Catalyst components for the polymerization of olefins

Abstract

A catalyst component for the polymerization of olefins comprising Ti, Mg and at least two internal electron donor (ID) compounds one of which being selected from 1,3-diethers (DE) and the other being selected from alkyl esters of non-substituted dicarboxylic aliphatic acids (NSDAE), said catalyst component being characterized by the fact that the molar ratio ID / Ti is from 0.40 to 1.60, where ID is the total molar amount of (NSDAE) and (DE), and the molar ratio between (DE) and (NSDAE) ranges from 0.70 to 6.0.

Description

TITLECATALYST COMPONENTS FOR THE POLYMERIZATION OF OLEFINSFIELD OF THE DISCLOSURE

[0001] The present disclosure relates to catalyst components for the polymerization of olefins, in particular propylene, comprising a Mg dihalide, a Ti compound having at least one Ti-halogen bond and at least two electron donor compounds selected from specific classes.BACKGROUND OF THE DISCLOSURE

[0002] Most of the polypropylene catalysts used nowadays are based on titanium species and electron donor compounds (internal donors) supported on Mg based supports. These catalyst components are used in combination with an aluminium alkyl cocatalyst and with alkylalkoxysilanes as selectivity control agents (external donors) for the production of a variety of polypropylene based products. Phthalate based compounds have been very commonly used as internal donors in commercial catalysts.

[0003] However, increasing toxicological concerns towards the use of phthalates have driven the efforts to find acceptable or even improved alternatives.

[0004] WO2012 / 139897 for example discloses catalyst components in which mixtures of substituted succinates and 1,3-diethers replace phthalates as internal donors. The use of the mixture generates a catalyst which offers good performances in terms of activity and stereospecificity which are key properties for a commercial catalyst.

[0005] An additional desired property for the commercial catalysts Ziegler-Natta catalysts is the capability to produce polypropylene which maintain the requested tacticity even increasing the melt flow rate. A melt flow rate of a relatively high value will enable a polymer to be more easily formed into the intended article which, for certain applications, is a crucial feature .

[0006] High melt flow rate propylene polymers, also known as “controlled rheology” propylene polymers, can be obtained in the art by subjecting polypropylene to an additional peroxide treatment (“vis-breaking”) to reduce the initial length of the polymer chains thus increasing the melt flow rate of the polymer. The major drawback of this technology is that the peroxide is included in the polymer which tends to turn yellow with time and that also molecular1FE7752-WO-01weight distribution is affected. As a consequence, the possibility to control melt flow rate (molecular weight) during polymerization by varying the amount of chain transfer agent (for example hydrogen) in the reactor is the common choice at commercial scale. However, in bulk polymerization, the amount of hydrogen introduced is limited by its solubility in the liquid polymerization medium and by operative pressure of the reactor. It would be therefore desired to use a catalyst having an improved “hydrogen response” that means the capability of the catalyst to produce a polymer with reduced molecular weight in respect of a certain amount of hydrogen in the reaction system.

[0007] In this respect, it would be advisable to improve the hydrogen response of the catalyst disclosed in WO2012 / 139897 in order to meet the melt flow rate target for specific injection molding applications.

[0008] It has now been found that by using specific esters in the internal donor mixture, a catalyst having an improved hydrogen response can be obtained.SUMMARY OF THE DISCLOSURE

[0009] It is therefore an object of the present application a catalyst component for the polymerization of olefins comprising Ti, Mg and at least two internal electron donor (ID) compounds one of which being selected from 1,3 -di ethers (DE) and the other being selected from alkyl esters of non-substituted dicarboxy lie aliphatic acids (NSDAE), said catalyst component being characterized by the fact that the molar ratio ID / Ti is from 0.40 to 1.60, where ID is the total molar amount of (NSDAE) and (DE), and the molar ratio between (DE) and (NSDAE) ranges from 0.70 to 6.0.DETAILED DESCRIPTION OF THE DISCLOSURE

[0010] Preferably, the solid catalyst component has an average particle size D50 ranging from 15 to 100 pm more preferably from 30 to 90 pm and especially from 40 to 80 pm.

[0011] Preferably, the catalyst component has a porosity (P) measured by the BET method higher than 0.18 cm3 / g, preferably higher than 0.19 cm3 / g and more preferably ranging from 0.20 to 0.25 cm3 / g.

[0012] The (DE) internal donor is preferably selected from the 1,3-diethers of formula (I)2FE7752-WO-01where R1and Rnare the same or different and are hydrogen or linear or branched Ci-Cis hydrocarbon groups which can also form one or more cyclic structures; R111groups, equal or different from each other, are hydrogen or Ci-Cis hydrocarbon groups; RIVgroups equal or different from each other, have the same meaning of R111except that they cannot be hydrogen; each of R1to RIVgroups can contain heteroatoms selected from halogens, N, O, S and Si.

[0013] Preferably, RIVis a 1-6 carbon atom alkyl radical and more particularly a methyl while the R111radicals are preferably hydrogen. Preferably, R1and Rncan be, independently, hydrogen, methyl, ethyl, propyl, isopropyl, butyl, isobutyl, tert-butyl, isopentyl, 2-ethylhexyl, cyclopentyl, cyclohexyl, methylcyclohexyl, phenyl or benzyl. Particularly preferred are the structures in which R1is a linear or branched primary alkyl group containing at least three carbon atoms such as butyl, isobutyl, isopentyl, 2-ethylhexyl and Rnis a secondary alkyl or cycloalkyl group such as isopropyl, cyclopentyl and cyclohexyl.

