EMISSIONSARME, NITRILKAUTSCHUKE ENTHALTENDE PULVERFÖRMIGE MISCHUNGEN

Low-emission, nitrile-containing powdery mixtures

The present invention relates to low-emission powdery mixtures comprising at least a specific nitrile rubber and one or more release agents, their preparation and their use for the production of composites containing additionally at least one

Thermoplastics and based on these materials, particularly components for indoor applications.

Powdered nitrile rubbers are used in diverse applications. They are, for example, in the modification of phenolic resins in the manufacture of brake components, -belägen or -

used discs. Furthermore, they are used to modify thermoplastics, in particular for the modification of polyvinyl chloride (PVC) because of the excellent compatibility with this widely used plastic. Such elasticized PVCs are used for example for the production of profiles, cable sheaths or gaskets. Several of these components are used in the automotive sector. Accordingly, potential applications of these components can also be found inside the vehicle, especially in interiors of motor vehicles, or, if not in the automotive sector, for. As in building interiors. In this regard, the provision of powdery rubbers with low emissions increasing importance is because were reinforced laid down new rules and regulations to reduce emissions in recent years. Therefore, the reduction and control of emissions from plastic parts as well as rubber and thus also of elasticized thermoplastics is a particular requirement.

In principle, a number of rubbers are also conceivable for the production of elastomers in powder form, such as NBR, EPDM or SBR. However, especially when a modification of

desired, PVC, polyurethanes or polyamides (for example, to increase the impact strength) are particularly useful because of the excellent compatibility nitrile rubbers. The use of rubber powders allows here a better dosage and to disperse in thermoplastics and thus a more homogeneous properties.

The American Indoor AirPlus list recommended especially for indoor applications the use of low-emission materials.

ISO 12219-1: 2012 describes the test procedure and the determination of VOCs (volatile organic compounds) in the interior of automobiles. Three different tests are described in the ISO standard, in which two relates to the determination of the volatile VOCs in the car interior, and to the determination of formaldehyde. An example of the use of low-emission polymeric materials found in CN 102757597, in which particularly low odor polypropylene (PP) is described which is modified with elastomeric materials. The material described is characterized by low odor, as well as good mechanical properties. The low odor is achieved by adding a deodorant, so an odor absorbing agent. Particularly suitable such materials for use in vehicle interiors have been. A particular form of working up, or in which the polymers used will be used does not mention the mold.

In the application CN 1730544 fabricating a component using an ABS resin is described, which is characterized by reduced odor. Here, in addition to the

Terpolymer blended during the compounding of a "odor suppressing" substance. The substance is an alkali metal aluminum silicate powder, or a combination thereof with silica gel. Thus, the substances responsible for the odor remain in the polymer in place and are only by way of odor bound materials. A particular form of working up, or in which the polymers used will be used does not mention the mold.

In CN 102617940 production of the mixture of different elastomers, including NBR, is described with typical additives. The resulting gum is characterized by good insulation properties and to be suitable for use in the automotive sector. There is no reference to a method of reducing somehow gearteter emissions.

The use of mercaptans as molecular weight regulator in the polymerization for the production of copolymers or terpolymers is described in JP 50023713th These terpolymers containing, inter alia acrylonitrile and butadiene as monomer units. After carrying out the polymerization of the latex is treated with peroxide or peracetic and thus achieves a reduction in odor of the polymer. A disadvantage of this process is that the polymer contained in the latex may have reacted with the peroxide or peroxyacetic acid and leads to the formation of undesirable by-products or a pre-crosslinking.

In an as yet unpublished European patent application to provide nitrile rubbers with a very good cure behavior and a simultaneously improved emission behavior is described, the corresponding vulcanizates have excellent properties. this nitrile rubbers are characterized by repeating units of at least one α, β-unsaturated nitrile monomer and at least one conjugated diene monomer by an emission quotient E of the formula (I) of less than or equal to 0.25 mg / (kg * Mooney units), [ volatiles] [nitrile]

E = ^x (I)

[Mooney viscosity] 100

wherein

[Volatiles] is the concentration of volatile components in mg / kg nitrile rubber, by a TDS-GC / MS analysis according to VDA 278 Recommendation (version 09/2002) between 28.4 min and 34.0 min are determined,

[Mooney viscosity] the ASTM D 1646 specific Mooney viscosity ML 1 + 4 at

100 ° C of the nitrile rubber specified in Mooney units represents, and

[Nitrile] dimensionless the specified content of the α, β-unsaturated nitrile in

Nitrile rubber is determined in wt.% According to DIN 53 625 by the Kjeldahl method.

Buy this nitrile rubbers, when the emulsion polymerization carried out under the choice of particular molecular weight regulator and simultaneously the polymerization up to a conversion of 60% or higher is performed. Also disclosed are curable mixtures based on the emission nitrile rubber and its general suitability for belts, roll coverings, seals, caps, plugs, tubes, coverings, sealing mats or - sheets, profiles or membranes. Whether and in what spatial shape apply the low-emission and rubbers are used to prepare the corresponding mold parts, no consideration is given. Typical of the applications mentioned there is the application form of the rubber bale and the rubber crumbs. On the properties of powdery NBR is not discussed.

Nitrile abbreviated, also referred to as "NBR", rubbers to be understood, where it is co- or terpolymers of at least one α, β-unsaturated nitrile, at least one conjugated diene and optionally one or more further copolymerizable monomers. Such nitrile rubbers and processes for producing such nitrile rubbers are known, see for example Ullmann's Encyclopedia of Industrial Chemistry, VCH, Weinheim, 1993, pp 255-261.

NBR is typically prepared by emulsion polymerization, which firstly gives an NBR latex. The NBR solid is isolated from this latex by coagulation, usually with the use of salts or acids. The solid rubbers thus obtained can be converted by grinding in pulverulent elastomers. In an alternate workup, the NBR powder is directly recovered from the latex by spray drying. The emulsion polymerization must be carried out using molecular weight regulators customarily to obtain polymers with good processing properties. Molecular weight regulators commonly used are based on mercaptans. acrylic acid for the molecular weight control of emulsion rubbers based monomers such as styrene, butadiene, acrylonitrile, (meth), fumaric acid, ethyl acrylate, butyl acrylate, 2-ethylhexyl acrylate, chloroprene, and the other is in particular the use of Dodecylmercaptanen important.

In US-A-2,434,536 describes that synthetic rubbers based on diolefins such as butadiene and optionally other copolymerizable monomers such as styrene, a- methylstyrene, vinylnaphthalene, acrylonitrile, methacrylonitrile, methyl methacrylate, ethyl fumarate, or

Methyl vinyl ketone is prepared by emulsion polymerization in the presence of aliphatic mercaptans as molecular weight regulators. Disclosed is that these mercaptans have at least 7 and preferably 10 or more carbon atoms. aliphatic mercaptans are preferably used with an average molecular weight 188-230 which is at least 50% dodecylmercaptan and the remaining portion to 100% in the form of mercaptans having 10 to 16

comprise carbon atoms.

Nitrile rubbers are described in EP-A-0692496, EP-A-0779301 and EP-A-0779300 each described on the basis of an unsaturated nitrile and a conjugated diene, which have in common that they contain 10-60.% having viscosity in the range 15-150 or, according to EP-a-0692496> unsaturated nitrile and a Mooney of 15-65 and all have at least 0.03 mol of C12-C16-alkylthio group per 100 mol monomer units comprise said alkylthio group includes at least three tertiary carbon atoms and a sulfur atom which is directly bonded to at least one of the tertiary carbon atoms. The production of the nitrile rubbers are in each case in the presence of a correspondingly constructed Ci2-Ci6-alkyl thiol as a molecular weight regulator, which acts as a "chain transfer agent", and is thus incorporated as end group into the polymer chains. Measures by which an influence of the VOC values ​​of the nitrile rubber or nitrile - rubber-containing powder and the profile of properties of composites based on it or moldings are possible, the teaching of this patent can not be removed.

In Ullmanns Enzyklopadie der technischen Chemie, 4th Edition, Volume 13, pp 611-612 is described in general, that the molecular weight of nitrile-butadiene rubbers can be controlled by the use of alkyl mercaptans, di- and polysulfides or xanthogen disulphides. tert-dodecyl mercaptan, and Diisopropylxanthogendisulfide be mentioned as mainly used controller. Even in industrial practice often tertiary Docdecyl- be used mercaptans (also called "TDM" or "TDDM" for short). is known for example that commercially available from Chevron Phillips DM, which is typically of a large mixture verschiedenster isomers. Our own studies have shown that are prepared using tertiary dodecyl nitrile rubbers, in VOC tests (carried out by TDS GC / MS studies according to VDA 278 recommendation) have a high content of sulfur compounds and also non-sulfur-containing impurities of the TDMs, which in can be perceived some practical applications, especially indoors and perform unpleasant odors.

