Olefin polymerization catalyst components

Abstract

A catalyst component for olefin polymerization comprising an internal donor selected from Ti, Mg, and 1,3-diethers, wherein the solid catalyst component is characterized by having an average particle size D50 in the range of 55 to 80 μm and a surface area (SA) measured by the BET method, expressed by the formula SA×D50 / 100, of greater than 60, preferably greater than 80, more preferably greater than 100, and particularly greater than 110.

Description

[Technical Field]

[0001] The present disclosure relates to diether-based ZN catalyst components having particular physical properties for use in the polymerization of olefins, particularly gas phase polymerization. [Background technology]

[0002] The advantages of using gas phase polymerization reactors are well known in the art. This type of polymerization technology is capable of producing polymers with valuable properties at relatively low investment costs. Additionally, the use of diether-based catalysts is a known alternative to phthalate-based catalysts.

[0003] A known problem to be solved in gas-phase polymerization processes is the tendency for polymer agglomerates to form, which can accumulate in various locations, such as the polymerization reactor and gas circulation lines. The formation of polymer agglomerates in a polymerization reactor can have many side effects. For example, the agglomerates can interfere with the removal of the polymer from the polymerization reactor by clogging the polymer discharge valve. Furthermore, a decrease in fluidization efficiency can occur if the agglomerates fall and cover some of the reactor's internal parts. This can result in the formation of larger agglomerates, potentially leading to reactor shutdowns.

[0004] This problem is exacerbated by the presence of small catalyst particles, which may be less able to dissipate the heat of polymerization, but larger catalyst particles may produce poorly formed morphologies and therefore lower bulk densities.

[0005] Such problems can also occur in certain types of gas-phase reactors. For example, as described in EP-B1-102195, a reactor with two interconnected polymerization zones in which the polymer circulates continuously is used. One zone (the riser) is under high-velocity fluidization conditions, while the other zone (the downcomer) is densely packed with polymer particles flowing downward. Transition operations between the production of different polymer grades and / or the use of different catalysts present special situations that can lead to hydrodynamic disturbances and, in some cases, reactor fouling.

[0006] A common attempt to minimize these problems is to operate the plant under low-traffic conditions, but while this is not always successful in avoiding operational problems, it invariably reduces plant productivity.

[0007] Therefore, a need is felt for a catalyst that has broad applicability in gas phase polymerization and has the ability to reduce or minimize operational problems during transitional motion.

[0008] This problem has been solved by the catalyst components described herein, which have a particular combination of chemical and physical characteristics. Summary of the Invention

[0009] Therefore, the object of the present application is a catalyst component for the polymerization of olefins comprising Ti, Mg and an internal donor selected from 1,3-diethers, said solid catalyst component being characterized in that it has an average particle size D50 in the range of 55-80 μm and a surface area (SA) measured by the BET method, according to the formula SA×D50 / 100, greater than 60, preferably greater than 80, more preferably greater than 100, in particular greater than 110. DETAILED DESCRIPTION OF THE INVENTION

[0010] Preferably, the solid catalyst component has an average particle size D50 in the range of 55 to 75 μm, more preferably 55 to 70 μm, especially 58 to 70 μm.

[0011] Preferably, the catalyst component has a porosity (P) of 0.18 cm as measured by the BET method. 3 / g, preferably 0.19 cm 3 / g or more, more preferably 0.20 to 0.25 cm 3 / g range.

[0012] Preferably, the surface area (SA) is 180 to 400 m 2 / g, more preferably 200 to 350m 2 / g range.

[0013] In a preferred embodiment, the value of the formula SA×P is greater than 10, preferably greater than 20, more preferably greater than 25, especially greater than 40.

[0014] Preferably, all of the above characteristics refer to the solid catalyst component in its non-prepolymerized form.

[0015] The internal donor is preferably selected from 1,3-diethers of formula (I) [ka] (I) In the formula, R I and R II are the same or different and are hydrogen or straight or branched C-C alkyl groups which may also form one or more cyclic structures. 18 R is a hydrocarbon group, and may be equal or different from each other. III The group is hydrogen or C1-C 18 R are hydrocarbon groups, and may be equal or different from each other. IV The group R III has the same meaning as R I ~R IV Each of the groups may contain heteroatoms selected from halogen, N, O, S, and Si.

[0016] Preferably, RIV is an alkyl radical of 1 to 6 carbon atoms, more specifically, methyl, while R III The radical is preferably hydrogen. I is methyl, ethyl, propyl, or isopropyl, R II R can be ethyl, propyl, isopropyl, butyl, isobutyl, tert-butyl, isopentyl, 2-ethylhexyl, cyclopentyl, cyclohexyl, methylcyclohexyl, phenyl, or benzyl. I is hydrogen, R II R can be ethyl, butyl, sec-butyl, tert-butyl, 2-ethylhexyl, cyclohexylethyl, diphenylmethyl, p-chlorophenyl, 1-naphthyl, 1-decahydronaphthyl. I and R II may be the same and may be ethyl, propyl, isopropyl, butyl, isobutyl, tert-butyl, neopentyl, phenyl, benzyl, cyclohexyl, cyclopentyl.

