The ethylene polymer products
(57) Abstract:The invention relates to ethylene polymers, intended for the production of various molded products. The possibility of extruding at lower pressure in the mouthpiece and the consumption of electric current is due to the fact that the ethylene polymer has a new range of properties: index polydispersity at least approximately 3,0; melt index ER and the index of the spectrum of relaxation times of the PCT such that (RCI) (IL0,7) is greater than about 26; index distribution crystallizable chain length Lw/Lnless than about 3. The ethylene polymer has at least about 0.3 long chain branches per 1000 carbon atoms of the main chain and is obtained by polymerization of ethylene and higher alpha-olefin with a catalytic composition consisting of a metallocene catalyst and socializaton. 2 c. and 10 C.p. f-crystals, 2 ill., 3 table. The present invention relates to ethylene polymers differing improved processability, in particular, sprituality and a narrow distribution of co monomer, which can be mainly obtained by the method of low pressure. On the extrusion properties of the melt toshodai low-density polyethylene high pressure under the same melt index.Linear polyethylene can be easily obtained by means of low pressure, for example, in the gas phase, fluidized bed reactor. Its physical and mechanical properties such as hardness, tensile strength at break and elongation at break, are at a good level. However, its processing is difficult. Linear polyethylene is characterized by a tendency to the destruction of the extrusion flow, and it is characterized by the instability properties of the films associated with such problems as the great contraction and the resonance phenomenon when drawing the extrudate arising in the manufacture of roll films.Low-density polyethylene high pressure, which is highly branched, preferably linear low density polyethylene in those applications that require easy processing. Low-density polyethylene high pressure can be easily ekstradiroval, for example, in the film, while avoiding such things as the destruction of the extrusion flow, overheating, or resonance when drawing the extrudate. However, traditional methods for such resins is provided by the use of tubular reactors or autoclaves, which operate at extremely vysokochistoi in the work and management. In addition, due to the highly branched structure of low-density polyethylene high-pressure inferior physical and mechanical properties of linear low-density polyethylene.Some researchers in this field have tried to solve the problem of poor processability of linear polyethylene is injected into the linear polyethylene of long chain branching. U.S. patent N 5272236, 5380810 and 5278272 in the name of Lai et al. and PCT application WO 93/08221 "The Dow Chemical Company" describe "mostly linear olefin polymers having certain properties, contributing to improved processability, comprising from about 0.01 to 3 long chain branches per 1000 carbon atoms of the main chain and molecular weight distribution of about 1.5 to 2.5.Similarly, the PCT application N WO/9407930, "Exxon Chemical Patents Inc." refers to polymers containing less than 5 a long line branches per 100 carbon atoms of the main chain, where at least some branching have a molecular weight in excess of the critical molecular weight of the segments between the nodes in the polymer chain. WO 94/07930 argues that such polymers are characterized by improved processability in the melt state and improved physico-mechanical is, different narrow composition distribution and excellent indicator of the tension of the melt. The so-called velocity of the melt of these copolymers comprise from 0.001 to 50 g/10 min, measured at a temperature of 190oC and a load of 1.5 kg/cm2i.e. the same as the melt index.And, finally, a PCT application N WO 94/19381, "Idemitsu Kasan Co., Ltd" refers to the ethylene copolymer based on ethylene and the olefin containing 3-20 carbon atoms, its good technological properties and the ability to control various properties such as density, melting point and crystallinity. This copolymer is characterized by the fact that 1) the main polymer chain does not contain a Quaternary carbon atom, 2) the activation energy of melt flow (Ea) is 8-20 kcal/mol and 3) when the Huggins constant k of the copolymer compared to the same indicator of linear polyethylene, characterized by the same limiting viscosity as that of the copolymer, the viscosity measurement is carried out in decaline at 135oC, dependence has the following form: 1.12 < k1/k2 5 (where k1 is a constant Huggins copolymer and k2 is a constant Huggins linear polyethylene).Developed a new class etileno the technological properties of low density polyethylene high pressure under the same melt index. Such ethylene polymers have a unique set of properties not known for polyethylene resins known technical solutions.Summary of the invention