[0014] When R1is hydrogen, Rncan be ethyl, butyl, sec-butyl, tert-butyl, 2-ethylhexyl, cyclohexylethyl, diphenylmethyl, p-chlorophenyl, 1 -naphthyl, 1 -decahydronaphthyl.

[0015] Specific examples of ethers that can be used include: 2-(2-ethylhexyl)l,3-dimethoxypropane, 2-isopropyl-l,3-dimethoxypropane, 2-butyl-l,3-dimethoxypropane, 2-sec-butyl- 1,3 -dimethoxypropane, 2-cyclohexy 1-1, 3 -dimethoxypropane, 2-phenyl-l,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, 2-(p-chlorophenyl)-l,3-dimethoxypropane, 2-(diphenylmethyl)- 1,3 -dimethoxypropane, 2(l-naphthyl)-1 ,3-dimethoxypropane, 2(p-fluorophenyl)-l ,3-dimethoxypropane, 2(1 -decahydronaphthyl)- 1 ,3-dimethoxypropane, 2(p-tert-butylphenyl)- 1 ,3-dimethoxypropane, 2,2-dicyclohexyl-l ,3-dimethoxypropane, 2, 2-diethyl- 1,3 -dimethoxypropane, 2,2-dipropyl-l,3-dimethoxypropane, 2,2-dibutyl-l,3-dimethoxypropane, 2, 2-diethyl- 1,3 -di ethoxypropane, 2, 2-di cyclopentyl- 1,3-3FE7752-WO-01dimethoxypropane, 2, 2-dipropyl- 1,3 -di ethoxypropane, 2,2-dibutyl-l,3-diethoxypropane, 2-methyl-2-ethyl-l,3-dimethoxypropane, 2-methyl-2-propyl-l,3-dimethoxypropane, 2-methyl-2-benzyl- 1 ,3 -dimethoxypropane, 2-methyl-2-phenyl-l ,3 -dimethoxypropane, 2-methyl-2-cyclohexyl- 1 ,3 -dimethoxypropane, 2-methyl-2-methylcyclohexyl- 1 ,3 -dimethoxypropane, 2,2-bis(p-chlorophenyl)-l,3-dimethoxypropane, 2,2-bis(2-phenylethyl)-l,3-dimethoxypropane, 2,2-bis(2-cyclohexylethyl)-l ,3-dimethoxypropane, 2-methyl-2-isobutyl- 1 ,3-dimethoxypropane, 2-methyl-2-(2-ethylhexyl)-l,3-dimethoxypropane, 2,2-bis(2-ethylhexyl)-l,3-dimethoxypropane,2,2-bis(p-methylphenyl)-l,3-dimethoxypropane, 2-methyl-2-isopropyl-l,3-dimethoxypropane, 2,2-diisobutyl-l,3-dimethoxypropane, 2, 2-diphenyl- 1,3 -dimethoxypropane, 2.2-dibenzyl-l,3-dimethoxypropane, 2-isopropyl-2-cyclopentyl-l,3-dimethoxypropane, 2,2-bis(cyclohexylmethyl)- 1,3 -dimethoxypropane, 2,2-diisobutyl-l,3-diethoxypropane, 2,2-diisobutyl-l,3-dibutoxypropane, 2-isobutyl-2-isopropyl-l,3-dimetoxypropane, 2,2-di-sec-butyl- 1.3-dimetoxypropane, 2, 2-di -tert-butyl- 1,3 -dimethoxypropane, 2,2-dineopentyl-l,3-dimethoxypropane, 2-iso-propyl-2-isopentyl-l,3-dimethoxypropane, 2-phenyl-2-benzyl-l,3-dimetoxypropane, 2-cyclohexyl-2-cyclohexylmethyl-l,3-dimethoxypropane.

[0016] Furthermore, particularly preferred are the 1,3-diethers of formula (II)where the radicals RIVhave the same meaning defined in formula (I) and the radicals R111and Rv, equal or different to each other, are selected from the group consisting of hydrogen; halogens, preferably Cl and F; C1-C20 alkyl radicals, linear or branched; C3-C20 cycloalkyl, C6-C20 aryl, C7-C20 alkylaryl and C7-C20 arylalkyl radicals and two or more of the Rvradicals can be bonded to each other to form condensed cyclic structures, saturated or unsaturated, optionally substituted with RVIradicals selected from the group consisting of halogens, preferably Cl and F; C1-C20 alkyl radicals, linear or branched; C3-C20 cycloalkyl, C6-C20 aryl, C7-C20 alkaryl and C7-C20 aralkyl4FE7752-WO-01radicals; said radicals Rvand RVIoptionally containing one or more heteroatoms as substitutes for carbon or hydrogen atoms, or both.

[0017] Preferably, in the 1,3-diethers of formulae (I) and (II) all the R111radicals are hydrogen, and all the RIVradicals are methyl. Moreover, are particularly preferred the 1,3-diethers of formula (II) in which two or more of the Rvradicals are bonded to each other to form one or more condensed cyclic structures, preferably benzenic, optionally substituted by RVIradicals. Especially preferred are the compounds of formula (III):where the R111and RIVradicals have the same meaning defined in formula (I), RVIradicals equal or different are hydrogen; halogens, preferably Cl and F; C1-C20 alkyl radicals, linear or branched; C3-C20 cycloalkyl, C6-C20 aryl, C7-C20 alkylaryl and C7-C20 aralkyl radicals, optionally containing one or more heteroatoms selected from the group consisting of N, O, S, P, Si and halogens, in particular Cl and F, as substitutes for carbon or hydrogen atoms, or both.

