The catalytic system, the method of polymerization of ethylene and the polymerization method, a linear or branched-olefins

 

(57) Abstract:

Describes a new catalytic system for polymerization of olefins, comprising socialization and catalyst, which contains the compound of the transition metal 4 groups and at least one bidentate ligand. Honours system is used as a bidentate ligand residue xenolinux or pyridyloxy General formula (I) or (II) where Y represents O, M stands for titanium, zirconium, or hafnium; each X is independently from each other halogen, L means X, cyclopentadienyl or a residue of formula (III), where each R' is independently from each other H, alkyl (C1-C6or halogen. Describes the method of polymerization of ethylene and the polymerization method, a linear or branched olefins. The technical result is an increase in the activity of the catalytic system, the possibility of obtaining high molecular weight polymers with narrow molecular weight distribution with a sufficient degree of incorporation into the polymer-olefin comonomers. 3 S. and 4 C.p. f-crystals, 2 PL.

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The technical field to which the invention relates.

The present invention relates to catalysts used is eat catalysts based on transition metals and bidentate ligands, containing residues of pyridine or quinoline.

Art

Unlike the products of the reaction described in U.S. patent N 3900452, in which the titanium atom in connection TiCl3-peridinin linked to the nitrogen atom of the heterocycle communication other than Sigma-communication, connection, according to the present invention contain titanium atom linked to the nitrogen atom bond, which is not a σ-bond, and the associated σ-bond with the oxygen atom connected to the heterocycle.

To date, the polyolefins are usually received with use of known catalytic system of the Ziegler. Typical Ziegler catalyst composed of a transition metal compounds and one or more ORGANOMETALLIC compounds. For example, the polyethylene was obtained with the use of Ziegler catalysts, such as trichloride titanium and diethylaluminium 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 residual catalyst in the polymer leads to yellow, or gray staining of the polymer, as well as lower estoit can cause corrosion of equipment for polymer processing. In some cases, to eliminate the negative impact of the admixture of the catalyst, you must either delete the admixture of catalyst from the polymer or added to the polymer neutralizing agents and stabilizers, which significantly increases the cost of the product. Moreover, the use of Ziegler catalysts results in a polymer with a broad molecular weight distribution, which in some cases is undesirable, for example, the molded products by injection molding. The use of a catalyst of Ziegler does not provide a sufficiently high degree of introduction-olefin comonomers, making it difficult to control the density of the polymer. To obtain a polymer of a certain density, it is necessary to use an excessive amount of co monomer, yielding a very low degree of introduction of many higher-olefins such as 1-octene, or their introduction is not achieved at all.

Despite the fact that after the invention of the catalytic system of the Ziegler was significantly improved, at present, these catalysts are replaced with the newly developed catalytic system containing metallocene. Usually, the composition of these catalysts include transition connection Alonenow with ORGANOMETALLIC compounds, such as alkylamine, which are used in conventional Ziegler catalysts have low activity. However, a mixture metallocenes with alumoxane as socializaton shows very high activity. The activity of the latter is usually 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, there is a sufficient degree of incorporation into the polymer-olefin comonomers.

However, the use of catalysts containing metallocene, at higher temperatures results in low molecular weight polymers. Thus, these catalysts applicable for polymerization of ethylene in the gas and particle phase, when the polymerization process is carried out at 80-95oC. However, when the temperature increases, these catalysts are not active. Polymerization of ethylene in solution at higher temperatures is preferred because it provides the possibility of obtaining a polymer with a wide range of molecular weight and density, as well as allowing a wide choice raslani 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 toughness.

The invention

The invention presents a catalytic system for the polymerization of olefins, comprising socialization and catalyst, which contains the compound of the transition metal 4 groups and at least one bidentate ligand, and the specified bidentate ligand contains the remainder of xenolinux or pyridyloxy General formula:

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where Y represents O, M means titanium, zirconium or hafnium; each X is, independently of one another, halogen, L means X, cyclopentadienyl or

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each R' represents, independently of one another, H, alkyl (C1-C6or halogen.

We opened a new complex compounds of transition metals containing bidentate ligands based on pyridine, which is highly active catalysts for the polymerization of olefins. We have discovered that compounds of transition metals containing bidentate ligand on the basis of the quinoline who isatori polymerization. The use of these catalysts allows to obtain polymers with properties similar to the properties of the polymers produced using metallocene catalysts, i.e. with a narrow molecular weight distribution and uniform introduction of comonomers.

Information confirming the possibility of carrying out the invention

The catalysts according to the invention containing a transition metal and pyridine as a bidentate ligand, have the General formula:

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where Y represents O, each R', independently of one another, denotes H, alkyl (C1-C6, halogen; M means titanium, zirconium or hafnium; each X, independently of one another, denotes halogen; L means X, cyclopentadienyl or

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In this formula, the group Y is oxygen, since such compounds are easier to get. For the same reason, R' is preferably hydrogen. The group L is preferably a halogen, most preferably chlorine, since such catalysts are the most effective and also easier to obtain. For the same reasons, the group X is a halogen, especially chlorine, and group M is preferably titanium.

