DE102017201703A1 - Composite, production process for a composite and formed from the composite molding - Google Patents

Abstract

The invention relates to a method for producing a composite, wherein the composite (1) contains a matrix (2) which is formed completely or at least partially by a first material (3) and in which particles of a second material (5) are embedded,
the method comprising the steps of:
Providing an intermediate composite, wherein the intermediate composite contains a matrix in which particles of the second material (5) are embedded,
Providing a different material from the intermediate composite, which
Particles of the second material (5) includes or
is at least partially formed by the first material (3),
Merging the intermediate composite with the further material and
- Mixing of the intermediate composite with the other material.
The invention also relates to a composite (1) and a molded part.

Description

The invention relates to a composite, a production process for a composite and a molded body formed from the composite.

A composite, also referred to as a composite material or a composite material, consists of two or more interconnected materials, which are also referred to as components of the composite. A composite typically has a matrix in which particles, fibers or both particles and fibers are incorporated. The matrix may be formed of a polymer such as a thermoplastic or other material. The embedded in the matrix particles and / or fibers, which are also referred to as fillers may be formed for example of a metal, carbon or other material.

The properties of the composite depend on the one hand on the physical and chemical properties of the components of the composite. In addition, the properties of the composite are also affected by the relative proportions of the components, particularly the relative proportions of the particles in the composite, the uniformity of the spatial distribution of the particles within the composite, and other factors.

In some applications, a high relative amount of the particular filler, also referred to as a degree of filling, sought in order to achieve certain properties of the composite, such as a high electrical and / or thermal conductivity. On the other hand, a high degree of filling of a filler can lower the processability of the composite. For example, a high degree of filling can lead to a high viscosity of the composite and thus make it difficult, for example, to use molding processes such as injection molding or extrusion or other processes. In addition, a high degree of filling may, in some cases, result in the formation of agglomerates of the filler in the composite, which may adversely affect the properties of the composite.

It is thus the object of the present invention to propose a production method for a composite, with which the properties of the composite can be predetermined and controlled as well as possible, such as, for example, the electrical and / or thermal conductivity of the composite. On the other hand, however, the problems described above should be avoided as much as possible. The composite produced in this way should therefore still be easy to process, even if the filling level of the filler is high, and unwanted agglomerates of the filler should be avoided as much as possible. In addition, a corresponding composite and a molded body formed therefrom are proposed.

This object is achieved by a method for producing a composite according to the main claim and by a composite and a shaped body according to the independent claims. Embodiments and developments of the method, the composite and the molding result from the dependent claims, the following description and the figures.

With the method proposed here, a composite can be produced which contains a matrix which is formed completely or at least partially by a first material. Particles of a second material are embedded in the matrix.

The first material may be, for example, a thermoplastic or include a thermoplastic. The first material may also include two or more different thermoplastics. Suitable thermoplastics include, for example, thermoplastic polymers and thermoplastic elastomers. The first material may include, for example, one or more of the following materials: polyamide (Pa) 6, Pa 66, Pa 12, Pa 4,6, acrylonitrile-butadiene-styrene copolymer (ABS), polycarbonates (PC), polyethylene (PE), polypropylene (PP), polyphenylene sulfide (PPS), polyvinyl chloride (PVC), acrylonitrile-styrene-acrylate copolymer (ASA), thermoplastic urethane (TPU), ethylene-propylene-diene rubber (EPDM), thermoplastic polyester (TPC). Typically, the first material is an electrical insulator.

The second material may be, for example, electrically and / or thermally conductive. The second material may be formed of carbon or include carbon, for example. As a second material, for example, graphite, graphene or carbon black and combinations or mixtures thereof in question. Thus, the particles of the second material may be formed, for example, completely or at least partially made of carbon, for example, the particles may thus each consist entirely or at least partially of graphite, graphene or carbon black. Such particles have a high electrical and thermal conductivity and a much better corrosion resistance compared to particles of metal. In principle, it is possible that the composite can be changed by introducing further particles in addition to these particles which differ from the first-mentioned particles, for example by the material from which they are formed, by their size and / or by their size Shape.

• - Bereitstellen eines Zwischenkomposits, wobei das Zwischenkomposit eine Matrix beinhaltet, in die Partikel des zweiten Materials eingelagert sind,
• - Bereitstellen eines von dem Zwischenkomposit verschiedenen weiteren Materials,

• - Zusammenführen des Zwischenkomposits mit dem weiteren Material und
• - Vermischen des Zwischenkomposits mit dem weiteren Material.

