.31(m,4H,C _Ar -CH ₃ ),1.82-1.78(m,4H,CH ₂ ),1.54(m,1H),1.24-1.18(m,12H),1.09(s,3H,CH ₃ ),0.94(m,6H,CH ₃ )。

Will contain 27.7g (90 mmol) (DME) NiBr ₂ Is slowly added dropwise to an ethanol solution containing 25.8g (60 mmol) of ligand L ₁ Is in methylene chloride solution. The color of the solution immediately changed to dark red and a large amount of precipitate was formed. Stirring at room temperature for 6h, adding anhydrous diethyl ether for precipitation. Filtering to obtain a filter cake, washing the filter cake with anhydrous diethyl ether, and vacuum drying to obtain a single active center compound Ni ₁ . Yield: 78.2%. Elemental analysis (C) ₆₄ H ₉₀ Br ₆ N ₄ Ni ₃ O ₂ ): c,47.96; h,5.66; n,3.50; experimental values (%): c,47.48; h,6.00; n,3.26.

Dispersing 20g of silica gel (particle size of 0.05-0.10 microns) in 300mL of chloroform, uniformly stirring, adding 5mL of dichlorodimethylsilicon, heating to 45 ℃, treating for 2 hours, and then adding a single active center compound Ni ₁ 5.35g and 10mL of a solution of diethylaluminum chloride in hexane (10%) were reacted at 55℃for 2 hours. Cooling to 45 deg.C, and spray drying. Spray drying conditions: the inlet temperature was 130℃and the outlet temperature was 70℃to obtain 31g of the catalyst. Wherein the Ni content is 1.7%.

(2) Slurry polymerization of ethylene

1 liter of hexane was added to a 2 liter polymerization reactor purged with nitrogen, 10ml of Methylaluminoxane (MAO) (1.53 mol/L in toluene) and 25mg of the catalyst were added simultaneously, the temperature was raised to 70℃and ethylene was added at 1.1MPa, and after 1 hour of reaction, the temperature was lowered and discharged. The polymerization results are shown in Table 1.

(3) Gas phase polymerization of ethylene

Taking 100 g of the catalyst obtained in the step (1), adding the catalyst into a catalyst feeding preparation kettle, preparing a suspension with 5L of hexane, and feeding the suspension into a peristaltic pumpAnd (3) adding triethylaluminum into the gas-phase fluidized bed to adjust the aluminum-nickel molar ratio to 50, adjusting the reaction temperature to 70 ℃, adjusting the hydrogen-ethylene partial pressure ratio to 0.05, adding no comonomer, and carrying out ethylene homopolymerization for 72 hours. The polymerization results are shown in Table 2.

Example 2

(1) Preparation of the catalyst

The catalyst was prepared as in example 1. Only change chloroform into dichloromethane, change the treatment condition into 40 ℃, feed spraying when the temperature is reduced to 30 ℃, change the spraying condition into: the inlet temperature is 90 ℃, the outlet temperature is 55 ℃, and the nickel content in the obtained catalyst is 1.7wt%.

(2) The ethylene slurry polymerization process was the same as in example 1, and the polymerization results are shown in Table 1.

(3) The ethylene gas phase polymerization process was the same as in example 1 and the polymerization results are shown in Table 2.

Example 3

(1) Preparation of the catalyst

Single active center compound Ni ₁ Is prepared as in example 1;

130mL of chloroform, 6 g of silica gel (Cabot Corporation TS-610, particle size of 0.05-0.5 μm) and 3mL of dimethyl silicon dichloride are sequentially added into a 250mL four-necked flask which is blown off by nitrogen, stirred at room temperature for one hour, and then 2 g of Shan Huoxing center compound Ni is added ₁ 10mL of chlorodiethyl aluminum hexane solution (10%) was heated to 60℃with stirring, and reacted at this temperature for 3 hours at constant temperature. Then cooling to 35 ℃.

Spray-drying the slurry obtained by using a spray dryer under spray conditions: the inlet temperature is 140 ℃, the outlet temperature is 102 ℃, and the catalyst is obtained, wherein the nickel content is 1.13wt%.

(2) Ethylene slurry polymerization was evaluated in the same manner as in example 1 and the polymerization results are shown in Table 1.

