Pressed products made of a crosslinkable material, method for the production and further processing thereof to produce elastomer-based moulded bodies

Abstract

The present invention relates to a method for producing pressed products made of a crosslinkable material based on an elastomer-containing powder or granulate, in particular a recycled material such as scrap tyres. The method also relates to the pressed products obtained therefrom and to the further processing thereof. The pressed products are very well suited for further processing to form crosslinked elastomer compounds and moulded bodies formed therefrom, and for the substitution of raw rubber or compositions containing raw rubber.

Description

[0001] Compacts made from a cross-linkable material, methods for their production and further processing into elastomer-based molded bodies

[0002] Description

[0003] The present invention relates to a process for producing compacts from a crosslinkable material based on an elastomer-containing powder or granules, in particular from recycled material such as scrap tires, the compacts obtainable therefrom, and their further processing, in particular in processes for producing elastomer compositions and molded articles formed therefrom. The compacts according to the invention are highly suitable for substituting raw rubber or raw rubber-containing compositions in existing value chains.

[0004] Technical background

[0005] Rubber-elastic products are conventionally manufactured by shaping and crosslinking viscous formulations based on crosslinkable materials such as raw rubber. In principle, elastomer-based powders or granules can also be processed into rubber-elastic products by compression. Powders or granules such as those obtained from the recycling of used elastomer materials, such as scrap tires, can be used, which is desirable from a sustainability perspective. With a volume of approximately 1,000 million scrap tires generated worldwide each year, scrap tires represent a significant environmental problem and, at the same time, a great economic potential for recycling opportunities, see, for example, K. Formela "Sustainable development of waste tires recycling technologies - recent advances, challenges and future trends," Advanced Industrial and Engineering Polymer Research 4 (2021), 209-222.

[0006] However, elastomer-based powders or granules generally consist of a large number of individual particles of a pre-crosslinked elastomeric material. Therefore, product properties such as material cohesion, mechanical properties, or aging resistance are often comparatively poor when manufacturing rubber-elastic products from elastomer-based powders or granules, resulting in limited usability. Furthermore, elastomer-based powders or granules generally have a low bulk density, which is significantly (e.g., by a factor of 2-4) lower than the density of the rubber-elastic products to be manufactured. Raw rubber, on the other hand, has a density similar to that of the final product.When using elastomer-based powders or granules to manufacture rubber-elastic products, tools used for processing raw rubber-based feedstocks, such as compression molding or transfer molding, are often unsuitable or difficult to use. Instead, specially designed tools are required that are designed for greater volume reduction during processing. In addition, the handling and dosing of elastomer-based powders or granules in the manufacturing process is more complex than for raw rubber-based feedstocks and is not compatible with existing equipment in raw rubber-based processing processes.These factors therefore make it difficult to replace raw rubber or raw rubber-containing compositions with elastomer-based powders or granules in existing value chains, which is desirable from a sustainability and cost perspective.

[0007] The present invention is therefore based on the object of providing means and processes for using elastomer-based powders or granules for the production of rubber-elastic products, which at least partially reduce or eliminate the above-described disadvantages of the prior art. In particular, the means and processes should be feasible cost-effectively and efficiently, allowing the use of large-scale recycled materials such as scrap tire granules, enabling simple substitution of raw rubber or raw rubber-containing compositions with elastomer-based powders or granules in existing value chains, and enabling the production of rubber-elastic products with product properties that can meet even more demanding applications.

[0008] Summary of the invention

[0009] The underlying problem is solved according to the invention by a process for producing a compact from a crosslinkable material as defined in the appended independent claim 1 and the compacts obtainable by this process. The process comprises:

[0010] (a) Providing a mixture comprising:

[0011] (i) a powder or granulate containing at least one elastomer, and

[0012] (ii) one or more additives comprising at least one solid binder having a melting or softening temperature (T m ) in the range of 100°C or less, and ethylenically unsaturated functional groups,

[0013] (b) compacting the mixture heated to a temperature of less than 120°C using a forming tool to form a compact, and

[0014] (c) demoulding the compact, after cooling, at a temperature of less than T mto obtain the compact made of a crosslinkable material. Furthermore, the invention relates to a process for producing molded articles using the compacts according to the invention. The process may comprise providing a compact made of a crosslinkable material as described herein and crosslinking the crosslinkable material to form a crosslinked elastomer mass. The process for producing a molded article may also comprise the following steps:

[0015] (a) providing an insert material for a forming tool, wherein the insert material comprises at least one compact of a crosslinkable material described herein or one or more parts thereof,

[0016] (b) shaping the insert material into a desired shape using the shaping tool, and

[0017] (c) Crosslinking the feedstock to form a crosslinked elastomer composition.

[0018] The invention also relates to shaped bodies and articles comprising a crosslinked elastomer composition which are obtainable by this process.

[0019] Furthermore, the invention is directed to the use of a compact made of a crosslinkable material as described herein, or one or more parts thereof, for producing an article comprising a crosslinked elastomer composition and / or for substituting raw rubber or raw rubber-containing compositions.

[0020] The compacts according to the invention can be produced cost-effectively and efficiently using commercially available starting materials and existing powder processing technology. High proportions, for example, 70 wt.% or more, based on the total weight of the compact, of widely available recycled materials such as scrap tire granulate can be used. The compacts produced according to the invention generally have a significantly higher density than the bulk density of the starting mixture and can therefore be stored and transported in a space- and cost-efficient manner. Compacts with good material cohesion and high strength can be produced. The compacts according to the invention can be easily handled and further processed using conventional raw rubber-based processing equipment, without the need for specially manufactured tools.In the compacts according to the invention, the particles of the elastomer-based powder or granules can be activated for crosslinking. The compacts can serve as a ready-to-use intermediate product (masterbatch) that can be effectively processed into crosslinked elastomer compositions and molded articles formed therefrom. The resulting rubber-elastic products can exhibit properties that meet even more demanding applications. The compacts according to the invention thus promote the desirable substitution of raw rubber or raw rubber-containing compositions with elastomer-based powders or granules in existing value chains from a sustainability and cost perspective.

[0021] Illustrations

[0022] Figure 1 a shows a photograph of the material after attempted production of a compact from a powder of scrap tires according to Example 1 (comparative example).

[0023] Figure 1 b shows a photograph of the compact obtained according to Example 2 (comparative example) after falling from a height of 2 m.

[0024] Figure 1c shows a photograph of a compact obtained according to Example 3 according to the present invention, after being dropped from a height of 2 m.

[0025] Figure 1d shows a photograph of a compact obtained according to Example 4 according to the present invention, after being dropped from a height of 2 m.

[0026] Detailed description of the invention

[0027] As described above, the invention relates to compacts made from a crosslinkable material and a process for their production. To produce a compact from a crosslinkable material, according to the present invention, a mixture is provided as described above, which comprises, among other things, an elastomer-containing powder or granules. A "powder" or "granule" is understood here to mean a solid that is in the form of a large number of fine particles. The particles can typically move freely relative to one another when the powder or granules are agitated. The powder or granules used in the present invention are typically free-flowing. In the present description, a "granule" is distinguished from a powder by the dimensions of the particles. Accordingly, a "powder" is referred to herein when the particles have dimensions in the sub-millimeter range.A “granulate”, on the other hand, refers to particulate solids that contain larger particles with dimensions >1 mm. In the expert world, alternative terms such as “flour” (e.g. “rubber flour”) or “semolina” are sometimes used to describe powdered or granulated material. Irrespective of such alternative designations, such materials are also to be regarded as powders or granules within the meaning of the present disclosure and can be used as such. The powder or granules used according to the invention contain at least one elastomer. An “elastomer” is understood to mean an elastically deformable polymer material. Elastomers are therefore dimensionally stable but elastic and return to their original shape after deformation, i.e. they have rubber-elastic properties.Examples of elastomers that can be present in the powder or granules used according to the invention include elastomers obtainable by wide-mesh crosslinking (also referred to as vulcanization) of natural rubber or synthetic rubber, also referred to as rubber materials, and thermoplastic elastomers. The at least one elastomer can therefore comprise, for example, a crosslinked natural rubber, a crosslinked synthetic rubber, a thermoplastic elastomer, or a mixture or combination thereof. Natural rubber is obtained from the latex of the rubber tree (Hevea brasiliensis) and consists predominantly of cis-1,4-polyisoprene.Examples of synthetic rubbers include ethylene propylene diene rubbers (EPDM), styrene / diolefin rubbers such as styrene / butadiene rubber (SBR), polybutadiene rubber, polyisoprene, styrene / isoprene rubber, butadiene / isoprene rubber, butyl rubber such as isobutene / isoprene rubber, halobutyl rubber such as chloro- or bromobutyl rubber, nitrile rubber, hydrogenated nitrile rubber, carboxylated butadiene / acrylonitrile rubber, styrene / butadiene / acrylonitrile rubber, carboxylated styrene / butadiene rubber, silicone rubber, polychloroprene and epoxidized natural rubber. Examples of thermoplastic elastomers include thermoplastic polyamide elastomers, thermoplastic polyester elastomers, olefin-based thermoplastic elastomers such as PP / EPDM, thermoplastic styrene block copolymers, and urethane-based thermoplastic elastomers.

