The catalyst for polymerization of olefins as sabreliner metal complexes and method for producing poly--olefin (options)

 

(57) Abstract:

Describes a new catalyst for the polymerization of olefins in the form of sabreliner metal complexes of General formula (I), where L is a ligand of formula (II), where L' is cyclopentadienyl, pentamethylcyclopentadienyl; X is halogen, M is titanium, zirconium or hafnium; R1- alkyl, C1-C12; R2- alkyl, C1-C12; R3is hydrogen, n = 0, 1, 2, 3; Lin- the optional Lewis base. Also described is a method of obtaining poly-olefin (options). The technical result is an increase in the activity of the catalyst and the possibility of its use in very small quantities. 3 S. and 12 C.p. f-crystals, 4 PL.

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The invention relates to catalysts used for Homo - and copolymerization of ethylene and other olefin hydrocarbons. In particular, the invention relates to catalysts containing a transition metal, connected-connection with ligand containing zabronirovat ring.

To date, polyolefins received a direct method using a conventional catalytic system of the Ziegler. These catalysts usually consist of transition metal compounds and one or more ORGANOMETALLIC compounds. Mini chloride or a mixture of titanium tetrachloride, oxytrichloride vanadium and triethylaluminum. The cost of such catalysts is low, however, they are characterized by low activity, resulting in the need to use them at high concentrations. The result is sometimes necessary to remove the remaining catalyst from the polymer, which greatly increases the cost of the product. To eliminate the negative impact of the admixture of the catalyst, it is necessary to add a neutralizing agents and stabilizers. If you cannot remove the residual catalyst in the polymer, it leads to yellow, or gray staining of the polymer, as well as lower resistance to ultraviolet radiation and stability in time. For example, the presence of chlorine-containing impurities can cause corrosion of the equipment for processing of the polymer. Moreover, the use of Ziegler catalysts results in a polymer with a broad molecular weight distribution, that in some cases the use of the polymer is undesirable, for example when forming the molding. The use of a catalyst of Ziegler does not provide a sufficiently high degree of introduction of comonomers-olefins, which does not allow to control the density of the polymer. To Poer. When this reaches a very low level of injection, or even impossible the introduction of many higher-olefins such as 1-octene.

Despite the fact that after the invention of the catalytic system of the Ziegler, it was much improved, at present, these catalysts are replaced with the newly developed catalytic system containing metallocene. Usually the composition of these catalysts include transition metal compound that contains one or more cyclopentadienyls ring ligands. The catalysts of the Ziegler-based mixture metallocenes with ORGANOMETALLIC compounds, such as trialkylaluminium, which are used in conventional Ziegler catalysts have low activity. However, a mixture metallocenes with luminokaya as socializaton shows very high activity. The activity of the latter is so high that there is no need for removal of catalyst residues from the polymer. Moreover, the use of catalysts containing metallocene, allows to obtain high molecular weight polymers with narrow molecular weight distribution. Thus attain a high degree of introduction as comonomers-olefins. However, the use of cat is polimerov. Thus, these catalysts applicable for polymerization of ethylene in the gas phase or in emulsion, the polymerization process is carried out at 80-95oC. However, these catalysts are practically not active in the polymerization of ethylene in solution at a temperature of from about 150 to 250oC. Polymerization of ethylene in solution is preferred as it provides for the production of polymer in a wide range of molecular weight and density, and also allows you to use a wide variety of different comonomers. Polymerization in solution also allows one to obtain polymers that can be used in various fields. For example, can be obtained as polyethylene (PE) with high molecular weight and high density, used as a protective film for food packaging, and copolymers of ethylene with low density, high strength and high toughness.

We have found a new class of catalysts based on compounds with the structure seborainogo ring containing transition metals. The catalysts according to the invention are characterized by an extremely high activity and, therefore, they can be used in very small colicinogenic catalysts at higher temperatures suggests, they can be used in the polymerization of ethylene in solution.

We also found that the sensitivity of the monomers in the polymerization process in the presence of catalysts according to the invention with respect to hydrogen is much higher compared with other catalysts. In this connection, when the polymerization of the monomers in the presence of catalysts according to eobrien slight change of hydrogen content in the reaction mixture has a significant influence on the molecular weight of the resulting polymer.