Example 4

(1) Preparation of the catalyst:

single active center compound Ni ₁ Is prepared as in example 1;

170L of dichloromethane, 10 kg of silica gel (Cabot Corporation TS-610, particle size of 0.05-0.5 micron) and 3L of dichlorodimethylsilicon are added into a 300L reaction kettle, stirred for one hour at room temperature, and then 2.1 kg of single-active-center compound Ni is added ₁ 2 liters of Methylaluminoxane (MAO) (1.53 mol/L in toluene), and the temperature was raised to 40℃with stirring, and the reaction was carried out at this temperature for 3 hours at constant temperature. Then cooling to 30deg.C, spray drying the obtained slurry with centrifugal spray dryer under spray conditions: the inlet temperature was 85℃and the outlet temperature was 64℃to obtain 20 kg of a solid catalyst, in which Ni content was 1.57Wt%.

(2) Ethylene slurry polymerization process

1 liter of hexane and 2 milliliters of triethylaluminum (1M hexane solution) and 25mg of supported catalyst are added into a 2 liter polymerization kettle blown off by nitrogen, the temperature is raised to 70 ℃, ethylene is added to 1.1Mpa, and after 1 hour of reaction, the temperature is reduced and the material is discharged. The polymerization results are shown in Table 1.

Example 5

(1) Preparation of the catalyst

Complex Ni ₂ (R in the formula III) ¹ 、R ³ Is isopropyl, R ² 、R ⁴ -R ⁷ 、R ¹⁰ Is hydrogen, R ⁸ 、R ⁹ And R is ¹¹ Is methyl, R ₁₂ Isobutyl, M is nickel, Y is O, X is Br):

under the protection of nitrogen, 2, 6-diisopropylaniline (2.4 ml,12 mmol) is dissolved in 20ml toluene, trimethylaluminum (12 ml, 1.0M,12 mmol) is dripped into the mixture at normal temperature, the reaction is refluxed for 2 hours, the system is cooled to room temperature, camphorquinone (0.831 g,5 mmol) is added, and the system is refluxed for 6 hours. Neutralizing the reaction product with sodium hydroxide aqueous solution, extracting with dichloromethane, drying, and column chromatography to obtain yellow ligand L ₂ The yield was 41.3%. ¹ H NMR(300MHz,CDCl3),δ(ppm):7.06-6.81(m,6H,Ar-H),2.88(m,4H,CH(CH ₃ ) ₂ ),2.36(m,1H),1.86(m,4H,CH ₂ ),1.24(d,24H,CH(CH ₃ ) ₂ ),0.96(s,6H,CH ₃ at camphyl),0.77(s,3H,CH ₃ )。

Will contain 0.277g (0.9 mmol) (DME) NiBr ₂ 2-methyl-1-propanol (10 ml) solution containing 0.291g (0.6 mmol) of ligand L was slowly added dropwise ₂ In methylene chloride (10 ml). The color of the solution immediately changed to dark red and a large amount of precipitate was formed. Stirring at room temperature for 6h, adding anhydrous diethyl ether for precipitation. Filtering to obtain a filter cake, washing the filter cake with anhydrous diethyl ether, and vacuum drying to obtain brownish red powdery solid Ni ₂ . The yield was 74.0%. Elemental analysis(C ₇₆ H ₁₁₄ Br ₆ N ₄ Ni ₃ O ₂ ): c,51.54; h,6.49; n,3.16; experimental values (%): c,51.28; h,6.82; n,3.19.

130mL of methylene chloride, 17 g of silica gel (Cabot Corporation TS-610, particle size of 0.05-0.5 μm) and 5mL of trichloromethyl silicon are added into a 250mL four-necked flask which is blown off by nitrogen, and stirred at room temperature for two hours, and then 3.9 g of nickel complex Ni is added ₂ 0.313 mL of diethyl aluminum chloride and 2mL of diethyl aluminum chloride are heated to 40 ℃ under stirring, and the reaction is carried out for 2 hours at constant temperature. Spray-drying the slurry obtained by using a spray dryer under spray conditions: the inlet temperature is 80 ℃, the outlet temperature is 60 ℃, and the solid catalyst component is obtained, wherein the nickel content is 1.21wt%.

