Method for continuous gas-phase polymerization of ethylene and its mixtures withthe olefins and polymers
(57) Abstract:The invention relates to a method of gas-phase polymerization of ethylene and ethylene mixtures with olefins CH2=CHR in the presence of a highly active catalyst comprising a compound of titanium, containing at least one Ti-halogen bond, deposited on the magnesium dichloride in an active form, and the method includes the following stages: (a) the interaction of the catalytic component (b) prepolymerisation ethylene or ethylene mixtures with olefins to obtain the polymer in an amount of about 5 g per 1 g of solid component, is increased up to the number corresponding to about 10% of the final catalyst, (c) polymerization of ethylene or ethylene mixtures with olefins in the gas phase in the presence of system prepolymer catalyst, described in (b), while maintaining in the gas phase molar concentration of alkane between 20 and 90% relative to the total amount of gas. Also proposed that the polymers and copolymers obtained by using any of the methods described above. The invention enables to obtain polymers spherical shape having valuable morphological characteristics, and the possibility of gas-phase polymerization with high proizvoditelnosti polymerization of ethylene and ethylene mixtures with olefins of the formula CH2= CHR, in which R is alkyl, cycloalkyl or aryl radical with 1 to 12 carbon atoms, and named the polymerization is carried out in one or more fluidized bed reactor or mechanically mixed layer in the presence of a highly active catalyst comprising a compound of titanium, containing at least one Ti - halogen bond supported on dihalogenide magnesium in the active form.It is known that the continuous polymerization of one or more olefins, such as ethylene or propylene, is carried out in the gas phase in the reactor with a fluidized or mechanically mixed layer in the presence of a catalyst, based on the compound of a transition metal belonging to groups IV, V or VI of the Periodic table of elements, particularly in the presence of a catalyst of Ziegler-Natta or a catalyst based on chromium oxide.The polymer particles are supported in moving and/or peremeshivajutsa condition in a gaseous reaction mixture containing olefins. The catalyst was fed into the reactor, or continuously, or periodically, while the polymer contained in the fluidized or mechanically mixed layer, is removed from the reactor is also continuous is ESU, which is passed through the heat transfer device to implement recycling in the reactor. In addition, you can enter in a gas-phase reactor liquid flow to enhance heat transfer.During the flow of a gas-phase polymerization of olefin in the presence of catalysts of high activity, such as catalysts, containing the reaction product of Al-alkyl with a compound of titanium on a substrate of magnesium dichloride, the problem of heat removal is exacerbated by low thermal exchange gas phase.It was observed that small changes in the polymerization process, resulting, for example, from small fluctuations in the quality of the catalyst or of the olefin used in the reaction, can lead to changes in behavior and catalytic activity of polymer particles and have a material adverse effect on the process of gas-phase polymerization. Indeed, these small variations can lead to an unexpected increase in the amount of heat released during the reaction, which cannot be quickly and effectively removed gaseous reaction mixture is passed through the layer. Hot spots can be generated in the layer, resulting in formation of agglomerates rasplavlennoe is glomeratum. However, if the reaction conditions are adjusted easily, as though there was a decrease in the temperature or pressure of the polymerization, or by reducing the feed rate of catalyst into the reactor, in order to eliminate the undesirable effects of unexpected superactivation, the number and size of these agglomerates can to some extent be reduced. During this period, however, it is impossible to avoid reducing the rate of polymer formation and degradation of the resulting polymer.Usually, to avoid such disadvantages of the basic conditions of polymerization is chosen with a safety margin so as not to create hot spots and agglomerates. For example, use catalysts with reduced activity. The use of such conditions, however, leads or reduce output, or the deterioration of the polymer.As an attempt to repair the above-described disadvantages in the EP-A-359444 offers an introduction into the reactor, polymerization inhibitors, such as inhibitors of polymerization, or catalytic poisons, which reduces the rate of polymerization of the olefin. However, the use of inhibitors adversely affect the quality and properties of the polymer the AET process productivity.In addition to the above-described deviations in gas-phase process mechanism generating electrostatic charges, making the catalyst and resin particles tend to stick to the walls of the reactor by the action of electrostatic forces. In the case of a sufficiently long residence time of the polymers in reactive conditions, excessive temperature may cause the particles to melt, resulting in the formation layers or a thin