A method of producing copolymers of ethylene with olefins, with an increased ability to process and composition based copolymer linear low density polyethylene and propylene in the form of particles

 

(57) Abstract:

The method of obtaining LLDPE with an enhanced ability to recycle by gas-phase polymerization is performed in two or more reactors, in which (any order) in one of the reactors will polimerizuet mixture of ethylene and alpha-olefin CH2= CHR, where R is alkyl having 1-10 carbon atoms, resulting in the copolymer containing up to about 20 mol.% alpha-olefin, and in the other reactor will polimerizuet a mixture of propylene and alpha-olefin CH2=CHR, where R is an alkyl radical having 2-10 carbon atoms, resulting in the copolymer containing 5 to 40 wt.% the above-mentioned olefin, in the amount of 5-30% by weight of the total polymer, and the system polymer - catalyst obtained in the first reactor, served in the other reactors. The method of obtaining the above-mentioned compounds is simple, allows you to use the same catalyst in both reactors, provides high performance film production and lower energy consumption. Target products have a lower degree of crystallinity and a higher melt index. 2 C. and 8 C.p. f-crystals, 1 Il, 1 table.

The present invention relates to a method for linear polite the purpose of monomers in two or more reactors with a fluidized bed (fluidized) layer or mechanically mixed layer, in which (any order) in one of the reactors will polimerizuet mixture of ethylene and alpha-olefin CH2= CHR (R -- alkyl having 1-10 carbon atoms), resulting in the LLDPE, and in the other reactor will polimerizuet mixture of propylene and alpha-olefin CH2= CHR', where R' -- alkyl radical having 2-18 carbon atoms, and in both reactors use the same catalyst.

LLDPE has many uses, but is particularly appropriate to use it in the production of films, because films of LLDPE have improved mechanical and optical properties compared to films made of LDPE.

However, the production of the films of LLDPE is associated with some difficulties, mainly due to the fact that the polymer in the molten state is not a high melt strength, while its viscosity in the molten state is quite high.

In order to keep performance constant, you need to modify the film extruders, for example by increasing the gap or increasing the temperature of the extrusion head.

These changes cause difficulties in cooling sleeve film which is vented at the exit of the extruder, and prawn ostatnio heat by heat welding.

To eliminate the above disadvantages, it was proposed to use a mixture of LLDPE with semi-crystalline copolymer of propylene and alpha-olefin CH2= CHR', where R' is an alkyl radical having 2-10 carbon atoms, in particular I-butene (U.S. patent N 4871813).

The copolymer contains from 7 to 40% by weight alpha-olefin, is the enthalpy of fusion less than 75 j/g and is added in an amount of from 1 to 25% by mass.

A mixture of LLDPE with a copolymer prepared by mixing in the molten state components, pre-mixed in the solid state (powder or granules).

There is a mixture of components in the solid state and applying the mixture directly to the extruder for molding the finished product.

LLDPE receive the traditional methods of polymerization and the copolymer of propylene and alpha-olefin receive separately, using the catalysts for stereospecific polymerization, able to give a semi-crystalline copolymer having a heat of fusion less than 75 j/g

The preparation of the above mixtures requires two separate lines of polymerization to obtain two polymeric components and then stage mixing for smeshivayte energy.

It is now established that it is possible to obtain a mixture of LLDPE with a copolymer of propylene and alpha-olefin CH2= CHR', with an increased ability to process and capable of formation of films with good mechanical and optical properties directly in the polymerization using at least two series-connected reactor, and (any order) in one of the reactors synthesize LLDPE, and the other is a copolymer of propylene and alpha-olefin using the same catalyst in both reactors.

The advantage of using the same catalyst in different series-connected reactors is that, instead of two production lines, use one, and in that the polymer mixture increases each particle of the catalyst, resulting in receiving a composition in which the components are uniformly mixed in the solid state, so it is unnecessary stage tabletting, which is necessary when the components get, using separate processes.

Thus, the polymer can be directly filed in the film extruders, which provides high performance film production and ing and curing stage tabletting, have a lower degree of crystallinity and a higher melt index.

In addition, homogenization at the level of each particle, provided by the method in accordance with the present invention, has a beneficial effect on film properties.