While there is about the influence of different usable for coagulation of salts on the properties of the nitrile rubber obtained extensive literature, there are no signs or studies on the influence of the molecular weight regulator to the VOC values ​​of nitrile rubbers. For special applications indoors such. However, as in the construction sector or in the vehicle interior based on nitrile rubbers, the VOC values ​​is of considerable importance. This applies both to the use of NBR as the solid rubber and the use of NBR in powder form. In summary, it should be noted that until now no measures yet have become known as one can get with the use of mercaptans as molecular weight regulators nitrile rubbers and containing these powdered mixtures with a significantly reduced VOC content, which can be used for the production of such components indoors for which the use of powder mixtures is advantageous.

In general, claims the industry have risen rubbers with low emissions, especially for indoor applications such as passenger compartments of automobiles. In the production of nitrile rubber-based powder types by grinding or spray drying already a reduction of the volatile components can be obtained, the starting rubbers contain relatively high proportions of volatile components. These are given in the preparation of the powder in the production environment and thus increase the burden on people and the environment in the production area. To minimize this loading, the components of the polymerization recipe are to be selected so that already thereby a reduction of the VOC values ​​is made possible. The object of the present invention is to provide nitrile rubbers containing powder mixtures, which are suitable for the manufacture of components that can be used indoors and the significantly lower emissions than hitherto known nitrile rubber powder. The present invention is thus a powdery mixture containing

and comprises (1) at least one nitrile rubber, of the repeating units of at least one α, β- unsaturated nitrile monomer and at least one conjugated diene monomers an emission quotient E of the formula (I) of less than or equal to 0.25 mg / (kg * Mooney units) has,

[Volatiles] [Ni tri Ig ehalt]

E = x (I)

[Mooney viscosity] 100

wherein

[Volatiles] is the concentration of volatile components in mg / kg

Nitrile represents, by a TDS-GC / MS analysis according to VDA 278 Recommendation (version 09/2002) min between 28.4 and 34.0 min are determined,

[Mooney viscosity] the ASTM D 1646 specific Mooney viscosity ML 1 + 4 at

100 ° C of the nitrile rubber specified in Mooney units represents, and

[Nitrile] dimensionless the specified content of the α, β-unsaturated nitrile in

Nitrile rubber is determined in wt.% According to DIN 53 625 by the Kjeldahl method,

and

(2) one or more release agents,

characterized in that the powdery mixture of (1) and (2) has an average particle diameter D _{a is} in the range of 0.01 to 4 mm. The invention furthermore relates to the preparation of low-emission powdery mixtures of the invention as well as their use for the production of composites, containing in addition at least one thermoplastic, these composite and based thereon components. Average particle diameter of the powdery mixtures:

The average particle diameter D _a of the powdery mixture is granulometrically determined by weighing 2.0 mm 100 g of the powdered mixture in a sieve with a mesh size below this first screen more sieves with the mesh size 1.4; 1.0; 0.8; clamps 0.6 and 0.3 mm in place, the composite wires on a vibratory screening machine (for example, AS 200 control, g ', Fa. Retsch), and then moves at an amplitude of 2.00 mm for a period of 30 min, the content auswiegt each screen and the mean particle diameter D _A of the formula (1) is calculated

wherein

D _{a is} the average particle diameter in mm, X; . The wt% - means the proportion retained in each sieve mass of the powdery mixture in g

D; n is the average mesh size of the screen and each n + 1 denotes in mm, which results from the following formula (2) gives

Di = (D _n + D _{(n + 1))} / 2 (2) wherein

D _n of the mesh diameter of the sieve n in mm, and

D _{(n + i)} s of the mesh diameter of the screen + 1 is in mm. The average particle diameter of the powdery mixtures of the invention can influence within the above mentioned limits of 0.01 to 4 mm to some extent by the nature of the preparation, as described below:

In one embodiment, the powdery mixture have an average particle diameter D _{a is} in the range of 0.01 to 4 mm, preferably in the range of 0.05 to 3 mm, particularly preferably in the range of 0.1 mm to 2 mm and particularly preferably in the range from 0.2 mm to 1.5 mm. These powdery mixtures are obtainable, for example, when the nitrile rubbers (1) are used which are obtainable by grinding. In another embodiment, the powdery mixture have an average particle diameter D in _a range of 0.01 to 2 mm, preferably in the range of 0.04 mm to 1 mm, particularly preferably in the range of 0.06 to 0.75 mm and particularly preferably in the range of 0.08 mm to 0.12 mm. These powdery mixtures are obtainable, for example, when the nitrile rubbers (1) are used which are obtainable by spray-drying.

For both embodiments, the implementation is described below in the preparation of the powdery mixtures.

NBR:

The nitrile rubber present in the inventive powder mixtures having an emission quotient E of the general formula (I) of less than or equal to 0.25 mg / (kg * Mooney units), preferably less than or equal to 0.22 mg / (kg * Mooney units) and particularly preferably less than or equal to 0.20 mg / (kg * Mooney units). The volatile constituents, the concentration by TDS-GC / MS analysis according to VDA 278 Recommendation (version 09/2002) between 28.4 min and 34.0 min are determined in order to calculate the emission coefficient, there are typically volatile components of the molecular weight regulator used , The determination of the Mooney viscosity of the nitrile rubber (ML 1 + 4 at 100 ° C) according to ASTM D 1646 is typically carried out using non-calendered nitrile rubbers according to the invention.

The present invention employed the nitrile rubbers have repeating units of at least one α, β-unsaturated nitrile and at least one conjugated diene. Optionally, it may also repeating units of one or more other copolymerizable monomers contained is essential that the emission quotient E of the general formula (I) of less than or equal to 0:25 mg / (kg Mu) is satisfied.

The repeating units in the nitrile rubber, at least based on a conjugated diene go, preferably (C4-C6) conjugated dienes back. Particularly preferably 1,2-butadiene, 1,3-butadiene, isoprene, 2,3-dimethylbutadiene, piperylene or mixtures thereof. Particularly preferred 1,3-butadiene and isoprene or mixtures thereof. Most particularly preferred is 1,3-butadiene.

As α, β-unsaturated nitrile may be used any known α, β-unsaturated nitrile for the production of the nitrile rubbers according to the invention, _(C3-C5) are preferably -a, ß-unsaturated nitriles such as acrylonitrile, methacrylonitrile, ethacrylonitrile or mixtures thereof. Acrylonitrile is particularly preferred.

In one embodiment of the invention the powder mixture containing a nitrile rubber containing repeating units of acrylonitrile and butadiene, particularly preferably having repeating units of only acrylonitrile and butadiene.

As other copolymerizable monomers, for example, aromatic vinyl monomers, preferably styrene, α-methyl styrene and vinyl pyridine, may be used as well as non-conjugated dienes such as 4-cyanocyclohexene and 4-vinylcyclohexene, or alkynes such as 1 - or 2-butyne.

Further, epoxy group-containing monomers can be used as a copolymerizable termonomers, preferably glycidyl acrylate and glycidyl methacrylate.

Alternatively copolymerizable termonomers, for example, α, β-unsaturated monocarboxylic acids, esters thereof, α, β-unsaturated dicarboxylic acids, their mono- or diesters, or their corresponding anhydrides or amides as a further carboxyl group-containing copolymerizable monomers are used. As α, β-unsaturated monocarboxylic acids are preferably acrylic acid and methacrylic can also be used.

Also employable are esters of α, β-unsaturated monocarboxylic acids, preferably their alkyl esters and alkoxyalkyl esters. the alkyl esters, in particular CpCig alkyl esters of α, β-unsaturated monocarboxylic acids, particularly preferred are alkyl esters, in particular Cp CI8 alkyl esters of acrylic acid or methacrylic acid, especially methyl acrylate, ethyl acrylate, propyl acrylate, n-butyl acrylate, tert-butyl acrylate, 2-ethylhexyl acrylate are preferred , n-dodecyl acrylate, methyl methacrylate, ethyl methacrylates, butyl methacrylate and 2-ethylhexyl methacrylate. 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 ₁₂ - alkoxyalkyl esters of acrylic acid or methacrylic acid, most preferably methoxymethyl acrylate, methoxyethyl (meth) acrylate, ethoxyethyl (meth) acrylate and methoxyethyl (meth) acrylate. Also usable are mixtures of alkyl esters, such as those mentioned above, with alkoxyalkyl esters, eg in the form of the foregoing. It is also possible hydroxyalkyl and

Hydroxyalkyl methacrylate in which the C-atom number of 1-12 hydroxyalkyl is preferably 2-hydroxyethyl acrylate, 2-hydroxyethyl and 3-hydroxypropyl acrylate; Can also be amino groups are α, β-unsaturated aminomethylacrylat Carbonsäureester as dimethyl and diethylaminoethyl acrylate.