[0028] The powder or granules can contain the at least one elastomer in an amount corresponding to at least 30 wt.%, for example at least 35 wt.% or at least 40 wt.%, or at least 50 wt.%, based on the total weight of the powder or granules. The powder or granules can contain up to 100 wt.% of the at least one elastomer (ie, in the case of 100%, consist of it), for example 90 wt.% or less, 80 wt.% or less, 70 wt.% or less, or 60 wt.% or less, based on the total weight of the powder or granules. The proportion of the elastomer can be in a range spanned by any combination of the above-mentioned values, for example from 30 wt.% to 100 wt.%, or from 40 wt.% to 80 wt.%. Typically, the powder or granules contain at least 40 wt.%, such as 40 to 70 wt.%, of the at least one elastomer, based on the total weight of the powder or granules.

[0029] The powder or granules used according to the invention can preferably contain at least one recycled elastomer. "Recycled elastomer" is understood to mean an elastomer that has already been used in a product and is recovered from this product, typically at the end of its intended use. The recycled elastomer can, for example, comprise any of the above-mentioned elastomers or a mixture or combination thereof, for example in the amounts stated above. The product from which the recycled elastomer is obtained can be any elastomer-containing product or part or material thereof. Illustrative examples include, for example, old tires (such as car tires, truck tires, off-road tires) or parts thereof, such as tire treads or sidewalls, used conveyor belts, seals, shoe soles, or other elastomer products.The powder or granulate used according to the invention is preferably provided by a process for recycling old tires or parts thereof.

[0030] Waste tire materials and their recycling processes are summarized, for example, in K. Formela's "Sustainable development of waste tires recycling technologies - recent advances, challenges and future trends," Advanced Industrial and Engineering Polymer Research 4 (2021), pp. 209-222. To recycle waste tires, steel and fabric components are typically first removed. The waste tire (part) to be recycled is then subjected to coarse mechanical comminution by grinding, either at ambient temperature or cryogenically under nitrogen cooling, into a powder or granulate. Other processes utilize comminution using water jets.Powders and granules obtained from recycled tires (parts) (also known as ground tire rubber (GTR)) are commercially available from a variety of suppliers such as MRH GmbH, Genan GmbH or Roth International GmbH, at a fraction of the costs associated with the original production of corresponding elastomers.

[0031] As those skilled in the art are aware, powders or granules obtained from elastomer-containing products such as scrap tires through a recycling process may contain, in addition to the elastomer component, other components that are not or only partially separated from the elastomer component during the recycling process. These other components may include any ingredients commonly used in recycled products or materials alongside the elastomer component, for example, residues of the agents used to crosslink the elastomer, processing aids, and / or additives such as pigments or fillers. For example, powders or granules from the recycling of scrap tires usually contain significant amounts of fillers such as carbon black and / or silica, as well as residues of the agents used to crosslink the elastomer.The powder or granules may, for example, contain further constituents other than the elastomer component in an amount of up to 70 wt.%, such as 65 wt.% or less, or 60 wt.% or less, or 50 wt.% or less, based on the total weight of the powder or granules. The powder or granules may contain further constituents other than the elastomer component, for example in an amount of 10 wt.% or more, or 20 wt.% or more, or 30 wt.% or more, or 40 wt.% or more, based on the total weight of the powder or granules. The proportion of the further constituents other than the elastomer component, if present, may be within a range spanned by any combination of the above-mentioned values, for example from 10 wt.% to 70 wt.%, or from 20 wt.% to 60 wt.%.

[0032] The size of the particles in the powders or granules can be optionally adjusted. This can conveniently be carried out, for example, by fractionation by means of sieves using a successive arrangement of sieves with different mesh sizes. Particles with dimensions larger than a sieve opening defined by the mesh size are retained by the corresponding sieve, while particles with smaller dimensions pass through the corresponding sieve. The powders or granules used according to the invention can, for example, have a particle size of 5 mesh (4.0 mm) or less, or of 10 mesh (1.7 mm) or less, or of 16 mesh (1.0 mm) or less, or of 20 mesh (0.84 mm) or less, or of 24 mesh (0.71 mm) or less, or of 28 mesh (0.60 mm) or less, or of 32 mesh (0.50 mm).The powders or granules used according to the invention can, for example, have a particle size of 150 mesh (0.105 mm) or more, or of 115 mesh (0.125 mm) or more, or of 100 mesh (0.149 mm) or more, or of 80 mesh (0.18 mm) or more, or of 65 mesh (0.21 mm) or more, or of 60 mesh (0.25 mm) or more, or of 48 mesh (0.30 mm) or more, or of 42 mesh (0.35 mm) or more, or of 35 mesh (0.42 mm) or more. The powders or granules may have a particle size within a range defined by any combination of the above-mentioned values, for example from 150 mesh (0.105 mm) to 5 mesh (4.0 mm), or from 115 mesh (0.125 mm) to 20 mesh (0.84 mm), or from 65 mesh (0.21 mm) to 35 mesh (0.42 mm), or from 32 mesh (0.50 mm) to 10 mesh (1.7 mm). The above information refers to sieves of the Tyler Standard series (cf., for example, Chemiker-Kalender, HU von Vogel, Springer Verlag, 1956).

[0033] In the mixture provided according to the invention for producing the compacts, an elastomer-containing powder or granulate described in more detail above, or a mixture or combination of one or more elastomer-containing powders with one or more elastomer-containing granules, or a mixture or combination of two or more elastomer-containing powders or a mixture or combination of two or more elastomer-containing granules can be used.

[0034] The elastomer-containing powder and / or granules typically represent the quantitatively predominant component of the mixture. Thus, the mixture can contain the elastomer-containing powder and / or granules, for example, in an amount corresponding to 50 wt.% or more, or 60 wt.% or more, or 70 wt.% or more, or 75 wt.% or more, or 80 wt.% or more, or 85 wt.% or more, or 90 wt.% or more, based on the total weight of the mixture. The elastomer-containing powder and / or granules can, for example, be present in the mixture in an amount of 99 wt.% or less, or 95 wt.% or less, or 90 wt.% or less, or 85 wt.% or less, based on the total weight of the mixture. The proportion of the elastomer-containing powder and / or granules can be in a range spanned by any combination of the above-mentioned values, for example from 50 wt.% to 95 wt.%, or from 60 wt.% to 85 wt.%.

[0035] The mixture used to produce compacts from a crosslinkable material according to the present invention contains, in addition to the elastomer-containing powder or granules described above, one or more additives. The one or more additives comprise at least one binder.

[0036] The at least one binder is solid, ie it is in solid form under standard conditions (20°C, 101.3 kPa). The binder can be characterized by its thermal properties and, in particular, by a relatively low melting or softening temperature (T m). The binder has a melting or softening temperature of 100°C or less. The binder can, for example, have a melting or softening temperature of 90°C or less, or 80°C or less, or 70°C or less, or 60°C or less. The binder can, for example, have a melting or softening temperature of 20°C or more, or 30°C or more, or 35°C or more, or 40°C or more, or 45°C or more, or 50°C or more. The melting or softening temperature may be in a range spanned by any combination of the above-mentioned values, for example in the range from 30°C to 100°C, such as in the range from 40°C to 100°C, such as from 40°C to 90°C, or from 50°C to 80°C or from 50°C to 70°C.The binder preferably has a melting or softening temperature of 80°C or less, more preferably 70°C or less, approximately in the range from 30°C to 70°C. The melting temperature is the temperature at which a substance changes from a solid to a liquid state at atmospheric pressure (101.3 kPa). Softening temperature (also called glass transition temperature) is the temperature at which a substance (e.g. amorphous polymer) changes from a solid, glassy, ​​brittle state to a softened, flexible state at atmospheric pressure (101.3 kPa). The melting temperature of the binder can be determined by differential scanning calorimetry according to DIN EN ISO 11357-3, whereby the melting point after the second heating is usually taken as the measurement result, and a heating-cooling rate of 20°C / min is used. The softening temperature of the binder can be determined by differential scanning calorimetry according to DIN EN ISO 11357-2.Due to a relatively low melting or softening temperature, as described above, the binder can be converted into a soft and / or flowable state relatively easily by applying pressure and / or heating. The binder can thus be easily converted into a soft and / or flowable state, for example, before or during a mixing process to produce the mixture used according to the invention, which can promote dispersion, wetting, swelling, and activation of the elastomer-containing powders or granules. Where a transition occurs, it is generally reversible, so that the softened / flowable binder can be converted back into a solid state by reducing the pressure and / or cooling, and the binder can thus contribute to the strength and material cohesion of the pressed articles according to the invention.

[0037] Binders of a known type can be used according to the invention. The binder can, for example, comprise a thermoplastic polymer, a resin, an ionomer, a wax, or a mixture or combination thereof. Such binders can be produced in a known manner and are commercially available. Examples of thermoplastic polymers include ethylene-vinyl acetate (EVA) copolymers, polystyrene, polyesters such as polyethylene terephthalate, polycarbonates, polyamides, acrylic polymers, polyurethanes, diene-based polymers such as acryloyl-butadiene-styrene (ABS), polybutadienes, and liquid rubbers, and in particular polyolefins such as polyethylene, propylene, and copolymers based thereon. Examples of suitable resins include natural resins such as rosin, tall oil resins, or tall pitch. Ionomers can be produced by copolymerizing nonpolar or slightly polar monomers with monomers containing ionizable functional groups.The ionizable functional groups lead to ionic bonds between the polymer molecules. Examples of ionomers are commercially available under the trade names Surlyn® or Nucrel® from DuPont, or Eltex® from Ineos. Examples of waxes that can be used as binders include paraffinic waxes.