The method in accordance with the present invention includes the following stages:

a) prior to the contacting of the catalyst components mainly in the absence of the polymerized olefins (olefin should not be present in such quantity that was formed more than approximately 1 g of polymer per gram of solid catalyst component) is carried out in such a way as to obtain stereospecific catalyst capable of giving on stage 2) polymerization of the copolymer having an insolubility in xylene at 25oC at least 80%;

b) preliminary polymerization using the catalyst obtained in stage a), propylene or mixtures thereof with ethylene and/or alpha-olefins CH2= CHR, where R is an alkyl radical having from 2 to 10 carbon atoms such as butene-1, hexene-1, 4-methyl-pentan-1, under conditions that provide a polymer having an insolubility in xylene at 25oC biserov in the gas phase, executed in two or more series-connected reactors, fluidized bed or a mechanically mixed layer, in which (any order):

c1) in one of the reactors will polimerizuet mixture of ethylene and alpha-olefin CH2= CHR, where R is an alkyl radical having from 1 to 10 carbon atoms, resulting in the copolymer of ethylene with alpha-olefin containing up to about 20 mol.% alpha-olefin,

c2) in another reactor after removal of unreacted monomers coming from the reactor c1) if c1, the first reactor), will polimerizuet a mixture of propylene and alpha-olefin CH2= CHR', where R' -- alkyl radical, having from 2 to 10 carbon atoms, receiving as a result, the copolymer containing from 5 to 40% by weight alpha-olefin, in the amount of 5-30% by weight of the total weight of the polymer obtained in stage c1) and c2), and in which system the prepolymer - catalyst, obtained in stage b, is fed into the reactor in stage c1), and the system polymer - catalyst obtained in stage c1), Paul in the reactor stage c2). In the case of use on stage c2) of the first reactor of unreacted monomers from stage c2), are removed before the feed to the reactor stage c1) of the system polymer-catalyst obtained in stage c2).

the first reactor, where the reactivity of the catalyst is higher, use a reaction gas containing alkane with 3-5 carbon atoms (preferably propane) at a concentration of from 20 to 90 mol. % of the total amount of gas.

The copolymer formed at stage c2, preferably contains 10-15% (by weight) of alpha-olefin and is 15-25% of the total mass of the polymer stages c1) and c2).

It was unexpectedly found that the prior receipt of a catalyst, prepolymerisation treatment with propylene and the presence of alkane in the gas phase in the above molar concentration allow you to adjust the polymerization in the gas phase, to avoid the usual disadvantages of the known methods, which are (flaws) are essential, as reduced heat transfer capacity of the gas phase and the formed electrostatic charges that determine the propensity of the catalyst and polymer particles stick to the walls of the reactor.

The catalyst used in the method according to the present invention, furthermore, provides the possibility of growing a mixture of polymers on each individual particle of the solid component of catalyst, resulting in a good homogenization of the mixture of polymers.

Koyna least one titanium-halogen bond, connection titanium, drawing on a magnesium halide in active form. A solid component also contains electron-donor compound (internal donor), when the catalyst is not enough of stereospecific to get on stage c2) copolymers of propylene with insolubility characteristics specified in c2). As you know, stereospecificity catalysts supported on dihalogenide magnesium increases when using the internal donor. Generally, the internal donor is always used in order to obtain catalysts capable of giving on stage c2) copolymers of propylene with an alpha olefin CH2= CHR', having an insolubility in xylene higher than 80%, preferably in the range of 85-94%.

2) an Alkyl compound of aluminum.

3) Optional electron-donor compound (external donor) is the same as in the solid component, referred to in paragraph 1, or of a different type.

The external donor is used to give the catalyst required high stereospecificity. But when used as internal donors certain diesters, such as those described in the application A-344755 on the European patent, stereospecificity of the catalyst is sufficiently high and the external donor is not required Stage b) can be carried out in the liquid or gas phase. Preferably stage b) is carried out in liquid phase using as a liquid environment itself propylene or a hydrocarbon solvent such as n-hexane, n-heptane, cyclohexane or having a low boiling point alkane, such as propane, butane, (alkane) is in a liquid state under the conditions used in stage b).

Preliminary polymerization of propylene at the stage b is carried out at a temperature in the range of 0oup to 80oC, preferably from 5 to 50oC.