layer of molten agglomerates in the granulated product.There are many reasons for the formation of electrostatic charges, for example, education charges due to friction between materials of different kinds, limited static dispersion, introduction to process very small quantities of prostatic agents, excessive activity of the catalyst, etc.There is a strong correlation between pastoobrazna and the presence of excessive electrostatic charge (both negative and positive). This is proved by the fact that a sudden change in the level of electrostatic charges should immediately deviation of the temperature of the walls of the reactor. Named temperature deviation mean adhesion of particles, cunosti mixing and homogeneity, there may be a violation of the introduction of the catalyst, as well as the clogging of the discharging system of the product.In U.S. Patent 4532311 discusses previous work related to various ways in which electrostatic charges could be reduced or eliminated. Processes suitable for use in the fluidized bed, include (1) the use of additives to increase the conductivity of the particles, thus providing a path for removal of the charge, (2) introduction to fluidized bed grounding devices, (3) ionization of gas or particles by electrical discharge for the formation of ions, which neutralize the electrostatic charge on said particles, and (4) the use of radioactive sources of radiation capable of producing ions, which can neutralize the electrostatic charges on the particles. However, the use of these devices in industrial scale reactors using a fluidized bed, is usually difficult and impractical.In U.S. Patent 4803251 describes a group of chemical additives that generate both positive and negative charges in the reactor, and which are introduced into the reactor in amounts of a few parts per millikelvin charges. Chemical additives include alcohols, oxygen, nitrogen oxides and ketones. In this case, too, a deterioration of the quality of the polymer, as well as a reduction of catalytic activity.The above-described deviation increases when the process gas-phase polymerization is carried out with the use of a highly active catalyst in order to obtain spherical polymers having tempting morphological characteristics (high volume weight, fluidity and mechanical strength). In this case, only when absolutely full control over the polymerization process it is possible to obtain polymer particles of the required characteristics. This is especially true when gas-phase method is used to obtain polymers of ethylene, where the high rate of polymerization exacerbates the problem.Known method of preparing a thermoplastic olefinic polymers , in which the polymerization is conducted in at least two reactors using a catalyst based on titanium halide on the substrate of the active MgCl2. Here reference is made to possible precontraction pre-obtained catalyst with a small amount of olefin in front of the main stage of polymerization, which is the process of gas-phase polymerization soft and reliable way overcoming or substantially reduce the above-described difficulties, without loss of productivity of the catalyst and/or degradation of the polymer.In particular, it was found that it is possible to obtain ethylene polymers with a high rate of education, expressed in grams of polymer per 1 g of solid component of catalyst for 1 h, and these polymers are obtained in the form of spherical particles with high flowability and high bulk density (particles under "spherical" I understand almost spheroidal or spherical particles).This invention, therefore, provides the possibility of obtaining polymers spherical shape having valuable morphological characteristics, in particular in connection with the use of super active catalysts with a particle size in the range of 30 to 150 μs. Such polymers spherical shape can be used without prior granulation, which, as you know, is an expensive operation from the point of view of energy consumption.Further, the possibility of process gas-phase polymerization with high specific capacity can significantly reduce the volume of the reactor.Another preimum any initiating dispersing layer, as usually done in gas-phase methods previously.The invention includes the following stages:
(a) interaction of the catalyst components in the absence of polymerizable olefin or (optional) in the presence of the aforementioned olefin in amounts not exceeding 20 g per 1 g of solid component of catalyst;
(b) prepolymerisation using the catalyst produced in stage (a), ethylene or mixtures thereof with olefins CH2= CHR, in which R is alkyl (C1-C12, cycloalkyl or aryl radical, and named the olefins present in quantities up to 20 mol.% relative to ethylene to form the polymer in amounts of between 30 and 1000 g per 1 g of the solid components of catalyst;
