DE10120559A1 - A single stage process for mixing of nitrile rubber with fillers and/or additives useful in the automobile and oil industries significantly shortens mixing time without sacrifice of dispersion efficiency - Google Patents

Abstract

A single stage process for mixing of nitrile rubber with one or more fillers and/or additives comprises filling one or more nitrile rubbers into a kneader to 55-58% of its volume, kneading for 30-60 seconds, adding fillers and/or additives and continuing mixing for 40-180 seconds. Independent claims are included for: (1) a rubber mixture obtained as above; and (2) a crosslinkable rubber mixture containing this rubber mixture.

Description

The invention relates to a method for mixing nitrile rubbers, by the Rubber blends are obtained in which the additives are good in the Rubber matrix are dispersed.

To come from the raw rubber to usable end products, the Rubber / rubbers mixed with a wide variety of aggregates become. Due to the viscosity of the rubber are special for this purpose Mixing units, such as kneaders, rollers or mixers used. For a good ending product is a homogeneous dispersion of aggregates in the raw material rubber desirable. The quality of dispersion is often due to the dispersion expressed in terms of coefficients.

In order to achieve the highest possible production cycles, the industry lays on short Mixing times value, which, however, usually to poorer dispersion qualities to lead. Furthermore, multi-pass mixing sequences are performed wherever where a high proportion of fillers (eg soot, plasticizer etc.), more abrasive or very crystalline nature (eg silica, glass fiber etc.) or peroxide acceleration not agile. However, with increasing commercial pressure, input will be mixtures of these multisubstance mixtures, where this is technically feasible, substi tuieren.

A standard mixing procedure for a typical two-stage mixing sequence for an NBR or HNBR mixture is constructed as follows:

• 1. Mixing sequence in a kneader with intermeshing kneading blades:
  Temperature chamber / bucket: 25 ° C-50 ° C
  Stamp pressure: 8 bar
  Speed: 30 / min-50 / min
  Filling level: 58% -65%
  Mixing cycle kneader for more than 300 s and ejection of the finished mixture with a temperature above 140 ° C
• 2nd mixing sequence on a roller:
  Mixing cycle roller:
  • - Roll cooling variable depending on peroxide (between 40-80 ° C)
  • - Peroxide dosing on roller
  • - fur, incise 3 right, 3 left turns after doll forming
  • - Endfell formation

We have now found that a modified mixing process is significantly shorter Mixing times with comparable or even slightly better dispersion coefficients as allowed by standard mixing method. Furthermore, we found that the Addition of special fatty acids the dispersion end quality significantly and the Dispersion kinetics significantly improved, d. H. effective mixing time reduction by Addition of special dispersion additives causes. Furthermore, this mode allows fied mixing processes, peroxide cross-linked two-start mixing cycles on input to reduce mixing cycles. The 2nd mixing sequence (roll acceleration step) is no longer necessary for the inventive method of mixing; therefore, the procedure is one stage.

The subject of the application is thus a one-step process for mixing Nitrile rubber with one or more fillers and / or one or more Additives, characterized in that one or more nitrile rubbers in a kneader at a filling level in the range of 55-85% and presents for a Time in the range of 30-60 seconds kneads and then fillers and / or additives, and for a further period of time in the range of 40-180 Seconds mixes.

As kneaders are preferred kneader with tangent or interlocking Shovels in question.  

Preferably, the first period of time for kneading the rubber (s) is in the range from 30-59, especially 35-45 seconds. Preferably, the second period of time for mixing in the filler (s) and / or additives in the range of 40-179, especially 40-120 seconds.

Preferably, the mixture is carried out so that the ejection temperature of the finished mixture below 135 ° C, preferably below 130 ° C.

The degree of filling in tangential kneaders is preferably in the range of 75-80%, in intermeshing kneaders, preferably in the range of 65-70%.

In the process according to the invention, the chamber temperature and the blade temperature are advantageous in the range of 40-55 ° C, in particular in the range of 45-50 ° C.

The speed is advantageously in the range of 20-60 / min, in particular 35-40 / min.

The stamping pressure is advantageously in the range of 6.5-8.5 bar, in particular in Range of 7.0-8.0 bar.

By nitrile rubbers are meant diene (meth) acrylonitrile copolymers. Isoprene and especially butadiene are preferred dienes. The copoly merisate have a content of copolymerized acrylonitrile and / or methacrylic nitrile units of 5 to 60, preferably 10 to 50 wt .-%.

