EP4630463A1

EP4630463A1 - Catalyst component

Info

Publication number: EP4630463A1
Application number: EP23814493.5A
Authority: EP
Inventors: Michel Clarembeau; Atanas Tomov; George Johan Peter Britovsek
Original assignee: Ineos Europe AG
Current assignee: Ineos Europe AG
Priority date: 2022-12-09
Filing date: 2023-11-30
Publication date: 2025-10-15
Also published as: JP2025538763A; WO2024120970A1; CN120303311A

Abstract

This invention relates to components useful in propylene polymerization catalysts, and in particular provides a solid, hydrocarbon-insoluble, catalyst component containing magnesium, titanium, and halogen and further comprising a modifier compound with a structure (1), wherein : - R¹ is selected from H aryl or alkyl groups having 1 to 10 carbon atoms, - R² is selected from alkyl groups having 1 to 10 carbon atoms, - R³ to R⁶ are each independently selected from H, alkylaryl, aryl or alkyl groups having 1 to 10 carbon atoms and halogens, but with the proviso that at least one of R⁴ and R⁵ is H, - any alkylaryl, aryl or alkyl groups optionally comprising one or more heteroatoms and/or optionally wherein R³and R⁴or R⁵ and R⁶ are joined to form a cyclic group.

Description

CATALYST COMPONENT

This invention relates to components useful in catalysts, and particularly relates to modifier components used in combination with magnesium-containing supported titanium- containing catalyst components.

Use of solid, transition metal-based, olefin polymerization catalyst components is well known in the art, including such solid components supported on a metal oxide, halide or other salt such as widely described magnesium-containing, titanium halide-based catalyst components. Although many polymerization and copolymerization processes and catalyst systems have been described for polymerizing or copolymerizing alpha-olefins, it is advantageous to tailor a process and catalyst system to obtain a specific set of properties of a resulting polymer or copolymer product. For example, in certain applications, a combination of high activity, good morphology, desired particle size distribution, acceptable bulk density, and the like, are required together with polymer characteristics such as stereospecificity, molecular weight distribution, and the like.

Typically, supported catalyst components useful for polymerizing propylene and higher alpha-olefins as well as for polymerizing propylene and higher olefins with minor amounts of ethylene and other alpha-olefins contain an electron donor component as an internal modifier. Such an internal modifier is an integral part of the solid supported component and is distinguished from any external electron donor component, which together with an aluminium alkyl component, may comprise the catalyst system. Typically, co-catalyst, such as aluminium alkyl, and any external electron donor are combined with the solid catalyst component, either shortly before the combination is contacted with an olefin monomer or in the presence of olefin monomer.

Selection of the internal modifier and other electron donor components can affect catalyst performance and the resulting polymer formed. A large number of organic electron donors have been described as useful in preparation of the stereospecific supported catalyst components including organic compounds containing oxygen, nitrogen, sulphur, and/or phosphorus. Such compounds include organic acids, organic acid anhydrides, organic acid esters, alcohols, ethers, aldehydes, ketones, amines, amine oxides, amides, thiols, various phosphorus acid esters and amides, and the like. Mixtures of organic electron donors have been described as useful in incorporating into supported catalyst components. Specific examples of organic electron donors typically used as internal modifiers include dicarboxylate esters, such as alkyl phthalates, succinate esters and other bidentate donors, such as diethers.

It is also known that, in addition to a co-catalyst, the external donor components of the catalyst can include several components. WO 2005/30815 and WO 2009/85649, for example, describe propylene polymerization catalysts which, in addition to one or more aluminium containing co-catalysts; include a combination of external donors, and in particular at least one alkoxysilane, which is referred to as a “selectivity control agent” (SCA) and at least one aliphatic or cycloaliphatic mono- or poly-carboxylic acids; or ester derivative thereof, which is referred to as an “activity limiting agent” (ALA).

Further, numerous individual processes or process steps have been disclosed to produce improved supported, magnesium-containing, titanium-containing, electron donor- containing olefin polymerization or copolymerization catalysts. For example, US 4866022 discloses a method for forming an advantageous alpha-olefin polymerization or copolymerization catalyst or catalyst component which involves a specific sequence of individual process steps. US 4540679, discloses a process for the preparation of a magnesium hydrocarbyl carbonate by reacting a suspension of a magnesium alcoholate in an alcohol with carbon dioxide and reacting the magnesium hydrocarbyl carbonate with a transition metal component. US 4612299, discloses a process for the preparation of a magnesium carboxylate by reacting a solution of a hydrocarbyl magnesium compound with carbon dioxide to precipitate a magnesium carboxylate and reacting the magnesium carboxylate with a transition metal component.

Particular uses of the polymers which can be produced depend upon the physical properties of the polymer, such as molecular weight, viscosity, stiffness, flexural modulus, and polydispersity index (molecular weight distribution (M_w/M_n)). In addition, polymer or copolymer morphology typically depends upon catalyst morphology.

The present invention relates to catalyst components and catalysts and in particular comprising a new modifier component.

