Cofilaments, rovings, yarns, semi-finished products, uses of cofilaments, and methods for manufacturing cofilaments.

Abstract

The present invention relates to a cofilament comprising a first filament and a second filament. [Solution] The first filament is made of an organic material and has a glass transition temperature of 400°C or higher, and the second filament is made of a metallic material and is in contact with the first filament. Furthermore, the present invention relates to rovings, yarns, and semi-finished products comprising this cofilament, the use of this cofilament, and a method for manufacturing this cofilament.

Description

Technical Field

[0001] The present invention relates to cofilaments, rovings, yarns, semi-finished products, the use of cofilaments, and methods for manufacturing cofilaments.

[0002] In particular, the present invention relates to cofilaments comprising a first filament made of an inorganic material and a second filament made of a metallic material.

Background Art

[0003] The importance of filaments in the technical field has been continuously increasing. This is especially due to the broadening of the range of properties exhibited by filaments known in the prior art.

[0004] In particular, in the fields of automotive technology, aircraft and aerospace technology, and filtration, especially in the catalyst field, filaments have been produced that are heat-resistant, cost-effective, and in addition, are also thermally and / or electrically conductive.

[0005] Various products made from filaments are used in the field of thermally and / or electrically conductive filaments that conduct electric current, and / or shield electromagnetic waves, and / or conduct heat, form antennas, etc.

[0006] Pure multifilament metal fibers are expensive, with a production price of 100 to 800 euros / kg, especially when the filament diameter is less than 50 micrometers, due to their manufacturing method, particularly the drawing method.

[0007] Polymer fibers electroplated with silver or aluminum are also not suitable for many applications, at 200 to 500 euros / kg, because they are a time-consuming two-step manufacturing process. Furthermore, depending on the polymer used, especially PA6, the continuous use temperature of 80°C is not sufficient for applications in the engine field.

[0008] While carbon fiber is cost-effective for many applications, costing between 10 and 100 euros per kilogram, its conductivity is insufficient, especially for electromagnetic shielding.

[0009] In many applications, such as electromagnetic shielding, textiles are laid flat and later plated with silver, copper, or aluminum. During draping, this layer can crack, and these cracks act as antennas, hindering shielding. The same applies to foil. Foils, metal sheets, and plates do not provide sufficient drape and shapeability for components or spaces, nor do they allow air to permeate through the layer, which makes cooling the equipment or space particularly difficult. [Overview of the project] [Problems that the invention aims to solve]

[0010] The problem that this invention is based on is to provide an improved or alternative form to the prior art. [Means for solving the problem]

[0011] According to a first aspect of the present invention, a cofilament comprising a first filament and a second filament, wherein the first filament is made of an inorganic material and has a glass transition temperature of 400°C or higher, and the second filament is made of a metallic material and is in contact with the first filament, solves the above problem.

[0012] The following terms are explained in relation to this.

[0013] First, it should be explicitly stated that within the scope of this patent application, indefinite articles and numerical indications such as "one," "two," etc., should generally be understood as "minimum" indications, i.e., "at least one," "at least two," etc., unless it is not clear from the respective context, or is obvious to a person skilled in the art, or technically necessary, that they can only mean "exactly one," "exactly two," etc.

[0014] Within the scope of this patent application, the expression “especially” should always be understood as introducing optional and preferred features. It should not be understood as meaning “moreover” or “that is.”

[0015] A "cofilament" refers to a fiber or filament of virtually infinite length, having two sub-filaments of different properties that extend longitudinally, where two materially distinct filaments are physically and / or chemically connected to each other. In particular, a cofilament has a length-to-diameter ratio of 1,000 or greater.

[0016] The "first filament" is understood to be a basic fiber made from inorganic material, produced from a nozzle, particularly by nozzle drawing or spinning. The "second filament" is understood to be a fiber produced by attaching molten metal to the first filament and allowing it to solidify on the first element. In other words, a filament represents a fiber with virtually infinite length.

[0017] The first filament may consist of inorganic and nonmetallic materials. The second filament may consist of organometallic materials. "Organometallic materials" are understood to be materials in which organic groups or organic compounds are directly bonded to metal atoms. In the sense of this explanation, it should be explicitly noted that metallic materials and / or organometallic materials do not have a glass transition temperature.

[0018] In particular, the cofilament, and therefore both the first and second filaments, have a length of 10 cm or more, preferably 1 m or more, and especially preferably 10 m or more.

[0019] The first filament can be directly connected to the second filament. In particular, the cofilament does not have a different material in the transition area between the first and second filaments. In particular, the first and second filaments are not connected by a composite material, especially a composite material containing synthetic resin or similar. In particular, the cofilament preferably has only residual moisture from the air in the transition area between the first and second filaments.

