DE102005048327A1 - Degradation of nitrile rubbers by metathesis involves subjecting the rubber to a metathesis reaction in presence of a ruthenium- or osmium-based catalyst containing imidazolidine ligand and carbene ligand containing phosphonium radical - Google Patents

Abstract

Degradation of nitrile rubbers by metathesis involves: subjecting the nitrile rubber to a metathesis reaction in the presence of a ruthenium- or osmium-based catalyst containing an imidazolidine ligand and a carbene ligand containing a phosphonium radical. Degradation of nitrile rubbers by metathesis involves: subjecting the nitrile rubber to a metathesis reaction in the presence of a catalyst of formula (I). M : ruthenium or osmium; X 1 and X 2anionic ligands; R 1-R 3organic radicals; Im : optionally substituted imidazolidine radical; A : an anion. [Image].

Description

The The present invention relates to novel ruthenium or osmium based Catalysts, a process for their preparation and their use for the metathesis degradation of nitrile rubber.

hydrogenated Nitrile rubber, abbreviated also referred to as "HNBR" is by hydrogenation of nitrile rubber, also abbreviated to "NBR".

Under Nitrile rubber is understood to mean rubbers in which it is to copolymers of at least one unsaturated nitrile and at least a conjugated diene and possibly other comonomers.

hydrogenated Nitrile rubber is a special rubber that has very good heat resistance, excellent resistance against ozone and chemicals as well as an excellent oil resistance features.

The aforementioned physical and chemical properties of the HNBR go along with very good mechanical properties, in particular a high abrasion resistance. For this reason, HNBR has wide use found in a wide variety of applications. For example, HNBR is used used for Seals, hoses, Belts and damping elements in the automotive sector, furthermore for Stators, borehole seals and valve seals in the field of oil extraction as well as for numerous parts of the electrical industry, engineering and shipbuilding.

Commercially available HNBR types on the market usually have a Mooney viscosity (ML 1 + 4 @ 100 ° C) in the range of 55 to 105, which is a weight average molecular weight M _w (determination method: gel permeation chromatography (GPC) versus polystyrene equivalents) in the range from about 200,000 to 500,000. The polydispersity indices PDI to be measured (PDI = M _w / M _n , where M _{w represents} the weight average and M _n the number average molecular weight), which provide information about the breadth of the molecular weight distribution, are often at a value of 3 or more. The residual double bond content is usually in a range of 1 to 18% (determined by IR spectroscopy).

Of the Processability of HNBR is strong due to the relatively high Mooney viscosity Restrictions imposed. For many Applications would be a HNBR type desirable, which has a lower molecular weight and thus a lower Mooney viscosity. This would significantly improve processability.

In In the past, numerous attempts have been made to increase the chain length of To shorten HNBR by degradation. This degradation was carried out for example via the mechanical way so-called mastication, z. B. on a rolling mill. In principle, it is possible also the chemical degradation by reaction with strong acids. This However, chemical degradation has the disadvantage of having functional groups like carboxylic acid and ester groups in the molecule be installed and in addition the microstructure of the polymer is substantially changed. All these changes bring disadvantages for the applications with it.

The production of HNBR with low molecular weights, corresponding to a Mooney viscosity (ML 1 + 4 at 100 ° C) in a range of less than 55 or a number average molecular weight of M _n <200,000 g / mol, is not possible by means of established production processes on the one hand in the hydrogenation of NBR a sudden increase in the Mooney viscosity and on the other hand, the molecular weight of the NBR feedstock to be used for the hydrogenation can not be arbitrarily reduced, otherwise the work-up in the available large-scale facilities because of excessive tackiness is no longer possible , The lowest Mooney viscosity of a NBR feedstocks, which can be processed without difficulty in an established large-scale plant, is about 30 Mooney units (ML 1 + 4 at 100 ° C). The Mooney viscosity of the hydrogenated nitrile rubber obtained with such NBR feedstock is of the order of 55 Mooney units (ML 1 + 4 at 100 ° C).

In the known art, this problem is solved by determining the molecular weight of the nitrile rubber before hydrogenation by degradation to Mooney values (ML 1 + 4 at 100 ° C) of less than 30 Mooney units or a number average molecular weight of M _n < 70,000 g / mol reduced. The degradation of the molecular weight is achieved here by metathesis, which is usually metathesis at this tion low molecular weight 1-olefins are added. The metathesis reaction is expediently carried out in the same solvent as the hydrogenation reaction (in situ), so that the degraded NBR feedstock does not have to be isolated from the solvent after completion of the degradation reaction before it is subjected to the subsequent hydrogenation. Metathesis catalysts which are tolerant of polar groups, particularly nitrile groups, are used to catalyze the metathesis degradation reaction.

described For example, this production of low Mooney HNBRs in WO-A-02/100941 and WO-A-02/100905. In WO-A-02/100905 describes a process which involves the degradation of nitrile rubber starting polymers by olefin metathesis and subsequent hydrogenation. in this connection is a nitrile rubber in a first step in the presence of a Co-olefins and a special complex catalyst on osmium, Ruthenium, molybdenum or tungsten-based reacted and hydrogenated in a second step. Available are according to WO-A-02/100941 in this way hydrogenated nitrile rubbers with a weight average molecular weight (Mw) in the range of 30,000 to 250,000, one Mooney Viscosity (ML 1 + 4 @ 100 ° C) in the range of 3 to 50 and a polydispersity index PDI of less than 2.5.

worin M für Osmium oder Ruthenium steht, R und R¹ organische Reste mit großer struktureller Variationsbreite darstellen, X und X₁ anionische Liganden sind und L sowie L₁ neutrale Elektronen-Donoren darstellen.Metathesis catalysts are known inter alia from WO-A-96104289 and WO-A-97/06185. They have the following basic structure:

wherein M is osmium or ruthenium, R and R ^{1 are} organic radicals having a large structural variation, X and X _{1 are} anionic ligands, and L and L _{1 are} neutral electron donors.

such Catalysts are suitable for Ring-closing metathesis (RCM), cross-metathesis (CM), and ring-opening metathesis (ROMP). For the implementation The degradation of nitrile rubber are the catalysts mentioned but not necessarily suitable.

With Some catalysts from the group of "Grubbs (I) catalysts" succeed in carrying out the metathesis of nitrile rubber. It is suitable, e.g. a ruthenium catalyst with certain substituent patterns, e.g. the following Catalyst bis (tricyclohexylphosphine) benzylidene ruthenium dichloride.

Grubbs (I) Katalysator

Grubbs (I) catalyst

To In hydrogenation, the rubbers have a very lower molecular weight and a narrow molecular weight distribution (WO-A-02/100941, WO-A-03/002613).

Out US 2004/0110888 A1 are also vulcanizates based on these low molecular weight HNBR rubbers known.

US 2004/0127647 A1 describes blends based on low molecular weight HNBR rubbers with bimodal or multimodal molecular weight distribution as well as vulcanizates of these rubbers.

WO-A-00/71554 further discloses a group of catalysts known in the art as "Grubbs (II) catalysts." Using such a "Grubbs (II) catalyst" such as 1,3-bis ( 2,4,6-trimethylphenyl) -2-imidazolidenylidene) (tricyclohexylphosphine) ruthenium (phenylmethylene) dichloride for NBR metathesis, this is possible even without the use of a co-olefin. After the subsequent hydrogenation, which is carried out in-situ, the hydrogenated nitrile rubber has lower molecular weights and a narrower molecular weight distribution (PDI) than when using Grubbs (I) type catalysts (US-A-2004/0132891).

Grubbs (II) Katalysator

Grubbs (II) catalyst

The Use of Grubbs (II) catalyst degraded nitrile rubbers for adhesive compositions are described for example in US 2004/0132906-A1.

The mentioned method for Metathes degradation of nitrile rubber and the therefor used catalysts have the disadvantage that solutions of these Catalysts, especially in the presence of atmospheric oxygen, unstable are and always have to be freshly prepared.

Piers (I) Katalysator wobei R beispielsweise für iso-Propyl- oder Cyclohexyl-Reste steht und A ein Anion ist.Also known in the art are catalysts which are referred to below as Piers (I) catalysts and have the following structure (see, for example, Angew. Chem. Int. Ed. 2004, 43, 6161-6165):

Piers (I) catalyst wherein R is, for example, iso-propyl or cyclohexyl radicals and A is an anion.