(C) gas-phase polymerization of ethylene or mixtures thereof with one or more-olefin in one or more reactor (reactors) with a fluidized bed or a mechanically mixed layer, in the presence of system prepolymer catalyst formed in (b), while through the reactor(s) circulates alkane having 3 to 5 carbon atoms in a molar concentration in the gas phase, 20 - 90% relative to the total amount of gases.Preliminary education katalysator described above, makes it possible for easy control of the process gas-phase polymerization, avoiding the usual difficulties of the processes known from the prior development of technology.Examples of the olefins with the formula CH2= CHR following: butene-1, penten-1, hexene-1, 4-methyl-pentan-1, octene-1.In stage (a) components that make up the catalyst, are introduced into contact with an inert liquid hydrocarbon solvent such as propane, n-hexane and n-pentane at a temperature below 60oC and preferably at temperatures between 0 and 30oC, for from 6 to 60 minutesThe catalyst used in the process in accordance with this invention includes the reaction product of the following components:
(A) a solid component that disables the connection of titanium containing at least one Ti-halogen bond supported on magnesium halide in active form. The solid component may also include electron-donor compound (internal donor), for example, when you want to retrieve the LLDPE with a particularly narrow molecular weight distribution (MBP);
(B) connection of alkyl-aluminum, in particular trialkylaluminium;
(C) is not required, for example when you want to get LLDPE with a particularly narrow Wriststrong in the solid component (A).The catalyst formed in stage (a), is entered or continuously, or periodically in stage (b).Stage (b) can be carried out in the liquid or gas phase, preferably in the liquid phase with the use of hydrocarbon solvents, such as n-hexane, n-heptane, cyclohexane or low-boiling alkanes, such as propane, butane /preserving liquid state under the conditions in (b)/.Prepolymerisation ethylene in stage (b) was carried out at temperature from -30 to +50oC, preferably between -10 and +30oC. the Amount of pre-formed polymer is between 30 and 1000 g of polymer per 1 g of solid component of catalyst and preferably between 100 and 400 g of polymer per 1 g of solid component of catalyst. The final yield of the catalyst can be determined by analysis of the residual catalyst, for example, from the content of titanium and/or magnesium, or from material balance.Stage (C) gas-phase polymerization is carried out in accordance with known techniques, in one or more reactors with a fluidized or mechanically peremestivsheesya layers. The process is conducted at a temperature below the sintering temperature of the polymer particles. Typically, the temperature is maintained is at 1.5 and 3 MPa. As previously noted, the gas phase present in the reactor contains an inert C3-C5alkane in an amount of from 20 to 90 mol.% in relation to the total gases. Named alkane selected from the group consisting of propane, butane, isobutane, n-pentane, isopentane, cyclopropane, CYCLOBUTANE. Preferably, alkanol is propane.Alkane is fed into the reactor either monomer or separately and recycle along with recycle gas, i.e., gas streams that do not react in the layer and are removed from the polymerization zone, preferably by passing through a zone of lower velocity above the layer where gone particles can fall back into the layer. The recirculated gas is then compressed and then passed through a heat exchanger before returning to the layer (see for example, U.S. patents 3298972 and 4518750 to describe gas-phase reactors and methods.In the process corresponding to this invention, alkanes effective to achieve the advantages as described above, while the use of an inert gas such as nitrogen, is inefficient. Indeed, the use of nitrogen does not prevent the formation of large aggregates ("pieces"), followed by the need to stop the operation.In the reactor mixing is achieved by maintaining recirculatory gases at high speeds in the direction of the layer and via layer is typically about 50 times higher than the rate of supply of fresh gas. Fresh gas is passed into a layer with a velocity equal to the velocity at which the polymer product is removed.To ensure fluidization recirculating gas and, where required, a portion of the fresh gas is returned into the reactor at a point below the layer. The gas distribution plate is located above the point of return, which guarantees the appropriate gas distribution and also supports a layer of resin, where the gas flow stops.Hydrogen can be used as the transfer agent of the circuit in order to control the molecular weight of the polymer.A typical simplified flow chart of the process shown in the drawing.The components of the catalyst and the solvent (item is as reactor 2, as indicated by arrow B. Propylene served in the circulation reactor in the direction of arrow E. the resulting system catalyst-prepolymer served in the gas-phase reactor 4, or, if you want the Department obtained solid material from the liquid components of the separating device 3, and thence to the gas-phase reactor 4, where in-line gas recycle monomer, hydrogen and propane are served by the arrow C. the Polymer leaves the reactor 4, after passing through the separator 5 into the reactor 6, where the monomer, hydrogen and propane are served by the arrow D. the Spherical polymer beads unloaded from the reactor 6 to the separator 7. If the process involves a single stage vapor-phase polymerization, the resulting polymer is collected in the outlet of the