The catalysts according to the invention are characterized by the General formula

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where L is a ligand of the formula

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where L' is L, Cp, Cp', indenyl, fluorenyl, NR2, Or, or halogen, L may be associated with L' bridge bond, X represents halogen, NR2, Or, or alkyl (C1-C12, M stands for titanium, zirconium or hafnium, R means alkyl, C1-C12or aryl (C6-C12, R1means R, alkaryl C6-C12aralkyl C6-C12hydrogen or Si(R)3, R2means R1, halogen, COR, COOR, SOR, or SOOR, R3means R2, OR, N(R)2, SR or condensed cyclic system, Cp denotes a cyclopentadienyl, Cp' means pentia possess high activity and easy to get. The group X is preferably halogen and most preferably chlorine, as these connections more accessible. The group R preferably is an alkyl (C1-C4the group R1preferably is alkyl (C3-C12or aryl group, R2is preferably tert-bootrom or trimethylsilyl and R3is preferably hydrogen or stands, as these compounds are easier to get. Examples of the group R3containing condensed ring, may be represented by the following formula:

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The metal M preferably represents zirconium as zirconium catalysts combine high activity with stability.

The selection group L may be associated with a group L' bridge. As a group forming a bridge of communication with both ligands, can be used methylene, ethylene, 1,2-phenylene, dimethylsilane, dietildisul, divinycell and methylpenicillin. Typically, the catalyst contains only one bridge. Assume that bridge communication with ligands alters the geometry of the structure around the catalytically active transition metal atom, which leads to an increase of catalytic activity and in the General formula optional can mean a Lewis base, which added to the reaction mixture until the equimolar amount (relative to M). Use base Lewis mostly undesirable, as it leads to loss of catalytic activity. However, the inclusion of the base Lewis in the composition of the catalyst increases its stability and, thus, the inclusion of the base Lewis may be appropriate depending on the particular polymerization process, in which the used catalyst. As a basis you can use the solvent remaining after receiving sabreliners connection or base can be added separately to increase the stability of the catalyst. For example, as the base can be used ethers such as diethyl ether, disutility ether, tetrahydrofuran, 1,2-dimethoxyethane, esters, such as n-butylphthalate, ethylbenzoic and ethyl-p-anizat, tertiary amines such as triethylamine and phosphines such as triethylphosphine, tributylphosphine and triphenylphosphine.

The catalysts according to the invention can be obtained by using a commercial source connections. Specific starting compound, commiee. Predecessor sabreliners ligand is produced by the interaction of dianion allylamine (which is formed from allylamine in the presence of a strong base) with alkylhalogenide boron (J. Schulze, G. Schmidt, J. were obtained. Chem., 1980, 193, p.83).

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As strong bases can be used compounds of the alkyl lithium such as n-utility, motility and hydrides, such as sodium hydride and potassium hydride. To pray one of allylamine add two mole of base. The reaction is carried out at room temperature for several hours in a hydrocarbon solvent such as pentane or hexane. To stabilize alkylate to allylamino add tetramethylethylene in a molar ratio of 1:1. The reaction product can be isolated under vacuum and purified by distillation.

The next stage, described in the literature, is the interaction of the resulting product with a base, such as lithium compound with a complicated spatial structure, for example with tetramethylpiperidine lithium. The result is zabronienie (G. Schmidt et al., Chem. Ber., 1982, 115, p. 3830):

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The final stage is the cooling of the product obtained in the second stage, to (-60)oC and adding MX4and MCpX3LiX precipitates:

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where

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As is usually the catalyst is used in combination with ORGANOMETALLIC socialization, it is preferable to use a solvent which will dissolve both the catalyst. For example, if socialization is methylaluminoxane (MAO), then the solvent can be used toluene, xylene, benzene or ethylbenzene. Other suitable socialization are compounds alkylamine General formula AlR'x(R2)3-xwhere 1<x<3 and R2is hydrogen, halogen, or alkyl or alkoxide C1-C20such as triethylaluminium and dichloride ethylaluminum. It is preferable MAO, because the use of such socializaton results in a highly active catalytic systems and polymer with a narrow molecular weight distribution. The molar ratio of ORGANOMETALLIC socializaton to the catalyst during polymerization is usually from 0.1:1 to 100,000:1, preferably from 1:1 to 10000:1.

