DE10033147A1 - Fragmentable catalyst carrier - Google Patents

Abstract

The invention relates to a fragmentable support for polymerisation catalysts in addition to carrier catalysts and a method for the production thereof. Said carrier catalysts can be used, for example for olefin polymerisation.

Description

The invention relates to fragmentable carriers for Polymerization catalysts and supported catalysts and a Process for their production. The supported catalysts can e.g. B. be used for olefin polymerizations.

Polymerization catalysts, such as transition metal catalysts Polymerization of olefins has been known for a long time. Often used Examples are Ziegler-Natta catalysts and catalysts from Metallocene-aluminoxane. The use of metallocenes for In particular, olefin polymerizations have the advantages that Catalysts are available in a large, structural variety and also can be tailor-made for specific requirements. In addition, the tacticity of the formed polymer can be controlled. The metallocenes are to well-defined catalyst structures, in particular the Single-site systems (single-site catalysts) advantageous products, for example with a narrow molecular weight division and a deliver constant installation of the comonomers. The disadvantage, however, is that Metallocenes usually used for the polymerization of olefins solvents used are soluble. So is one Morphology control of the product not possible or only with difficulty. The Solubility of the catalyst has the particular consequence that Desired polyolefin product is usually obtained as dust with which As a result, the product is difficult to process and that There is a risk of reactor fouling.  

To take advantage of metallocene catalysts with the benefits of a Combining heterogeneous catalysis is therefore customary supported catalysts used. The activity and productivity of such supported catalysts also depend on the type of catalyst used Carrier. As a support material for transition metal catalysts Usually cross-linked polymers or inorganic carrier materials, such as about silica gel used (WO 94/28034, EP-A-295312, WO 98/01481).

The commonly used in a heterogeneous polymerization reaction supported catalysts with a size in the µm range are in the Product installed or the polymer is around the catalyst / carrier Granules formed around. When using inorganic The polymer thus contains carrier materials from inclusions inorganic material that is used in many areas of application of polymers, for example in the formation of films, can be disadvantageous.

There have therefore also been catalyst supports based on the prior art of crosslinked polymers (WO 99/50311; EP-A-0 614 468). This creates irreversibly cross-linked microparticles made of polystyrene and divinylbenzene, as also found in S.B. Roscoe et al., Science 280 (1998), 270-273, are used. Using such However, supported catalysts made from polymer microparticles have relatively little activity. Furthermore, the irreversibly networked and therefore non-fragmentable polymer carriers due to their size Inclusions that are also disadvantageous in many applications.

To increase the activity of the catalysts and the formation of To minimize inclusions, catalyst supports were therefore developed, which consist of fragmentable polymers (WO 99/60035). To do this soluble polymers, which are reversible, for example via a Alder reaction can be cross-linked. When using such materials for supported catalysts in polymerization reactions can  Fragmentation of the carrier down to the soluble individual molecular chains of the polymer occur. While offering significant benefits, such as high productivity can be achieved and also the risk of Inclusions of the carrier material is removed, it was found that a further improvement of the system for some applications would be desirable. In particular, the bulk density is of such Supported catalysts often obtained polymers below the desirable range.

An object of the present invention was therefore a carrier for polymerization catalysts and a supported catalyst as well to provide a process for their manufacture in which the disadvantages of the prior art are at least partially eliminated and by which get supported catalysts with high productivity can be. The product formed should be essentially free of disturbing inclusions and at the same time a high bulk density exhibit.

This object is achieved according to the invention by a method for producing a support for polymerization catalysts, comprising the steps

• a) Manufacture of nanoparticles formed from an irreversible crosslinked polymer and
• b) reversible crosslinking of the nanoparticles, thereby making fragmentable Carrier microparticles are formed.

It has surprisingly been found that the method according to the invention makes it possible to produce carriers which, when used in a polymerization reaction, produce products which are markedly better than known carriers. When using a soluble polymeric carrier as well as with a homogeneous polymerization, a dust-like product with high productivity (<1000 g polymer / g cat) is obtained. If an exclusively reversibly cross-linked carrier is used, particles are obtained, but these are obtained with a low bulk density. The use of non-fragmentable, only irreversibly cross-linked carriers leads to dense particles with a high bulk density, but with a low productivity (about 50 g polymer / g cat). In contrast, high bulk densities and at the same time high productivities can be obtained with the carriers produced according to the invention due to the partially reversibly crosslinked and thus partially fragmentable polymers. The corresponding processes and products obtained are also illustrated in FIG. 1.

The term "irreversibly networked" as used herein means that a Networking carried out in this way among those using the supported Polymerization catalyst prevailing conditions is not solved. An irreversibly crosslinked polymer thus remains among those in the Use of the supported catalysts prevailing Polymerization conditions its integrity and is not fragmented.

The term "reversible crosslinking" as used herein refers to one chemical or / and physical crosslinking of polymer chains or Latex particles, which under the polymerization conditions in which the supported catalysts are used, dissolved or reversed is made. The networking ties were thus at Use of the supported catalyst cleaved and the support fragmented.

Usual polymerization conditions, in particular Olefin polymerization conditions under which the supported catalysts are used, have reaction temperatures of -50 ° C to 300 ° C, in particular from 0 ° C to 150 ° C. Such polymerizations will usually in organic solvents such as isobutane or  Hexane, in suspensions, in liquid monomers or in the gas phase, e.g. B. carried out in a stirred gas phase or in a gas phase fluidized bed. Irreversible crosslinks remain intact under the reaction conditions, while reversible crosslinks are solved.

The term "polymer" as used herein includes both Homopolymers in which a single monomer has been reacted, as well as copolymers in which two or more different Monomers have been reacted to form the product. According to the invention, the carrier is preferably made of an organic Polymer formed.