The proposed method comprises the following steps:

• Providing an intermediate composite, wherein the intermediate composite contains a matrix in which particles of the second material are embedded,
• Providing a further material different from the intermediate composite,

• Merging the intermediate composite with the further material and
• - Mixing of the intermediate composite with the other material.

The composite is formed from the intermediate composite mixed with the further material. Forming the composite is also referred to as compounding (or compounding). In this case, for example, a mixing device, such as an extruder, can be used. Possible extruders are, for example, a single-screw extruder, a co-rotating twin-screw extruder, a counter-rotating twin-screw extruder or a planetary roller extruder.

For the formation of the composite, the method may include, in addition to the merging and mixing, further steps that may be performed sequentially or synchronously, such as crushing, conveying, melting, dispersing, degassing and pressure build-up.

It can be provided, for example, that the intermediate composite is provided as a solid. Additionally or alternatively, it is possible that the further material is provided as a solid. For example, therefore, the intermediate composite and the further material can be provided as solids and combined, for example as granules.

The intermediate composite can, for example, be mechanically comminuted by a force and in this case, for example, be converted into a (finer) granular or pulverulent state. Accordingly, it is also possible that the further material is mechanically comminuted by a force and this case, for example, in a (finer) granular or powdery state is transferred.

A force on the intermediate composite and the other material can also be done when mixing the Zwischenkomposits with the other material.

The action of force may thus occur, for example, before the mixing step, for example during the comminution, or during the mixing step. The force can be effected for example by the above-mentioned mixing device or by an additional mechanically operating crushing machine.

For example, it is possible with the proposed method to break up agglomerates formed by particles of the second material, for example by the described action of force on the intermediate composite and / or the further material. By the action of force, it is also possible to deform the particles of the second material, for example to flatten, compact and / or round edges of the particles.

As described above, the intermediate composite includes particles of the second material, such as in variants A, B and A + B described below. As a result of the described action of force (for example during comminution or mixing), agglomerates of the particles, if present, can be broken up in the intermediate composite. In addition, it is possible in this way to deform the particles and / or to align relative to each other.

The deformation and mutual orientation of the particles as well as the degradation of agglomerates makes it possible to introduce the particles more homogeneously into the matrix of the polymer. In this way, a relatively high degree of filling can be realized or at a given degree of filling a relatively low viscosity of the composite can be achieved.

For example, the intermediate composite and / or the further material may be heated prior to the mixing step or during the mixing step and completely or at least partially converted to a molten state, for example by frictional heat during mixing or dicing or by means of an additional heat source. For example, the first material may be melted, especially if the first material is or contains a thermoplastic polymer. If present, for example in the intermediate composite, the soldering materials mentioned below can also be melted during heating. The particles of the second material typically do not melt during the process but remain solid. Typically, these particles are dispersed in the first material as the intermediate composite is mixed with the other material. If the first material has melted, the distribution of the particles of the second material in the first material takes place, for example, by dispersing.

The intermediate composite, as described above, is also a composite and can For example, be prepared in a conventional manner or by the method proposed here. If reference is made to "the composite" below, this always means the composite formed from the intermediate composite and the further material and not the intermediate composite.

For the intermediate composite and the other material different variants are possible. For example, the further material may include particles of the above-mentioned second material or be formed entirely by these particles (see, for example, variants A and A + B below). In addition to the particles of the second material, the further material may comprise, for example, a solder material in which the particles are embedded (see, for example, variant A + B below). The further material may be, for example, a further or second intermediate composite. In another example, the further material is completely or at least partially formed by the abovementioned first material which, for example, forms the matrix of the composite (see, for example, variant B below). In this case, the matrix of the intermediate composite may be formed completely or at least partially by a solder material in which the particles of the second material are embedded.

Said solder material may, for example, be a low-melting alloy, for example a ZnSn alloy. Suitable solder materials, for example, have eutectic melting points of about 190 ° C to 210 ° C.

The intermediate composite and the further material typically differ in their material compositions, in particular by the relative proportions of the materials contained in the intermediate composite and in the further material. The relative proportions are typically relative mass fractions, abbreviated by wt% or wt%.