The technical solution of the present invention provides for obtaining ethylene polymer having an index of polydispersity not less than about 3.0; melt index, IL, and the index of the spectrum of relaxation, RCI, such that (RCI) (ILcomprise a value greater than about 26 when it is approximately equal to 0.7; and the index of distribution of crystallizable chain length Lw/Lnless than about 3. Such ethylene polymer effectively extruded, showing a lower pressure in the mouthpiece and power consumption compared to conventional low density polyethylene or a new industrial manufactured by the polyethylene obtained in the presence of metallocene. Such ethylene polymer, which can represent a homopolymer of ethylene or copolymer of ethylene, can be easily processed into various target products, such as films for General purposes, transparencies, shrink film, extrusion coating, insulating sheath of the wire and cable sheath and cross-linked insulation power cable is odawa insulation and sheath, using methods well known in the art.Brief description of drawings
In Fig. 1 presents the dependence (RCI) (ILfrom melt index (IR) for the ethylene polymers of this invention and various other polyethylenes.In Fig. 2 presents the dependence of the rate constant of crystallization (CSC) on the density of the ethylene polymers of this invention and various other polyethylenes.Detailed description of the invention
The ethylene polymers of this invention include ethylene homopolymers and copolymers of ethylene with a linear or branched higher alpha-olefins containing from 3 to about 20 carbon atoms with a density lying in the range from about 0.86 to about 0.95. Acceptable higher alpha-olefins include, for example, propylene, 1-butene, 1-penten, 1-hexene, 4-methyl-1-penten, 1-octene, and 3,5,5-trimethyl-1-hexene. With ethylene can be polymerized diene, especially unpaired diene. Acceptable unpaired diene represent a linear, branched or cyclic hydrocarbon diene containing from about 5 to about 20 carbon atoms. Particularly preferred diene include 1,5-exeggcute (EPA), ethylene-propylene-diene terpolymer (EPDM), etc. In the number of comonomers can also include aromatic compounds containing vinylic unsaturation, such as styrene and substituted styrene. Particularly preferred ethylene polymers include ethylene and about 1 to 40 wt.% one or more of the above comonomers.These ethylene polymers have indexes polydispersity without amendments on long-chain branching of not less than about 3.0, preferably not less than about 4.0, which suggests that such ethylene polymers have a molecular mass distribution, which are mostly quite wide. Index polydispersity polymer (SOPS) is defined as the ratio of mass-average molecular weight of the polymer to srednekamennogo molecular weight of the polymer (Mw/Mn). SOPS are not corrected for long-chain branching is determined using the method of classification pressure chromatography (SEC) on the chromatograph WATERS 150C GPC operating at 140oC with 1,2,4-trichlorobenzene at a flow rate of 1 ml/min Range of pore size nozzles chromatographic column provides the division MM in the range from 200 to 10000 Dalty) as the calibration standard used plastic standard NBS 1475 or 1496 National Institute of technology standards.The ethylene polymers of the present invention have unique rheological properties, which give the high polymer is melt strength, the ability to liquefaction under the action of shear stresses and a nice hood, providing, thus, extreme ease of processing. This improved the processability are typical both for ease of extrusion and conversion processes, such as film obtained by extrusion injection blow, pneumotropica, extrusion molding coatings and shells, wire and cable. In particular, the ethylene polymers of the present invention have melt indexes, IL, and indexes spectrum of relaxation, IMR, such that the ethylene polymer is observed ratio
(FSW) (IL) > about 26 when it is approximately equal to 0.7.Preferably
(FSW) (IL) > about 30, when it is approximately equal to 0.7.In the last above ratio IL represents the melt index of the polymer, expressed in grams per 10 minutes, determined according to method ASTM D-1238, condition E, at 190oC, and IMR is an index of the spectrum of relaxation of the polymer in dimensionless units.IMR etileno what about the response to the deformation by using a rheometer. As you know, based on the magnitude response of polymer mechanics and the geometry of the rheometer used, it is possible to determine the dependence of the modulus of relaxation G(t) or the dynamic modulus G() and G(a) from time t or frequency , respectively (see J. M. the dealy and K. F. Wissbrun, Melt Rheology and its Role in Plastics Processing, Van Nostrand Reinhold, 1990, p. 269-297). The mathematical relationship between dynamic modulus and dynamic modulus of elasticity is an integral equation of Fourier, but a specific set of data can also be calculated from the other parameters, using the well-known spectrum of relaxation times (see. S. H. Wasserman, J. Rheology, vol. 39, p. 601-625 (1995)). Using classical mechanical model, it is possible to calculate the discrete spectrum of relaxation, consisting of a number of relaxation transitions or "types", each with a characteristic intensity or "weight" and relaxation time. Using this range, the modules can be expressed as follows:
< / BR>< / BR>< / BR>where N is the number of transitions and giandirepresent the weight and time of each transition (see. J. D. Ferry, Viscoelastic Properties of Polymers, John Wiley and Sons, 1980, p. 224-263).The relaxation spectrum of the polymer can be determined with the help of a special program, such is the division of the transitions in the relaxation spectrum, it is possible to calculate the first and second moments of the distribution, similar to the Mnand Mw, the first and second moments of the molecular mass distribution, as follows:
< / BR>< / BR>IMR is defined as gII/gI.Because IMR depends on parameters such as molecular weight distribution of polymer molecular weight and long chain branching, it is a reliable measure of the processability of the polymer. The higher the value of the IMR, the better the processability of the polymer.In addition, the ethylene polymers of the present invention have an index of distribution of crystallizable chain length, Lw/Lnless than about 3, preferably less than about 2, suggesting that they have a narrow distribution of comonomers and, therefore, are characterized by significant compositional homogeneity. The index of distribution of crystallizable chain length is determined by the method lucynova fractionation with increasing temperature (EFPT), as described by Wild et al. J. Polymer Sci., Poly. Phys. Ed. vol. 20, p. 441 (1982). A diluted solution of the ethylene polymer in a solvent such as 1,2,4-trichlorobenzene, a concentration of 1-4 mg/ml, load at high temperature in the market, controlling so that the ethylene polymer is crystallized on the nozzle in order of increasing degree of branching (or reduce crystallochemistry) at lower temperature. Then the column is heated to approximately 140oC, by adjusting the heating rate at the level of 0.7oC/min at a constant flow rate of solvent through a column of 2 ml/min. as polymer elution fractions decreasing the value of the degree of branching (or increasing the degree of crystallinity) with increasing temperature. To control the concentration of the eluates use infrared detector concentration. From the temperature data APPT you can retrieve the value of the frequency of branching for the co monomer. Accordingly, the value of the lengths of the main circuit between nodes, expressed as Lwand Lncan be calculated as follows. Lwrepresents a mass-average molecular mass of the section of the circuit between nodes
LW=iwiLi< / BR>and Lnrepresents srednekamennogo molecular weight of segments of circuits between nodes
where Wi- mass fraction of the polymer components i have re co monomer ethylene polymers can be characterized using the method of differential scanning calorimetry (DSC). In the case of using the method of the DSC melting point is measured differential scanning calorimeter, such as DSC 2920, industrial supply company "Thermal Analysis Instruments, Inc. ". The polymer sample weight of approximately 5 mg, sealed in an aluminum pencil is first heated to 160oC at a rate of 10oC/min, and then cooled to -20oC with a rate of 10oC/min followed by a secondary heating to 160oC at a rate of 10oC/min peak melting temperature during the second endothermic melting is defined as the melting point of the polymer.Associated with DSK properties of the ethylene polymers of the present invention are preferably the following characteristics:
1) the index of homogeneity on DSK, DSK-GI, no less than about 7, preferably not less than about 9, and
2) the rate constant of crystallization, CSC, equal to or greater than 1.DSK-GI is determined as follows:
DSK-GI = [(Tmheterog. - Tm)/(Tm, heterogen. - Tm, homogen.)]10,
where Tmrepresents the peak melting temperature of the ethylene polymer, and Tmheterog. and Tm, homogen. represent the peak melting temperature of sooty same density, as the ethylene polymer of the present invention. The relationship between melting point and density, used for the heterogeneous and homogeneous polymers, the following:
homogeneous: Tm= -6023,5 + 12475,3 (density) - 6314,6 (density)2< / BR>heterogeneous: Tm= -49,6 + 189,1 (density)
Values KSK ethylene polymers of the present invention preferably equal to or greater than 1. CSC represents the relative velocity of crystallization in these conditions and is defined as follows:
CSC (g/cm3) = (density)(Tc/T1/2)