A method of obtaining a bidentate complexes feast is Estonica pyridine, containing acidic proton, with the compound of the formula MX3L in the presence of acceptor HX. The reaction proceeds stoichiometrically, and it is preferred stoichiometric amount of the acceptor. Examples of suitable acceptors are compounds with a higher basicity than substituted pyridines, such as triethylamine, pyridine, sodium hydride and butyl lithium. If you use the acceptor with a higher basicity than the substituted pyridine, you can get a salt of the substituted pyridine and use it as the source connection. Although the reaction is preferably carried out in a solvent, is required only partial solubility of the reagents. As the aprotic solvent can be used tetrahydrofuran (THF), ether, toluene or xylene at a concentration of solids of from about 0.2 to about 20 wt.% in the calculation of the solid substance, preferably from 5 to 10 wt. %. The reaction can be carried out at a temperature of from -78)oC to room temperature. During the reaction, a precipitate, and the reaction product can be extracted with toluene, methylene chloride, diethyl ether or similar extractant.

The catalysts according to the invention, representing a complex is th formula:

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where R', L, M, and X have the same meaning as in the above formula.

The catalysts of transition metal compounds with bidentate ligands based on quinoline receive in a manner analogous to obtaining a catalyst with bidentate ligands based on pyridine, except that as the starting compound instead of the substituted pyridine use of substituted quinoline, such as 8-hydroxyquinoline (known as 8-hinolinol). As starting compounds can also use lithium salt of 8-hydroxyquinoline solution, which is obtained using utility in solvent.

As is usually the catalyst is used in combination with ORGANOMETALLIC socialization, it is preferable to use a solvent which is soluble as a catalyst, and socialization. For example, if socialization is methylalumoxane (MAO) or polymethylsiloxane (PMAO), then the solvent can be used toluene, xylene, benzene or ethylbenzene. The preferred acetalization MAO is because the use of such socializaton results in a highly active catalytic systems and polymer with a narrow molecular weight distribution. Mole,01:1 to 100000:1, 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 attached to the boron atom or aluminum atom, such as lithium tetrakis(pentafluorophenyl) aluminate, aniline tetrakis(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 particular restrictions on the method of obtaining the active catalytic system comprising a catalyst and an acidic salt, preferably they are mixed 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 medium such as the EES is not preferred, because they can be a source of impurities in the polymer. At the same time, you may need to use media depending on the particular method of polymerization. For example, the use of media may be required for polymerization in the gas phase and particle phase to control the particle size of the resulting polymer and prevent contamination of the walls of the reactor. The catalyst on the carrier is obtained by dissolving the catalyst and socializaton in the solvent and their deposition on the material of the carrier, for example, by evaporation of the solvent. Socialization can also be supported on a carrier or it can be introduced into the reactor separately from the catalyst on the carrier.

The catalyst used in the usual way used in the polymerization of olefinic hydrocarbon monomers. Although 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-butene, 1-hexene, 1-octene and especially ethylene.

The catalyst can also be used in the usual manner by copolymerization of mixtures of unsaturated monomers, tadian, 1,4-hexadiene, 1,5-hexadiene and the like; and mixtures of ethylene and unsaturated comonomers, such as norbornene, ethylidenenorbornene, vinylnorbornene, norbornadiene and the like.

The catalysts according to the invention can be used in various polymerization processes. They can be used in the polymerization in the liquid phase (slurry (slurry, solution, suspension, loose weight, or a combination), in the liquid phase at high pressure or polymerization in the gas phase. The polymerization process may be a single or a series of processes. The pressure in the reaction zone of the polymerization may range from about 103,42 kPa to about 344750 kPa, the temperature is from about (-78)oC to about 300oC.

EXAMPLE 1

Synthesis of bis(2-pyridyloxy)titanium dichloride

To a solution of 0.02 mol of 2-hydroxypyridine and 0.02 mol of triethylamine in 50 ml tetrahydrofuran (THF) is added dropwise a solution of 0.01 mol of titanium tetrachloride at 0oC and stirred over night at room temperature. After filtration of the solution THF evaporated and the residue extracted with the reaction product with the following formula:

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EXAMPLE 2

Receiving (cyclopentadienyl)(2-pyridyloxy)titanium dichloride

RA is and triethylamine (0.002 mol) in 50 ml ether at 0oC and stirred overnight. The product is recovered from the ether filtrate. The product formula II below.

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EXAMPLE 3

The main way to obtain catalysts based on transition metal compounds and oksihinolina

A suspension of lithium salts of various derivatives of 8-chinoline (obtained using utility) in toluene is mixed at (-78)oC with the appropriate compound of titanium or zirconium (titanium tetrachloride, zirconium tetrachloride, cyclopentadienide trichloride or cyclopentadienyl zirconium trichloride) and stirred over night at room temperature. The complexes are separated from the reaction mixture by extraction with toluene or methylene chloride. To obtain 8-oksikhinolinata of trichloride (III)

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to a solution of 1.9 g (0.01 mol) TiCl4in 20 ml of toluene was added when (-78)oC a suspension of 0.01 mol of the lithium salt of 8-hydroxyquinoline solution in 30 ml of toluene (obtained from 1.45 g (0.01 mol) of chinoline and MeLi) and stirred over night at room temperature. The precipitate was separated, washed with toluene and extracted with 100 ml of CH2Cl2. After removal of the methylene chloride receive a brown microcrystalline product (0.7 g).