Alternative socialization is acidic Sol containing coordinational inert anion (see U.S. patent N 5064802). Usually the acid salt is dinucleophiles compound containing bulky ligands, connec henyl) aluminate, aniline tetrakis(pentafluorophenyl)borate, N,N-dimethylanilinium tetrakis(pentafluorophenyl)borate, triliterals(pentafluorophenyl)borate or mixtures thereof. Assume that in the interaction of these compounds with a catalyst formed anion, which forms subcoordinators connection with metal-containing cation. The molar ratio of the acid salt to the catalyst can range from 0.01: 1 to 1000:1, preferably from 1:1 to 10:1. Although there are no specific limitations to the method of obtaining the active catalytic system comprising a catalyst and an acidic salt, preferably you should mix them in an inert solvent at a temperature of from about (-78)oC to about 150oC. If necessary, they can be mixed in the presence of monomer. Acid salt can be used in combination with ORGANOMETALLIC acetalization described earlier.

The catalyst and acetalization can be used on a solid carrier such as silica gel, aluminum oxide, silicon dioxide, magnesium oxide or titanium oxide. However, the use of media undesirable, as they can be a source of impurities in the polymer. At the same time, the need to use media depends on the method of polymerization is to the particle size of the resulting polymer and to prevent contamination of the walls of the reactor. The use of media can also increase thermal stability of the catalyst. The catalyst on the carrier is obtained by dissolving the catalyst and socializaton in the solvent and their deposition on the carrier, for example by evaporation of the solvent. Acetalization you can either precipitate on the carrier, or to be added to the reactor separately from the catalyst on the carrier.

The catalyst should be used as soon as possible after receipt, because the activity may decrease during storage. The catalyst should be stored at low temperatures, such as from (-100)oC to about 20oC. the Catalyst used method conventional in the polymerization of olefinic hydrocarbon monomers. Despite the fact that the catalyst obtained according to the invention, can be used for the polymerization of unsaturated monomers, such as styrene, these catalysts are particularly effective in the polymerization of olefins, such as propylene, 1-butylene, 1-hexene, 1-octene, and especially ethylene.

The catalyst may also be used for copolymerization of mixtures of unsaturated monomers such as ethylene, propylene, 1-butene, 1-hexene, 1-octene, and the like; mixtures of ethylene and diolefines is, such as norbornene, ethylidenenorbornene, vinylnorbornene, norbornadiene and the like. The catalysts obtained according to the invention can be used in various polymerization processes.

The catalysts can be used for polymerization in the liquid phase (emulsion, solution, suspension, bulk or in combination), in the liquid phase at high pressure or polymerization in the gas phase. The polymerization process may be single or multiple processes. The pressure in the reaction zone of the polymerization can vary from about 15 psia to approximately 50,000 psia and the temperature is approximately from (-100)oC to 300oC. the Following examples illustrate the invention.

EXAMPLE 1

Obtaining bis(1-tert-butyl-2-methyl-5-1,2-sabreliner)zirconium dichloride and (1-tert-butyl-2-methyl-5-1,2-sabreliner)Zirconia trichloride

To obtain 2-methyl-1-tert-butyl-1,2-sabreliner lithium solution prepared 0,438 g (3.2 mmol) of 2-methyl-1-tert-butyl-3-1,2-sabreline (obtained by the method of J. Schultze and G. Schmid: J. were obtained. Chem. 1980, 193, 83-91) in 6 ml of dry tetrahydrofuran (THF) and added dropwise at -78)oC to a solution of 2,2,6,6-tetramethylpiperidine lithium (3.2 mmol, poona in 10 ml of tetrahydrofuran (THF). Cool the mixture in a bath heated to 10oC for 1.5 h, after which the solvent is distilled off in vacuum. The yellow oily residue is treated with 35 ml of toluene and receives a yellow emulsion, which is cooled to (-60)oC, and type of 0.37 g (1.6 mmol) of the chloride of zirconium (IV) under vigorous stirring. The mixture in the bath warmed to room temperature and the reaction mixture stirred over night. The solvent is distilled off in vacuum, the residue is treated with 30 ml of toluene and filtered from lithium chloride. Toluene, the filtrate evaporated, sticky yellow residue extracted with hexane (2 x 15 ml) and filtered. After evaporation of the hexane filtrate obtain 0.14 g of yellow solid product. According to the1H NMR of the resulting product contains a mixture of two essential compounds in the ratio 2:3.