Thus, in a first aspect the present invention provides a solid, hydrocarbon-insoluble, catalyst component containing magnesium, titanium, and halogen and further comprising a modifier compound with a structure (1):

wherein

R¹ is selected from H, aryl or alkyl groups having 1 to 10 carbon atoms,

R² is selected from alkyl groups having 1 to 10 carbon atoms,

R³ to R⁶ are each independently selected from H, alkylaryl, aryl or alkyl groups having 1 to 10 carbon atoms and halogens, but with the proviso that at least one of R⁴ and R⁵ is H any alkylaryl, aryl or alkyl groups optionally comprising one or more heteroatoms and/or optionally wherein R³ and R⁴ or R⁵ and R⁶ are joined to form a cyclic group.

The catalyst component is particularly useful, in conjunction with a co-catalyst, as a catalyst for the polymerization of olefins.

Thus, in a second aspect, the present invention also provides a catalyst useful in polymerizing olefins, said catalyst comprising:

(i) a solid, hydrocarbon-insoluble, catalyst component containing magnesium, titanium, and halogen and further comprising a modifier compound with a structure (1): wherein

R¹ is selected from H, aryl or alkyl groups having 1 to 10 carbon atoms,

R² is selected from alkyl groups having 1 to 10 carbon atoms,

R³ to R⁶ are each independently selected from H, alkylaryl, aryl or alkyl groups having 1 to 10 carbon atoms and halogens, but with the proviso that at least one of R⁴ and R⁵ is H, any alkylaryl, aryl or alkyl groups optionally comprising one or more heteroatoms and/or optionally wherein R³ and R⁴ or R⁵ and R⁶ are joined to form a cyclic group; and

(ii) at least one co-catalyst component.

For avoidance of doubt, the modifier is, and may also be considered as, an electron donor compound. The modifier as claimed may be used as an external electron donor in the first and second aspects of the present invention, but in preferred embodiments is used as an internal electron donor or, specifically, an “internal modifier”.

(As used herein the term “modifier” is used as shorthand to refer to the modifier compound of structure (1), and the terms “modifier” and “modifier compound” may be used interchangeably. The term “modifier” is used in the present invention to provide a clear distinction in terminology for the modifier of structure (1) from other electron donors which may be present in any aspect or embodiment.)

The terms “internal” and “external” as used in this context are well understood in the art. In general, and as used herein, the term “internal” when used in reference to a modifier (or other electron donor) refers to a compound which is an integral part of the solid supported catalyst component. Generally, this is achieved by adding the internal modifier (or other electron donor) during the catalyst preparation. In contrast, the term “external” when used in reference to a modifier (or other electron donor) refers to a compound which is combined with the other parts of solid catalyst component either shortly before the combination is contacted with an olefin monomer or is combined with the other parts of the solid catalyst component in the presence of olefin monomer e.g. in a reactor. In the present invention:

R¹ is selected from H (hydrogen), aryl or alkyl groups having 1 to 10 carbon atoms,

R² is selected from alkyl groups having 1 to 10 carbon atoms, and

R³ to R⁶ are each independently selected from H (hydrogen), alkylaryl, aryl or alkyl groups having 1 to 10 carbon atoms and halogens, but with the proviso that at least one of R⁴ and R⁵ is H.

Any alkylaryl, aryl or alkyl groups present may optionally comprise one or more heteroatoms. Optionally R³ and R⁴ may be joined to form a cyclic group. Optionally R’ and R⁶ may be joined to form a cyclic group.

R¹ is selected from hydrogen, aryl or alkyl groups having 1 to 10 carbon atoms. It is preferred that R¹ does not comprise any heteroatoms. It is also preferred that R¹ is not joined to any of R² to R⁶ to form a cyclic group (i.e. is not joined to the other groups other than as shown in structure (1)). R¹ is preferably selected from hydrogen, aryl or alkyl groups having 1 to 6 carbon atoms. Where R¹ is an aryl group it is preferably a phenyl group. R¹ is more preferably selected from hydrogen and alkyl groups having 1 to 6 carbon atoms. Most preferably, R¹ is selected from hydrogen, methyl, ethyl and propyl, such as selected from hydrogen and methyl. R¹ being hydrogen is most preferred.

R² is selected from alkyl groups having 1 to 10 carbon atoms. It is preferred that R² does not comprise any heteroatoms. It is also preferred that R² is not joined to any of R¹ and R³ to R⁶ to form a cyclic group (i.e. is not joined to the other groups other than as shown in structure (1). R² is preferably selected from alkyl groups having 1 to 6 carbon atoms. More preferably R² is selected from methyl, ethyl, propyl and butyl, with methyl, ethyl and butyl being most preferred.

R³ to R⁶ are each independently selected from hydrogen, alkylaryl, aryl or alkyl groups having 1 to 10 carbon atoms and halogens, with the proviso that at least one of R⁴ and R⁵ is H. It is preferred that any of R³ to R⁶ which are alkylaryl, aryl or alkyl groups having 1 to 10 carbon atoms do not comprise heteroatoms, (i.e. where R³ to R⁶ are not themselves halogen then they do not comprise heteroatoms.) Optionally, R³ and R⁴ may be joined to form a cyclic group. Optionally, R⁵ and R⁶ may be joined to form a cyclic group. (It should be noted that since at least one of R⁴ and R⁵ is H, then if R³ and R⁴ are joined form a cyclic group then R⁵ must be H, and R⁵ and R⁶ cannot be joined to form a cyclic group in the same structure, and vice versa.) In a first embodiment, R³ to R⁶ are each hydrogen. In three particularly preferred structures according to this embodiment, R¹ is also hydrogen, and R² is an alkyl selected from methyl, ethyl or butyl respectively. In a further preferred structure according to this embodiment R¹ and R² are both methyl. In a further preferred structure according to this embodiment R¹ is phenyl and R² is methyl.