[0017] Specific examples of ethers that can be advantageously used include 2-(2-ethylhexyl)-1,3-dimethoxypropane, 2-isopropyl-1,3-dimethoxypropane, 2-butyl-1,3-dimethoxypropane, 2-sec-butyl-1,3-dimethoxypropane, 2-cyclohexyl-1,3-dimethoxypropane, 2-phenyl-1,3-dimethoxypropane, 2-tert-butyl-1,3-dimethoxypropane, 2-cumyl-1,3-dimethoxypropane, 2-(2-phenylethyl)-1,3-dimethoxypropane, 2-(2-cyclohexylethyl)-1,3-dimethoxypropane, )-1,3-dimethoxypropane, 2-(p-chlorophenyl)-1,3-dimethoxypropane, 2-(diphenylmethyl)-1,3-dimethoxypropane, 2-(1-naphthyl)-1,3-dimethoxypropane, 2-(p-fluorophenyl)-1,3-dimethoxypropane, 2-(1-decahydronaphthyl)-1,3-dimethoxypropane, 2-(p-tert-butylphenyl)-1,3-dimethoxypropane, 2,2-dicyclohexyl-1,3-dimethoxypropane, 2,2-diethyl-1,3-dimethoxypropane, 2,2-dipropyl-1 ,3-dimethoxypropane, 2,2-dibutyl-1,3-dimethoxypropane, 2,2-diethyl-1,3-diethoxypropane, 2,2-dicyclopentyl-1,3-dimethoxypropane, 2,2-dipropyl-1,3-diethoxypropane, 2,2-dibutyl-1,3-diethoxypropane, 2-methyl-2-ethyl-1,3-dimethoxypropane, 2-methyl-2-propyl-1,3-dimethoxypropane, 2-methyl-2-benzyl-1,3-dimethoxypropane, 2-methyl-2-phenyl-1,3-dimethoxypropane, 2-methyl-2-cyclopentyl-1,3-dimethoxypropane Cyclohexyl-1,3-dimethoxypropane, 2-methyl-2-methylcyclohexyl-1,3-dimethoxypropane, 2,2-bis(p-chlorophenyl)-1,3-dimethoxypropane, 2,2-bis(2-phenylethyl)-1,3-dimethoxypropane, 2,2-bis(2-cyclohexylethyl)-1,3-dimethoxypropane, 2-methyl-2-isobutyl-1,3-dimethoxypropane, 2-methyl-2-(2-ethylhexyl)-1,3-dimethoxypropane, 2,2-bis(2-ethylhexyl)-1,3-dimethoxypropane, 2,2-bis(p-methylphenyl)-1,3-dimethoxypropane, 2-methyl-2-isopropyl-1,3-dimethoxypropane, 2,2-diisobutyl-1,3-dimethoxypropane, 2,2-diphenyl-1,3-dimethoxypropane, 2,2-dibenzyl-1,3-dimethoxypropane, 2-isopropyl-2-cyclopentyl-1,3-dimethoxypropane, 2,2-bis(cyclohexylmethyl)-1,3-dimethoxypropane, 2,2-diisobutyl-1,3-diethoxypropane, 2,2-diisobutyl-1,3-dibutoxypropane, 2 -isobutyl-2-isopropyl-1,3-dimethoxypropane, 2,2-di-sec-butyl-1,3-dimethoxypropane, 2,2-di-tert-butyl-1,3-dimethoxypropane, 2,2-dineopentyl-1,3-dimethoxypropane, 2-isopropyl-2-isopentyl-1,3-dimethoxypropane, 2-phenyl-2-benzyl-1,3-dimethoxypropane, 2-cyclohexyl-2-cyclohexylmethyl-1,3-dimethoxypropane, and 2-cyclohexyl-2-i-pentyl-1,3-dimethoxypropane.

[0018] Furthermore, 1,3-diethers of formula (II) are particularly preferred, [ka] (II) where the radical R IV has the same meaning as defined in formula (I), and the radical R III and R V are equal to or different from each other and are hydrogen; halogen, preferably Cl and F; linear or branched C-C 20 Alkyl radical; C3-C 20 Cycloalkyl, C6-C 20ア Reel, C7-C 20 Alkylaryl, and C7-C 20 an arylalkyl radical, R V Two or more of the radicals may be bonded to each other to form an R selected from the group consisting of halogens, preferably Cl and F. VIcapable of forming saturated or unsaturated fused ring structures, optionally substituted with radicals; straight or branched C1-C 20 Alkyl radical; C3-C 20 Cycloalkyl, C6-C 20 Aryl, C7-C 20 Alkaryl, and C7-C 20 aralkyl radicals, wherein the radical R V and R VI optionally contains one or more heteroatoms as substituents to carbon atoms or hydrogen atoms, or both Preferably, in the 1,3-diethers of formula (I) and (II), R III The radicals are all hydrogen, R IV The radicals are all methyl. In addition, two or more R V The radicals bond together to form R VI Particularly preferred are 1,3-diethers of formula (II) which form one or more fused ring structures, preferably benzene structures, optionally substituted with radicals. Particularly preferred are compounds of formula (III): [ka] (III) In the formula, R III and R IV The radicals have the same meaning as defined in formula (I), R VI The radicals may be equal or different and may be hydrogen; halogens, preferably Cl and F; linear or branched C-C 20 Alkyl radical; C3-C 20 Cycloalkyl, C6-C 20 Aryl, C7-C 20 Alkylaryl, and C7-C 20 An aralkyl radical, optionally containing one or more heteroatoms selected from the group consisting of N, O, S, P, Si, and halogens, particularly Cl and F, as substituents to carbon or hydrogen atoms, or both.