EXAMPLE 2

Receive (5-cyclopentadienyl)(1-tert-butyl-2-methyl-5-1,2-sabreliner)zirconium dichloride

METHOD AND

0,49 g (3.5 mmol) of 2-methyl-1-tert-butyl-3-1,2-sabreline dissolved in 20 ml of THF and get a solution of 2-methyl-1-tert-butyl-1,2-sabreliner lithium as described above. This solution is added dropwise via syringe with stirring to a cooled to (-35)oC to a solution of 0.9, actionnow the mixture is stirred over night. The solvent is distilled off in vacuum, the residue is extracted with 35 ml of toluene and filtered. The precipitate was washed with 10 ml toluene and the combined filtrates evaporated. By mixing the yellow sticky residue with 25 ml of dry hexane get a beige solid and light yellow supernatant. After filtration and drying the precipitate gain of 0.77 g of product as a tan amorphous powder. According to the1H NMR necessary product contains a number of impurities.

METHOD B

2-Methyl-1-tert-butyl-1,2-sabreliner Li is obtained by adding 0,438 g (3.2 mmol) of 2-methyl-1-tert-butyl-3-1,2-sabreline (obtained by the method of J. Shultze and G. Schmid, J. were obtained. Chem., 1980, 193, 83-91) in 10 ml of dry toluene cooled to to (-78)oC to a solution of 2,2,6,6-tetramethylpiperidine lithium (3.2 mmol) obtained in the interaction equimolar amounts of 2,2,6,6-tetramethylpiperidine and n-utility/hexane, 15 ml of THF. The solvent is distilled off in vacuo to 1/3 of the initial volume, the solution is cooled to (-78)oC and add 35 ml of dry toluene. In the resulting clear yellow solution serves for connecting the tube 0.84 g (3.2 mmol) cyclopentadienylcobalt during the night. The reaction mixture is filtered, the filtrate is evaporated to obtain a dry residue. To the solid residue is added 20 ml of toluene, followed by filtration, the yellow filtrate is separated from the dark insoluble precipitate. After evaporation of the filtrate obtain 0.34 g of a yellow amorphous powder, 1H NMR spectrum of which corresponds to the range of the required product.

EXAMPLES 3-11

Polymerization of ethylene in sabreliner zirconium catalysts

Ethylene will polimerizuet using the catalyst obtained in accordance with method A of example 2. The polymerization is carried out in an autoclave with a volume of 1.7 liters, equipped with a mixer at 80-110oC. 840 ml of dry, not containing oxygen toluene load in a clean, dry, containing no oxygen reactor. For polymerization using 10 wt.% solution in toluene MAO (company Ethyl Corporation). To obtain the desired ratio specified in the table below, the required number of MAO added via syringe at 30oC. the Reactor is heated to the required temperature and add ethylene in an amount sufficient to establish in the reactor pressure to 150 psig. The reactor balance at the required temperature and pressure. The solution of catalyst was prepared tor. To initiate polymerization using a certain amount of this solution, containing specified in the table number of the catalyst. In the process of obtaining the polymer in the reactor to maintain a constant pressure of 150 psig by feeding it, as necessary, the flow of ethylene.

By the end of 1 hour (or less, if the activity is very high), the flow of ethylene was stopped and the reactor was rapidly cooled to room temperature. The reactor was opened and the polymer is filtered from the toluene. The product is dried in a vacuum drying Cabinet overnight and weighed. Table 1 shows the conditions of the reaction, and the polymerization results are presented in table 2.

The melt index of the polymer is determined in accordance with ASTM D-1238, mode E mode f M - melt index, determined at a load of 2.16 kg (mode E). M - melt index, determined at a load of 21.6 kg (F). MFR is the ratio M to M. The density of the polymer is determined in accordance with ASTM D-1505. Molecular weight distribution of the polymer was determined using gel-penetrating chromatography on a Waters chromatograph 150 C for 135oC, using as solvent 1,2,4-trichlorobenzene. To characterize mol is /Mn(Brednikova molecular weight).

Table 2 shows that using the proposed in this invention catalysts receive polymers with a wide range of molecular masses, since these catalysts are sensitive to hydrogen.