As other copolymerizable monomers may also α, β-unsaturated dicarboxylic acids, preferably maleic acid, fumaric acid, crotonic acid, itaconic acid, citraconic acid and mesaconic acid, can be used. β-unsaturated dicarboxylic acid, preferably maleic anhydride, itaconic anhydride, citraconic anhydride and mesaconic also possible to use α.

also possible to use mono- or diesters of α, β-unsaturated dicarboxylic acids. These α, β-unsaturated dicarboxylic acid mono- or diesters for example, may be alkyl, preferably C ₁ -C ₁₀ - alkyl, in particular ethyl, n-propyl, iso-propyl, n-butyl, tert-butyl , n-pentyl or n-hexyl, alkoxyalkyl, preferably C ₂ -C ₁₂ alkoxyalkyl, more preferably C3-C ₈ - alkoxyalkyl, hydroxyalkyl, preferably C ₁ -C ₁₂ hydroxyalkyl, more preferably C ₂ -C ₈ - hydroxyalkyl, cycloalkyl, preferably C ₅ -C ₂ cycloalkyl, more preferably Ce-C - cycloalkyl, alkylcycloalkyl, preferably C6-Ci ₂ -Alkylcycloalkyl-, particularly preferably _C7-C10 - alkylcycloalkyl, aryl, preferably C6 -C ₄ aryl-mono- or diesters, act, wherein in the case of diester can each be mixed esters also. 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 α, β-unsaturated monocarboxylic acids are methoxyethyl (meth) acrylate, ethoxyethyl (meth) acrylate and methoxyethyl (meth) acrylate. In particular, methoxyethyl acrylate is used. As other esters of α, β-unsaturated monocarboxylic acids, for example, polyethylene glycol (meth) N- (2-hydroxyethyl) acrylamides, N- (2-hydroxymethyl) acrylamide and urethane are also acrylate, polypropylene glycol (meth) acrylate, (meth) acrylate.

As α, β-unsaturated dicarboxylic analog diesters can be used based on the aforementioned Monoestergrappen, and it can also be chemically different in Estergrappen.

As other copolymerizable monomers further free-radically polymerizable compounds are suitable, which contained per molecule at least two olefinic double bonds th. Such monomers lead to a certain pre-crosslinking rubber corresponding to the nitrile. Examples of polyunsaturated compounds are acrylates, methacrylates or itaconic conate of polyols such as ethylene glycol diacrylate, diethylene glycol dimethacrylate, triethylene glylkoldiacrylat, butane-l, 4 diacrylate, propane 1, 2-diacrylate, butane-l, 3-dimethacrylate, neopentyl glycol diacrylate, acrylate trimethylolpropane di (meth) acrylate, trimethylolethane di (meth) acrylate, glycerol di- and triacrylate, pentaerythritol, tri- and tetraacrylate or methacrylate, Dipentaery- thrittetra, penta- and hexaacrylate or methacrylate or itaconate, sorbitol tetraacrylate, Sorbithexa- methacrylate, diacrylates or dimethacrylates of 1, 4-cyclohexanediol, 1, 4-dimethylolcyclohexane, 2,2-bis (4-hydroxyphenyl) propane, of polyethylene glycols or of oligoesters or Oligoure- subjects having terminal Hydroxylgrappen. As polyunsaturated monomers also can be used acrylamides such as methylene-bis-acrylamide, hexamethylene-l, 6-bis-acrylamide, diethylene triamine tris-methacrylamide, ethyl bis (methacrylamido-propoxy) ethane or 2-acrylamido. Examples of polyunsaturated vinyl and allyl compounds are divinylbenzene, ethylene glycol divinyl ether, diallyl phthalate, allyl methacrylate, diallyl, triallyl or triallyl. In one execution of the invention, ethylene glycol diacrylate or trimethylolpropane di (meth) acrylate such as copolymerizable

Monomer used, preference is given to acrylonitrile and butadiene as further monomers. Here, it has proven this copolymerizable monomer in an amount of up to 10, wt.%, Preferably up to 7 wt.%, Based on the total monomer amount to use. The proportions of conjugated diene and α, β-unsaturated nitrile in the nitrile rubbers may vary within wide ranges. The proportion of or of the sum of the conjugated dienes is usually in the range of 20 to 95 wt.%, Preferably in the range of 45 to 90 wt .-%, particularly preferably in the range of 50 to 85.%>, Based on the total polymer , The proportion of or of the sum of α, β-unsaturated nitriles is usually from 5 to 80 wt.%, Preferably 10 to 55 wt .-%> weight, particularly preferably at 15 to 50 .-%>, based on the total polymer , The proportions of the repeating units of conjugated diene and α, β-unsaturated nitrile in the nitrile rubbers of the present invention add up to give 100 wt -.% To.

The additional monomers can be present in amounts of from 0 to 40 wt.%>, Preferably from 0 to 30 wt .-%>, more preferably 0 to 26 wt .-%>, based on the total polymer. In this case, corresponding proportions of the repeating units of the conjugated dienes and / or of the repeating units of the or of α, β-unsaturated nitriles are replaced by proportions of these additional monomers, with the proportions of all repeating units of the monomers continuing to 100 parts by weight %> sum.

The determination of the nitrile content is via the nitrogen content, which is determined in the nitrile rubbers in accordance with DIN 53 625 by the Kjeldahl method.

The nitrile rubbers have Mooney viscosities ML 1 + 4 @ 100 ° C of 10 to 150 Mooney units (MU), preferably from 20 to 100 MU on. The Mooney viscosity ML 1 + 4 @ 100 ° C is determined by means of a shear in accordance with DIN 53523/3 or ASTM D 1646 at 100 ° C. Typically, this measurement is carried out using non-calendered

Nitrile rubber samples.

The glass transition temperatures of the nitrile rubbers are in the range -70 ° C to + 10 ° C, preferably in the range -60 ° C to 0 ° C.

Preference is given to nitrile rubbers having repeating units of acrylonitrile and 1,3-butadiene contain, particularly preferably those having only repeating units of acrylonitrile and 1,3-butadiene. Preferably, nitrile rubbers having repeating units of acrylonitrile, 1,3-butadiene and one or more other copolymerizable monomers are further comprise. Particular preference is given to nitrile rubbers having repeating units of acrylonitrile, 1,3-butadiene and one or more α, β-unsaturated mono- or dicarboxylic acids, their esters or amides, and in particular repeating units of an alkyl ester of an α, β- unsaturated carboxylic acid, particularly preferably acrylate of methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, n-butyl (meth) acrylate, t-butyl (meth) acrylate, hexyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, octyl (meth) acrylate or lauryl (meth) acrylate or

one or more polyunsaturated compounds have, and in particular repeating units of ethylene glycol diacrylate, diethylene glycol dimethacrylate, Triethylenglylkoldiacrylat, butane-l, 4 diacrylate, propane-l, 2-diacrylate, butanediol-1,3-dimethacrylate, neopentyl glycol diacrylate, trimethylolpropane di (meth) acrylate, trimethylol ethane di (meth) acrylate, glycerol di- and triacrylate, pentaerythritol, tri- and tetraacrylate or - methacrylate, dipentaerythritol tetra, penta- and hexaacrylate or methacrylate or itaconate, sorbitol tetraacrylate, Sorbithexamethacrylat, diacrylates or dimethacrylates of 1,4-cyclohexanediol, 1, 4-dimethylolcyclohexane, 2,2-bis (4-hydroxyphenyl) propane, of polyethylene glycols or of oligoesters or oligourethanes having terminal hydroxyl groups, methylene-bis-acrylamide, hexamethylene-l, 6-bis-acrylamide, diethylene triamine tris-methacrylamide, bis (methacrylic-amidopropoxy) ethane, 2-acrylamido-ethyl acrylate, divinylbenzene, ethylene glycol divinyl ether, Dial lylphthalat, allyl methacrylate, diallyl, triallyl or triallyl.

According to the invention to be used nitrile rubber also has built-in fragments of the molecular weight regulator used. be determined in the volatile components, the concentration of which by TDS-GC / MS analysis according to VDA 278 Recommendation (version 09/2002) between 28.4 min and 34.0 min for the purpose of calculation of the emission coefficient is volatile constituents of the molecular weight regulator used.

Caking agent:

The powdered mixtures contain an addition to the above nitrile rubber, or more release agents. suitable as release agents are any materials that provide the clogging of the powdered nitrile rubbers over the desired storage period. Typically, the release agents are also in powder form

The release agent are preferably selected from silicas, in particular those having a BET specific surface area of more than 5 m ² / g, the chemically modified, particularly preferably hydrophobized, can be calcium carbonate, magnesium carbonate, silicates, particularly preferably talc, mica, bentonites or montmorillonites, fatty acid salts, more preferably alkali metal and alkaline earth metal salts of fatty acids having more than 10 carbon atoms, very particularly preferably calcium or magnesium salts of such fatty acids, especially calcium stearate, magnesium stearate and Aluminiumzinkstearat, calcium phosphate, aluminum oxide, barium sulfate, zinc oxide, titanium dioxide, polymers with high glass transition temperature , for example of more than 60 ° C, more preferably polyesters, polyolefins, polyvinyl chloride and starch, hydrophilic polymers, particularly preferably polyvinyl alcohol, polyalkylene oxide compounds, polyethylene oxide compounds such as in particular polyethylene glycols or Polyet said release agent hylenglykolether, polyacrylic acid, polyvinyl pyrrolidone and cellulose derivatives, fluorocarbon polymers, carbon nanotubes and mixtures thereof. Especially preferred release agents are selected from the group of silica, calcium carbonate, silicate, PVC and fatty acid salts.