Out However, our own investigations have shown that such piers (I) Catalysts in NBR metathesis do not degrade the nitrile rubber to lead, but exclusively to a NBR gel. As a result, the nitrile rubber is unusable.

outgoing Therefore, the task of the prior art was a catalyst to disposal to provide a breakdown of nitrile rubber, without a gag being observed, and the one besides improved storage stability in solution having.

Surprisingly could solve this task be replaced by new special catalysts containing an imidazolidine ligand and at the same time a carbene ligand with a phosphine residue wear.

wobei
M Ruthenium oder Osmium bedeutet,
X¹ und X² gleich oder verschieden sein können und anionische Liganden darstellen,
R¹, R² und R³ gleich oder verschieden sind und organische Reste darstellen,
Im einen gegebenenfalls substituierten Imidazolidinrest darstellt und
A ein Anion darstellt.The invention thus provides a catalyst of the general formula (I)

in which
M is ruthenium or osmium,
X ¹ and X ^{2 may be the} same or different and represent anionic ligands,
R ¹ , R ² and R ^{3 are the} same or different and represent organic radicals,
In an optionally substituted Imidazolidinrest represents and
A represents an anion.

These Catalysts of general formula (I) with an imidazolidine ligand and a carbene ligand having a phosphine moiety hitherto unknown from the prior art. They let themselves successfully use for metathesis degradation, i. it will be a degradation of nitrile rubber, without any gelling being observed becomes. This is even more surprising than for the Piers (I) catalysts described above no suitability for the use for metathesis degradation of nitrile rubbers are found could. About that In addition, form the catalysts of the invention also increased if necessary Temperatures a stable solution in the solvents typically used, in particular in chlorobenzene. A discoloration of catalyst solutions for a longer time Standing or elevated Temperature, which is usually suggesting deactivation or decomposition could not be observed become.

X ¹ and X ² :

In the catalysts of general formula (I) X ¹ and X ^{2 may be} identical or different and, for example, hydrogen, halogen, pseudohalogen, C ₁ -C ₂₀ alkyl, aryl, C ₁ -C ₂₀ alkoxy, aryloxy, C ₃ -C _20- alkyldiketonate, aryldiketonate, C ₁ -C ₂₀ -carboxylate, arylsulfonate, C ₁ -C ₂₀ -alkylsulfonate, C ₁ -C ₂₀ -alkylthiol, arylthiol, C ₁ -C ₂₀ -alkylsulfonyl or C ₁ -C ₂₀ -alkylsulfinyl Represent remnants.

The abovementioned radicals as meanings of X ¹ and X ² can furthermore be substituted by one or more further radicals, for example by halogen, preferably fluorine, C ₁ -C ₁₀ -alkyl, C ₁ -C ₁₀ -alkoxy or aryl radicals, also the latter radicals may optionally in turn be substituted by one or more substituents selected from the group comprising halogen, preferably fluorine, C ₁ -C ₅ -alkyl, C ₁ -C ₅ -alkoxy and phenyl.

In a preferred embodiment, X and X ^{1 are} halogen, benzoate, C ₁ -C ₅ -carboxylate, C ₁ -C ₅ -alkyl, phenoxy, C ₁ -C ₅ -alkoxy, C ₁ -C ₅ -alkylthiol, arylthiol, aryl and C ₁ -C ₅ alkyl sulfonate. In a particularly preferred embodiment, X and X ^{1 are} both simultaneously halo, CF ₃ COO, CH ₃ COO, CFH ₂ COO, (CH ₃ ) ₃ CO, (CF ₃ ) ₂ (CH ₃ ) CO, (CF ₃ ) (CH ₃ ) ₂ CO, PhO, MeO, EtO, tosylate, mesylate or trifluoromethanesulfonate. In particular, X and X ^{1 are} simultaneously chlorine.

P (R ¹ R ² R ³ ):

In the general formula (I), the radicals R ¹ , R ² and R ³ in the radical P (R ¹ R ² R ³ ) are identical or different and may be straight-chain or branched C ₁ -C ₃₀ -alkyl, C ₅ -C ₃₀ -Cylcoalkyl or aryl, wherein the C ₁ -C ₃₀ -alkyl radicals may optionally be interrupted by one or more double or triple bonds or one or more heteroatoms, preferably oxygen or nitrogen.

As the radical P (R ¹ R ² R ³ ), for example, triphenylphosphine, tricyclohexylphosphine, tricyclopentylphosphine, triisopropylphosphine, tri (o-tolyl) phosphine, tri (o-xylyl) phosphine and trimesitylphosphine are suitable for the catalysts of general formula (I) according to the invention.

In the:

wobei
R⁴, R⁵, R⁶, R⁷ gleich oder verschieden sein können und Wasserstoff, geradkettiges oder verzweigtes, cyclisches oder acyclisches C₁-C₂₀-Alkyl, C₂-C₂₀ Alkenyl, C₂-C₂₀-Alkinyl, Aryl, C₁-C₂₀-Carboxylat, C₁-C₂₀-Alkoxy, C₂-C₂₀-Alkenyloxy, C₂-C₂₀-Alkinyloxy, Aryloxy, C₂-C₂₀-Alkoxycarbonyl, C₁-C₂₀-Akylthio, Arylthio, C₁-C₂₀-Alkylsulfonyl, C₁-C₂₀-Alkylsulfonat, C₆-C₂₀-Arylsulfonat und C₁-C₂₀-Alkylsulfinyl bedeuten.The imidazolidine residue (Im) in the general formula (I) usually has a structure of the general formulas (IIa) or (IIb)

in which
R ⁴ , R ⁵ , R ⁶ , R ^{7 may be} identical or different and are hydrogen, straight-chain or branched, cyclic or acyclic C ₁ -C ₂₀ -alkyl, C ₂ -C ₂₀ -alkenyl, C ₂ -C ₂₀ -alkynyl, aryl , C ₁ -C ₂₀ -carboxylate, C ₁ -C ₂₀ -alkoxy, C ₂ -C ₂₀ -alkenyloxy, C ₂ -C ₂₀ -alkynyloxy, aryloxy, C ₂ -C ₂₀ -alkoxycarbonyl, C ₁ -C ₂₀ -alkylthio , Arylthio, C ₁ -C ₂₀ -alkylsulfonyl, C ₁ -C ₂₀ -alkylsulfonate, C ₆ -C ₂₀ -arylsulfonate and C ₁ -C ₂₀ -alkylsulfinyl.

Optionally, one or more of R ⁴ , R ⁵ , R ⁶ , R ⁷ independently of one another by one or more substituents, preferably straight-chain or branched, cyclic or acyclic C ₁ -C ₁₀ alkyl, C ₁ -C ₁₀ alkoxy or Aryl substituted, these aforementioned substituents may in turn be substituted by one or more radicals, preferably selected from the group halogen, C ₁ -C ₅ alkyl, C ₁ -C ₅ alkoxy and phenyl.

In a preferred embodiment of the catalysts according to the invention, R ⁴ and R ⁵ independently of one another are hydrogen, aryl, particularly preferably phenyl, straight-chain or branched C ₁ -C ₁₀ -alkyl, particularly preferably propyl or butyl, or together form a cycloalkyl or aryl radical in which all the abovementioned radicals may, in turn, optionally be substituted by one or more further radicals selected from the group comprising straight-chain or branched C ₁ -C ₁₀ -alkyl, C ₁ -C ₁₀ -alkoxy, aryl and a functional group selected from the group of hydroxy, thiol, thioether, ketone, aldehyde, ester, ether, amine, imine, amide, nitro, carboxylic acid, disulfide, carbonate, isocyanate, carbodiimide, carboalkoxy, carbamate and halogen.

In a preferred embodiment of the catalysts according to the invention, the radicals R ⁶ and R ^{7 are} identical and different and are straight-chain or branched C ₁ -C ₁₀ -alkyl, particularly preferably i-propyl or neopentyl, aryl, particularly preferably phenyl, C ₁ -C ₁₀ Alkyl sulfonate, more preferably methanesulfonate, or C ₆ -C ₁₀ aryl sulfonate, more preferably p-toluenesulfonate. Optionally, the abovementioned radicals are substituted as meanings of R ⁶ and R ⁷ by one or more further radicals selected from the group comprising straight-chain or branched C ₁ -C ₅ -alkyl, in particular methyl, C ₁ -C ₅ -alkoxy, aryl or a functional group selected from the group of hydroxy, thiol, thioether, ketone, aldehyde, ester, ether, amine, imine, amide, nitro, carboxylic acid, disulfide, carbonate, isocyanate, carbodiimide, carboalkoxy, carbamate and halogen. The radicals R ⁶ and R ⁷ are particularly preferably identical or different and are i-propyl, neopentyl or adamantyl.