separating device 5.The solid components of catalyst used in the process of this invention include compounds of titanium with the formula Ti(OR1)nXy-nwhere 0 n (y-1), Y is the valence of titanium, X is halogen, preferably chlorine, R1- 1 - 12 C-alkyl, cycloalkyl or aryl radical, or COR-group deposited on a magnesium halide in active form. Of particular interest are compounds with the above basic formula in which y = 4; n can be between 1 halogenide, used as a substrate for catalysts of the Ziegler-Natta described in detail in the patent literature. U.S. patents 4298718 and 4495338 describe the first time the use of these substrates.Mg-dihalogenide forming substrate catalytic components used in this invention are characterized by the x-ray spectra in which the most intense line, which appears in the spectrum of non-activated halide, disappears, but instead appears a halo with the maximum intensity shifted towards smaller angles compared to the angle of the most intense line, or the line is still present, but is smeared.Preferably, the halide of magnesium was magnesium chloride.The titanium compounds suitable for the preparation of the solid catalytic components include Ti-halides, such as TiCl4that is most preferred, and trichloroacetate titanium, such as tricarboxylate and trichlorophenoxyacetic. In these cases, the connection titanium does not need to be restored with the use of reducing agents that can reduce the valence of titanium to values below 4.As examples of vosstanovlenie, policiticians.The connection of titanium can be obtained in situ, for example, the interaction of tetrachlorogallate titanium with a halogenation agent such as SiCl4, TiCl4galoisienne, AlCl3, Al-alkylhalogenide. In the latter case, as for aluminiuim halides, they are as halogenation, and regenerative activity, resulting in a compound of titanium, in particular, has a valency below 4.Examples of solid catalytic components that are useful when used in the process of this invention described in U.S. patent 4218339 and 4472520, the consideration of which, moreover, introduced by the link. Solid catalyst components can also be prepared in accordance with the methods described in U.S. patent 4748221 and 4803251.Especially preferred for this invention the catalytic components with regular morphology, for example spherical or spheroidal.Examples of such components are presented in the Italian patent applications M1-92A-000194 and M1-92-A-000195. When using such components can be obtained polymers with valuable morphological characteristics and a high value of bulk density.The amount of titanium, which is present on the substrate may be, for example, up to 20 wt.% in the calculation of metallic titanium and preferably amounts to between 1% and 16%.Suitable internal electrondonor include simple esters, amines, ketones and diesters of General formula
< / BR>where
R" and R"' are the same or different from each other and can be alkyl, cycloalkyl and aryl radicals with 1 to 18 carbon atoms, and RIVand RVthe same or different and are alkyl radicals with 1 to 4 carbon atoms.Examples of these compounds include di-n-butylphthalate, diisobutylphthalate, di-n-octylphthalate, 2-methyl-2-isopropyl-1,3 - dimethoxypropane, 2-methyl-2-isobutyl-1,3-dimethoxypropane, 2,2-Diisobutyl-1,3-dimethoxypropane, 2-isopropyl-2-isopentyl-1,3-dimethoxypropane.The internal donor is mainly present in a molar ratio of the magnesium to 1 : 2 and preferably in a ratio of between 1 : 8 and 1 : 12.Connection aluminiumgie used as socialization for the preparation of the catalyst in stage (a), preferably selected from compounds trialkylamine, such as Al-triethyl, Al-triisobutyl, Al-three the AlEt2Cl and Al2Et3Cl3you can also use. The ratio of Al/Ti in the catalyst formed in stage (a) is higher than 2 and usually has a value between 20 and 800.The external donor may be the same or different from electrondonor present as internal.When the internal donor is an ester or polycarboxylic acid, the external donor is preferably selected from silicon compounds with the formula R1R2Si(OR)2where R1and R2- alkyl, cycloalkyl or aryl radicals with 1 to 18 carbon atoms, such as methylcyclohexyl-dimethoxysilane, diphenylmethoxy silane and methyl-t-BUTYLPEROXY silane.As stated above, the proposed process is particularly suitable for producing ethylene polymers, in which a high rate of polymerization of ethylene requires careful control of gas-phase process in order to avoid difficulties common to previously developed gas-phase processes, in particular when the process is carried out with a high specific capacity.For example: high-density polyethylene (PAPV, density above 0,940 g/cm3that includes homopolymers of ethylene and copolymers of ethylene with alpha-oleanane polyethylene with very low and ultra low density (PAOP and PAOP) is the density below to 0.92 g/CC and below 0.88 g/CC), containing copolymers of ethylene with one or more olefin having 3 to 12 carbon atoms, with the content of units derived from ethylene, above 80 wt. %, elastomeric terpolymer ethylene, propylene and dienes, and elastomeric copolymers of ethylene and propylene with a content of units derived from ethylene of between 30 and 70 wt.