In a second embodiment, at least one of R³ to R⁶ is a halogen. In this embodiment preferably R⁵ is a halogen, and most preferably is bromine. (And in this case it will be apparent that R⁴ must be H.) In preferred structures, R⁵ is a halogen, and most preferably is bromine, whilst each of R³, R⁴ and R⁶ are hydrogen. Most preferably, R¹ is hydrogen, R² is methyl, R³, R⁴ and R⁶ are each hydrogen, and R⁵ is a halogen, and, in a particularly preferred structure according to this embodiment, most preferably is bromine.

In a third embodiment, at least one of R³ to R⁶ is an alkyl, and preferably having 1 to 6 carbon atoms. In this embodiment it may also be that at least one of R³ to R⁵ may be a halogen. However, this is not preferred. Preferably at least two of R³ to R⁶ are hydrogen i.e. a maximum of two of R³ to R⁶ are alkyl. In one preferred option at least one of R³ and R⁵ is an alkyl. In a particularly preferred structure according to this option R¹ is hydrogen, R² is methyl, R³ and R⁵ are tert-butyl, and R⁴ and R⁶ are each hydrogen. In another preferred option at least R⁶ is an alkyl. In a particularly preferred structure according to this option R¹ is hydrogen, R² is butyl, R³ to R⁵ are each hydrogen and R⁶ is methyl.

As already noted, optionally R³ and R⁴ or R⁵ and R⁶ may be joined to form a cyclic group. In embodiments, a number of preferred options for which are disclosed above, R³ and R⁴ are not joined to form a cyclic group and R⁵ and R⁶ are not joined to form a cyclic group. In these embodiments it is more generally preferred that none of R¹ to R⁶ are joined to any others of R¹ to R⁶ to form cyclic groups (i.e. no cyclic groups are present other than the aromatic ring of structure (1)).

Where a cyclic group (other than the aromatic ring of structure (1)) is present then most preferably R³ and R⁴ are linked to form said cyclic group. In this case R⁵ is H. It is also preferred in this case that none of R¹, R²and R⁶ are joined to any others of R¹, R² and R⁶ or to the group formed by R³ and R⁴ (i.e. no further cyclic groups are present).

In this embodiment, a particularly preferred structure is the following structure (2):

wherein

R¹, R² and R⁶ are as already defined,

R⁵ is H, and

R⁷ to R¹⁰ are each independently selected from H, alkylaryl, aryl or alkyl groups having 1 to 6 carbon atoms and halogens, the alkylaryl, aryl and alkyl groups optionally comprising one or more heteroatoms. R⁵, R² and R⁶ are as preferably already defined for structure (1).

R⁷ to R¹⁰ are each independently selected from hydrogen, alkylaryl, aryl or alkyl groups having 1 to 6 carbon atoms and halogens, the alkylaryl, aryl and alkyl groups optionally comprising one or more heteroatoms. Preferably R⁷ to R¹⁰ do not comprise heteroatoms (and most preferably none of R¹, R² and R⁶to R¹⁰ comprise any heteroatoms).

It is also preferred in this structure (2) that none of R¹, R² and R⁶ to R¹⁰ are joined to any others of R¹, R² and R⁶ to R¹⁰. (i.e. no further cyclic groups are present.)

Preferably R⁷ to R¹⁰ are each independently selected from hydrogen and alkyl groups having 1 to 6 carbon atoms, more preferably selected from hydrogen, methyl, ethyl and propyl. R⁷to R¹⁰ each being hydrogen is most preferred.

In a preferred structure according to structure (2), R² is ethyl, and R¹ and R⁵ to R¹⁰ are all hydrogen.

More generally in the present invention, and although not preferred, any of the alkylaryl, aryl or alkyl groups may be substituted with heteroatoms. Examples include oxygen, sulphur, nitrogen, phosphorus, silicon or halogens. For example, an alkyl group used in this invention may be substituted with a nitrogen in the form of an amine group, with nitrogen and oxygen in the form of an amide group, or with chloro, bromo or silyl groups. Cyclic alkyl or aryl structures may contain hetero atoms such as oxygen, sulphur, nitrogen, silicon, and phosphorus.

As already noted, other than where one or more of R³ to R⁶ is a halogen, preferably none of R¹ to R⁶ in structure (1) or R¹, R² or R⁶ to R¹⁰ in structure (2) comprise heteroatoms i.e. they comprise solely H atoms or solely C and H atoms.

In preferred embodiments the modifier, particularly one of the preferred modifiers described above, is present in the catalyst component as an internal modifier.