[0019] Specific examples of compounds encompassed by formulas (II) and (III) are as follows: 1,1-bis(methoxymethyl)-cyclopentadiene; 1,1-bis(methoxymethyl)-2,3,4,5-tetramethylcyclopentadiene; 1,1-bis(methoxymethyl)-2,3,4,5-tetraphenylcyclopentadiene; 1,1-bis(methoxymethyl)-2,3,4,5-tetrafluorocyclopentadiene; 1,1-bis(methoxymethyl)-3,4-dicyclopentylcyclopentadiene; 1,1-Bis(methoxymethyl)indene; 1,1-Bis(methoxymethyl)-2,3-dimethylindene; 1,1-bis(methoxymethyl)-4,5,6,7-tetrahydroindene; 1,1-bis(methoxymethyl)-2,3,6,7-tetrafluoroindene; 1,1-bis(methoxymethyl)-4,7-dimethylindene; 1,1-bis(methoxymethyl)-3,6-dimethylindene; 1,1-bis(methoxymethyl)-4-phenylindene; 1,1-bis(methoxymethyl)-4-phenyl-2-methylindene; 1,1-bis(methoxymethyl)-4-cyclohexylindene; 1,1-bis(methoxymethyl)-7-(3,3,3-trifluoropropyl)indene; 1,1-bis(methoxymethyl)-7-trimethylsilyl indene; 1,1-bis(methoxymethyl)-7-trifluoromethylindene; 1,1-bis(methoxymethyl)-4,7-dimethyl-4,5,6,7-tetrahydroindene; 1,1-bis(methoxymethyl)-7-methylindene; 1,1-bis(methoxymethyl)-7-cyclohexylindene; 1,1-bis(methoxymethyl)-7-isopropylindene; 1,1-bis(methoxymethyl)-7-cyclohexylindene; 1,1-bis(methoxymethyl)-7-tert-butylindene; 1,1-bis(methoxymethyl)-7-tert-butyl-2-methylindene; 1,1-bis(methoxymethyl)-7-phenylindene; 1,1-bis(methoxymethyl)-2-phenylindene; 1,1-bis(methoxymethyl)-1H-benzo[e]indene; 1,1-bis(methoxymethyl)-1H-2-methylbenzo[e]indene; 9,9-bis(methoxymethyl)fluorene; 9,9-bis(methoxymethyl)-2,3,6,7-tetramethylfluorene; 9,9-bis(methoxymethyl)-2,3,4,5,6,7-hexafluorofluorene; 9,9-bis(methoxymethyl)-2,3-benzofluorene; 9,9-bis(methoxymethyl)-2,3,6,7-dibenzofluorene; 9,9-bis(methoxymethyl)-2,7-diisopropylfluorene; 9,9-bis(methoxymethyl)-1,8-dichlorofluorene; 9,9-bis(methoxymethyl)-2,7-dicyclopentylfluorene; 9,9-bis(methoxymethyl)-1,8-difluorofluorene; 9,9-bis(methoxymethyl)-1,2,3,4-tetrahydrofluorene; 9,9-bis(methoxymethyl)-1,2,3,4,5,6,7,8-octahydrofluorene; 9,9-bis(methoxymethyl)-4-tert-butylfluorene.

[0020] An additional electron donor different from the diether may also be present in trace amounts, if present, the additional donor is preferably selected from alcohols or monocarboxylic acid esters, the molar amount of which is preferably less than 25% of the amount of the 1,3-diether.

[0021] Preferably, the molar ratio of 1,3-diether to Ti atoms in the final solid catalyst component is in the range of 0.3:1 to 1.5:1, more preferably in the range of 0.4:1 to 1.3:1.

[0022] Preferably, the molar ratio of Mg atoms to 1,3-diether in the final solid catalyst component ranges from 4.0:1 to 25.0:1, more preferably from 5.0:1 to 20.2:1.

[0023] In a preferred embodiment, the molar ratio of Mg / Ti is in the range of 2-25, preferably 4-20, in particular 5-10.

[0024] The solid catalyst component contains, in addition to the electron donor described above, at least a titanium compound having a Ti-halogen bond and a magnesium halide. The magnesium halide is preferably MgCl2 in its activated form, which is widely known in the patent literature as a support for Ziegler-Natta catalysts. U.S. Patent Nos. 4,298,718 and 4,495,338 were the first to describe the use of these compounds in Ziegler-Natta catalysts. From these patents, it is known that activated magnesium dihalides used as supports or co-supports in catalyst components for olefin polymerization can be characterized by their X-ray spectra. In this X-ray spectrum, the intensity of the inactive halide decreases, and the maximum intensity is replaced by a halo that shifts to lower angles compared to the intensity of the more intense lines.

[0025] Preferred titanium compounds for use in the catalyst components of the present disclosure are TiCl4 and TiCl3, and further represented by the formula TTi(OR) n-y X yAlso usable are haloalcohol salts of the formula: where n is the valence of titanium, y is a number from 1 to n-1, X is a halogen, and R5 is a hydrocarbon group having 1 to 10 carbon atoms.

[0026] The preparation of the solid catalyst component can be carried out according to several methods. According to a preferred method, the solid catalyst component is prepared from a compound of the formula Ti(OR 5 ) m-y X y (wherein m is the valence of titanium and y is a number from 1 to m), preferably TiCl4, is reacted with a titanium compound of the formula MgCl2·pR 6 OH (wherein p is a number between 1.5 and 4.5, and R 6 It can be prepared by reacting magnesium chloride derived from an adduct of magnesium chloride with an alcohol (especially ethanol) containing 1.5 to 4.0 moles of alcohol per mole of magnesium.

[0027] The adduct can be prepared by contacting MgCl with an alcohol in the absence of an inert liquid dispersant, heating the system above the melting temperature of the MgCl-alcohol adduct, and maintaining the system to obtain a completely molten adduct. Specifically, the adduct is preferably maintained at or above its melting temperature under stirring for at least 1 hour, preferably 2 to 15 hours, more preferably 5 to 10 hours. The molten adduct is then emulsified in a liquid medium that is immiscible with and chemically inert to the molten adduct, and the adduct is finally quenched by contacting with an inert cooling liquid, which results in solidification of the adduct. Alternatively, the adduct may be left in the cooling liquid for 1 to 24 hours at a temperature ranging from -10 to 25°C before recovering the solid particles.

[0028] In a variation of this method, MgCl particles can be dispersed in a chemically inert liquid that is immiscible with the molten adduct. The system is heated to a temperature above the melting temperature of the MgCl·ethanol adduct, followed by the addition of the desired amount of alcohol in the vapor phase. The temperature is maintained at a value such that the adduct is completely melted for a period ranging from 10 minutes to 10 hours. The molten adduct is then treated as described above. The liquid in which the MgCl disperses or the adduct emulsifies can be any liquid that is immiscible with the molten adduct and chemically inert. For example, aliphatic, aromatic, or alicyclic hydrocarbons can be used, as can silicone oil. Aliphatic hydrocarbons such as petrolatum are particularly preferred.