Propylene or mixtures of propylene with ethylene and/or other alpha olefins such as butene-1, hexene-1, 4-methylpentyl-1) polimerizuet, receiving as a result, the polymers having an insolubility in xylene higher than 60%. The output of the prepolymer is in the range from about 1 g to about 1000 g of polymer per gram of solid component of catalyst, preferably from 5 g to 500 g of polymer per gram of solid catalyst component.

Stage b) can be performed continuously or intermittently. In the first case, use appropriate tools to remove unreacted propylene before submitting obtained in stage b) system the prepolymer-catalyst in the gas-phase reactor.

Gas-phase with the fluidized bed reactor or mechanically mixed layer.

The monomers are served in two reactors in such proportions that will produce a copolymer having the desired composition.

As indicated above, before feeding the reaction mixture from the first reactor to the second produces remove unreacted monomers.

The process is carried out at a temperature below the fusion temperature of the polymer. Usually the temperature is in the range between 50 and 120oC, and preferably between 60 and 100oC. the total pressure is in the range between 1.5 and 3 MPa.

As stated above, it is irrelevant whether polimerizuet do first with a mixture of ethylene with alpha-olefin to obtain a copolymer LLDPE or first polimerizuet a mixture of propylene with an alpha olefin CH2=CHR' to obtain the corresponding copolymer.

However, it is preferable to carry out the synthesis of a copolymer of propylene with an alpha olefin in a first reactor to obtain a polymer with better fluidity and greater volumetric (bulk) mass.

The copolymer of propylene with an alpha olefin characterized in that it has an enthalpy of fusion (measured by the method described in U.S. patent N 4871813) above 70 j/g, preferably in the range between 75 and 95 Railway/g, and the rate of stereoregularity (defined and usually being in the range between 85 and 94.

Unexpectedly and in contrast to the characteristics of the copolymers of propylene and alpha-olefin used in the prior art, it was found that the method in accordance with the present invention allows to obtain the LLDPE polymers having good ability to process, even if the crystallinity and stereoregularity used copolymer high.

As mentioned above, the gas phase in different reactors, preferably contains alkane C3-C5in a molar amount of from 20 to 90% of the total amount of gases. Examples of suitable alkanes are propane, butane, isobutane, n-pentane, isopentane, cyclopropane, CYCLOBUTANE. The preferred alkanol is propane.

Alkane fed to the first reactor with a mixture of the monomers or separately and recycle along with recycle gas, i.e., a part of gas, which does not regulate the layer and which is removed from the polymerization zone, preferably by moving it to the area above the layer where the velocity decreases and the captured particles in the gas can again fall into the layer.

Recycle gas is then compressed and passed through a heat exchanger where dissipate the heat of reaction before recirculating the gas back into the layer. With the unusual and unexpected, what alkanes provide a very good regulation of the gas-phase reaction, whereas the use of an inert gas, such as nitrogen, is ineffective. In fact, the use of nitrogen does not prevent the formation of large clusters ("lumps") polymer, which necessarily leads to a shutdown of the installation.

In accordance with a preferred concentration of the alkane in the first make higher than in the second (or next) reactor.

Usually circulate alkane through both reactor.

To ensure full fluidization recycle gas and, if preferred, a portion of the fresh gas is again introduced into the reactor at a point below the layer. Naturally regiment (lattice) installed above the point of return, allows for efficient distribution of gas and, in addition, acts as a support for the layer of the polymer after the cessation of gas flow.

As the transmitter of the kinetic chain to regulate the molecular weight of the polymer can be used hydrogen.

A typical simplified schematic of the process is shown in the accompanying Fig. 1. Position 1 indicates the apparatus, in which through the reactor prior to polymerization. Positions 4 and 6 indicated reactors gas-phase polymerization, and positions 3, 5 and 7 indicated separators for separation of solid particles and the fluid. The components of the catalyst and thinning substance (propane) served in the reactor 1 preliminary contact, as shown by arrows A. the Last stage prior to contacting the catalyst serves to outline the reactor 2, as shown by arrows B, and propylene served in the above-mentioned loop reactor, as shown by the arrow E. the System of the prepolymer-catalyst fed into the separator 3, and thence to the gas-phase reactor 4, where line recirculation gas serves, as shown by the arrow C, propylene, alpha-olefin CH2=CHR', hydrogen and propane. The polymer from the reactor 4, passing through the separator 5, is introduced into the reactor 6, which serves, as shown by the arrow D, the ethylene, alpha-olefin CH2=CHR, hydrogen and propane. The polymer in the form of spherical granules discharged from the reactor 6 to the separator 7.