Example 6

(1) Preparation of the catalyst (R in formula (III)) ¹ 、R ³ Is isopropyl, R ² 、R ⁴ -R ⁷ 、R ¹⁰ Is hydrogen, R ⁸ 、R ⁹ And R is ¹¹ Is methyl, R ₁₂ Ethyl, M is nickel, Y is O, X is Br

Will contain 0.277g (0.9 mmol) (DME) NiBr ₂ Slowly drop wise to a solution of (10 ml) of ethanol containing 0.291g (0.6 mmol) of ligand L ₂ In methylene chloride (10 ml). The color of the solution immediately changed to dark red and a large amount of precipitate was formed. Stirring at room temperature for 6h, addingAnhydrous diethyl ether was precipitated. Filtering to obtain a filter cake, washing the filter cake with anhydrous diethyl ether, and vacuum drying to obtain brownish red powdery solid Ni ₃ . The yield was 74.0%. Elemental analysis (C) ₇₂ H ₁₀₆ Br ₆ N ₄ Ni ₃ O ₂ ): c,50.42; h,6.23; n,3.27; experimental values (%): c,50.28; h,6.42; n,3.18.

130mL of methylene chloride, 13 g of silica gel (Cabot Corporation TS-610, particle size of 0.05-0.5 μm) and 3mL of dimethyl silicon dichloride are sequentially added into a 250mL four-necked flask which is blown off by nitrogen, and the mixture is stirred at room temperature for two hours, and then 2mL of triisobutylaluminum and 5.3 g of nickel complex Ni are added ₃ Heating to 40 ℃ under stirring, and reacting for 2 hours at constant temperature. Spray-drying the slurry obtained by using a spray dryer under spray conditions: the inlet temperature is 85 ℃, the outlet temperature is 65 ℃, and the solid catalyst component is obtained, wherein the Ni content is 1.73wt%.

Example 7

(1) Preparation of the catalyst

Complex Ni ₄ (R in the formula III) ¹ 、R ³ Is fluorine, R ² 、R ⁴ -R ⁷ 、R ¹⁰ Is hydrogen, R ⁸ 、R ⁹ And R is ¹¹ Is methyl, R ₁₂ Ethyl, M is nickel, Y is O, X is Br).

Under the protection of nitrogen, 2, 6-difluoroaniline (1.3 ml,12 mmol) is dissolved in 20ml toluene, trimethylaluminum (12 ml, 1.0M,12 mmol) is dripped at normal temperature, the reaction is refluxed for 2 hours, the system is cooled to room temperature, camphorquinone (0.831 g,5 mmol) is added, and the system is refluxed for 6 hours. Neutralizing the reaction product with sodium hydroxide aqueous solution, extracting with dichloromethane, drying, and column chromatography to obtain yellow ligand L ₃ The yield is 50.3%. ¹ HNMR(CDCl ₃ ):δ[an isomer ratio of 1.2:1]:major isomer:6.83-6.74(m,6H,C _Ar -CH ₃ ),1.93-1.90(m,4H,CH ₂ ),1.55(m,1Hl),1.26(s,3H,CH ₃ ),1.06(s,6H,CH ₃ ),Minor isomer:6.91-6.84(m,6H,C _Ar -CH ₃ ),1.96-1.94(m,4H,CH ₂ ),1.55(m,1H,),1.26(s,3H,CH ₃ ),1.02(s,6H,CH ₃ )。

Will contain 0.277g (0.9 mmol) (DME) NiBr ₂ Is slowly added dropwise to a solution of (10 ml) of ethanol containing 0.233g (0.6 mmol) of ligand L ₃ In methylene chloride (10 ml). The color of the solution immediately changed to dark red and a large amount of precipitate was formed. Stirring at room temperature for 6h, adding anhydrous diethyl ether for precipitation. Filtering to obtain a filter cake, washing the filter cake with anhydrous diethyl ether, and vacuum drying to obtain brownish red powdery solid Ni ₄ . The yield was 74.3%. Elemental analysis (C) ₄₈ H ₅₀ Br ₆ F ₈ N ₄ Ni ₃ O ₂ ): c,37.87; h,3.31; n,3.68; experimental values (%): c,37.78; h,3.62; n,3.28.