[0018] Specific examples of compounds comprised in formulae (II) and (III) are: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;5FE7752-WO-011 , 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;l,l-bis(methoxymethyl)-7-(3,3,3-trifluoropropyl)indene;1 , 1 -bis(methoxymethyl)-7-trimethyisilylindene;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-cyclopenthylindene;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)-lH-benz[e] indene;1 , 1 -bis(methoxymethyl)- 1 H-2-methylbenz[e] indene;9.9-bis(methoxymethyl)fluorene;9.9-bis(methoxymethyl)-2,3,6,7-tetramethylfluorene;9.9-bis(methoxymethy 1) -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)-l,8-dichlorofluorene;9.9-bis(methoxymethyl)-2,7-dicyclopentylfluorene;9.9-bis(methoxymethyl)-l,8-difluorofluorene;9.9-bis(methoxymethyl)- 1 ,2,3,4-tetrahydrofluorene;9.9-bis(methoxymethyl)-l,2,3,4,5,6,7,8-octahydrofluorene;9.9-bis(methoxymethyl)-4-tert-butylfluorene.6FE7752-WO-01

[0019] The preferred (NSDAE) is selected from alkyl esters of non- substituted dicarboxylic aliphatic acids, saturated or unsaturated, having from 3 to 8 carbon atoms. Preferably, they are selected from diester of formula (IV) ROOC-(CH2)n-COOR in which n is an integer from 1 to 4 and the R groups, equal to or different from each other, are Ci-Cio alkyl groups.

[0020] Preferably, (NSDAE) is selected from the compounds of formula (IV) in which R is a Ci-Ce linear or branched alkyl, preferably ethyl or isobutyl.

[0021] In a particularly preferred embodiment, (NSDAE) is selected from the compounds of formula (IV) in which n is preferably from 1 to 3.

[0022] Non limitative examples of esters (c) are diethyl maleate, diethyl malonate, diethyl succinate, diethyl glutarate, diethyl adipate, diethyl suberate, diethyl pimelate and the corresponding esters deriving from substitution of ethyl with methyl, isobutyl, or 2-ethylhexyl.

[0023] Additional electron donors different from (DE) and (NSDAE) di ethers can be present as well in a very minor amount. When present, additional donors are preferably selected from alcohols or mono carboxylic acid esters and their molar amount is preferably less than 25% the amount of 1,3-diethers.

[0024] Preferably, the molar ratio between the ID (NSDAE+DE) and the Ti atoms in the final solid catalyst component ranges from 0.5:1 to 1.5:1 and more preferably from 0.6:1 to 1.3:1.

[0025] Preferably, the molar ratio between the Mg atoms and the ID in the final solid catalyst component ranges from 4.0:1 to 16.0:1 and more preferably from 5.0:1 to 15.0:1.

[0026] In a preferred embodiment the Mg / Ti molar ratio ranges from 5 to 20, preferably from 6 to 15 and especially ranging from 7 to 13.

[0027] In a preferred embodiment, the molar ratio between (DE) and (NSDAE) ranges from 0.90 to 5.50, preferably from 1.0 to 5.0, more preferably in the range 1.2- 4.8.

[0028] The solid catalyst component comprises, in addition to the above mentioned electron donors, a titanium compound having at least a Ti-halogen bond and a Mg halide. The magnesium halide is preferably MgCh in active form which acts as a support for Ti compounds and donors. Patents USP 4,298,718 and USP 4,495,338 were the first to describe the use of these compounds in Ziegler-Natta catalysis. The magnesium dihalides in active form used as support or co-support in components of catalysts for the polymerization of olefins are characterized by X-ray spectra in which the most intense diffraction line that appears in the spectrum of the non-active halide is7FE7752-WO-01diminished in intensity and is replaced by a halo whose maximum intensity is displaced towards lower angles relative to that of the more intense line.

[0029] The preferred titanium compounds used in the catalyst component of the present disclosure are TiCh and TiCh; furthermore, also Ti-haloalcoholates of formula Ti(OR)n-yXy can be used, where n is the valence of titanium, y is a number between 1 and n-1 X is halogen and R is a hydrocarbon radical having from 1 to 10 carbon atoms.

[0030] The preparation of the solid catalyst component can be carried out according to several methods. According to a preferred method, the solid catalyst component can be prepared by reacting a titanium compound of formula Ti(0R5)m-yXy, where m is the valence of titanium and y is a number between 1 and m, preferably TiCh, with a magnesium chloride deriving from an adduct of formula MgC12*pR6OH, where p is a number between 1.5 and 4.5, and R6is a hydrocarbon radical having 1-18 carbon atoms. According to the preferred one, an adduct between magnesium chloride and alcohol (in particular ethanol) containing from 1.5 to 4.0 moles of alcohol per mole of Mg is used.

[0031] The adduct can be prepared by contacting MgCh and alcohol in the absence of the inert liquid dispersant, heating the system at the melting temperature of MgCh-alcohol adduct or above, and maintaining said conditions so as to obtain a completely melted adduct. In particular, the adduct is preferably kept at a temperature equal to or higher than its melting temperature, under stirring conditions, for a time period equal to, or greater than, 1 hour, preferably from 2 to 15 hours, more preferably from 5 to 10 hours. Said molten adduct is then emulsified in a liquid medium which is immiscible with and chemically inert to it and finally quenched by contacting the adduct with an inert cooling liquid thereby obtaining the solidification of the adduct. It is also preferable, before recovering the solid particles, to leave them in the cooling liquid at a temperature ranging from -10 to 25°C for a time ranging from 1 to 24 hours.

