EP2558526A2 - Cross-linking agents containing isocyanate groups for nitrile rubbers - Google Patents

Abstract

By using specific cross-linking agents which contain at least two isocyanate groups, optionally hydrated nitrile rubber terpolymers containing hydroxyl groups can be cross-linked successfully. Preferred cross-linking agents have allophanate, biuret, uretdione, uretoneimine, bridged carbamate, carbodiimide, isocyanurate, iminooxadiazindione or oxadiazintrione structural elements.

Description

 Isocyanate group-containing crosslinkers for nitrile chutneys

The invention relates to the use of special compounds containing at least two isocyanate groups as crosslinkers for hydroxyl-containing (H) NBR rubbers, corresponding vulcanizable compositions, processes for their preparation, processes for the preparation of vulcanizates thereof and the vulcanizates thus obtained, and hydroxyl-containing HNBR rubbers.

Nitrile rubbers, also abbreviated to "NBR", are rubbers which are copolymers or terpolymers of at least one α, β-unsaturated nitrile, at least one conjugated diene and optionally one or more further copolymerizable monomers Nitrile rubbers ("HNBR") are understood as corresponding copolymers or terpolymers in which the C =C double bonds of the copolymerized diene units are completely or partially hydrogenated. The term (H) NBR includes both NBR and HNBR.

Both NBR and HNBR have been firmly established in the field of specialty elastomers for many years. They have an excellent property profile in the form of excellent oil resistance, good heat resistance, excellent resistance to ozone and chemicals, the latter being even more pronounced in the case of HNBR than NBR. NBR and HNBR also have very good mechanical and performance properties. For this reason, they are widely used in a variety of applications and are used, for example, for the production of seals, hoses, belts and damping elements in the automotive sector, also for stators, borehole seals and valve seals in the field of oil production and also for many parts of the electrical industry, the machine industry. and shipbuilding. Commercially available are a variety of different types, which are characterized by different monomers, molecular weights, polydispersities and mechanical and physical properties depending on the application. In addition to the standard types, special types are increasingly in demand, which are increasingly in demand due to the content of special termonomers or special functionalizations.

In the practical use of (H) NBR rubbers, the vulcanization of the rubbers, ie in particular the crosslinker system and the vulcanization conditions, is of increasing importance. In addition to the classic rubber crosslinking systems based on peroxides or sulfur, which have existed for many decades, various new concepts for alternative crosslinking have been developed in recent years. Such crosslinking concepts also include polymers that are not accessible to all crosslinking forms and agents due to functional groups and therefore present a particular challenge. On a large scale, nitrile rubbers are almost exclusively produced by so-called emulsion polymerization. Dodecylmercaptans, in particular tertiary dodecylmercaptans ("TDDM"), are usually used to control the molecular weight and thus also the viscosity of the nitrile rubber formed, after the polymerization the resulting NBR latex is coagulated in a first step and the NBR solid is isolated therefrom. If a further hydrogenation of the nitrile rubber to HNBR is desired, this hydrogenation is likewise carried out by known methods of the prior art, for example using homogeneous or else heterogeneous hydrogenation catalysts.The catalysts are usually based on rhodium, ruthenium or titanium, but it is also possible to use platinum, iridium , Palladium, rhenium, ruthenium, osmium, cobalt or copper are used either as metal or preferably in the form of metal compounds.

On an industrial scale, such hydrogenation reactions of NBR to HNBR are usually in homogeneous phase, i. carried out in an organic solvent. Suitable catalysts and solvents for this purpose are known, for example, from DE-A 25 39 132 and EP-A 0 471 250. In particular, the so-called Wilkinson catalyst has been proven for selective hydrogenation of nitrile rubbers in monochlorobenzene as an organic solvent. In order to carry out this hydrogenation in an organic medium, the nitrile rubber obtained after the polymerization in aqueous emulsion must therefore first be isolated. This is procedurally and technically complex and thus not economically attractive.

In addition, during the hydrogenation of nitrile rubbers, a very considerable increase in viscosity (usually by a factor of 2 or more) can be observed (the so-called Mooney jump). For this reason, nitrile rubbers may have to undergo a reduction in molecular weight (eg by metathesis) before the hydrogenation in a further step in order ultimately to be able to obtain a hydrogenated nitrile rubber with not too high molecular weight or not too high viscosity. In the hitherto known and industrially feasible synthetic routes, the possibilities for influencing the polydispersity are to some extent limited. The crosslinking of hydroxyl-containing nitrile rubbers with diisocyanates is known per se. US 3,551,472 relates to liquid hydroxyl-terminated NBR rubbers. First, carboxyl-terminated NBR rubbers are prepared, which are subsequently reacted with excess 1,4-butanediol. The resulting rubber can be further reacted with monomeric toluene diisocyanate and should have advantageous adhesive properties. JP 55-151017, filed 15.05.1979 (Application No. 54-56800) relates to a nitrile rubber having hydroxyl groups. It is described that this rubber can be crosslinked with monomeric diisocyanates. Dibutyltin dilaurate is used, for example, in the crosslinking with 2,4-toluene diisocyanate as the catalyst.

The use of tin-containing catalysts leads to heavy metal loading of the nitrile rubber and makes the handling of the rubber composition considerably more difficult.

Due to their low vapor pressure and low functionality, the monomeric diisocyanates used are difficult to process or incorporate into the nitrile rubber compositions.

In WO-A-2003/076537 liquid coating compositions are described which can be crosslinked at room temperature and based on a film-forming polymer having a glass transition temperature Tg <0 ° C and less than 10% ethylenic unsaturation. Generally disclosed are coating compositions containing (A) a carboxylated, hydrogenated acrylonitrile-butadiene copolymer (X-HNBR), (B) a crosslinker having at least one isocyanate graft and another crosslink site forming group, and (C) a solvent. Coating compositions which have a solids content of 3-30 wt.% Of a) the carboxylated, hydrogenated copolymer having recurring units of a conjugated diene, an unsaturated nitrile and a carboxyl monomer and b) a crosslinker having at least one isocyanate group and another group, forms the networking sites. As the solvent (C), there are mentioned water, any organic solvents and any other substances which can dissolve carboxylated hydrogenated acrylonitrile-butadiene copolymers. The solvent (C) is thus used in amounts of from 70 to 97% by weight, based on the total coating composition. The liquid compositions are applied to the surface to be coated, dried and vulcanized. Networking times of 16 hours are described. Crosslinkers (B) are generally polyisocyanates, chain-extended polyisocyanates, polymeric isocyanate-polyol adducts, polycarbodiimides, multifunctional oxazolines, multifunctional oxazines, multifunctional imidazolines, phenolic novolacs, phenolic resoles, amino resins and amino (alkoxy) silanes. Explicitly described in Example 3 are aqueous HXNBR latices in combination with a crosslinker in the form of an aromatic prepolymer based on diphenylmethane diisocyanate or an aliphatic prepolymer based on 1,6-hexamethylene diisocyanate. Similar two component coating compositions are also described in WO-A-2004/033573. However, these are still added in addition thermally conductive metal particles. EP-A-0 001 092 describes liquid hydroxyl group-containing polymers having aliphatic polymer backbones which have sulfide bonds close to the end groups of the polymer molecules and are obtained by polymerizing (1) at least one vinylidene monomer with a mixture of at least one hydroxyl group. containing disulfide and at least one hydroxyl-containing trisulfide. Rubbers having repeating units of at least one conjugated diene and at least one unsaturated nitrile and at least one copolymerizable hydroxyl group-containing monomer are not described. The use of the mixture of di- and trisulfide allows the control of the molecular weight and allows the preparation of liquid polymers.

The object of the present invention was thus to provide crosslinkers for hydroxyl-group-containing (H) NBR rubbers which avoid the disadvantages of the existing crosslinkers. They should be able to be used in particular without the use of tin-containing catalysts for crosslinking and preferably have a high vapor pressure and high functionality.

The chemicals used as crosslinkers should also have good handleability and low toxicity. The optionally crosslinked, optionally hydrogenated nitrile rubbers should preferably give good to very good values in the compression set test and in the tensile elongation test, have good to very good vulcanization behavior (measured usually in an MDR rotary vulcanometer) and thus offer an alternative to the conventional systems.

The object is achieved according to the invention by the use of compounds of the general formula (I), (II), (III) or (IV) as crosslinkers for hydroxyl-containing (H) NBR rubbers, wherein

R ¹ 0- [M] _p -R ³ , NH- [M] _P -R ³

 2 H

or R ¹ and R ² together represent a single bond or one of the following groups - yield,

 wherein

 n is an integer from 1 to 4 and

 m = 4-n

wherein in the general formulas (I), (II), (III) and (IV)

R ³ , R ⁴ , R ^{3 are} identical or different and denote H or a radical which contains one or more of the following groups,

 a saturated, mono- or polyunsaturated carboxylic or heterocyclyl radical, straight-chain or branched alkyl, aryl, heteroaryl, arylalkyl, heteroarylalkyl, alkoxy, aryloxy, heteroaryloxy, amino, amido, hydroxyimino, carbamoyl, alkoxycarbonyl, F, Cl, Br, I, Hydroxy, phosphonato, phosphinato, alkylthio, arylthio, sulfanyl, thiocarboxy, sulfinyl, sulfono, sulfino, sulfeno, sulfonic acids, sulfamoyl, silyl, silyloxy, nitrile, sulfanyl, hydroperoxycarbonyl, hydroperoxy, thiocarboxy, dithiocarboxy, hydroxyimino, nitro, nitrosyl, carbonyl, Carboxy, oxycarbonyl, oxysulfonyl, oxo, thioxo, borate, selenate, epoxy, cyanate, thiocyanate, isocyanate, thioisocyanate or isocyanad,

M for repeating units of one or more, mono- or polyunsaturated

Monomers comprising conjugated or non-conjugated dienes, alkynes and vinyl compounds, or a divalent structural element which is derived Polymers comprising polyethers, in particular polyalkylene glycol ethers and polyalkylene oxides, polysiloxanes, polyols, polycarbonates, polyurethanes, polyisocyanates, polysaccharides, polyesters and polyamides, and

p, q, r, are the same or different and are in the range of 0 to 10,000,

and wherein the compounds of the general formula (I), (II), (III) and (IV) each contain at least two isocyanate groups.

The formulation that in the compounds of general formula (I), (II), (III) and (IV) in each case "at least two isocyanate groups" are included, means in the context of this application that these are either at least two free isocyanate groups (-NCO) or are protected isocyanate groups from which the -NCO groups are released in situ under the crosslinking conditions.