The formed from an irreversibly cross-linked polymer and thus in Course of a later performed using the carrier Polymerization reaction resistant (non-decomposable) nanoparticles preferably have an average particle size of 10 nm to 400 nm, in particular from 30 nm to 150 nm. The size of the nanoparticles will especially set to be below the wavelength of visible light to avoid scattering centers in the later product cause. The size of the nanoparticles from irreversibly cross-linked Polymer can be selected by a suitable choice of production conditions z. B. Spray drying can be set. But it is also possible to have larger ones Particles by suitable grinding processes, such as grinding or Spray drying to bring to the desired size.

These nanoparticles then become partial through reversible crosslinking fragmentable carrier microparticles produced, which preferably a Size from 1 µm to 800 µm, more preferably from 10 µm to 400 µm and most preferably have from 30 µm to 300 µm. This Carrier microparticles indicate that for the implementation of a heterogeneous Required size.  

The two-step method according to the invention causes a material is obtained by targeting two different types of links available. The irreversibly networked and therefore not fragmentable Nanoparticle spheres are reversibly cross-linked to one another larger and suitable as a carrier for heterogeneous catalysis To form carrier microparticles. Under the conditions of use of the wearer then the reversible networks or bonds are broken, so that the carrier microparticle disintegrates into the nanoparticles. Another However, fragmentation, for example down to the individual molecular chains, occurs Not because of the irreversible cross-linking of the nanoparticles. In this way a fragmentable carrier material is obtained, which is defined as a predetermined extent and up to a predetermined particle size fragmented.

Step (a) of the method according to the invention comprises the production of irreversibly cross-linked polymeric nanoparticles. The irreversible networking can z. B. by copolymerization of monomers and crosslinking agents and / or subsequent irreversible crosslinking of polymer chains. In principle, the nanoparticles can be formed from any polymers, for example from polymers that are formed by polyaddition, polycondensation or radical polymerization. The nanoparticles are preferably produced by reacting at least one monomer which has at least one olefinically unsaturated bond with at least one crosslinking agent which has at least two olefinically unsaturated bonds. Suitable olefinically unsaturated monomers preferably have the formula I.

in which R ¹ , R ² , R ³ and R ⁴ independently of one another are hydrogen, halogen, in particular F, a branched or unbranched alkyl, alkenyl, aralkyl or aryl radical which may optionally contain and / or be substituted by heteroatoms.

All alkyl, alkenyl, aralkyl and aryl groups mentioned herein preferably have from 1-30 carbon atoms, in particular from 1-16 carbon atoms. Suitable heteroatoms which may be contained in the radicals are, for example, O, S, N, P etc. Suitable substituents which the groups may have are in particular -OH, -NH ₂ , -CN, -COOH, and acid derivatives, such as such as acid amides, esters, etc.

At least one of the radicals R ¹ , R ² , R ³ and R ⁴ is preferably a substituted or unsubstituted phenyl, pyrenyl, naphthyl or alkenyl. Preferred monomers I are styrene, butadiene and isoprene. The properties of the polymer formed, for. B. the polarity of the polymeric carrier can be modified in a desired manner, for example by introducing polar groups, such as acrylic acid or methacrylic acid esters or nitriles. Furthermore, it is possible to select the support so that it is as similar as possible to the polymer end products produced in heterogeneous catalysis using the support. For example, a support in which styrene has been used as monomer I can preferably be used for a styrene polymerization.

Any agent which can be used to crosslink two polymer chains or which introduces a branching point into a polymer can be used as the crosslinking agent. Crosslinking agents are preferably used which have at least two olefinically unsaturated bonds which are not conjugated. The crosslinking agent preferably has the formula II

wherein R ⁶ , R ⁷ , R ⁸ and R ⁹ each independently represent hydrogen, halogen, in particular F, an alkyl, alkenyl, aralkyl or aryl radical which is branched or unbranched and which may contain and / or be substituted by heteroatoms can and
R ^{5 represents} a direct chemical bond or an alkyl, alkenyl, aralkyl or aryl radical which can be linear or branched and can optionally contain or / and be substituted by heteroatoms.

Preferred crosslinking agents are divinylbenzene, divinylnaphthalene and Diisopropenylbenzene.

About the reversible link provided later and about binding sites prepare for the catalyst is used in the reaction to produce the insoluble nanoparticles preferably reacted with another monomer, which in addition to a polymerizable group, in particular one olefinically unsaturated group at least one further functional Group carries. This functional group can be the later desired functional group, such as a hydroxy group, a Amine group etc. act or it is a substitutable Leaving group, for example a halogen, especially chlorine, bromine, Iodine.

The further functionalizing monomer preferably has the formula III

on what
R ¹ and R ^{2 are} as defined above,
A is a direct chemical bond or a linking group and
B is a functional group, in particular a functional leaving group.

In formula III, A is in particular a group

where n is an integer from 0 to 8. However, A can also be a saturated, unsaturated or aromatic linking group which may optionally contain heteroatoms and may be substituted. B is preferably selected from halogen, in particular bromine, chlorine, iodine and C ₁ -C ₈ alkoxy. Particularly preferred compounds of the formula III are bromostyrene, chloromethylstyrene, methoxymethylstyrene and methoxystyrene.

Nucleophilically substitutable leaving groups, for example tosylate, trifluoroacetate, acetate or azide, can also be used as substitutable leaving group B. The substitutable leaving group X can also be an organometallic functional group such as Li or Mg X ⁴ , where X ^{4 represents} halogen, in particular fluorine, chlorine, bromine or iodine.

To prepare the polymer in step (a), several different comonomers and several different crosslinking agents be used. However, it is preferred to have only one monomer implement a networker. The proportion of the monomer, for example with Formula I is preferably 20-80% by weight, more preferably 30-60 % By weight, the proportion of crosslinker II preferably 2-30% by weight, more preferably 5-20% by weight and the proportion of the functional Monomer III is preferably from 0-60% by weight, more preferably of 30-60% by weight based on the total weight of the Polymer. When using a monomer which itself as Crosslinkers can act on the addition of an additional Crosslinking agents are dispensed with.