[0032] In a variant to this method, MgCh particles can be dispersed in an inert liquid immiscible with and chemically inert to the molten adduct, heating the system at temperature equal to or higher than the melting temperature of MgCh*ethanol adduct and then adding the desired amount of alcohol in vapor phase. The temperature is kept at values such that the adduct is completely melted for a time ranging from 10 minutes to 10 hours. The molten adduct is then treated as disclosed above. The liquid in which the MgCh is dispersed, or the adduct emulsified, can be any liquid immiscible with and chemically inert to the molten adduct. For example,8FE7752-WO-01aliphatic, aromatic or cycloaliphatic hydrocarbons can be used as well as silicone oils. Aliphatic hydrocarbons such as vaseline oil are particularly preferred.

[0033] The quenching liquid is preferably selected from hydrocarbons that are liquid at temperatures ranging from -30 to 30°C. Among them preferred are pentane, hexane, heptane or mixtures thereof.

[0034] In both methods the desired particle size of the final adduct is obtained by properly setting the fluid dynamic parameters (Reynolds number, type of rotor stator systems, etc) governing the formation of adduct droplet size, which are in relation to the size of the solid particles, according to what is disclosed for example in W002 / 051544 particularly at pages 6-7.

[0035] In a preferred embodiment, the final adduct contains from 3:1 to 4.5:1 mols of ethanol per mol of Mg.

[0036] The porosity of the solidified adduct particles can be increased by a dealcoholation step carried out for example as described in EP-A-395083 in which dealcoholation is obtained by keeping the adduct particles in a fluidized bed created by the flowing of warm nitrogen which after removal of the alcohol from the adduct particles is directed out of the system. The dealcoholation treatment may be carried out at increasing temperature gradient until the particles have reached the desired alcohol content which is in any case at least 10% (molar amount) lower than the initial amount.

[0037] In the preferred method according to the present disclosure, the dealcoholation treatment is carried out until moles of alcohol per mole of Mg range from 1.5 to less than 3.5 preferably from 1.5 to 3.0.

[0038] In the preferred method of producing the catalyst of the disclosure, the reaction with the Ti compound can be carried out by suspending the adduct (dealcoholated or as such) in TiCh at a temperature of 0°C or below , in particularly ranging from -2°C to -15°C and more preferably from -3°C to -10°C. Preferably the adduct is used in an amount such as to have a concentration ranging from 20 to 80 g / 1, preferably from 30 to 60 g / 1. The temperature is then gradually raised up until reaching a temperature ranging from 90-130°C and kept at this temperature for 0.5-3 hours.After completing the reaction time stirring is stopped, the slurry is let to settle, and liquid phase removed. A second stage of treatment with TiCh is performed, preferably carried out at a temperature ranging from 70 to 130°C. After completing the reaction time, stirring is stopped, the slurry is let to settle, and liquid phase removed. It is possible, although not necessary, to carry out9FE7752-WO-01additional reaction stage with the titanium compound and preferably with TiCh under the same conditions described above and in the absence of electron donors. The so obtained solid can then be washed with liquid hydrocarbon under mild conditions and then dried.According to a preferred embodiment, the (NSDAE) and (DE) are added to the system at the beginning of a stage of reaction with the Ti compound described above. Although it is possible to add them simultaneously, it is preferred to feed them in separate reaction steps. In a preferred embodiment, (NSDAE) is added during the first treatment with the titanium compound when the temperature of the mixture is in the range of 10°C to 60°C. The (NSDAE) is fed in amounts such as to meet the desired molar ratio in the final catalyst. In an embodiment the Mg / (NSDAE) molar ratio used in this stage may range from 15:1 to 50: 1 and preferably from 20: 1 to 40: 1.

[0039] Preferably, DE is added during the second treatment with the titanium compound when the temperature of the mixture is in the range of 10°C to 60°C. The DE is fed in amounts such as to meet the desired molar ratio in the final catalyst. In an embodiment, the Mg / DE molar ratio used in this stage may range from 1:1 to 20: 1 and preferably from 3:1 to 15:1.

[0040] In another preferred embodiment, DE and (NSDAE) feeding are inverted with DE being added during first reaction step and (NSDAE) during the second although their Mg / donor feeding ratio are maintained in the ranges disclosed above.

[0041] The solid catalyst component of the present disclosure may also contain a small amount of additional metal compounds selected from those containing elements belonging to group 1-15 preferably groups 11-15 of the periodic table of elements (lupac version).

[0042] Most preferably, said compounds include elements selected from Cu, Zn, and Bi not containing metal-carbon bonds. Preferred compounds are the oxides, carbonates, alkoxylates, carboxylates and halides of said metals. Among them, ZnO, ZnCh, CuO, CuCh, and Cu diacetate, BiCh, Bi carbonates and Bi carboxylates are preferred. BiCh, Bi carbonates and Bi carboxylates are especially preferred.

[0043] The said compounds can be added either during the preparation of the previously described magnesium-alcohol adduct or they can be introduced into the catalysts by dispersing them into the titanium compound in liquid form which is then reacted with the adduct.

[0044] Whichever the method used, the final amount of said metals into the final catalyst component ranges from 0.1 to 10% wt, preferably from 0.3 to 8% and most preferably from 0.5 to 5% wt with respect to the total weight of solid catalyst component.10FE7752-WO-01

[0045] 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.

[0046] In particular, it is an object of the present disclosure a catalyst for the polymerization of olefins CH2=CHR, wherein R is hydrogen or a C1-C12 hydrocarbyl radical comprising the product of the reaction between:(i) the solid catalyst component of the present disclosure and(ii) an alkylaluminum compound and, optionally,(iii) an external electron donor compound.