Active dihalogenide magnesium, used as a carrier for the catalyst of the Ziegler-Natta, widely described in the patent literature. The use of such dihalogenide primarily described in U.S. patent N 4298718 and N 4495338.

Dihalogenide magnesium, which is a carrier for conectarme, in most bright (intense) diffraction line appearing in the spectrum of active halide, has a lower intensity (brightness) and substituted by halo, the maximum intensity of which is shifted towards lower angles with respect to the most intense line.

The most active forms of dihalogenide magnesium the most intense line does not, and instead it has a halo with the maximum intensity shifted as described above.

The titanium compounds suitable for producing solid component of the catalyst include titanium halides, such as TiCl4, which is preferred, and TiCl3and haloalcohols, such as trichlorophenoxyacetic and tricarboxylate.

The connection of titanium can be used in a mixture with compounds of other transition metals such as vanadium, zirconium and hafnium.

Suitable internal electrondonor include ethers, esters, amines, ketones and simple diesters of General formula

< / BR>
where

RIand RII(the same or different from each other) - alkyl, cycloalkyl and aryl radicals having from 1 to 18 carbon atoms, and RIIIand RIV(adimakal compounds are complex alkalemia, cycloalkyl and arrowie esters of polybasic carboxylic acids, such as phthalic and maleic acids, and simple diesters of the formula

< / BR>
where

R1and R11this corresponds to the above definition.

Examples of such compounds are di-n-butylphthalate, di-isobutylphthalate, di-n-octylphthalate, 2-methyl-2-isopropyl-1,3-dimethoxypropane, 2-methyl-2-isobutyl-1,3-dimethoxypropane, 2,2-Diisobutyl-1,3-dimethoxypropane and 2-isopropyl-2-isopentyl-1,3-dimethoxypropane.

The internal donor is usually present in molar ratios from 1:8 to 1: 14 for Mg. The connection of titanium, expressed as Ti, is present in amounts from 0.5 to 10% by mass.

The solid components of the catalyst can be prepared according to methods described in U.S. patent N 4748221 and N 4803251.

If stereoregularity obtained catalyst is insufficient for the purposes of the present invention, it can be easily modified in accordance with well-known technologies described above.

Using the catalyst prepared from the components described in the application EP-A-344755 in European patent can be obtained with high specific activities (usually from 10 to 100 kg/h to the grave, having a high bulk volume and fluidity.

The procedure used in the preparation of catalyst components in the examples, is the preferred variant of the method described in the application EP-A-344755, which is included in this description by reference.

In particular, in the above-identified application components of the catalyst obtained from spheroidizing adducts MgCl2NR'r OH (R' is an alkyl or cycloalkyl radical having 2 to 10 carbon atoms, n is a number from about 3.5 to about 2.5), which partially remove the alcohol by heating at increasing temperatures from about 50 to about 100oC.

In the above formula n is equal to about 3, and by heating n reduce to values of 2.5 to 1 or lower.

Spheroidizing and partially dealcoholizing (without alcohol) product is introduced into a chemical reaction with excess TiCl4at temperatures from about 80 to about 135oC, and excess TiCl4remove, for example, by hot filtration.

Processing by TiCl4usually repeated, and the solid substance from which removes unreacted TiCl4, then washed with an inert hydrocarbon, until disappear is selected, in particular, complex alilovic esters, phthalic acid, such as di-n-butylphthalate, diisobutylphthalate, di-n-octylphthalate, and simple diesters having the above formula.

Electron-donating compound may also be introduced into interaction with the adduct to the reaction with the compound of titanium.

The alkyl aluminum compounds used as socializaton, choose from trialkyl aluminum compounds, such as triethylaluminum, triisobutylaluminum, tri-n-butylamine, tri-n-octylamine. Can also be used a mixture trialkyl aluminum compounds with halides alkylamine or sesquichloride alkylamine, such as AlEt2Cl and Al2Et3Cl3.