In a particularly preferred embodiment, a copolymer is from 40-50% by weight styrene, 5-15% by weight divinylbenzene and 40-50 % By weight p-bromostyrene produced.

In a further preferred embodiment, at least one of the monomers used has the formula Ia in step (a)

in which R ¹ and R ^{2 have} the meaning given above, R ^{10 is} a linking group, in particular a direct chemical bond or an alkyl, alkenyl, aralkyl or aryl group, which can be linear or branched and optionally contain heteroatoms or / and can be substituted and
C is a polyether residue.

The radical C preferably comprises a linking group which connects the polyether radical to the rest of the molecule. C preferably has the formula OR ¹³ -O- [R ¹¹ -O-] _m -R ¹² , where R ^{12 is} hydrogen, an alkyl, alkenyl, aralkyl or aryl radical, which can be linear or branched and optionally contain heteroatoms or / and can be substituted.

R ¹³ is preferably a linking group, for example an alkyl, alkenyl, aralkyl or aryl group. Each occurrence of R ¹¹ is independently an alkyl, alkenyl, aralkyl or aryl group, which can be straight-chain or branched and optionally contains or is substituted by further heteroatoms. m is preferably 1-20, particularly preferably 2-10.

Particularly preferred examples of the radical C are polyethylene glycol (PEG), Polypropylene glycol (PPG), polytetramethylene glycol etc. as well as block and Mixed copolymers containing PEG or / and PPG. Such one Monomers containing polyether substituents are preferred together with a monomer I and chloromethylstyrene as functionalized Monomers implemented.

In a further preferred embodiment, the production of insoluble nanoparticles in the presence of a block copolymer. This block copolymer can be embedded in the formed nanoparticles or be covalently bound to and in the nanoparticles. preferred Block copolymers are so-called polymeric surfactants, such as such as polystyrene-polyethylene glycol block copolymers (so-called Goldschmidtpolymers) or other hydrophilic-hydrophobic block copolymers.

The preparation of the insoluble nanoparticles in step (a) of the invention is preferably carried out by emulsion polymerization. To do this in particular one or more monomers, one or more crosslinkers and optionally one or more functionalizing monomers in Implemented presence of an emulsifier. Suitable emulsifiers are  for example SDS (sodium dodecyl sulfate) or Sodium dioctylsulfosuccinate. After the emulsion polymerization, the Emulsifier removed again, for example by centrifugation or Filtration. By choosing the reaction conditions at Emulsion polymerization makes it possible to have particles of a predetermined size To produce nanometer range.

When using the preferred monomers of the formula mentioned above Ia or when carrying out the emulsion polymerization in the presence of a Block copolymer can be added to a separate low molecular weight Emulsifier can be dispensed with. The monomers of the formula Ia act on their own as nonionic emulsifiers, the hydrophilic part of a polyether with a large number of oxygen atoms, preferably from 2-20, consists in particular of 3-10 oxygen atoms. Even when used of block copolymers, in particular of polymeric surface-active Means can be added to the addition of low molecular weight emulsifiers Emulsion polymerization can be dispensed with.

According to the invention, the irreversibly crosslinked nanoparticles obtained in step (a) are reversibly crosslinked in a second step (b), as a result of which fragmentable carrier microparticles are formed. The reversible crosslinking can be brought about by any linkages which are stable enough to hold the particles together during the application of the catalyst and at the same time labile enough to cause the bonds to be broken and thus the carrier to fragment under polymerization conditions. The reversible crosslinking of the nanoparticles is preferably brought about by a Diels-Alder reaction, fragmentation being carried out here by a Retro-Diels-Alder reaction. A suitable reversible crosslinking can also be achieved through interactions of nucleophilic groups, e.g. B. ether groups, on the polymer with cocatalysts, for example aluminoxanes and in particular methylaluminoxanes. In order to be able to reversibly crosslink the nanoparticles, appropriately substituted monomers can be reacted, but it is also possible to first functionalize the nanoparticles before the reversible crosslinking, this procedure being preferred. For example, the diene functions can be applied to the surfaces of the nanoparticles by suitable reactions if reversible crosslinking by means of a Diels-Alder reaction is desired. Such functionalization with diene functions is preferably achieved by reacting the nanoparticles with a cyclopentadienyl compound or / and a fulvene compound. The reaction can be carried out on unsubstituted nanoparticles, for example nanoparticles formed from polystyrene and divinylbenzene, but is preferably carried out on nanoparticles substituted with a leaving group. Such nanoparticles are produced by copolymerization of at least one of the abovementioned monomers III which contain a substitutable leaving group. Suitable cyclopentadienyl compounds IV or fulvene compounds IVa have, for example, the formulas

wherein,
R ¹⁴ , R ¹⁵ , R ¹⁶ and R ¹⁷ each independently represent hydrogen, halogen, C ₁ -C ₁₀ alkyl, substituted or unsubstituted phenyl and / or one of these radicals represents a group -QR ¹⁹ R ²⁰ X ² , in which Q denotes carbon, CR ¹⁹ R ²⁰ C, germanium or silicon,
R ¹⁹ , R ²⁰ independently of one another are hydrogen, methyl, ethyl or phenyl and
X ^{2 represents} halogen, methyl, methoxy or ethoxy and
R ^{18 is} independently C ₁ -C ₄ alkyl or substituted or unsubstituted phenyl each time it occurs.