. The one or more release agents are present in the inventive powder mixture in total in an amount in the range of typically 0.25 to 45%, preferably 1 -45% by weight, preferably 2 -. 25% by weight and particularly preferably 4. - 15 wt.% based on the entire mixture.

In an alternative embodiment, are added one or more release agent in the inventive powdery mixture in total in an amount in the range 5 to 10%) by weight, based on the total mixture. A process for the preparation of the pulverulent mixtures according to the invention:

Production of the nitrile rubbers are prepared by emulsion polymerization. The process is carried out as a molecular weight regulator in the presence of tert-nonyl mercaptan. This may be, for example,

a) from about tert-nonyl mercaptan with a purity of at least the 95th%> by weight, preferably at least the 97th acting%>, or

b) a mixture comprising at least 50 wt.%> but less than 95 wt.%> tert-nonyl mercaptan and one or more further isomeric Nonylmercaptane and / or one or more further Cio-Cie contains alkylthiols. The tert-nonyl mercaptan a) is commercially available, for example from Sigma Aldrich (CAS no. 25360-10-5) having a purity of at least 97.%> Or from Chevron Phillips as a product Sulfol® 90 having a purity of at least 97 wt.%> or by various chemical manufacturers.

Mixtures b) that at least 50 wt.%> But less than 95 wt.% Contained> tert-nonyl mercaptan and one or more further isomeric Nonylmercaptane and / or one or more additional C12-C16 alkyl thiols such as are also commercially available, as mercaptans weight 175 from Atofina having a content of tert-nonyl mercaptan 65.%> by weight and from 35 Dodecylmercaptanen.%> or Sulfol® 100 from Chevron Phillips. The molecular weight modifier used is usually added in the polymerization in an amount of 0.05 to 3. Parts by weight, preferably from 0, 1 to 1; 5. Parts by weight relative to 100. Used parts by the monomer mixture. Suitable amounts can determine in simple hands-on experiments, the skilled person.

The dosage of the molecular weight regulator or molecular weight regulators mixture takes place either exclusively at the beginning of the polymerization or at the beginning and in addition in portions in the course of the polymerization. In a batch process, the entire amount of the molecular weight regulator or molecular weight regulators mixture is typically added in the beginning, in continuous operation is an incremental addition is proven. Typically, the molecular weight regulator, or the regulator mixture is then added in at least two stages, the addition in two, three or more stages is possible. Even a continuous addition over the entire polymerization time is possible. the molecular weight regulator or the molecular weight regulator mixture is particularly preferably added in two stages. In a two-stage dosing, it has proved useful, first weight the controller / the regulator mixture in an amount of 5 to 65% by weight, preferably 10 to 60th% based on the total amount of regulator / controller mixture to add prior to the start of the polymerization and the remaining amount to controller / regulator mixture in a subsequent dosage with a conversion from 5 to 80%, preferably 10 to 55%, based on the total amount of monomers used.

In a triple and multiple dosing, it is empfieht, duzu determined by appropriate preliminary experiments the optimum amount of molecular weight regulator and the best time of the addition. The molecular weight regulator is to due to its function to some extent in the form of end groups in the nitrile rubber again, that the nitrile rubber contains CcrAlkylthio- groups. In one embodiment, the textile floor covering according to the invention thus contains in the rear support layer is a vulcanizate based on at least one nitrile rubber (1) containing Cp-alkylthio end groups and with an emission quotient E of the formula (I) of less than or equal to 0.25 mg / (kg * Mooney units), preferably less than or equal to 0.22 mg / (kg * Mooney units) and most preferably less than or equal to 0.20 mg / (kg * Mooney units). In a particular variant of this embodiment, the vulcanizate is based on at least one nitrile rubber having repeat units solely of acrylonitrile and butadiene.

Powdered mixtures based on nitrile rubbers, the polymerization is conducted based not using the specific molecular weight regulator and not up to conversions of at least 60%> on the sum of the monomers used, show a significantly worse emissions behavior. Components on the basis of vulcanizates prepared using the pulverulent mixtures according to the invention show in the related applications, no more odor. Those based on the specific nitrile rubbers mixtures are characterized simultaneously by an excellent vulcanization.

emulsifiers:

Emulsifiers water-soluble salts of anionic emulsifiers or uncharged emulsifiers can be used. anionic emulsifiers are preferably used. Suitable anionic emulsifiers modified resin acids may be used, which are obtained by dimerization, disproportionation, hydrogenation and modification of resin acid mixtures containing abietic acid, neoabietic acid, palustric acid, laevopimaric acid. A particularly preferred modified resin acid is disproportionated resin acid (Ullmann's Encyclopedia of Industrial Chemistry, 6th Edition, Volume 31, pp 345-355).

As anionic emulsifiers, fatty acids can be used. These contain from 6 to 22 carbon atoms per molecule. You can be fully saturated or contain one or more double bonds in the molecule. Examples of fatty acids include lauric acid, palmitic acid, stearic acid, oleic acid, linoleic acid, linolenic acid. The carboxylic acids are usually based on origin-specific oils or fats such. As caster oil, cottonseed oil, peanut oil, linseed oil, coconut oil, palm kernel oil, olive oil, canola oil, soybean oil, fish oil and beef tallow, etc. (Ullmann's Encyclopedia of Industrial Chemistry, 6th Edition, Volume 13, pp 75-108). Preferred carboxylic acids are derived from coconut fatty acid and from beef tallow and are partially or fully hydrogenated.

Such carboxylic acids based on modified resin acids or fatty acids are used as water-soluble lithium, sodium, potassium and ammonium salts. The sodium and potassium salts are preferred. Further anionic emulsifiers are sulphonates, sulphates and phosphates which are bound to an organic radical. As an organic radical, aliphatic, aromatic, alkylated aromatics, fused aromatics and methylene-bridged aromatics, with the methylene-bridged and fused aromatics being able to be additionally alkylated. The length of the alkyl chains is from 6 to 25 carbon atoms. The length of the alkyl chains bound to the aromatics is from 3 to 12 carbon atoms.

The sulphates, sulphonates and phosphates are used as lithium, sodium, potassium and ammonium salts. The sodium, potassium and ammonium salts are preferred. Examples of such sulphonates, sulphates and phosphates are Na laurylsulphate, Na-alkylsulphonate, Na-alkylarylsulphonate, Na salts of methylene-bridged aryl sulphonates, Na salts of alkylated naphthalenesulphonates and the Na salts methlyenverbrückter naphthalenesulphonates which can also be oligomerized, with the degree of oligomerization between 2 to 10.

Typically the alkylated naphthalenesulphonic acids and the methylene-bridged (and optionally alkylated) naphthalenesulphonic acids are present as mixtures of isomers, that also more than 1 sulphonic acid group (2 to 3 sulphonic acid groups) in the molecule. Particularly preferred are sodium Laursylsulfat, Na alkylsulphonate mixtures having from 12 to 18 carbon atoms, Na alkylarylsulphonates, Na diisobutylenenaphthalenesulphonate, methylenverbückte Polynaphthalin- mixtures and methylene-bridged arylsulphonate mixtures.

Uncharged emulsifiers are derived from addition products of ethylene oxide and propylene oxide onto compounds having a sufficiently acidic hydrogen on. These include, for example, phenol, alkylated phenol and alkylated amines. The average degrees of polymerization of the epoxides are between 2 to 20. Examples of uncharged emulsifiers are ethoxylated nonylphenols having 8, 10 and 12 ethylene oxide units. The neutral emulsifiers are usually not used alone but in combination with anionic emulsifiers. the Na and K salts of disproportionated abietic acid and of partially hydrogenated are preferred

Tallow fatty acid, and mixtures thereof, sodium laurylsulphate, Na alkylsulphonates, sodium alkylbenzenesulphonate and also alkylated and methylene naphthalenesulfonic acids.

The emulsifiers are used in a total amount of 0.2-15 parts by weight, preferably from 0.5 to 12.5 parts by weight, particularly preferably 1.0-10 parts by weight per 100 parts by weight of the monomer mixture used.

The emulsion polymerization is carried out using the emulsifiers mentioned. If obtained after completion of the polymerization latexes, which tend due to a certain instability for the early Selbskoagulation, the emulsifiers mentioned can also for

Post-stabilization of the latices are used. This may be especially necessary before removal of unreacted monomers by treatment with steam, and before a latex storage. polymerization:

Polymerization initiators are typically used to initiate the emulsion polymerization, which decompose into radicals. These include compounds which contain an -O-O- unit (peroxo compounds) or an -N = N- unit (azo compound). The peroxo compounds include hydrogen peroxide, peroxodisulfates, peroxodiphosphates, hydroperoxides, peracids, peracid esters, peracid anhydrides and peroxides having two organic radicals. Suitable salts of peroxodisulfuric acid and peroxodiphosphoric are the sodium, potassium and ammonium salts. Suitable hydroperoxides are, for example t-butyl hydroperoxide, cumene hydroperoxide and p-menthane hydroperoxide. Suitable peroxides having two organic radicals are dibenzoyl peroxide, 2,4, dichlorobenzoyl, di-t-butyl peroxide, dicumyl peroxide, t-butyl perbenzoate, t-butyl peracetate, etc. Suitable azo compounds are azobisisobutyronitrile, azobisvaleronitrile and azobiscyclohexanenitrile.