The ratio of Al/Ti in the catalyst formed in stage a), is greater than 1 and typically is in the range between 20 and 800.

The external donor may be the same with electron-donor compound present as internal donor, or different from it.

The molar ratio of alkyl aluminum compounds to the external donor is typically in the range between 2 and 30.

When the internal donor is an ester mnogoosnovnykh selected from silicon compounds of the formula R1R2(OR)2or R1(OR)3where R1and R2- alkyl, cycloalkyl or aryl radicals having from 1 to 18 carbon atoms, and R is an alkyl radical having 1 to 6 carbon atoms. Examples of the said silanes are methylcyclohexylamine, diphenylmethoxy, methyl-tert-butyl-dimethoxysilane and triphenylmethyl.

As an external donor can be also used simple diesters of the above General formula.

The solubility in xylene propylene polymer obtained in stage b), and a copolymer of propylene with an alpha olefin determined by dissolving 2 g of polymer in 250 ml of xylene at 135oC and mixing system. After 20 min the solution is cooled to 25oC. After 30 min, filtered off the precipitated material, the solution is evaporated in a stream of nitrogen and the residue is dried at 80oC.

In this way calculate the percentage of polymer in xylene at room temperature and the percentage of insoluble polymer.

The following examples are given to better illustrate the present invention and shall not be construed as limiting the scope of the invention. Unless otherwise stated, all Danemark, prepare as follows.

28.4 g MgCl2, a 49.5 g of anhydrous ethanol, 10 ml of paraffin oil ROL OB/30 and 100 ml of silicone oil having a viscosity of 350 cSt, enter (in inert atmosphere) in a reactor equipped with a stirrer and heated to 120oC until dissolved MgCl2. Then the hot reaction mixture is transferred into a vessel with a capacity of 1500 ml equipped with a stirrer Ultra Turrax" T-45N and containing 150 ml of vaseline oil and 150 ml of silicone oil. The temperature of the support at the level of the 120oC while stirring for 3 min at 3000 Rev/min the Mixture was then discharged into a two-liter vessel equipped with a stirrer and containing 1,000 ml of anhydrous n-heptane cooled to 0oC. the Mixture is stirred at a speed of 6 m/s for about 20 min, maintaining the temperature at 0oC. the resulting particle capture by filtration, washed with 500 ml of n-hexane and gradually heat up, increasing the temperature from 50 to 100oC for a time sufficient to reduce the alcohol content from 3 mol to molar content specified in the examples.

Adduct (25 g), containing alcohol in quantities specified in the examples, is transferred into a reactor equipped with a stirrer and containing the when the temperature reaches 40oC add diisobutylphthalate in an amount such that the molar ratio of Mg to phthalate was equal to 8.

The reactor is then heated to 100oC for two hours, then the solid is separated by precipitation.

Hot liquid is removed by siphon. Add 500 ml of TiCl4and the mixture is heated to 120oC for one hour under stirring. The stop stirring, and separating the solid by precipitation. Through siphon remove the hot liquid. The solid is washed with portions of n-hexane at 60oC and then at room temperature.

Example 1.

Use a plant that operates continuously and contains the reactor, in which the mixed components of the catalyst to obtain a catalyst contour (kelleway) reactor receiving the catalyst obtained at the previous stage and supplied with liquid propylene and propane, and two reactor with a fluidized bed, connected in series with the first reactor provides reception of the prepolymer obtained in the previous phase, and the issuance of the polymer in the second reactor after removal of unreacted monomers.

The process is carried out, submitting the m adduct MgCl2with ethanol containing 35% (by weight) of alcohol, the solution of triethylaluminum (TEAL) in n-hexane and methylcyclohexanecarboxylic as electron-donor compound in an amount such that the ratio TEPL/silane was equal to 4 by weight, and the molar ratio TEAL/Ti was equal to 120, in the reactor prior contact supported at a constant temperature of 20oC. In the same reactor serves propane as inert environment. The residence time is about 8.8 minutes

The product discharged from the reactor, then served in the contour of the reactor prior to polymerization, supported at the 50oC. the residence Time in the contour of the reactor is about 80 minutes

The first reactor, receiving the prepolymer obtained in the previous phase operates at 60oC and at a pressure at which carry out the reaction, equal to 1.8 MPa.