In addition to unsubstituted cyclopentadiene, 1 to 4-fold substituted cyclopentadienes can also be used as the cyclopentadienyl compound IV. Suitable substituents are in particular C ₁ -C ₁₀ alkyl groups, such as methyl, ethyl and the various isomers of propyl, butyl, pentyl, hexyl, heptyl, octyl, nonyl and decyl. Furthermore, the radicals can also represent substituted or unsubstituted phenyl radicals. It is further preferred that one of the radicals is a group -QR ¹⁹ R ²⁰ X ² , in which the variable Q preferably represents silicon, the variables R ¹⁹ and R ²⁰ preferably methyl and the group X ² preferably halogens, methyl, methoxy or Means ethoxy. A group -QR ¹⁹ R ²⁰ X ^{2 of} the formula -Si (CH ₃ ) ₂ X ² is particularly preferred. Such a group can be used to build a bridged metallocene structure on a copolymer backbone. Most preferred, however, is unsubstituted cyclopentadiene.

Suitable fulvene compounds IVa may be unsubstituted or substituted on the five-membered ring, the substituents being the same as those above for the cyclopentadienyl compounds III. Particularly preferred fulvene compounds IVa are unsubstituted on the 5-ring. Preferred fulvene IVa are substituted twice on the methylene carbon by radicals R ¹⁸ , preference being given to methyl, ethyl or the different isomers of propyl or phenyl. A particularly preferred Fulven IVa is Dimethylfulven.

Suitable processes for the reaction of polymers with cyclopentadienyl or fulvene compounds are known to the person skilled in the art. For example functionalization by reaction with a strong base, such as Butyllithium or elemental alkali metal, such as sodium, and Mix with the appropriate cyclopentadienyl or fulvene compound be preserved.  

In a further preferred embodiment, the surface of the Nanoparticles additionally functionalized with hydroxyl groups. Such Functionalization can be done, for example, by implementing functional ones Bromine groups in the nanoparticles can be effected with n-BuLi and acetone. It is particularly preferred to have a simultaneous Hydroxy group functionalization and diene functionalization by Implementation of the nanoparticles with n-BuLi, acetone and dimethylfulven perform.

A reversible crosslinking through a Diels-Alder reaction can then for example by heating a suspension of the nanoparticles in one suitable solvent, for example toluene to about 50-100 ° C. be preserved. In this case, the microparticles are shaped during drying, preferably spherical shapes preferred are. Particles obtained during reversible crosslinking can if necessary, by known comminution methods to the desired Size.

The nanoparticles before the reversible crosslinking or the microparticles after the reversible crosslinking are preferably further functionalized to a non-covalent binding of the catalysts suitable for the polymerization enable. The catalysts are preferably bound via nucleophilic or charged groups on the support, such as ether, Aluminoxanes, aluminum alkyl or boron compounds. For further The carrier particles are therefore preferably functionalized with a (a) aluminoxane, (b) aluminum alkyl, (c) polyether or / and (d) one Boron compound implemented. Linking these functional groups the polymeric carrier is preferably carried out via hydroxy compounds, which like can be introduced as described above. When implemented with Aluminoxanes, for example methylaluminoxane (MAO), are formed in the polymeric supports according to the invention from a silica-analogous system,  namely an association of MAO with the oxygen of one Hydroxy function (O → MAO).

A polyether provided with a leaving group, such as a tosilated polyether, is preferably used as the polyether. When reacting with the polymeric carrier, the ether OH groups are transetherified. Suitable tosylated polyethers have in particular the formula

Tos- [OR ²¹ -] _o -OR ²¹

wherein Tos is a leaving group, in particular tosyl and R ²¹ each independently represents an alkyl, alkenyl, aralkyl or aryl radical, which may be branched or linear and may optionally contain and / or be substituted by further heteroatoms. o is preferably from 2-10.

Furthermore, it is also possible to use a boron compound for the carrier material to functionalize. Suitable boron compounds used as cocatalysts for Polyolefin polymerizations are widely used by those skilled in the art known. Tris (pentafluourphenyl) boron is particularly preferably used. This is covalently attached to the carrier and by adding a strong base, for example N, N-dimethylaniline activated.

The catalyst, for example a metal complex, is bound preferred over non-covalent interactions. The bond can be through the coordination of nucleophilic groups on the carrier with a complex MAO and the metal compound, or by the electrostatic Interaction between the negatively charged boron compound on the support as well as a positively charged metal complex. The non-covalent Binding of the catalyst to the support enables a universal Use for a wide range of polymerization catalysts. The Activation by means of a boron compound also has the advantage that  can be completely dispensed with inorganic additives and a catalytic activity only on the supported catalyst is observed since removal of the boron compound from the support with a loss of charge and thus inactivation of the catalyst accompanied.

The invention thus further relates to a method for producing a supported polymerization catalyst, which is characterized is that a carrier made as described above has a Polymerization catalyst or a precursor thereof is added.

The catalyst can be added to the support, in particular, simply by adding by impregnation.

Suitable polymerization catalysts are, for example Transition metal catalysts, such as Ziegler-Natta catalysts or Metallocene catalysts. Basically, everyone can get one Polymerization reaction suitable catalysts according to the invention be immobilized. Suitable catalysts are, for example described by G. Hlatky, Chem. Rev. 100 (2000), 1347-1376.

Preferred catalysts are monocyclopentadienyl compounds of the formula VI

CpM (X ³ ) ₃ VI,

in which Cp is a substituted or unsubstituted cyclopentadienyl radical,
M represents Ti, Zr or Hf and
X ³ for each occurrence is independently halogen, hydrogen, C ₁ - C ₁₀ alkyl or C ₁ -C ₁₀ -alkoxy or amido.

The cyclopentadienyl radical is preferably methyl, ethyl, propyl or butyl substituted. The cyclopentadienyl ring can also be part of a complicated ring system. Mono- or are most preferred  Dialkylcyclopentadienyl, substituted or unsubstituted fluorenyl, Indenyl or tetrahydroindenyl residues. Catalysts can also be used be used with cyclopentadienyl residues, which with a Chlorodimethylsilyl group are modified. Such metallocene complexes can be used to make bridged supported metallocenes.