For example, the relative amount of the first material in the intermediate composite may be different, for example, higher or lower, from the relative amount of the first material in the other material. For example, the first material is included in the intermediate composite, but not in the other material (see, for example, variants A and A + B below).

In another example, the first material is contained in the further material, or even forms the additional material, but is not included in the intermediate composite (see, for example, variant B below). In addition, for example, the relative amount of the second material in the intermediate composite may be different, for example, higher or lower, from the relative proportion of the second material in the other material. For example, the second material is included in the intermediate composite, but not or at a lower relative level in the other material (see, for example, variant B below). In another example, the second material is included in the further material, but not or only to a lesser relative amount in the intermediate composite (see, for example, Variants A and B below).

• - aus den relativen Mengenanteilen des ersten Materials, des zweiten Materials und ggf. weiterer Komponenten in dem Zwischenkomposit,
• - aus den relativen Mengenanteilen des ersten Materials und des zweiten Materials und ggf. weiterer Komponenten in dem weiteren Material sowie
• - aus dem relativen Mengenverhältnis von Zwischenkomposit und dem weiteren Material beim Vermischen des Zwischenkomposits und dem weiteren Material.

Typically, the relative proportions of the first material, the second material and possibly other components in the composite arise

• from the relative proportions of the first material, the second material and optionally further components in the intermediate composite,
• - From the relative proportions of the first material and the second material and optionally other components in the other material and
• - From the relative proportion of Zwischenkomposit and the other material in mixing the Zwischenkomposits and the other material.

As already mentioned above, the particles embedded in the matrix of the intermediate composite are particles of the second material. The particles embedded in the matrix of the intermediate composite typically belong to those particles which are incorporated into the matrix of the composite at the end of the process (see, for example, variants A and A + B below). In such examples, in which the further material also includes particles of the second material, these also typically belong to those particles which are incorporated into the matrix of the composite at the end of the process (see, for example, variant A + B below).

As already described above, the matrix of the intermediate composite may include the first material or be formed by the first material. The further material then typically includes particles of the second material. A relative proportion of the particles of the second material in the intermediate composite may be less than a relative proportion of the particles of the second material in the composite. In these cases, in particular in variants A and A + B described below, it is possible, for example, to apply the proposed method several times, for example in order to achieve the desired proportion of the particles of the second material of the composite in several steps. For example, the method may be performed N + 1 times with N ≥ 1, where N is for example 1, 2 or a larger natural number is. In the case of the first N feedthroughs, a precursor of the ultimately to be achieved composite is produced as a composite and used as the intermediate composite in the respectively subsequent execution. The composite obtained in the N + 1th implementation then corresponds to the desired composite.

For example, the relative amount of particles of the second material in the intermediate composite may be in a range of from 20 weight percent to 40 weight percent, for example, between 30 weight percent and 40 weight percent. For example, the relative amount of particles of the second material in the composite may range from 20% to 75% by weight.

It will accordingly be seen that the relative amount of the first material in the intermediate composite is typically higher than the relative amount of the first material in the composite.

In a first exemplary variant of the proposed method, which is also referred to as variant A, the matrix of the intermediate composite is completely or at least partially formed by the first material, for example by a thermoplastic. In variant A, the matrix of the composite is typically formed completely, or at least partially, by the first material originating from the intermediate composite.

For example, in variant A, the intermediate composite contains the particles of the second material only with a lower relative proportion (degree of filling) than the composite.

In the variant A, the further material is typically given completely or at least partially by the second material, for example by particles of the second material. In variant A, the relative proportion of the particles of the second material in the further material is typically higher than in the intermediate composite. Typically, in variant A, the first material in the other material is not included or only in negligible proportions.

In variant A, the intermediate composite - except for the smaller relative proportion (degree of filling) of the particles of the second material - typically corresponds to the composite. By combining the intermediate composite with the further material and mixing the intermediate composite with the further material, the relative proportion of the particles of the second material is increased to the desired value in the composite. By iteratively increasing the relative proportion (degree of filling) of the particles of the second material in variant A, it can be achieved, in particular, that the particles are evenly distributed in the matrix of the composite, even at a high degree of filling. In particular, the formation of undesirable agglomerates of the particles in the composite can be avoided or at least reduced in this way.