Particularly preferred imidazolidine radicals (Im) have the following structures (IIIa-f):

A:

In of general formula (I) is A is an anion, preferably from Group of halides, pseudohalides, complex anions and from the group of non-coordinating anions.

A For example, nitrate, fluorosulfonate or trifluoromethanesulfonate (Triflate).

When Halide may mean A fluoride, chloride, bromide or iodide.

When Pseudohalide may include, for example, cyanide, rhodanide, azide, cyanurate and thiocyanurate.

A may also contain a complex anion such as perchlorate, tetrafluoroborate, Tetrafluoroaluminate, hexafluorophosphate, hexafluoroarsenate, hexafluoroantimonate or hexachloroantimonate.

A may also be a noncoordinating anion such as tetrakis [pentafluorophenyl] borate, Pentakis [pentafluorophenyl] phosphate, tetrakis [3,5-trifluoromethylphenyl] borate, Pentakis [3,5-trifluoromethylphenyl] phosphate, pentakis [pentafluorophenyl] cyclohexadienyl anion or bis ((tris-pentafluorophenyl) boron) cyanide.

wobei
R¹, R², R³ geradkettiges oder verzweigtes C₁-C₃₀-Alkyl, C₅-C₁₀ Cylcoalkyl oder Aryl darstellen, wobei die C₁-C₃₀-Alkylreste gegebenenfalls durch ein oder mehrere Doppel- oder Dreifachbindungen oder auch ein oder mehrere Heteroatome, bevorzugt Sauerstoff oder Stickstoff, unterbrochen sein können und
A die für die allgemeine Formel (I) genannten Bedeutungen besitzt.Particularly preferred catalysts are those of the following structures (IVa-c):

in which
R ¹ , R ² , R ^{3 represent} straight-chain or branched C ₁ -C ₃₀ -alkyl, C ₅ -C ₁₀ -cycloalkyl or aryl, where the C ₁ -C ₃₀ -alkyl radicals are optionally substituted by one or more double or triple bonds or also a or more heteroatoms, preferably oxygen or nitrogen, may be interrupted and
A has the meanings given for the general formula (I).

Very particular preference is given to catalysts of the general formulas (IVa-c),
in which
the radical P (R ¹ R ² R ³ ) triisopropylphosphine, triphenylphosphine, Tricyclohexylphoshin, tricyclopentylphosphine, tri (o-tolyl) phosphine, tri (o-xylyl) phosphine or Trimesitylphosphin means
and
A is bromide, tetrafluoroborate, tetrakis (3,5-trifluoromethylphenyl) borate, tetrakis [pentafluorophenyl] borate or bis ((tris-pentafluorophenyl) boron) cyanide.

These Catalysts of the general formula (I) are outstandingly suitable for use in the metathesis degradation of nitrile rubber.

object The invention thus further provides a method for metathesis degradation of nitrile rubbers, wherein a nitrile rubber of a metathesis reaction in the presence of a catalyst of general formula (I) subjects.

Reaction conditions of Metathesis:

The Amount of for the metathesis catalyst used of the general formula (I) depends on the nature and catalytic activity of the particular catalyst from. The amount of catalyst used, based on the used Nitrile rubber, is 5 to 1,000 ppm noble metal, preferably from 10-500 ppm, in particular of 25-250 ppm.

The NBR metathesis is usually carried out in the presence of a co-olefin, which is preferably a straight or branched C ₂ -C ₁₆ olefin. Suitable examples are ethylene, propylene, isobutene, styrene, 1-hexene or 1-octene. Preference is given to using 1-hexene or 1-octene. If this co-olefin is liquid (such as 1-hexene), the amount of the co-olefin is preferably in a range of 0.2-20 wt .-% based on the NBR used. If the co-olefin is a gas, such as ethylene, the amount of co-olefin is chosen so that a pressure in the range of 1 × 10 ⁵ Pa-1 × 10 ⁷ Pa is established in the reaction vessel, preferably a pressure in the range from 5.2 × 10 ⁵ Pa to 4 × 10 ⁶ Pa.

The Metathesis reaction can be carried out in a suitable solvent which does not deactivate the catalyst used and the reaction also not negatively affected in any other way. preferred solvent include, but are not limited to, dichloromethane, benzene, toluene, methyl ethyl ketone, Acetone, tetrahydrofuran, tetrahydropyran, dioxane and cyclohexane. The most preferred solvent is chlorobenzene. In some cases, if the co-olefin itself as a solvent can function, e.g. at 1-witches, can also on the addition of a additional additional solvent be waived.

The Concentration of the nitrile rubber used in the reaction mixture Metathesis is not critical, but it is natural too Note that the reaction is not due to a much too high viscosity of the reaction mixture and negatively affected the associated mixing problems should be. Preferably, the concentration of NBR is in the Reaction mixture in the range of 1 to 20 wt .-%, more preferably in the range of 5 to 15 wt .-%, based on the total reaction mixture.

Of the Metathesis degradation is common at a temperature in the range of 20 ° C to 150 ° C, preferably in the range of From 30 to 100 ° C, especially in the range of 50 to 90 ° C.

The Reaction time depends depends on a number of factors, for example the type of NBR, the type of catalyst, the catalyst concentration used and the reaction temperature. Typically, the reaction is within ended by three hours under normal conditions. The progress the metathesis can be monitored by standard analysis, e.g. by GPC or determination of viscosity.

nitrile rubbers:

When Nitrile Rubbers ("NBR") can be used in the metathesis reaction polymers are used which repeating units at least one conjugated diene, at least one α, β-unsaturated Nitrile and optionally one or more further copolymerizable Contain monomers.

The conjugated diene can be of any nature. Preference is given to using (C ₄ -C ₆ ) conjugated dienes. Particular preference is given to 1,3-butadiene, isoprene, 2,3-dimethylbutadiene, piperylene or mixtures thereof. Particular preference is given to 1,3-butadiene and isoprene or mixtures thereof. Very particular preference is given to 1,3-butadiene.

As α, β-unsaturated nitrile, any known α, β-unsaturated nitrile can be used, preferred are (C ₃ -C ₅ ) -α, β-unsaturated nitriles such as acrylonitrile, methacrylonitrile, ethacrylonitrile or mixtures thereof. Particularly preferred is acrylonitrile.

a particularly preferred nitrile rubber thus constitutes a copolymer of acrylonitrile and 1,3-butadiene represents.

In addition, other monomers known to those skilled in the art may be used, for example α, β-unsaturated carboxylic acids or their esters. Preferred are fumaric acid, maleic acid, acrylic acid, methacrylic acid as acids and their esters butyl acrylate, butyl methacrylate, ethylhexyl acrylate and ethylhexyl methacrylate. Other monomers that can be used are unsaturated dicarboxylic acids or derivatives thereof, such as esters or amides. Preference is given to methacrylic acid, fumaric acid, butyl acrylate and 2-ethylhexy lacrylat.

The Proportions of conjugated diene and α, β-unsaturated Nitrile in the NBR polymers to be used can in vary widely. The proportion of or the sum of the conjugated Serve is usually in the range of 40 to 90% by weight and preferably in the range of 65 to 75 wt .-%, based on the total polymer. The share of or the sum of the α, β-unsaturated Nitriles are usually at 9.9 to 60 wt .-%, preferably at 15 to 50 wt .-%, based on the total polymer. The additional Monomers can in amounts of 0.1 to 40 wt .-%, preferably 1 to 30 wt .-%, based to the total polymer. The proportions of all monomers sum up each at 100 wt .-% on.

The Preparation of the nitrile rubbers by polymerization of the aforementioned Monomers are sufficient for the person skilled in the art known and in the literature (e.g., Houben-Weyl, Methoden der Organischen Chemistry Bd.14 / 1, Georg Thieme Verlag Stuttgart 1961) extensive described.

The nitrile rubbers used for the metathesis have a Mooney viscosity (ML 1 + 4 @ 100 ° C) in the range of 30 to 70, preferably 30 to 50. This corresponds to a weight average molecular weight M _w in the range of 200,000-500,000, preferably in Range of 200,000-400,000. The nitrile rubbers used also have a polydispersity PDI = M _w / M _n , where M _{n represents} the number average molecular weight, in the range of 2.0-6.0, and preferably in the range of 2.0-4.0.

The Determination of the Mooney viscosity takes place according to ASTM standard D 1646.