Other suitable catalyst compounds have the formula VIa M (X ³ ) ₄ , where M in turn means titanium, zirconium or hafnium. Preferred radicals X ³ are halogen, in particular chlorine and methyl.

Precursors of polymerization catalysts are in particular Compounds that are in contact with the carrier or / and Cocatalyst form the active catalyst species or by simple Derivatization steps are converted into an active catalyst species can.

The support can first be used with a cocatalyst or activator, such as such as an aluminum compound, functionalized and then with be added to a catalyst. But it is also possible that Catalyst together with an aluminum compound such as one Aluminoxane or a trialkylaluminum compound, in one step to apply the carrier.

The invention further relates to a fragmentable carrier for Polymerization catalysts by the method described above can be produced. Such a carrier consists in particular of irreversible cross-linked nanoparticles that reversibly cross-link to carrier micro-particles are.

Another object of the invention is that by implementing the fragmentable carrier available with a polymerization catalyst supported catalyst. With such a catalyst can at  Polymerization, especially in the case of olefin polymerization with products high bulk density of <200 g / l, in particular <350 g / l and especially preferably <400 g / l with simultaneous high productivity of <300 g / g, preferably <500 g / g can be obtained. Furthermore, the worn Catalysts a high activity of <400 kg PE / (mol Zr h bar), in particular <500 kg PE / (mol Zr h bar).

The supported catalysts of the invention make it possible due to the microparticles undergo heterogeneous catalysis, the carrier particles in the Fragment the course of the polymerization reaction to the nanoparticles. This ensures high activity and productivity of the catalyst achieved while producing a product with high bulk density can be. A further decay of the carrier material up to individual polymer strands occurs due to the irreversible crosslinking of the polymeric nanoparticles on the other hand.

Finally, the invention also relates to a copolymer which Process steps (a) and (b) is available. Such a copolymer can also for other areas of application except as a carrier for Polymerization catalysts are used, in which a partial Fragmentation is desired.

The supported catalyst according to the invention can be used in particular for the polymerization of olefins. Suitable olefins which can be reacted with are, for example, alpha-olefins, functionalized olefinically unsaturated compounds, such as ester or amide derivatives of acrylic or methacrylic acid, such as acrylate, methacrylate or acrylonitrile. Non-polar olefinic compounds are preferably reacted, such as linear or branched C ₂ -C ₁₂ alk-1-enes, in particular linear C ₂ -C ₁₀ alk-1-enes, such as ethylene, propylene, but-1-ene, Pent-1-ene, hex-1-ene, hept-1-ene, oct-1-ene, non-1-ene, dec-1-ene or 4-methyl-pent-1-ene or unsubstituted or substituted vinyl aromatic Links. Examples of preferred vinyl aromatic monomers are styrene, p-methylstyrene, p-chlorostyrene, 2,4-dimethylstyrene, 4-phenyl-biphenyl, phenylnaphthalene or phenylanthracene.

It is also preferred to use copolymers of mixtures various olefins, especially alpha-olefins.

The polymerization of olefins can be in solution, in suspension, in liquid Monomers or be carried out in the gas phase. In doing so Usual polymerization conditions used, i.e. temperatures in the Range from -50 to 300 ° C, preferably in the range from 0 to 150 ° C and Pressures in the range of 0.5-3000 bar, preferably in the range of 1-80 bar.

The produced with the catalysts supported according to the invention Polyolefins differ from the previously known olefins in that that they have a high bulk density and at the same time only carrier inclusions have a size in the nanometer range. This will be beneficial Properties, in particular for film production from the polyolefins receive.

The invention is further elucidated by the attached figures and the examples explained.

Fig. 1 shows the growth process of polymer particles using different catalyst particles.

In Fig. 1 (a), a non-fragmentable supported catalyst is used. This results in large, high density particles, but the polymerization process is low in productivity.

Figure 1 (b) shows polymer growth on a catalyst supported on a soluble support. The catalyst is evenly distributed in the reaction medium and the numerous centers lead to a dust-like product. The advantage here is the high productivity in relation to the catalyst. Similar behavior is observed in homogeneous catalysis.

In Fig. 1 (c) the use of a catalyst is shown in a purely reversible crosslinked carrier. In the course of the reaction, the carrier dissolves completely, so that numerous, very small active centers are formed and a product with a low bulk density, in which many air spaces are enclosed, is obtained.

Figure 1 (d) shows polymer growth using a supported catalyst of the invention using reversibly cross-linked insoluble nanoparticles. In the course of the reaction, the microcarrier particle disintegrates into nanoparticles, which in turn are stable and do not disintegrate further. This results in a product with a high bulk density and small air spaces and at the same time high productivity.

Fig. 2 shows the functionalization and reversible cross-linking of the carrier according to the invention. The first step shows a functionalization with a diene group (for a later Diels-Alder reaction) using dimethylfulvene and the introduction of a hydroxy group using acetone. In the second process step, reversible crosslinking of the nanoparticles is then achieved by heating via a Diels-Alder reaction.

Fig. 3 shows different ways of the nanoparticles or reversible crosslinked microparticles to functionalize, to provide non-covalent binding sites for a polymerization catalyst. The functionalization can be carried out by reaction with MAO to form O → MAO adducts, by reaction with a tosylated polyether to form polyether-derivatized particles and by reaction with a strong base, for example dimethylaniline and a boron compound, for example tris (pentafluorophenyl) boron.

Fig. 4 the non-covalent bond illustrates a catalyst such as a metallocene in the inventive carrier. The binding takes place via interactions between polyether chains on the support, MAO and the metallocene.

Fig. 5 illustrates a further possibility to attach a catalyst non-covalently to the support. In a first step, a boron activator is covalently bound to the carrier. The catalyst is bound by electrostatic interactions. Another activator, such as MAO, is not required for this procedure.