It should also be noted that mixtures of modifier compounds described by the structure (1) may be used as well as mixtures of such compounds with other donor compounds known in the art. Examples of this are described further below. (For avoidance of doubt, reference herein to compounds of structure (1) includes also the “subset” of such compounds which are also described by the structure (2) even if said structure is not referred to directly. This is because the compounds of structure (2) are also compounds according to structure (1).)

The solid, hydrocarbon-insoluble, catalyst component generally comprises titanium compounds supported on magnesium-containing compounds, in combination with the modifier compound. In preferred embodiments, where the modifier is an internal modifier, then the supported titanium-containing olefin polymerization catalyst component typically is formed by reacting a titanium compound, a modifier compound and a magnesium- containing compound. Optionally, such supported titanium-containing reaction product may be further treated or modified by further chemical treatment.

Suitable magnesium-containing compounds include magnesium halides; a reaction product of a magnesium halide such as magnesium chloride or magnesium bromide with an organic compound, such as an alcohol or an organic acid ester, or with an organometallic compound of metals of Groups I-III; magnesium alcoholates; or magnesium alkyls.

A particularly preferred titanium compound for use in such steps is TiCl₄- although numerous other species, such as other titanium (IV) halides or titanium alcoholates are also known to be suitable.

The present invention is not limited to a catalyst component prepared by any specific method of preparation. For example, the catalyst component comprising an internal modifier may be prepared by reacting the magnesium and titanium compounds and the modifier compound in any suitable order. For example, the catalyst components may be prepared by reacting the magnesium and titanium compounds first, and then incorporation of the modifier compound. Alternatively, the modifier may be incorporated prior to the titanium compound, during the addition of the titanium compound, or (in multiple steps) in a combination thereof.

Generally, the aforesaid modifier compounds and titanium compounds may be contacted with solid particles of a magnesium compound in the presence of an inert hydrocarbon or halogenated diluent, although other suitable techniques can be employed. Suitable diluents are substantially inert to the components employed and are liquid at the temperature and pressure employed.

Most typically, a solution or solutions of titanium tetrachloride and the modifier compound is/are contacted with a magnesium-containing material, for example by addition to a slurry of magnesium containing particles in a suitable hydrocarbon. Such magnesium- containing material typically is in the form of discrete particles and may contain other materials such as transition metals and organic compounds. Also, a mixture of magnesium chloride, titanium tetrachloride and the modifier may be formed into an active catalyst component by ball-milling.

In a preferred method, however, a slurry of a magnesium containing material is first contacted with a solution of the modifier, typically with stirring. The obtained solution is then be treated with a suitable titanium containing species. Several steps may be applied for addition of the internal donor or the titanium, or both.

In one particularly advantageous procedure, magnesium chloride-based support particles suspended in a liquid hydrocarbon diluent, such as toluene, are first contacted with titanium tetrachloride, and then with a modifier compound, these two contacting steps being repeated one or more times, before a final contacting step with titanium tetrachloride (i.e. without the subsequent addition step of further modifier). The diluent used may be decanted between steps and fresh diluent added prior to the next step. After the final step the diluent is removed, and the product is washed one or more times with a liquid hydrocarbon, such as heptane, and then dried. The conditions in such steps are known in the art. The steps are usually performed at elevated temperatures, typically from 75 to 135 °C, and at normal or slightly elevated pressures from 1 to 3 bar. Typical individual treatment times for each step may vary from several minutes to several hours, usually from 0.25 to 3 hours.

As a result of the preparation steps, there is obtained a solid reaction product suitable for use as a catalyst or catalyst component. Prior to such use, it is desirable to remove incompletely reacted starting materials from the solid reaction product. This is conveniently accomplished by washing the solid, after separation from any preparative diluent, with a suitable solvent, such as a liquid hydrocarbon or chlorocarbon, preferably within a short time after completion of the preparative reaction because prolonged contact between the catalyst component and unreacted starting materials may adversely affect catalyst component performance.

Although not required, the final solid reaction product may be washed with an inert liquid hydrocarbon or halogenated hydrocarbon before contact with a Lewis acid. If such a wash is conducted, it is preferred to substantially remove the inert liquid prior to contacting the washed solid with Lewis acid.

In a typical catalyst component in the present invention, the magnesium to titanium molar ratio is at least 1 :1, and preferably up to 20: 1. Greater amounts of magnesium may be employed without adversely affecting catalyst component performance, but typically there is no need to exceed a magnesium to titanium ratio of 20: 1. More preferably, the magnesium to titanium ratio ranges from 2:1 to 20:1, such as from 5: 1 to 20:1.

The catalyst component of the present invention generally comprises from 1 to 6 weight percent titanium, from 10 to 25 weight percent magnesium, and from 45 to 65 weight percent halogen. Preferably, the catalyst component comprises from 2 to 4 weight percent titanium, from 15 to 21 weight percent magnesium and from 55 to 65 weight percent chlorine.

The modifier component, when used as an internal modifier, is typically incorporated into the solid catalyst component in a molar ratio of modifier to titanium at least 0.1 :1 and/or up to 10:1. The molar ratio is preferably at least 0.2: 1, and more preferably at least 0.4:1. The molar ratio is preferably up to 5:1, such as up to 2:1. A molar ratio of modifier to titanium in the range of 0.4:1 to 1.2:1 is most preferred. As already noted, in an embodiment of the present invention, mixtures of electron donors may be used. This includes mixtures of two or more modifier compounds described by the structure (1) as well as mixtures of such compounds with other electron donor compounds known in the art.