In a preferred embodiment, the at least two isocyanate groups in the compounds of the general formula (I), (II), (III) and (IV) are present in at least two of the radicals R ³ , R ⁴ and R ^5, respectively.

With particular preference the compounds of the general formula (I), (II), (III) or (IV) are dimers or trimers of monomeric diisocyanates.

The crosslinkers according to the invention have the advantage that they can be used in the absence of tin-containing compounds and lead to good crosslinking of the hydroxyl group-containing (H) NBR rubbers. The invention further provides a vulcanizable composition containing at least one hydroxyl group-containing (H) NBR rubber and at least one crosslinker, as defined above or below.

The invention also provides a process for the preparation of these vulcanizable compositions by mixing at least one hydroxyl-containing (H) NBR autoshock and at least one crosslinker as defined above or below.

The invention furthermore relates to a process for the preparation of vulcanizates, in which the above vulcanizable compositions are crosslinked with heating, and to the vulcanizates, preferably moldings obtainable by this process. It has been found that by the use according to the invention of the compounds of the general formula (I), (II), (III) or (IV), in particular the dimers or trimers of monomeric diisocyanates, a thermally stable network with the hydroxyl group-containing optional hydrogenated nitrile rubbers can be constructed and no tin compounds or heavy metal compounds are needed as a further crosslinking catalyst for good crosslinking. The compounds of the general formula (I), (II), (III) or (IV) used can also be handled easily. The vulcanizates produced show very good values in the compression set test at room temperature and 100 ° C. and furthermore a high tensile stress with good breaking elongations. Especially when HEMA (hydroxyethyl methacrylate) is used as the hydroxyl-containing termonomer in the optionally hydrogenated nitrile rubber, very good results can be achieved.

In the use according to the invention, it is proven that solvents are not present at all or only in small amounts. For example, a use according to the invention in which either no or not more than 15% by weight of solvent, based on the hydroxyl group-containing (H) NBR rubber is present, has proven useful. Not more than 10% by weight, particularly preferably not more than 5% by weight, very particularly preferably not more than 2% by weight and especially preferably not more than 1% by weight of solvent, based on the hydroxyl group-containing (H ) NBR- autschuk present. By "solvent" are meant in particular water, any organic solvents and any other substances which dissolve hydroxyl-containing (H) NBR rubber or any mixtures of the abovementioned.

This means that the hydroxyl group-containing (H) NBR rubber is used in the inventive use as such, that is, in bulk. In particular, it is not pretreated in a separate solution step.

Despite the absence of solvents or the presence of only small amounts, the hydroxyl group-halo (H) NBR rubbers used can be crosslinked with the compounds of the general formula (I), (II), (III) or (IV) in an excellent and rapid manner. This is surprising since it could be assumed that problems could arise here, in particular due to insufficient mobility of the crosslinkers in the polymer matrix, in the case of short crosslinking times. The absence of solvents or the presence of only small amounts also reduces the partial vapor pressure and the vapor pressure of the mixture, thus resulting in lower emissions - especially in organic solvents. The compounds of the general formula (I), (II), (III) or (IV) to be used according to the invention preferably have at least one allophanate, biuret, uretdione, isocyanurai, iminooxadiazinedione, bridged carbamate, oxadiazinetrione, Uretonimine or carbodiimide structure.

As compounds of the general formula (I), the following compounds are general

(The compound of the structure (1-1) represents an allophanate and is represented by the general formula (I) when R ¹ = O- [M] _p -R ³ , wherein R ³ , R ⁴ and R ⁵ in total

Groups must contain).

(The compound of the structure (1-2) represents a biuret and is represented by the general formula (I) when R ¹ = NH- [M] _P -R ³ , wherein R ³ , R ⁴ and R ⁵ in total must contain at least two NCO groups.)

(The compound of structure (1-3) represents a uretdione and is represented by the general formula (I) when R ¹ and R ² together form a single bond, wherein R ⁴ and R ⁵ in total contain at least two NCO groups have to.)

(The compound of the structure (1-4) represents an isocyanurate and is represented by the general formula (I) when R ¹ and R ² together form a group

in which R ³ , R ⁴ and R ⁵ must contain in total at least two NCO groups.)

(The compound of the structure (1-5) represents an iminooxadiazine dione and is represented by the general formula (I) when R ¹ and R ² together form a group

N + M + R ³

II ^LJ p

 - o-c-

wherein R ³ , R ⁴ and R ⁵ in total contain at least two NCO groups

(The compound of the structure (1-6) represents an oxadiazinetrione and is represented by the general formula (I) when R ¹ and R ² together represent a group (-O-C (= O) -) wherein R ⁴ and R ³ in total must contain at least two NCO groups.) wherein in the formulas (II) to (1-6)

R ³ , R ⁴ and R ^{5 are the} same or different and denote H or a radical containing one or more of the following groups,

 a linear or branched, saturated, mono- or polyunsaturated alkyl radical, a saturated, mono- or polyunsaturated carbo- or heterocyclyl radical, aryl,

Heteroaryl, arylalkyl, heteroarylalkyl, alkoxy, aryloxy, heteroaryloxy, amino, amido, hydroxyimino, carbamoyl, alkoxycarbonyl, F, Cl, Br, I, hydroxy, phosphonato, phosphinato, alkylthio, arylthio, sulfanyl, thtocarboxy, sulfinyl, sulfono, sulftno, Sulfeno, sulfonic acids, sulfamoyl, silyl, silyloxy, nitrile, sulfanyl, hydroperoxycarbonyl, hydroperoxy, thiocarboxy, dithiocarboxy, hydroxyimino, nitro, nitrosyl, carbonyl,

Carboxy, oxycarbonyl, oxysulfonyl, oxo, thioxo, borate, selenate, epoxy, cyanate, thiocyanate, isocyanate, thioisocyanate or isocyanide,

 M for repeating units of one or more mono- or polyunsaturated monomers, comprising conjugated or non-conjugated dienes, alkynes and vinyl compounds, or for a divalent structural element which is derived

Polymers comprising polyethers, in particular polyalkylene glycol ethers and polyalkylene oxides, polysiloxanes, polyols, polycarbonates, polyurethanes, polyisocyanates, polysaccharides, polyesters and polyamides and

p, q, r are the same or different and are each in the range of 0 to 10,000.

In a further preferred variant, in the compounds of the structures (I-1) to (1-6), the indices p, q and r are each equal to zero.

It is also possible that the abovementioned structures (I-1) to (1-6) also occur several times in the molecule and are then connected via bridging (di-, tri- or polyisocyanate) -structure elements.

The compounds of general formula (II) are bridged carbamates. Just for clarification was performed in that the radicals R ³ is not only different R may be of the radicals ⁴ but also the radicals R ³ may be different from each other, as well as the radicals R ⁴ to be different to each other when a plurality of R ^J or R ⁴ are present in the molecule.

In the compounds of general formula (III) is a uretonimine, in the compounds of general formula (IV) is a carbodiimide. Insofar as the term "substituted" is used in this application, this means that a hydrogen atom on a given radical or atom is replaced by one of the specified groups, with the proviso that the valency of the specified atom is not exceeded and always only on the condition that this substitution leads to a stable compound.

The meanings given for the radicals R ³ , R ⁴ , R ⁵ in the general formulas (I) to (IV) and (I-1) to (I- ⁶ ) may each be mono- or polysubstituted. The following radicals are preferably monosubstituted or polysubstituted: alkyl, carbocyclyl, heterocyclyl, aryl, heteroaryl, arylalkyl, heteroarylalkyl, alkoxy, aryloxy, alkylthio, arylthio, amino, amido, carbamoyl, phosphonato, phosphinato, sulfanyl, thiocarboxy , Sulfmyl, sulfono, sulfino, sulfeno, sulfamoyl, silyl, silyloxy, carbonyl, carboxy, oxycarbonyl, oxysulfonyl, oxo, thioxo, borate, selenate and epoxy.

As substituents come - as far as chemically stable compounds arise - all meanings in question, R ³ , R ⁴ , R ³ can assume. Particularly suitable substituents are halogen, preferably fluorine, chlorine, bromine or iodine, nitrile (CN) and carboxy.

The meanings given for R ¹ , R ² , R ³ , R ⁴ and ³ in the general formulas (I) to (TV) and (I-1) to (I- ⁶ ) also explicitly include salts of the abovementioned compounds of R ¹ - R ⁵ , as far as they are chemically possible and stable. These may be, for example, ammonium salts, alkali salts, alkaline earth salts, aluminum salts or protonated forms of the compounds of the general formulas (I) to (IV) and (1-1) to (1-6) ,

The meanings given for R ¹ , R ² , R ³ , R ⁴ and R ³ in the general formulas (I) to (IV) and (I-1) to (I- ⁶ ) also include compounds of R ^! , R ² , R ³ , R ⁴ and R ⁵ with organometallic radicals, for example, those which give the respective compound a Grignard function. R ¹ , R ² , R ³ , R ⁴ and R ⁵ may furthermore represent or have a carbanion, with lithium, zinc, tin, aluminum, lead and boron in a correspondingly equivalent form as counterion.

It is also possible borrowed that R ¹ , R ² , R ³ , R ⁴ and R ⁵ is coupled via a linker to a solid phase or carrier substance. The linker may be Wang, Sasrin, Rink acid, 2-chlorotrityl, Mannich, Safety Catch, Traceless or photolabile linker known to those skilled in the art. Examples of solid phases or carriers are silica, ion exchange resins, clays, montmorillonites, cross-linked polystyrene, polyethylene glycol grafted onto polystyrene, polyacrylamides ("pepsyn"), polyethylene glycol-acrylamide copolymers (PEGA), cellulose, cotton and granular porous glass (CPG , controlled pore glass) in question. It is also possible that the compounds of the general formulas (I) to (IV) or (1-1) to (I-6) act as ligands for organometallic complex compounds, for example those based on the central metals rhodium, ruthenium, titanium Platinum, iridium, palladium, rhenium, ruthenium, osmium, cobalt iron or copper.

The meanings given above for the radical "M" may be monosubstituted or polysubstituted, meaning that M may be repeating units of one or more mono- or polyunsaturated monomers, preferably of optionally mono- or polysubstituted conjugated or non-conjugated monomers Dienes, optionally mono- or polysubstituted alkynes or optionally mono- or polysubstituted vinyl compounds, for example fluorinated mono- or polyunsaturated vinyl compounds, or else a divalent structural element which is derived from substituted or unsubstituted polymers comprising polyethers, in particular polyalkylene glycol ethers and polyalkylene oxides, Polysiloxanes, polyols, polycarbonates, polyurethanes, polyisocyanates, polysaccharides, polyesters and polyamides.