Hydrogen peroxide, hydroperoxides, peracids, peracid esters peroxodisulphate and peroxodiphosphate also be used in combination with reducing agents. Suitable reducing agents are sulfenates, sulphinates, sulphoxylates, dithionite, sulphite, metabisulphite, disulphite, sugar, urea, thiourea, xanthogenates, Thioxanthogenate, hydrazinium salts, amines and amine derivatives such as aniline, dimethylaniline, monoethanolamine, diethanolamine or

Triethanolamine. Initiator systems consisting of an oxidizing agent and a reducing agent are referred to as redox systems. When using redox systems are frequently also used salts of transition metal compounds such as iron, cobalt or nickel in combination with suitable complexing agents such as sodium ethylenediaminetetraacetate, sodium nitrilotriacetate and trisodium phosphate or Tetrakaliumdiphsophat.

Preferred redox systems are:

1) potassium peroxodisulphate in combination with triethanolamine,

2) ammonium peroxodiphosphate (in combination with Natrimmetabisulfit Na ₂ S ₂ 0 _5),

3) p-methane hydroperoxide / sodium formaldehyde sulfoxylate in combination with Fe II sulfate (FeSÜ ₄ * 7 H ₂ 0), sodium Ethylendiaminoacetat and trisodium phosphate;

4) cumene hydroperoxide / sodium formaldehyde sulfoxylate (in combination with Fe II sulfate FeSÜ ₄ * 7 H ₂ 0), sodium Ethylendiaminoacetat and tetrapotassium diphosphate,

5) pinane hydroperoxide / sodium formaldehyde sulfoxylate in combination with Fe II sulfate (FeSÜ ₄ * 7 H ₂ 0), sodium Ethylendiaminoacetat and trisodium phosphate.

The amount of oxidizing agent is from 0.001 to 1 wt. Parts by weight based on 100 parts by wt. Monomer. The molar amount of reducing agent is between 50% to 500% based on the molar amount of the oxidizing agent used.

The molar amount of complexing agents is based on the amount of transition metal used and is usually equimolar with this. To carry out the polymerization, all or individual components of the initiator system are metered in at the start of the polymerization or during the polymerization.

The portionwise addition of all or individual components of the activator during the polymerization is preferred. By the sequential addition of the reaction rate can be controlled.

The polymerization time is in the range of 1 h to 25 h, preferably 2 to 25 h and depends essentially on the acrylonitrile content of the monomer mixture and the polymerization temperature.

The polymerization temperature is in the range of 0 to 30 ° C, preferably from 5 to 25 ° C.

It is essential for the preservation of the nitrile rubbers of the invention is that the polymerization is continued to a conversion of at least 60%, based carried out in the monomer mixture employed. the polymerization up to a conversion ranging from 60 to 100% is preferred, more preferably 62 to 100%, in particular from 65 to 100%. In achieving this conversion, the polymerization is stopped. For this purpose, a stopper is added to the reaction mixture. Suitable for this purpose are, for example, dimethyl dithiocarbamate, Na nitrite, mixtures of dimethyl dithiocarbamate and Na nitrite, hydrazine and hydroxylamine and also salts derived therefrom, such as hydrazinium sulphate and hydroxylammonium sulphate, diethylhydroxylamine, diisopropylhydroxylamine, water-soluble salts of hydroquinone, sodium dithionite, phenyl-a-naphthylamine and aromatic phenols such as tert-butylcatechol or phenothiazine.

The amount of water used in the emulsion polymerization is in the range from 100 to 900 wt. Parts by weight, preferably in the range of 120 to 500th parts by, preferably in the range of 150 to 400 wt., Based on 100 parts by water parts by wt. the monomer mixture.

To reduce the viscosity during the polymerization, to adjust the pH as well as a pH buffer of the aqueous phase may be added in the emulsion polymerization salts. Typical salts are salts of monovalent metals in the form of potassium and sodium hydroxide, sodium sulfate, sodium carbonate, sodium bicarbonate, sodium chloride and potassium chloride. Sodium and potassium hydroxide, sodium hydrogencarbonate and potassium chloride are preferred. The amounts of these electrolytes are in the range 0 to 1 parts by wt., Preferably 0 to 0.5 wt. Parts by weight based on 100 parts by wt. Of the monomer mixture. The polymerization may be either batchwise or continuously carried out in a stirred tank battery.

To achieve a uniform course of the polymerization of the polymerization, only part of the initiator system used and the remainder is fed in during the polymerization to start. Usually the polymerization with 10-80%% of the total amount of initiator starts wt., Preferably 30-50 wt.. The introduction of individual constituents of the initiator system is possible. If chemically uniform products, acrylonitrile or butadiene is introduced when the composition goes outside the azeotropic butadiene / acrylonitrile ratio should lie. Preferably, a replenishment case of NBR grades having acrylonitrile contents of 10-34 wt.% Is by weight, and at the types with 40 to 50.% Of acrylonitrile (W. Hofmann, "nitrile rubber", Berliner Union, Stuttgart, 1965, page 58-66) . the further introduction is the case - for example in DD 154 702 - preferably computer-controlled on the basis of a computer program.

In order to remove unreacted monomers, the stopped latex to a steam distillation may be subjected. Here, temperatures ranging from 70 ° C to 150 ° C wherein at temperatures <100 ° C the pressure is reduced are applied. Before a steam distillation, the latex emulsifier can take place. For this purpose, it is advantageous to use the abovementioned emulsifiers in amounts of from 0.1 to 2.5 wt.%), Preferably 0.5 to 2.0 wt.%> Based on 100 parts by wt. Nitrile rubber.

Preparation of the nitrile rubber-containing powder mixtures according to the invention:

The production of the nitrile-containing powdery mixtures can be done in different ways and include in each case, that the specific, as defined above nitrile (1) with which it is brought into contact one or more separation means (2). Typically, the preparation of the nitrile rubber component (1) either a grinding step (way 1), or a spray drying step (Route 2), which takes place within each contacting with the / the separating means.

Path 1:

fall as described above nitrile rubbers by emulsion polymerization and working up ultimately in the form of rubber crumbs, which are often pressed into bales of rubber. For the preparation of the powdery mixtures of the invention, the rubber bales or crumbs are by mechanical treatment, that is a grinding and / or micronisation, which may optionally take place in several stages, crushed to the desired particle size. In order to prevent adhesion of the elastomeric particles in the manufacturing process, at least one release agent is metered in. The thus-obtained powdery mixtures based on nitrile rubber and release agents is their particle size distribution for several months storage stable in their polymer characteristics and on.

Weg 1 thus comprises following the emulsion polymerization coagulation of the latex, the subsequent washing and drying of the coagulated nitrile rubber with isolation of rubber crumbs, optionally, the mixture was compressed to rubber bales, and finally the crushing and grinding of the rubber bales or crumbs by mechanical treatment, optionally in can be made several steps. It is possible, for example in a first step a

carry out coarse grinding and fine grinding in the second step, also known as micronization. The addition of the release agent is typically carried out during the milling process and can be done incremented in one portion or in several portions. Latex coagulation:

Before or during coagulation of the latex, one or more aging inhibitors are added. Therefor own Phenolic, amine and other anti-aging agents.

Suitable phenolic aging inhibitors are alkylated phenols, styrenated phenol (CAS no. 61788-44-1), sterically hindered phenols such as 2,6-di-tert-butylphenol, 2,6-di-tert-butyl-p-cresol ( Vulkanox BHT, CAS Nr.000128-37-0), 2,6-di-tert-butyl-4-ethylphenol, 2,2'-methylene-bis (6-tert-butyl) -p-cresol (Vulkanox . BKF, CAS No. 000119-47-1), poly (dicyclopentadiene-co-p-cresol), estergruppen-containing hindered phenols such as n-octadecyl (beta) - (4-hydroxy-3,5-di- tert-butyl-phenyl) propionate, thioethers, sterically hindered phenols, 2,2'-methylene-bis- (4-methyl-6-tert-butylphenol) (BPH), 2-methyl-4,6-bis (octylsulfanylmethyl) phenol and hindered thiobisphenols. In further embodiments, two or more anti-aging agents may be added, such as propionate, a mixture of n-octadecyl-SS (4-hydroxy-3,5-di-tert-butyl-phenyl), poly (dicyclopentadiene-co-p-cresol ) and 2-methyl-4,6-bis (octylsulfanylmethyl) phenol.