Furthermore, hydrogenated nitrile rubbers are expressly termed sub summed. The term "hydrogenated nitrile rubber" or "HNBR" is intended to refer to this Invention nitrile rubbers whose C = C double bonds selectively (i.e., without Hydrogenation of the C~N triple bond) are partially or fully hydrogenated, be understood. Preferred hydrogenated nitrile rubbers are those having a Degree of hydrogenation, based on the butadiene-derived C = C double bonds,  of at least 75, preferably of at least 95, in particular of at least 98%. The degree of hydrogenation can be determined by NMR and IR spectroscopy.

The hydrogenation of nitrile rubber is known from US-A-3 700 637, DE-A- 25 39 132, DE-A-30 46 008, DE-A-30 46 251, DE-A-32 27 650, DE-A-33 29 974, EP-A-111 412 and FR-B-2 540 503, the said documents being hereby incorporated by reference For purposes of United States patent practice as a reference in the present application be taken. Hydrogenated nitrile rubber is characterized by high tear strength, low abrasion, low deformation after compression and tension and good oil resistance, but above all by remarkable stability against thermal and oxidative influences. Therefore, hydrogenated nitrile rubbers in Framework of the invention preferred.

Suitable nitrile rubbers generally have Mooney viscosities (DIN 53 523, US Pat. ML 1 + 4) from 25 to 100 ME, in particular 40 to 80 ME.

Particularly suitable are nitrile rubbers with a content of residual emulsifiers of less than 1% by weight

Residual emulsifiers are u. a. Fatty acids, among which the expert organic acids usually in the range of 8-22 carbon atoms, especially 14-18 Carbon atoms understands. These fatty acids are from the manufacturing process the nitrile rubbers and cause processing problems v. a. in injection molding procedures in which they lead to mold contamination.

The filler used / the fillers used can be unreinforcing or ver to be empowering.

Examples of fillers which may be mentioned are:

• Carbon blacks, such as MT, GPF, SRF and especially FEF blacks,
• Metal oxides, such as titanium dioxide (especially as white pigment),  
• - silicates, such as sodium aluminum silicate,
• - silicic acids, in particular precipitated silicas,
• - Clays, mica, talc.

In order to improve the abrasion, so-called active fillers are preferably suitable in accordance with the proposal ISO 5794, Annex D part 1, z. B. published z. B. on P. 535 of the "Handbook for the Rubber Industry" of Bayer AG, 1992, Leverkusen.

Examples of additives are the vulcanization activators known to the person skilled in the art, in particular metal oxides, such as zinc oxide or magnesium oxide; Antidegradants, such as alkyl-substituted diphenylamines, mercaptobenzimidazoles; unsaturated ethers, such as Vulkazon® AFD (Bayer AG, D) or cyclic, unsaturated acetals, such as Vulkazon® AFS / LG (Bayer AG, D) in question. Furthermore, as additives are mentioned:

• - Plasticizers, in particular carboxylic acid esters, such as sebacic acid and their Derivatives or trimellitic acid and its derivatives,
• - Polymer processing aids, such as poly-ethylenevinylacetate (Levapren® Bayer AG, D) or poly-ethylenevinyl acrylate / VAMAC® from DuPont),
• - Dispersion or lubricant, in particular zinc soaps, such as. B. under the Trade names Aktiplast® T, Aktiplast® T60, Aktiplast® PP, Aktiplast® ST, Aktiplast® GT or GT / M from Rhein Chemie Rheinau GmbH, Germany, as well as blends of fatty acid mixtures and esters alcohols, such as. B. commercially available under the trade names Aflux® 12, Aflux® 25, Aflux® 16, Aflux® 42 or 42M and Aflux 54® from Rhein Chemie Rheinau GmbH, Germany.

In addition, it may be advantageous to use additional activators for adhesion use improvement between filler and rubber, such as. B. silanes, such as Ucarsil® RC-1 (Union Carbide, US). Furthermore, pigments can be added.  

The amounts of the individual components of the mixture depend on the one purpose of the mixture and can be determined by a few preliminary tests.

As a rule, the substances are used in the following quantities (in each case in phr = per hundred parts of rubber):

• - anti-aging agents in the range of 0 to 4 phr,
• - Retarder in the range of 0 to 2 phr,
• Metal oxides, such as ZnO in the range of 0 to 10 phr,
• Fillers in the range from 0 to 150 phr, preferably active fillers,
• Plasticizer in the range of 0 to 50 phr,
• - Dispersion lubricant in the range of 0.1 to 4 phr.