The radicals "M" can thus be monomeric or polymeric radicals.

The radicals R ¹ , R ² , R ³ , R ⁴ , R ⁵ contain in total two or more isocyanate groups for crosslinking. These may alternatively also be protected with a protective group as known to the person skilled in the art, which is removed during or before vulcanization (in the latter case already after mixing with the hydroxy group-containing (H) BR) by a process known to the person skilled in the art. R ¹ - R ⁵ may, but need not be, different groups.

The preparation of corresponding compounds of the general formulas (I) to (IV) is known per se to a person skilled in the art and can be carried out, for example, according to the procedure described in EP 1 422 223 A1 using phosphine-containing catalyst systems. The compounds of the general formulas (I) to (IV) can furthermore be prepared by methods which are described in EP 1 521 789 A1 (using 1,2,3- or 1,2,4-triazolates as catalysts), the article in Polymer Preprints (American Chemical Society) 2003, 44 (1), 46-47 (using polyfluorides as catalysts). EP 1 352 006 A1 (using superacids as catalyst) and EP 0 572 995 A1 (using imidazole-containing polymers). Reference should be made, inter alia, to WO 2004/005364 and WO 2004/005364 and DE 10 2007 058 487 AI for the preparation of compounds containing uretdione groups. Reference is made to DE 10 2005 058 835 Al for compounds containing carbodiimide and uretonimine structure. No. 4,115,373 A describes the trimerization of isocyanates to compounds containing isocyanurate groups in inert Solvents using Mannich bases as catalysts. An overview of isocyanate oligomerization is given in J. Prakt. Chem./Chem. Ztg. 1994, 336, 185-200.

As a crosslinker for the optionally hydrogenated nitrile rubber thus a dimeric, trimeric, oligomeric or polymeric di- or polyisocyanate is used. The term "di- or polyisocyanate" stands for the fact that the crosslinker has two or more free or optionally blocked isocyanate groups in the molecule, "dimer, trimer, oligomer or polymer" stands for the fact that the crosslinker from a corresponding number of two, three or more monomeric mono-, di- or polyisocyanates is constructed.

The preparation of blocked or protected isocyanate functionalities and their deprotection are described, inter alia, in the article "Blocked Isocyanates" by ZW Wieks Jr. Progress in Organic Coatings 1975, 3, 73-99 and "Blocked Isocyanates III: Part A: Mechanism and Chemistry described by ZW Wieks Jr., DA Wieks in Progress in Organic Coatings 1999, 36, 148-172. In general, a blocked isocyanate is understood as meaning an isocyanate which has been reacted with a blocking reagent and which reacts in the presence of a nucleophile to give its isocyanate adduct, it being possible for the blocking reagent to be removed from the isocyanate again by suitable reaction conditions. Preference is given to the use according to the invention of crosslinkers which (i) have as structural units units of dimeric and trimeric diisocyanates, these also being able to occur more than once in the crosslinker molecule, and having (ii) two or more free isocyanate groups in the molecule. Particular preference is given to the use of crosslinkers based on dimeric or trimeric diisocyanates which have allophanate, biuret, uretdione, uretonimine, bridged carbamate, carbodiimide, oxadiazinetrione, isocyanurate or iminooxadiazinedione structural elements and also two or more free ones Isocyanate glands in the molecule. These may also be present as oligomeric or polymeric allophanates, biurets, uretdiones, uretonimines, bridged carbamates, carbodiimides, isocyanurates, oxadiazintriones or iminooxadiazinediones, ie the individual rings are then linked to form an oligomer or polymer. A corresponding oligomer or polymer formation occurs in particular when di- or polyfunctional isocyanates are used as monomeric isocyanates. In principle, it is possible that the crosslinker is based on a single type of monomeric, oligomeric or polymeric di- or polyisocyanate. But it is also possible that the mentioned structural elements by a reaction of various monomeric, oligomeric or polymeric di- or polyisocyanates come about.

Suitable examples of cyclic crosslinkers based on monomeric diisocyanates having an aliphatic or cycloaliphatic radical are known per se to the person skilled in the art and are based on e.g. on the monomeric diisocyanates isophorone diisocyanate, 1,4-cyclohexyl diisocyanate, 1,1-methylene-bis (4-isocyanyanocyclohexane), 1,2-bis (4-isocyanatononyl) -3-heptyl-4-pentylcyclohexane and hexamethylene l, 6-diisocyanate. The use of isophorone diisocyanate and hexamethylene-l, 6-diisocyanate for the preparation of the crosslinkers to be used according to the invention is preferred.

 It is also possible to use a cyclic crosslinker based on monomeric diisocyanates obtained from a monomeric aromatic di- or polyisocyanate. The monomeric aromatic di- or polyisocyanate preferably has 6 to 20 carbon atoms, more preferably 6 to 15 carbon atoms. Suitable aromatic monomeric di- or polyisocyanates are e.g. 2,4-diisocyanatotoluene, 2,6-diisocyanatotoluene, 1,5-naphthylene diisocyanate, 4,4'-methylenediphenyl diisocyanate, 1,3-bis (3-isocyanato-4-methylphenyi) -2,4-dioxo diazetidine, N, N'-bis (4-methyl-3-isocyanato-phenyl) urea and tetramethyl xylylene diisocyanate. Of these monomeric aromatic di- or polyisocyanates, 2,4-diisocyanatotoluene, 2,6-diisocyanatotoluene and 4,4'-methylene-bis (phenyl diisocyanate) are preferred. Particularly preferred are 2,6-diisocyanatotoluene and 4,4'-methylene-bis (phenyl diisocyanate).

allophanates:

 In the context of the present invention, allophanates (carbamoylcarbamates) of the general structural formula (1-1) may preferably be used.

These allophanate-containing compounds are, for example, by reacting any urethane-containing starting compounds (containing units of the general formula (R ³ - [M] _p -O-C (= O) -N (H) - [M] _q -R ⁴ ) with monoisocyanates of the general formula R ⁵ - [M] _T -NCO or with diisocyanates of the general formula OCN-A-NCO, where R ^{5 is} preferably an alkyl radical having 1 to 20 carbon atoms or an aryl radical having 6 to 20 carbon atoms or A is a corresponding divalent -C ₂ o alkylene or C ₆ -C ₂ represents o arylene radical. the possibly traversed in such allophanate synthesis urea group-containing intermediate may also be isolated and thus represent a new starting compound. as monoisocyanates suitable for the preparation of the allophanates any aromatic, aliphatic and cycloaliphatic monoisocyanates having 2 to 20 carbon atoms, such as Methyl isocyanate, isopropyl isocyanate, n-butyl isocyanate, n-hexyl isocyanate, cyclohexyl isocyanate, stearyl isocyanate, optionally halogenated phenyl isocyanates, 1-Naphtylisocyanat, optionally chlorinated or fluorinated m-, o-, and p-Toloylisocyanate, p-isopropylphenyl isocyanate, 2,6-diisopropylphenyl isocyanate and p-toluenesulfonyl diisocyanate.

Suitable diisocyanates for the preparation of the allophanates are any desired aromatic, aliphatic and cycloaliphatic diisocyanates containing 6 to 40 carbon atoms, preferably 6 to 15 carbon atoms, such as isophorone diisocyanate, 1,4-cyclohexyl diisocyanate, 1,1-methylenebis (isocyanatohexane), 1 , 2-bis (4-isocyanatononyl) -3-heptyl-4-pentylcyclohexane, hexamethylene-1,6-diisocyanate, 2,4-diisocyanatotoluene, 2,6-diisocyanatotoluene, 1,5-naphthylene diisocyanate, 4,4'-diisocyanate. Methylene diphenyl diisocyanate, 1,3-bis (3-isocyanto-4-methylphenyl) -2,4-dioxodiazetidine, Ν, Ν'-bis (4-methyl-3-isocyanatophenyl) urea and tetramethylxylylene diisocyanate. Preferred of these is hexamethylene 1,6-diisocyanate. Such allophanates as well as their preparation are e.g. in EP 0 000 194 AI, the disclosure of which is included in the present invention by way of reference. The isocyanate used for allophanate formation can be used in an equimolar amount, as well as in excess, based on the urethane groups present in the starting compound in the deficit. In the latter case, the excess isocyanate after completion of the reaction by a method known in the art, such. As distillation or extraction, are separated. It is therefore preferred to use 1.0 to 1.0 mol of isocyanate per 1.0 mol of urethane groups of the starting compound, particularly preferably the use of 0.5 to 1.0 mol of isocyanate. The allophanate or biuret formation of the urethane or urea groups by the monoisocyanates is preferably carried out using catalysts.

With particular preference the crosslinkers used according to the invention are dimers or trimers of monomeric diisocyanates, in particular uretdiones or isocyanurates. Especially preferred trimeric Hexamethylendtisocyanat is used with isocyanurate structure. For blocking isocyanate groups, for example, hydrogen sulfide adducts (carbamoylsulfonates) or oxime adducts can be used. Blocking can be carried out, for example, with sodium disulfide, wherein the adduct can be deblocked again at temperatures of about 100.degree. Further suitable blocking agents are phenols, such as phenol, nonylphenol, cresol, oximes, such as butanone oxime, cyclohexanone oxime, lactams, such as γ-caprolactam, secondary amines, such as diisopropylamine, pyrazoles, such as dimethylpyrazole, imidazoles or triazoles, and malonic and acetic esters. As hydroxyl-containing (H) BR rubbers, any optionally hydrogenated nitrile rubbers may be used in the context of this application, provided that they contain hydroxyl groups. Typically, the hydroxyl group-containing (H) NBR rubbers comprise repeating units derived from at least one conjugated diene, at least one α, β-unsaturated nitrile, at least one copolymerizable hydroxyl group-containing monomer and optionally one or more other copolymerizable monomers, wherein the C = C double bonds in these repeat units in the case of the hydrogenated nitrile rubber ("HNBR") are completely or partially hydrogenated.

Preferably, at least one hydroxyl group of the copolymerizable hydroxyl group-containing monomer is not bonded to the C atom of a carboxy ligand to which the oxygen atom is further bonded by double bond.

Preferred copolymerizable hydroxyl group-containing monomers are hydroxyalkyl (meth) acrylates or copolymerizable vinyl unsaturated monomers containing at least one hydroxyl group, e.g. 4-vinylphenol, into consideration. Preference is given to hydroxyalkyl acrylates and hydroxyalkyl methacrylates in which the C atom number of the hydroxyalkyl groups is 1 to 20, preferably 1 to 12.