[0029] The quenching liquid is preferably selected from hydrocarbons that are liquid in the temperature range of −30 to 30° C. Among these, pentane, hexane, heptane, or a mixture thereof is particularly preferred.

[0030] In both methods, the desired particle size of the final adduct is obtained by appropriately setting the fluid dynamic parameters (Reynolds number, type of rotor-stator system, etc.) that govern the formation of the adduct droplet diameter, which are related to the size of the solid particles as is well known in the art and as discussed, for example, in WO 02 / 051544, in particular pages 6-7.

[0031] In a preferred embodiment, the adduct thus obtained contains 3 to 4.5 moles of ethanol per mole of Mg.

[0032] The porosity of the solidified adduct particles can be increased by a dealcoholization step carried out according to known methodologies, such as those described in EP-A-395083, in which the adduct particles are held in a fluidized bed created by a flow of warm nitrogen, and the alcohol is removed from the adduct particles before being discharged outside the system. The dealcoholization treatment can be carried out by increasing the temperature gradient until the particles reach the desired alcohol content, which in any case is at least 10% (molar amount) lower than the initial amount.

[0033] In a preferred method according to the present disclosure, the dealcoholization treatment is carried out until the moles of alcohol per mole of Mg is in the range of 1.5 or more but less than 3.5, preferably 1.5 to 3.0.

[0034] In a preferred method for producing the catalyst of the present invention, the reaction with the Ti compound can be carried out by suspending the adduct (dealcoholized or otherwise) in TiCl4 at a temperature below 0°C, particularly in the range of -2°C to -15°C, more preferably -3°C to -10°C. Preferably, the adduct is used in an amount to provide a concentration ranging from 20 to 80 g / L, preferably 30 to 60 g / L, and particularly 35 to less than 55 g / L. According to a preferred embodiment, the electron donor (I) is added to the system at the beginning of this stage of the reaction, preferably when the mixture temperature is in the range of 10°C to 60°C. The electron donor (I) is provided in an amount to achieve the desired molar ratio in the final catalyst. In one embodiment, the molar ratio of Mg / donor (I) can be in the range of 2:1 to 15:1, preferably 3:1 to 10:1. The temperature is then gradually increased until a temperature range of 90 to 130°C is reached and maintained at this temperature for 0.5 to 3 hours.

[0035] After the reaction time is complete, stirring is stopped, the slurry is allowed to settle, and the liquid phase is removed. A second stage of treatment with TiCl4 is carried out, preferably at a temperature of 70-130°C. After the reaction time is complete, stirring is stopped, the slurry is allowed to settle, and the liquid phase is removed. Although not necessary, it is possible to carry out an additional reaction stage with a titanium compound, preferably TiCl4, under the same conditions as above, but in the absence of an electron donor. The solid thus obtained can then be washed with a liquid hydrocarbon under mild conditions and dried.

[0036] The solid catalyst component may also further comprise a small amount of an additional metal compound selected from those containing elements belonging to groups 1 to 15, preferably groups 11 to 15, of the Periodic Table of the Elements (Iupac version).

[0037] Most preferably, the compound contains an element selected from Cu, Zn, and Bi and does not contain a metal-carbon bond. Preferred compounds are oxides, carbonates, alkoxylates, carboxylates, and halides of the metals. Among these, ZnO, ZnCl, CuO, CuCl, Cu diacetate, BiCl 3、 Bicarbonate and Bicarboxylate are preferred. 3、 Bi carbonates and Bi carboxylates are particularly preferred.

[0038] Said compound can be added during the preparation of the magnesium alcohol adduct described above, or can be dispersed in a titanium compound in liquid form and introduced into the catalyst, which is then reacted with the adduct.

[0039] Whichever method is used, the final amount of the metal in the final catalyst component is in the range of 0.1 to 10 wt %, preferably 0.3 to 8 wt %, and most preferably 0.5 to 5 wt %, based on the total weight of the solid catalyst component.

[0040] The solid catalyst components according to the present disclosure are used in the polymerization of olefins by reacting them with organoaluminum compounds according to known methods.

[0041] In particular, the object of this disclosure is to provide a method for preparing olefins CH═CHR, where R is hydrogen or C1-C 12 a catalyst for the polymerization of a hydroxyl group, which is a hydrocarbyl radical, (i) a solid catalyst component of the present disclosure; and (ii) an alkylaluminum compound, and optionally (iii) an external electron donor compound, and

[0042] The alkyl-Al compound (ii) is preferably selected from trialkylaluminum compounds, such as triethylaluminum, tri-n-hexylaluminum, tri-n-octylaluminum, etc. It is also possible to use a mixture of a trialkylaluminum with an alkylaluminum halide, alkylaluminum hydride, or alkylaluminum sesquichloride (e.g., AlEt2Cl or Al2Et3Cl3).

[0043] Preferably, the aluminum alkyl compound should be used in an amount such that the Al / Ti molar ratio is in the range of 10-400, preferably 30-250, more preferably 40-200 in a gas phase process.