For example, where a modifier of structure (1) is used as an internal modifier (internal electron donor), then the modifier may be used as a component of an internal donor mixture. Preferably, in these embodiments the internal donor mixture is a mixture of at least one compound of the structure (1) with at least one other electron donor compound known in the art (hereinafter referred to as an “additional internal donor”).

In one embodiment the additional internal donor may be a dialkylphthalate. For example, the additional internal donor may be a dialkylphthalate wherein each alkyl group may be the same or different and contains from 3 to 5 carbon atoms, preferably a dibutylphthalate and more preferably is di-n- butylphthalate or di-i-butylphthalate. Alternatively, the additional internal donor may be a dialkylphthalate wherein each alkyl group may be the same or different and each contains at least 6 carbon atoms, preferably up to 10 atoms. Particular dialkylphthalates which are suitable include dihexylphthalate and dioctylphthalate.

In an alternative, the additional internal donor may be a dicycloaliphatic ester of an aromatic dicarboxylic acid wherein each cycloaliphatic moiety may be the same or different and each contains from 5 to 7 carbon atoms, and preferably contains 6 carbon atoms. Preferably the ester is a dicycloaliphatic diester of an ortho aromatic dicarboxylic acid. Particular di cycloaliphatic esters that are suitable include dicyclopentylphthalate, dicyclohexylphthalate, and di-(methylcyclopentyl)-phthalate.

In another option, the additional internal donor may be an alkyl-arylalkyl phthalate wherein the alkyl moiety contains 2 to 10, preferably 3 to 6, carbon atoms, and the arylalkyl moiety contains from 7 carbon atoms up to 10, preferably up to 8, carbon atoms. Particularly, alkyl-arylalkyl phthalates suitable include benzyl n-butyl phthalate and benzyl i-butyl phthalate.

Also, the additional internal donor may be an alkyl ester of an aliphatic monocarboxylic acid wherein carboxylic acid moiety contains 2 to 20, preferably 3 to 6, carbon atoms and the alkyl moiety contains from 1 to 3 carbon atoms. Preferably the additional internal donor is an alkyl ester of an aliphatic monocarboxylic acid. Particular alkyl esters that are suitable include methyl valerate, ethyl pivalate, methyl pivalate, methyl butyrate, and ethyl propionate.

In another alternative, such additional internal donor also may be an alkyl ester of an aromatic monocarboxylic acid wherein the monocarboxylic acid moiety contains from 6 to 8 carbon atoms and the alkyl moiety contains from 1 to 3 carbon atoms. Particular alkyl esters that are suitable in this case include methyl toluate, ethyl toluate, methyl benzoate, ethyl benzoate and propyl benzoate.

In a yet further alternative, the additional internal donor also may be a 1,3 -di ether, and particularly a 2,2-di-substituted-1,3-diether. Preferred examples include 2-isopropyl-2- isobuty 1-1, 3 -dimethoxypropane, 2,2-diisobutyl-1,3-dimethoxypropane, 2-isopropyl-2- isopentyl- 1 ,3-dimethoxypropane, 2,2-dicyclohexyl- 1 ,3 -dimethoxypropane, 2,2- bis(cyclohexylmethyl)-1,3-dimethoxypropane, and 9,9-bis(methoxymethyl)fluorene. Among these, 2-isopropyl-2-iso butyl- 1,3 -dimethoxypropane, 2-isopropyl-2-isopentyI-1,3- dimethoxypropane, and 9,9-bis(methoxymethyl)fluorene are preferable.

The mole ratio of the additional internal donor to the (internal) modifier in all options above may, for example, range from 5:95 to 95:5.

The catalyst or catalyst component of this invention may be used in the polymerization or copolymerization of alpha olefins. Pre-polymerization or encapsulation of the catalyst or catalyst component may be carried out prior to being used in the polymerization. A particularly useful pre-polymerization procedure is described in US 4579836.

Typically, the catalyst component of the present invention is used for polymerization in conjunction with a cocatalyst component. The cocatalyst component may be a Group II or III metal alkyl. Useful Group II and III A metal alkyls are compounds of the formula MR_m wherein M is a Group II or III metal, each R is independently an alkyl radical of 1 to 20 carbon atoms, and m corresponds to the valence of M. Examples of useful metals, M, include magnesium, calcium, zinc, cadmium, aluminium, and gallium. Examples of suitable alkyl radicals, R, include methyl, ethyl, butyl, hexyl, decyl, tetradecyl, and eicosyl. From the standpoint of catalyst or catalyst component performance, preferred Group II and IIIA metal alkyls are those of magnesium, zinc, and aluminium wherein the alkyl radicals contain 1 to 12 carbon atoms. Specific examples of such compounds include Mg(CH₃)₂, Mg(C₂H₅)₂, Mg(C₂H₅)(C₄H₉), Mg(C₄H₉)₂, Mg(C₆H₁₃)₂, Mg(C₁₂H₂₅)₂, Zn(CH₃)₂, Zn(C₂H₅)₂, Zn(C₄H₉)₂, Zn(C₄H₉)(C₈H₁₇), Zn(C₆H₁₃)₂, Zn(C₆H₁₃)₃, and AI(C₁₂H₂₅)₃. A magnesium, zinc, or aluminium alkyl containing 1 to 6 carbon atoms per alkyl radical may preferably be used.