If discoloration of the rubber is of no importance, amine aging retardant z. Mixtures of diaryl-p-phenylenediamines (DTPD) B., octylated diphenylamine (ODPA), phenyl-a-naphthylamine (PAN), phenyl-beta-naphthylamine (PBN), preferably those based on phenylenediamine. Examples of phenylenediamines are N

Isopropyl-N'-phenyl-p-phenylenediamine, Nl 3-dimethylbutyl-N'-phenyl / phenylenediamine (6PPD), Nl, 4-dimethylpentyl-N'-phenyl - /? - phenylenediamine (7PPD) NN'- bis-l, 4- (l, 4-dimethylpentyl) - / phenylenediamine (77PD), etc. the other aging inhibitors include phosphites such as tris (nonylphenyl) phosphite, polymerized 2,2,4-trimethyl-l, 2-dihydroquinoline ( TMQ), 2-mercaptobenzimidazole (MBI), methyl-2-mercaptobenzimidazole (MMBI), Zinkmethylmercaptobenzimidazol (ZMMBI). The above other anti-aging agents are often used in combination with phenolic aging inhibitors. Other anti-aging agent TMQ, MBI and MMBI are mainly used for NBR grades which are vulcanized peroxide.

For the coagulation of the latex is adjusted to a known to those skilled pH namely by addition of a base, preferably ammonia, or sodium or potassium hydroxide, or an acid, preferably sulfuric acid or acetic acid.

In one embodiment of the process, the coagulation is carried out using at least one salt selected from the group consisting of aluminum, calcium, magnesium, sodium, potassium, and lithium salts performed. Anions of these salts on or bivalent anions are normally used. Halides are preferred, particularly preferably chloride, nitrate, sulphate, hydrogencarbonate, carbonate, formate and acetate.

Suitable sodium chloride, potassium chloride, calcium chloride, magnesium chloride, sodium nitrate, potassium nitrate, sodium sulfate, potassium sulfate, sodium hydrogencarbonate, potassium hydrogencarbonate, sodium carbonate, potassium carbonate, aluminum sulfate, potassium aluminum sulfate are, for example (potassium alum), sodium aluminum sulphate (sodium alum), sodium acetate, calcium acetate and calcium formate. If necessary for coagulation of latex a water soluble calcium salt is used, calcium chloride is preferred. The salts are present in an amount of 0.05 to 10.%, Preferably 0.5 to 8 wt.%, Particularly preferably 1 to 5 wt.%, Based on the added solids content of the latex dispersion

Besides at least one salt from the group defined above and precipitation aids can be used in coagulation. As precipitation aids, for example, water-soluble polymers are suitable. These are nonionic, anionic or cationic.

Examples of non-ionic polymeric precipitation aids are modified cellulose such as hydroxyalkyl cellulose or methylcellulose and also adducts of ethylene oxide and propylene oxide onto compounds having an acidic hydrogen. are examples of compounds containing acidic hydrogen: acid fat, sugars such as sorbitol, and mono- Difettsäureglyceride, phenol, alkylated phenols, (alkyl) - phenol / formaldehyde condensates, etc. The addition products of ethylene oxide and propylene oxide onto these compounds can be random and block be constructed. Of these products, preferred are those in which the solubility decreases with increasing temperature. Examples of anionic polymeric precipitation aids are the homopolymers and copolymers of (meth) acrylic acid, maleic acid, maleic anhydride, etc. Preferably, the sodium salt of polyacrylic acid. Cationic polymeric precipitation aids are usually based on polyamines and on homo- and

Copolymers of (meth) acrylamide. Preferred are Polymethacxrylamide and polyamines, in particular those based on epichlorohydrin and dimethylamine. The amounts of polymeric precipitation aids are from 0.01 to 5 parts by weight, preferably 0.05 to 2.5 parts by weight per 100 parts by weight of nitrile rubber.

The use of other precipitation aids is also conceivable. but it is possible without any problems, carry out the process according to the invention in the absence of additional precipitation aids.

The latex used for the coagulation advantageously has a solids concentration in the range of 1 -. 40% by weight, preferably in the range of 5- 35%, and particularly preferably in the range of 15 -. 30 wt.%.

The coagulation of the latex is carried out in the temperature range from 10 to 110 ° C, preferably from 20 to 100 ° C, particularly preferably 50 to 98 ° C. The coagulation of the latex can be continuous or discontinuous, preferably operating continuously.

In an alternative embodiment of the usually separated from unreacted monomers latex may also be with acids in a pH range of <6, preferably <4, particularly preferably 2 to be treated, whereby the polymer precipitates. In order to precipitate all mineral and organic acids can be used that allow the selected pH

adjust areas. Mineral acids are preferably used for pH adjustment. The polymer is in the usual way to those skilled separated from the suspension. This too can be continuous or discontinuous, preferably operating continuously.

Washing and drying the coagulated nitrile rubber:

After coagulation, the nitrile rubber is usually in the form of crumb. The washing of the coagulated NBR is therefore also referred to as crumb washing. For this underwear either deionized water or deionized water may be used. The washing is carried out at a temperature in the range of 15 to 90 ° C, preferably at a temperature in the range of 20 to 80 ° C. The amount of washing water is 0.5 to 20 wt. Parts by, preferably 1 to 10 parts by wt., And particularly preferably 1 to 5 wt. Parts by weight based on 100 parts by wt. Nitrile rubber. Preferably, the rubber crumb is subjected to multistage washing, with the rubber crumb to be dewatered between the individual washing stages in part. The residual moisture contents of the crumb between the individual washing stages are in the range of 5 to 50 wt.%, Preferably in the range 7 to 25%. The number of washing stages is usually from 1 to 7, preferably from 1 to 3. Washing is carried out batchwise or continuously. Preferably, a multistage, continuous process, wherein for the careful treatment with water, a countercurrent washing being preferred. After washing is complete, it has proved useful to dewater the nitrile rubber crumb. Drying of the nitrile rubber to preliminary dewatering is carried out in a dryer are geeigent for example, fluidized bed dryer or tray dryer. The temperatures during drying are 80 to 150 ° C. with a drying temperature program, the temperature is lowered towards the end of the drying process is preferred.

For crushing and grinding are recommended technique known apparatuses and grinders.

Path 2:

In the second possible method one starts directly from the obtained in the emulsion polymer latex, which is a typically stabilized by emulsifiers suspension of solid polymer particles in water. From this latex, the powdery elastomer is directly recovered by the water from the latex is separated by means of a spray drying the polymer and the polymer thereby obtained in the form of a fine powder. The one or more release agents are thereby metered as described below.

The spray drying of the latices of the emulsion polymerization generally takes place in conventional spray towers. Here, the preferably 15 to 100 ° C heated latex via pumps transported into the spray tower and for example in the top of the tower located nozzle bar, preferably at pressures of 50 to 500, preferably 100 to 300 bar sprayed. In one embodiment there is in the spray tower, a negative pressure in the reporting of 100 to 500 mbar, preferably 150 to 400 mbar. Hot air with an inlet temperature of preferably 100 to 350 ° C is supplied to, for example, in counter-current and the water evaporates. The powder falls down and the dry powder is discharged at the foot of the tower. The one or more release agents and optional other additives such as anti-aging agents, antioxidants, optical brighteners, etc., are preferably also blown as dry powders to the head of the tower. You may also be partially or completely mixed with the latex prior to spray drying. Supplied to the spray tower latexes preferably have solids concentrations of 10 - 60 wt%, particularly preferably 20-50% by weight and especially 30-50%> based on the latex on.... By both routes a stable powder form can be obtained due to the employed specific emission NBRs in combination with the release agent that has a significantly reduced VOC content. It is important that this reduction in VOC content is already achieved during the preparation of the mixture, so that described in the subsequent processing into composite as described below no harmful to health exposure is given more. Fortunately, the reduction of VOC content is possible according to the invention, without the polymer of a larger temporal and thermal stress has to be exposed, which is partly a negative effect in the methods of the prior art on the polymer structure, to the aging characteristics, the flexibility or the color stability of the products may or impact.

The invention composites are further including

(A) at least one pulverulent mixture of the invention containing at least one nitrile rubber specially defined as above (1) and one or more Trennmmittel (2) the above-defined average particle diameter D in the range of _a

comprising 0.01 to 4 mm, and

(B) one or more thermoplastic polymers.

In a preferred embodiment, component (B) is selected from the group consisting of polyvinyl chloride, polyurethanes, polyamides, epoxy resins, phenolic resins, polypropylene, polyethylene, polyethylene and polystyrene.

In a particularly preferred embodiment, component (B) is selected from the group consisting of polyvinyl chloride, polyurethanes and polyamides.

It has proven useful, the components (A) (nitrile rubber) and (B) (thermoplastic) at a weight ratio of (1-99): (99-1), preferably (10-60): use (90-40).

These composites are characterized by an excellent and homogeneous dispersion of pulverulent mixtures in the thermoplastic, and thus lead to the desired improvements in properties such as an excellent impact strength.

The invention further provides a process for the preparation of the composites as defined above, by reacting the two components (A) and (B) are mixed together.