[0044] The mentioned catalytic system may contain an external electron donor (ED) selected from several classes. Among ethers, 1,3-diethers, which are also disclosed as internal donors in the solid catalyst component (a), are preferred. Among esters, esters of aliphatic saturated mono- or dicarboxylic acids, such as malonic acid esters, succinic acid esters, and glutaric acid esters, are preferred. Among them, the heterocyclic compound 2,2,6,6-tetramethylpiperidine is particularly preferred. A specific class of preferred external donor compounds is that of silicon compounds having at least one Si-OC bond. Preferably, the silicon compound is of the formula Ra 5 Rb 6 Si(OR 7 )c, wherein a and b are integers from 0 to 2, c is an integer from 1 to 3, and the sum (a+b+c) is 4; and R 5, R 6 , and R 7 is an alkyl, cycloalkyl, or aryl radical having 1 to 18 carbon atoms, optionally containing a heteroatom selected from N, O, halogen, and P. Methylcyclohexyldimethoxysilane, diphenyldimethoxysilane, methyl-t-butyldimethoxysilane, dicyclopentyldimethoxysilane, 2-ethylpiperidinyl-2-t-butyldimethoxysilane, 1,1-trifluoropropyl-2-ethylpiperidinyl-dimethoxysilane, and 1,1,1-trifluoropropyl-methyl-dimethoxysilane are particularly preferred. The external electron donor compound is used in an amount such that the molar ratio of the organoaluminum compound to the electron donor compound is 2 to 500, preferably 5 to 350, more preferably 7 to 200, and especially 7 to 150.

[0045] The solid catalyst component of the present disclosure is suitable for direct use in polymerization with a cocatalyst. Prepolymerization is not necessary, but can be carried out by subjecting the solid catalyst component to prepolymerization conditions in the presence of an olefin monomer and an Al-alkyl compound.

[0046] The term prepolymerization conditions refers to a complex of conditions in terms of temperature, monomer feed, and amounts of reagents suitable for preparing a prepolymerized catalyst component containing 0.1 to 500 g of polymer per gram of catalyst.

[0047] The cocatalyst used in the prepolymerization can be the same alkyl-Al compound (ii) as described above.

[0048] Prepolymerization can be carried out either in-line, i.e., in one of the reactors of a cascade polymerization process, or batchwise, in which case the final prepolymerized catalyst is recovered, isolated, and then used in a separate polymerization process.

[0049] In the case of batch prepolymerization, it has proven particularly advantageous to use small amounts of alkyl-Al compounds, in particular such that the Al compound / catalyst weight ratio ranges from 0.001 to 10, preferably from 0.005 to 5, more preferably from 0.005 to 1.5.

[0050] The prepolymerization can be carried out with any α-olefin selected in particular from the group consisting of ethylene, propylene, butene-1, 4-methyl-pentene-1, hexene-1, and octene-1.

[0051] The prepolymerization step can be carried out in the liquid or gas phase at a temperature of from 0° to 80° C., preferably from 5° to 50° C. It is particularly preferred to batch prepolymerize the catalyst of the present invention with ethylene to produce amounts of polymer in the range of from 0.5 to 20 g per gram of catalyst component.

[0052] External donors selected from previously reported silicon compounds, ethers, esters, amines, heterocyclic compounds, ketones, and 1,3-diethers of general formula (I) can also be used, although the use of an external donor in the prepolymerization is not strictly necessary.

[0053] Prepolymerization can be carried out in the liquid phase (slurry or bulk) or gas phase, generally at temperatures ranging from -20 to 80°C, preferably from 0 to 75°C. Prepolymerization is preferably carried out in a liquid diluent selected from light liquid hydrocarbons. Among these, pentane, hexane, and heptane are preferred. In an alternative embodiment, prepolymerization can be carried out in a more viscous medium, particularly one having a kinematic viscosity at 40°C ranging from 5 to 100 cSt. Such a medium can be either a pure substance or a homogeneous mixture of substances with various kinematic viscosities. Such a medium is preferably a hydrocarbon medium, more preferably having a kinematic viscosity at 40°C ranging from 10 to 90 cSt.

[0054] The olefin monomer to be prepolymerized can be fed in one step to the reactor prior to prepolymerization at a predetermined rate. In an alternative embodiment, the olefin monomer is fed continuously to the reactor during polymerization at a desired rate.

[0055] The catalysts of the present disclosure are suitable for use in any polymerization technique, and particularly in gas-phase polymerization. Gas-phase processes can be carried out in any type of gas-phase reactor. Specifically, gas-phase processes can be operated in one or more fluidized bed reactors or mechanically agitated bed reactors. In fluidized bed reactors, fluidization is achieved by the flow of a fluidizing gas, the velocity of which is no greater than the transport velocity. As a result, a bed of fluidized particles can be found in a more or less confined zone of the reactor. In mechanically agitated bed reactors, the polymer bed is held in place by gas flow generated by continuous bed motion, and adjustment of the motion also determines the bed height. The operating temperature can be 50 to 85°C, preferably 60 to 85°C, and the operating pressure can be in the range of 0.5 to 8 MPa, preferably 1 to 5 MPa, and more preferably 1.0 to 3.0 MPa. An inert fluidizing gas is also useful for dissipating the heat generated by the polymerization reaction and can be selected from nitrogen or, preferably, a light saturated hydrocarbon such as propane, pentane, hexane, or mixtures thereof.

[0056] The molecular weight of the polymer can be controlled by using an appropriate amount of hydrogen or any other molecular weight regulator, such as ZnEt2. When hydrogen is used, the hydrogen / propylene molar ratio may range from 0.0002 to 0.5, and the propylene monomer constitutes 20% to 100% by volume, preferably 30 to 70% by volume, based on the total volume of gas present in the reactor. The remainder of the feed mixture is made up of an inert gas and, if present, one or more α-olefin comonomers.