[0038] The one or more additives further comprise ethylenically unsaturated functional groups. The one or more additives therefore comprise at least one ethylenically unsaturated compound. “Ethylenically unsaturated” means herein that the functional groups or compounds specified thereby have one or more carbon-carbon multiple bonds, such as C=C double bonds and / or C=C triple bonds. The ethylenically unsaturated functional groups introduced with the additive component serve to enhance the crosslinkability of the material and can activate the particles of the elastomer-containing powder or granules against crosslinking and promote crosslinking, in particular by forming covalent bonds, between different particles of the elastomer-containing powder or granules. It is possible for the at least one binder to comprise one or more ethylenically unsaturated functional groups, i.e.Binder functionality and ethylenically unsaturated functional groups can be combined in one component. Alternatively, the at least one binder used contains no crosslinkable ethylenically unsaturated functional groups. In this case, one or more ethylenically unsaturated compounds are used in addition to the binder. These ethylenically unsaturated compounds can be, in particular, ethylenically unsaturated low-molecular-weight (molecular weight <500 g / mol) oligomers or monomeric organic compounds. Examples include substances that are typically used as monomers or reactive diluents, such as acrylates. However, within the scope of the present invention, preference is given to using a binder that itself comprises one or more ethylenically unsaturated functional groups, for example a binder of the types mentioned above containing one or more ethylenically unsaturated functional groups.

[0039] Particularly preferably, an ethylenically unsaturated binder of the polyalkenamer type can be used within the scope of the present invention. The at least one binder used can therefore comprise or consist of at least one polyalkenamer. The term "polyalkenamer" herein refers to polymers comprising a basic structure

[0040] -[(CH2)x-CH=CH]n- where x is an integer (typically in the range from 3 to 13) and n>2, usually n>10, frequently n>50. The polymers can be in open-chain form, in cyclic form, or as a mixture of open-chain and cyclic molecules. One or more hydrogen atoms of the basic structure can optionally be substituted by one or more organic groups, for example alkyl groups, or the basic structure can be unsubstituted. A polyalkenamer can introduce crosslinkable C=C double bonds into the mixture and also generally exhibits good chemical compatibility with conventional elastomer components. According to the invention, the binder can in particular comprise or consist of a poly-Cs-Cs-alkenamer.Examples of poly-Cs-Cis-alkenamers that can be used in the present invention include polypentenamer, polyhexenamer, polyheptenamer, polyoctenamer, poly(3-methyloctenamer), polydecenamer, poly(3-methyldecenamer), polydodecenamer, or mixtures and combinations thereof. Poly-Cs-Cis-alkenamers are obtainable by ring-opening metathesis polymerization of a corresponding cycloolefin, such as cyclopentene, cyclohexene, cycloheptene, cyclooctene, cyclodecene, cyclododecene, or substituted derivatives thereof. The ring-opening metathesis polymerization reaction is catalyzed by Ziegler-Natta catalysts such as halides or acetylacetonates of W, Mo, or Rh with AlEts or AlEtCh and an activator.

[0041] Polyalkenamers which can be used as binders according to the invention typically have a weight-average molecular weight (M w) of 10,000 g / mol or more, such as 20,000 g / mol or more, such as 50,000 g / mol or more, such as 80,000 g / mol or more, such as 100,000 g / mol or more. The polyalkenamer may, for example, have a weight-average molecular weight (M w ) of 300,000 g / mol or less, such as 250,000 g / mol or less, such as 200,000 g / mol or less, or 180,000 g / mol or less, or 150,000 g / mol or less. The weight-average molecular weight (M w ) of the polyalkenamer can be in a range spanned by any combination of the above-mentioned values, for example from 10,000 g / mol to 250,000 g / mol, preferably in the range from 80,000 to 180,000 g / mol. The weight-average molecular weight (M wThe molecular weight of the polyalkenamer can be determined by gel permeation chromatography (GPC) using polystyrene standards. The weight-average molecular weight of the polyalkenamer can be determined according to GPC using DIN 55672-1.

[0042] The polyalkenamer can be characterized by its thermal properties and, in particular, have a relatively low melting or softening temperature, as described above. Alternatively or additionally, the polyalkenamer can be characterized by its crystallinity content. For example, under standard conditions (20°C, 101.3 kPa), the polyalkenamer can have a crystallinity content of 20% or more, such as 25% or more, or 30% or more. The polyalkenamer can, for example, have a crystallinity content of 60% or less, such as 50% or less, such as 40% or less, such as 35% or less. The crystallinity content can be in a range spanned by any combination of the above-mentioned values, for example in the range from 20% to 50%, or from 25% to 35%. The crystallinity fraction of the polyalkenamer can be determined by differential scanning calorimetry according to DIN EN ISO 11357-7.The crystallinity of a polyalkenamer can also be determined using X-ray diffraction techniques, as described in Wenig, W., H.-W. Fiedel, and J. Petermann, "The Microstructure of Trans-Polyoctenamer." Colloid & Polymer Science 266, No. 3 (March 1988): 227-34.

[0043] According to the invention, a polyalkenamer or a mixture or combination of two or more polyalkenamers can be used as a binder. The binder used according to the invention preferably comprises or consists of a polyoctenamer. The polyoctenamer can in particular be a 1,8-polyoctenamer. The polyoctenamer can have a trans / cis double bond ratio of at least 60:40, preferably 70:30 or more, such as in the range from 75:25 to 90:10. The trans / cis double bond ratio can be determined by means of infrared spectroscopy (FT-IR), as described, for example, in Schneider, Wolfgang A., and Michael F. Müller. “Crystallinity and thermal behavior of trans-poly (1-octenylene).” Macromolecular Chemistry and Physics 189, No. 12 (1988): 2823-2837. Polyoctenamers with predominantly trans double bonds are also called trans-polyoctenamers. Polyoctenamers are commercially available from Evonik under the trade name Vestenamer®.

[0044] The one or more additives comprising the binder and the ethylenically unsaturated functional groups, such as the aforementioned polyalkenamer, are typically used in a total amount of 1 part by weight or more, based on 100 parts by weight of the elastomer-containing powder or granules. The one or more additives comprising the binder and the ethylenically unsaturated functional groups can, for example, be used in a total amount of preferably 2 parts by weight or more, 3 parts by weight or more, 4 parts by weight or more, 5 parts by weight or more, 8 parts by weight or more, or 10 parts by weight or more, based on 100 parts by weight of the elastomer-containing powder or granules.The one or more additives comprising the binder and the ethylenically unsaturated functional groups can be used, for example, in a total amount of 30 parts by weight or less, preferably 20 parts by weight or less, more preferably 18 parts by weight or less, even more preferably 15 parts by weight or less, based on 100 parts by weight of the elastomer-containing powder or granules. The polyalkenamer, as mentioned above, can form the binder. The at least one polyalkenamer can therefore be used in an amount that can be within the range of the amounts specified above.Thus, the at least one polyalkenamer can be used in a total amount of 1 part by weight or more, based on 100 parts by weight of the elastomer-containing powder or granules, for example in a total amount of preferably 2 parts by weight or more, 3 parts by weight or more, or 4 parts by weight or more, or 5 parts by weight or more, or 8 parts by weight or more, or 10 parts by weight or more, based on 100 parts by weight of the elastomer-containing powder or granules. The at least one polyalkenamer can be used, for example, in a total amount of 30 parts by weight or less, preferably 20 parts by weight or less, more preferably 18 parts by weight or less, even more preferably 15 parts by weight or less, based on 100 parts by weight of the elastomer-containing powder or granules. The total amount of the above-mentionedAdditives, such as polyalkenamer, can be in a range spanned by any combination of the above-mentioned values, for example in a range of 1 to 30 parts by weight, preferably 2 to 20 parts by weight, based on 100 parts by weight of the elastomer-containing powder or granules.

[0045] Optionally, the mixture used to produce compacts from a crosslinkable material according to the present invention may comprise one or more further components in addition to the elastomer-containing powder or granules and the one or more additives described above, which comprise the binder and the ethylenically unsaturated functional groups.

[0046] Thus, in the mixture used to produce compacts from a crosslinkable material according to the present invention, at least one polymer can optionally be further used which is different from the elastomer-containing powder or granules and the additives described above, which comprise the binder and the ethylenically unsaturated functional groups. The optional additional polymer can be, for example, a thermoplastic polymer such as a polyolefin, a polyester such as polyethylene terephthalate, a polyamide, polystyrene, polyvinyl chloride, or a mixture or combination thereof. Examples of suitable polyolefins include polyethylene, polypropylene, and copolymers based on ethylene and / or propylene, optionally with one or more other comonomer(s). The optional additional polymer is typically not an elastomer and / or is ethylenically saturated.The optional additional polymer preferably comprises or is a recycled polymer. Recycled polymers such as polyolefins are commercially available in large quantities at low cost. According to the invention, the use of the additional, preferably recycled polymer can be used to produce moldings containing polymer mixtures or blends, the properties of which can be adjusted within a wide range by selecting the relative amounts of the various polymers used. Thus, between 5 and 95 wt. %, such as between 20 and 80 wt. %, of the above-mentioned amount of elastomer-containing powder or granules in the mixture can be replaced by the optional additional polymer.