Particularly advantageous in the inventive mixing method, the addition of Dispersion additives, the salts of fatty acids with at least 16 carbon atoms are proven. Preferred are salts of fatty acids with more than 18 carbon atoms atoms. Native fatty acid salts, such as the salts of rapeseed oil, the soybean oil fatty acid, the fish oil fatty acid or mixtures of these components if with other fatty acids, proved to be particularly advantageous.

The calcium, magnesium, barium, strontium and zinc salts are preferred of fatty acids, especially zinc salts. Especially suitable zinc salts are Zn Soaps of rapeseed oil fatty acid (under the trade name Aktiplast® T or Aktiplast® T60, Rhein Chemie Rheinau, Germany) and that are Zn soaps of a fat acid / paraffin (Aflux® 25 from Rhein Chemie Rheinau, Germany).

The salts of said fatty acid significantly improve dispersible quality and are preferably used in HNBR in amounts in the range of 0.1-2 phr; more preferably 0.5 phr are used. At NBR, quantities are in the Range of 0.1-4 phr used; 1-3 phr are particularly preferably used.  

It may be advantageous to place these dispersion additives on a carrier substance used to insert.

Also suitable as dispersion additives are the commercially available dispersants anionic additives from Schill & Seilacher, Germany, Struktol® WB215, Struktol® WB42, Struktol® A60, Struktol® WA 48, Struktol® EF 44, Struktol® FL; the Dispersion additives from DOG Germany, Dispergum® N, Dipergum® T, Deoflow® A, Deoflow® D, Deogum® 80, Deosol® H. Furthermore, these are the Dispersion additives from Kettlitz, Germany FL, KB, OX; Technical Processing USA TE 28 E, TE 28-G9, TE-28-G10, TE 70, TE 75, TE 80, TE 88 XL; the Fa. Vanderbilt, USA Bendogen®, K-Stay® G, Leegen®, Vanfre® AP-2, Vanfre® DFL, Vanfre® HYP, Vanfre® IL-2, Vanfre® UN, Vanfre® M. Furthermore, these are the Dispersion additives from Great Lakes, Italy Polyplastol® 4, Polyplastol® 15, Polyplastol® 17, as well as the company Kawaguchi, Japan Exton® L-2, Exton® L-7.

Due to the shorter mixing time, the rubbers available in the process are Mixtures less degraded. Therefore, these rubber compounds make a Another object of the invention.

To prepare crosslinkable mixtures of the mixtures according to the invention, In addition, crosslinkers are added to the rubber mixtures. These networked mixtures are another subject of the application. As Ver The latter are suitable peroxide systems, sulfur and / or sulfur donor systems.

Preferred peroxide systems include:
dialkyl
ketal peroxides,
aralkyl,
Peroxidether,
Peroxide esters, such as. B.
Di-tert-butyl peroxide,
Bis (tert-butylperoxyisopropyl) benzene,
dicumyl peroxide,
2,5-dimethyl-2,5-di (tert-butylperoxy) hexane,
2,5-dimethyl-2,5-di (tert-butylperoxy) -hexen- (3),
1,1-bis (tert-butylperoxy) -3,3,5-trimethyl-cyclohexane,
benzoyl peroxide,
tert-butyl cumyl peroxide and
tert-butyl perbenzoate.

The amounts of peroxide are in the range of 1 to 10 phr, preferably in the range from 4 to 8 phr, based on rubber. The crosslinking can take place at temperatures of 100 to 200 ° C, preferably 130 to 180 ° C, optionally under a pressure of 10 to 200 bar, done. Following the crosslinking, the vulcanizates be tempered by storage at elevated temperature.

The peroxides can advantageously also be used in polymer-bound form become. Corresponding systems are commercially available, such as Polydispersion T (VC) D-40 P from Rhein Chemie Rheinau GmbH, D (= poly mer bonded di-tert-butyl peroxy-isopropylbenzene).

Further suitable crosslinkers are sulfur or sulfur donors and combi nations from these components.

Sulfur can be as soluble or insoluble sulfur, as a mixture thereof (powdered, coated) or used in other suitable form, for. B. as premixed mixture of sulfur and rubber "sulfur". The dose tion is usually in the range of 0.1 to 5 phr, preferably 0.1 to 1.5 phr.

As sulfur donors are usually derivatives of thiuram in question, esp especially tetramethylthiuram disulfide, tetraethylthiuram disulfide, tetrabutylthiuram disulfide and tetrabenzylthiuram disulfide. These in turn can be combined  used with other sulfur-containing components, for Example dithiomorpholide dithiocaprolactam or other compounds with di-, tri-, tetra- or poly-sulfide structure.