130mL of chloroform, 10 g of silica gel (Cabot Corporation TS-610, particle size 0.05-0.5 μm) and 4mL of dichlorodimethylsilicon are added into a 250mL four-necked flask blown and discharged by nitrogen, and stirred at room temperature for 2 hours, and then 2mL of diethylaluminum chloride and 3.3 g of nickel complex Ni are added ₄ Heating to 50 ℃ under stirring, and reacting for 2 hours at constant temperature. Spray-drying the slurry obtained by using a spray dryer under spray conditions: the inlet temperature is 130 ℃, the outlet temperature is 95 ℃, and the solid catalyst component is obtained, wherein the nickel content is 1.49wt%.

(2) The ethylene slurry polymerization process was the same as in example 1 and the polymerization results are shown in Table 2.

Comparative example 1

(1) The nickel complex A1 prepared in example 1 was used without carrying out the load treatment, and found that: the unsupported catalyst can not ensure good particle form, so that the operation of the reactor is unstable, the discharge is blocked, and the reactor can only be stopped for cleaning.

(2) The nickel complex A1 prepared in example 1 was used without carrying out the supporting treatment, and it was found that the gas-phase polymerization could not be achieved.

Comparative example 2

(1) Preparation of the catalyst

1) Preparation of alkyl silicon chloride/silica gel carrier

Under the protection of nitrogen, 10.0 g of dried silica gel carrier (particle size of 30-60 um) is taken and added into a glass reactor, and then the mixture is added100 ml of dried hexane was dispersed into a suspension, and 1 ml of SiCl was added ₂ (n-Bu) ₂ Stirring is started, the temperature is raised to 30 ℃, the reaction is carried out for 4 hours, and the solid powder with good fluidity is obtained after vacuum drying.

2) Preparation of organoaluminum/alkyl silicon chloride/silica gel carrier

Under the protection of nitrogen, 5.0 g of the obtained solid powder is taken and added into a glass reactor, 60 ml of dried toluene is added, the mixture is dispersed into suspension, 18 ml of 10wt% MAO (methylaluminoxane) toluene solution is added, the temperature is raised to 50 ℃, the mixture is stirred and reacted for 4 hours, then the mixture is washed three times with 50 ml of x 3 toluene, then the mixture is washed with hexane, and the mixture is dried in vacuum, thus obtaining the solid powder with good fluidity, namely the silica gel carrier containing methylaluminoxane.

3) Preparation of Supported late transition Metal catalyst A

Under the protection of nitrogen, 2.50 g of the silica gel carrier containing the methylaluminoxane obtained above is added into a glass reactor, 35 ml of dried toluene is added to prepare slurry, and 0.36 g of Shan Huoxing center compound Ni dissolved in 20 ml of toluene is added ₁ Is added dropwise into the reactor, reacts for 30 minutes at 30 ℃, is then washed with 35 ml of toluene, and is dried in vacuum to obtain the supported transition metal catalyst A. The ICP characterization shows that in the catalyst A, the weight content of nickel is 0.27%, and the weight content of Al is 3.40%.

Comparative example 3

(1) Preparation of the catalyst

The catalyst preparation was the same as in example 3 except that the carrier modifier dichlorodimethylsilicon was not added, all the other things being equal.

Spray-drying the slurry obtained by using a spray dryer under spray conditions: the inlet temperature is 140 ℃ and the outlet temperature is 102 ℃ to obtain the solid catalyst component, wherein the nickel content is 1.21wt%.

(2) Ethylene isobutane slurry polymerization was evaluated in the same manner as in example 1 and the polymerization results are shown in Table 1.

Comparative example 3 has low catalyst activity because no passivation treatment was performed, and has low bulk density of powder because of breakage during polymerization.

Comparative example 4

(1) Preparation of the catalyst

Obtaining a compound of formula A: synthetic references Macromolecules,2009,42,7789-7796.