where Tcis the peak crystallization temperature of the polymer and T1/2- the temperature at which 50 wt.% crystallizable fractions of polymer secretaryshall. Both temperature, Tcand T1/2determine eksterne crystallization, obtained from DSC measurements of non-isothermal recrystallization processes. The density of the polymer was measured by the method ASTM D-1505.Another preferred characteristic of the ethylene polymers of the present invention is that they contain not less than about 0.3 long chain branches per 1000 carbon atoms of the main chain. This introduces an additional is retene contain not less than about 0.5 of long chain branches per 1000 carbon atoms of the main chain. More preferably, the ethylene polymers of the present invention contain at least about 0.7 of long chain branches per 1000 carbon atoms of the main chain. Long-chain branching, or DCR, measured by a combination of methods exclusion chromatography size (EHR) with mortar viscosimetry on the instrument Waters 150C GPC (Waters Corporation) with subsequent measurement on the differential viscometer production Viscotek Corporation" in the same experimental conditions, which are described in any literature on standard exclusion chromatography size. To obtain a calibration curve using polyethylene standard of known molecular mass distribution and the characteristic viscosity in 1,2,4-trichlorobenzene at 140oC, such as NBS 1475 or 1496. Values DCR calculated according to the ratio of the viscosity of the branched polymer to the viscosity of a linear polymer of the same molecular mass (cm. Mirabella F. M., Jr.; and Wild L., Polymer Characterization, Amer. Chem. Soc. Symp. Ser., 227, 1990, p. 23). Depending on the relationship of viscosity to the ratio of mean-square radius of gyration of the branched polymer to the linear polymer of the same molecular weight used is the Epsilon to 0.75 cm. Foster, G. N., McRury T. B., A. E. Hamielec , Liquid Chromatogr DCR by the equation of the Covenant í-Stockmayer (B. Zimm H. , W. H. Stockmayer, J. Chem. Phys., vol. 17, p. 1301, 1949), as described in the book "Developments in Polymer Characterization-4", J. V. Dawkins, ed., Applied Science, Barking, 1993.The ethylene polymers of the present invention can be obtained by any conventional method, suspension, solution, dispersion or gas-phase polymerization in the conditions of the reactions used in these processes. You can use a single reactor or several reactors. Preferred is a gas-phase polymerization using one or more fluidized bed reactor.Similarly, the catalytic compositions that can be used to produce ethylene polymers of the present invention, are any of the known compositions used for the polymerization of ethylene, such as for example, those that contain one or more conventional catalysts of Ziegler-Natta and more new metallocene catalysts; catalysts both types are well described in the literature. To obtain ethylene polymers of the present invention can also be used and mixed catalyst system of numbers or among the known types of catalysts.However, the authors of the invention provides for the contact interaction in the conditions of the gas-phase polymerization of ethylene and optionally a higher alpha-olefin with a catalytic composition, contains
a) racemic and mesotheliomas colophony metallocene catalyst containing two cycloalkenyl ligands, United colophony communication and forming a complex with a metal atom, each cycloalkenyl ligand has an external chirality, and
b) socialization selected from the group comprising methylaluminoxane and modified methylaluminoxane.Preferred metal atom is the atom of titanium, zirconium or hafnium. Most preferred is zirconium atom.Each of cycloalkenyl ligands colophony metallocene catalyst has an external chirality. Chirality is used to describe asymmetric molecules or ligand, whose specular reflection is not subject to each other (i.e. do not have direction right or left). In acyclic molecules have a chiral center. In the following case, the chiral center is a carbon atom:
< / BR>In cyclic systems may be a plane of chirality, providing external chirality. To explain the concept of foreign chirality as an example we use the example indenolol ligands. Indenolol ligand can consider LCA 6 carbon atoms. Unsubstituted indenyl (i.e., cyclopentadienyls ligand containing only two Deputy, which form a ring of 6 carbon atoms) has no chirality. If chiral Deputy attached to indenolol the ligand, this ligand is described from the point of view of chirality chiral center Deputy. However, if indenolol the ligand is attached one or more achiral substituents and there is no mirror plane of symmetry, it is considered that replaced angenlina ligand (cyclopentadienyls ligand containing two Deputy connected with the formation of 6-membered rings, plus one or more additional achiral substituents) has an external chirality
< / BR>Thus, the above 2-methylindoline ligand has no chirality (external or otherwise), and 1-methylindoline ligand has an external procurelnent.The term external chirality provides for the existence of a plane of chirality, which includes indenolol ligand. The metal (M) can form coordination with one or two chiral surfaces 1-methylindenyl ligands, forming the basis for the recognition of two properally surfaces. It