[0047] The material mixture from which the compacts according to the invention are produced contains crosslinkable groups, in particular ethylenically unsaturated groups. These can be crosslinked, for example, by exposure to actinic radiation, heating, and / or under the action of any residues of crosslinking-active substances contained in the elastomer-containing powder or granules in a step subsequent to the production of the compacts, as described in more detail below in connection with the further processing of the compacts. To promote this downstream crosslinking, one or more crosslinking agents can be deliberately added to the mixture used to produce the compacts. Suitable crosslinking agents include all substances by means of which the material mixture can be crosslinked to form a three-dimensional network.Crosslinking can occur in particular through chemical reactions involving ethylenically unsaturated functional groups, allowing covalent bonds to form between originally separate polymer molecules or particles, thus forming a three-dimensional network. Any crosslinking agents known from the prior art that are suitable for crosslinking ethylenically unsaturated polymers can thus be used as crosslinking agents. Conventional crosslinking systems, such as those described in F. Röthemeyer, F. Sommer, Kautschuk Technologie, 3rd ed., Hanser Verlag, 2013, are based on sulfur or sulfur-containing compounds, or on peroxides, and can be used in the context of the present invention. The at least one crosslinking agent can thus comprise, for example, one or more peroxides.Organic peroxides, in particular, can be used as peroxidic crosslinking agents. Examples of suitable organic peroxides include dicumyl peroxide, di-(2,4-dichlorobenzoyl) peroxide, tert-butyl peroxybenzoate, 1,1-di-(tert-butylperoxy)-3,3,5-trimethylcyclohexane, butyl 4,4-di-(tert-butylperoxy)valerate, di-(2-tert-butylperoxyisopropyl)benzene, tert-butylcumyl peroxide, 2,5-dimethyl-2,5-di-(tert-butylperoxy)hexane, di-tert-butyl peroxide, 2,5-dimethyl-2,5-di(tert-butylperoxy)hex-3-yne, or mixtures and combinations thereof. Such peroxidic crosslinking agents are commercially available from Pergan under the trade name Peroxan®. The at least one crosslinking agent may alternatively or additionally comprise sulfur and / or sulfur donors. Thus, elemental sulfur is preferably used as a crosslinking agent in the composition according to the invention.Elemental sulfur can be used in soluble or insoluble form, preferably in soluble form. Soluble sulfur refers to the yellow sulfur form (cyclooctasulfur, Ss, also known as α-sulfur), which is stable at ambient temperatures and highly soluble in CS2. Insoluble sulfur, on the other hand, refers to sulfur modifications that are barely soluble in CS2. In addition to or as an alternative to sulfur, one or more sulfur donors can be used as crosslinking agents. Examples of sulfur donors include dithioalkanes, dicaprolactam sulfides, polymeric polysulfides, sulfur-olefin adducts, or thiurams such as tetramethylthiuram disulfide, tetraethylthiuram disulfide, or dipentamethylenethiuram tetrasulfide. Sulfur can preferably be used as a crosslinking agent according to the invention.

[0048] The crosslinking agent, if used, is generally used in an amount effective for the crosslinking reaction. Typically, the crosslinking agent is used in an amount of 0.01 part by weight or more, such as 0.05 part by weight or more, or 0.1 part by weight or more, or 0.2 part by weight or more, or 0.3 part by weight or more, per part by weight of the above-described additive having ethylenically unsaturated functional groups. For example, the crosslinking agent may be used in an amount of 3 parts by weight or less, such as 2 parts by weight or less, or 1 part by weight or less, or 0.8 part by weight or less, or 0.5 part by weight or less, per part by weight of the above-described additive having ethylenically unsaturated functional groups.The crosslinking agent can be used, for example, in an amount within a range defined by any combination of the above-mentioned values, such as from 0.01 to 2 parts by weight, or from 0.03 to 1 part by weight, or from 0.1 to 0.5 parts by weight, per part by weight of the above-described additive having ethylenically unsaturated functional groups.

[0049] Optionally, one or more crosslinking agents can also be used in the mixture. The one or more crosslinking agents can, for example, comprise one or more components selected from accelerators, activators, dispersants, complexing agents, and retarders. Such crosslinking agents are described, for example, in F. Röthemeyer, F. Sommer, Kautschuk Technologie, 3rd ed., Hanser Verlag, 2013.

[0050] Examples of accelerators include xanthates, guanidines, dicarbamates, dithiocarbamates, thiurams, thiourea compounds, benzothiazolesulfonamides, aldehyde amines, amine derivatives such as tetramines, disulfides, thiazoles, sulfenamides, sulfenimides, piperazines, and amine carbamates. Examples of specific compounds that can be used as accelerators according to the invention are N-tert-butyl-2-benzothiazylsulfenamide, o-tolyl biguanidine (OTBG), 1,3-di-o-tolylguanidine (DOTG), α-cyclohexylbenzothiazole-2-sulfenamide (CBS), benzothiazyl-2-tert.-butylsulfenamid (TBBS), Benzo-thiazyl-2-dicyclohexylsulfenamid (DCBS), 1 ,3- Diethylthioharnstoff (DETU), 2-Mercaptobenzothiazol (MBT), Benzothiazyldicyclohexylsulfenamid (DCBS), 2-Mercaptobenzothiazoldisulfid (MBTS), Dimethyldiphenylthiuramdisulfid (MPTD), Ethylenthioharnstoff (ETU), Triethyltrimethyltriamin (TTT); N-t-Butyl-2-benzothiazol-sulfenimid (TBSI, 1 ,1'-Dithiobis(4-methylpiperazin), Hexamethylendiamincarbamat (HMDAC), Tetrabenzylthiuramdisulfid (TBZTD), Diethylthioharnstoff (DETU), N,N-Ethylen-thioharnstoff (ETU), Diphenylthioharnstoff (DPTU), Benzothiazyl-2-tert.-butylsulfenamid (TOBS), N,N'- Diethylthiocarbamyl-N'-cyclohexylsulfenamid (DETCS), Cyclohexylethylamin, Dibutylamin, Polyethylenpolyamine oder Polyethylenpolyimine wie z.B. Triethylentetramin (TETA).

[0051] The accelerator(s) are typically used in an amount corresponding to a weight ratio of accelerator to crosslinking agent in the range of 1:5 to 5:1, such as in the range of 1:4 to 4:1, or of 1:3 to 3:1 or of 1:2 to 2:1.

[0052] Zinc oxide, for example, can be used as an activator. A fatty acid or a salt thereof, for example stearic acid or a stearate such as zinc stearate, can also be used in the mixture. Such compounds can act, for example, as dispersants and complexing agents. Preferably, a crosslinking system containing sulfur, one or more accelerators, zinc oxide, and a fatty acid or a salt thereof, such as stearic acid, can be used in the mixture for producing the pellets according to the invention.

[0053] Activators such as zinc oxide are typically used in an amount corresponding to a weight ratio of activator to crosslinking agent in the range of 1:4 to 8:1, such as in the range of 1:3 to 5:1, or 1:2 to 4:1, or 1:1 to 3:1.

[0054] Fatty acid or salts thereof, such as stearic acid or stearate, are typically used in an amount corresponding to a weight ratio of fatty acid / salt to crosslinking agent in the range of 1:10 to 10:1, such as in the range of 1:8 to 8:1.

[0055] Optionally, the mixture used to produce compacts from a crosslinkable material according to the present invention may additionally contain, depending on the need and application, one or more further components such as are commonly used in the field of elastomer compositions, such as fillers, pigments, dyes, plasticizers, processing aids such as oils, mold release agents, flame retardants, anti-aging, UV or ozone protection agents, and adhesives. If used, such optional components are used in amounts suitable to achieve the respective intended use. Suitable amounts can be determined by the person skilled in the art through standard experiments. The mixture used to produce the compacts according to the invention can be produced cost-effectively and efficiently using conventional techniques and equipment from the powder processing field.Thus, the elastomer-containing powder or granules, the one or more additives comprising the binder and the ethylenically unsaturated groups, and any further optional components, in suitable amounts as described above, can be mixed in a mixer with homogenization to form an appropriate mixture. The mixer used can be, for example, a conventional powder mixer or, preferably, a high-speed mixer such as a Henschel blender, speed mixer, or fluid mixer. Mixing can be based, for example, on the method described in EP 0 508 056 B1 or in Diedrich, KM, and BJ Burns, "Possibilities of ground tire recycling with trans-polyoctenamer." Gummi, Fasern, Kunststoffe 53, No. 3 (2000): 178-183. The production of the mixture using powder mixing technology is generally more cost-effective than the production of comparable mixtures based on raw rubber.In terms of investment and operating costs, powder mixers are generally significantly cheaper than the roller mixers or internal mixers commonly used for processing raw rubber-based compositions.

[0056] Furthermore, the compacts made from the crosslinkable material produced according to the invention can also be reused to prepare a starting mixture described above. Thus, one or more compacts comprising at least the elastomer-containing powder or granules and the one or more additives comprising the binder and the ethylenically unsaturated groups, as well as any other optional components, can be comminuted, for example using a mill or other mechanical comminution device, and used to produce the mixture as described above. In this way, for example, compacts that arise as rejects, such as those rejected in a quality control step, can be effectively recycled in the process according to the invention.

[0057] The components contained in the provided mixture, such as the elastomer-containing powder or granules, the one or more additives comprising the binder and the ethylenically unsaturated groups, and any other optional components such as a crosslinking agent, are generally physically mixed with one another, for example in the form of a blend, but are not connected by solid chemical bonds, such as covalent bonds. Due to the content of crosslinkable functional groups, particularly ethylenically unsaturated functional groups, the material mixture is crosslinkable. The resulting mixture is usually flowable or pourable.

[0058] The provided mixture typically has a bulk density of less than 1.0 g / cm 3 , for example 0.9 g / cm 3 or less, of 0.8 g / cm 3 or less, or 0.7 g / cm 3 or less, or 0.6 g / cm 3or less. For example, the mixture may have a bulk density of 0.1 g / cm 3 or more, or 0.2 g / cm 3 or more, or 0.3 g / cm 3 or more, or 0.4 g / cm 3 or more. The mixture may have a bulk density that lies within a range spanned by any combination of the above-mentioned values, for example from 0.1 g / cm 3 up to 1.0 g / cm 3 , or 0.2 g / cm 3 up to 0.8 g / cm 3 , or 0.3 g / cm 3 up to 0.7 g / cm 3 . The bulk density can be determined, for example, according to DIN ISO 697.