[0047] The alkyl-Al compound (ii), is preferably chosen among the trialkyl aluminum compounds such as for example triethylaluminum, tri-n-hexylaluminum, tri-n-octylaluminum. It is also possible to use mixtures of trialkylaluminum's with alkylaluminum halides, alkylaluminum hydrides or alkylaluminum sesquichlorides such as AlEt2Cl and AhEtsCh.

[0048] Preferably, the aluminum alkyl compound should be used in the gas-phase process in amount such that the Al / Ti molar ratio ranges from 10 to 400, preferably from 30 to 250 and more preferably from 40 to 200.

[0049] As mentioned the catalyst system may include external electron-donors (ED) selected from several classes. Among ethers, preferred are the 1,3 -di ethers also disclosed as internal donors in the solid catalyst component (a). Among esters, preferred are the esters of aliphatic saturated mono or dicarboxylic acids such as malonates, succinates and glutarates. Among heterocyclic compounds 2,2,6,6-tetramethyl piperidine is particularly preferred. A specific class of preferred external donor compounds is that of silicon compounds having at least a Si-O-C bond. Preferably, said silicon compounds are of formula Ra5Rb6Si(OR7)c, where a and b are integer from 0 to 2, c is an integer from 1 to 3 and the sum (a+b+c) is 4; R5, R6, and R7, are alkyl, cycloalkyl or aryl radicals with 1-18 carbon atoms optionally containing heteroatoms selected from N, O, halogen and P. Particularly preferred are methylcyclohexyldimethoxysilane, diphenyldimethoxysilane, methyl-t-butyldimethoxysilane, dicyclopentyldimethoxysilane, 2-ethylpiperidinyl-2-t-butyldimethoxysilane and 1 , 1 , 1 ,trifhroropropyl-2-ethylpiperidinyl-dimethoxysilane and l,l,l,trifhroropropyl-metil-dimethoxysilane. The external electron donor compound is used in such an amount to give a molar ratio between the organo-aluminum compound and said electron donor11FE7752-WO-01compound of from 2 to 500, preferably from 5 to 350, more preferably from 7 to 200 and especially from 7 to 150.

[0050] The catalyst of the present disclosure shows high activity and stereospecificity coupled with a high hydrogen response (HR). In particular, the polymerization activity in bulk polymerization may range from 20 to 70 kg PP / gcat in the presence of an external donor and can reach more than 100 kgPP / gcat in the absence of external donor.

[0051] The sterespecificity, expressed as insolubility in xylene at 25°C, is higher than 97.0% and preferably higher than 97.5%wt when the polymerization is carried out in the presence of an external donor.

[0052] In combination with the high activity and stereospecificity the HR is also high. A single numerical value describing (HR) can be calculated for a given catalyst by summing up the melt flow rate values (determined according to ISO 1133 (230°C, 2.16 Kg) obtained by a series of polymerization runs at increasing hydrogen concentrations and dividing the obtained value by the total volume (in liters) of hydrogen obtained by summing up the specific volume of hydrogen used in each polymerization of the series. The HR value so calculated for the catalyst of the present disclosure is at least higher than 8.0 preferably at least 10 when the polymerizations are carried out in the presence of an external donor. It has to be noted that this value is higher than the HR value obtained for the catalyst of WO2012 / 139897 which, at best, is about 6.5.

[0053] When the polymerizations are carried out in the absence of external donors the HR for the catalyst of the present disclosure ranges from about 20 to 45, while the prior art catalyst are, at maximum below, 18.

[0054] It is also possible to specifically tailor the catalyst performances by choosing the relative amounts of DE and NSDAE donor fixed on the catalysts. For example, when the DE / (NSDAE) molar ratio ranges from 0.8 to 2.5 polymerization activity and HR are tendentially at higher values with respect to stereospecificity. Conversely, if it is desired a very high stereospecificity level together with a good HR, it would be preferred to keep the DE / (NSDAE) molar ratio in the range from 2.6 to 6.0.

[0055] The solid catalyst component of the present disclosure is suited for direct use in polymerization together with the co-catalyst. Although pre-polymerization is not necessary, it can be performed by subjecting the solid catalyst component to pre-polymerization conditions in the presence of the olefin monomer and an Al-alkyl compound.12FE7752-WO-01

[0056] The terms pre-polymerization conditions means the complex of conditions in terms of temperature, monomer feeding and amount of reagents which allows to prepare a pre-polymerized catalyst component containing from 0.1 to 500 g of polymer per g of catalysts .

[0057] The co-catalyst used in the prepolymerization can be the same alkyl-Al compound (ii) previously described.

[0058] The prepolymerization can be carried out either in-line, i.e, in one of the reactors of a cascade polymerization process, or batchwise. In this latter process the final pre-polymerized catalyst is recovered, isolated and then used in a separate polymerization process.

[0059] In case of the batch pre-polymerization, it has been found particularly convenient using low amounts of alkyl-Al compound. In particular, said amount could be such as to have an Al compound / catalyst weight ratio from ranging from 0.001 to 10, preferably from 0.005 to 5 and more preferably from 0.005 to 1.5.

[0060] The pre-polymerization can be carried out with any a-olefins in particular selected from the group consisting of ethylene, propylene, butene- 1, 4-methyl-penyene-l, hexene- 1 and octene- 1.

[0061] The pre-polymerization step can be carried out at temperatures from 0° to 80°C preferably from 5° to 50°C in liquid or gas-phase. The batch pre-polymerization of the catalyst of the disclosure with ethylene in order to produce an amount of polymer ranging from 0.2 to 20 g per gram of catalyst component is particularly preferred.