< / BR>
< / BR>where the radicals from R1to R8are the same or different monovalent substituents selected from the following: alkyl, aryl, alkylaryl, arylalkyl, a hydrogen atom, halogen atom or hydrocarbonsoluble, and any of the two radicals R1- R8can connect with the formation of rings from 4 to 8 atoms, for example, if R1= R4, R2= R3and if R2= R3, R1= R4and if R5= R8, R6= R7and if R6= R7, R5= R8the symbol "=" means chemical and stereochemical equivalence;
the radical Q is a divalent Deputy selected from alkylidene, dialkylanilines, dialkylamino and cycloalkylation;
M represents a transition metal atom of the GRU who or different and represent a monovalent ligands, choose from among alkyl, aryl, alkylaryl, arylalkyl, hydrogen atom, halogen atom, hydrocarbostyril, aryloxy, dialkylamino, carboxylate, tyaletnoi and diarylamino.The following compounds are explanatory but are not restrictive of the scope of claims of the present invention, examples of acceptable colophony metallocene catalysts containing two cycloalkenyl ligands with external chirality:
dichloride dimethylsilicone/2-mexed chloride dimethylsilicone/2-methylindenyl/Zirconia,
atoxic chloride dimethylsilicone/2-methylindenyl/Zirconia,
dichloride dimethylsilicone/2-methyl-4-tert.butylcyclopentadienyl/Zirconia, and
dichloride ethylenebis/2,4-dimethylcyclopentane/Zirconia.Preferably colophony metallocene catalyst is a dichloride of dimethylsilicone/2-methylindenyl/Zirconia, which describes the last of the above formula, where each of the radicals R1and R5represents methyl; each of the radicals R2and R6represents a hydrogen atom; the radicals R3and R4connected with the formation of-CH=CH-CH=CH-; the radicals R7and R8connected with the formation of-CH=CH-CH=CH-; radical Q is dimethylsilane; M is a zirconium atom; and each ATOR can be prepared by one of several methods. Method of obtaining is not determinative (for example, see A. Razavi, J. Ferrara, J. were obtained, Chem., 435, 299 (1992) and K. P. Reddy, J. L. Petersen, Organometallics, 8, 2107 (1988)).One such technique involves first the interaction of two equivalents optionally substituted cyclopentadiene with metallic deprotonation agent such as alkylate or potassium hydride, in an environment of an organic solvent, such as tetrahydrofuran, followed by interaction of this solution with a solution of one equivalent dehalogenating compounds, such as dichlorodimethylsilane. Then the resulting reaction ligand allocate using known methods (for example, by distillation or liquid chromatography), interact with two equivalents of metal-containing deprotonating agent specified above, and then interact with one equivalent of titanium tetrachloride, zirconium or hafnium, not necessarily forming coordination with the molecules of the donor ligands, such as tetrahydrofuran, in the environment of an organic solvent. The resulting colophony metallocene catalyst is extracted by known methods, such as recrystallization or the system of interaction of one equivalent of optionally substituted cyclopentadiene with one equivalent of a metal-containing deprotonating agent in the environment of an organic solvent, as described above, with subsequent interaction with one equivalent of the compound the molecule of which contains unsaturated five-membered ring that is attached ekzoticheskaya group, which may be nucleophilic attack, such as dealkylation. Then the reaction solution is mixed with water, and the ligand is extracted by known methods. Then interact one equivalent of a ligand with two equivalents of metal-containing deprotonating agent, as described above, and then the resulting solution is treated, in turn, one equivalent of titanium tetrachloride, zirconium or hafnium, not necessarily forming coordination with the molecules of the donor ligands, such as tetrahydrofuran, in the environment of an organic solvent. The resulting reaction colophony metallocene catalyst then remove by known methods.Acetalization is methylaluminoxane (MAO) or modified methylaluminoxane (MMAO). Iluminacin are known in this field connections and contain oligomeric linear alkylamines described by the formula
< / BR>and oligomeric cyclic alkylamines formula