In a further exemplary embodiment, which is referred to as variant B, the further material is typically formed completely, but at least partially, by the first material, for example by a thermoplastic.

The matrix of the intermediate composite is formed in variant B, for example, by a solder material. In contrast to variant A, the matrix of the intermediate composite does not correspond to the matrix of the composite. The particles of the second material, which are embedded in the matrix of the intermediate composite, may for example be formed from an electrically conductive material, such as graphite. In variant B, the intermediate composite is, for example, a solder / graphite composite or a solder / graphene composite. In preparing the intermediate composite, the solder material is typically melted and the particles of the second material are combined with the molten solder material and mixed.

In variant B, during the mixing of the intermediate composite with the further material, the particles of the second material from the intermediate composite are incorporated into the first material, which then forms the matrix of the composite. The solder material encases the particles embedded in this matrix and typically also forms connection paths or bridges between the embedded particles. The solder bridges achieve a particularly high electrical and thermal conductivity. In addition, the solder material allows a good processability of the composite even at high degrees of filling. If, for example, the composite is heated during processing until the solder material in the composite changes into a molten phase, the viscosity of the composite is greatly reduced and the processability improves.

In a further exemplary embodiment, which to a certain extent represents a combination of the variants A and B described above and is therefore referred to as variant A + B, the matrix of the intermediate composite, as in variant A, is formed entirely or at least partially by the first material, for example by a thermoplastic. In the variant A + B, the matrix of the composite is thus typically formed completely, or at least partially, by the first material originating from the intermediate composite.

As in variant A, in the variant A + B the intermediate composite also contains the particles of second material with a lower relative proportion (degree of filling) than the composite. In variant A + B, the relative proportion of the particles of the second material in the further material is typically higher than in the intermediate composite. Typically, in the variant A + B, the first material in the other material is not or only to negligible proportions contained.

The further material is given in variant A + B by another intermediate composite, which corresponds to the intermediate composite of variant B and is referred to in variant A + B as a second intermediate composite. In variant A + B, the further material is, for example, a solder / graphite composite or a solder / graphene composite.

In the variant A + B, when mixing the (first) intermediate composite with the further material, ie the second intermediate composite, the particles of the second material from the second intermediate composite are incorporated into the first material originating from the (first) intermediate composite, which thus, as in FIG Variant A forms the matrix of the (finally produced) composite. As in variant B, the solder material encases the particles embedded in the matrix and typically forms connection paths or bridges between the embedded particles. This results in the advantages described with respect to variants A and B with respect to uniformity, electrical and thermal conductivity and processability.

The composite proposed here has been produced by the method proposed here. The composition and properties of the composite depend on the choice of components, in particular the first and second materials and, as the case may be, the choice of soldering material. Thus, the composite may be, for example, a graphite-thermoplastic composite, a graphene-thermoplastic composite, a graphite-solder-material-thermoplastic composite, or a graphene-solder-material-thermoplastic composite. In addition, combinations of graphite, graphene and / or carbon black are also possible in the composite. The solder material may be, for example, a ZnSn alloy or another low-melting alloy.

If a solder material is present in the composite, the particles embedded in the matrix can, for example, be encased by the solder material, which can also form connection paths or bridges between the embedded particles.

In addition, the shape of the embedded particles may differ from an original form of the particles. For example, the particles may have a flattened and / or rounded shape and / or rounded edges compared to an original shape of the particles. In addition, agglomerates of the particles can be avoided or at least reduced despite high filling levels. By the achievable with the proposed method high degree of filling of the particles in the composite, it is possible, for example, to achieve a high electrical and thermal conductivity of the composite and / or high strength of the composite.

For example, the relative amount of particles of the second material in the composite may range from 20% to 75% by weight.

The molding proposed here is completely or at least partially formed from such a composite. For example, a shape of the molded article may have been produced by using a plastic molding method such as an injection molding method, an extrusion method, a rolling method, a pressing method or a calendering method. For this purpose, advantageously established plants can be used.

If the composite comprises the described solder material, a low viscosity of the composite can be achieved thereby even with a high proportion of the particles, whereby the processing of the composite is simplified. In addition, the described deformation and mutual orientation of the particles as well as the reduction of agglomerates can contribute to a relatively low viscosity and good processability of the composite.