Degraded nitrile rubbers:

The nitrile rubbers obtained by the metathesis process of the present invention have a Mooney viscosity (ML 1 + 4 @ 100 ° C) in the range of 5-30, preferably 5-20. This corresponds to a weight average molecular weight M _w in the range of 10,000-200,000 , preferably in the range of 10.00-150.000. The nitrile rubbers obtained further have a polydispersity PDI = M _w / M _n , where M _{n is} the number average molecular weight, in the range 1.5-4.0, preferably in the range of 1.7-3.

hydrogenation:

At the inventive method the metathesis degradation may degrade a hydrogenation of the obtained Connect nitrile rubbers. This can be done in the manner known to those skilled in the art.

It is possible, the hydrogenation using homogeneous or heterogeneous hydrogenation catalysts perform. It is also possible to carry out the hydrogenation in situ, i.e. in the same reaction vessel, in the previously also the metathesis degradation and without need to isolate the degraded nitrile rubber. The hydrogenation catalyst is simply added to the reaction vessel.

For example, the reaction with hydrogen is suitable using homogeneous catalysts, such as, for example, the catalyst known as "Wilkinson" ((PPh ₃ ) ₃ RhCl) and tetrakis (triphenylphosphine) rhodium hydride or others.

method for the hydrogenation of nitrile rubber are known. Rhodium, ruthenium or titanium become common used as catalysts, but also platinum, iridium, palladium, Rhenium, ruthenium, osmium, cobalt or copper either as metal, or preferably used in the form of metal compounds can (See, for example, US-A-3,700,637, DE-A-2,539,132, EP-A-0 134 023, DE-OS-35 41,689, DE-OS 35 40 918, EP-A-0 298 386, DE-OS 35 29 252, DE-OS-34 33,392, US-A-4,464,515 and US-A-4,503,196).

suitable Catalysts and solvents for one Homogeneous phase hydrogenation is described below and are also known from DE-A-25 39132 and EP-A-0471250

The selective hydrogenation can be achieved, for example, in the presence of a rhodium- or ruthenium-containing catalyst. It is possible, for example, to use a catalyst of the general formula (R ¹ _m B) ₁ MX _n , wherein M is ruthenium or rhodium, R ^{1 are the} same or different and represent a C ₁ -C ₈ alkyl group, a C ₄ -C ₈ cycloalkyl group, a C ₆ -C ₁₅ aryl group or a C ₇ -C ₁₅ aralkyl group. B is phosphorus, arsenic, sulfur or a sulfoxide group S = O, X is hydrogen or an anion, preferably halogen and more preferably chlorine or bromine, l is 2,3 or 4, m is 2 or 3 and n is 1, 2 or 3, preferably 1 or 3. Preferred catalysts are tris (triphenylphosphine) rhodium (I) chloride, tris (triphenylphosphine) rhodium (III) chloride and tris (dimethyl sulfoxide) rhodium (III) chloride and tetrakis ( triphenylphosphine) rhodium hydride of the formula (C ₆ H ₅ ) ₃ P) ₄ RhH and the corresponding compounds in which the triphenylphosphine has been wholly or partly replaced by tricyclohexylphosphine. The catalyst can be used in small quantities. An amount in the range of 0.01-1 wt .-%, preferably in the range of 0.03-0.5 wt .-% and particularly preferably in the range of 0.1-0.3 wt .-% based on the Weight of the polymer are suitable.

Usually it makes sense to use the catalyst together with a co-catalyst which is a ligand of the formula R ¹ _m B, wherein R ¹ , m and B have the meanings given above. Preferably m is 3, B is phosphorus and the radicals R ¹ may be the same or different. Preference is given to co-catalysts with trialkyl, tricycloalkyl, triaryl, triaralkyl, diaryl-monoalkyl, diaryl-monocycloalkyl, dialkyl-monoaryl, dialkyl-monocycloalkyl, dicycloalkyl-monoaryl or dicyclalkyl-monoaryl radicals.

Examples Co-catalysts can be found, for example, in US-A-4,631,315. Preferred co-catalyst is triphenylphosphine. The co-catalyst is preferred in amounts in a range of 0.3-5% by weight, preferably in the range of 0.5-4 % By weight, based on the weight of the nitrile rubber to be hydrogenated. Also preferred is the weight ratio of the rhodium-containing Catalyst to co-catalyst in the range of 1: 3 to 1:55, preferably in the range of 1: 5 to 1:45. Based on 100 parts by weight of the hydrogenating nitrile rubbers are suitably 0.1 to 33 Parts by weight of the co-catalyst, preferably 0.5 to 20 and completely particularly preferably 1 to 5 parts by weight, in particular more than 2 but less than 5 parts by weight of co-catalyst based on 100 Parts by weight of the nitrile rubber to be hydrogenated used.

The practical implementation This hydrogenation is well known to those skilled in the art from US-A-6,683,136. It usually happens by passing the nitrile rubber to be hydrogenated in a solvent such as toluene or monochlorobenzene at 100-150 ° C and a pressure of 50-150 bar for 2-10 h with Hydrogen applied.

Under In the context of this invention, hydrogenation is a reaction of the Starting nitrile rubber existing Double bonds at least 50%, preferably 70-100%, particularly preferred 80-100%, understood.

at The use of heterogeneous catalysts is usually to be carried Catalysts based on palladium supported z. On carbon, silica, calciumxoid, Barium sulfate etc.

Upon completion of the hydrogenation, a hydrogenated nitrile rubber having a Mooney viscosity (ML 1 + 4 @ 100 ° C), measured in accordance with ASTM Standard D 1646, in the range of 10-50, preferably 10-30. This corresponds to a weight average molecular weight M _w in the range of 20.00-400,000 g / mol, preferably in the range of 20,000-200,000. The hydrogenated nitrile rubbers obtained further have a polydispersity PDI = M _w / M _n , where M _{n is} the number average molecular weight, in the range of 1-5 and preferably in the range of 1.5-3.

I Synthesis of catalysts according to the invention

• • [dichloro (1,3-dimesityldihydroimidazolylidene) (tricyclohexylphosphoniocarben)] tetrafluoroborate (2) in B2;
• • [dichloro (1,3-dimesityldihydroimidazolylidene) (tricyclohexylphosphoniocarben)] [Tetrakis (3,5-trifluoromethylphenyl) borate] (3) in B3
• • [dichloro (4,5-dibutyl-1,3-dimesityldihydroimidazolylidene) (tricyclohexylphosphonio carbene)] tetrafluoroborate (6) in B8

B1 Carbido (dichloro) -1,3-dimesityldihydroimidazolylidene (tricyclohexylphosphine) ruthenium (1)

• ¹H NMR (300 MHz, CDCl₃): δ 6.95 (s, 2H), 6.89 (s, 2H), 4.07 (m, 4H), 2.53 (s, 6H), 2.49 (s, 6H), 2.31 (breit s, 3H), 2.29 (s, 3H), 2.24 (s, 3H), 1.88, 1.62, 1.13 (alle m, 30H).
• ³¹P NMR (121 MHz, CDCl₃): δ 34.7 (s).

Into a 25 ml Schlenk flask were charged (1,3-dimesityldihydroimidazolylidene) (PCy ₃ ) Cl ₂ Ru = CHPh (0.42 g, 0.5 mmol) and diethyl trans-3-methylene-1,2-cyclopropanedicarboxylate (0.10 g, 0.5 mmol). Under nitrogen as inert gas, dry CH ₂ Cl ₂ (5 ml) was added and the red-brown solution was stirred for 12 hours. Thereafter, the solvent of the resulting orange-brown solution was removed under high vacuum. Under nitrogen, the brown residue was taken up in hexane (2 ml), stirred for 1 hour and then filtered. Washing the residue twice with hexane gave carbido (dichloro) -1,3-dimesityldihydroimidazolylidene (tricyclohexylphosphine) ruthenium (1) as a tan solid (0.23 g, 60%).

• ¹ H NMR (300 MHz, CDCl ₃ ): δ 6.95 (s, 2H), 6.89 (s, 2H), 4.07 (m, 4H), 2.53 (s, 6H), 2.49 (s, 6H), 2.31 (broad s, 3H), 2.29 (s, 3H), 2.24 (s, 3H), 1.88, 1.62, 1.13 (all m, 30H).
• ³¹ P NMR (121 MHz, CDCl _3): δ 34.7 (s).

B2 [Dichloro (1,3-dimesityldihydroimidazolylidene) (tricyclohexylphosphoniocarben)] tetrafluoroborate (2)

All glassware were in an oven at 160 ° C dried.