[0059] According to the invention, the crosslinkable material mixtures described above can be used to produce pellets which consist of a corresponding crosslinkable material and can have a significantly higher density than the bulk density of the starting mixture.

[0060] The provided, optionally heated mixture is compacted into a compact using a shaping tool. Compaction into a compact using a shaping tool can be carried out using pressure or negative pressure (vacuum). Compaction generally takes place after the mixture has been provided, using a shaping tool provided for this purpose and under controlled conditions. Through compaction, a shaped body with a defined shape determined by the shaping tool is generally formed as a compact. Any compaction of the mixture that may occur during mixing, for example in a mixer, must therefore be distinguished from this and does not usually lead to the formation of a compact.

[0061] The type, shape, and dimensions of the forming tool used in the process according to the invention for producing the compacts are not limited. Any forming tools known per se from the prior art and suitable for producing compacts can be used according to the invention. Shaping and / or compacting can be carried out, for example, discontinuously or continuously, for example by compression molding or extrusion. Compacting can be carried out, for example, in a mold using pressure.

[0062] The mixture used is generally compacted by a compression factor > 1. The compression factor indicates the ratio of the geometric density (D g ) of the material used in the pressurized forming tool to the bulk density (D s ) of the starting mixture. If a given amount of a starting mixture with a bulk density (D s) and an initial volume (V s ) in a mold to a certain volume (V g ) is compressed, the geometric density (D g) of the material used in the pressurised shaping tool is calculated and the corresponding compression factor is stated. The mixture used in the process according to the invention can be compressed, for example, by a compression factor of at least 1.2, or of at least 1.3, or of at least 1.4, or of at least 1.5, or of at least 1.6, or of at least 1.7, or of at least 1.8, or of at least 2.0. The mixture used can be compressed, for example, by a compression factor of 4.0 or less, or of 3.5 or less, or of 3.0 or less, or of 2.5 or less. The mixture can be compressed according to a compression factor which lies in a range spanned by any combination of the above-mentioned values, for example in the range from 1.2 to 3.5 or from 1.8 to 4.0 or from 2.0 to 3.0.Preferably, the material mixture used in the process according to the invention is compressed by a compression factor of at least 1.4, particularly preferably at least 1.8 or at least 2.0. This allows particularly advantageous properties of the compact to be achieved, such as good material cohesion and high strength and density.

[0063] According to the invention, compaction can be carried out in particular using pressure. The pressure exerted in the compaction process according to the invention can vary depending on the shaping tool used, the material, and the desired degree of compaction. The pressure can generally be selected such that compaction occurs by a compression factor, as described above. The applied pressure can, for example, be in a range from 0.1 MPa to 20 MPa, for example in a range from 0.3 MPa to 10 MPa or from 0.5 MPa to 5 MPa. As described above, compaction can also be carried out by applying negative pressure (vacuum), for example at 0.05 MPa to 0.1 MPa.

[0064] Compaction is typically carried out for a duration that is sufficiently long to achieve the desired compaction and consolidation of the material mix, while at the same time being as short as possible to take economic factors into account. The compaction duration can therefore vary widely, from a few seconds to several hours. For example, the compaction duration can be at least 10 seconds, such as at least 20 seconds, such as at least 30 seconds, or at least 1 minute, or at least 5 minutes. The compaction of the material mix can be carried out for a period of 120 minutes or less, such as 90 minutes or less, 60 minutes or less, or 40 minutes or less, or 30 minutes or less, or 20 minutes or less, or 10 minutes or less.

[0065] The mixture may be compacted for a duration within a range defined by any combination of the above-mentioned values, for example within a range of 10 seconds to 120 minutes, or from 20 seconds to 90 minutes, or from 30 seconds to 30 minutes.

[0066] As already mentioned above, the mixture that is compacted into a pellet is heated. Heating of the mixture can take place before and / or during compaction. For example, the mixture can be heated before it is introduced into the shaping tool, for example during the production of the mixture as described above. For example, the mixture can be heated during the mixing process, for example by the frictional heat generated and / or by external heat supply, for example via a heating device of the mixer used. Additionally or alternatively, the mixture can be heated after the mixing process, for example in a temperature-controlled storage container or in an oven. Additionally or alternatively, the mixture can be heated after it is introduced into the shaping tool, for example by means of a heatable mold.Furthermore, heating by irradiation, for example by means of microwave radiation or infrared radiation, is also possible.

[0067] By heating the material mixture, advantageous properties of the compact can be achieved in terms of good material cohesion and high strength and density.

[0068] The mixture used, which is compacted to form a pellet, is preferably heated in the process according to the invention to a temperature approximately in the range of the melting or softening temperature (T m ) of the binder or polyalkenamer or above. This allows the mixture to reach a temperature greater than or equal to (T m -10 K), such as to a temperature greater than or equal to (T m -5 K), or to a temperature greater than or equal to T m , or to a temperature greater than or equal to (T m +5 K), or to a temperature greater than or equal to (T m+10 K). The mixture can, for example, be heated to a temperature less than or equal to (Tm+50 K), such as to a temperature less than or equal to (T m +40 K), to a temperature less than or equal to (T m +30 K), or to a temperature less than or equal to (T m +20 K). The material mixture can be heated to a temperature within a range spanned by any combination of the above-mentioned values, for example in the range of (T m -10 K) to (T m +50 K), or in the range of T m are m+40 K). However, the mixture is not heated to temperatures of 120°C or more. The mixture that is compacted into a pellet is therefore generally heated to a temperature of <120°C. A mixture temperature of less than 120°C makes it possible to avoid crosslinking reactions during pellet production to a significant extent, thus preserving the formability and crosslinkability of the material. The mixture that is compacted into a pellet can, for example, be heated to a temperature in the range of T mto <120°C or from 40°C to 120°C. The mixture can be heated to a temperature of approximately 45°C or more, 50°C or more, 55°C or more, 60°C or more, 65°C or more, or 70°C or more. The mixture that is compacted into a pellet can be heated to a temperature of approximately 115°C or less, such as 110°C or less, 105°C or less, 100°C or less, 95°C or less, or 90°C or less. The mixture that is compacted into a pellet can be heated to a temperature in a range resulting from a combination of the above values, for example in the range of T m to 110°C, or from 60 to 110°C, or from (T m+10 K) to 100°C, or from 70°C to 100°C. Compaction in the process according to the invention can be carried out in particular under conditions under which the binder is moldable and / or flowable. For example, a binder which is in solid form under standard conditions can be compacted by applying pressure and heating to a temperature higher than ambient temperature, for example, as described above in the range of the melting or softening temperature (T m ) of the binder or above, into a soft and / or flowable state, and thus effectively fill cavities during compression, penetrate between particles of the elastomer-containing powder or granules and wet them, swell them, bind them together and / or activate them for crosslinking.

[0069] After the material has been compacted, the formed compact is demolded. The compact can then be removed from the forming tool. Demolding generally occurs after reducing the pressure applied for compression, especially at ambient pressure, for example, after opening the mold or passing through the extruder outlet. Demolding involves releasing the formed compact from the forming tool. This can be done manually or mechanically, for example. Demolding can include, for example, releasing by impact, tapping, gripping, applying positive or negative pressure, punching, cutting, or a combination thereof. Optionally, a mold release agent can also be used.

[0070] The mixture, which was heated to compact the compact, is cooled before demolding. The mixture is cooled to a temperature below the melting or softening temperature (T m) of the binder. This allows the softened / flowable binder or polyalkenamer to return to a more rigid and / or solid state, thus contributing to the strength and good material cohesion of the formed compact. For example, demolding of the compact can be carried out at a temperature of less than or equal to (T m -5 K), or a temperature less than or equal to (T m -10 K), or a temperature less than or equal to (T m -20 K). The demolding of the compact can, for example, take place at a temperature of 10°C or more, such as 15°C or more, or 20°C or more, or 25°C or more. The demolding of the compact can take place at a temperature that lies within a range spanned by any combination of the above-mentioned values, for example in the range from ambient temperature (such as 10-25°C) to <T m , such as from 10°C to <T m, or from 15°C to (T m -5 K). Demolding is typically carried out at a temperature of less than 60°C, such as less than 40°C, for example in the range of 10°C to 40°C, such as approximately ambient temperature.

[0071] The compacts obtainable by the process according to the invention consist of a crosslinkable material defined by the material mixture used to produce the compact. The resulting compacts may still comprise at least 70%, preferably at least 90%, or essentially all of the crosslinkable ethylenically unsaturated functional groups present in the originally prepared material mixture used to produce the respective compact. As such, they can be further processed, as described in more detail below, into crosslinked elastomer compositions and molded articles formed therefrom. The compacts may have a ready-to-use composition that can be effectively processed into crosslinked elastomer compositions and molded articles formed therefrom without the need to add further components.