[0062] An external donor selected from silicon compounds, ethers, esters, amines, heterocyclic compounds, ketones and 1,3-diethers of the general formula (I) previously reported can also be employed. However, use of an external donor in pre-polymerization is not strictly necessary.

[0063] The pre-polymerization can be carried out in liquid phase, (slurry or bulk) or in gasphase at temperatures generally ranging from -20 to 80°C preferably from 0°C to 75°C. Preferably, it is carried out in a liquid diluent in particular selected from liquid light hydrocarbons. Among them, pentane, hexane and heptane are preferred. In an alternative embodiment the pre-polymerization can be carried out in a more viscous medium in particular having a kinematic viscosity ranging from 5 to 100 cSt at 40°C. Such a medium can be either a pure substance or a homogeneous mixture of substances having different kinematic viscosity. Preferably, such a medium is an hydrocarbon medium and more preferably it has a kinematic viscosity ranging from 10 to 90 cStat40°C.13FE7752-WO-01

[0064] The olefin monomer to be pre-polymerized can be fed in a predetermined amount and in one step in the reactor before the pre-polymerization. In an alternative embodiment, the olefin monomer is continuously supplied to the reactor during polymerization at the desired rate.

[0065] The catalysts of the present disclosure are suited for use in any polymerization technology and especially for gas-phase polymerization. The gas-phase process can be carried out with any type of gas-phase reactor. Specifically, it can be carried out operating in one or more fluidized or mechanically agitated bed reactors. In the fluidized bed reactors the fluidization is obtained by a stream of inert fluidization gas the velocity of which is not higher than transport velocity. As a consequence the bed of fluidized particles can be found in a more or less confined zone of the reactor. In the mechanically agitated bed reactor the polymer bed is kept in place by the gas flow generated by the continuous blade movement the regulation of which also determine the height of the bed. The operating temperature may be between 50 and 85°C, preferably between 60 and 85°C, while the operating pressure can range from 0.5 and 8 MPa, preferably between 1 and 5 MPa more preferably between 1.0 and 3.0 MPa. Inert fluidization gases are also useful to dissipate the heat generated by the polymerization reaction and can be selected from nitrogen or preferably saturated light hydrocarbons such as propane, pentane, hexane or mixture thereof.

[0066] The polymer molecular weight can be controlled by using the proper amount of hydrogen or any other molecular weight regulator such as ZnEt2. If hydrogen is used, the hydrogen / propylene molar ratio can range from 0.0002 and 0.5, the propylene monomer being comprised from 20% to 100% by volume, preferably from 30 to 70% by volume, based on the total volume of the gases present in the reactor. The remaining portion of the feeding mixture is comprised of inert gases and one or more a-olefin comonomers, if any.

[0067] The catalyst of the present disclosure can be used in the gas-phase polymerization technology comprising at least two interconnected polymerization zones working under different conditions. The process is carried out in a first and second interconnected polymerization zone to which propylene and ethylene or propylene and alpha-olefins are fed in the presence of a catalyst system and from which the polymer produced is discharged. The growing polymer particles flow through the first of polymerization zones (riser) under fast fluidization conditions, leave said first polymerization zone and enter the second polymerization zone (downcomer) through which they flow in a densified form under the action of gravity, leave the second polymerization zone and are14FE7752-WO-01reintroduced into the first polymerization zone, thus establishing a circulation of polymer between the two polymerization zones.

[0068] The conditions of fast fluidization in the first polymerization zone can be established by feeding the monomers gas mixture below the point of reintroduction of the growing polymer into the first polymerization zone. The velocity of the transport gas into the first polymerization zone is higher than the transport velocity under the operating conditions and preferably between 2 and 15 m / s. In the second polymerization zone, where the polymer flows in densified form under the action of gravity, high values of density of the solid are reached which approach the bulk density of the polymer; a positive gain in pressure can thus be obtained along the direction of flow, so that it becomes possible to reintroduce the polymer into the first reaction zone without the help of mechanical means. In this way, a “loop” circulation is set up, which is defined by the balance of pressures between the two polymerization zones and by the head loss introduced into the system.

[0069] Also in this case, one or more inert gases, such as nitrogen or an aliphatic hydrocarbon, are maintained in the polymerization zones, in such quantities that the sum of the partial pressures of the inert gases is preferably between 5 and 80% of the total pressure of the gases. The operating temperature ranges from 50 and 85°C, preferably between 60 and 85°C, while the operating pressure ranges from 0.5 to 10 MPa, preferably between 1.5 and 6 MPa. Preferably, the catalyst components are fed to the first polymerization zone, at any point of said first polymerization zone. However, they can also be fed at any point of the second polymerization zone. The use of molecular weight regulator is carried out under the previously described conditions.

[0070] By the use of the means described in WO00 / 02929 it is possible to totally or partially prevent that the gas mixture present in the riser enters the downcomer; in particular, this is preferably obtained by introducing in the downer a gas and / or liquid mixture having a composition different from the gas mixture present in the riser. According to a particularly embodiment of the present disclosure, the introduction into the downcomer of the said gas and / or liquid mixture having a composition different from the gas mixture present in the riser is effective in preventing the latter mixture from entering the downcomer. Therefore, it is possible to obtain two interconnected polymerization zones having different monomer compositions and thus able to produce polymers with different properties.15FE7752-WO-01EXAMPLES

[0071] The following examples are given in order to better illustrate the disclosure without limiting it in any manner.CHARACTERIZATION

[0072] Determination of X.L2.5 g of polymer were dissolved in 250 ml of o-xylene under stirring at 135°C for 30 minutes, then the solution was cooled to 25°C and after 30 minutes the insoluble polymer was filtered. The resulting solution was evaporated in nitrogen flow and the residue was dried and weighed to determine the percentage of soluble polymer and then, by difference, the X.I. %.