Examples of suitable hydroxyl group-containing monomers are 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate, 3-chloro-2-hydroxypropyl (meth) acrylate, 3-phenoxy-2-hydroxypropyl (meth) acrylate, glycerol mono (meth) acrylate, hydroxybutyl (meth) acrylate, 3-chloro-2-hydroxypropyl (meth) acrylate, hydroxyhexyl (meth) acrylate, hydroxyoctyl (meth) acrylate, hydroxymethyl (meth) acrylamide, 2 Hydroxypropyl (meth) acrylate, 3-hydroxypropyl (meth) acrylamide, di (ethylene glycol) itaconate, di (propylene glycol) itaconate, bis (2-hydroxypropyl) itaconate, bis (2-hydroxyethyl) itaconate, bis (2-hydroxyethyl) fumarate, bis (2-hydroxyethyl) maleate, hydroxymethyl vinyl ketone, (4-vinylphenyl) methanol and 4-vinylphenol.

Particularly preferred are hydroxyalkyl (meth) acrylates, in particular hydroxyethyl (meth) acrylate and hydroxypropyl (meth) acrylate, in particular 2-hydroxyethyl methacrylate (HEMA) or 2-hydroxyethyl acrylate (HEA). The proportion of hydroxyl group-containing monomers in the (H) NBR rubber is generally 0.1 to 25 wt .-%, preferably 0.5 to 10 wt .-%, particularly preferably 1.5 to 7 wt .-% and in particular 1 , 5 to 5 wt .-%. The conjugated diene in nitrile rubber can be of any nature. Preference is given to using (C ₄ -C ₆ ) conjugated dienes. Particular preference is given to 1,2-butadiene, 1,3-butadiene, isoprene, 2,3-dimethylbutadiene, piperylene or mixtures thereof. Particularly preferred are 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 preferred optionally hydrogenated nitrile rubber is a polymer having repeating units derived exclusively from (i) one or more conjugated dienes, (ii) one or more (C ₃ -C ₅ ) -α, β-unsaturated nitriles and (iii) one or more copolymerizable hydroxyl group-containing monomers each containing at least one hydroxyl group other than the C atom of a carboxyl group is bound to which further an oxygen atom is bound by double bond.

A particularly preferred optionally hydrogenated nitrile rubber is a polymer having repeating units derived exclusively from (i) a (C ₄ -C ₆ ) conjugated diene, (ii) a (C ₃ -C 5) -α, β-unsaturated nitrile, and (iii) a copolymerizable Hydroxylgruppenhaitigen monomers containing at least one hydroxyl group which is not bonded to the carbon atom of a carboxyl group to which further an oxygen atom is bound by double bond.

A most preferred optionally hydrogenated nitrile rubber is a polymer having repeating units derived exclusively from (i) one or more (C ₄ -C ₆ ) conjugated dienes, (ii) one or more (C ₃ -C 5) -, ß-unsaturated nitriles and (iii) one or more hydroxyalkyl (meth) acrylates.

Particularly preferred is an optionally hydrogenated nitrile rubber having repeating units derived exclusively from (i) butadiene, (ii) acrylonitrile and (iii) one or more hydroxyalkyl (meth) acrylates. A particularly preferred nitrile rubber is a copolymer of acrylonitrile and 1,3-butadiene and HEMA or HEA. A particularly preferred hydrogenated nitrile rubber is a copolymer of acrylonitrile and 1,3-butadiene and also HEMA or HEA in which the C =C double bonds in the repeat units are completely or partially hydrogenated.

As further copolymerizable monomers it is possible, if desired, for example, to use aromatic vinyl monomers, preferably styrene, α-methylstyrene and vinylpyridine, fluorine-containing vinyl monomers, preferably fluoroethylvinylether, fluoropropylvinylether, o-fluoromethylstyrene, vinylpentafluorobenzoate, difluoroethylene and tetrafluoroethylene, or else copolymerizable antiageing monomers, preferably N- ( 4-anilinophenyl) acrylamide, N- (4-anilinophenyl) methacrylamide, N- (4-anilinophenyl) cinnamide, N- (4-anilinophenyl) crotonamide, N-phenyl-4- (3-vinylbenzyloxy) ani! In and N- phenyl-4- (4-vinylbenzyloxy) aniline and non-conjugated dienes, such as 4-cyanocyclohexene and 4-vinylcyclohexene, or else alkynes, such as 1- or 2-butyne.

Alternatively, carboxy group-containing termonomers may be used as further copolymerizable monomers, e.g. α, β-unsaturated monocarboxylic acids, their esters, α, β-unsaturated dicarboxylic acids, their mono- or diesters or their corresponding anhydrides or amides.

Acrylic acid and methacrylic acid may preferably be used as α, β-unsaturated monocarboxylic acids.

It is also possible to use esters of α, β-unsaturated monocarboxylic acids, preferably their alkyl esters and alkoxyalkyl esters. The alkyl esters, in particular C-C are preferably _t s alkyl esters of α, β-unsaturated monocarboxylic acids, particularly preferred in particular C are alkyl, _r Cig alkyl esters of acrylic acid or methacrylic acid, especially methyl acrylate, ethyl acrylate, propyl acrylate, n-butyl acrylate, tert- Butyl acrylate, 2-ethylhexyl acrylate, n-dodecyl acrylate, methyl methacrylate, ethyl methacrylate, butyl methacrylate and 2-ethylhexyl methacrylate. Methoxymethyl acrylate, methoxyethyl (meth) Alkoxyalkyiester of acrylic acid or methacrylic acid, most preferably acrylate, ethoxyethyl (meth) - and alkoxyalkyl esters of α, β-unsaturated monocarboxylic acids, particularly preferred alkoxyalkyl esters of acrylic acid or methacrylic acid, especially C are preferably ₂ -C ₂ acrylate and methoxyethyl (meth) acrylate. It is also possible to use mixtures of alkyl esters, such as those mentioned above, with alkoxyalkyl esters, for example in the form of the abovementioned. It is also possible to use cyanoalkyl acrylate and cyanoalkyl methacrylates in which the C atom number of the cyanoalkyl group is 2-12, preferably α-cyanoethyl acrylate, β-cyanoethyl acrylate and cyanobutyl methacrylate. It is also possible to use fluorine-substituted benzyl-containing acrylates or methacrylates, preferably fluorobenzyl acrylate, and fluorobenzyl methacrylate. It is also possible to use fluoroalkyl-containing acrylates and methacrylates, preferably trifluoroethyl acrylate and tetrafluoropropyl methacrylate. It is also possible to use amino-containing β-unsaturated carboxylic acid esters, such as dimethylaminomethyl acrylate and diethylaminoethyl acrylate.

Further copolymerizable monomers which can also be used are α, β-unsaturated dicarboxylic acids, preferably maleic acid, fumaric acid, crotonic acid, itaconic acid, citraconic acid and mesaconic acid.

It is also possible to use α, β-unsaturated dicarboxylic acid anhydrides, preferably maleic anhydride, itaconic anhydride, citraconic anhydride and mesaconic anhydride. It is also possible to use mono- or diesters of α, β-unsaturated dicarboxylic acids.

These α, β-unsaturated dicarboxylic acid mono- or diesters may, for example, be alkyl, preferably C 1 -C 10 -alkyl, in particular ethyl, n-propyl, isopropyl, n-butyl, tert-butyl, n-pentyl or n-hexyl, alkoxyalkyl, preferably C ₂ -C ₂ alkoxy alkyl, more preferably C ₃ -Cg- alkoxyalkyl, hydroxyalkyl, preferably C ₁₂ hydroxyalkyl, more preferably C2-Q- hydroxyalkyl, cycloalkyl preferably C ₅ -C 12 -cycloalkyl, particularly preferably C ₆ -C 12 -cycloalkyl, alkylcycloalkyl, preferably Q-C 1 -alkylcycloalkyl, particularly preferably C ₇ -C 10 -alkylcycloalkyl, aryl, preferably C ₆ -C ₄ , Aryl mono- or diesters, which in the case of the diester can each also be mixed esters. Particularly preferred alkyl esters of α, β-unsaturated monocarboxylic acids are methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, n-butyl (meth) acrylate, t-butyl (meth) acrylate, hexyl (meth) acrylate , 2-Ethlyhexyl (meth) acrylate, octyl (meth) acrylate, 2-propylheptyl acrylate and lauryl (meth) acrylate. In particular, n-butyl acrylate is used. Particularly preferred alkoxyalkyl esters of the α, β-unsaturated monocarboxylic acids are methoxyethyl (meth) acrylate, ethoxyethyl (meth) acrylate and methoxyethyl (meth) acrylate. In particular, methoxyethyl acrylate is used.

Other esters of the α, β-unsaturated monocarboxylic acids are, for example, polyethylene glycol (meth) acrylate, polypropylene glycol (meth) acrylate, glycidyl (meth) acrylate, Epoxy (meth) acrylate, N- (2-hydroxyethyl) acrylamides, N- (2-hydroxymethyl) acrylamides and urethane (meth) acrylate used.