[0072] The pellets produced according to the invention can have a significantly higher density than the bulk density of the starting mixture. For example, the pellets can have a geometric density which is a factor of 1.2 or more, or of 1.3 or more, or of 1.4 or more, or of 1.5 or more, or of 1.6 or more, or of 1.7 or more, or of 1.8 or more, or of 2.0 or more, or of 2.5 or more greater than the bulk density of the material mixture used to produce the respective pellet. The pellets can, for example, have a geometric density which is a factor of up to 5.0, such as up to 4.0, or up to 3.5, or up to 3.0 greater than the bulk density of the material mixture used to produce the respective pellet.The compacts can have a geometric density which is a factor greater than the bulk density of the material mixture used to produce the respective compact, which lies in a range spanned by any combination of the above-mentioned values, for example by a factor in the range from 1.2 to 5.0, such as in the range from 1.5 to 4.0, or from 1.8 to 3.0. They therefore make it possible to convert elastomer-containing powders or granules, such as those based on recycled elastomers, e.g. obtained from old tires, into a form with a significantly higher density that is easy to handle and can be further processed. The compacts can have a density which comes close to the theoretical density of the corresponding cross-linked material.The compacts produced according to the invention can, for example, have a geometric density that corresponds to 20% or more, preferably 50% or more, more preferably 70% or more, even more preferably 80% or more, or 90% or more, of the theoretical density of the corresponding crosslinked material. The compacts according to the invention can thus be stored, transported, and further processed in a space- and cost-saving manner. Due to the relatively high density, further processing of the compacts is generally possible using conventional shaping tools, such as those used for processing raw rubber-based feedstocks, without the need for specially manufactured tools with larger filling volumes, as is regularly the case with the direct processing of elastomer-containing powders or granules into crosslinked elastomer compositions and molded articles formed therefrom.The pellets produced according to the invention are also easier and cleaner to handle than powders or granules, and can be handled using common means such as grippers or conveyor belts used to handle rubber blanks. The production of the pellets based on powder mixing technology is significantly more cost-effective than the production of comparable mixtures based on raw rubber. The pellets according to the invention are therefore very well suited for substituting raw rubber or raw rubber-containing compositions in existing production processes. The strength and material cohesion of the pellets can be adjusted by selecting the process conditions, as illustrated in the examples. Consolidated pellets of high strength and good material cohesion can be produced according to the invention.

[0073] Furthermore, as mentioned above, the resulting pellets can be recycled into the process according to the invention and reused in the step of providing a mixture for producing pellets. This allows pellets that are rejected, such as those rejected in a quality control step, to be reused in the process according to the invention, thus increasing the economic efficiency of the process.

[0074] Using the process according to the invention, compacts made from a crosslinkable material can be produced in a wide variety of shapes and dimensions. The shape and dimensions can be determined by the choice of the forming tool used to produce the compact. Possible shapes range from simple shapes such as cuboids, cubes, blocks, plates, sheets, strands, pellets, spheres, or cylinders to complex geometric shapes. The compacts typically have a length in the direction of maximum extension (maximum length) of less than or equal to 200 cm, such as less than or equal to 100 cm, or less than or equal to 50 cm, or less than or equal to 30 cm, or less than or equal to 10 cm. The compacts can, for example, have a length in the direction of maximum extension (maximum length) of 1 cm or more, such as 2 cm or more, or 5 cm or more, or 10 cm or more.The pellets may have a maximum length that lies within a range defined by any combination of the above-mentioned values, for example, in the range from 1 cm to 200 cm, or from 2 cm to 30 cm. The pellets according to the invention may have a volume of less than or equal to 1,000 cm. 3 such as less than or equal to 500 cm 3 , less than or equal to 200 cm 3 , less than or equal to 100 cm 3 , less than or equal to 50 cm 3 , or less than or equal to 20 cm 3 , or less than or equal to 10 cm 3 . The pellets according to the invention can, for example, have a volume of 1 cm 3 or more, such as 2 cm 3 or more, or 5 cm 3 or more, or 10 cm 3 or more, or 20 cm 3 or more, or 50 cm 3or more. The pellets may have a volume that lies within a range defined by any combination of the above-mentioned values, for example in the range of 1 cm 3 up to 1,000 cm 3 , such as in the range of 10 cm 3 up to 200 cm 3 However, according to the invention, pellets with larger dimensions are also possible, for example with volumes of 10,000 cm 3 or more, or 0.1 m 3 or more or of 1 m 3 or more, and / or maximum lengths of more than 2 m, such as 3 m or more, or 5 m or more, or 10 m or more. For example, compacts of any length can be produced by extrusion. These can be stored, for example, in the form of a roll, coil, spindle, or a layered or layered structure (such as a wigwag sheet). The stored compact, e.g., rolled up, can be removed again as needed, e.g., unrolled, and divided.

[0075] It can be provided that the compact is pre-portioned. For example, compacts can be designed with defined, predetermined portions (e.g., specific masses) to facilitate packaging and dosing. For example, a compact according to the invention can have one or more predetermined breaking points. The predetermined breaking points can enable easy division of the compact into several equal or different-sized parts. The predetermined breaking points can be formed, for example, in the form of tapered portions, webs, perforations, or other connecting elements that can be separated mechanically relatively easily.

[0076] Elastomer compositions and molded articles formed therefrom can be produced from the above-described inventive compacts made of a crosslinkable material. "Elastomer composition" herein refers to a dimensionally stable, elastomer-containing material with rubber-elastic properties. Elastomer compositions can be produced by crosslinking (also referred to as vulcanizing) the crosslinkable material described herein. Crosslinking can be achieved, for example, by irradiation with actinic radiation and / or heating to a temperature at which a chemical crosslinking reaction takes place in the composition. The chemical crosslinking reactions can create links via covalent bonds between originally separate molecules, thus forming a three-dimensional network.In this case, crosslinking can occur in particular through a chemical reaction involving ethylenically unsaturated functional groups, which can be present both in the additive component, for example in the binder, in particular the polyalkenamer, and in the (activated) elastomer-containing powder or granules, for example under the action of a crosslinking agent, for example by forming sulfur bridges. This can result in the formation of a wide-meshed three-dimensional network, which imparts rubber-elastic properties to the resulting crosslinked material. In the elastomer composition obtainable from the crosslinkable material, the additive component and the elastomer-containing powder or granules can thus be crosslinked with one another. The particles of the powder or granules are thus generally firmly embedded in the elastomer composition.

[0077] From the compacts according to the invention themselves, molded articles made of a crosslinked elastomer composition can be produced directly, without the need for further shaping. For this purpose, a compact made of a crosslinkable material is provided as described above, and the crosslinkable material is then crosslinked to form a crosslinked elastomer composition. This procedure can be used in particular when the compacts already have the desired final shape.

[0078] However, the compacts can also be used in the molding production of elastomer-based molded articles. In this case, a feed material for a molding tool can be provided, which comprises at least one compact according to the invention made of a crosslinkable material or one or more parts thereof. The at least one compact can be comminuted or divided for this purpose if necessary. In addition to the compact according to the invention, the feed material can optionally comprise further components, for example binders and / or processing aids such as mold release agents, and / or reinforcing fabrics or fibers. The feed material is then shaped into a desired shape using the molding tool, and the feed material is crosslinked to form a crosslinked elastomer composition. Shaping by means of the molding tool can take place before, during and / or after crosslinking, preferably before and / or during crosslinking.For crosslinking and shaping the compositions according to the invention, conventional processing techniques and tools, such as those known to those skilled in the art from the field of processing rubber compositions and described, for example, in F. Röthemeyer, F. Sommer, Kautschuk Technologie, 3rd ed., Hanser Verlag, 2013, can be used. As described above, the compacts according to the invention advantageously enable, in particular, the use of shaping tools such as those otherwise used for processing raw rubber-based feedstocks. Shaping can be carried out, for example, by compression molding, extrusion, or injection molding.

[0079] The crosslinking can, regardless of whether shaping takes place or not, take place in particular at a temperature greater than 120°C, such as 140°C or more, such as 150°C or more, such as 160°C or more. The crosslinking can be carried out, for example, at a temperature of 250°C or less, such as 220°C or less, such as 200°C or less, such as 180°C or less. The crosslinkable material can be crosslinked, for example, at a temperature which lies in a range spanned by any combination of the above-mentioned values, for example from 120°C to 250°C, or from 140°C to 220°C. The crosslinking is preferably carried out at a temperature in the range from 140°C to 200°C.

[0080] The crosslinking time depends on the crosslinking temperature used and the dimensions of the amount of material to be crosslinked. Crosslinking is generally carried out in a time of 60 minutes or less, for example in a time of 30 minutes or less, or 20 minutes or less, or 15 minutes or less, or 10 minutes or less, or 5 minutes or less. Crosslinking can, for example, take place in a time of 10 seconds or more, such as 15 seconds or more, such as 30 seconds or more, such as 1 minute or more, such as 2 minutes or more, such as 5 minutes or more. The crosslinkable material can be crosslinked for a time that lies within a range spanned by any combination of the above-mentioned values, for example for a time in the range of 10 seconds to 60 minutes, such as in the range of 2 to 30 minutes.Typically, the curing time ranges from 1 to 20 minutes. Low curing temperatures and large dimensions of the material to be cured tend to require longer curing times.

[0081] The compacts according to the invention can be used to produce molded articles of a wide variety of shapes and dimensions. The molded articles produced can be used in their own right or, after further processing and / or as parts in products, can be used. Thus, the compacts according to the invention can be used to manufacture any conventional product in the rubber processing industry, for example, tires or tire components, cable sheathing, tubes, mats, coverings, conveyor belts, drive belts, rollers, coatings, hoses, dampers, protective elements, shoe soles, balls, sealing elements, or profiles, and containers of all kinds, such as cups, pots, and buckets.

[0082] The elastomer compositions obtainable from the compacts according to the invention and the molded articles formed therefrom can have good material cohesion and good mechanical properties, which can also meet more demanding applications.

[0083] However, the pellets according to the invention are generally excellently suited for substituting raw rubber or raw rubber-containing compositions in existing production processes.