[0073] Average Particle Size of the adduct and catalystsDetermined by a method based on the principle of the optical diffraction of monochromatic laser light with the "Malvern Instr. 2600" apparatus. The average size is given as D50 being defined as the value of the diameter such that 50% of the total volume of particles have a diameter lower than that value.

[0074] Bulk Density ASTM D 1895 / 96 Method A

[0075] Melt flow rate (MFR) determined according to ISO 1133 (230°C, 2.16 Kg)

[0076] Porosity and surface area with NitrogenPorosity and surface area with nitrogen: are determined according to the B.E.T. method (apparatus used SORPTOMATIC 1900 by Carlo Erba).

[0077] Porosity and surface area with mercury:The measure is carried out using a "Porosimeter 2000 Series" by Carlo Erba.The porosity is determined by absorption of mercury under pressure. For this determination use is made of a calibrated dilatometer (diameter 3 mm) CD3 (Carlo Erba) connected to a reservoir of mercury and to a high-vacuum pump (1 10-2 mbar). A weighed amount of sample is placed in the dilatometer. The apparatus is then placed under high vacuum (<0.1 mm Hg) and is maintained in these conditions for 20 minutes.

[0078] The dilatometer is then connected to the mercury reservoir and the mercury is allowed to flow slowly into the dilatomer until it reaches the level marked on the dilatometer at a height of 10 cm. The valve that connects the dilatometer to the vacuum pump is closed and then the mercury16FE7752-WO-01pressure is gradually increased with nitrogen up to 140 kg / cm2. Under the effect of the pressure, the mercury enters the pores and the level goes down according to the porosity of the material.

[0079] The porosity (cm3 / g), due to pores up to 1pm for catalysts (10pm for polymers), the pore distribution curve, and the average pore size are directly calculated from the integral pore distribution curve which is function of the volume reduction of the mercury and applied pressure values (all these data are provided and elaborated by the porosimeter associated computer which is equipped with a “MILESTONE 200 / 2.04” program by C. Erba.

[0080] General procedure for propylene polymerization testA 4 litre steel autoclave equipped with a stirrer, pressure gauge, thermometer, catalyst feeding system, monomer feeding lines and thermostatting jacket, was used. The reactor was charged with 0.008 gr. of solid catalyst component 0.36 g of TEAL, 3.21 of propylene, and the amount of hydrogen and external donor indicate in Table 1. The system was heated to 80°C over 10 min. under stirring, and maintained under these conditions for 60 min. At the end of the polymerization, the polymer was recovered by removing any unreacted monomers and was dried under vacuum..

[0081] Catalyst support preparation

[0082] In a vessel reactor equipped with a IKA RE 166 stirrer containing 182.8 g of anhydrous EtOH at -8°C were introduced under stirring 100 g of MgCh and 3.2 g of water. Once the addition of MgCh was completed, the temperature was raised up to 108°C and kept at this value for 20 hrs. After that, while keeping the temperature at 108°C, the melt was fed by volumetric pump set to 260 cm3 / min together with OB55 oil fed by volumetric pump set to 1100 cm3 / min, to an emulsification unit operating at 1500 rpm and producing an emulsion of the melt into the oil.

[0083] While melt and oil were fed in continuous, the mixture at about 108°C was continuously discharged into a vessel containing 5 liters of cold hexane which was kept under stirring and cooled so that the final temperature did not exceed 12°C. After 24 hours, the solid particles of the adduct recovered were then washed with hexane and dried at 40° C under vacuum, resulting to have a D50 diameter of 68.6pm. The adduct was then thermally dealcoholated in a fluidized bed under increasing temperature nitrogen flow until the content of EtOH reached a chemical composition of 50.2%wt EtOH and 1 ,4%wt H2O the remaining being MgCh.17FE7752-WO-01Example 1Preparation of final catalyst component

[0084] Into a 2.0 litre round bottom flask, equipped with mechanical stirrer, cooler and thermometer 1.01 of TiCk were introduced at room temperature under nitrogen atmosphere. After cooling at -5°C, while stirring, 50 g of microspheroidal catalyst support prepared as disclosed in the general procedure were introduced. The temperature was then raised from -5°C up to 40°C at a speed of 0.4°C / min. and an amount of diethyl succinate (DES) such as to have a Mg / DES molar ratio of 24 was added. The temperature was raised to 110°C and kept at this value for 50 min. After siphoning, fresh TiCk and an amount of 9,9-bis(methoxymethyl)fluorene (BMMF) such as to have a Mg / BMMF molar ratio of 12 were added. Then the temperature was raised to 100°C for 30min. The treatment with TiCk was repeated at 90°C for 15 min the solid was washed six times with anhydrous hexane (6 x 100 ml) at 60 °C.

[0085] The solid was finally dried under vacuum and analyzed. Catalyst composition and polymerization results are reported in table 1.Example 2

[0086] The same procedure disclosed in example 1 was carried out with the difference that diethyl glutarate (DEG) was used instead of DES. Catalyst composition and polymerization results are reported in table 1.Example 3

[0087] The same procedure disclosed in example 1 was carried out with the difference that diethyl malonate (DEM) was used instead of DES. Catalyst composition and polymerization results are reported in table 1.Comparative example 1.