The dosage of the thiuram derivatives is usually in the range of 0.5 to 5 phr, preferably 1 to 2.5 phr. The dosage of the supplemental, sulphurous com components is usually in the range of 0.1 to 3 phr, preferably 0.5 to 1.5 phr, to choose.

Sulfur crosslinking systems may also contain accelerators. In question are preferably accelerators of the mercaptobenzothiazole or mer type capto-benzothiazyl disulfide with dosages usually in the range of 0.5 to 3 phr, preferably 0.5 to 1.5 phr or so-called sulfenamides, such as Cyclohexyl benzo-thiazyl sulfenamide (CBS), tert-butyl benzothiazyl sulfenamide (TBBS), morpholine benzothiazyl sulfenamide (MBS), dibenzylbenzothiazyl sulfen amide (DCBS), these usually in dosages in the range of 0.5 to 3, preferably 0.5 to 1.5 phr, are used.

Furthermore, it may be advantageous to use the following additives:

• Zinc salts of dithiocarbamic acids in dosages in the range of 0.5 up to 1.5 phr,
• - Derivatives of dithiophosphoric acid, guanidines and others in the rubber industry standard, aminic accelerators,
• Retarders, such as phthalic acid, phthalic anhydride, benzoic acid or Salicylic acid or other organic acids, such as N-nitroso-verbin such as N-cyclohexylthiophthalimide or other sulfonamide Derivatives such as Vulkalent E / C of Bayer AG.

The crosslinking can also be achieved by high-energy radiation.  

Crosslinking in the sense of the invention means that extraction at 10 hours in the Soxhlet attachment with toluene as extractant less than 10, preferably Less than 5 wt .-%, based on rubber, extractable.

The optimal amount of crosslinker is easily determined by preliminary experiments. It is hereby known that the amount of necessary peroxide is indirectly proportional to Residual double bond content of the rubber is.

As a mixing element for the preparation of crosslinkable mixtures of the Invention mixtures according to any known to the expert mixing element for Rubbers are used, in particular kneaders, rollers and screws.

It is important to ensure that the rubber does not during the mixing process is reduced. It may be advantageous to cool during the mixing process. Around To avoid scorch, the crosslinker is often given as the last component if in a separate mixing, added.

The inventive method can be in an advantageous manner output produce mixtures for a variety of moldings.

Especially used in the automotive industry moldings are used in the following areas of application:

• - drive belts, tooth, polymer belts,
• - Seals / diaphragms, in various designs O-rings, U-rings,
• - fuel-carrying components (hoses),
• - air components (hoses),
• - oil-carrying components (hoses),
• - water-carrying components (hoses),
• - heating / air conditioning / ventilation (hoses),
• - Electrical, cable sheathing (hoses),  
• - spark plug,
• - cuffs / dust caps,
• - clutch disc pads,
• - valve cover,
• - sound insulation,
• - Fans, frames and tension rollers.

Especially used in the production of oil, moldings of the invention are:

• - gaskets of various designs on drill pipes, Hanging and pipes, such. B. O-rings and U-rings, individually or as packs,
• - Packer seals u. ä.,
• - Adjustment elements, spacers, protectors and elastic bearings (also inflatable) for drill pipes, hangers, pipes and aggre gate,
• - seals and inserts for blow-out preventers,
• - Seals, diaphragms and balls for control valves and the like institutions
• - Seals, diaphragms and bubbles for pulse dampers u. ä.,
• - sealing plug,
• - Seals, diaphragms, rotors (impellers) and stators of Pump,
• - plugs and seals for pipe cleaning,
• - Reinforced and unreinforced hoses, swim hoses,
• - Cable insulation and sheaths.

For a person skilled in the art, it is trivial to add the mixtures according to the invention by adding Other polymers such as BR, NR, IIR, IR, EPDM, EPM, CR, SBR, AEM, ACM or Fluoropolymers, to tailor their properties exactly.  

The following examples serve to illustrate the invention without restricting it want.  

Examples feedstocks

Therban® A 3406 is an HNBR with 34% acrylonitrile content, a Mooney value of 68 ME and a maximum of 0.9% residual double bond content of Bayer AG, Germany. Perbunan® NT 2845 is a NBR with 28% acrylonitrile content, a Mooney value of 45 ME from Bayer AG, Germany.

measurement methods

example 1

The mixtures listed in Table 1 were prepared, in each case the Formulation ingredients are given on 100 parts of rubber.