20g of silica gel is dispersed in 300mL of chloroform, stirred uniformly, 5mL of dichlorodimethylsilicon is added, the temperature is raised to 45 ℃ and the mixture is treated for 2 hours, then 3mmol of the compound shown in the formula A is added, and the reaction is continued for 2 hours at 55 ℃. Cooling to 45 deg.C, and spray drying. Spray drying conditions: the inlet temperature is 130 ℃, the outlet temperature is 80 ℃, and the catalyst is obtained.

(2) Slurry polymerization of ethylene

1 liter of hexane was added to a 2 liter polymerization reactor purged with nitrogen, 10 ml of Methylaluminoxane (MAO) (1.53 mol/L in toluene) and 25mg of the catalyst were added simultaneously, the temperature was raised to 70℃and ethylene was added at 1.1MPa, and after 1 hour of reaction, the temperature was lowered and discharged. The polymerization results are shown in Table 1.

(3) Gas phase polymerization of ethylene

TABLE 1 evaluation results of ethylene slurry polymerization

As can be seen from the data in Table 1, compared with the unsupported (comparative example 1) or traditional large silica gel supported catalyst (comparative example 2), the catalyst prepared by the invention has higher polymerization activity and higher powder melt index under the conditions of lower polymerization temperature and equal hydrogen-ethylene ratio, thus indicating that the novel catalyst system has better low-temperature adaptability. Meanwhile, under the condition of completely adding no comonomer, the novel catalytic system can obtain the polyethylene resin with medium density, which shows that the polyethylene resin has better spontaneous branching capability. Meanwhile, the particle form is maintained after loading, so that the production can still be normally separated out in the slurry without sticking to the kettle. Unsupported catalysts do not maintain good particle morphology under slurry process conditions. Compared with other supported nickel catalysts, the novel catalytic system has greatly improved polymerization activity and has greater advantages in terms of melt index and density.

TABLE 2 evaluation results of gas phase polymerization

As can be seen from the data in Table 2, under the condition of the pilot gas-phase fluidized bed polymerization and the same lower polymerization temperature, the single-site catalyst has higher catalytic activity, the obtained resin has higher melt index and low density, and meanwhile, the powder fluidity is still maintained, and the condition of sticking the adhesive sheet is not caused. The novel catalytic system has the greatest characteristic that branching can be spontaneously induced, and low-density product production is completed.

The invention has been described in detail in connection with the specific embodiments and exemplary examples thereof, but such description is not to be construed as limiting the invention. It will be understood by those skilled in the art that various equivalent substitutions, modifications or improvements may be made to the technical solution of the present invention and its embodiments without departing from the spirit and scope of the present invention, and these fall within the scope of the present invention. The scope of the invention is defined by the appended claims.

Claims

1. A single site catalyst comprising: a single-site compound, an inorganic carrier, a carrier modifier and an organic aluminum compound, wherein the particle size of the inorganic carrier is 0.01-10 μm, and the single-site compound is selected from at least one of compounds shown in a formula I:

a formula I;

in formula I:

R ₅ -R ₈ optionally mutually looping;

m is a group VIII metal, and repeated M's are the same or different;

2. The single site catalyst of claim 1 wherein in formula I, R ₁ And R is ₂ Each independently selected from the group consisting of C1-C20 alkyl groups containing substituents, C1-C20 alkyl groups containing no substituents, C6-C20 aryl groups containing substituents, and C6-C20 aryl groups containing no substituents.

3. The single site catalyst of claim 2 wherein in formula I, R ₁ And R is ₂ Each independently selected from the structures shown in formula II, wherein the asterisks indicate the linkage to N in formula I:

II (II)

In formula II, R ¹ -R ⁵ Each independently selected from the group consisting of hydrogen, halogen, hydroxy, C1-C20 alkyl containing substituents, C1-C20 alkyl containing no substituents, C2-C20 alkenyl containing substituents, C2-C20 alkynyl containing no substituents, C3-C20 cycloalkyl containing no substituents, C1-C20 alkoxy containing no substituents, C2-C20 alkenyloxy containing substituents, C2-C20 alkenyloxy free of substituents, C2-C20 alkynyloxy free of substituents, C3-C20 cycloalkoxy free of substituents, C6-C20 aryl free of substituents, C7-C20 aralkyl free of substituents, C7-C20 alkylaryl free of substituents or C7-C20 alkylaryl free of substituents, wherein R is ¹ -R ⁵ Optionally mutually cyclic, and repeating R ¹ 、R ² 、R ³ 、R ⁴ Or R is ⁵ The same or different.