The mixing of the components is typically carried out either in an internal mixer, on a roller or by means of an extruder. As internal mixer such be used with so-called "interlocking" rotor geometry normally. The loading of the internal mixer, roll or extruder is carried out to start timing a with the inventive powdery mixture and / or the or more thermoplastics. The mixing is accomplished under control of the temperature with the proviso that the mix for a suitable period remains at such a temperature which causes melting of the thermoplastic component (B). Typically, selected temperatures in the range from 100 to 280 ° C. As far as other additives are still to be added, they become suitable time points were added. After a further suitable mixing period, the internal mixer is vented and emptied to afford the composites. All of the above periods are usually in the range of a few minutes and can be determined by the skilled artisan without difficulty depending on the mixture to be produced If. Rollers used as mixing unit, one can proceed with the metered addition in an analogous manner and sequence. Alternatively meaningful Dosage orders are possible and will become apparent to the skilled worker by a few mixing tests. In alternative embodiments, it may be advisable additionally to add further components in the production of composites.

For all other versions, is "phr", without this being mentioned every time for "parts per hundred of rubber" and thus refers to 100 parts by wt. Of all rubbers which are used for the production of composites. Provided that the composite contains as the rubber only the nitrile rubber component (1), the phr information for the other components thus refer to 100 parts by weight of the nitrile rubber.

Optionally be employed in the preparation of the composites, one or more crosslinking agents. , 3,3,5-tert trimethylcylohexan - here is one example, peroxidic crosslinkers such as bis (2,4-dichlorobenzyl) peroxide, dibenzoyl bis (4-chlorobenzoyl) peroxide, 1-bis (t-butylperoxy) butyl perbenzoate, bis (t-butylperoxy) butene, 4,4-di-tert-butyl peroxynonylvalerat 2.2, dicumyl peroxide, 2,5-dimethyl-2,5-di (t-butylperoxy) hexane, tert-butyl cumyl peroxide, l , 3-bis (t-butylperoxy isopropyl) benzene, di-t-butyl peroxide and 2,5-dimethyl-2,5-di (t-butylperoxy) hexyne-third

It may be advantageous not only these peroxidic crosslinkers but also to use further additives by means of which the crosslinking yield can be increased: For this example, triallyl isocyanurate, triallyl cyanurate, trimethylolpropane tri (meth) acrylate, triallyl, ethylene glycol dimethacrylate, trimethylolpropane are trimethacrylate, Zn diacrylate, Zn dimethacrylate, 1, 2-polybutadiene or N _j N 'm-phenylene dimaleimide suitable. When they are used, the total amount of the crosslinker or crosslinkers is usually in the range of 0.05 to 20 phr, preferably in the range of 0.1 to 10 phr, particularly preferably in the range from 0.2 to 8 phr, and particularly preferably in the range from 0.2 to 5 phr. As a crosslinking agent and sulfur can in elemental soluble or insoluble form or

Sulfur donors are used.

Is sulfur used as crosslinking agents, it is usually in an amount of from 0 phr, 1 to 10, preferably 0.2 to 5 and particularly preferably from 0.2 to 3 phr.

Sulfur donors, for example dimorpholyl (DTDM), 2-morpholino dithiobenzothiazol (MB SS), caprolactam, dipentamethylenethiuram (DPTT), and tetramethylthiuram (TMTD) in question. If a sulfur donor as a crosslinking agent (2) is used, the amount is usually 1 to 10 phr, preferably 1 to 6 phr, and most preferably 1 to 4 phr.

It may be useful to use in the manufacture of the composite, one or more fillers: these are, for example, carbon black, silica, barium sulfate, titanium dioxide, zinc oxide, calcium oxide, calcium carbonate, magnesium oxide, aluminum oxide, iron oxide, aluminum hydroxide, magnesium hydroxide, aluminum silicates, diatomaceous earth, talc, kaolins, bentonites, carbon nanotubes, Teflon (the latter preferably in powder form) or silicates in question.

The filler may phr in an amount of 1 to 600, preferably 10-500 phr, more preferably from 20 to 400 phr, and especially 50-300 phr are used.

It is possible to use in addition to the crosslinking agents, one or more crosslinking accelerators, by which the crosslinking yield can be increased. Basically, the

But networking also take place with one or more crosslinking agents alone. Provided that one or more crosslinking accelerators are used, the amount is usually up to 15 phr, preferably from 0.05 to 13 phr, more preferably 1 - 12 phr, more preferably 1 - 10 phr used.

Unless crosslinking accelerator in blends above substances are used with, for example paraffins, the abovementioned indication PHR to the respective active substance refers.

As such additives, by means of which the crosslinking yield can be increased, for example, dithiocarbamates, thiurams, thiazoles, sulfenamides, xanthates, guanidine derivatives, caprolactams and thiourea derivatives are suitable. As dithiocarbamates can eg ammonium dimethyldithiocarbamate, Natriumdiethyldithio- carbamate (SDEC), Natriumdibutyl dibutyldithiocarbamate (SDBC), zinc dimethyldithiocarbamate (ZDMC), zinc diethyldithiocarbamate (ZDEC), zinc (ZDBC) Zinkethylphenyl- dithiocarbamate (ZEPC), zinc dibenzyl dithiocarbamate (ZBEC), zinc pentamethylenedithiocarbamate (Z5MC ), tellurium diethyldithiocarbamate, nickel dibutyldithiocarbamate, and zinc diisononyldithiocarbamate Nickeldimethylithiocarbamat be used.

As thiurams such as tetramethylthiuram (TMTD), tetramethylthiuram can (TMTM) Dimethyldiphenylthiuramdisulfid, Tetrabenzylthiuram disulfide, thiuram tetrasulfide Dipentamethylen- and tetraethyl (TETD) are used.

As thiazoles can, for example 2-mercaptobenzothiazole (MBT), Dibenzthiazyldisulfid (MBTS), Zinkmercaptobenzothiazol (ZMBT) and copper-2-mercaptobenzo-thiazole be used.

As Sulfenamidderivate can, for example N-cyclohexyl-2-benzothiazylsulfenamide (CBS), N-tert-butyl-2-benzthiazylsulfenamid (TBBS), N, N'-dicyclohexyl-2-benzthiazylsulfenamid (DCBS), 2- Morpholinothiobenzthiazol (MBS), N-oxydiethylene N-tert.butylsulfenamid or oxydiethylenethiocarbamyl-N-oxyethylensulfenamid be used.

As xanthates eg Natriumdibutylxanthogenat, Zinkisopropyldibutylxanthogenat or zinc dibutylxanthogenate can be used.

As guanidine derivatives such as diphenylguanidine may also be used (DPG), di-o-tolylguanidine (DOTG), or o- tolylbiguanide (OTBG).

As dithiophosphates such as zinc dialkydithiophosphate (chain length of the alkyl radicals C2 to _east CI), copper dialkyldithiophosphates (chain length of the alkyl radicals C2 to CI _Ö) or Dithiophoshorylpolysulfid can be used.

As caprolactam dithiobis-caprolactam for example, can be used.

As thiourea derivatives, for example, Ν, Ν'-diphenyl thiourea (DPTU), diethyl (DETU) and ethylene thiourea (ETU) can be used.

Likewise suitable as additives are, for example: zinc compounds, hexamethylenetetramine, l, 3-bis (citraconimidomethyl) benzene and cyclic disulfanes. The crosslinking accelerator mentioned can be used both individually and in mixtures. The following substances for crosslinking the nitrile rubbers are preferably used: 2-mercaptobenzothiazole, tetramethylthiuram disulfide, tetramethylthiuram monosulfide, zinc dibenzyldithiocarbamate, dipentamethylenethiuram tetrasulfide, Zinkdialkydithiophosphat, dimorpholyl, tellurium diethyldithiocarbamate, nickel dibutyldithiocarbamate, Zinkdibutyl- dithiocarbamate, zinc dimethyldithiocarbamate and Dithiobiscaprolactam.

In a sulfur crosslinking, it may be also useful in addition to the crosslinking agents and the above-mentioned crosslinking accelerators to be used as component (4), other inorganic or organic substances, for example: zinc oxide,

Zinc carbonate, lead oxide, magnesium oxide, saturated or unsaturated organic fatty acids such as stearic acid and their zinc salts, polyalcohols, amino alcohols such as triethanolamine and also amines such as dibutylamine, dicyclohexylamine, cyclohexylethylamine and polyether amines.

In addition, scorch retarders can be used. These include cyclohexylthiophthalimide (CTP), Ν, Ν 'Dinitrosopentamethlyentetramin (DNPT), phthalic anhydride (PTA) and diphenylnitrosamine. Cyclohexylthiophthalimide is preferred (CTP). It is also possible to use filler in the manufacture of composites according to the invention. For this, preferred are organic silanes, particularly preferably vinyltrimethyloxysilane, vinyldimethoxymethylsilane, vinyltriethoxysilane, vinyltris (2-methoxy- ethoxy) silane, aminopropyltrimethoxysilane, N-cyclohexyl-3, 3 - aminopropyltrimethoxysilane, methyltrimethoxysilane, Methyltlriethoxysilan, dimethyldimethoxysilane, dimethyldiethoxysilane, trimethylethoxysilane, isooctyltrimethoxysilane, isooctyltriethoxysilane, hexadecyltrimethoxysilane or (octadecyl) methyldimethoxysilane into consideration. Further filler activators are, for example, surface-active substances such as triethanolamine and ethylene glycols having molecular weights is from 74 to 10,000 g / mol.