Table 1

The standard two-speed mixing production for M1 (also as standard or stand. denoted) was carried out in a commercially available laboratory kneader GK 1.5 E (Krupp, Elastomer Technology, Hamburg), cooling water temperature 50 ° C, blade speed 40 rpm, punch pressure 8 bar, kneading degree 68%, based on the chamber volume of the kneader.

The kneader diagram of the kneading mixing process of the two-stage standard mixing process is shown in Fig. 1 (Kneader Mix M1 / Standard). The polymer is premixed for <60 s, after which the stamp is opened, which is demonstrated by the stamping position shown in FIG .

Then fillers, carbon black and plasticizer are added. Subsequently, will the kneader is closed and the carbon black dispersion (BIT = Black Incorporation Time; is signaled by decreasing conductivity) starts. After <120 s mixing time the kneader is opened again to degas the mixture and the rest Fillers remaining in the punch chute are swept into the mix. After that is <60 s ready mixed.

The emptying of the kneader was carried out at a batch temperature of <125 ° C. The Peroxide was on a rolling mill (Krupp, Elastomer technology) at 40 ° C. Cooling water temperature mixed.

In Fig. 2-4, the kneader diagrams of the inventive mixing method are listed.

Figure 2 Input Mixer Merging Procedure for M2 (also referred to as 30/40).

The polymer is premixed for 30 seconds; then the dosage of the fillers, Plasticizers, chemicals, dispersing additives as well as peroxide accelerators.

After 40 seconds and at 100 ° C batch temperature, the mixture was ejected. to closing the mixture was pulled out by a roller gear to the coat.

Fig. 3 shows the input mixing procedure for M3 (also referred to as 30/80). The polymer is premixed for 30 seconds; then the dosage of fillers, plasticizers, chemicals, dispersing additives and peroxide accelerator takes place.

After 80 seconds and at 130 ° C batch temperature, the mixture was ejected. to closing the mixture was pulled out by a roller gear to the coat.  

Fig. 4 shows the input mixing procedure for M4 (also referred to as 30/120). The polymer is premixed for 30 seconds, followed by metering of fillers, plasticizers, chemicals, dispersing additives and peroxide accelerators. After 120 seconds and at 138 ° C batch temperature, the mixture was ejected. At closing the mixture was pulled out by a roller gear to the coat.

The plates for the determination of the mechanical properties as well as the determination of the dispersion by the Dispergrator method were vulcanized in a vulcanizing sier press (Krupp, Elastomer technology) at 180 ° C to t ₉₀ + 5 minutes.

Dispersion measurements of the mixture or vulcanizates M1-M4

FIG. 5 shows the soot dispersion quality in a value scale from 10 (optimal) to 1 (undispersed). The two-stroke mixing rule is referred to herein as standard and has been applied to mixture M1.

The mixer mixing time of this standard mixing instruction equals 240 s excluding the 3-5 min. Mixing time on the rolling mill. By adding the dispersant Aktiplast® T or Aflux® 25 increases the dispersion quality of vulcanizates M1 0.8 points when using the standard mixing rule.

After a total mixing time of 30 + 80 = 110 s with the inventive Mischvor The result is the same dispersion quality as with standard mixing instructions mixed series. Furthermore, the addition of 0.6 phr of dispersion additive causes much faster setting of a better dispersion quality. After 70 s of mixing time is already achieved a dispersion quality of 4.8-5.0 points.

FIG. 6 shows the number of soot agglomerates <23 μm still detectable for the optical disperser method.

The scale of values 10-1 means: no detectable agglomerates at 10 and very many agglomerates at value 1. High agglomerate number means low Agglo meratanzahl. Again, the mixing time shortening effect of the new mix as well as the dispersion kinetics effect of the dispersion additive.

Dynamic measuring method for the determination of soot dispersion

Fig. 7 shows the curve of the storage modulus of the uncrosslinked batches M1-M4 again. A lower storage modulus G 'of uncrosslinked rubber mixtures with low deformation amplitude (10%) and constant measurement temperature (100 ° C.) correlates with better dispersion of carbon black.

Again, the mixing time-shortening effect of the new blending regulation is as well the dispersion kinetics effect of the dispersion additive can be seen.

Influence of dispersing additives on processability / rheology

An additional positive effect of the dosage of 0.6 phr dispersing additives is the lowering of the mixture viscosity by about 10-15 ML points. This means an improved processability of the rubber batt as well as a better flowability, which is expressed in the injection molding simulation, the Rheovulkametermethode. This is demonstrated in Figs. 8-9.