Aluminium alkyls are most preferred as co-catalyst and even more preferably trialkylaluminiums containing 1 to 6 carbon atoms per alkyl radical. Particularly triethylaluminium and triisobutylaluminium or a combination thereof can be used.

If desired, however, metal alkyls having one or more halogen or hydride groups can be employed, such as ethylaluminium dichloride, diethylaluminium chloride, and the like.

The catalyst for the polymerization or copolymerization of alpha olefins may be formed by combining the supported titanium-containing catalyst component of the first aspect of the present invention and a co-catalyst component, preferably an alkyl aluminium compound.

Typically, useful aluminium-to-titanium molar ratios in such catalyst systems are 10:1 to 2000:1 and preferably 50:1 to 1500:1.

Typically, the catalyst component of the present invention is used for polymerization in conjunction with a co-catalyst and also with one or more further electron donor compounds. In particular, in one embodiment of the present invention modifiers of structure (1) may be used as both internal and external electron donors for the catalyst, either alone or in combination with other suitable electron donors.

In preferred embodiments, however, the modifier is used as an internal modifier (or internal electron donor), optionally as part of an internal donor mixture as described, and is further used in conjunction with one or more other external electron donors.

Typical aluminium-to-external electron donor molar ratios in such catalyst systems are 2 to 60.

A preferred external electron donor is a silane. Typical aluminium- to-silane compound molar ratios in such catalyst systems are 3 to 50. Preferable silanes include alkyl-, aryl-, and/or alkoxy-substituted silanes containing hydrocarbon moieties with 1 to 20 carbon atoms. Especially preferred are silanes having a formula: SiY₄, wherein each Y group is the same or different and is an alkyl or alkoxy group containing 1 to 20 carbon atoms. Preferred silanes include isobutyltrimethoxysilane, diisobutyldimethoxysilane, diisopropyldimethoxysilane, n- propyltriethoxysilane, isobutylmethyldimethoxysilane, isobutylisopropyldimethoxysilane, dicyclopentyldimethoxysilane, tetraethylorthosilicate, dicyclohexyldimethoxysilane, diphenyldimethoxysilane, di-t- butyldimethoxysilane, and t- butyltrimethoxysilane.

Other compounds useful as external electron donors, either as an alternative to or in addition to one or more silanes, are organic compounds containing oxygen, nitrogen, sulphur, and/or phosphorus. Such compounds include organic acids, organic acid anhydrides, organic acid esters, alcohols, ethers, aldehydes, ketones, amines, amine oxides, amides, thiols, various phosphorus acid esters and amides, and the like. Mixtures of external electron donors may be used.

Particular organic acids and esters are benzoic acid, halobenzoic acids, phthalic acid, isophthalic acid, terephthalic acid, and the alkyl esters thereof wherein the alkyl group contains 1 to 6 carbon atoms such as methyl chlorobenzoates, butyl benzoate, isobutyl) benzoate, methyl anisate, ethyl anisate, methyl p-toluate, hexylbenzoate, and cyclohexyl-benzoate, and diisobutyl phthalate as these give good results in terms of activity and stereospecificity and are convenient to use.

The catalyst or catalyst component of this invention is useful in the stereospecific polymerization or copolymerization of alpha-olefins containing 3 or more carbon atoms such as propylene, butene-1, pentene-1, 4-methylpentene-1 and hexene-1, as well as mixtures thereof and mixtures thereof with ethylene.

Thus, in a third aspect, the present invention provides a process to polymerize propylene or a mixture of propylene and ethylene or a C₄-C₅ alpha-olefin, which process comprises using a catalyst according to the second aspect.

The catalyst or catalyst component of this invention is particularly effective in the stereospecific polymerization or copolymerization of propylene or mixtures thereof with up to 30 mole percent ethylene or a higher alpha-olefin. Highly crystalline poly alpha-olefin homopolymers or copolymers can be prepared by contacting at least one alpha-olefin with the catalyst or catalyst components under polymerization or copolymerization conditions. Such conditions include polymerization or copolymerization temperature and time, pressure(s) of the monomer(s), avoidance of contamination of catalyst, choice of polymerization or copolymerization medium in slurry processes, the use of additives to control homopolymer or copolymer molecular weights, and other conditions well known to persons skilled in the art. Slurry-, bulk-, and vapor-phase polymerization or copolymerization processes are contemplated herein. The amount of the catalyst or catalyst component to be used varies depending on choice of polymerization or copolymerization technique, reactor size, monomer to be polymerized or copolymerized, and other factors known to persons of skill in the art, and can be determined on the basis of the examples appearing hereinafter. Typically, the catalyst or catalyst component of this invention is used in amounts ranging from 0.2 to 0.02 milligrams of catalyst to gram of polymer or copolymer produced.