• ¹H NMR (300 MHz, CD₂Cl₂): δ 17.86 (d, J = 36 Hz, 1H), 7.11 (s, 4H), 4.21 (s, 4H), 2.40 (s, 6H), 2.38 (s, 12H), 2.34 (breit s, 3H), 1.82, 1.25 (all m, 30H).

In a 25 ml Schlenk vessel, compound (1) from example B1 (0.15 g, 0.195 mmol) was initially introduced under nitrogen as protective gas. For this purpose, 10 ml of dry CH ₂ Cl _{2 were} condensed in vacuo and then the reaction mixture was warmed to room temperature. [H (Et ₂ O) ₂ ] BF ₄ (0.027 mL, 0.195 mmol) was added via syringe and the color of the solution turned green-brown. It was stirred for 2 hours and then the solvent was removed in an oil pump vacuum. The oily residue was extracted under nitrogen with 2 ml of hexane for 1 hour and filtered. After washing twice more with hexane, [dichloro (1,3-dimesityldihydroimidazolylidene) (tricyclohexylphosphoniocarben)] tetrafluoroborate (2) was obtained as a green-brown microcrystalline solid (0.15 g, 90%).

• ¹ H NMR (300 MHz, CD ₂ Cl ₂ ): δ 17.86 (d, J = 36 Hz, 1H), 7.11 (s, 4H), 4.21 (s, 4H), 2.40 (s, 6H), 2.38 (s , 12H), 2.34 (broad s, 3H), 1.82, 1.25 (all m, 30H).

B3 [dichloro (1,3-dimesityldihydroimidazolylidene) (tricyclohexylphosphoniocarben)] [tetrakis (3,5-trifluoromethylphenyl) borate] (3)

All glassware were in an oven at 160 ° C dried.

• ¹H NMR (300 MHz, CD₂Cl₂): δ 18.08 (d, J = 38 Hz, 1H), 7.72 (m, 8H), 7.56 (s, 4H), 7.07 (s, 4H), 4.15 (s, 4H), 2.37 (s, 18H), 2.33 (breit s, 3H), 1.80, 1.24 (alle m, 30H).
• ³¹P NMR (121 MHz, CDCl₃): δ 51.2 (breit).
• Theoretische Gehalte für C₇₂H₇₂BCl₂F₂₄N₂PRu: C: 52.89%, H: 4.44%, N: 1.71%
• Analytisch bestimmt: C: 52.92%, H: 4.35%, N: 1.73%.

In a 25 ml Schlenk vessel, Compound 1 from Example B1 (0.231 g, 0.3 mmol) and [H (Et ₂ O) ₂ ] [B [3,5- (CF ₃ ) ₂ C ₆ H ₃ ] ₄ ] (0.304 ml 0.3 mmol). In vacuo, dry CH ₂ Cl ₂ (15 ml) was condensed in and the mixture was then warmed to room temperature. After stirring for 2 hours, the solvent was removed in an oil pump vacuum. The residual oil was extracted with hexane under nitrogen for 1 hour and the supernatant decanted. The washing with hexane was repeated once. It was [dichloro (1,3-dimesityldihydroimidazolyliden) (tricyclohexylphosphoniocarben)] [tetrakis (3,5-trifluoromethyl phenyl) borate] (3) as a greenish-brown solid obtained (0.46 g, 94%).

• ¹ H NMR (300 MHz, CD ₂ Cl ₂ ): δ 18.08 (d, J = 38 Hz, 1H), 7.72 (m, 8H), 7.56 (s, 4H), 7.07 (s, 4H), 4.15 (s , 4H), 2.37 (s, 18H), 2.33 (broad s, 3H), 1.80, 1.24 (all m, 30H).
• ³¹ P NMR (121 MHz, CDCl _3): δ 51.2 (broad).
• Theoretical contents for C ₇₂ H ₇₂ BCl ₂ F ₂₄ N ₂ PRu: C: 52.89%, H: 4.44%, N: 1.71%
• Determined analytically: C: 52.92%, H: 4.35%, N: 1.73%.

B4: N, N-dimesityldecane-5,6-diamine

• ¹H NMR (300 MHz, CDCl₃): δ 6.74 (s, 4H), 3.12 (breit s, 2H), 2.98 (breit s, 2H), 2.22 (s, 6H), 2.05 (s, 12H), 1.74 (m, 2H), 1.49 (m, 2H), 1.30 (m, 8H), 0.89 (t, J = 6.8 Hz, 6H).
• ¹³C NMR (75 MHz, CDCl₃): δ 141.9, 130.2, 129.6, 128.8, 58.0, 31.1, 29.5, 23.1, 20.5, 18.8, 14.1.
• Theoretische Gehalte für C₂₈H₄₄N₂: C: 82.29%, H: 10.85%, N: 6.85%
• Analytisch bestimmt: C: 82.20%, H: 10.66%, N: 6.91%
• MS: m/z (%): 408 (1), 333 (3), 204 (100), 146 (85), 44 (92)

In a 150 ml Schlenk vessel, N, N-dimesitylethanediimine (2.92 g, 10 mmol) was dissolved under nitrogen as a blanket gas in 30 ml of THF and the solution was cooled to -78 ° C. Thereafter, 1.6 M butyllithium in hexane (13.8 ml, 22 mmol) was slowly added to the suspension at -78 ° C. The reaction mixture was warmed to -10 ° C within 1 hour and stirred at this temperature for a further hour. Thereafter, the solvent was removed and 15 ml of diethyl ether and 10 ml of water added in an ice bath. The aqueous layer was extracted twice with 5 ml of ether and the combined extracts were dried over powdered NaOH. After removal of the solvent left behind an orange oil. The crude product was chromatographed on a silica gel column (50 g) and eluted with petroleum ether / toluene (1: 1). Removal of the solvent gave yellow crystals of N, N-dimesityldecane-5,6-diamine (2.67 g, 65%).

• ¹ H NMR (300 MHz, CDCl ₃ ): δ 6.74 (s, 4H), 3.12 (broad s, 2H), 2.98 (broad s, 2H), 2.22 (s, 6H), 2.05 (s, 12H), 1.74 (m, 2H), 1.49 (m, 2H), 1.30 (m, 8H), 0.89 (t, J = 6.8 Hz, 6H).
• ¹³ C NMR (75 MHz, CDCl _3): δ 141.9, 130.2, 129.6, 128.8, 58.0, 31.1, 29.5, 23.1, 20.5, 18.8, 14.1.
• Theoretical contents for C ₂₈ H ₄₄ N ₂ : C: 82.29%, H: 10.85%, N: 6.85%
• Determined analytically: C: 82.20%, H: 10.66%, N: 6.91%
• MS: m / z (%): 408 (1), 333 (3), 204 (100), 146 (85), 44 (92)

B5: [4,5-dibutyl-1,3-dimesityl-4,5-dibydroimidazolium] tetrafluoroborate

• ¹H NMR (300 MHz, CDCl₃): δ 8.50 (s, 1H), 7.00 (s, 2H), 6.98 (s, 2H), 4.20 (breit s, 2H), 2.35 (s, 6H), 2.33 (s, 6H), 2.31 (s, 6H), 1.80 (m, 4H), 1.31 (m, 8H), 1.14 (m, 2H), 0.86 (t, J = 6.9 Hz, 6H).
• ¹³C NMR (75 MHz, CDCl₃): δ 158.4, 140.4, 135.7, 134.4, 130.4, 128.9, 69.4, 32.9, 27.2, 22.3, 21.1,18.4,18.1,13.7.
• MS: m/z (%): 419 (22), 361 (100), 305 (12), 280 (10), 146 (11), 135 (32), 57 (11).

In a 25 mL round bottom flask was added N, N-dimesityldecane-5,6-diamine from Example B3 (0.817 g, 2 mmol), NH ₄ BF ₄ (0.21 g, 2 mmol) and triethyl orthoformate (0.42 mL, 2.5 mmol). The reaction mixture was heated at 130 ° C for 4 hours under a constant flow of nitrogen. Evaporation of the solvent gave a brown oil, which was stirred with 2 ml of diethyl ether for 1 hour. The diethyl ether was decanted off and the washing was repeated twice with diethyl ether. There were obtained dark crystals as a crude product, which were subjected to column chromatography on silica gel (15 g). Elution with ethyl acetate and evaporation of the solvent gave the dihydroimidazolium salt as a light brown powder (0.72 g, 71%).