Similarly receive is inane use lithium salt, obtained from 2.28 g (0.01 mol) of 5,7-dichloro-2-methyl-8-chinoline.

A similar method is used to obtain 1.0 g of the complex, bis[8-(2-methyl-5,7-dichlorohydrin)oxy]zirconium dichloride (V) to compare

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It is derived from 2.28 g (0.01 mol) of 5,7-dichloro-2-methyl-8-chinoline and 1,165 g (0,005 mol) of zirconium tetrachloride.

(Cyclopentadienyl)-(8-oksihinolina)zirconium dichloride (VI)

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and (cyclopentadienyl)-[8-(2-methyl-5,7-dichlorohydrin)oxy] zirconium dichloride (VII)

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get in the interaction lithium salts derived from 1.45 g (0.01 mol) of 8-oksikhinolinata or 1.15 g (0,005 mol) of 5,7-dichloro-2-methyl-8-chinoline respectively with equimolar quantities cyclopentadienylzirconium of trichloride in toluene at (-78)oC. After stirring overnight and filtering of the toluene solution of the isolated reaction products (of 0.62 g of compound of formula VI and 1.7 g of compound of formula (VII).

EXAMPLE 4

Polymerization

All the polymerization processes carried out in a reactor with a volume of 1.7 liters Before polymerization reactor is heated at 130oC and kept at this temperature in a stream of nitrogen for 30 minutes. Ethylene, hydrogen, hexene, butene and nitrogen is passed through a column containing a molecular sieve 13X. T is and add the required volume of diluted polymethylsiloxane (PMAO) of AKZO. The required amount of hydrogen fed into the reactor vessel stainless steel 1 liter, filled with hydrogen, by controlling the differential pressure (p). The catalyst solution in toluene is added to the reactor under nitrogen pressure. During the experiment, when the polymerization in the reactor to maintain isothermal conditions. The ethylene fed into the reactor and maintain the pressure at 1034,25 kPa using a reducer. After stabilization in the reactor pressure and temperature it serves a suspension of catalyst and start the polymerization process. The flow of ethylene was monitored using a flow meter of the brook.

The polymerization is stopped by pressure relief and polymer allocate using filtering. The polymer is stabilized by the addition of approximately 1000 parts per million of bottled hydroxytoluene/hexane (BHT), followed by curing at 80oC in a vacuum drying Cabinet. The melt index of the polymer is determined in accordance with ASTM D-1238. The density of the polymer is measured using samples obtained by direct pressing in the mold, on a column with a gradient of density in accordance with ASTM D-1505 85.

Reaction conditions are given in table 1.

The results of polymerization are shown in tab is alimera, obtained per gram of catalyst per hour. The melt index of the polymer (MI) is determined in accordance with ASTM D-1238, mode E mode f

The melt index (MI2 and MI20) determine when the load respectively of 2.16 kg (E) and under a load of 21.6 kg (F). MFR is the ratio of the melt index MI20 (F) to the melt index MI2 (E mode). The density of the polymer is determined in accordance with ASTM D-1505. Molecular weight distribution is determined by means of gel chromatography on a Waters chromatograph at 150C 135oC using as solvent 1,2,4-trichlorbenzene. Srednevekovoy molecular mass Mwand the ratio of Mwto Mndetermine the characteristics of the molecular mass distribution.

As follows from the data shown in the tables, the catalysts according to the invention have good performance and can achieve high molecular weight polymers, as evidenced by low values of melt index MI, and catalysts VI and VII does not lose its properties even at higher temperatures (110oC).

1. Catalytic system for polymerization of olefins, comprising socialization and catalyst, which contains a compound parentally ligand contains the remainder of xenolinux or pyridyloxy General formula

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or

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where Y represents O;

M means titanium, zirconium or hafnium;

each X is independently from each other halogen;

L means X, cyclopentadienyl or

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where each R' is independently from each other H, alkyl (C1-C6or halogen.

2. The catalytic system under item 1, characterized in that socialization selected from the group comprising methylalumoxane, polymethylsiloxane and an acidic Sol containing coordinational inert anion.

3. The catalytic system under item 1, characterized in that the transition metal 4 groups selected from the group comprising zirconium and titanium.

4. The catalytic system under item 1, wherein the bidentate ligand is selected from the group comprising substituted or unsubstituted residue 2 pyridyloxy and 8 xenolinux.

5. The catalytic system under item 1, characterized in that it further includes a carrier and is intended for use in the polymerization of olefins in the gas phase or in suspension phase.

6. The method of polymerization of ethylene, characterized in that the polymerization is carried out in the presence of a catalytic system under item 1.

7. The method of polymerization of one or Bo is practical system under item 1.

 

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