Irrespective of the polymerization or copolymerization process employed, polymerization or copolymerization should be carried out at temperatures sufficiently high to ensure reasonable polymerization or copolymerization rates and avoid unduly long reactor residence times, but not so high as to result in the production of unreasonably high levels of stereo-random products due to excessively rapid polymerization or copolymerization rates. Generally, temperatures range from 0° to 120°C with a range of from 20°C to 95°C being preferred from the standpoint of attaining good catalyst performance and high production rates. More preferably, polymerization is carried out at temperatures ranging from 50°C to 80°C.

Olefin polymerization or copolymerization may be carried out at monomer pressures of atmospheric or above. Generally, monomer pressures range from 140 to 4100 kPa, although in vapor phase polymerizations or copolymerizations monomer pressures should not be below the vapor pressure at the polymerization or copolymerization temperature of the alpha-olefin to be polymerized or copolymerized.

The polymerization or copolymerization time will generally range from ½ to several hours in batch processes with corresponding average residence times in continuous processes. Polymerization or copolymerization times ranging from 1 to 4 hours are typical in autoclave-type reactions. In slurry processes, the polymerization or copolymerization time can be regulated as desired. Polymerization or copolymerization times ranging from ½ to several hours are generally sufficient in continuous slurry processes.

Diluents suitable for use in slurry polymerization or copolymerization processes include alkanes and cycloalkanes such as pentane, hexane, heptane, n- octane, isooctane, cyclohexane, and methylcyclohexane; alkylaromatics such as toluene, xylene, ethylbenzene, isopropylbenzene, ethyl toluene, n-propyl-benzene, diethylbenzenes, and mono- and dialkylnaphthalenes; halogenated and hydrogenated aromatics such as chlorobenzene. Chloronaphthalene, ortho- dichlorobenzene, tetrahydro-naphthalene, decahydronaphthalene; high molecular weight liquid paraffins or mixtures thereof, and other well-known diluents. It often is desirable to purify the polymerization or copolymerization medium prior to use, such as by distillation, percolation through molecular sieves, contacting with a compound such as an alkylaluminium compound capable of removing trace impurities, or by other suitable means.

Examples of gas-phase polymerization or copolymerization processes in which the catalyst or catalyst component of this invention may be used include both stirred bed reactors and fluidized bed reactor systems and are described in US 3957448; US 3965083; US 3971786; US 3970611; US 4129701; US 4101289; US 3652527; and US 4003712. Typical gas phase olefin polymerization or copolymerization reactor systems comprise at least one reactor vessel to which olefin monomer and catalyst components can be added and which contain an agitated bed of forming polymer particles. Typically, catalyst components are added together or separately through one or more valve-controlled ports in the single or first reactor vessel. Olefin monomer, typically, is provided to the reactor through a recycle gas system in which unreacted monomer removed as off-gas and fresh feed monomer are mixed and injected into the reactor vessel. For production of impact copolymers, homopolymer formed from the first monomer in the first reactor is reacted with the second monomer in the second reactor. A quench liquid, which can be liquid monomer, can be added to polymerizing or copolymerizing olefin through the recycle gas system in order to control temperature.

Irrespective of polymerization or copolymerization technique, polymerization or copolymerization is generally carried out under conditions that exclude water and other materials that act as catalyst poisons. Also, polymerization or copolymerization can be carried out in the presence of additives to control polymer or copolymer molecular weights. Hydrogen is typically employed for this purpose in a manner well known to persons of skill in the art. Although not usually required, upon completion of polymerization or copolymerization, or when it is desired to terminate polymerization or copolymerization or at least temporarily deactivate the catalyst or catalyst component of this invention, the catalyst can be contacted with water, alcohols, acetone, or other suitable catalyst deactivators in a manner known to persons of skill in the art.

The products produced are normally solid, predominantly isotactic polyalpha- olefins. Homopolymer or copolymer yields are sufficiently high relative to the amount of catalyst employed so that useful products can be obtained without separation of catalyst residues. Further, levels of stereo-random by-products are sufficiently low so that useful products can be obtained without separation thereof. The polymeric or copolymeric products produced in the presence of the catalyst or catalyst component can be fabricated into useful articles by extrusion, injection moulding, and other common techniques.

The polymer product primarily contains a high crystalline polymer of propylene. Polymers of propylene having substantial polypropylene crystallinity content now are well- known in the art. It has long been recognized that crystalline propylene polymers, described as "isotactic" polypropylene, contain crystalline domains interspersed with some non-crystalline domains. Non-crystalline domains can be due to defects in the regular isotactic polymer chain which prevent perfect polymer crystal formation. The extent of polypropylene stereoregularity in a polymer can be measured by well-known techniques such as isotactic index, crystalline melting temperature, flexural modulus, and, recently by determining the relative percent of meso pentads (%m4) by carbon- 13 nuclear magnetic resonance (^l3C NMR).

The invention described herein is illustrated, but not limited, by the following examples.

Example 1

A supported catalyst component according to the present invention has been prepared and tested for propylene polymerisation as described below.

The Examples each used a magnesium alkoxide support prepared in accordance with the Examples of WO 2005044873 A1.