Fig. 6 illustrates a preferred embodiment for the formation of irreversible cross-linked nanoparticles by reaction of styrene, bromostyrene and divinyl benzene in an emulsion polymerization in the presence of SDS. The bromine-functionalized nanoparticles are then reacted with n-BuLi, dimethylfulvene and acetone, whereby hydroxy and diene functionalities are obtained on the surface.

FIG. 7 shows how such nanoparticles can be cross-linked reversibly via a Diels-Alder reaction, as a result of which OH-functionalized microparticles are formed. These microparticles can then be functionalized with MAO, PEO or BPH ^F ₃ as described above in order to serve as a support for catalysts.

example 1

Preparation of a Tos-PEG monomethyl ether

30 ml of 5 M NaOH (5.7 g of NaOH in 30 ml of H) are added to a solution of 0.1 mol (31.9 ml, 35 g) of PEG monomethyl ether (M _n = 350, Aldrich Co.) in 250 ml of THF ₂ O) added. The mixture is stirred and cooled to 0 ° C in an ice bath. A solution of 0.09 mol (17.2 g) TosCl in 25 ml THF is added dropwise. Stirring is continued for 3 hours and the phases are separated in a separatory funnel. The organic phase is dried over MgSO ₄ . After one night it is filtered and evaporated at room temperature and under slightly reduced pressure on a rotary evaporator to give a pale yellow oil. No further cleaning is required.

Example 2

Production of a non-irreversibly cross-linked copolymer polystyrene-co-4-Br-styrene (comparative example)

A copolymer of styrene and 4-bromostyrene used in a ratio of 1: 1 (molar ratio). On Mixture of 39 mmol styrene (4.1 g, 4.5 ml), 39 mmol 4- Bromostyrene (7.2 g, 5.2 ml), AlBN (0.05 g, 0.3 mmol) and Toluene (10 ml) is degassed and at 70 ° C for 24 hours heated. After cooling to room temperature, 20 ml Dichloromethane added and the mixture in 1 l of methanol precipitated. The polymer is filtered, again in 50 ml Dissolved dichloromethane and precipitated in 500 ml of methanol. After drying in a vacuum oven at 60 ° C overnight, the polymer can be reused.

Example 3

Synthesis of a carrier using a soluble polymer (comparative example)

The polystyrene-co-4-Br-styrene copolymer (2 g, 6.88 mmol Br- Units) is dissolved in 200 ml of dry THF and the Solution is cooled to -78 ° C. Then 1.2 eq tert- BuLi (8.5 mmol, 5 ml) added. After stirring for 10 minutes 0.3 eq (2.06 mmol, 0.15 ml) acetone and 0.7 eq (4.8 mmol, 0.58 ml) of dimethylfulven added. After stirring for another 10 minutes, 0.3 eq (2.06 mmol, 0.91 ml) of Tos- PEG added. After 1 hour, the mixture is left on Warm room temperature and then it is in 2 l of hexane precipitated. The polymer is filtered, in 100 ml choroform dissolved and again precipitated in 1 l of hexane. Under It becomes high vacuum for 48 hours at room temperature dried.

Example 4 Production of an irreversibly cross-linked copolymer

Styrene, 4-Br-styrene and divinylbenzene (DVB) in the amounts given in Table 1 were mixed. The monomers were added to a solution of surfactant (SDS), water and KOH (1 M). After 30 minutes the mixture was heated to 60 ° C and the polymerization was started by adding K ₂ S ₂ O ₈ and then carried out under an argon atmosphere with mechanical stirring (600 rpm) for 24 hours. The particles were separated by centrifugation (3 × 50 min at 1800 rpm in an Ultrafrel®-15 centrifugal filter device, Biomax-50K NMWL membrane) and freeze-dried.

Table 1

Polymerization with SDS

This caused irreversibly cross-linked latex particles (Nanoparticles) obtained.

Example 5

Preparation of a carrier using latex particles

Particles formed from 48 mmol styrene units 48.6 mmol of 4-Br styrene units and 9.6 mmol Divinylbenzene units (9% cross-linked), as Starting polymer used. These nanoparticles were like  described in Example 3 with diene groups and Functionalized polyether groups.

Example 6

Preparation of a supported catalyst

For reversible cross-linking, 3 ml of tulol are first added to 0.5 g of the carrier material and this suspension is heated to 85 ° C. for 72 hours. After the solution has cooled to room temperature, 1 ml of MAO is added in order to remove water which may be retained in the PEG chains of the carrier. The mixture is stirred overnight and 3 ml of a solution of 0.2 mmol (0.1104 g) Me ₂ Si (2-MeBenzlnd) ₂ Zr ₂ Cl ₂ in 20 ml MAO are added to a ratio of 35 µmol zirconium ozen to give per 1 g of carrier. After stirring for 10 minutes, the mixture is poured into 100 ml of hexane. After removing the supernatant, washing the residue with a further 100 ml of hexane and drying under high vacuum overnight, the heterogeneous supported catalyst was obtained.

Example 7 Ethylene polymerization using the partial fragmentable supported catalyst

Ethene was in isobutane for 60 minutes at 40 bar and 70 ° C using the catalyst prepared in Example 6 polymerized. Here, a polyethene with a Obtain bulk density of 400 g / l. The activity of the The catalyst was 520 kg PE / (mol Zr h bar) and the Productivity 680 g PE / g catalyst. The Al / Zr ratio was 300 with an amount of 33 µmol Zr / g catalyst.

In contrast, one was alike polymerization carried out using a none irreversibly cross-linked carrier containing nanoparticles (according to Example 3) a product with a low bulk density of <200 g / l obtained.