The composite and the molded article can be used in a variety of ways. For example, the molded article may be configured and used as part of a heat exchanger, as part of a sealing element, as part of a bipolar plate of a fuel cell, as part of an electromagnetic wave shielding device, as an active heating or cooling element, or as a filament of a 3D printer ,

• 1 ein Flussdiagramm eines Ausführungsbeispiels des hier vorgeschlagenen Herstellungsverfahrens,
• 2 eine schematische Darstellung eines Querschnittes eines Beispiels eines Komposits hier vorgeschlagener Art,
• 3 eine schematische Darstellung eines Querschnittes eines weiteren Beispiels eines Komposits hier vorgeschlagener Art, und
• 4 eine schematische Darstellung eines Querschnittes eines weiteren Beispiels eines Komposits hier vorgeschlagener Art.

In the following, the proposed method, the proposed composite and the proposed molding will be explained in more detail by means of exemplary embodiments and with reference to FIGS. 1 to 3. It shows:

• 1 a flowchart of an embodiment of the manufacturing method proposed here,
• 2 1 is a schematic representation of a cross-section of an example of a composite of a type proposed here;
• 3 a schematic representation of a cross section of another example of a composite of the type proposed here, and
• 4 a schematic representation of a cross section of another example of a composite proposed here type.

Corresponding or identical features are provided in the figures with the same reference numerals.

In 1 FIG. 4 is a flowchart of one embodiment of the method for manufacturing a composite proposed here. FIG 1 shown. The composite 1 contains a matrix 2 that completely or at least partially through a first material 3 is formed. Into the matrix 2 are particles 4 a second material 5 stored.

In the examples described below, the first material is 3 for example a thermoplastic polymer, for example a polyamide (Pa) 6 , At the first material 3 but it could also be another of the above examples of the first material.

The second material 5 is an electrically and thermally conductive material, for example graphite, in the examples described below. The particles 3 In this example, therefore, they are formed completely or at least partially from graphite.

In the 2 to 4 Fig. 2 are schematic representations of cross sections of various examples of such a composite 1 shown.

At the in 2 shown example of the composite 1 it is a graphite-polymer composite, which has been prepared for example according to the variant A described above. The particles 4 have a particularly high degree of filling and have been deagglomerated by the process management, flattened, rounded and mutually aligned, resulting in this example in a high degree of filling of up to 75% by weight.

At the in 3 shown example of the composite 1 it is a graphite-ZnSn-polymer composite, which has been prepared for example according to the variant B described above, resulting in this example in a high degree of filling of up to 75% by weight. The particles 4 differ in their shape. This is what some particles show 4 a round shape and other particles a shape with peaks and / or edges. The composite 1 includes in this example a solder material 6 which in this example is given by a ZnSn alloy and which is the particle 4 individually sheathed and connecting bridges 7 between the particles 4 forms.

At the in 4 shown example of the composite 1 it is a graphite-ZnSn-polymer composite, which has been prepared for example according to the above-described variant A + B. The particles 4 wise as in the 2 Example shown a particularly high degree of filling and have been deagglomerated by the process management, flattened, rounded and mutually aligned, resulting in this example in a high degree of filling of up to 75% by weight. In addition, the composite has 1 in this example, a solder material 6 which in this example is given by a ZnSn alloy as in the above example and which is the particle 4 individually sheathed and connecting bridges 7 between the particles 4 forms.

• S1: Bereitstellen eines Zwischenkomposits, wobei das Zwischenkomposit eine Matrix beinhaltet, in die Partikel des zweiten Materials eingelagert sind,
• S2: Bereitstellen eines von dem Zwischenkomposit verschiedenen weiteren Materials,
• S3: Zusammenführen des Zwischenkomposits mit dem weiteren Material und
• S4: Vermischen des Zwischenkomposits mit dem weiteren Material. In diesem Schritt wird aus dem mit dem weiteren Material vermischten Zwischenkomposit das Komposit gebildet. Hierbei werden insbesondere die Partikel in dem Thermoplasten verteilt und darin eingelagert. Beispielsweise wird als Mischvorrichtung ein Extruder verwendet, beispielsweise kommen ein Einschneckenextruder, ein gleichläufiger Doppelschneckenextruder, ein gegenläufiger Doppelschneckenextruder oder ein Planetwalzenextruder in Frage.
• In dem Schritt S5 wird beispielsweise entschieden, ob die Schritte S1 bis S4 wiederholt werden sollen oder ob der Schritt S6 durchgeführt werden soll.