EXAMPLES 12 and 13

Polymerization in solution is carried out in a stainless steel autoclave with a volume of 2.0 liters, equipped with a mixer at 150oC. 1.0 l of dry, not containing oxygen ISOPAR G(company Exxon Chemical Company) is loaded into a clean, dry, containing no oxygen reactor. Then the reactor balance at 150oC. By submitting a sufficient amount of ethylene in the reactor establish a partial pressure of 150 psig. Hydrogen or comonomers not add. The solution of catalyst, the receipt of which is described in example 2, is mixed with 10% solution methylaluminoxane (MAO) in toluene (reagent company Albemarle Corporation used without further purification). The mixture is stirred for 15 minutes To initiate polymerization in the reactor is injected 10 ml of the mixture. Table 3 shows the amount of catalyst and MAO contained in 10.0 ml of the mixture and the conditions of the polymerization. By feeding ethylene in the ion mixture is transferred into a vessel, containing a solution of the antioxidant in Isopar G. The solution is cooled to room temperature over night. Filtration in vacuum, the polymer is separated from the solvent, dried in a vacuum drying Cabinet overnight and weighed. The weight of the polymer is 12.1 MI2, the obtained polymer is 118 g/min Additional characteristics of the obtained polymer are shown in table 2.

EXAMPLES 14-18

Emulsion polymerization is conducted similarly to the method described in examples 3-11. Using the catalyst, the receipt of which is described in example 1. The conditions of the polymerization are shown in table 3. Properties of the obtained polymers are shown in table 4.

The table below shows that the catalyst has high activity and produces a polymer with a high degree of crystallinity and density. Low MFR values indicate that the polymer has a narrow molecular weight distribution.

1. The catalyst for polymerization of olefins as sabreliner metal complexes of General formula (I)

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where L is a ligand of formula (II)

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L' - cyclopentadienyl, pentamethylcyclopentadienyl;

X is halogen;

M is titanium, UB> is hydrogen;

n= 0, 1, 2, 3;

Lin- the optional Lewis base.

2. The catalyst p. 1, wherein the ligand L' is a cyclopentadienyl or pentamethylcyclopentadienyl, X is chlorine, M is zirconium, R1- alkyl, C3- C12, R2tert-butyl, R3- hydrogen.

3. The catalyst p. 1, characterized in that it is a (1-tert-butyl-2-methyl-n5-1,2-sabreliner)zirconium trichloride.

4. The catalyst p. 1, wherein M is zirconium.

5. The method of obtaining poly-olefin, comprising polymerization --olefin monomer in the presence of a catalyst in the form of asaboriginal complex metal, wherein the used catalyst under item 1.

6. The method according to p. 5, characterized in that the polymerization is carried out in the presence of a catalyst indicated formula in which X is chlorine.

7. The method according to p. 5, characterized in that the polymerization is carried out in the presence of a catalyst indicated formula in which M is zirconium.

8. The method according to p. 5, characterized in that the polymerization is carried out in the presence of a catalyst indicated formula in which R1- alkyl, C3- C12.

9. The method according to p. 5, characterized in that Thu is merisalu carried out in the presence of a mixture of the catalyst with an ORGANOMETALLIC socialization, containing 0.01 to 100000,0 mol socializaton on 1 mol of the specified catalyst.

11. The method according to p. 10, characterized in that as ORGANOMETALLIC socializaton use methylalumoxane.

12. The method according to p. 5, characterized in that the polymerization is carried out in the presence of a mixture of the catalyst with acidic salt containing coordinational inert anion, when its content in the mixture is about 0.01 - 100000,0 mol per 1 mol of the specified catalyst.

13. The method according to p. 12, wherein the acid salt is a compound selected from the group comprising lithium tetrakis (pentafluorophenyl)borate, lithium tetrakis (pentafluorophenyl)aluminate, aniline tetrakis (pentafluorophenyl)borate, N,N-dimethylanilinium tetrakis (pentafluorophenyl)borate, trityl tetrakis (pentafluorophenyl)borate or mixtures thereof.

14. The method of obtaining poly-olefin, comprising the polymerization is altinboga monomer in the presence of a catalyst in the form of zabronionego complex metal, characterized in that the use of the catalyst of General formula

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where L is a ligand of the formula

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L' is a cyclopentadienyl or pentamethylcyclopentadienyl;

X is chlorine;

M is zirconium;

R1- alkyl, C3-warping Lewis.

15. The method according to p. 14, characterized in that the catalyst is a (1-tert-butyl-2-methyl-n5-1,2-sabreliner)zirconium trichloride.

 

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