Example 8 Production of functionalized latex particles

2 g of the latex particles produced according to Example 4 with a molar composition of 45% styrene (662 mg, 6.3 mmol), 45% bromostyrene (1155 mg, 6.3 mmol) and 10% Divinylbenzene (183 mg, 1.4 mmol) are dissolved in 50 ml THF suspended, cooled to -78 ° C and with 4.3 ml n- Butyllithium solution (1.6 M) in hexane (6.9 mmol, 1.1 eq) added. After 15 minutes of reaction time will be simultaneous  292 mg acetone (5.0 mmol, 0.8 eq) and 267 mg Dimethylfulvene (2.5 mmol, 0.4 eq) was added. To The cooling is removed for a further 30 minutes and the Mix the mixture until it warms to room temperature Has.

The mixture is worked up in 250 ml of methanol given and the solvent on a rotary evaporator almost completely removed. Here the Nanoparticles together and become filterable. Cleaned become them by repeated slurrying with methanol and then filtering. After drying in The functionalized carrier particles are obtained under high vacuum. For crosslinking, 500 mg of the particles in 3 ml of toluene slurried and stirring for 36 hours at 80 ° C heated.

For support over methylaluminoxane, 2 ml of a solution of methylaluminoxane toluene (10% by weight) are added to the suspension of the nanoparticles and stirred for 18 hours. Then 2 ml of a 0.015 M solution of a metallocene in methylaluminoxane solution are added. The mixture is stirred overnight and the solvent is removed. A catalyst of the following composition is obtained:
500 mg polymer + 481 mg MAO = 981 mg carrier 30 µmol metallocene.
From this follows: 29 µmol Zr / g cat., Al-Zr = 300

Example 9 Carried with borane

Cross-linked nanoparticles are formed into a suspension under Stir 23 mg N, N-dimethylaniline (0.19 mmol, 0.12 eq) and after 30 minutes 88 mg tris (pentafluorophenyl) borane (0.17 mmol, 0.11 eq) added. After stirring for a further 30 minutes if the polymer is allowed to settle, the supernatant is removed Solution, washes with 10 ml of hexane and dries the carrier in Vacuum.

The polymer is carried in 2 ml of a 1 M solution of Trisisobutyl aluminum slurried in hexane for 1 hour stirred and with 1 ml of a 0.015 M solution of a metallocene added in trisisobutyl aluminum. An almost instantaneous Color change indicates the formation of the active species.

The catalyst is not dried, but as a suspension used and has the composition 500 mg of polymer, 170 µmol boron, 50 µmol metallocene, i.e. 30 µmol Zr / g cat.

Example 10

Formation of nanoparticles using a surfmer

4-vinyl phenol (1) was prepared according to the procedure of Corson et al., J. Org. Chem. 23 (1958), 544-548.

K ₂ CO ₃ (3.45 g, 2.5 × 10 ^-2 mol) was added to a solution of (1) (1.5 g, 1.25 × 10 ^-2 mol) dissolved in DMF (40 ml) , The solution was stirred at 80 ° C for 15 minutes and then 11-bromundecanol (3.15 g, 1.25 x 10 ^-2 mol) in DMF (10 ml) was added. The resulting mixture was stirred at 80 ° C for 15 hours and then filtered. Water (50 ml) was added to the mixture and then the mixture was extracted with CH ₂ Cl ₂ . The organic phase was washed with water and dried (MgSO ₄ ). The residue was purified by column chromatography on silica gel with EtOAc / petroleum ether (20/80) to give a white solid (2 g, 55%) which was 4-vinyl-phenyloxyundecanol (2).

Compound 2 (2 g, 6.89 x 10 ^-3 mol) was dissolved in pyridine (15 ml) and then cooled to 0 ° C. With vigorous stirring, p-TsCl (1.5 g, 7.8 × 10 ^-3 mol) was added and the mixture was then stirred at room temperature for 5 hours, poured onto ice and extracted with EtOAc (100 ml). The organic phase was washed with water (50 ml), brine (50 ml) and dried (MgSO ₄ ). The residue was purified by column chromatography on silica gel with EtOAc petroleum ether (20/80) to give a yellow oil (2.3 g, 75%), which was 4-vinyl-phenyloxyundecanyl-p-toluenesulfonate ( 3) acted.

NaH (0.08 g, 2 × 10 ^-3 mol, hexane washed) was suspended in dry THF (10 ml) and poly (ethylene glycol) methyl ether 350 (0.57 g, 1.63 × 10 ^-3 mol) was added dropwise added. The mixture was stirred at room temperature for 30 minutes. Compound 3 (0.53 g, 1.19 x 10 ^-3 mol) in THF (5 ml) was added and the resulting mixture was stirred at 60 ° C for 24 hours. The solvent was evaporated and the residue dissolved in EtOAc (20 ml), washed with water (20 ml), brine (10 ml) and dried (MgSO ₄ ). The product is obtained as a yellow oil (0.59 g, 95%), which is a Surfmer (4).

Example 1 l emulsion

An emulsion polymerization was carried out as described in Example 4 using 6.82 mmol of styrene, 0.61 mmol of DVB, 0.97 mmol of Surfmer (4), 0.03 mmol of K ₂ S ₂ O ₈ and 30 ml of water. An addition of an emulsifier, such as SDS, was not necessary in this case due to the use of the surfmer (4). An irreversibly cross-linked product with a Zav of 164 nm was obtained.

Example 12 Manufacture of foils

Made from propylene polymers using Catalysts supported according to the invention transparent films were produced. In a press 100 mg was prepared according to the invention at 160 ° C. Polypropylene heated for 10 minutes and then with a Pressure of 20 k Pa within 1 minute the films are produced. The films were then cooled in cold water. As is common for isotactic polypropylene, these are Films not clear, but homogeneously milky cloudy. But there are no inhomogeneities, so-called scholarships. The homogeneous distribution was also over the convocal Proved fluorescence microscopy, using colored ones for this purpose Carriers were used. The fluorescence shows where the carrier is in the film. When using the The carrier produced according to the invention is the dye distributed homogeneously in the film.