[0084] The present invention is illustrated below with some specific examples. These examples are exemplary and illustrative. They are not to be considered limiting the invention, which rather extends to the full extent set forth in the general description and the following claims, including equivalents.

[0085] Examples

[0086] Production of material mixtures (Examples 1-6)

[0087] Various material mixtures based on elastomer-containing powder from ground tire rubber (GTR) were prepared. For this purpose, the starting materials listed in Table 1 were mixed in the specified quantities in a Hauschild SpeedMixer DAC 400 mixer (Hauschild GmbH & Co KG, Germany) at high mixing speed (1,800 rpm) to form a homogeneous material mixture. During the mixing process, the material mixture was heated to a temperature of 85°C ± 5°C. The temperature was determined using an infrared thermometer (Bosch UniversalTemp).

[0088] The quantities of the individual components are given in Table 1 as parts by weight based on 100 parts by weight of the powder from used tires (parts per hundred rubber component, abbreviated to “phr”).

[0089] Table 1 :

[0090] *: Comparison example

[0091] 1 : Powder from used tires (ground tire rubber, GTR), particle size <425 pm, commercially available from Genan GmbH

[0092] 2: Polyoctenamer, commercially available from Evonik under the trade name Vestenamer®, T m :

[0093] 54°C

[0094] 3: Vivatec 500, commercially available from Hansen & Rosenthal

[0095] 4: Ground sulfur, commercially available from Avokal

[0096] 5: Zinc oxide, purest, commercially available from Dr. Wieland GmbH & Co. KG

[0097] 6: commercially available from Calcic

[0098] 7: A / -Cyclohexylbenzothiazole-2-sulfenamide, vulcanization accelerator, commercially available from Lanxess

[0099] 8: Tetrabenzylthiuram disulfide, vulcanization accelerator, commercially available from Richon. The resulting mixtures were powdery and free-flowing. The bulk density of the material mixtures was determined by weighing 100 g of each material mixture, pouring the weighed amount of the material mixture into a cylindrical measuring cup (diameter: 10 cm), and reading the volume occupied by the material mixture in the measuring cup. The bulk densities, determined as the quotient of the determined respective volume to the applied weight of the material mixture, are given in Table 1.

[0100] Production of pellets (Examples 1-6)

[0101] From the material mixtures prepared in Examples 1-6, compacts were produced by compression molding (using an unheated mold). For this purpose, 100 g of the respective heated (T: 85°C ± 5°C) material mixture was placed into a cylindrical cavity (diameter: 7 cm) of an unheated mold made of ASA plastic (ASA Extrafill from Fillamentum) and then compacted using a pressure die of a press (Lauffer RLKV 25 / 1) that positively engaged the cavity from above. For this purpose, the pressure die was positioned by the press at a distance (h) of 26 mm between the flat surface of the pressure die that came into contact with the material mixture and the planar bottom surface of the cylindrical cavity. The applied pressure was estimated to be in the range of 0.5-3 MPa. After approx.After 90 minutes of compression, the mold was opened by removing the plunger from the cavity, and the resulting cylindrical compact was then manually removed from the cavity. The temperature of the compact was measured immediately before demolding using an infrared thermometer (Bosch UniversalTemp) and was 30°C ± 5°C in each case.

[0102] The resulting compacts were examined and qualitatively evaluated for their strength and material cohesion. For this purpose, the compacts were dropped from a height of 2 meters onto a concrete floor. Furthermore, the material cohesion was examined when pressure was applied manually. The evaluation was performed on a scale of 0-5, with:

[0103] 0: no material cohesion (no consolidated compact formed)

[0104] 1 : low material cohesion (fragile compact, under low manual

[0105] destroyed by force or fall)

[0106] 2: moderate material cohesion (compact largely destroyed under manual force or by falling)

[0107] 3: moderate to good material cohesion (compact largely withstands manual force, damage from falling)

[0108] 4: good material cohesion (compact withstands manual force, hardly

[0109] Damage from falling) 5: very good material cohesion (compressed part withstands manual force, no / minimal damage from falling)

[0110] In addition, the density of the pellets obtained was determined as geometric density (D g ) is determined from the quantity of compacted material mixture used and the volume determined from the dimensions (diameter, height) of the respective cylindrical compact measured using a caliper.

[0111] The determined properties of the pellets produced from the various material mixtures used are summarized in Table 2 below. The ratio of the geometric density (D g ) of the respective pellet obtained and the bulk density (D s ) of the material mixture used for its production is also given in Table 2.

[0112] Table 2:

[0113] *: Comparison example

[0114] The powder from scrap tires alone does not produce a consolidated compact (Example 1). As can be seen from Figure 1a, the material used was still in powder form even after the pressing process. Although compacts can be produced from the powder from scrap tires alone with a significantly longer compression time (> 6 h), these are of insufficient quality and have low material cohesion and low strength, so that they fall apart even under the application of small forces. By adding a process oil to the powder from scrap tires, a consolidated compact can be produced; however, the density and material cohesion remain low (see Example 2), but the compact still has relatively low strength and is easily destroyed by falling (see Figure 1b).Furthermore, the compacts produced in this way exhibit hardly any crosslinking functionality and therefore cannot be effectively crosslinked to form consolidated elastomer masses. In contrast, compacts produced according to the invention (cf. Examples 3-6) in which the elastomer-containing particles are effectively held together by a binder and exhibit the additional crosslinking functionality, so that they can subsequently be effectively processed into consolidated crosslinked elastomer masses and molded articles formed therefrom. As can be seen from Table 2, even comparatively small relative amounts of the binder used result in a good material cohesion and a consolidated, solid compact (cf. Example 3), which, as illustrated in Figure 1c, largely withstands manual force and, although partially damaged if dropped, remains fundamentally intact.By adding process oil, crosslinking agents, and additives, the material cohesion, strength, and density of the compact can be further increased (see Example 4). The use of larger amounts of binder further increases the strength and density of the compact (see Example 5). Consolidated compacts with high strength, excellent material cohesion, and high density are obtained. As shown in Figure 1d for Example 4, these compacts withstand manual force and are hardly or not at all damaged by drops. However, the use of particularly large amounts of process oil can reduce the strength and material cohesion (see Example 6).

[0115] Thus, according to the invention, ready-to-use, easy-to-handle compacts can be provided which can be further processed effectively using tools conventionally used for shaping and crosslinking raw rubber-based compositions.

[0116] Variation of process parameters a) Temperature of the material mixture (Examples 4 and 7-9)

[0117] As described above, compacts were produced from the material mixture of Example 4 by compression molding (using an unheated mold). The material mixture filled into the cylindrical cavity of the mold had a different temperature T in each case, namely a) 85°C ± 5°C (Example 4), b) 65°C ± 5°C (Example 7), c) 50°C ± 5°C (Example 8), or d) 30°C ± 5°C (Example 9). The different temperatures of the material mixture were adjusted by varying the mixing time, with shorter mixing times leading to lower temperatures due to the shorter duration of heating frictional forces. In the case of Examples 4, 7, and 8, the compression time was approximately 90 minutes, and in the case of Example 9, approximately 6 hours.

[0118] The resulting compacts were tested for strength, cohesion, and density as described above. The results are summarized in Table 3. Table 3:

[0119] *: Comparison example

[0120] Even at temperatures below the melting temperature of the binder used (54°C), compacts were consistently obtained which exhibit crosslinking functionality and can subsequently be effectively processed into consolidated crosslinked elastomer compositions and molded articles formed therefrom. However, without heating the mixture (T: 30°C ± 5°C), the material cohesion, strength, and density of the compact were low (Example 9). In contrast, compacts with good material cohesion and high strength and density were achieved when the material mixture was heated to temperatures in the range of the melting temperature of the binder used (cf. Example 8), or preferably above (cf. Examples 4 and 7). Thus, pressing can be carried out using a mixture heated to a temperature of 50°C or more, preferably approximately 60°C or more, or 80°C or more.At temperatures close to or above the melting temperature of the binder used, the binder liquefies and can thus fill voids between the elastomer-containing particles, effectively wetting, swelling, and bonding the particles together. b) Compression time, demolding temperature (Examples 4 and 10-12).

[0121] From the material mixture of Example 4, compacts were produced by compression molding (with an unheated mold) as described above in connection with Examples 1-6, whereby the compression time, and thus the time available for natural cooling of the material mixture in the mold, was varied as shown in Table 4 below. This varied the temperature measured before demolding, which is also shown in Table 4.

[0122] The compacts, where consolidated compacts were obtained, were tested for strength, material cohesion, and density as described above. The results are also summarized in Table 4. Table 4:

[0123] *: Comparison example

[0124] In the case of Examples 11 and 12, in which demolding took place at temperatures of 65°C and 85°C, respectively, significantly above the melting point of the binder (54°C), no consolidated compact was obtained. After the pressing process, a powder remained whose state remained essentially unchanged by compression. As can be seen from Table 4, however, when demolding took place at lower temperatures, such as below 60°C, consolidated compacts according to the invention made of a crosslinkable material were obtained (cf. Examples 4 and 10). This indicates that if the material mixture used is heated to a temperature at which the binder liquefies for pressing, as in these examples, cooling to a lower temperature before demolding may be expedient so that the binder can solidify again to form sufficient cohesion between the elastomer-containing particles.Particularly advantageous properties of the compact in terms of good material cohesion and high strength and density were achieved particularly at demoulding temperatures below the melting point of the binder used (cf. Example 4), such as at ambient temperature.