As in 1 is shown, the method comprises the steps:

• S1: providing an intermediate composite, wherein the intermediate composite contains a matrix in which particles of the second material are embedded,
• S2: providing a further material other than the intermediate composite,
• S3: Merging the Zwischenkomposits with the other material and
• S4: Mixing of the intermediate composite with the other material. In this step, the composite is formed from the intermediate composite mixed with the further material. Here, in particular, the particles are distributed in the thermoplastic and stored therein. For example, an extruder is used as the mixing apparatus, for example, a single-screw extruder, a co-rotating twin-screw extruder, a counter-rotating twin-screw extruder or a planetary roller extruder.
• In step S5, for example, it is decided whether steps S1 to S4 should be repeated or step S6 should be performed.

In a repetition of steps S1 to S4, the last composite generated is used as a new intermediate composite for the following steps S1 to S4. In this way, the degree of filling of the composite is increased iteratively. This iterative process is used, for example, in the production of in 2 and 4 shown examples of the composite 1 carried out according to the variant A or A + B.

In the in the 2 and 4 Examples shown according to variants A and A + B is the relative proportion of the particles of the second material 5 in the intermediate composite in step S1 (in the first iteration of the process), for example, in a range of 20% by weight to 40% by weight. Of the relative proportion of particles 4 of the second material in the composite (after the last iteration of the process) is, for example, in a range of 20% to 75% by weight.

In the step 6 becomes from the composite generated in the previous step S4 1 a molded body produced. In this case, the composite is brought into the desired shape of the shaped body, for example by using a plastic molding process, for example by an injection molding process, an extrusion process, a rolling process, a pressing process or a calendering process. For this purpose, a conventional system can be used.

The shaped body can be, for example, a heat exchanger, a sealing element, a bipolar plate of a fuel cell, a shield against electromagnetic waves, an active heating or cooling element or a filament of a 3D printer.

In step S1, the intermediate composite is provided, for example, as a solid and is optionally also mechanically comminuted by means of a force and in this way, for example, converted into a granular or pulverulent state.

In step S2, the further material is also provided as a solid and optionally mechanically comminuted by a force and thus converted into a granular or powdery state.

Additionally or alternatively, a force can also be applied during mixing to the intermediate composite and the further material in step S4.

The force action can thus take place, for example, before the step S4 of the mixing, for example during the comminution, or during the step S4 of the mixing. The force can be effected for example by the above-mentioned mixing device or by an additional mechanically operating crushing machine.

Due to the force described, which is used in particular in the variants A and A + B, are agglomerates passing through the particles 4 of the second material 5 are formed, broken up. Besides, as in 2 and 4 shown is the particles 4 deformed, for example, flattened and compacted, and edges of the particles 4 are rounded off. In addition, the particles become 4 aligned approximately parallel to one another. Overall, in these variants, therefore, a particularly high degree of filling of the particles 4 achieved.

In steps S1 to S4, the intermediate composite and / or the further material can be heated and converted completely or at least partially into a molten state, for example by frictional heat during mixing in step S4 or during cutting in steps S1 and S2. For example, during mixing in step S4, the first material, ie the thermoplastic, is melted. In variants B and A + B, the soldering material can also be melted when the intermediate composite is heated. The particles of the second material do not melt during the process but remain solid.

The intermediate composite and the other material differ between the in 2 to 4 shown examples.

In the in 2 shown example according to variant A is the matrix of Zwischenkomposits by the first material 3 formed, so by the mentioned thermoplastics. As described above, the intermediate composite (in the first iteration of the process) contains the particles of the second material with a lower relative amount (degree of filling) than the composite.

The further material is in this example according to the variant A completely by the second material 5 given, for example, by a granulate of the second material 5 or through the particles 4 of the second material 5 , The first material 3 is not included in the other material.

In the in 3 shown example according to variant B, the other material, for example, completely by the first material 3 formed, so by the above-mentioned thermoplastic.

The matrix of the intermediate composite is in this example according to variant B by the solder material 6 educated. In variant B, the intermediate composite is, for example, a solder / graphite composite. In preparing the intermediate composite, the solder material is melted and the particles of the second material are combined with the molten solder material and mixed.