• ¹ H NMR (300 MHz, CDCl ₃ ): δ 8.50 (s, 1H), 7.00 (s, 2H), 6.98 (s, 2H), 4.20 (broad s, 2H), 2.35 (s, 6H), 2.33 ( s, 6H), 2.31 (s, 6H), 1.80 (m, 4H), 1.31 (m, 8H), 1.14 (m, 2H), 0.86 (t, J = 6.9 Hz, 6H).
• ¹³ C NMR (75 MHz, CDCl _3): δ 158.4, 140.4, 135.7, 134.4, 130.4, 128.9, 69.4, 32.9, 27.2, 22.3, 21.1,18.4,18.1,13.7.
• MS: m / z (%): 419 (22), 361 (100), 305 (12), 280 (10), 146 (11), 135 (32), 57 (11).

B6: Dichloro (-4,5-dibutyl-1,3-dimesityldihydroimidazolylidene) (tricydohexylphosphine) (phenylcarbene) ruthenium (4)

• ¹H NMR (300 MHz, CD₂Cl₂): δ 19.14 (d, J = 132 Hz, 1H), 8.96 (breit s, 1H), 7.36 (breit s, 1H), 7.23–6.52 (m, 6H), 5.96, 5.71 (zwei breit s, 1H), 3.79 (breit s, 2H), 2.90–0.65 (m, 51H).
• ³¹P NMR (121 MHz, CD₂Cl₂): δ 27.6 (s).
• ¹³C NMR (75 MHz, CD₂Cl₂): δ 295.0, 221.7, 220.7, 151.8, 140.5, 139.4 (breit), 138.6, 137.8, 137.4, 135.4 (breit), 132.4 (breit), 130.8, 130.5, 129.8, 128.0 (breit), 71.7, 70.6, 69.3, 34.9, 34.5 (breit), 32.0 (breit), 29.7 (breit), 28.8, 28.6, 28.5, 28.4, 26.8, 23.6, 23.4, 22.5, 21.5, 21.3, 20.6, 19.5 (breit), 14.3, 14.2.
• Theoretische Gehalte für C₅₄H₈₁Cl₂N₂PRu: C: 67.48%, H: 8.49%, N: 2.91%
• Analytisch bestimmt: C: 67.29%, H: 8.30%, N: 2.95%.

A solution of KO ^t Bu (0.133 g, 1.181 mmol) in 20 mL of THF was prepared in a glovebox and taken out of the box. The [4,5-dibutyl-1,3-dimesityl-4,5-dihydroimidazolium] tetrafluoroborate from Example B4 (0.57 g, 1,125 mmol) was dissolved in 10 ml of THF under nitrogen as inert gas and added to a 150 ml Schlenk vessel. The KO ^t Bu solution was combined at room temperature with the brown solution of [4,5-dibutyl-1,3-dimesityl-4,5-dihydroimidazolium] tetrafluoroborate. The cloudy, yellow-orange solution. was stirred for 1 hour; then a solution of (PCy _{3) 2} Cl ₂ Ru = CHPh (0.741 g; 0.9 mmol) in 40 ml of benzene with a syringe. The reaction mixture was heated to 80 ° C for 1.5 hours and then the solvent was removed. The residue was chromatographed on a silica gel column (10 g) and the crude product was eluted with a petroleum ether / diethyl ether mixture (4: 1) as a red zone. The solvent was removed. Under nitrogen, the red oil was extracted at 0 ° C for 1 hour with 2 ml of hexane and then filtered off. After washing the residue twice with hexane, dichloro (4,5-dibutyldihydroimidazolylidene) (tricydohexylphosphine) (phenylcarbene) ruthenium (4) was obtained as a pink solid (0.48 g, 55%).

• ¹ H NMR (300 MHz, CD ₂ Cl ₂ ): δ 19.14 (d, J = 132 Hz, 1H), 8.96 (broad s, 1H), 7.36 (broad s, 1H), 7.23-6.52 (m, 6H) , 5.96, 5.71 (two broad s, 1H), 3.79 (broad s, 2H), 2.90-0.65 (m, 51H).
• ³¹ P NMR (121 MHz, CD ₂ Cl ₂ ): δ 27.6 (s).
• ¹³ C NMR (75 MHz, CD ₂ Cl ₂ ): δ 295.0, 221.7, 220.7, 151.8, 140.5, 139.4 (wide), 138.6, 137.8, 137.4, 135.4 (wide), 132.4 (wide), 130.8, 130.5, 129.8 , 128.0 (broad), 71.7, 70.6, 69.3, 34.9, 34.5 (broad), 32.0 (wide), 29.7 (wide), 28.8, 28.6, 28.5, 28.4, 26.8, 23.6, 23.4, 22.5, 21.5, 21.3, 20.6 , 19.5 (wide), 14.3, 14.2.
• Theoretical contents for C ₅₄ H ₈₁ Cl ₂ N ₂ PRu: C: 67.48%, H: 8.49%, N: 2.91%
• Determined analytically: C: 67.29%, H: 8.30%, N: 2.95%.

B7: Carbido (dichloro) (4,5-dibutyl-1,3-dimesityldihydroimidazolylidene) (tricyclohexylphosphine) ruthenium (5)

• ¹H NMR (300 MHz, CDCl₃): δ 6.90 (pseudo t, J = 12 Hz, 4H), 3.91 (m, 1H), 3.79 (m, 1H), 2.53 (s, 3H), 2.51 (s, 3H), 2.50 (s, 3H), 2.48 (s, 3H), 2.31 (breit s, 3H), 2.28 (s, 3H), 2.24 (s, 3H), 1.98–1.48, 1.40–0.94 (alle m, 42H), 0.85 (t, J = 6.9 Hz, 3H), 0.83 (t, J = 6.9 Hz, 3H).
• ³¹P NMR (121 MHz, CDCl₃): δ 34.0 (s).
• ¹³C NMR (75 MHz, CDCl₃): δ 480.8, 211.5, 210.3, 139.5, 139.1, 137.5, 137.4, 137.3, 136.8, 134.8, 129.8, 129.7, 129.5, 129.2, 70.5, 69.1, 34.4, 34.0, 31.2, 30.9, 29.2, 29.0, 27.9, 27.8, 27.7, 26.3, 22.7, 22.6, 21.6, 21.1, 20.9, 20.6, 20.2, 19.0, 13.8, 13.7.
• Theoretische Gehalte für C₄₈H₇₅Cl₂N₂PRu: C: 65.29%, H: 8.56%, N: 3.17%
• Analytisch bestimmt: C: 65.21%, H: 8.48%, N: 3.13%

Dichloro (-4,5-dibutyldihydroimidazolylidene) (tricydohexylphosphine) (phenylcarbene) ruthenium from Example B5 (0.48 g, 0.5 mmol) and diethyl trans-3-methylene-1,2-cyclopropanedicarboxylate (0.10 g, 0.5 mmol) were added to a 25 mL Schlenk vessel given. Under nitrogen as inert gas, 5 ml of dry CH ₂ Cl _{2 was} added. The resulting red-brown solution was stirred for 12 hours. Thereafter, the brown solution was removed under high vacuum. The oily residue was treated with 2 ml of hexane under nitrogen for 1 hour. After filtration, it was washed twice with hexane to give carbido (dichloro) (4,5-dibutyl-1,3-dimesityldihydroimidazolylidene) (tricyclohexylphosphine) ruthenium (5) as a light brown solid (0.35 g, 79%).

• ¹ H NMR (300 MHz, CDCl ₃ ): δ 6.90 (pseudo t, J = 12 Hz, 4H), 3.91 (m, 1H), 3.79 (m, 1H), 2.53 (s, 3H), 2.51 (s, 3H), 2.50 (s, 3H), 2.48 (s, 3H), 2.31 (broad s, 3H), 2.28 (s, 3H), 2.24 (s, 3H), 1.98-1.48, 1.40-0.94 (all m, 42H), 0.85 (t, J = 6.9 Hz, 3H), 0.83 (t, J = 6.9 Hz, 3H).
• ³¹ P NMR (121 MHz, CDCl _3): δ 34.0 (s).
• ¹³ C NMR (75 MHz, CDCl _3): δ 480.8, 211.5, 210.3, 139.5, 139.1, 137.5, 137.4, 137.3, 136.8, 134.8, 129.8, 129.7, 129.5, 129.2, 70.5, 69.1, 34.4, 34.0, 31.2, 30.9, 29.2, 29.0, 27.9, 27.8, 27.7, 26.3, 22.7, 22.6, 21.6, 21.1, 20.9, 20.6, 20.2, 19.0, 13.8, 13.7.
• Theoretical contents for C ₄₈ H ₇₅ Cl ₂ N ₂ PRu: C: 65.29%, H: 8.56%, N: 3.17%
• Determined analytically: C: 65.21%, H: 8.48%, N: 3.13%

B8 [Dichloro (4,5-dibutyl-1,3-dimesityldihydroimidazolylidene) (tricyclohexyl phosphonio carbene)] tetrafluoroborate (6)

All glassware were in an oven at 160 ° C dried.