The average residence time of the polymer formed in the reactor is approximately 80 minutes

Monomers for reaction gases fed to the reactor are as follows:

propylene and butene;

hydrogen as molecular weight regulator;

the propane.

The first reactor produces polymer in a system of separation of ha is Dios polymerization.

The basic process conditions

Preliminary contact

temperature (oC) - 20

the residence time (min) - 8,8

Preliminary polymerization

temperature (oC) - 50

the residence time (min) 80

The first reactor of the gas-phase polymerization

temperature (oC) - 60

pressure (MPa) - 1,8

the residence time (min) - 68

propylene (mol.%) - 4,8

butene-1 (mol.%) - 1,2

hydrogen (mol.%) - 0,6

propane (mol.%) - 89

% polymerization - 11

associated butene (wt.%) - 9,8

MIL (230oC) (g/10 min) - 21

The second reactor gas-phase polymerization

temperature (oC) - 90

pressure (MPa) - 1,75

the residence time (min) - 76

butene-1 (mol.%) - 8,6

ethylene (mol.%) - 34

hydrogen (mol.%) - 9,2

propane (mol.%) - 44

% polymerization - 89

associated butene (end) (wt.%) - 7

MIE (190oC, 2,16 kg) (final) (g/10 min) - 1,1

F/E (21,6 kg/1,16 kg) (final) - 35

density (final) (g/cm3) - 0,916

Example 2.

Use the same installation as in example 1.

The process is carried out, feeding the components of the catalyst in the reactor prior contact, supported PR is then served in a dual reactor prior to polymerization, where served well as a certain amount of liquid propylene and propane as inert environment).

The residence time in the reactor prior to polymerization is approximately 80 min, and the temperature of the 50oC.

The first reactor, receiving the prepolymer obtained in the previous phase operates at 60oC and at a pressure at which carry out the reaction, equal to 1.8 MPa.

In the reactor serves the following monomers to the reaction and gases:

ethylene,

hydrogen as molecular weight regulator;

the propane.

The basic process conditions

Preliminary contact

temperature (oC) - 0

the residence time (min) - 9,5

Preliminary polymerization

temperature (oC) - 60

the residence time (min) 80

The first reactor of the gas-phase polymerization

temperature (oC) - 60

pressure (MPa) - 1,8

the residence time (min) - 45

propylene (mol.%) - 15

butene-1 (mol.%) - 3,5

hydrogen (mol.%) - 0,5

propane (mol.%) - 80

% polymerization - 24

associated butene (wt.%) to 11.2

MIL (230oC) (g/10 min) of 6.1

The second reactor gas-phase polymerization

temperature (ohydrogen (mol.%) - 4,2

propane (mol.%) - 68

% polymerization - 76

associated butene (end) (wt.%) - 7,5

MIE (190oC, 2,16 kg) (final) (g/10 min) - 1,14

F/E (21,6/2,16 kg) (end) - 50

density (final) (g/cm3) - 0,915

Granulometric composition of the polymers obtained in examples 1 and 2, presented in the table.

1. A method of producing copolymers of ethylene with olefins having a high potential for recycling, by polymerization of ethylene with olefins CH2= CHR, where R is alkyl having 1 to 10 carbon atoms, in the presence of a catalyst containing product obtained by the interaction of alkyl aluminum compounds with a solid component containing a halide or haloalcohols titanium and possibly electron-donor compound supported on magnesium halide in active form, characterized in that it comprises the following stages:

a) prior to the contacting of the catalyst components, mainly, in the absence of the polymerized olefins with the formation of stereospecific catalyst capable of giving during the polymerization of a mixture of propylene and alpha-olefin at a stage C2) copolymer having an insolubility in xylene at 25oC at least 80%;

b) with ethylene and/or alpha-olefins CH2= CHR, where R is alkyl having 1 to 10 carbon atoms, under conditions that provide a polymer having an insolubility in xylene at 25oC above 60%, in an amount of from about 1 to about 1000 g per 1 g of solid component of catalyst;

c) polymerization of the monomers in the gas phase, executed in two or more series-connected reactors, fluidized bed or a mechanically mixed layer, in which (any order):