%, can be obtained.Preparation of solid catalyst component.In an inert atmosphere 28.4 g MgCl2, a 49.5 g of anhydrous ethanol, 10 cm3ROL OB/30 vaseline oil and 100 cm3silicone oil with a viscosity of 350 cG were introduced into a reaction vessel equipped with a mixer. The temperature was raised to 120oC and maintained at this value until the dissolution of the MgCl2. The hot reaction mixture was then transferred to a 1.5 l vessel equipped with a Ultra Turrax T-45 N stirrer and containing 150 ml of vaseline oil and 150 ml of silicone oil. Temperature 120oC while stirring for 3 minutes at 2000 rpm/min Then the mixture was transferred into a 2 l vessel equipped with a stirrer and containing 1 l of anhydrous n-heptane cooled to 0oC, and stirred at a speed of 6 m/s for about 20 min, and the temperature was maintained 0oC.The resulting particles were washed with n-hexane of the particles with a residual alcohol content of 35 wt.%, 300 g of this product was uploaded to 5000 cm3reactor in suspension with 300 cm3anhydrous hexane. Under stirring at room temperature was slowly loaded 130 g of triethylaluminum (TEAL) in hexane solution. The reaction mixture was heated at 60oC for 60 min, then stirring was stopped, the reaction mixture was left to defend and separated the pure clear liquid above the precipitate. Processing BEAL was repeated twice under the same conditions, then the final solid product was washed with hexane and dried at 50oC. 260 g of the so-treated substrate was placed in the reactor together with 3 l of anhydrous hexane at room temperature under stirring filed 242 g of Ti(OB4)4. The reaction mixture was stirred 30 min and then 350 g SiCl4, washed with 250 ml of hexane, was added for 30 min at room temperature. The temperature was lowered to 65oC and continued to stir for another 3 hours, the liquid phase was then separated by settling and siteniravam. The solid product was washed 7 times with hexane, the remaining component was dried at 50oC under vacuum.Example 1. The experimental configuration shown in the drawing, was used to produce HDPE. A solid component, pradio activation and from there on stage suspension of prepolymerisation with ethylene. The liquid phase of the suspension was propane. Prepolymer containing propane suspension, continuously transferred from prepolymerisation apparatus in the first gas-phase reactor. In the apparatus of prepolymerisation also allow hydrogen to control the molecular weight of prepolymer. In the first and second gas-phase reactors missed propane for better control system activity.The basic conditions of the process
TemperatureoC - 10
The residence time in the reactor, min - 2,9
TEAL/Ti, mol. - 40
Temperature oC - 20
Prepolymerisation ratio, g cat./g propol - 1/300
The first gas-phase reactor
TemperatureoC - 85
Pressure, bar - 25
The ethylene mol.% - 16,7x< / BR>Hydrogen, mol.% - 12,3x< / BR>Propane, mol.% - 6,9x< / BR>1 stage polymerization, % - 32
the 2nd gas phase reactor
TemperatureoC - 85
Pressure, bar - 22
The ethylene mol.% - 27,2x< / BR>Hydrogen, mol.% - 20,2x< / BR>Propane, mol.% - 51,8x< / BR>Characteristics of the final product
The final polymer yield, kg PE/g TV. component of the catalyst - 11,3
True density, kg/l - 0,961
The index of the melt - 40,4
The diameter of > 1,000 - 55,8
The diameter of > 500 - 3,0
The diameter of < 500 - 0,8
Note:xThe balance of 100% is achieved because of other inert impurities (ethane, propane, butane, and so forth) present in the monomers fed to the polymerization.Example 2. The experimental configuration shown in the drawing, was used to produce LLDPE. A solid component prepared in accordance with the basic method, and the solution TEAL in n-hexane were introduced into a stage of activation and thence to the stage of suspension of prepolymerisation ethylene. The liquid phase of the suspension was propane. Prepolymer containing propane, the suspension is continuously removed from the unit prepolymerisation in the first gas-phase reactor. In Assembly prepolymerisation have also filed hydrogen to control the molecular weight of prepolymer. In the first and second gas-phase reactors allow propane to improve control system activity.Key terms:
Temperature oC - 2,8
The residence time in the reactor, min - 2,9
TEAL/Ti, mol. - 40
TemperatureoC - 30
Prepolymerisation ratio, g cat/g is proposed. - 1/250
1st gas is - , mol.% - 3,2x< / BR>Hydrogen, mol.% - 2,1x< / BR>Propane, mol.% - 85,0x< / BR>1st stage polymerization, % - 25
the 2nd gas phase reactor
TemperatureoC - 80
Pressure, bar 20
The ethylene mol.% - 33,3x< / BR>Butene-1, mol.% - 10,2x< / BR>Hydrogen, mol.% - 6,9x< / BR>Propane, mol.% - 47,6x< / BR>Characteristics of the final product:
The final polymer yield (kg PE/g TV. catalyt.K-TA) - 14,5
True density, kg/l - 0,918
The melt index "E", g/10 mn - 0,97
Apparent bulk density, kg/l - 0,364
Particle size, microns; wt.%:
The diameter of > 2,000 - 55,0
The diameter of > 1,000 - 43,4
The diameter of > 500 - 1,5
The diameter of < 500 - 0,1