Examples of α, β-unsaturated dicarboxylic acid monoesters include

 Maleic monoalkyl esters, preferably monomethyl maleate, monoethyl maleate, monopropyl maleate and mono-n-butyl maleate;

 Maleic monocycloalkyl esters, preferably monocyclopentyl maleate, monocyclohexyl maleate and monocycloheptyl maleate;

 Maleic acid monoalkylcycloalkyl esters, preferably monomethylcyclopentyl maleate and monoethylcyclohexyl, eat once;

 Maleic monoaryl ester, preferably monophenylmaleate;

 Maleic acid monobenzyl ester, preferably monobenzyl maleate;

 Fumarsäuremonoalkylester, preferably Monomethylftimarat, monoethyl fumarate, monopropyl fumarate and mono-n-butyl fumarate;

 Fumaric monocycloalkyl esters, preferably monocyclopentyl fumarate, monocyclohexyl fumarate and monocycloheptyl fumarate;

 Fumaric acid monoalkylcycloalkyl ester, preferably monomethylcyclopentyl fumarate and monoethylcyclohexyl fumarate;

 Fumaric monoaryl ester, preferably monophenyl fumarate;

 Fumaric acid monobenzene, preferably monobenzyl fumarate;

 Citraconic monoalkyl esters, preferably monomethyl citraconate, monoethyl acrylate, monopropyl citrate and mono-n-butyl citraconate;

 Citraconic monocycloalkyl esters, preferably monocyclopentyl citraconate, monocyclohexyl citraconate and monocycloheptyl citraconate;

 Citraconsäuremonoalkylcycloalkylester, preferably Monomethylcyclopentylcitraconat and Monoethylcyclohexylcitraconat;

 Citraconsäuremonoarylester, preferably Monophenylcitraconat;

 Citraconic acid monobenzyl ester, preferably monobenzyl citraconate;

 Itaconic acid monoalkyl ester, preferably monomethyl itaconate, monoethyl itaconate, monopropyl itaconate and mono-n-butyl itaconate;

 Itaconic acid monocycloalkyl ester, preferably monocyclopentyl itaconate, monocyclohexyl itaconate and monocycloheptyl itaconate;

 Itaconic acid monoalkylcycloalkyl ester, preferably monomethylcyclopentyl itaconate and monoethylcyclohexyl itaconate;

 Itaconic acid monoaryl ester, preferably monophenyl itaconate;

Itaconic acid monobenzyl ester, preferably monobenzyl itaconate. Mesaconsäuremonoalkylester, preferably Mesaconsäuremonoethylester;

As α, β-unsaturated dicarboxylic acid diesters, the analog diesters can be used based on said monoester groups, wherein the ester groups can also be chemically different.

Radical polymerizable compounds which contain at least two olefinic double bonds per molecule are also suitable as further copolymerizable monomers. Examples of polyunsaturated compounds are acrylates, methacrylates or itaconates of polyols, e.g. Ethylene glycol diacrylate, diethylene glycol dimethacrylate, triethylene glycol diacrylate, butanediol-1,4-diacrylate, propanediol 1,2-diacryate, butanediol-1,3-dimethacrylate, neopentyl glycol diacrylate, trimethylolpropane di (meth) acrylate, trimethylolethane di (meth) acrylate, glycerol di- and triacrylate, pentaerythritol di-, tri- and tetraacrylate or methacrylate, dipentaerythritol tetra, penta- and hexaacrylate or -methacrylate or -itaconate, sorbitol tetraacrylate sorbitol hexamethacrylate, diacrylates or dimethacrylates of 1,4-cyclohexanediol, 1,4-dimethylolcyclohexane , 2,2-bis (4-hydroxyphenyl) propane, of polyethylene glycols or of oligoesters or oligourethanes with hydroxyl end groups. As polyunsaturated monomers it is also possible to use acrylamides, e.g. Methylenebisacrylamide, hexamethylene-1, 6-bisacrylamide, diethylenetriamine tris-methacrylamide, bis (methacrylamidopropoxy) ethane or 2-acrylamido-ethyl acrylate. Examples of polyunsaturated vinyl and AHyl compounds are divinylbenzene, ethylene glycol divinyl ether, diallyl phthalate, allyl methacrylate, diallyl maleate triallyl isocyanurate or triallyl phosphate.

The proportions of conjugated diene and α, β-unsaturated nitrile in the optionally hydrogenated nitrile rubbers can vary widely. The proportion of or the sum of the conjugated dienes is usually in the range of 39.5 to 90 wt .-%, preferably in the range of 48.5 to 85 wt.%, Based on the total polymer. The proportion of hydroxyl-containing monomers is generally 0.1 to 25 wt .-%, preferably 0.5 to 10 wt .-%, particularly preferably 1.5 to 7 wt .-% and in particular 1.5 to 5 parts by weight. %, based on the total polymer. The proportion of or the sum of the α, β-unsaturated nitriles is usually 9.5 to 60 wt .-%, preferably 13.5 to 50 wt .-%, based on the total polymer. The proportions of the monomers in each case add up to 100% by weight. Depending on the type of the termonomer (s), the additional monomers may be present in amounts of from 0 to 50% by weight, based on the total polymer. In this case, corresponding proportions of the conjugated dienes and / or of the α, β-unsaturated nitriles are replaced by the proportions of the additional monomers, the proportions of all monomers adding up to 100% by weight in each case. The nitrile rubbers according to the invention, which may also be completely or partially hydrogenated, have Mooney viscosities (ML (1 + 4 at 100 ° C.)) of usually 10 to 160, preferably 15 to 150 Mooney units, particularly preferably 20 to 150 Mooney Units and in particular 25 to 145 Mooney units on. The values for the Mooney viscosity (ML 1 + 4 at 100 ° C.) are determined in each case by means of a shear disk viscometer in accordance with DIN 53523/3 or ASTM D 1646 at 100 ° C.

The nitrile rubbers used furthermore have a polydispersity PDi = M _w / M _n , where M _{w is} the weight average and M _n the number average molecular weight, in the range of preferably 1, 0-6.0 and preferably in the range of 1.5-5 , 0th

The glass transition temperatures of the optionally hydrogenated nitrile rubbers to be used according to the invention are in the range from -80 ° C. to + 20 ° C., preferably in the range from -70 ° C. to 10 ° C. Metathesis and hydrogenation:

 As an alternative to the preparation of the nitrile rubber, it is also possible for the preparation of the nitrile rubber to be followed either by (i) a metathesis reaction or (ii) a metathesis reaction and a subsequent hydrogenation or (iii) only one hydrogenation. These metathesis or hydrogenation reactions are both well known to the skilled person and described in the literature. The metathesis is known, for example, from WO-A-02/100941 and WO-A-02/100905 and can be used for molecular weight reduction. The hydrogenation can be carried out using homogeneous or heterogeneous hydrogenation catalysts.

The catalysts used are usually based on rhodium, ruthenium or titanium, but it is also possible to use platinum, iridium, palladium, rhenium, ruthenium, osmium, cobalt or copper either as metal or preferably in the form of metal compounds (see, for example, US Pat 3,700,637, DE-A-25 39 132, 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 homogeneous phase hydrogenation are described below and are also known from DE-A-25 39 132 and EP-A-0 471 250

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 wherein M is ruthenium or rhodium, R ^{1 are the} same or different and represent a C Cg alkyl group, a GrCg cycloalkyl group, a C6-C15 aryl group or a C7-C15 aralkyl group. B is phosphorus, arsenic, sulfur or a sulfoxide group S = O, X is hydrogen or an anion, preferably halogen and particularly preferably chlorine or bromine, 1 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 (II) chloride and tris (dimethyl sulfoxide) rhodium (III) chloride and tetrakis ( triphenylphosphine) -rhodium-hydride of the formula (CeH ^ P ^ RhH and the corresponding compounds in which the triphenylphosphine has been wholly or partly replaced by tricyclohexylphosphine The catalyst can be used in small amounts, in the range of 0.01-1 % By weight, preferably in the range from 0.03-0.5% by weight and particularly preferably in the range from 0.1-0.3% by weight, based on the weight of the polymer, is usually suitable to use together with a co-catalyst which is a ligand of the formula RlmB, wherein Rl, m and B are the have before mentioned for the catalyst meanings. 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 of co-catalysts can be found, for example, in US Pat. No. 4,631,315. Preferred co-catalyst is triphenylphosphine. The co-catalyst is preferably used in amounts in a range of 0.3-5 wt.%, Preferably in the range of 0.5-4 wt.%, Based on the weight of the nitrile rubber to be hydrogenated. Furthermore, the weight ratio of the rhodium-containing catalyst to the cocatalyst is preferably in the range from 1: 3 to 1:55, particularly preferably in the range from 1: 5 to 1:45, based on 100 parts by weight of the nitrile rubber to be hydrogenated, it is appropriate to use 0, 1 to 33 parts by weight of the co-catalyst, preferably 0.5 to 20 and very 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.

The practice of this hydrogenation is known from US-A-6,683,136. It is usually carried out by subjecting the nitrile rubber to be hydrogenated in a solvent such as toluene or monochlorobenzene at a temperature in the range of 100 to 150 ° C and a pressure in the range of 50 to 150 bar for 2 to 10 hours with hydrogen. In the context of this invention, hydrogenation or "hydrogenation" is understood as meaning a conversion of the C =C double bonds present in the starting nitrile rubber to at least 50%, preferably 70-100%, particularly preferably 80-100%. When heterogeneous catalysts are used They are usually supported catalysts based on palladium, which are supported for example on carbon, silica, calcium carbonate or barium sulfate.

The invention also relates to hydroxyl group-containing HNBR rubbers characterized by repeating units derived exclusively from (i) one or more conjugated dienes, (ii) one or more α, β-unsaturated nitriles and (iii) one or more copolymerizable hydroxyl group-containing monomers, respectively containing at least one hydroxyl group which is not bonded to the C atom of a carboxyl group to which an oxygen atom is further bonded by double bond.

The invention further provides vulcanizable compositions comprising at least one optionally hydrogenated hydroxyl-containing nitrile rubber and at least one crosslinker of the general formula (I), (Ii), (III) or (IV) which contains at least two isocyanate groups. Optionally, these viilkanisierbaren compositions contain at least one other crosslinker, which is different from those of the general formulas (I) to (IV).

The amount of the crosslinker of the general formula (I), (II), (III) or (IV) or (1-1) to (1-6) containing at least two isocyanate groups is usually in the range of 0.2 up to 25 phr, preferably from 1 to 20 phr, more preferably in the range from 1.5 to 15 phr and in particular in the range from 2 to 10 phr, based on the hydroxyl-containing optionally hydrogenated nitrile rubber. For the purposes of the invention, "phr" means In this case, the vulcanizable compositions according to the invention contain at least 33% by weight, preferably at least 35% by weight, particularly preferably at least 40% by weight. % of the hydroxyl group-containing (H) NBR rubber, based on the weight of the total composition, Also possible are embodiments in which the vulcanizable composition contains a proportion of the hydroxyl group-containing (H) NBR Having rubbers of at least 42 wt.%, In particular at least 45 wt.% Based on the weight of the total composition. As is well known, the vulcanizable compositions according to the invention contain no or only a small amount of solvent, based on the hydroxyl group-containing (H) NBR rubber. Vulcanizable compositions containing not more than 15% by weight of solvent, preferably not more than 10% by weight, more preferably not more than 5% by weight, very preferably not more than 2% by weight, and most preferably not, have proven useful more than 1% by weight of solvent, in each case based on the hydroxyl group-containing (H) NBR rubber. Under "solvent" are again water, any organic solvents and any other substances that solve hydroxyl-containing (H) NBR rubber, or any mixtures of the above to understand.