Unless filler are used, their amount is usually up to 10 phr, preferably from 0.01 to 10 phr, more preferably from 0.25 to 10 phr, and more particularly 0.5 to 7 phr.

It is also possible to use one or more anti-aging agents in the preparation of the composites of the invention. Here, all those can be added, which are described above in connection with the coagulation of the latex in this application. They are usually phr in amounts of up to 5, preferably from 0.25 phr, more preferably from 0.25 to 4 phr, and used, in particular 0.5 3 phr. It is also possible to use ozone protection agents in the production of composites according to the invention, preferably paraffinic waxes, microcrystalline waxes, nickel, phenylenediamines, Vulkazon AFS / LG (CAS no. 006600-31-3) or Vulkazon AFD (CAS no. 022428-48- 4) can be used. If they are used, the amounts are usually up to 5 phr, preferably 0.25 phr, more preferably from 0.25 to 4 phr, and more particularly 0.5 3 phr.

Moreover, it is also possible to use one or more plasticizers in the manufacture of composites according to the invention, preferably as the following: phthalates such as DOP or DINP, adipates such as DOA, mellitates or trimellitates as TOTM, sebacates such as DOS, diester ether mixtures such as Rhenosin® W759, thioethers such as Vulkanol® OT, phosphates such as Disflamoll®, Mesamoll® or polymeric plasticizers such as Ultramoll® and bio-based plasticizer such as

ESBO.

The / The plasticizer is used usually in an amount of up to 180 phr, preferably from 0.5 to 150 phr, more preferably from 1 to 125 phr, and especially from 1 to 100 phr.

The invention further provides the use of the composites for the manufacture of components, preferably for use in automotive interior and the components based on these

Composites.

EXAMPLES:

L analysis

acrylonitrile content:

The nitrogen content to determine the acrylonitrile content was inventive in the

Nitrile rubbers in accordance with DIN 53625 is determined by the Kjeldahl method.

Mooney determination:

The determination of the Mooney viscosity (ML 1 + 4 @ 100 ° C) was performed according to ASTM D 1646 at 100 ° C.

Particle Size Determination:

The particle size of the powdered mixture was determined granulometry. For this purpose, 100 g of the powdery mixture was weighed 2.0 mm in a sieve mesh size. Below this screen further sieves were placed with a mesh size of 1.4 mm, 1.0 mm, 0.8 mm, 0.6 mm and 0.3 mm. The composite fabrics are clamped on a vibratory screening machine (AS 200 control, g ', Fa. Retsch) and treated with an amplitude of 2.00 mm for a period of 30 min. Thereafter, the individual sieves were weighed and the average particle size D _A is calculated according to the following formula:

wherein

D _{a is} the average particle diameter in mm means

X; represents the percentage retained in the respective sieve particle total mass in g and -%

D; is the mean mesh width of the sieve respective n and n + 1 in mm. continue to apply

Di = (D _n D + _{(n + 1))} / 2

wherein

D _n of the mesh diameter of the sieve n in mm, and

D _(n + i) n the mesh diameter of the screen + 1 denotes in mm.

The volatile organic constituents of the nitrile rubbers were quantified according to VDA 278 (version 2011) by means of a thermal desorption gas chromatography (TDS-GC / MS).

II. Preparation of NBR polymers A and B

As a basis for the preparation of the examples of the invention and the comparative examples were two NBR polymers A and B, as indicated, prepared and used in Table 1 below. Table 1: Production of the NBR polymers A and B

(Amounts in parts by weight based on 100 parts total monomer (butadiene and acrylonitrile))

1) The addition of the increment was carried out at a Monomeramsatz 36%

2) oleic acid: CAS Number 67701 -06-8

3) resin acid: CAS Number 61790-51 -0

4) AOS: sodium α olefin sulfonate

5) Sulfole 120: t-DDM (tertiary dodecyl mercaptan); Chevron Phillips Chemicals

6) Sulfole 90: (tertiary nonyl mercaptan); Chevron Phillips Chemicals

7) p-menthane hydroperoxide (Trigonox NT 50 from Akzo-Degussa)

8) containing the reducing agent is Rongalit C (sodium salt of a sulfinic acid derivative) and the Fe (II) salt in the amounts indicated above.

9) 2 - [(2-hydroxy-5-methyl-3-tert-butyl-phenyl) methyl] -4-methyl-6-tert-butyl-phenol; Lanxess Germany GmbH

10) measured at the beginning of the polymerization,

The production of the nitrile rubbers A and B was carried out continuously in a stirred tank battery. After the introduction of the monomers, soap AOS and the molecular weight regulator (as indicated in Table 1 based on 100 parts total monomer) the reaction was stopped after the temperature of the reactor contents by adding aqueous solutions of iron (II) salts (in the form of premix solutions) and para-menthane hydroperoxide (Trigonox ^® NT50) is started. The reaction mixture was pumped through the stirred kettle cascade and at reaching the desired conversion by adding an aqueous solution of diethylhydroxylamine last

Reactor stopped. Unreacted monomers and other volatile constituents were removed by stripping under vacuum.

Before the coagulation of the NBR latex was in each case with a 50% dispersion of Vulkanox BKF ^® (0.3 mass% Vulkanox BKF ^® based on NBR solid) was added. The mixture was then coagulated, washed and dried crumbs obtained.

III. Preparation of powdered mixtures of NBR A or B and a release agent (Examples 1 and 2)

The powdery mixtures of NBR and a release agent were based on the NBR

Polymers A and B prepared as follows. The indicated amount NBR crumb (in g) was mixed with the stated amount of each release agent calcium carbonate intimately (in g). This mixture was added gradually to a ultracentrifugal mill ZM 200 (Retsch®), was connected to the cyclone. The mill was equipped with a ring sieve of the average mesh size of 1 mm and was operated at a speed of 18000 rpm. The powder was continuously removed during the grinding operation by means of the cyclone from the grinding chamber and collected.

Table 2: preparation of the powder mixtures (Examples 1 and 2)

((Examples 3 and 4 ,, dry blend ")) IV. Preparation of powdered mixtures of NBR, a release agent and a thermoplastic

The so-called dry blends were prepared by mixing the amounts specified in Table 3 (in g) in a planetary mixer. The mixer was heated to 100 ° C. The powdered PVC was ** added to the mixing apparatus together with the stabilizer Mark CZ 97, after 5

Minutes of mixing time, the NBR powder mixtures were added. After a further 10 minutes of mixing time is takes to dry blend the mixing unit and allows the material prior to further processing to cool to room temperature.

Table 3: Preparation of mixtures of NBR, a release agent and a

Thermoplastic resins (Examples 3 and 4)

* Polyvinyl chloride, powdered, Vinnolit GmbH & Co. KG

** calcium / zinc stabilizer of Galata Chemicals

V. Extruded blends of NBR, a release agent and a thermoplastic ( "composite") (Examples 5 and 6)

The army position of the composite was carried out using a laboratory extruder "Plasti-Corder Lab Station" manufactured by Brabender®. The single screw extruder had four heating zones. The temperatures of the individual zones were starting from the sample feed to 155 ° C, 160 ° C, 165 ° C set to 170 ° C. The screw was operated at a speed of 100 rpm. The tool has a slit-shaped nozzle was used with a width of 2.5 mm. The powdered Examples 3 and 4 ( "dry blends"), the extruder was fed. After about 30 seconds feeding a homogeneous extrudate was obtained ( "composite").

VI. Summary of Analysis for all examples

In the following Table 4, the analytical results of the output NBR A and B samples, and the powdery mixture with the release agent, the blend with PVC as thermoplastic and the corresponding composites are listed.

It can clearly be seen that Example based on a NBR with an emission coefficient of 0.041 mg / according to the invention (kg * Mooney units), which thus less than 0.25 mg / (kg * Mooney units) is, accordingly leads to composites, the low-emission materials represent, and thus can be used for critical interior applications without problems or restrictions. Table 4: Analysis of the nitrile rubbers A and B and of Examples 1-6 ( "nd" means not determined)

Total VOC was determined according to VDA 278th

[Volatiles] [nitrile]

E = x

[Mooney viscosity] 100 wherein

[Volatiles] is the concentration of volatile components in mg / kg nitrile rubber, by a TDS-GC / MS analysis according to VDA 278 Recommendation (version 09/2002) between 28.4 min and 34.0 min are determined,

[Mooney viscosity] the ASTM D 1646 specific Mooney viscosity ML 1 + 4 at 100 ° C of

Nitrile rubber, expressed in Mooney units, representing, and

[Nitrile] Kjeldahl, representing the content of the α, β-unsaturated nitrile in the nitrile rubber in wt.%, Determined according to DIN 53 625.