Note:xThe balance of 100% is achieved because of other inert impurities (ethane, propane, butane, and so forth) present in the monomers fed to the polymerization.Example 3. In order to obtain the LLDPE used in the pilot plant configuration such as that shown in the drawing, but one-stage vapor-phase polymerization, and the resulting polymer was isolated after unloading from the reactor 4 to the separator 5. Stage preprocessing and prepolymerisation completely similar to that described in examples 1 and 2. In gas-phase reactor to relax is ivali
TemperatureoC - 16
The residence time, min 20
Prepolymerisation ratio, g cat/g may - 1//350
Stage vapor-phase polymerization
TemperatureoC - 80
Pressure, bar 20
The ethylene mol.% - 13,9x< / BR>Butene-1, mol.% - 4,8x< / BR>Hydrogen, mol.% - 2,4x< / BR>Propane, mol.% - 78,1x< / BR>Characteristics of the final product
The final polymer yield, kg PE/g TV. cat.comp.-TA - 11,0
True density, kg/l - 0,9197
The melt index "E", g/10 min was 1.04
Apparent bulk density, kg/l 0,35
Particle size, microns, wt.%:
The diameter of > 2000 to 31.2
The diameter of > 1,000 - 62,2
The diameter of > 500 - 5,3
The diameter of < 500 - 1,3
Note:xThe balance of 100% is achieved because of other inert impurities (ethane, propane, butane and so on) present the feed monomers. 1. Method for continuous gas-phase polymerization of ethylene and its mixtures with olefins CH2=CHR, where R is alkyl or cycloalkyl with 1 to 12 carbon atoms using a catalyst and pre-contact of the catalyst with the olefin, characterized in that conduct the interaction of the components of the catalyst of titanium compounds containing at least one link Ti - halog what utalization ethylene or mixtures of ethylene with one or more the olefin, with the formation of prepolymer containing up to 20 mol.% named-olefin, in amounts of between 30 and 1000 g/g of solid catalyst component, polymerization of ethylene or mixtures of ethylene with a-olefins CH2= CHR in the gas phase in one or more reactors with fluidized or mechanically mixed layer, using system prepolymer catalyst and circulating through the reactor alkane of 3 to 5 carbon atoms, and the molar concentration of the alkane is from 20 to 90% calculated on the total weight of the gas.2. Method for continuous gas-phase polymerization of ethylene and its mixtures with olefins CH2=CHR, where R is alkyl or cycloalkyl with 1 to 12 carbon atoms using a catalyst and pre-contact of the catalyst with the olefin, characterized in that conduct the interaction of the components of the catalyst of titanium compounds containing at least one link Ti - halogen deposited on the active dihalogenide magnesium, and connections alkylamine in the presence of polymerizing olefins in an amount of not more than 20 g per g of solid catalytic component compounds of titanium deposited on the active dihalogenide magnesium, prepolymerisation with the obtained catalyst is ethyl is wow-olefin, in amounts of between 30 and 1000 g/g of solid catalyst component, polymerization of ethylene or mixtures of ethylene with a-olefins CH2=CHR in the gas phase in one or more reactors with fluidized or mechanically mixed layer, using system prepolymer catalyst and circulating through the reactor alkane of 3 to 5 carbon atoms, and the molar concentration of the alkane is from 20 to 90% calculated on the total weight of the gas.3. The method according to p. 1 and 2, characterized in that the compound contains titanium, at least one link Ti-halogen and at least one link Ti-OR1and named the R1is alkyl, cycloalkyl or aryl radical having 1 to 12 carbon atoms or a COR group.4. The method according to p. 1 - 3, characterized in that the connection of titanium has an inner electrondonor.5. The method according to p. 4, characterized in that the catalyst is present in an external donor.6. The method according to any of paragraphs. 1 to 5, characterized in that the number of prepolymer is 100 - 400 g/g of solid catalytic component.7. The method according to any of paragraphs.1 - 6, characterized in that the polymerization is carried out in two reactors, the first of which produces 8. The method according to p. 1,2 or 3, characterized in that the olefin CH2=CHR selected from butane-1, pentene-1, hexene-1, 4-methylpentene-1,octene-1.9. The method according to p. 1,2 or 3, characterized in that the connection alkylamine is trialkylaluminium.10. The method according to p. 4, characterized in that the internal electrondonor selected from ethers, diesters, esters, amines, ketones.11. The method according to p. 10, characterized in that the internal electrondonor is an ester of an aromatic carboxylic acid.12. The method according to any of paragraphs.1 -11, wherein the alkane is propane.13. The method according to p. 1,2 or 3, characterized in that the catalyst is a compound of titanium and has a spherical shape.14. The polymers and copolymers obtained by using any of the methods, the relevant paragraphs.1 - 13.15. The polymers and copolymers according to p. 14, obtained by using any of the methods, the relevant paragraphs.1 to 5, and the polymers are ethylene.16. The polymers and copolymers according to p. 14 having a spherical shape and is obtained by using a method corresponding to paragraph 13, and the polymers are ethylene.17. The polymers and copolymers according to p. 14, obtained using the
FIELD: chemical industry, in particular two-component heterogeneous immobilized catalyst for ethylene polymerization.