The vulcanizable compositions according to the invention particularly preferably contain only the abovementioned maximum amounts of water or organic solvents such as methyl acetate, n-butyl acetate, t-butyl acetate, acetone, ethyl acetate, isopropyl acetate, isobutyl acetate, tetrahydrofuran, n-methylpyrrolidone, aliphatic hydrocarbons such as heptane, dimethylformamide, Diisobutyl ketone (DIBK), methyl isoamyl ketone, monochlorotoluene, p-chlorobenzotrfluoride (PCBTF), VM & P Naptha, xylene, toluene, MEK and MIBK. In particular, the inventive vulcanizable compositions contain only the abovementioned maximum amounts of water or ΜΓΒΚ. This applies equally to the use according to the invention. The vulcanizable compositions according to the invention are thus not liquid.

Optionally, such vulcanizable compositions may also contain one or more additives familiar to the person skilled in the rubber (cf. Ullmann's Encyclopedia of Industrial Chemistry, VCH Verlagsgesellschaft mbH, D-69451 Weinheim, 1993, Vol. A 23 "Chemicals and Additives", p. 417). These include anti-aging agents, anti-reversion agents, light stabilizers, antiozonants, processing aids, reinforcing materials, mold release agents, plasticizers, mineral oils, tackifiers, blowing agents, dyes, pigments, waxes, resins, extenders, organic acids, anti-curl agents, metal oxides, fillers and filler activators.

As possible further crosslinkers, which are different from the compounds of the general formulas (I) - (IV), it is possible, for example, to use peroxides, sulfur or sulfur donors. Suitable peroxides are bis (2,4-dichlorobenzyl) peroxide, dibenzoyl peroxide, bis (4-chlorobenzoyl) peroxide, 1,1-bis (t-butylperoxy) -3,3,5-trimethylcylohexane, tert-butyl perbenzoate, 2, 2 bis (t-butylperoxy) butene, 4,4-di-tert-butyl peroxynonylvalerate, dicumyl peroxide, 2,5-dimethyl-2,5-di (t- butylperoxy) hexane, tert-butylcylic peroxide, 1,3-bis (i-butylperoxyisopropyl) benzene, di-t-butyl peroxide and 2,5-dimethyl-2,5-di (t-butylperoxy) hexyn-3.

It may be advantageous, in addition to these peroxidic Vernetzem to use other additives, with the aid of the crosslinking yield can be increased: For example, triallyl isocyanurate, triallyl cyanurate, trimethylolpropane tri (meth) acrylate, triallyl trimellitate, ethylene glycol dimethacrylate, butanediol dimethacrylate, trimethylolpropane trimethacrylate, zinc acrylate , zinc diacrylate, zinc methacrylate, zinc dimethacrylate, 1,2-polybutadiene or N, N ^{'-m-phenylene} dimaleimide suitable.

As further crosslinkers sulfur can also be used in elemental soluble or insoluble form or sulfur donors. Sulfur donors include, for example, dimorpholyl disulfide (DTDM), (MBSS), caprolactam disulfide, dipentamethylene thiuram tetrasulfide (DPTT), and tetramethyl thiuram disulfide (TMTD). If sulfur or a sulfur donor is added to the vulcanizable composition as further crosslinking agents, it may be advisable to use further additives with the aid of which the crosslinking yield can be increased. In principle, however, the crosslinking can also be carried out with sulfur or sulfur donors as the only further crosslinker in addition to the crosslinkers of the general formulas (I) to (IV) to be used according to the invention.

Conversely, the crosslinking of the hydroxyl-containing optionally hydrogenated nitrile rubbers can also be carried out only in the presence of the abovementioned additives, i. without the addition of elemental sulfur or sulfur donors, but of course continue in the presence of at least one crosslinker of the general formulas (I) to (IV).

As additives with the aid of which the crosslinking yield can be increased with the additional use of sulfur or sulfur donors, e.g. Dithiocarbamates, thiurams, thiazoles, sulfenamides, xanthogenates, bi- or polycyclic amines, guanidine derivatives, ditheaphosphates, caprolactams and thiourea derivatives.

As dithiocarbamates can be used, for example: ammonium dimethyldithiocarbamate, sodium diethyldithiocarbamate (SDEC), Natriumdibutyl-dithiocarbamate (SDBC), Zinkdimethyl- dithiocarbamate (ZD C), zinc diethyldithiocarbamate (ZDEC), zinc dibutyldithiocarbamate (ZDBC), zinc ethylphenyldithiocarbamate (ZEPC), zinc dibenzyldithiocarbamate (ZBEC), zinc Penta methylene dithiocarbamate (Z5MC), tellurium diethyldithiocarbamate, nickel dibutyldithiocarbamate, nickel dimethyldithiocarbamate and zinc diisononyl dithiocarbamate. As thiurams, there may be used, for example, tetramethylthiuram disulfide (TMTD), tetramethylthiuram monosulfide (TMTM), dimethyldiphenylthiuram disulfide, tetrabenzylthiuram disulfide, dipentamethylenethiuram tetrasulfide and tetraethylthiuram disulfide (TETD).

Examples of suitable thiazoles are 2-mercaptobenzothiazole (MBT), dibenzothiazyl disulfide (MBTS), zinc mercaptobenzothiazole (ZMBT) and copper 2-mercaptobenzothiazole.

Examples of sulfenamide derivatives which can be used are: N-cyclohexyl-2-benzothiazyl sulfenamide (CBS), N-tert-butyl-2-benzthiazyl sulfenamide (TBBS), N, N'-dicyclohexyl] -2-benzthiazyl sulfenamide (DCBS), 2-Mo ^ holothiobenzothiazole (MBS), N-oxydiethylenethiocarbamyl-N-tert-butylsulfenamide, and oxydiethylenethiocarbamyl-N-oxyethylenesulfenamide.

Examples of xanthates which can be used are: sodium dibutylxanthogenate, zinc isopropyldibutylxanthogenate and zinc dibutylxanthogenate,

Examples of bi- or polycyclic amines which may be used are: 1,8-diazabicyclo [5.4.0] undec-7-ene (DBU), 1,1,5-diazabicyclo [4.3.0] non-5-ene (DBN), 1,4-diazabicyclo [2.2.2] octane (DABCO), l, 5,7-triazabicyclo [4.4.0] dec-5-ene (TBD) and 7-methyl-1,5,7-triazabicyclo [4.4. 0] dec-5-ene.

Examples of guanidine derivatives which can be used are: diphenylguanidine (DPG), di-o-tolylguanidine (DOTG) and o-tolylbiguanide (OTBG).

Examples of dithiophosphates which can be used are zinc dialkydithiophosphates (chain length of the alkyl radicals C ₂ to C ₆ ), copper dialkyldithiophosphates (chain length of the alkyl radicals C ₂ to Cie) and dithiophosphoryl polysulfide.

For example, dithiobiscaprolactam can be used as caprolactam.

 As thiourea derivatives, for example, Ν, Ν'-diphenylthiourea (DPTU),

Diethylthiourea (DETU) and ethylenethiourea (ETU).

Also suitable as additives are, for example: zinc diamine diisocyanate, hexamethylenetetramine, 1,3-bis (citraconimidomethyl) benzene and cyclic disulfanes.

In the case of carboxyl- and hydroxyl-containing nitrile rubbers, a polyamino crosslinking method can be used as a further crosslinking method, the polyamines used contain at least 2 amino groups, or these are formed in situ during vulcanization. Examples of suitable polyamines are aliphatic polyamines, such as hexamethylenediamine, hexamethylenediamine carbamate, hexamethylenediamine-cinnamaldehyde adducts or hexamethylenediamine dibenzoate salts, or aromatic polyamines, such as 2,2-bis (4- (4-aminophenoxy) phenyl) propane, 4,4'-methylenediamine , m-phenylenediamine, p-phenylenediamine or 4,4'-methylenebis (o-chloroaniline). Reagents having at least 2 hydrazide units such as isophthalic dihydrazide, adipic dihydrazide or sebacic dihydrazide are also suitable.

The additives mentioned as well as the crosslinking agents can be used individually or in mixtures. The following additional substances for crosslinking the hydrogenated optional hydroxyl-containing nitrile rubbers are preferably used: sulfur, 2-mercaptobenzothiazole, tetramethylthiuram disulfide, tetramethylthiuram monosulfide, zinc dibenzyldithiocarbamate, methylenthiuramtetrasulfid dipentaerythritol, Zinkdialkydithiophosphat, Dimoφholyldisulfϊd, Tellurdiethyldithio- carbamate, nickel dibutyldithiocarbamate, Zinkdibutyldäthiocarbamai, zinc dimethyldithiocarbamate and Dithiobiscaprolactam.

In addition, scorch retarders can be used for additional crosslinks. These include cyclohexylthiophthalimide (CTP), Ν, Ν'-dinitrosopentamethylenetetramine (DNPT), phthalic anhydride (PTA) and diphenylnitrosamine. Cyclohexylthiophthalimide (CTP) is preferred.

In the case of crosslinking, it may also be expedient to use further inorganic or organic substances, e.g. Zinc oxide, zinc carbonate, lead oxide, magnesium oxide, saturated or unsaturated organic fatty acids and their zinc salts, polyalcohols, aminoalcohols, e.g. Triethanolamine and amines, e.g. Dibutylamine, dicyclohexylamine, cyclohexylethylamine and polyetheramines.

In addition to at least one compound of the general formula (I) - (IV), no or only insignificant amounts of further crosslinkers are preferably used in the vulcanizable composition. If more are used, the total amount of all present in the vulcanizable composition crosslinker (ie, the invention of the general formula (I) - (IV) plus other crosslinkers) including the crosslinking yield of increasing additives and scorch delay is usually in the range of 0.5 to 30 phr , preferably 1 to 23, particularly preferably 1.5 to 18 phr, very particularly preferably 2 to 15 phr and in particular 3 to 12 phr, based on the hydroxyl-containing optionally hydrogenated Nitrilkautsch.uk. In a preferred embodiment, it is vulcanizable compositions which additionally contain at least one filler.

As fillers, for example, carbon black, silica, barium sulfate, titanium dioxide, zinc oxide, calcium oxide, calcium carbonate, magnesium oxide, alumina, iron oxide, aluminum hydroxide, magnesium hydroxide, aluminum silicates, diatomaceous earth, talc, kaolins, bentonites, carbon nanotubes, Teflon (the latter preferably in powder form), or Silicates are used.