Fig. 8 Mooney viscosity of the mixture,

Fig. 9 Füllgradbeeinflussung the injection mold.

The typical results of the physical tests are shown in Table 2 given. Based on the physical values, a two-way mixing rule is as in M1 practiced with an input mixing rule as applied to M3 comparable.  

Table 2

Example 2

The mixtures listed in Table 3 were prepared, in each case the Formulation ingredients are given on 100 parts of rubber.

Table 3

These mixtures were prepared analogously to Example 1 in a laboratory kneader GK 1,5 E (eben if Fa. Krupp, Elastomer Technology). Analogously to Example 1 were at the Mix M5 mixed with a 2-stage process (kneader cooling water temperature 50 ° C, vane speed 50 rpm, ram pressure 8 bar, kneading degree 65%, based on the chamber volume of the kneader; then the accelerators were on added to the roller). Total mixing time of the mixture M5 in the kneader corresponds 240 s.

M6 mixture and mixtures M7, on the other hand (variable factor is the dispersant medium) were prepared with the mixing method according to the invention.

Submit polymer 30 s Remaining ingredients 60 s, 90 s and 150 s respectively AL = L <fur on roller

Kneader settings were: Cooling water temperature 40 ° C, blade speed 50 rpm, Stamp pressure 8 bar, kneading degree 68%, based on the chamber volume of the Kneader.

The different mixing time combinations are indicated by the term 30/60, 30/90 and 30/150.

Fig. 10 Optical dispersion of NBR vulcanizates.

As can be seen from FIG. 10, the dispersion of the standard two-step mixing method (M5, only total mixing time of kneader 240 s without roll acceleration 3 min) is 8.0 on the dispersion value scale. Mixture M6, which was mixed with the inventive mixing method, achieved after 180 s total mixing time without roll acceleration a dispersion value of 7.8 points, which represents no significant difference to M5 within the measurement accuracy.

Furthermore, it can be seen that by adding 3 parts of dispersant Aflux® 42 and Aflux® 25 have a dispersion quality of 8.0 value points after one Total mixing time of 30 + 120 = 150 s can be achieved. Thus, the mixing time ver shortening effect of the inventive mixing rule as well as the dispersion kinetikeffekt this specially suitable for NBR dispersion additive.

The typical results of the physical tests are shown in Table 4 given. Based on the physical values, a two-way mixing rule is as in M5 practiced, with an input mixing specification, as with M6 or M7 (30/150) applied, almost comparable.

Table 4

Influence of dispersing additives on processability / rheology

An additional positive effect of the dosage of 0.1-4 phr dispersing additives, more preferably 0.5-3 phr, is the lowering of the mixture viscosity by approx. 5-10 ML points. This means an improved processability of the rubber batches as well as a better flowability, what in the injection molding simulation, the Rheovulka as well as in laboratory extruder experiments as a simulation for rubber extrusion is expressed.  

Table 5

Claims (10)

1. A single-stage process for mixing nitrile rubber with one or more fillers and / or one or more additives, characterized in that one or more nitrile rubbers in a kneader at a degree of filling in the range of 55-85% presents and for a period of time in the Kneads range of 30-60 seconds and then adding fillers and / or additives and mixed for a further period in the range of 40-180 seconds. 2. The method according to claim 1, characterized in that the / the nitrile Rubbers are selected from the group NBR, partially hydrogenated NBR and fully hydrogenated NBR or mixtures of two or more of the groups composed of links. 3. The method according to claim 1 or 2, characterized in that the Contains additive dispersion additives. 4. The method according to claim 3, characterized in that the dispersion additives are selected from the group fatty acid esters, fatty acid Paraffin blends, salts of a fatty acid or mixtures of two or several of these compounds 5. The method according to claim 3 or 4, characterized in that the fat acid is a fatty acid having 16 or 18 carbon atoms or greater or less Mixture of these is. 6. The method according to any one of claims 1 to 5, characterized in that the mixture further contains a siliceous filler, carbon black, zinc oxide, magne or a mixture of two or more of these components.   7. The method according to any one of claims 1 to 6, characterized in that the mixture vulcanization retarder and / or Vulkanisationsbeschleu contains niger. 8. rubber mixture, obtainable in a process according to one of the An Proverbs 1-7. 9. Crosslinkable rubber mixture, comprising a rubber mixture according to Claim 8. 10. Use of the rubber mixture according to claim 8 or 9 for Her Position of moldings of all kinds.