4. The single site catalyst of claim 1, wherein in formula I:

m is selected from nickel or palladium, wherein repeated M's are the same or different;

y is selected from O or S, wherein repeated Y are the same or different;

x is selected from halogen, C1-C10 alkyl containing substituent, C1-C10 alkyl containing no substituent, C1-C10 alkoxy containing substituent or C1-C10 alkoxy containing no substituent;

R ₁₂ selected from C1-C20 alkyl or substituted radicalsC1-C20 alkyl free of substituents, repeated R ₁₂ The same or different.

5. The single site catalyst of claim 4, wherein in formula I:

m is nickel;

y is O;

R ₁₂ selected from C1-C10 alkyl groups containing substituents or C1-C10 alkyl groups without substituents, R being repeated ₁₂ The same or different.

6. The single site catalyst of claim 1, wherein the single site compound is selected from at least one of the compounds of formula III:

formula III;

in formula III: r is R ¹ -R ¹¹ Each independently selected from the group consisting of hydrogen, halogen, hydroxy, C1-C20 alkyl containing substituents, C1-C20 alkyl containing no substituents, C2-C20 alkenyl containing substituents, C2-C20 alkynyl containing no substituents, C3-C20 cycloalkyl containing no substituents, C1-C20 alkoxy containing no substituents, C2-C20 alkenyloxy containing substituents, C2-C20 alkenyloxy free of substituents, C2-C20 alkynyloxy free of substituents, C3-C20 cycloalkoxy free of substituents, C6-C20 aryl free of substituents, C7-C20 aralkyl free of substituents, C7-C20 alkylaryl free of substituents or C7-C20 alkylaryl free of substituents, repeated R ¹ -R ¹¹ The same or different; m, X, Y, R in formula III ₁₂ Has the same definition as formula I.

7. The single site catalyst of claim 6 wherein the substituent is selected from the group consisting of halogen, hydroxy, unsubstituted C1-C10 alkyl, halogen substituted C1-C10 alkyl, unsubstituted C1-C10 alkoxy, and halogen substituted C1-C10 alkoxy.

8. The single site catalyst of claim 6, wherein the single site compound is selected from at least one of the following compounds 1) to 16):

1) Single active center compounds of formula III wherein R ¹ = R ³ Methyl, R ² = R ⁴ -R ⁷ = R ¹⁰ =H，R ⁸ = R ⁹ = R ¹¹ Methyl, R ₁₂ =ethyl, m=ni, y=o, x=br;

2) Single active center compounds of formula III wherein R ¹ = R ³ =ethyl, R ² = R ⁴ -R ⁷ = R ¹⁰ =H，R ⁸ = R ⁹ = R ¹¹ Methyl, R ₁₂ =ethyl, m=ni, y=o, x=br;

3) Single active center compounds of formula III wherein R ¹ = R ³ =isopropyl, R ² = R ⁴ -R ⁷ = R ¹⁰ =H，R ⁸ = R ⁹ = R ¹¹ Methyl, R ₁₂ =ethyl, m=ni, y=o, x=br;

4) Single active center compounds of formula III wherein R ¹ - R ³ Methyl, R ⁴ -R ⁷ = R ¹⁰ =H，R ⁸ = R ⁹ = R ¹¹ Methyl, R ₁₂ =ethyl, m=ni, y=o, x=br;

5) Single active center compounds of formula III wherein R ¹ = R ³ Methyl, R ² =Br，R ⁴ -R ⁷ = R ¹⁰ =H，R ⁸ = R ⁹ = R ¹¹ Methyl, R ₁₂ =ethyl, m=ni, y=o, x=br;

6) Single active center compounds of formula III wherein R ¹ = R ³ =F，R ² = R ⁴ -R ⁷ = R ¹⁰ =H，R ⁸ = R ⁹ = R ¹¹ Methyl, R ₁₂ =ethyl, m=ni, y=o, x=br;