Suitable filler activators are, in particular, organic silanes, for example vinyltrimethyloxysilane, vinyldimethoxymethylsilane, vinyltriethoxysilane, vinyltris (2-methoxyethoxy) silane, N-cyclohexyl-3-aminopropyltrimethoxysilane, 3-aminopropyltrimethoxysilane, methyltrimethoxysilane, methyltriethoxysilane, dimethyldimethoxysilane, dimethyldiethoxysilane, trimethylethoxysilane, isooctyltrimethoxysilane Isooctyltriethoxysilane, hexadecyltrimethoxysilane or (octadecyl) methyldimethoxysilane into consideration. Further filler activators are ethanolamine, trimethylolpropane, hexanetriol or polyethylene glycols having molecular weights of 74 to 10,000 g / mol. The amount of filler activators is usually 0 to 10 phr, based on 100 phr of the optionally hydrogenated nitrile rubber.

As anti-aging agents it is possible to add phenolic, aminic and other anti-aging agents.

Suitable phenolic antioxidants are alkylated phenols, styrenated phenol, hindered phenols such as 2,6-di-tert-butylphenol, 2,6-di-ter / -butyl-p-cresol (BHT), 2,6-di-tert .- Butyl-4-ethylphenoi, sterically hindered phenols containing ester groups, thioether-containing sterically hindered phenols, 2,2'-methylenebis (4-methyl-6-rt-butylphenol) (BPH) and sterically hindered thiobisphenols.

If a discoloration of the rubber is of no importance, also aminic aging inhibitor z. B. mixtures of diaryi-p-phenylenediamines (DTPD), octylated diphenylamine (ODPA), phenyl-a-naphthylamine (PAN), phenyl-ß-naphthylamine (PBN), preferably those based on phenylenediamine used. Examples of phenylenediamines are N-isopropyl-N-phenyl - /? - phenylenediamine, N- 1, 3 -dimethylbutyl-N'-phenyl / j-phenylenediamine

(6PPD), N-l, 4-dimethylpentyl-N-phenyl- / j-phenylenediamine (7PPD), NN'-bis-l, 4- (l, 4-dimethylpentyl) - / J-phenylenediamine (77PD), etc. Other anti-aging products include phosphites such as tris- (nonylphenyl) phosphite, polymerized 2,2,4-trimethyl-1,2-dihydroquinoline (TMQ), 2-mercaptobenzimidazole (MBI), methyl-2-mercaptobenzimidazole (MMBI), zinc methylmercaptobenzimidazole ( ZMMBI). The phosphites are generally used in combination with phenolic anti-aging agents. TMQ, MBI and MMBI are mainly used for NBR types, which are vulcanized peroxide additionally to the isocyanate crosslinking.

Suitable mold release agents are, for example: saturated and partially unsaturated fatty and oleic acids and derivatives thereof (fatty acid esters, fatty acid salts, fatty alcohols, fatty acid amides) which are preferably used as a mixing component, furthermore products which can be applied to the mold surface, for example products based on low molecular weight silicone compounds , Products based on fluoropolymers and products based on phenolic resins. The mold release agents are used as a blend component in amounts of about 0 to 10 phr, preferably 0.5 to 5 phr, based on 100 phr of the hydroxyl-containing optionally hydrogenated nitrile rubber.

It is also possible to reinforce with reinforcements (fibers) made of glass, according to the teaching of US Pat. No. 4,826,721, and reinforcing by cords, fabrics, fibers of aliphatic and aromatic polyamides (Nylon®, Aramid®), polyesters and natural fiber products.

Preferably, the nitrile rubber composition of the present invention is free of tin-containing compounds.

Gegenstaad of the present invention, a method for producing the vulcanizable compositions by mixing the ingredients and a process for the preparation of vulcanizates, further characterized in that the aforementioned composition is crosslinked with heating, and the vulcanizates thus obtainable. The preparation of the compositions and their crosslinking can be carried out by customary processes. EXAMPLES:

The nitrogen content for determining the acrylonitrile content (ACN content) is determined in the optionally hydrogenated hydroxyl-containing nitrile rubbers according to the invention in accordance with DIN 53 625 according to Kjeldahl. Due to the content of polar comonomers, the nitrile rubbers are usually soluble in methyl ethyl ketone at 20 ° C> 85 wt.%. The determination of the glass transition temperature, as well as their so-called onset and offset points by means of differential scanning calorimetry (DSC) according to ASTM E 1356-03 and according to DIN 1 1357-2.

The determination of the microstructure and the termonomer content of the individual polymers was carried out by means of ^J H NMR (device: Bruker DPX400 with software XWIN-NMR 3.1, measuring frequency 400 MHz, solvent CDC1 ₃ ).

The values for the Mooney viscosity (ML 1 + 4 @ 100 ° C.) are determined in each case by means of a shear disk viscometer in accordance with DIN 53523/3 or ASTM D 1646 at 100 ° C.

The determination of the MSR (Mooney Stress Relaxation) is carried out in each case by means of a shear disk viscometer according to ISO 289-4: 2003 (E) at 100 ° C.

The course of vulcanization in the MDR and its analytical data were measured on a Monsanto rheometer MDR 2000 according to ASTM D5289-95.

The compression set ("DVR") at the indicated temperature was measured according to DIN 53517.

Shore A hardness was measured according to ASTM-D2240-81.

The tensile tests for determining the stress as a function of the deformation were carried out in accordance with DIN 53504 or ASTM D412-80.

 The abbreviations given in the following tables have the following meanings:

"RT" room temperature (23 ± 2 ° C)

 , Tens Tensile Strength (JS), tensile stress, measured at RT

 "Elongation at break", Elongation at break, measured at RT

 "M50" modulus at 50% elongation, measured at RT

 "Ml 00" modulus at 100% elongation, measured at RT

 "M300" modulus at 300% elongation, measured at RT

 "S min" is the minimum torque of the cross-linking isotherm

 "S max" is the maximum torque of the cross-linking isotherm

 "Delta S" is equal to "S max - S min"

 »Tio is the time when 10% of S max is reached

is the time when 50% of S max is reached "Tgo" is the time when 90% of S max is reached

 , 5 "is the time when 95% of S max is reached

 "TS2" means the time until the Mooney viscosity has increased by two units

 Comparison to the starting point

The following substances were used in the examples:

 The following chemicals were purchased as commercial products of the companies specified or come from production plants of the specified companies.

Addolink ^® TT dimeric toluene diisocyanate with uretdione structure (commercial product of

 Rheinchemie Rheinau GmbH)

Corax ^® N550 / 30 carbon black (commercial product of Evonik Degussa)

Desmodur ^® N3300 trimeric hexamethylene diisocyanate with cyanurate structures (commercial product of Bayer Material Science AG)

Diplast ^® TM 8-10 / ST trioctylmellitate (commercial product of Lonza SpA)

TAIC 70 triallyl isocyanurate (commercial product of ettlitz Chemie GmbH & Co.)

LUVOMAXX ^® CDPA p-cumyl (commercial product of Lehmann & Voss) Maglite ^® DE magnesium oxide (commercial product Hallstar Company)

Mixture Winstay ^® 29 / Naugawhite: mixture of 25 g Sorbilene Mix (mixture of sorbitan esters and ethoxylated sorbitan esters) of Lamberti, 38 g Naughawhite (2,2'-methylenebis (6-nonyl-p-cresol)) of Chemtura, 125 g Wingstay ^® 29

(styrenated diphenylamine) from Eliokem, and 63 g of water ^® PERKADOX 14-40 di- (tert-butylperoxyisopropyl) benzene supported on silica & whiting (40% active ingredient) (commercial product from Akzo Nobel Chemicals GmbH) "premix solution Fe (II) S0 ₄ "contains 0.986 g Fe (II) S0 ₄ * 7 H ₂ 0 and 2.0 g RongaIit ^{® ®} C in 400 g of water Rongalit C sodium salt of a Sulfmsäurederivates t-DDM (BASF SE commercial product): tertiary dodecylmercaptan; LANXESS Germany GmbH

Texapon.RTM ^® -12: sodium lauryl sulfate (a product of Cognis GmbH)

Trigonox ^® NT 50 p-menthane hydroperoxide (Handeisprodukt of Akzo-Degussa)

Vulkanox ^® ZMB2 / C5: zinc salt of 4- and 5-methyl-2-mercaptobenzimidazole (commercial product of LANXESS Deutschland GmbH)

I Preparation of the Nitrile Rubbers A, B, C (Inventive Examples)

The preparation of the nitrile rubbers A, B, C used in the following examples series was carried out according to the base formulation given in Table 1, all starting materials in parts by weight based on 100 parts by weight of the monomer mixture being indicated. Table I also lists the respective polymerization conditions. Table 1:

The preparation of the nitrile rubbers was carried out batchwise in a 5 l autoclave with stirrer. The autoclave batches each used 1.25 kg of the monomer mixture and a total amount of water of 2.1 kg and EDTA in an equimolar amount relative to the Fe-II. From this amount of water, 1.9 kg were introduced with the emulsifier in an autoclave and rinsed with a stream of nitrogen. Thereafter, the destabilized monomers and the amount of the molecular weight regulator t-DDM indicated in Table 1 were added, and the reactor was sealed. After thermostatting of the contents of the reactor, the polymerizations by the addition of the premix solutions of para-menthane hydroperoxide (Trigonox ^® NT50) were started. The course of the polymerization was followed by gravimetric conversion determinations. When the yields given in Table 1 were reached, the polymerization was stopped by addition of an aqueous solution of diethylhydroxylamine. Unreacted monomers and other volatiles were removed by steam distillation.

The dried NBR rubbers were characterized by the Mooney viscosity, their MSR, the ACN content and the Glasübergangstemeratur and the content of the hydroxyl-containing termonomer by ^! H-NMR analysis determined (Table 2). Table 2: Nitrile Rubbers A, B, C; properties

Π Preparation of Vulcanizates VI to V9 of the Nitrile Rubbers A, B, C (Preparation Examples

 The vulcanizates VI to V9 were prepared from the nitrile rubbers A, B and C as described below. The components of the mixtures are based on 100 parts of nitrile rubber and given in Tables 3, 7 and 11. The blends were made in a Banbury mixer. For this purpose, the rubber and all the additives listed in Table 3, 7 or 1 1 were mixed for a total of 4 minutes at a maximum temperature of up to 120 ° C. For this purpose, the rubber was introduced into the mixer, after 1 minute all further additives were added and after 2 more minutes a sweeping step was carried out. After a total of 4 minutes, the rubber was ejected from the mixer. The compound was vulcanized at a temperature of 170 ° C for 30 minutes.