c1) in one reactor will polimerizuet mixture of ethylene and alpha-olefin CH2=CHR, where R is an alkyl radical having 1 to 10 carbon atoms, resulting in the copolymer of ethylene and said alpha-olefin containing up to about 20 mol. % alpha-olefin, and after removal of unreacted monomers, coming from the first reactor, c2) in the other reactor will polimerizuet a mixture of propylene and alpha-olefin CH2=CHR', where R'is an alkyl radical having 2 to 10 carbon atoms, resulting in the copolymer containing 5 to 40 wt.% alpha-olefin, in the amount of 5-30 wt.% from the total mass of the polymer obtained in stage c1) and c2), the system of the prepolymer-catalyst, obtained in stage b), is fed into the first reactor, and the polymer-catalyst obtained in the first reactor, serves the t 10-15 wt.% alpha-olefin and is 15-25% of the total weight of the polymer, obtained in stage c1) and C2).

3. The method according to PP. 1 and 2, characterized in that the copolymer obtained in stage c2) is a copolymer of propylene and butene having an insolubility in xylene at 25oC above 85%.

4. The method according to p. 1, characterized in that in stage c), first polimerizuet a mixture of propylene and alpha-olefin CH2=CHR' for stage c2), and then polymerized mixture of ethylene and alpha-olefin, designed for stage c1).

5. The method according to p. 1, characterized in that the catalyst receive the interactions between the alkyl compound of aluminum, electron-donating compound and a solid component.

6. The method according to p. 5, characterized in that the electron-donating compound is a silane of the formula R1R2Si(OR)2or R1Si(OR)3where, R1and R2(same or different) - alkyl, cycloalkyl or aryl radicals with 1-18 carbon atoms, and R is an alkyl radical with 1-6 carbon atoms.

7. The method according to p. 1, characterized in that in the gas phase using alkane having 3-5 carbon atoms, at a concentration of 20 to 90 mol.% of the total amount of gases.

8. The method according to p. 7, characterized in that alkanol is propane.

9. WITH THE
MgCl2n R OH,

where R' is an alkyl or cycloalkyl radical having 1-10 carbon atoms;

n is a number from about 3.5 to about 2.5, which produce partial removal of the alcohol to the values of n ranging from 2.5 to 0.5.

10. Composition based copolymer linear low density polyethylene and propylene in the form of particles containing a mixture of a linear copolymer of ethylene with an alpha olefin CH2=CHR, where R is an alkyl radical having 1-10 carbon atoms, containing up to 20 mol.% alpha-olefin, in the amount of 70-95 wt.% from the total mass of the mixture and a copolymer of propylene with an alpha olefin CH2=CHR', where R' is an alkyl radical having 2-10 carbon atoms, containing 5-30 wt.% alpha-olefin, in the amount of 5-30 wt.% from the total mass of the mixture, and the said copolymer has an insolubility in xylene of at least 80% and the enthalpy of fusion of more than 70 j/g

 

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The invention relates to a method of polymerization of ethylene, which allows to obtain polyethylene having a density of about 0,93 and less

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[R2bX(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

Air-permeable films // 2299219

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 R1kSiCl4-k with silicon tetraethoxide Si(OR)4, where R1 represents alkyl or phenyl and k=0 or 1, at molar ratio R1kSiCl4-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

FIELD: polymers.

SUBSTANCE: invention relates to propylene polymer-base compositions eliciting improved shock-resistance and excellent optical properties that can be used for making bottles and containers. The composition comprises from 70 to 90 wt.-% of statistic copolymer of propylene with ethylene including from 1 to 6 wt.-% of ethylene and having the content of xylene-insoluble fraction 93 wt.-%, not less, and from 10 to 30 wt.-% of copolymer of propylene with ethylene containing from 8 to 18 wt.-% of ethylene. The ratio (B)/C2B containing percent by mass (B) as measured for the total mass content of (A) and (B) to the mass percent content of ethylene (C2B) as measured for the total mass content (B) is 2.5 or less. Prepared compositions elicit optimal balance of such indices as transmittance, rigidity and shock-resistance being even at low temperatures.

EFFECT: improved and valuable properties of compositions.

7 cl, 1 tbl

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