[0057] The catalyst of the present disclosure has been shown to be particularly suitable for use in gas-phase polymerization techniques comprising at least two interconnected polymerization zones. The process is carried out in first and second interconnected polymerization zones, into which propylene and ethylene, or propylene and an alpha-olefin, are fed in the presence of a catalyst system and the resulting polymer is discharged. The grown polymer particles flow under fast fluidization conditions through the first polymerization zone (riser), exit the first polymerization zone, and enter the second polymerization zone (downcomer), where they flow in a compressed form under the action of gravity, exit the second polymerization zone, and are reintroduced into the first polymerization zone, thereby establishing a polymer circulation between the two polymerization zones. The fast fluidization conditions in the first polymerization zone can be established by feeding the monomer gas mixture below the point where the grown polymer is reintroduced into the first polymerization zone. The gas transport velocity into the first polymerization zone is greater than the transport velocity under operating conditions, preferably between 2 and 15 m / s. In the second polymerization zone, where the polymer flows in a compressed form under the action of gravity, the bulk density of the polymer is reached by the arrival of solids with a higher density value, thus creating a positive pressure increase along the flow direction, allowing the polymer to be reintroduced into the first reaction zone without the aid of mechanical means. In this way, a "loop" circulation is established, defined by the pressure balance between the two polymerization zones and the head loss introduced into the system. Even in this case, an inert gas, such as nitrogen or an aliphatic hydrocarbon, can be maintained in the polymerization zone in an amount such that the sum of the partial pressures of the inert gas is preferably 5 to 80% of the total gas pressure. The operating temperature is in the range of 50 to 85°C, preferably 60 to 85°C, and the operating pressure is in the range of 0.5 to 10 MPa, preferably 1.5 to 6 MPa. Preferably, the catalyst components are fed to the first polymerization zone at any point within the first polymerization zone. However, the catalyst components can also be fed to any point within the second polymerization zone. A molecular weight regulator is used under the aforementioned conditions. By using the method described in WO 00 / 02929 it is possible to completely or partially prevent the gas mixture present in the riser from entering the downcomer.In particular, this is preferably achieved by introducing into the downcomer a gas and / or liquid mixture having a different composition from the gas mixture present in the riser. According to certain embodiments of the present disclosure, introducing into the downcomer said gas and / or liquid mixture having a different composition from the gas mixture present in the riser is effective to prevent the latter mixture from entering the downcomer. It is therefore possible to obtain two interconnected polymerization zones with different monomer compositions and, therefore, to produce polymers with different properties.

[0058] As shown in the examples, the catalyst of the present disclosure allows for a smooth transition when the polymerization conditions are changed, which is manifested by a low delta temperature between the reactor wall and the interior of the reactor. In particular, the catalyst component of the present disclosure is capable of producing various propylene polymers, such as homo- and heterophasic copolymers, with high bulk density (specifically, greater than 0.40 g / cm, preferably greater than 0.42 g / cm, along with high polymerization activity. 3 The melt flow rates of the produced polymers range from 0.1 to 100 g / 10', preferably from 1 to 70 g / 10', making the polymers suitable for a variety of end uses. Example

[0059] The following examples are given to better illustrate the present disclosure without limiting it in any way. Characterization XI Decisions

[0060] 2.5 g of polymer was dissolved in 250 ml of o-xylene with stirring at 135° C. for 30 min, then the solution was cooled to 25° C. and after 30 min the insoluble polymer was filtered off. The resulting solution was evaporated in a nitrogen flow and the residue was dried and weighed to determine the percentage of soluble polymer, followed by the XI% by difference. Average particle size of the adduct and catalyst

[0061] The measurement was carried out by a method based on the principle of optical diffraction of monochromatic laser light using a "Malvern Instr. 2600" instrument. The average size is determined by taking D50 as the diameter value at which 50% of the total volume of the particles have a diameter smaller than this value. Bulk Density ASTM D 1895 / 96 Method A Melt flow rate (MFR): Measured according to ISO 1133 (230°C, 2.16 kg) Nitrogen Porosity and Surface Area

[0062] The nitrogen porosity and surface area are measured according to the BET method (using a SORPTOMATIC 1900 manufactured by Carlo Erba). Mercury Porosity and Surface Area:

[0063] The measurements are carried out using a Carlo Erba "Porosimeter 2000 Series". Porosity is determined by absorption of pressurized mercury. For this measurement, a calibrated dilatometer (3 mm diameter) CD3 (Carlo Erba) is used, connected to a mercury reservoir and a high vacuum pump (1·10-2 mbar). A weighed sample is placed in the dilatometer. The device is then placed under high vacuum (less than 0.1 mmHg) and maintained in this state for 20 minutes. The dilatometer is then connected to the mercury reservoir and mercury is slowly allowed to flow through the dilatometer until it reaches the height of 10 cm marked on the dilatometer. The valve connecting the dilatometer to the vacuum pump is closed and the mercury pressure is gradually increased with nitrogen to 140 mg / cm. 2 Under the influence of pressure, the mercury enters the pores and the level drops according to the porosity of the material.

[0064] Porosity (cm 3 / g) is the porosity up to 1 μm for the catalyst (10 μm for the polymer), the pore distribution curve, and the average pore diameter, are calculated directly from the integrated pore distribution curve, which is a function of the volume loss of the mercury and the applied pressure value (all these data are provided and generated by the computer attached to the porosimeter, equipped with a C. Erba "MILESTONE 200 / 2.04"). General Procedure for Propylene Polymerization Testing

[0065] The propylene copolymer compositions in the examples were prepared in a single gas-phase polymerization reactor containing two interconnected polymerization zones, a riser, and a downcomer, as described in the General Polymerization Procedures section of WO 00 / 02929, except that no barrier feed was installed. The reactor was equipped with a pair of heat probes located below the downcomer to measure the temperature difference between the wall temperature and the reactor interior during transition. Triethylaluminum (TEAL) was used as a cocatalyst and dicyclopentyldimethoxysilane as an external donor in the weight ratios shown in the examples. Starting from specific operating conditions, transitions to different polymer grades were performed by varying the polymerization conditions to produce the specific polymer grades shown in each example. During the transition period, the delta temperature between the reactor wall and the reactor interior was measured as an evaluation of smooth operation. Example Example 1 Catalyst carrier