• ¹H NMR (300 MHz, CD₂Cl₂): δ 19.83, 19.11, 18.44 (alle s, 1H), 7.66–6.90 (m, 4H), 4.84 (m, 1H), 3.72 (m, 1H), 2.80–2.18, 2.00–0.62 (beide m, 51H).
• ³¹P NMR (121 MHz, CDCl₃): δ 34.0 (s).
• ¹³C NMR (75 MHz, CDCl₃): δ 194.8, 143.4 (breit), 139.0 (breit), 137.7, 136.8, 135.9, 135.2, 134.9, 134.0, 130.9, 129.8, 128.7, 121.7, 68.1, 66.0 (breit), 32.9, 30.9, 30.3, 28.6, 27.1, 27.0, 26.9, 26.7, 25.8, 23.1, 22.9, 21.6, 20.6, 20.2, 14.2, 14.1, –0.1, –0.8
• Theoretische Gehalte für C₄₈H₇₆BCl₂F₄N₂PRu: C: 59.38%, H: 7.89%, N: 2.89%
• Analytisch bestimmt: C: 59.01%, H: 7.68%, N: 2.75%

Carbido (dichloro) (4,5-dibutyl-1,3-dimesityldihydroimidazolylidene) (tricyclohexylphosphine) ruthenium (5) from Example B6 (0.31 g, 0.35 mmol) was initially charged in a 25 ml Schlenk vessel and 10 ml of dry CH ₂ Cl ₂ in Vacuum condensed and warmed up under nitrogen, the mixture to room temperature. [H (Et ₂ O) ₂ ] BF ₄ (0.048 mL, 0.35 mmol) was added via syringe, whereupon the reaction mixture turned green-black. After stirring for 2 hours, the solvent was vacuum stripped in oil pumps. The oily residue was treated with 2 ml of hexane under nitrogen for 1 hour and then filtered off. The washing procedure was repeated once to afford dichloro (4,5-dibutyl-1,3-dimesityldihydroimidazolylidene) (tricyclohexyl phosphoniocarben)] tetrafluoroborate (6) as a dark green microcrystalline solid (0.32 g, 94%).

• ¹ H NMR (300 MHz, CD ₂ Cl ₂ ): δ 19.83, 19.11, 18.44 (all s, 1H), 7.66-6.90 (m, 4H), 4.84 (m, 1H), 3.72 (m, 1H), 2.80 -2.18, 2.00-0.62 (both m, 51H).
• ³¹ P NMR (121 MHz, CDCl _3): δ 34.0 (s).
• ¹³ C NMR (75 MHz, CDCl ₃ ): δ 194.8, 143.4 (wide), 139.0 (wide), 137.7, 136.8, 135.9, 135.2, 134.9, 134.0, 130.9, 129.8, 128.7, 121.7, 68.1, 66.0 (wide) , 32.9, 30.9, 30.3, 28.6, 27.1, 27.0, 26.9, 26.7, 25.8, 23.1, 22.9, 21.6, 20.6, 20.2, 14.2, 14.1, -0.1, -0.8
• Theoretical contents for C ₄₈ H ₇₆ BCl ₂ F ₄ N ₂ PRu: C: 59.38%, H: 7.89%, N: 2.89%
• Determined analytically: C: 59.01%, H: 7.68%, N: 2.75%

II Stability of the catalyst according to the invention from example B3 [dichloro (1,3-dimesityldihydroimidazolylidene) (tricyclohexylphosphoniocarben)] tetrakis (3,5-trifluoromethylphenyl) borate (ruthenium compound 3 from Example B3) in comparison with 13-bis (2,4 , 6-trimethylphenyl) -2-imidazolidenylidene) (tricyclohexylphosphine) ruthenium (phenylmethylene) dichloride ("Grubbs (II) catalyst") in solution).

The stability of the dissolved catalysts was determined by NMR in deuterochloroform (CDCl ₃ ) and in deuterobenzene (C ₆ D ₆ ).

Here, [dichloro (1,3-dimesityldihydroimidazolylidene) (tricyclohexylphosphoniocarben)] [tetrakis (3,5-trifluoromethylphenyl) borate] (inventive ruthenium compound 3 of Example B3) with 1,3-bis (2,4,6-trimethylphenyl ) -2-imidazolidenyliden) (tricyclohexylphosphine) ruthenium (phenylmethylene) dichlori d_ (Grubbs (II) catalyst) comparatively investigated. The Grubbs (II) catalyst was purchased from Materia Inc. (Pasadena California, USA). In each case 0.01 molar solutions (4.2 mg Grubbs (II) catalyst per 0.5 ml of solvent and 8.2 mg of catalyst from B3 per 0.5 ml of solvent) were used. The solutions were prepared without protective gas in air. The solutions were filled with NMR tubes which were stored at 24 ° C. At intervals of 30 minutes, the NMR tubes were opened in the air and shaken vigorously. The concentration determinations were carried out every hour.

The following temporal dependencies of the relative concentrations were determined in deuterochloroform:

During the Service life of the catalyst solutions changed the color of the Grubbs (II) catalyst of purple to orange-brown. As a decomposition product of the Grubbs (II) catalyst Benzaldehyde was formed. The solution the catalyst according to the invention B3 was initially orange. While the service life of the solution the color became barely recognizable darker. Decomposition products of inventive catalyst B3 were not detectable by NMR.

The following temporal dependencies of the relative concentrations were determined in deuterobenzene:

During the Service life of the catalyst solutions changed the color of the Grubbs (II) catalyst of purple to dark brown. As a decomposition product of the Grubbs (II) catalyst Benzaldehyde was formed. The solution the catalyst according to the invention B3 was initially light green. While the service life of the solution the catalyst according to the invention from B3 was no color change to observe. Decomposition products of the catalyst according to the invention from B3 were not detectable by NMR.

The Investigations show that the catalyst according to the invention consists of B3 [dichloro (1,3-dimesityldihydroimidazolylidene) (tricyclohexyl-phosphoniocarben)] [tetrakis (3,5-trifluoromethylphenyl) borate] in oxygen-containing solvents has a significantly better stability than corresponding ones solutions of the Grubbs (II) catalyst.

III. Use of the Ru catalysts according to the invention from Examples B2, B3 and B8 for the metathesis degradation of nitrile rubbers

The degradation reactions described below were carried out 3435 from Lanxess Germany GmbH using the nitrile Buna ^® NT. This nitrile rubber had the following characteristics:

acrylonitrile content: 35 Wt .-% Mooney (ML 1 + 4 @ 100 ° C): 34 Mooney Residual moisture: 1.8 Wt .-% M _w : 240000 g / mol M _n: 100000 g / mol PDI (M _w / M _n ): 2.4

following This nitrile rubber is abbreviated to NBR.

For the metathesis removal were each used 293.3 g of chlorobenzene (hereinafter referred to as "MCB" / Aldrich), the distilled before use and at room temperature by passing saturated with oxygen has been. Herein were 40 g of NBR during a period of 10 h at room temperature. To the NBR-containing solution were each 0.8 g (2 phr) of 1-hexene given and for homogenization 30th stirred for a few minutes.

For the implementation of Metathesis reactions were as indicated in the tables below Amounts of the above-described invention Ru catalysts from the Examples B2, B3 and B7 used. The Ru catalysts were therefor each in 20 g of MCB at room temperature without the use of inert gas solved. Before using MCB for the preparation of the catalyst solutions Air was passed through each at room temperature to the solvent to saturate with oxygen. In the experimental series 1) and 2), the addition of the catalyst solutions was carried out to the NBR solutions in MCB immediately after preparation of the catalyst solutions. In the experimental series 3), the catalyst solution became 4 days before use at 40 ° C stored.