SUBSTANCE: claimed catalyst includes alumina, mixture of transition metal complexes with nitrogen skeleton ligands (e.g., iron chloride bis-(imino)pyridil complex and nickel bromide bis-(imino)acetonaphthyl complex). According the first embodiment catalyst is prepared by application of homogeneous mixture of transition metal complexes onto substrate. iron chloride bis-(imino)pyridil complex and nickel bromide bis-(imino)acetonaphthyl complex (or vise versa) are alternately applied onto substrate. According the third embodiment catalyst is obtained by mixing of complexes individually applied onto substrate. Method for polyethylene producing by using catalyst of present invention also is disclosed.
EFFECT: catalyst for producing polyethylene with various molecular weights, including short chain branches, from single ethylene as starting material.
7 cl, 5 tbl, 27 ex
FIELD: olefin polymerization.
SUBSTANCE: invention relates to method for introducing of several catalysts in gas-phase or suspension reactor. Claimed method includes integration before introducing into single reactor of (a) solution, suspension or emulsion containing the first catalytic substance; and (b) solution, suspension or emulsion containing the second catalytic substance and optionally activator; followed by (c) introducing of (a) and (b) composition into single reactor in presence of hydrogen and one or more olefins wherein one polyolefin composition is formed.
EFFECT: polymers with wide bimodal molecular mass distribution.
14 cl, 3 ex
FIELD: polymerization catalysts and polymerization processes.
SUBSTANCE: high-activity ethylene (co)polymerization-appropriate supported titanium-based catalyst is composed of (A) supported catalytic component, notably titanium-containing active component on porous silica, containing at least one titanium compound, at least one magnesium compound, at least one alkylaluminum compound, at least one halide promoter, at least one electron-donor compound, and inert porous silica carrier, wherein halide promoter belongs to the class of compounds described by general formula F-R1[R2 bX(3-b)], in which F represents oxygen-containing functional group reactive to organoaluminum compound, titanium compound, and hydroxyl groups; R1 bivalent C1-C6-aliphatic or aromatic grouplinked to functional group F; R2 hydrogen atom, unsubstituted or halogen-substituted C1-C6-alkyl, halogen-substituted C3-C6-cycloalkyl, or halogen-substituted C6-C10-aryl; b=0,1 or 2; and X represents fluorine, chlorine, or bromine atom; and (B) alkylaluminum cocatalyst. Invention also discloses catalyst preparation method and ethylene (co)polymerization process in presence of above-defined catalyst.
EFFECT: enabled preparation of catalyst with good morphology and flowability of particles, high catalytic activity, good sensitivity to addition of hydrogen, and ability to include comonomer; improved particle morphology of polymers.
15 cl, 2 tbl, 11 ex
FIELD: chemical industry; methods of production of polyethylene in the tubular reactors with curing chambers or without them.
SUBSTANCE: the invention is pertaining to the method of production of polyethylene in the tubular reactors with the curing chambers or without them. The method provides, that the chain-radical initiator with cold ethylene or without it is fed into the flowing liquid medium containing ethylene with a comonomer. Conduct swirling of two being mixed streams at an angle or by means of the provided swirling component - in the cross section of the stream. In the zone of the area of introduction of the chain-radical initiator there is a narrowing of the cross-section, in which through a eccentrically located optimized outlet hole of the finger-shaped feeding component in the swirled stream introduce the chain-radical initiator.
EFFECT: the invention ensures a reliable introduction of the initiator in the tubular reactors with curing chambers or without them.
20 cl, 9 dwg
FIELD: polymerization processes.
SUBSTANCE: invention provides ethylene polymerization process at pressure between 1000 and 4000 bar and temperature from 140 to 320°C, which is characterized by that water is continuously or stepwise is fed into reactor so that reaction proceeds at such pressure and temperature, at which water is in supercritical state.
EFFECT: improved heat extraction and thereby increased degree of ethylene conversion.
9 cl, 2 tbl, 7 ex
FIELD: chemical technology, catalysts.
SUBSTANCE: invention relates to a nickel-containing catalyst and to a method for the oligomerization reaction of ethylene to a mixture of olefin products with high degree of linearity. Invention describes a composition of catalyst comprising product prepared by interaction of the following components in a polar organic solvent in the presence of ethylene: (a) bivalent nickel simple salt with solubility at least 0.001 mole per liter in indicated polar organic solvent; (b) boron hydride-base reducing agent; (c) water-soluble base; (d) ligand chosen from o-dihydrocarbylphosphinobenzoic acids and their alkaline metal salts; (e) trivalent phosphite wherein the molar ratio of ligand to phosphite is in limits from about 50:1 to about 1000:1. Also, invention describes a method for preparing the catalyst composition and a method for synthesis of a mixture of olefin products showing the high degree of linearity. Invention provides preparing the economically effective catalyst useful in synthesis of olefin substances showing the high degree of linearity.