These results show that the carrier according to the invention in Fragmented fragments that are smaller than the wavelength of the visible light.

In comparison, polypropylene films were formed that was made using metallocenes which is completely irreversibly cross-linked with divinylbenzene Carriers were made available, such as in WO 99/50311, EP-0 614 468 and S. B. Roscoe et al., Science 280 (1998), 270-273. at such inhomogeneities were clearly recognizable in such foils was a large number of grants and spreading centers that were easily visible.  

This shows that transparent films show inhomogeneities if they are made from a polymer in which the Could not fragment the catalyst.

Claims (31)

1. A method for producing a support for polymerization catalysts comprising the steps

• a) Manufacture of nanoparticles, formed from an irreversibly crosslinked polymer and
• b) reversible crosslinking of the nanoparticles, whereby fragmentable carrier microparticles are formed.

2. The method according to claim 1, characterized, that those formed from an irreversibly cross-linked polymer Nanoparticles have an average particle size of 10 nm to 400 nm exhibit. 3. The method according to claim 1 or 2, characterized, that the fragmentable carrier microparticles are medium Have particle size from 1 micron to 800 microns. 4. The method according to any one of the preceding claims, characterized, that the nanoparticles are made by implementation at least one monomer which is at least one olefinic has unsaturated bond, with at least one Crosslinking agent which has at least two olefinically unsaturated Has bonds. 5. The method according to claim 4, characterized in that an olefinically unsaturated monomer of the formula I.
reacted with a crosslinking agent of the formula II
wherein R ¹ , R ² , R ³ , R ⁴ , R ⁵ , R ⁷ , R ⁸ and R ⁹ each independently represent hydrogen, halogen, in particular F, an alkyl, alkenyl, aralkyl or aryl radical which is linear or is branched, and may optionally contain or / and be substituted, where R ^{5 is} not hydrogen. 6. The method according to claim 5, characterized, that as an olefinically unsaturated monomer styrene and / or as Crosslinking agent divinylbenzene is used. 7. The method according to any one of claims 4-6, characterized, that another in the reaction to produce the nanoparticles Monomer is implemented, which is at least one olefinic  unsaturated group and at least one further functional group wearing. 8. The method according to claim 7, characterized in that the further monomer has the formula III
wherein R ¹ and R ^{2 have} the meaning given in claim 5,
A represents a direct chemical bond, an alkyl, alkenyl, aralkyl or aryl radical, which may be linear or branched and may optionally contain or / and be substituted by heteroatoms, and
B represents a functional group or a leaving group. 9. The method according to claim 8, characterized, that the further monomer is selected from the group consisting of bromostyrene, chloromethylstyrene, methoxymethylstyrene and methoxystyrene. 10. The method according to any one of claims 4-9, characterized,  that the monomer I, the crosslinking agent II and the functional Monomer III used in parts by weight of 30-60: 2-20: 30-60 become. 11. The method according to any one of claims 4-10, characterized in that at least one of the monomers used has the formula Ia
wherein R ¹ and R ^{2 have} the meaning given in claim 5, R ^{10 represents} a direct chemical bond or an alkyl, alkenyl, aralkyl or aryl radical which may be unbranched or branched and may optionally contain or / and be substituted by heteroatoms and
C represents a polyether radical. 12. The method according to any one of the preceding claims, characterized, that the manufacture of the nanoparticles by implementing Monomers in the presence of at least one block copolymer he follows. 13. The method according to claim 12, characterized,  that as a block copolymer a polystyrene-polyethylene glycol Block copolymer is used. 14. The method according to any one of claims 4-13, characterized, that the manufacture of the nanoparticles under Emulsion polymerization conditions is carried out. 15. The method according to claim 14, characterized, that an emulsifier is added during the emulsion polymerization and is removed after the production of the nanoparticles. 16. The method according to any one of the preceding claims, characterized, that the reversible crosslinking of the nanoparticles in step (b) by a Diels-Alder reaction or / and through interactions nucleophilic groups on the nanoparticles with an aluminoxane is effected. 17. The method according to claim 16, characterized, that the nanoparticles are functionalized by implementation with a cyclopentadienyl compound and / or a fulvene compound. 18. The method according to any one of the preceding claims, characterized, that the surface of the nanoparticles continues to contain hydroxyl groups is functionalized. 19. The method according to any one of the preceding claims, characterized in that the carrier particles are implemented with a for further functionalization

• a) aluminoxane,
• b) aluminum alkyl,
• c) polyether or / and
• d) a boron compound.

20. The method according to claim 19, characterized, that a methylaluminoxane is used as the aluminoxane. 21. The method according to claim 19, characterized, that tri (pentafluorophenyl) boron is used as the boron compound. 22. A method for producing a supported polymerization catalyst, characterized in that, in addition to steps (a) and (b) according to one of claims 1-21, it further comprises a step:

• a) adding a polymerization catalyst or a precursor to the support material.

23. The method according to claim 22, characterized, that a transition metal polymerization catalyst is used. 24. The method according to any one of claims 22 or 23, characterized, that a metallocene catalyst is used. 25. The method according to any one of claims 22 to 24,  characterized, that the polymerization catalyst is non-covalently attached to the Carrier material is bound. 26. The method according to any one of claims 22 to 25, characterized, that the polymerization catalyst together with a Aluminum compound is applied to the carrier. 27. Fragmentable support for polymerization catalysts available by a method according to any one of claims 1-21. 28. Fragmentable carrier according to claim 27, characterized, that it is formed from irreversibly cross-linked nanoparticles that are reversibly cross-linked to carrier microparticles. 29. Supported catalyst, obtainable by a process according to a of claims 22-26. 30. Process for the polymerization of olefins in the presence of a Fragmentable carrier according to claim 27 or claim 28 or / and a supported catalyst according to claim 29. 31. A polyolefin obtainable by a process according to claim 30.