The Reaction temperatures in the implementation of metathesis reactions are noted in the following tables. After in the tables given reaction times were from the reaction solutions respectively about 5 ml of solution removed and stop immediately with about 0.2 ml of ethyl vinyl ether offset and then diluted with 5 ml of DMAc (N, N-dimethylacetamide) from Aldrich. From these solutions were 2 ml each into a GPC vial and diluted to 3 ml with DMAc. Before performing the GPC analysis became the solutions each by means of a 0.2 micron syringe filter made of Teflon (Chromafil PTFE 0.2 μm; Machery-Nagel). This was followed by the GPC analysis with one device the company Fa. Waters (mod. 510). For the analysis was a combination of 4 columns Polymer Laboratories uses: 1) PLgel 5μm Mixed-C, 300 × 7.5mm, 2) PLgel 5μm Mixed-C, 300 × 7.5mm, 3) PLgel 3μm Mixed-E, 300 × 7.5mm, and 4) PLgel 3μm Mixed-E, 300 × 7.5mm.

The Calibration of the GPC columns was carried out with linear poly (methyl methacrylate) from Polymer Standards Services. The detector used was a RI detector from Waters (Waters 410). The analysis was carried out with a flow rate of 0.5 mL / min carried out, using as the eluent DMAc. The evaluation of the GPC curves was done with software from Millenium.

• M_w [kg/mol]: Gewichtsmittel der Molmasse
• M_n [kg/mol]: Zahlenmittel der Molmasse
• PDI: Breite der Molmassenverteilung (M_w/M_n)

By GPC analysis, the following characteristic parameters were determined for both the NBR original rubber (before degradation) and the degraded products:

• M _w [kg / mol]: weight average molecular weight
• M _n [kg / mol]: number average molecular weight
• PDI: width of the molecular weight distribution (M _w / M _n )

With the Ru compounds B2, B3 and B8 described above became three Experimental series carried out, in which it is shown that these Ru compounds for catalysis suitable for NBR degradation are:

Experimental series 1) NBR metathesis using [dichloro (1,3-dimesityldihydroimidazolylidene) (tricyclohexylphosphoniocarben)] tetrafluoroborate (Ru catalyst (2) from B2)

Tables 1a and 1b:

In of the test series 1) it is shown that the Ru catalyst according to the invention (2) from Example B2 in an oxygen-saturated MCB solution Metathesis degradation of NBR catalyzed at a reaction temperature of 55 ° C. The degraded NBR obtained in the experimental series 1) is gel-free.

Experimental series 2) NBR metathesis using [dichloro (1,3-dimesityldihydroimidazolylidene) (tricyclohexylphosphoniocarben)] [tetrakis (3,5-trifluoromethylphenyl) borate] (inventive Ru catalyst (3) from B3)

Tables 2a and 2b:

In the series of experiments 2) it is shown that the Ru catalyst according to the invention (3) from B3 in an oxygen-saturated MCB solution 55 ° C the Metathesis of NBR catalyzes. The one obtained in the experimental series 2) degraded NBR is gel-free.

Test series 3)

Using NBR metathesis of [dichloro (4,5-dibutyl-1,3-dimesityldihydroimidazolylidene) (tricyclohexylphosphoniocarben)] tetrafluoroborate (inventive Ru catalyst (6) B8)

at This series of experiments was the oxygenated MCB solution of the Ru catalyst according to the invention (6) from B8 stored for 4 days before use at 40 ° C.

In of the experimental series 3) it is shown that the Ru catalyst according to the invention (6) from B8 in an oxygen-saturated MCB solution as well after storage of the catalyst solution at 40 ° C over a Period of 4 days catalyzes the metathesis of NBR at 23 ° C. The degraded NBR obtained in the experimental series 3) is gel-free.

Claims (12)

Catalyst of general formula (I)

wherein M is ruthenium or osmium, X ¹ and X ^{2 may be the} same or different and are anionic ligands, R ¹ , R ² and R ^{3 are the} same or different and represent organic radicals, Im represents an optionally substituted Imidazolidinrest and A represents an anion , A catalyst according to claim 1, wherein X ¹ and X ² in the general formula (1) are the same or different and are, for example, hydrogen, halogen, pseudohalogen, C ₁ -C ₂₀ alkyl, aryl, C ₁ -C ₂₀ alkoxy, aryloxy, C C ₃ -C ₂₀ -alkyl diketonate, aryldiketonate, C ₁ -C ₂₀ -carboxylate, arylsulfonate, C ₁ -C ₂₀ -alkyl sulfonate, C ₁ -C ₂₀ -alkylthiol, arylthiol, C ₁ -C ₂₀ -alkylsulfonyl or C ₁ -C ₂₀ Alkylsulfinyl radicals represent. Catalyst according to claim 1 or 2, wherein the radicals R ¹ , R ² and R ³ in the radical P (R ¹ R ² R ³ ) of the general formula (1) are identical or different and straight-chain or branched C ₁ -C ₃₀ -alkyl , C ₅ -C ₃₀ -cycloalkyl or aryl, wherein the C ₁ -C ₃₀ -alkyl radicals may optionally be interrupted by one or more double or triple bonds or else one or more heteroatoms, preferably oxygen or nitrogen. Catalyst according to one or more of claims 1 to 3, wherein the radical P (R ¹ R ² R ³ ) in the general formula (I) triphenylphosphine, tricyclohexylphosphine, tricyclopentylphosphine, triisopropylphosphine, tri (o-tolyl) phosphine, tri (o-) xylyl) phosphine or trimesitylphosphine. Catalyst according to one or more of claims 1 to 4, wherein the imidazolidine residue (Im) in the has the general formula (I) has a structure of the general formulas (IIa) or (IIb),

in which R ⁴ , R ⁵ , R ⁶ , R ^{7 can be} identical or different and are hydrogen, straight-chain or branched, cyclic or acyclic C ₁ -C ₂₀ -alkyl, C ₂ -C ₂₀ -alkenyl, C ₂ -C ₂₀ -alkynyl, Aryl, C ₁ -C ₂₀ -carboxylate, C ₁ -C ₂₀ -alkoxy, C ₂ -C ₂₀ -alkenyloxy, C ₂ -C ₂₀ -alkynyloxy, aryloxy, C ₂ -C ₂₀ -alkoxycarbonyl, C ₁ -C ₂₀ - Akylthio, arylthio, C ₁ -C ₂₀ alkylsulfonyl, C ₁ -C ₂₀ alkyl sulfonate, C ₆ -C ₂₀ arylsulfonate and C ₁ -C ₂₀ alkylsulfinyl. Catalyst according to one or more of claims 1 to 5, wherein the Imidazolidinrest (Im) in the general formula (I) has a structure of the general formulas (IIIa-f)

Catalyst according to one or more of the claims 1 to 6, wherein A in the general formula (1) is nitrate, Fluorosulfonate, trifluoromethanesulfonate (triflate), a halide, a pseudohalide, a complex anion or a noncoordinating one Anion acts. Catalysts according to one or more of claims 1 to 7 of the following structures (IVa-c):

where R ¹ , R ² , R ^{3 represent} straight-chain or branched C ₁ -C ₃₀ -alkyl, C ₅ -C ₁₀ -cycloalkyl or aryl, where the C ₁ -C ₃₀ -alkyl radicals are optionally substituted by one or more double or triple bonds or also one or more heteroatoms, preferably oxygen or nitrogen, may be interrupted and A has the meanings given for the general formula (I). Catalysts according to one or more of claims 1 to 8, wherein the radical P (R ¹ R ² R ³ ) triisopropylphosphine, triphenylphosphine, Tricyclohexylphoshin, tricyclopentylphosphine, tri (o-tolyl) phosphine, tri (o-xylyl) phosphine or Trimesitylphosphin means and A is bromide, tetrafluoroborate, tetrakis (3,5-trifluoromethylphenyl) borate, tetrakis [pentafluorophenyl] borate or bis ((tris-pentafluorophenyl) boron) cyanide. Process for the metathesis degradation of nitrile rubbers, wherein a nitrile rubber of a metathesis reaction in the presence a catalyst according to a or more of the claims Subject to 1-9. Process according to claim 10, wherein the nitrile rubbers used for the metathesis have a Mooney viscosity (ML 1 + 4 @ 100 ° C) in the range from 30 to 70, preferably from 30 to 50 and a polydispersity PDI = M _w / M _n , where M _{n is} the number average and M _{w is} the weight average molecular weight, in the range of 2.0-6.0 and preferably in the range of 2.0-4.0. Process for the preparation of hydrogenated nitrile rubbers, characterized in that subsequent to the method according to claim 10 or 11, hydrogenation of the nitrate rubber degraded by the metathesis performs.