***in the two above formulas represents methyl. For the modified methylaluminoxane the radical R***is a mixture of methyl and C2-C12alkyl groups, where methyl includes from about 20 to 80 wt.% R***groups.Iluminacin can be obtained in various ways. Usually a mixture of linear and cyclic iluminacao get in the preparation of alumination, for example, trimethylaluminum and water. For example, aluminiuim can be treated with water in the form of a solvent containing moisture. In another embodiment, aluminiuim, such as trimethylaluminum, can interact with a hydrated salt such as hydrated ferric sulfate. The latter method provides for processing dilute solution of trimethylaluminum, for example in toluene, the suspension of iron sulfate heptahydrate. It is also possible to obtain methylaluminoxane in the reaction tetralkylammonium containing C2or higher alkyl groups, such choicestotal by interaction trialkylaluminium connection or tetraalkylammonium, containing C2or higher alkyl groups with water to form polyalkylbenzene, which then interacts with trimethylaluminum. Further modified methylaluminoxane, which contain both methyl groups, and tertiary alkyl groups, can be obtained by reaction polyalkylbenzene containing C2or higher alkyl groups with trimethylaluminum and then with water, as described, for example, in U.S. patent N 5041584.The number of colophony metallocene catalyst and socializaton used in the catalytic composition may vary over a wide range. Preferably, the catalytic composition is contained in a quantity sufficient to provide not less than about 0,000001, preferably not less than approximately within 0.00001 wt.% transition metal per total weight of the ethylene or other monomers. The molar ratio of aluminum atoms contained in methylaluminoxane or modified methylaluminoxane, to metal atoms contained in colophony metallocene catalyst, is usually a value ranging from about 2:1 to 100,000:1, preferably in the range from about 10:1 to 10000:1, and most preferably in the range from about 30:1 pozicii on the media colophony metallocene catalyst or acetalization can be impregnated or deposited on the surface of inert carrier, such as silicon dioxide, aluminum oxide, magnesium dichloride, polystyrene, polyethylene, polypropylene or polycarbonate, so that the number of catalytic compositions ranged from 1 to 90 wt.% of the total weight of the catalytic composition and media.The polymerization is preferably carried out in the gas phase in the reactor with a fluidized bed, using known equipment and conditions. Preferably, the polymerization process carried out at elevated pressure lying in the range from 0.07 to 70 kg/cm2preferably from 3.5 to 28 kg/cm2and most preferably from 7 to 21 kg/cm2and temperatures in the range from 30 to 130oC, preferably from 65 to 110oC. Ethylene and other monomers, if used, interact with an effective amount of a catalytic composition at a temperature and pressure sufficient to initiate the polymerization reaction.Acceptable reaction system gas-phase polymerization include the reactor, in which you can enter the monomer(s) and a catalytic composition which contains a layer in which particles are formed of polyethylene. The amount of the claims of the present invention is not limited to any particular type of reacciona gaseous stream, containing one or more monomers continuously through a reactor with a fluidized bed within the specified reaction conditions and in the presence of a catalytic composition at a rate sufficient to maintain a layer of solid particles in a suspended condition. The gaseous stream containing unreacted gaseous monomer is continuously withdrawn from the reactor, is compressed, cooled and served on recycling to the reactor. The target product is removed from the reactor, and the remaining monomer is added to the recirculating stream.While this process can be used conventional additives provided that they do not impair the epimerization of racemic and mesotheleoma colophony metallocene catalyst.In the case where in the process as agent transfer circuit using hydrogen, the amount is from about 0.001 to about 10 moles of hydrogen per mole of total monomer raw material. In addition, to regulate the temperature in the system in the gas stream may be any gas inert to the catalytic composition and the reactants.To improve the catalytic activity can be used elapsedtime alkali aluminum, most preferably three-isobutylamine tri-n-hexyl aluminum. The use of such acceptors are well known.The ethylene polymers of the present invention can optionally be mixed with other polymers and resins using well known methods. In addition, if necessary, the ethylene polymers of the present invention can be used in mixtures with various additives and agents, such as stabilizers thermo - and photo-oxidation, including difficult phenolic antioxidants, employed amine light stabilizers and arylphosphine or phosphonites, vulcanizing agents, including dicumylperoxide, dyes, including carbon black and titanium dioxide, softeners, including metallic stearates, technological additives, including forecaster, additives reduce friction, including oleamide or erucamide, agents for preventing adhesion of the film to facilitate removal of products, including talc or silicon dioxide with a specific particle size, pore, the flame retardants and other traditional ingredients.The ethylene polymers of the present invention are used for the production of a number of articles, such as films, including