EFFECT: improved and valuable properties of catalyst.
10 cl, 2 tbl, 3 ex
FIELD: polymer production.
SUBSTANCE: invention relates to polyolefin production technology, notably to synthesis of ethylene copolymers on modified chromium oxide catalyst under low pressure conditions is gas-phase fluidized-bed reactor. More particularly, low-pressure polyethylene production via continuous gas-phase ethylene/α-olefin copolymerization process is disclosed, said process being carried out in a reactor with fluidizing grate using catalyst containing chromium oxide, modifying oxide, fluorine, and silica as carrier. Reaction mixture composed of ethylene, α-olefin, hydrogen, and nitrogen and compositionally adjusted when being circulated by adding appropriate amounts of indicated constituents, provided that nitrogen content lies allays within a range of 30-50% based on the total volume of reaction mixture, is fed into reactor below fluidizing grate. Additional amounts of nitrogen are continuously introduced into reactor as a separate stream above fluidizing grate at the catalyst supply level. Chromium oxide contained in catalyst is chromium reduction product with chromium in the form of Cr2+ and modifying oxide is aluminum oxide prepared from alkoxyalumoxane. Silica carrier is modified with fluorine in the preliminary drying step.
EFFECT: increased yield of polyethylene based on unit mass of catalyst and reduced consumption of catalyst without loss in product quality.
1 dg, 3 tbl, 10 ex
FIELD: polymer production.
SUBSTANCE: invention relates to a gas-phase process for producing polyethylene from ethylene in fluidized-bed reactor, which process comprises: (i) hydrogenation stage, wherein supplied ethylene including impurities or secondary components such as acetylene and ethane reacts with hydrogen to remove acetylene via catalytic hydrogenation and to form ethylene, while a part of ethylene is converted into ethane; and (ii) polymerization stage, hen ethylene leaving stage (i) reacts in gas phase in fluidized-bed reactor to form polyethylene, wherein fluidizing gas contains, at the entry of reactor, ethylene and ethane in amount 20 to 70% based on the total volume of fluidizing gas, optionally with other components.
EFFECT: reduced investment and energetic expenses and increased yield of product for one pass in unit time.
5 cl, 2 dwg, 1 tbl, 3 ex
FIELD: polymer production.
SUBSTANCE: invention provides compositions for manufacturing air-permeable films showing elevated mechanical strength and microporosity. Bimodal polyethylene composition comprises: low-molecular weight ethylene homopolymer or copolymer of ethylene with one or more C4-C10-α-olefins, particulate filler (calcium carbonate), optionally olefin-based polymer (propylene/ethylene copolymer, polypropylene). Composition is characterized by melt flow rate 0.1 to 4.0 g/10 min and density 918 to 935 kg/m3. Films show very high water steam permeation velocity exceeding 3000 g/m3/24 h. Composition can be processed into thin films with low surface density: 25 g/m2 or below.
EFFECT: expanded technological possibilities and choice of air-permeable films.
20 cl, 2 tbl, 10 ex
FIELD: polymer production.
SUBSTANCE: invention relates to a process for production of polyethylene with narrow molecular mass distribution (Mw/Mn=3.8-5.4) allowing production of polyethylenes with variable molecular mass. Invention, in particular, provides a process wherein polyethylene obtained is characterized by elevated melt index (MI(5)=9-100) and which process is carried out under suspension conditions at 70-100°C in hydrocarbon solvent medium in presence of supported catalyst. The latter comprises titanium compound on magnesium-containing support, which is prepared via interaction of solution of a organomagnesium compound of general formula Mg(C6H5)2*nMg*Cl2*mR2O, wherein n=0.37-0.7, m=2, R2O is ether with R = i-C5H11 and n=n-C4H9, with a silicon compound. This silicon compound is prepared by reaction of silane compound R1 kSiCl4-k with silicon tetraethoxide Si(OR)4, where R1 represents alkyl or phenyl and k=0 or 1, at molar ratio R1 kSiCl4-k/Si(OR)4 =2-4 and temperature 15-60°C. Si/Mg ratio ranges from 1 to 2-5.
EFFECT: increased yield of polyethylene with high melt index and narrow molecular mass distribution at reduced hydrogen concentration in reaction medium.
1 tbl, 14 ex