In step S4, in this example according to variant B, the particles 4 of the second material 5 from the intermediate composite into the first material 3 embedded, which then the matrix 2 of the composite 1 forms.

In the in 4 In the example shown in variant A + B, the matrix of the intermediate composite is as in FIG 2 shown example according to the variant A completely through the first material 3 formed, so by the mentioned thermoplastics. The matrix 2 of the composite 1 in this example is completely by the first material derived from the intermediate composite 3 educated.

As in the in 2 In the example shown in variant A, the intermediate composite also contains the particles in this example according to variant A + B 4 of the second material 2 with a lower relative proportion (degree of filling) than the composite 1 , The further material is given in this example according to the variant A + B by a further (second) intermediate composite, which the above-described intermediate composite of in 3 shown example according to variant B corresponds.

In step S4, the particles in this example become 4 of the second material 5 from the second intermediate composite into the first material originating from the (first) intermediate composite 3 stored, which thus, as in variant A, the matrix 2 of the (finished) composite 1 forms.

Optionally, in the example described, surfaces of the particles 4 of the second material 5 be modified by means of a plasma coating, typically before the step S3 of combining the Zwischenkomposits with the other material.

The composite 1 is characterized in each of the examples shown by a high electrical conductivity and high thermal conductivity. The materials used are toxicologically safe and easy to recycle. The composite has good processability even at high fill levels and is also inexpensive.

Claims (17)

Method for producing a composite (1), wherein the composite (1) contains a matrix (2) which is formed completely or at least partially by a first material (3) and embedded in the particles (4) of a second material (5) are, the method comprising the following steps: Providing an intermediate composite, wherein the intermediate composite contains a matrix in which particles (4) of the second material (5) are embedded, Providing a different material from the intermediate composite, which Particles (4) of the second material (5) comprises or at least partially formed by the first material (3), Merging the intermediate composite with the further material and - Mixing of the intermediate composite with the other material. Method according to Claim 1 , characterized in that the intermediate composite is mechanically comminuted prior to the mixing step or during the mixing step. Method according to one of the preceding claims, characterized in that the intermediate composite is heated and converted into a molten state before the mixing step or during the mixing step. Method according to one of the preceding claims, characterized in that the further material is mechanically comminuted before the step of mixing or during the step of mixing by a force. Method according to one of the preceding claims, characterized in that the further material is heated and converted into a molten state before the mixing step or during the mixing step. Method according to one of the preceding claims, characterized in that the matrix of the intermediate composite comprises the first material (3) or is formed by the first material (3), wherein a relative proportion of the particles (4) of the second material (5) in the Intermediate composite is less than a relative proportion of the particles (4) of the second material (5) in the composite. Method according to one of the preceding claims, characterized in that the relative proportion of the particles (4) of the second material (5) in the intermediate composite in a range of 20 wt% to 40% by weight. Method according to one of the preceding claims, characterized in that a relative proportion of the particles (4) of the second material (5) in the composite (1) is in a range of 20 wt% to 75 wt%. Method according to one of the preceding claims, characterized in that the matrix of the intermediate composite is formed completely or at least partially by a solder material (6). Method according to one of the preceding claims, characterized in that - the first material (3) is not contained in the intermediate composite or - that the first material (3) is contained in the intermediate composite and a relative proportion of the first material (3) in the Intermediate composite higher is a relative proportion of the first material (3) in the composite (1). Method according to one of the preceding claims, characterized in that the first material (3) is or includes a thermoplastic polymer. Method according to one of the preceding claims, characterized in that the particles of the second material (5) consist entirely or at least partially of carbon, for example of graphite and / or graphene. Method according to one of the preceding claims, characterized in that the second material (5) is electrically conductive. Composite produced by a method according to any one of the preceding claims. Shaped body, the whole or at least partially from a composite (1) according to Claim 14 is formed. Molded body after Claim 15 characterized in that a shape of the molded article has been produced by using a plastic molding method, for example, an injection molding method, an extrusion method, a rolling method, a pressing method or a calendering method. Shaped body according to one of Claims 15 or 16 wherein the shaped body is designed as part of a heat exchanger, as part of a sealing element, as part of a bipolar plate of a fuel cell, as part of an apparatus for shielding against electromagnetic waves, as an active heating or cooling element or as a filament of a 3D printer.

Images