transparent and those who power cable, molded articles obtained by molding under pressure, pneumaturia or rotational molding, extruded hoses, tubes, profiles, and sheet materials, insulation and semi-conducting membrane and/or sheet products. Methods of obtaining such products are well known.Examples
A number of the ethylene polymers of the present invention (examples 1-35) compared with samples of known polyethylenes according to various properties, including the index polydispersity SOPS, the index of distribution of crystallizable chain length (Lw/Ln), melt index (IL), the index of the spectrum of relaxation times (FSW) and (FSW) (IL), where it is approximately equal to 0.7. In addition, the comparison of indicators of long-chain branching DCR, index of homogeneity on DSK DSK-GI and a rate constant of crystallization (CSC).The ethylene polymers in examples 1-35 were obtained in gas-phase reactor with a fluidized bed with a nominal diameter of 35.6 cm and a height of layer 3.05. The catalytic composition used for obtaining the polymer in each of the examples included racemic and mesosoma dichloride dimethylsilicone/2-methylindenyl/Zirconia and methylaluminoxane socialization, NAS is finavia plastomer AFFINITY, industrial manufactured by The Dow Chemical Company", as specified in the table. 1.As comparative examples E-used linear ethylene polymers EXACT, industrial manufactured by Exxon Chemical as specified in table. 1.In comparative examples L-N used polyethylene obtained by the method of free radical polymerization under high pressure. These low density polyethylene were obtained in a tubular reactor high pressure in the presence of several organic initiators, pressure up to 3000 atmospheres and temperatures up to 320oC. To obtain these polyethylenes, low density, high pressure used in the manner analogous to that described Zabisky et al. Polymer, 33, No. 11, 2243, 1992.As comparative examples, O-p, used industrial linear low density polyethylene obtained by the method UNIPOL(Union Carbide Corp. ), using a gas-phase reactor with a fluidized bed. These polyethylene consisted of ethylene or copolymers of butene-1 or hexene-1, obtained in the presence of catalysts of the Ziegler-Natta, as described in U.S. patent N 4302565.As comparative examples R-T used polyethylene Nisko the use of catalysts of the Ziegler-Natta.Molecular weight, molecular weight distribution and long chain branching (DCR) were identified by means of exclusion chromatography size as follows. Used chromatograph WATERS 150C GPC, equipped with native speakers of mixed pore size for measurements of molecular weight and viscometer VISCOTEK 150R for consecutive measurements of viscosity. To conduct exclusion chromatography size (EHR) used pre-column with a length of 25 cm from Polymer Labs" with a nominal pore size of 50 , and then successively three columns with a length of 25 cm Shodex A-80m/S/Showa/ for separating linear ethylene polymer molecular mass from about 200 to 10000000 daltons. Speakers of both types contained porous nozzle poly/styrene-divinylbenzene/. For the preparation of polymer solutions and as a chromatographic eluent was used as the solvent is 1,2,4-trichlorobenzene. All measurements were carried out at a temperature of 140 0.2oC. Analog signals from the detectors mass and viscosity were entered in the computer system. Then all data were processed using standard software, industrial available from several sources (Waters Corporation and Viscotek Corporat the training method wide DFID (cm. W. W. Yau, J. J. Kirkland, D. D. Bly, Modern Size-Exclusion Liquid Chromatography, Wiley, 1979, p. 289-313). In the latter case, for calibration of the polymer must be known two associated with MM statistical quantities, such as srednekislye and bulk MM. Based MM calibration elution volume is transferred to the molecular weight of the investigated linear ethylene polymer.A detailed review of the methodology EHR-viscosity and equations used for converting data EHR and viscosity in the indicators of long-chain branching and molecular masses with the amendment presented in the article Mirabella and Wild above.DSC and TREF measurements were carried out as described above.Measurement of rheological properties held for dynamic oscillatory shear viscometer new model Weissenberg Rheogoniometer, industrial available from TA Instruments. The experiments were conducted in parallel plates under a nitrogen atmosphere at a temperature of 190oC. the Sizes of the samples were in the range from about 1100 to 1500 mm and had a diameter of 4 see the Experiments on frequency sweep covered the frequency range from 0.1 to 100 s-1when the amplitude of the deformation of 2%. Using the program rheometrical control TA Instruments off the each value of frequency. For each sample was calculated discrete spectrum of relaxation times by the values of the dynamic modules with industrial software package IRIS.