[0088] The same procedure disclosed in example 1 was carried out with the difference that diethyl 2,3 -diisopropylsuccinate (DEIPS) was used instead of diethyl succinate (DES). Catalyst composition and polymerization results are reported in table 1.Example 4

[0089] The same procedure disclosed in example 1 was carried out with the difference that the Mg / DES molar ratio was 30 and Mg / BMMF molar ratio was 5. Catalyst composition and polymerization results are reported in table 2.Example 518FE7752-WO-01

[0090] The same procedure disclosed in example 4 was carried out with the difference that diethyl glutarate (DEG) was used instead of DES. Catalyst composition and polymerization results are reported in table 2.Example 6

[0091] The same procedure disclosed in example 1 was carried out with the difference that diethyl malonate (DEM) was used instead of DES. Catalyst composition and polymerization results are reported in table 2.Comparative example 2.

[0092] The same procedure disclosed in example 4 was carried out with the difference that diethyl 2,3-diisopropylsuccinate (DEIPS) was used instead of diethyl succinate (DES). Catalyst composition and polymerization results are reported in table 2.Table 119FE7752-WO-01Table 1 continuedTABLE 220FE7752-WO-01TABLE 2 continued21FE7752-WO-01

Claims

1. CLAIMSWhat is claimed is:

1. A catalyst component for the polymerization of olefins comprising Ti, Mg and at least two internal electron donor compounds one of which being selected from 1,3-diethers (DE) and the other being selected from non-substituted aliphatic acids (NSDAE), said catalyst component being characterized by the fact that the molar ratio ID / Ti is from 0.40 to 1.60, where ID is the total molar amount of (NSDAE) and (DE), and the molar ratio between (DE) and (NSDAE) ranges from 0.70 to 6.0.

2. The solid catalyst component according to claim 1 wherein (DE) is selected from the 1,3- diethers of formula (I)where R1and Rnare the same or different and are hydrogen or linear or branched Ci-Cis hydrocarbon groups which can also form one or more cyclic structures; R111groups, equal or different from each other, are hydrogen or Ci-Cis hydrocarbon groups; RIVgroups equal or different from each other, have the same meaning of R111except that they cannot be hydrogen; each of R1to RIVgroups can contain heteroatoms selected from halogens, N, O, S and Si.

3. The solid catalyst component according to claim 2 where RIVis a Ci-Ce alkyl group and preferably methyl, while the R111radicals are preferably hydrogen.

4. The solid catalyst component according to any of preceding claims wherein R1and Rnare, independently, hydrogen, methyl, ethyl, propyl, isopropyl, butyl, isobutyl, tert-butyl, isopentyl, 2-ethylhexyl, cyclopentyl, cyclohexyl, methylcyclohexyl, phenyl or benzyl.

5. The catalyst component according to any of preceding claims wherein R1is a linear or branched primary alkyl group containing at least three carbon atoms such as butyl, isobutyl,22FE7752-WO-01isopentyl, 2-ethylhexyl and Rnis a secondary alkyl or cycloalkyl group such as isopropyl, cyclopentyl and cyclohexyl.

6. The solid catalyst component according to any of the claims 1 -2, wherein DE is selected from compounds of formula (III):where the R111and RIVradicals have the same meaning defined in formula (I), RVIradicals equal or different are hydrogen; halogens, preferably Cl and F; C1-C20 alkyl radicals, linear or branched; C3-C20 cycloalkyl, C6-C20 aryl, C7-C20 alkylaryl and C7-C20 aralkyl radicals, optionally containing one or more heteroatoms selected from the group consisting of N, O, S, P, Si and halogens, in particular Cl and F, as substitutes for carbon or hydrogen atoms, or both.

7. The component according to any of the preceding claims wherein (NSDAE) is selected from alkyl esters of non-substituted dicarboxylic aliphatic acids, saturated or unsaturated, having from 3 to 8 carbon atoms.

8. The catalyst component according to claim 7 wherein (NSDAE) is selected from diester of formula (IV) R00C-(CH2)n-C00R in which n is an integer from 1 to 4 and the R groups, equal to or different from each other, are C1-C10 alkyl groups.

9. The catalyst according to claim 8 in which R is a Ci-Ce linear or branched alkyl, preferably ethyl or isobutyl and which n is from 1 to 3.

10. The catalyst component according to any of the preceding claims wherein the molar ratio between the ID (NSDAE+DE) and the Ti atoms in the final solid catalyst component ranges from 0.5:1 to 1.5:1 and more preferably from 0.6:1 to 1.3:1.23FE7752-WO-0111. The solid catalyst component according to any of the preceding claims wherein the molar ratio between the Mg atoms and the ID in the final solid catalyst component ranges from 4.0:1 to 16.0:1 and more preferably from 5.0:1 to 15.0:1.

12. The catalyst component according to any of the preceding claims wherein the molar ratio between (DE) and (NSDAE) is ranges from 0.90 to 5.50, preferably from 1.0 to 5.0, more preferably in the range 1.2 to 4.8.

13. The solid catalyst component according to claim 1 wherein the an average particle size D50 ranges from 15 to 100 pm more preferably from 30 to 90 pm and especially from 40 to 80 pm.

14. A catalyst system for the polymerization of olefins CH2=CHR, in which R is hydrogen or a hydrocarbyl radical with 1-12 carbon atoms, comprising the product of the reaction between: (i) the solid catalyst component according to any one of the preceding claims, (ii) an alkylaluminum compound and optionally(iii) an external electron donor compound.

15. A process for the polymerization of olefins CH2=CHR, wherein R is hydrogen or a C1-C12 hydrocarbyl group, carried out in the presence of the catalyst system according to claim 14.24FE7752-WO-01

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