7) Single active center compounds of formula III wherein R ¹ = R ³ =Cl，R ² = R ⁴ -R ⁷ = R ¹⁰ =H，R ⁸ = R ⁹ = R ¹¹ Methyl, R ₁₂ =ethyl, m=ni, y=o, x=br;

8) Single active center compounds of formula III wherein R ¹ = R ³ =Br，R ² = R ⁴ -R ⁷ = R ¹⁰ =H，R ⁸ = R ⁹ = R ¹¹ Methyl, R ₁₂ =ethyl, m=ni, y=o, x=br;

9) Single active center compounds of formula III wherein R ¹ = R ³ Methyl, R ² = R ⁴ -R ⁷ = R ¹⁰ =H，R ⁸ = R ⁹ = R ¹¹ Methyl, R ₁₂ Isobutyl, m=ni, y=o, x=br;

10 Single-site compounds of formula III, wherein R ¹ = R ³ =ethyl, R ² = R ⁴ -R ⁷ = R ¹⁰ =H，R ⁸ = R ⁹ = R ¹¹ Methyl, R ₁₂ Isobutyl, m=ni, y=o, x=br;

11 Single-site compounds of formula III, wherein R ¹ = R ³ =isopropyl, R ² = R ⁴ -R ⁷ = R ¹⁰ =H，R ⁸ = R ⁹ = R ¹¹ Methyl, R ₁₂ Isobutyl, m=ni, y=o, x=br;

12 Single-site compounds of formula III, wherein R ¹ - R ³ Methyl, R ⁴ -R ⁷ = R ¹⁰ =H，R ⁸ = R ⁹ = R ¹¹ Methyl, R ₁₂ Isobutyl, m=ni, y=o, x=br;

13 Single-site compounds of formula III, wherein R ¹ = R ³ Methyl, R ² =Br，R ⁴ -R ⁷ = R ¹⁰ =H，R ⁸ = R ⁹ = R ¹¹ Methyl group =methyl group，R ₁₂ Isobutyl, m=ni, y=o, x=br;

14 Single-site compounds of formula III, wherein R ¹ = R ³ =F，R ² = R ⁴ -R ⁷ = R ¹⁰ =H，R ⁸ = R ⁹ = R ¹¹ Methyl, R ₁₂ Isobutyl, m=ni, y=o, x=br;

15 Single-site compounds of formula III, wherein R ¹ = R ³ =Cl，R ² = R ⁴ -R ⁷ = R ¹⁰ =H，R ⁸ = R ⁹ = R ¹¹ Methyl, R ₁₂ Isobutyl, m=ni, y=o, x=br;

16 Single-site compounds of formula III, wherein R ¹ = R ³ =Br，R ² = R ⁴ -R ⁷ = R ¹⁰ =H，R ⁸ = R ⁹ = R ¹¹ Methyl, R ₁₂ Isobutyl, m=ni, y=o, x=br;

17 Single-site compounds of formula III, wherein R ¹ = R ³ Methyl, R ² = R ⁴ -R ⁷ = R ¹⁰ =H，R ⁸ = R ⁹ Methyl, R ¹¹ Bromomethyl group, R ₁₂ =ethyl, m=ni, y=o, x=br;

18 Single-site compounds of formula III, wherein R ¹ = R ³ =ethyl, R ² = R ⁴ -R ⁷ = R ¹⁰ =H，R ⁸ = R ⁹ Methyl, R ¹¹ Bromomethyl group, R ₁₂ =ethyl, m=ni, y=o, x=br;

19 Single-site compounds of formula III, wherein R ¹ = R ³ =isopropyl, R ² = R ⁴ -R ⁷ = R ¹⁰ =H，R ⁸ = R ⁹ Methyl, R ¹¹ Bromomethyl group, R ₁₂ =ethyl, m=ni, y=o, x=br;

20 Single-site compounds of formula III, wherein R ¹ - R ³ Methyl, R ⁴ -R ⁷ = R ¹⁰ =H，R ⁸ = R ⁹ Methyl, R ¹¹ =bromoMethyl, R ₁₂ =ethyl, m=ni, y=o, x=br;