The results presented in table. 1 and table. 1 (part 2), indicate that only the ethylene polymers of the present invention are characterized by a unique combination of index polydispersity constituting not less than about 3.0, a melt index, IL, and the index of the spectrum of relaxation times, RCI, when the ratio (RCI) (IL) is greater than about 26 when equal to 0.7, and the index of distribution of crystallizable chain length, Lw/Ln, less than about 3. In Fig. 1 presents the dependence of the change (RCI) (IL) when equal to about 0.7, from the values of R & d in the table. 1.In addition, only the ethylene polymers of the present invention have values of CSC equal to or greater than 1. In Fig. 2 presents the dependence of the values of CSC from the density table. 1.Next, consider table. 2. The comparison of each of the ethylene polymers of examples 1-12 and comparative examples a, b, D, E, M, N, P and R on their sprituality in terms of obtaining film blowing machinery.The ethylene polymers of the present izobreteniya mixing auger for LAND (the ratio of length to diameter 30/1) at a speed of about 90 rpm and a given temperature of the mouthpiece 210oC. Granulated ethylene polymers of the present invention and the polyethylene of comparative examples were used to produce films by extrusion blow in normal process conditions. Equipment for extrusion film blowing machinery consisted of a Sterling extruder with a diameter of 1 and 1/2 inches, equipped with auger General purpose for LAND with L/D ratio 24:1 (constant pitch, decreasing the depth of the screw with a mixing head Maddox) and spiral finger tip.In table. 1A presents information on the use of mouthpieces, the extruding speed and temperature.In table. 2 presents the values of the pressure in the cylinder, and the amount of current required for extruding each of the tested resins, and the pressure in the cylinder, and the amount of current, normalized to the speed of the mouthpiece, so that you can make a direct comparison.Normalized data in the table. 2 indicate that the pressure in the cylinder, and the amount of current required for extruding ethylene polymers of the present invention, significantly less than those values required for extrusion of the polymers of the comparative examples is demonstrated excellent spunbond hood and ease of extrusion compared to low density polyethylene high pressure. 1. Ethylene polymer having an index of polydispersity at least approximately 3,0; melt index ER and the index of the spectrum of relaxation times RCI such that (RCI) (IL0,7) is greater than about 26; index distribution crystallizable chain length Lw/Lnless than about 3, having at least about 0.3 long chain branches per 1000 carbon atoms of the main chain, obtained by polymerization of ethylene and possibly higher alpha-olefin with a catalytic composition consisting of a metallocene catalyst and socializaton.2. The ethylene polymer under item 1, with the index of homogeneity by differential scanning calorimetry DSC-GI at least about 7.3. The ethylene polymer under item 1, with a rate constant of crystallization CSC equal to or greater than 1.4. The ethylene polymer according to p. 1 containing about 1 to 40 wt.% linear or branched alpha-olefin containing 3 to 20 carbon atoms.5. The ethylene polymer according to p. 1 containing about 1 to 40 wt.% the co monomer selected from propylene, 1-butene, 1-hexene, 4-methyl-1-pentene, 1-octene and mixtures thereof.6. The ethylene polymer according to p. 1 containing about 1 to 40 wt.% is Yes, and linear, branched or cyclic hydrocarbon dienes and mixtures thereof.7. The ethylene polymer under item 1, which is homopolymer.8. The molded article containing ethylene polymer under item 1.9. The moldings on p. 8, characterized in that it is a film, extrusion coating or molded article.10. The moldings on p. 8, characterized in that an insulated wire and cable and/or shell.11. The moldings on p. 8, characterized in that it is poperechnogo insulating sheath of the power cable.12. The moldings on p. 8, characterized in that it is the insulating sheath and/or semi-conducting sheath and/or plate.
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