 Table 3: Vulcanizates V1-V3; composition

The vulcanizates obtained had the properties given in Tables 4 to 6: Table 4: Vulcanizates V1-V3; Vulcanization course in MDR (170 ° C / 30min)

Corresponding to the proportions of hydroxyl-containing monomers in the polymers A-C is the level of the respective maximum torque. All crosslinks were used without the addition of heavy metal compounds as catalyst, e.g. organic tin compounds, carried out.

 Table 5: Vulcanizates V1-V3; vulcanizate

The polymers of the invention are characterized in their vulcanizates by a tensile stress and very high modulus values at 100% elongation.

Table 6: Vulcanizates V1-V3; Compression set measured at RT or 100 ° C

Due to the ratio between crosslinking agent and hydroxyl-containing termonomer, elongation at break and maximum torque in the vulcanizate can be adjusted without difficulty with a simultaneously good compression set. Table 7: Vulcanizates V4-V7; composition

The vulcanizates obtained had the properties given in Tables 8 to 10: TABLE 8 Vulcanizates V4-V7M; Vulcanization course in MDR (170 ° C / 30min)

Corresponding to the proportion of the hydroxyl-containing monomer in the polymers to the ratio of the dimeric diisocyanate is the level of the respective maximum torque. All crosslinks were used without the addition of heavy metal compounds as catalyst, e.g. organic tin compounds, performed.

Table 9: Vulcanizates V4-V7; properties

The polymers according to the invention lead to vulcanizates with high tensile stress and very high modulus values at 100% elongation relative to the elongation at break. Table 10: Vulcanizates V4-V7; Compression set at RT or 10G ° C

In addition to crosslinking by means of dinieren diisocyanates with uretdione structure crosslinking with trimeric hexamethylene diisocyanates were carried out with cyanurate structures.

Table 11: Vulcanizates V8-V9; composition

The vulcanizates obtained had the properties given in Tables 12 to 14: TABLE 12 Vulcanizates V8 and V9; Vulcanization course in MDR (170 ° C / 40min)

Corresponding to the proportions of crosslinker is the level of the respective maximum torque. All crosslinks were carried out without the addition of heavy metal compounds as catalyst, such as z, B, organic tin compounds. Table 13: Vulcanizates V8 and V9; properties

Table 14: Vulcanizates V8 and V9; Compression set at RT, 100 ° C, 150 ° C

 The vulcanizates of the invention are characterized by a very low compression set even at unusually high temperatures of 150 ° C for NBR.

ΠΙ Production of hydrogenated nitrile rubbers H BR 1 and HNBR 2 by hydrogenation

The nitrile rubber "NBR" used as starting material for the hydrogenation contained repeat units of acrylonitrile, butadiene and with a hydroxyl group-containing monomer (NBR 1) or without (NBR 2, comparative experiment) in the amounts indicated in the following Table 15. He had a Mooney viscosity as shown in Table 5.

 TABLE 15 NBR 1 (Inventive) and NBR 2 (Comparison) used for the Hydrogenation

In a high-pressure reactor, a solution of NBR 1 or NBR 2 with a solids content of 12% in monochlorobenzene ("MCB") was introduced as a solvent and to 138 ° C with stirring heated at 600 / min. After establishing a stable temperature, a solution of 0.06 phr Wilkinson's catalyst and 1.0 phr of triphenylphosphine ("TPP") was introduced into MCB as cocatalyst and hydrogen was introduced into the reactor to a pressure of 85 bar The polymer solution was then discharged from the reactor and coagulated using steam in accordance with a known method, and the isolated polymer was then dried.

IV Preparation of vulcanizable compositions

 The components of the vulcanizable composition shown in Table 16 were blended in a Banbury mixer by conventional blending as described above. The polymer composition was then vulcanized at 180 ° C for 20 minutes and annealed for 4 hours at 175 ° C.

The properties of HNBR vulcanizates, as shown in Tables 17 and 18 and shown in Figure 1, demonstrate superiority in crosslink density, increased modulus 100, and increased tensile strength of HNBR 1 compared to HNBR 2. This leads to significant practical benefits Benefits in various dynamic applications, such as conveyor belt and sealing applications, where increased dynamic properties are required of the vulcanizates.

Table 16: Formulation of vulcanizable compositions. Examples Q 1-2

In Table 16, the amounts of all other components are given in "phr", ie parts by weight per 100 parts of rubber component. Table 17; HNBR vulcanizates Q 1 and Q 2; Physical Properties

 Table 18: HNBR Vulcanizates Q 1 and Q 2; MDR values at 180 ° C

 Figure 1 shows the MDR at 180 ° C for the HNBR vulcanizates of Examples Ql and Q2.

 HNBR 1 is the curve in Figure 1 above, the curve of HNBR 2 is below.

Claims

Patentanspräche

Use of compounds of the general formula (I), (II), (III) or (IV) as crosslinkers for hydroxyl group-containing (H) NBR rubbers, wherein

[M] _p -R ³ , NH- [M] _P -R ³

R ² H

or R ¹ and R ² together represent a single bond or one of the following groups

 wherein

 n is an integer from 1 to 4 and

 m = 4-n

or

 wherein in the general formulas (I), (II), (III) and (IV)

R ³ , R ⁴ , R ^{s are} each the same or different and denote H or a radical containing one or more of the following groups, a saturated, mono- or polyunsaturated carboxylic or heterocyclyl radical, straight-chain or branched Aikyl, aryl, heteroaryl, arylalkyl, heteroarylalkyl, alkoxy, aryloxy, heteroaryloxy, amino, amido, hydroxyimino, carbamoyl, alkoxycarbonyl, F, Cl, Br, I, Hydroxy, phosphonato, phosphinato, alkylthio, arylthio, sulfanyl, thiocarboxy, sulfinyl, sulfono, sulfino, sulfeno, sulfonic acids, sulfamoyl, silyl, silyloxy, nitrile, sulfanyl, hydroperoxycarbonyl, hydroperoxy, thiocarboxy, dithiocarboxy, hydroxyimino, nitro, nitrosyl, carbonyl, Carboxy, oxycarbonyl, oxysulfonyl, oxo, thioxo, borate, selenate, epoxy, cyanate, thiocyanate, isocyanate, thioisocyanate or isocyanide,

 M is repeating units of one or more mono- or polyunsaturated monomers comprising conjugated or non-conjugated dienes, alkynes and vinyl compounds, or a divalent structural element which derives polymers comprising polyethers, in particular polyalkylene glycol ethers and polyalkylene oxides, polysiloxanes, polyols, polycarbonates , Polyurethanes, polyisocyanates, polysaccharides, polyesters and polyamides, and

 p, q, r are the same or different and are in the range of 0 to 10,000,

 and wherein the compounds of general formula (I), (II), (ΠΤ) and (IV) each contain at least two isocyanate groups.

2. Use according to claim 1, characterized in that the compounds of the general formula (I) have at least one allophanate, biuret, uretdione, uretonimine, bridged carbamate, carbodiimide, isocyanurate, iminooxadiazinedione or oxadiazinetrione structure ,

3. Use according to claim 1, characterized in that one or more compounds of the general formulas (1-1) to (1-6) are used as crosslinking agents,

where in the general formulas (II) to (1-6) the radicals R ¹ , R ² , R ³ , R ⁴ , R ⁵ and M and p, q, r have the same meanings as in claim 1.

4. Use according to one of claims 1 to 3, characterized in that it is the dimer or trimer of diisocyanates in the compound of general formula (I).

Use according to one of claims 1 to 4, characterized in that the crosslinker is used in the absence of tin-containing compounds.

Use according to one of claims 1 to 5, characterized in that in this either no or not more than 15 wt.% Solvent, preferably not more than 10 wt.%, Particularly preferably not more than 5 wt.%, Very particularly preferably not more than 2% by weight and especially preferably not more than 1% by weight of solvent, in each case based on the hydroxyl-containing (H) NBR rubber used are present.

A vulcanizable composition containing at least one hydroxyl group-containing (H) NBR rubber and at least one crosslinker as defined in any one of claims 1 to 4.

Vulcanisable composition according to claim 7, characterized in that the (H) NBR rubber repeating units derived from at least one conjugated diene, at least one α, β-unsaturated nitrile, at least one copolymerizable hydroxyl group-containing monomer and optionally one or more other copolymerizable monomers and the C = C double bonds are completely or partially hydrogenated in the case of HNBR.

Vulcanisable composition according to claim 7 or 8, characterized in that in the (H) NBR rubber, the copolymerizable hydroxyl-containing monomer is selected from the group consisting of hydroxyalkyl (meth) acrylates.

Vulcanisable composition according to one of claims 7 to 9, characterized in that in the (H) NBR rubber additionally repeating units of a copolymerizable crosslinking monomer are present.

Vulcanizable composition according to claim 10, characterized in that the copolymerisable crosslinking monomer is a triacrylate.

Vulcanisable composition according to any one of claims 7 to 11, characterized in that it is free of tin-containing compounds.

13. A vulcanizable composition according to any one of claims 7 to 12, characterized in that they are based on the hydroxyl group-containing (H) NBR- autschuk either no or not more than 15 wt.% Solvent, preferably not more than 10 wt.% , particularly preferably not more than 5% by weight, very particularly preferably not more than 2% by weight and especially preferably not more than 1% by weight of solvent.

14. A vulcanizable composition according to any one of claims 7 to 13, characterized in that it is at least 33 wt.%, Preferably at least 35 wt.%, Particularly preferably at least 40 wt.% Of the hydroxyl group-containing (H) NBR rubber, based on contains the weight of the entire composition.

15. A process for the preparation of vulcanizable compositions according to any one of claims 7 to 14 by mixing at least one hydroxyl group-containing (H) NBR rubber and at least one crosslinker, as defined in any one of claims 1 to 4.

16. A process for the preparation of vulcanizates, characterized in that the vulcanizable composition is crosslinked according to one of claims 7 to 14 with heating.

17. Vulcanizates, preferably moldings, obtainable by the process according to claim 16.

18. Hydroxylgruppenhaltiger HNBR rubber, characterized by repeating units derived exclusively from (i) one or more conjugated dienes, (ii) one or more α, β-unsaturated nitriles and (ii) one or more copolymerizable ble hydroxyl-containing monomers each containing at least one hydroxyl group which is not bonded to the C atom of a carboxyl group to which an oxygen atom is further bonded by double bond.

19. A hydroxyl group-containing rubber according to claim 18, characterized in that the copolymerizable hydroxyl group-containing monomer (iii) is selected from the group consisting of hydroxyalkyl (meth) acrylates.