21 Single-site compounds of formula III, wherein R ¹ = R ³ Methyl, R ² =Br，R ⁴ -R ⁷ = R ¹⁰ =H，R ⁸ = R ⁹ Methyl, R ¹¹ Bromomethyl group, R ₁₂ =ethyl, m=ni, y=o, x=br;

22 Single-site compounds of formula III, wherein R ¹ = R ³ =F，R ² = R ⁴ -R ⁷ = R ¹⁰ =H，R ⁸ = R ⁹ Methyl, R ¹¹ Bromomethyl group, R ₁₂ =ethyl, m=ni, y=o, x=br;

23 Single-site compounds of formula III, wherein R ¹ = R ³ =Cl，R ² = R ⁴ -R ⁷ = R ¹⁰ =H，R ⁸ = R ⁹ Methyl, R ¹¹ Bromomethyl group, R ₁₂ =ethyl, m=ni, y=o, x=br;

24 Single-site compounds of formula III, wherein R ¹ = R ³ =Br，R ² = R ⁴ -R ⁷ = R ¹⁰ =H，R ⁸ = R ⁹ Methyl, R ¹¹ Bromomethyl group, R ₁₂ =ethyl, m=ni, y=o, x=br.

9. The single site catalyst of claim 1, wherein the catalyst is,

the inorganic carrier is oxide of silicon and/or aluminum; and/or the number of the groups of groups,

the carrier modifier is halogenated silane; and/or the number of the groups of groups,

the organoaluminum compound is selected from the group consisting of compounds of the general formula A1R ^c _n X'' _3-n At least one of the compounds of (1), wherein R ^c Selected from hydrogen or C1-C20 hydrocarbon radicals, X '' is halogen, n is more than 0 and less than or equal to 3.

10. The single site catalyst of claim 9, wherein the catalyst is,

the particle size of the inorganic carrier is 0.02-5 mu m; and/or the number of the groups of groups,

the general formula of the carrier modifier is SiR ^a R ^b X' _x Wherein R is ^a And R is ^b Selected from hydrogen, C1-C10 alkyl or halogen independently, X' represents halogen, x.gtoreq.2.

11. The single-site catalyst according to one of claims 1 to 10, characterized in that the content of the inorganic carrier is 30 to 70wt%, the content of the carrier modifier is 10 to 40wt%, the content of the organoaluminum compound is 0.5 to 15wt%, and the content of the single-site compound is 0.05 to 4wt%, based on 100wt% of the total weight of all components, wherein the content of the single-site compound is calculated based on the content of the metal element M therein.

12. A method of preparing the single site catalyst of any one of claims 1 to 11, comprising: mixing the inorganic carrier, the carrier modifier, the organic aluminum compound and the single-site compound with a solvent, and then performing spray drying to obtain the single-site catalyst.

13. The method according to claim 12, wherein,

the mixing is carried out at 20-90 ℃; and/or the number of the groups of groups,

cooling the mixed materials before spray drying; and/or the number of the groups of groups,

the spray drying conditions are as follows: the inlet temperature is 60-240 ℃; the outlet temperature is 60-130 ℃.

14. The production method according to claim 12 or 13, wherein the content of the inorganic carrier is 1 to 20wt%, the content of the carrier modifier is 0.5 to 6wt%, the content of the organoaluminum compound is 0.01 to 5wt%, and the content of the single-site compound is 0.01 to 4wt%, wherein the content of the single-site compound is calculated based on the content of the metal element M therein.

15. A single site catalyst obtainable by the process of any one of claims 12 to 14.

16. A composite catalyst for olefin polymerization comprising an organoaluminum catalyst and the single-site catalyst according to any one of claims 1 to 11 or claim 15; the molar ratio of aluminum in the organoaluminum catalyst to metal M in the single-site catalyst is (5-500): 1.

17. The composite catalyst of claim 16, wherein the organoaluminum catalyst is selected from the group consisting of A1R ^d _m X''' _3-m At least one of the compounds of (1), wherein R ^d Selected from hydrogen or C ₁ -C ₂₀ X ' ' ' is halogen, m is more than 0 and less than or equal to 3.

18. The composite catalyst according to claim 16, wherein the molar ratio of aluminum in the organoaluminum catalyst to metal M in the single-site catalyst is (10-200): 1.