[0125] c) Compression factor (examples 4 and 13-15)

[0126] From the material mixture of Example 4, compacts were produced by compression molding (with an unheated mold) as described above in connection with Examples 1-6, wherein the material mixture was compressed by a compression factor which was adjusted differently in each case by varying the distance (h) of the flat stamping surface of the pressure stamp coming into contact with the material mixture to the planar bottom surface of the cylindrical cavity and was a) 26 mm (Example 4), b) 39 mm (Example 13), c) 52 mm (Example 14) or d) 65 mm (Example 15).

[0127] The resulting compacts were tested for strength, cohesion, and density as described above. The results are summarized in Table 5.

[0128] Table 5:

[0129] As Example 15 illustrates, it is possible according to the invention to produce compacts from a crosslinkable material even with a comparatively low compression factor of slightly greater than 1.0. Nevertheless, the material cohesion, strength and density of the compact were then low. With a larger compression factor, however, compacts with increasingly greater material cohesion and greater strength and density were obtained (cf. Examples 4, 13 and 14). Particularly advantageous properties of the compact in terms of good material cohesion and high strength and density were achieved in particular when the material mixture used was compacted by a compression factor of > 1.4 (Examples 4 and 13), in particular of > 2.0 (Example 4).

[0130] Variation of the elastomer-containing powder (Example 16)

[0131] According to the invention, material mixtures based on any elastomer-containing powder or granules can be used. As an example, a material mixture was produced according to Example 16 using the procedure described above in connection with Examples 1-6, but using an SBR rubber powder instead of the elastomer-containing powder from scrap tires. For this purpose, the starting materials listed in Table 6 were mixed in the specified amounts in a Hauschild SpeedMixer DAC 400 mixer (Hauschild GmbH & Co. KG, Germany) at high mixing speed (1,800 rpm) to form a homogeneous material mixture. The material mixture was heated to a temperature of 85°C ± 5°C.

[0132] Table 6:

[0133] 9: Vulcanized SBR rubber powder, commercially available from Roth International

[0134] The determined bulk density of the mixture obtained in this way is also given in Table 6.

[0135] From the obtained SBR-based material mixture, a compact was produced by compression molding (with an unheated mold) as described above in connection with Examples 1-6, and this compact was investigated with regard to its properties.

[0136] The resulting pellet had a relatively high density (0.89 g / cm 3 ). It was also characterized by a high degree of strength and very good material cohesion (rating of 5 on the scale of 0 to 5 explained above). Production of molded articles from cross-linked elastomer compounds

[0137] From the compacts produced according to the invention from crosslinkable material, moldings can be produced by vulcanizing the crosslinkable composition to form an elastomer mass, whereby - in contrast to the powdered starting mixtures - molding tools can advantageously be used without difficulty, such as are otherwise used for processing raw rubber-based feedstocks.

[0138] This is illustrated here by way of example using the example of compacts produced from the material mixture described above according to Example 4, compared to further processing of the powdered starting material mixture into molded bodies made of a cross-linked elastomer mass.

[0139] For this purpose, a heatable, two-part steel compression mold was used. It consists of a lower cylindrical body with a hemispherical recess (diameter: 61.5 mm) in the center of its upper side for material reception, and an upper pressure plate with a hemispherical projection on its underside with a smaller diameter (57.7 mm) than the hemispherical recess. The upper pressure plate can be centered on the lower cylindrical body via guides so that the hemispherical projection of the pressure plate engages centrally in the hemispherical recess of the lower cylindrical body. This type of compression mold is commonly used to produce hemispherical molded bodies, such as those used to make balls, from raw rubber-based materials.

[0140] In a first step, a compact made of a crosslinkable material was produced from the material mixture according to Example 4 of Table 1 as described above. The compact was produced as described above for Example 4, except that a mold made of ASA plastic with a cylindrical cavity of smaller diameter (40 mm) was used, and the pressure stamp was positioned for compression by means of the press that corresponds to a distance (h) of 20 mm between the flat stamping surface of the pressure stamp that comes into contact with the material mixture and the planar bottom surface of the cylindrical cavity.

[0141] To produce a molded body from a corresponding cross-linked elastomer compound, the heatable, two-part steel mold described above was heated to a temperature of 165°C. Subsequently, a) the compact produced as described above or b) the powdered starting mixture according to Example 4 of Table 1 was placed into the hemispherical material receptacle of the lower cylindrical body of the mold. The upper pressure plate was then centered on the lower cylindrical body of the mold via the guides, and the filled mold assembled in this way was inserted into a press (Lauffer RLKV 25 / 1), by means of which the upper pressure plate of the mold was pressed flush against the upper side of the lower cylindrical body.The hemispherical protrusion of the pressure plate engaged centrally in the hemispherical recess of the lower cylindrical body, thereby compressing the material located between the two. The filled mold, placed in the press, was held at a temperature of 165°C for 18 minutes to vulcanize the crosslinkable composition. After cooling, the pressure plate was removed from the cylindrical body of the mold, and the consolidated molded body obtained through the pressing and vulcanization process, which had a shape corresponding to half of a hollow sphere, was removed.

[0142] Filling the mold with the powdered starting mixture proved problematic. When using the powdered starting mixture, overfilling the hemispherical cavity of the mold was necessary to produce molded bodies in the shape specified by the mold, a half of a hollow sphere with a wall thickness of 3.8 mm. This resulted in contamination of the work area due to excess powder and associated material loss. Other geometries would not have been possible at all if the mold had been overfilled with the powdered starting mixture. However, producing the molded body using the compact was problem-free. Furthermore, transport and storage costs for the compacts are significantly lower than with the powdered starting mixture.

Claims

Patent claims 1. A method for producing a compact from a crosslinkable material, the method comprising: (a) Providing a mixture comprising: (i) a powder or granules containing at least one elastomer, and (ii) comprising one or more additives, having at least one solid binder, and having a melting or softening temperature (T m ) of 100°C or less, and ethylene unsaturated functional groups, (b) Compacting the mixture, heated to a temperature of less than 120°C, into a compact using a shaping tool, and (c) Demolding of the compact, after cooling, at a temperature of less than T m , in order to obtain the pellet from a crosslinkable material.

2. The method according to claim 1, wherein the powder or granules contain at least one recycled elastomer, wherein the powder or granules are preferably provided by a process for recycling used tires or parts thereof, and / or wherein the at least one elastomer comprises a cross-linked natural rubber, a cross-linked synthetic rubber, a thermoplastic elastomer or a mixture or combination thereof.

3. The method according to any one of claims 1 or 2, wherein the at least one binder has a melting or softening temperature (Tmelting). m ) in the range of 30°C to 80°C and / or wherein the at least one binder comprises ethylene unsaturated functional groups.

4. The method according to any one of claims 1 to 3, wherein the at least one binder comprises at least one thermoplastic polymer, a resin, an ionomer, a wax, or a mixture or combination thereof.

5. The method according to any one of claims 1 to 4, wherein the at least one binder comprises or consists of at least one polyalkenamer, preferably a poly-C5-Ci5-alkenamer, in particular a polyoctenamer.

6. The method according to any one of claims 1 to 5, wherein the mixture provided in step (a) further comprises a crosslinking agent, wherein the at least one crosslinking agent preferably comprises sulfur or a peroxide, in particular sulfur, and / or wherein the mixture provided in step (a) further comprises (iii) at least one polymer composed of components (i) and (ii) is different, wherein the at least one polymer (iii) preferably comprises a thermoplastic polymer, in particular a polyolefin, and / or wherein the polymer (iii) preferably comprises a recycled polymer. The method according to any one of claims 1 to 6, wherein the mixture in step (b) is compacted by a compression factor of at least 1.2, preferably at least 1.4 or at least 1.7 or at least 2.0, for example in a range of 1.8 to 4.0 or from 2.0 to 3.0, and / or wherein the compaction in step (b) is carried out under conditions under which the binder is malleable and / or flowable. The method according to any one of claims 1 to 7, wherein the mixture is heated to a temperature in the range of 40°C to <120°C, preferably to a temperature in the range of 60°C to 110°C. The method according to any one of claims 1 to 8, wherein the demolding in step (c) at a temperature of 60°C or less, such as 40°C or less, for example in the range of 10°C to 40°C. A pellet made of a crosslinkable material obtainable according to the method of any one of claims 1 to 9. The pellet according to claim 10, wherein the pellet has a volume of less than or equal to 500 cm³. 3and / or has a maximum length of less than or equal to 200 cm and / or wherein the compact is pre-portioned, wherein the compact preferably has one or more predetermined breaking points and / or wherein the compact is in the form of a roll, coil, spindle or a layered or superimposed structure. A method for producing a molded body comprising: (I) (a) Providing a pellet made of a crosslinkable material according to any one of claims 10 or 11, and (b) Crosslinking the crosslinkable material to form a crosslinked elastomeric mass, or (II) (a) Providing a feed material for a forming tool, wherein the feed material comprises at least one compact made of a crosslinkable material according to any one of claims 10 or 11 or one or more parts thereof, (b) Shaping the input material into a desired shape using the shaping tool, and (c) Crosslinking the feedstock material to form a crosslinked elastomeric compound. The method according to claim 12, wherein the crosslinking is carried out at a temperature in the range of 140 to 200°C and / or for a time of 60 minutes or less, and / or wherein the shaping is carried out by compression molding, extrusion, or injection molding. A molded body comprising a crosslinked elastomeric compound obtainable according to the method according to any one of claims 12 or 13. Use of a compact made of a crosslinkable material according to any one of claims 10 or 11, or one or more parts thereof, for the manufacture of an article comprising a crosslinked elastomeric compound and / or for the substitution of raw rubber or raw rubber-containing compositions.

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