[0066] At -8°C, 100g of MgCl2 and 3.2g of water were introduced into a vessel reactor equipped with an IKA RE 166 stirrer and containing 183.5g of absolute EtOH, with stirring. After the addition of MgCl2 was complete, the temperature was raised to 108°C and maintained at this value for 20 hours. Then, while maintaining the temperature at 108°C, the melt was fed by a volumetric pump set at 260ml / min to an emulsification unit operating at 1500 rpm, together with OB55 oil fed by a volumetric pump set at 1100ml / min, to produce an emulsion of melt and oil. While continuously feeding the melt and oil, the mixture was continuously discharged at 108°C into a vessel containing 5 liters of chilled hexane, which was maintained under stirring and cooled so that the final temperature did not exceed 12°C. After 24 hours, the recovered solid particles of the adduct were washed with hexane and dried under vacuum at 40 °C, resulting in a D50 diameter of 68.6 μm. The adduct was then thermally dealcoholized in a fluidized bed under increasing temperature nitrogen flow until the EtOH content reached a chemical composition of 50.2 wt% EtOH and 1.4 wt% HO, with the remainder being MgCl. Preparation of the final catalyst component

[0067] A 2.0-liter round-bottom flask equipped with a mechanical stirrer, condenser, and thermometer was charged with 1.0 liters of TiCl4 at room temperature under a nitrogen atmosphere. After cooling to -5°C, 54 g of the microspheroids prepared as described above was added with stirring. The temperature was then increased from -5°C to a maximum of 40°C at a rate of 0.3°C / min, and 9,9-bis(methoxymethyl)fluorene was added in an amount to achieve a Mg / diether molar ratio of 8. The temperature was then increased to 100°C in 50 minutes. The TiCl4 treatment was repeated for an additional 50 minutes at 110°C, followed by another 30 minutes at 110°C, with a Mg / diether molar ratio of 21 (5.8 ml total). The solid was then washed five times with anhydrous hexane (5 x 900 ml) at 60°C.

[0068] Finally, the solid was dried under vacuum and analyzed. The final catalyst component had a particle size of 67.3 μm and a mass of 284 μm. 2 / g surface area (BET), and 0.213 cm 3 / g porosity (BET).

[0069] In terms of catalyst composition, the amount of Ti was 4.2 wt % and the amount of 9,9-bis(methoxymethyl)fluorene was 16.8 wt %.

[0070] Polymerization (homo-laco transition) A first propylene homopolymer having the characteristics shown in Table 1 and under the polymerization conditions was prepared in the reactor setup described in the general procedure. Table 1 [Table 1]

[0071] The transition to a propylene copolymer grade was initiated by introducing ethylene into the gaseous reactor mixture to produce a copolymer having the reported characteristics under the following reaction conditions as steady state: Table 2 [Table 2]

[0072] The transition period lasted approximately 3 hours. At the beginning of the transition, the delta temperature between the surface and interior of the reactor at the bottom of the downcomer was 7.8° C. During the transition, the delta temperature reached a value of 9.1° C., resulting in a maximum difference of 1.3° C. Comparative Example 1

[0073] The same polymerization procedure and transition time was replicated except that the catalyst used was prepared as follows: Preparation of catalyst support

[0074] Initial amounts of MgCl2·2.8C2H5OH adduct were prepared according to the methodology described in Example 2 of PCT Publication No. WO 98 / 44009, but operated on a larger scale.

[0075] The adduct was then thermally dealcoholized under temperature-increasing nitrogen flow until the EtOH content reached a chemical composition of 49.7 wt.% EtOH and 1.2 wt.% water and the particle size D50 reached 52.0 μm. Preparation of the final catalyst component

[0076] A 2.0-liter round-bottom flask equipped with a mechanical stirrer, condenser, and thermometer was charged with 1.0 liters of TiCl4 at room temperature under a nitrogen atmosphere. While cooling at 0°C, 50 g of microspheroids prepared as described in the general procedure were added. The temperature was then increased from 0°C to a maximum of 40°C at a rate of 0.4°C / min, and 9,9-bis(methoxymethyl)fluorene was added in an amount to achieve a Mg / diether molar ratio of 5. The temperature was then increased to 100°C in 50 minutes. The TiCl4 treatment was repeated at 109°C for 20 minutes, then at 109°C for 15 minutes. The solid was then washed five times with anhydrous hexane (5 x 900 ml) at 50°C.

[0077] Finally, the solid was dried under vacuum and analyzed. The final catalyst component had a particle size of 53.7 μm and a mass of 65 μm. 2 The surface area (BET) is shown in g.

[0078] In terms of catalyst composition, the amount of Ti was 4.3 wt % and the amount of 9,9-bis(methoxymethyl)fluorene was 15.4 wt %. Polymerization (homo-laco transition)

[0079] The same polymerization procedure and transition time were carried out as in Example 1. At the beginning of the transition, the delta temperature between the surface and the interior of the reactor at the bottom of the downcomer was −1.3° C. During the transition, the delta temperature reached a value of 6.4° C., resulting in a maximum difference of 7.7° C. Example 2 Preparation of the final catalyst component

[0080] A 2.0-liter round-bottom flask equipped with a mechanical stirrer, condenser, and thermometer was charged with 1.0 liters of TiCl4 at room temperature under a nitrogen atmosphere. After cooling to -5°C, 45 g of the microspheroids prepared in Example 1 were added with stirring. The temperature was then increased from -5°C to a maximum of 40°C at a rate of 0.3°C / min, and 9,9-bis(methoxymethyl)fluorene was added in an amount to achieve a Mg / diether molar ratio of 8. The temperature was then increased to 100°C in 45 minutes. The TiCl4 treatment was repeated for 45 minutes at 109°C in the presence of additional Mg / diether in a molar ratio of 21, followed by a third time at 109°C for 25 minutes. The solid was then washed five times with anhydrous hexane (5 x 900 ml) at 50°C.