To a slurry of 0.15g Mg alkoxide support were added 2 ml toluene and 0.1 mmol of the corresponding modifier. The resulting slurry was stirred for 10 min at 100°C. The mixture was then left to settle for 30 min. and the liquid phase was decanted by a pipette.

The remaining solid was then mixed with 1 ml toluene and 1 ml TiCl₄ and then heated to 100°C. The modifier (0.1 mmol)(see Table 1) was then added at 100°C and the reaction mixture stirred at the above temperature for Ih. The slurry was left to settle and cool down to room temperature for 30 min. The liquid was decanted by a pipette.

The solid residue was mixed with 1 ml toluene and 1 ml TiCl₄ and the reaction mixture stirred at 120°C for 30 min. The resulting suspension was left to cool down to room temperature and settle for 30 min. The liquid was decanted and the obtained catalyst was washed with heptane (4 x 2.5 ml, 10 min). The catalyst was then dried under reduced pressure.

Examples 2-9

The procedure of Example 1 was repeated except using the modifiers as shown in Table 1.

Propylene Polymerizations.

Batch slurry phase propylene polymerization reactions were performed in a 2 litre autoclave reactor at 71 °C at a total reactor pressure of 1 .0 MPa, while stirring at 500 revolutions per minute and with a reaction time of 2 hours.

Triethylaluminium (TEA) is used as a co-catalyst together with diisobutyldimethoxysilane as an external donor. The reactor is charged with TEA/donor, catalyst component, hydrogen, and propylene in that order.

In a typical procedure, the dry, nitrogen-purged, 2 litre stainless steel autoclave reactor was charged with catalyst (-20 mg), triethylaluminium (3.6 mL of a 0.75 M solution in heptane), and diisobutyldimethoxy silane (1.0 mL of a 0.15 M solution in heptane), and 850 mL of heptane at 40 C. 7 millimoles of hydrogen was introduced at about 85 kPa. Agitation and heating was started and a 100 kPa pressure drop from a 75 mL vessel containing hydrogen was introduced to the reactor followed by an approximately 30 gram portion of propylene. When the temperature reached 71 °C, the propylene reservoir to the reactor was opened and a constant propylene pressure of 1.0 MPa psig is maintained for one hour. The reactor was then vented and the resulting polymer slurry dumped from the reactor, filtered and dried.

The results are as shown in Table 1 : Table 1

The results show that catalysts according to the present invention produce polypropylene in good yield.

Claims

Claims:

1. A solid, hydrocarbon-insoluble, catalyst component containing magnesium, titanium, and halogen and further comprising a modifier compound with a structure (1): wherein

R¹ is selected from H, aryl or alkyl groups having 1 to 10 carbon atoms,

R² is selected from alkyl groups having 1 to 10 carbon atoms,

R³ to R⁶ are each independently selected from H, alkylaryl, aryl or alkyl groups having 1 to 10 carbon atoms and halogens, but with the proviso that at least one of R⁴ and R⁵ is H, any alkylaryl, aryl or alkyl groups optionally comprising one or more heteroatoms and/or optionally wherein R³ and R⁴ or R⁵ and R⁶ are joined to form a cyclic group.

2. A catalyst component according to claim 1 wherein R¹ is hydrogen or methyl.

3. A catalyst component according to claim 1 or claim 2 wherein R² is an alkyl group selected from methyl, ethyl, propyl and butyl.

4. A catalyst component according to any one of the preceding claims wherein R³ to R⁶ are each hydrogen.

5. A catalyst component according to claim 4 wherein R¹ is hydrogen and R² is an alkyl group selected from methyl, ethyl and butyl.

6. A catalyst component according to any one of claims 1 to 3 wherein at least one of R³ to R⁶ is a halogen

7. A catalyst component according to claim 6 wherein R¹ is hydrogen, R² is methyl, R³, R⁴ and R⁶ are hydrogen, and R⁵ is bromine.

8. A catalyst component according to any one of claims 1 to 3 and 6 wherein at least one of R³ to R⁶ is an alkyl having 1 to 6 carbon atoms.

9. A catalyst component according to claim 8 wherein R¹ is hydrogen, R² is methyl, R³ and R⁵ are t-butyl, and R⁴ and R⁶ are hydrogen.

10. A catalyst component according to claim 8 wherein R¹ is hydrogen, R² is butyl, R³ to R⁵ are hydrogen and R⁶ is methyl.

11. A catalyst component according to claim 1 the modifier having the following structure: wherein

R’ is H, and

R⁷ to R¹⁰ are each independently selected from H, alkylaryl, aryl or alkyl groups having 1 to 6 carbon atoms and halogens, the alkylaryl, aryl and alkyl groups optionally comprising one or more heteroatoms.

12. A catalyst component according to claim 11 wherein R² is ethyl and R¹ and R⁵ to R¹⁰ are all hydrogen.

13. A catalyst component according to any one of the preceding claims wherein the modifier compound with a structure (1) is an internal modifier.

14. A catalyst useful in polymerizing olefins, said catalyst comprising i) a solid, hydrocarbon-insoluble, catalyst component according to any one of claims 1 to 13, and ii) at least one co-catalyst component.

15. A process to polymerize propylene or a mixture of propylene and ethylene or a C₄- C₅ alpha-olefin, which process comprises using a catalyst according to claim 14.