[0081] Finally, the solid was dried under vacuum and analyzed. The final catalyst component had a particle size of 66.5 μm, a mass of 174 μm 2 / g surface area (BET), and 0.183 cm 3 / g porosity (BET).

[0082] In terms of catalyst composition, the amount of Ti was 4.2 wt %, and the amount of 9,9-bis(methoxymethyl)fluorene was 17.9 wt %. Polymerization (transition from Laco low MFR to Laco high MFR)

[0083] A first propylene ethylene copolymer, having the characteristics and under the polymerization conditions shown in Table 3, was prepared in the reactor setup described in the general procedure. Table 3 [Table 3]

[0084] Under the following reaction conditions as steady state, the transition to higher melt flow rate propylene ethylene copolymer grades was initiated by increasing the hydrogen fed to the gaseous reactor mixture to produce copolymers with the reported characteristics: Table 4 [Table 4]

[0085] The transition period lasted approximately 5 hours. At the beginning of the transition, the delta temperature between the surface and the interior of the reactor at the bottom of the downcomer was 6.0°C. During the transition, the delta temperature reached a value of 5.5°C, so the maximum difference was -0.5°C. The production of the copolymer grade was completed without any observed reactor fouling. Comparative Example 2

[0086] The same polymerization procedure and transition conditions used in Example 2 were replicated, except that the catalyst of Comparative Example 1 was used. At the start of the transition, the delta temperature between the surface and interior of the reactor at the bottom of the downcomer was 2.0°C. At the end of the transition, the delta temperature value reached 11.3°C, resulting in a maximum difference of 9.3°C. Inspection of the reactor at the end of production revealed a significant amount of fouling.

Claims

1. A solid catalyst component for the polymerization of olefins comprising an internal donor selected from Ti, Mg, and 1,3-diethers, characterized in that the solid catalyst component has an average particle size (D50) in the range of 55-80 μm as measured by the optical diffraction method as reported herein, and a surface area (SA) as measured by the BET method as reported herein, such that the value of the formula SA×D50 / 100 is greater than 60.

2. 2. The solid catalyst component according to claim 1, wherein the value of the formula SA x D50 / 100 is greater than 80.

3. 3. The solid catalyst component according to claim 2, wherein the value of the formula SA x D50 / 100 is greater than 100.

4. A solid catalyst component according to any one of the preceding claims, having an average particle size D50 in the range of 55 to 75 μm.

5. The porosity (P) reported in the specification as measured by the BET method is 0.18 cm ３ / g, preferably 0.19 cm ３ 10. The solid catalyst component according to claim 1, wherein the saturation coefficient is greater than 1 / g.

6. The surface area (SA) is 180 to 400 m ２ 10. The solid catalyst component according to claim 1, wherein the SiO2 content is in the range of 0.1 wt. / g.

7. The surface area (SA) is 200 to 350 m ２ The solid catalyst component according to claim 6, wherein the SiO2 content is in the range of 1 / g.

8. 10. A solid catalyst component according to any one of the preceding claims, wherein the value of the formula SA×P is greater than 10.

9. 9. The solid catalyst component according to claim 8, wherein the value of the formula SA×P is greater than 20.

10. A solid catalyst component according to any one of the preceding claims, wherein said 1,3-diether is selected from compounds of formula (I): 【Chemical 1】 (I) In the formula, R Ｉ and R ＩＩ are the same or different and are hydrogen or straight or branched chain C which may also form one or more cyclic structures. １ -C １８ R are hydrocarbon groups, and may be equal or different from each other. ＩＩＩ The group is hydrogen or C １ -C １８ R are hydrocarbon groups, and may be equal or different from each other. ＩＶ The group R ＩＩＩ has the same meaning as R Ｉ ~R ＩＶ Each of the groups may contain heteroatoms selected from halogen, N, O, S, and Si.

11. 10. The solid catalyst component according to claim 9, wherein said 1,3-diethers are selected from those of formula (III): 【Chemistry 2】 (III) In the formula, R ＩＩＩ and R ＩＶ The radicals have the same meaning as defined in formula (I), R ＶＩ The radicals may be equal or different and may be hydrogen; halogens, preferably Cl and F; straight or branched chain C １ -C ２０ Alkyl radical; C ３ -C ２０ Cycloalkyl, C ６ -C ２０ Aryl, C ７ -C ２０ alkylaryl, and C ７ -C ２０ An aralkyl radical, optionally containing one or more heteroatoms selected from the group consisting of N, O, S, P, Si, and halogens, particularly Cl and F, as substituents to carbon or hydrogen atoms, or both.

12. Olefin CH ２ Catalyst systems for the polymerization of =CHR, where R is hydrogen or a hydrocarbyl radical containing 1 to 12 carbon atoms, (i) Precedence A solid catalyst component according to any one of claims 1 to 4, (ii) an alkylaluminum compound, and optionally (iii) an external electron donor compound; and

13. The external electron donor has the formula R ａ ５ R ｂ ６ Si(OR ７ ) ｃ wherein a and b are integers from 0 to 2, c is an integer from 1 to 3, the sum (a+b+c) is 4, and R ５ , R ６ , and R ７ is an alkyl, cycloalkyl, or aryl radical having 1 to 18 carbon atoms, optionally containing heteroatoms selected from N, O, halogen, and P.

14. 14. The process for producing an olefin CH ２ =CHR (wherein R is C １ -C １２ A gas phase process for the polymerization of olefins (e.g., olefins containing olefins having hydrocarbyl groups).

15. 15. The gas phase process of claim 14 carried out in a reactor comprising at least first and second interconnected polymerization zones, wherein the polymer particles flow under fast fluidization conditions through the first polymerization zone (riser) and exit the first polymerization zone into the second polymerization zone (downcomer), where the polymer particles flow in a compressed form under the action of gravity, thereby establishing a polymer circulation between the two polymerization zones.

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