[0020] In particular, the cofilament consists of a first filament and a second filament. Specifically, the cofilament does not contain any material other than the first and second filaments, especially sizing.

[0021] The first filament is not pretreated, especially before the second filament adheres to the first filament, and is not pretreated under the action of a substance different from the substance of the first and / or second filament.

[0022] In particular, when the second filament adheres to the first filament, the first filament has a temperature higher than the ambient temperature. In particular, when the second filament adheres to the first filament, the first filament has a temperature of 40°C or higher, preferably 50°C or higher, and especially preferably 60°C or higher, and this temperature arises from the first heat when the first filament was first formed. In particular, when the second filament adheres to the first filament, the first filament has a temperature arising from the first heat when the first filament was first formed. In particular, the first filament is not heated before the second filament adheres to the first filament.

[0023] Before the second filament adheres to the first filament, the first filament can have a state where no more than 1 second, particularly no more than 0.5 second, and particularly preferably no more than 0.1 second has elapsed after the primary forming of the first filament. In particular, this can prevent or prevents the first filament from reacting with moisture in the surrounding air before the second filament adheres to the first filament.

[0024] The "inorganic substance" is understood to be a substance that does not contain plant or animal components or contains only a small amount of these as impurities. In particular, the inorganic substance is understood to be natural stone, particularly granite, basalt, slate, sandstone or limestone. In particular, the inorganic substance is understood to be a substance that does not contain carbon or contains only a small amount of carbon as an impurity. In particular, the inorganic substance means ceramic, crystallized glass or amorphous glass, particularly E glass, S glass or C glass.

[0025] The "metallic substance" particularly refers to substances located to the left and below the boundary line from boron to astatine in the periodic table of elements.

[0026] A filament "consisting of one substance" may also contain a small amount of impurities, particularly impurities resulting from process technology, in addition to this substance. Furthermore, in particular, a mixed metal consisting of a plurality of metallic substances is also conceivable. In particular, the mixed metal contains only a small amount of impurities.

[0027] The "glass transition temperature" of a substance, particularly glass, polymer or ceramic, represents the temperature at which the substance transitions from a hard aggregate state to a viscous or liquid state.

[0028] Here, a co-filament having two chemically and / or physically bonded filaments with different material properties of the substance is proposed, where the first filament consists of an inorganic substance and the second filament consists of a metallic substance.

[0029] This advantageously enables the integration of the material properties of the different filaments within the co-filament.

[0030] In particular, the first filament has a glass transition temperature of 500°C or higher, preferably 570°C or higher, and especially preferably 600°C or higher.

[0031] The cofilament has a first inorganic filament, thereby achieving high tensile strength, particularly 500 N / mm². 2 Tensile strength exceeding 55,000 N / mm², and high modulus of elasticity, especially 55,000 N / mm². 2 It is possible to achieve an elastic modulus exceeding this limit.

[0032] The cofilament has a second metal filament, thereby achieving particularly advantageous thermal and / or electrical conductivity, especially electrical resistance of less than 200 Ω / m.

[0033] According to a preferred embodiment, a second metal filament can be used to achieve a cofilament electrical resistance of less than 150 Ω / m, preferably less than 110 Ω / m, and particularly preferably less than 75 Ω / m. More preferably, a second metal filament can be used to achieve a cofilament electrical resistance of less than 50 Ω / m, preferably less than 30 Ω / m, and particularly preferably less than 20 Ω / m. Particularly preferably, a second metal filament can be used to achieve a cofilament electrical resistance of less than 10 Ω / m, preferably less than 8 Ω / m, and particularly preferably less than 5 Ω / m.

[0034] The bonding of the first inorganic filament and the second metal filament further enables excellent impact resistance, making the proposed cofilament well-suited for bulletproof applications. Furthermore, depending particularly on the material composition of the cofilament, excellent heat resistance and good light resistance can be obtained. We were able to demonstrate that the proposed cofilament has heat resistance up to at least 400°C, preferably at least 500°C, and particularly preferably at least 600°C.

[0035] Due to its high temperature resistance, the cofilament can be used in high-temperature environments, especially near engines. In such cases, its thermal conductivity also allows for heat dissipation through the cofilament, particularly for cooling the motor.

[0036] In addition, the cofilament proposed here achieves particularly good values ​​in terms of fatigue resistance and corrosion resistance.

[0037] The cofilament proposed here consists solely of naturally occurring materials and is therefore particularly environmentally friendly. In particular, the cofilament can be completely recycled chemically and / or physically.

[0038] Furthermore, the cofilament proposed here has superior chemical resistance compared to E-glass.

[0039] In addition, cofilaments are extremely flexible and can be further processed into textiles or textile semi-finished products.

[0040] Textiles or textile semi-finished products are fiber-based and may be nonwoven fabrics in particular. Textiles or textile semi-finished products are fiber-based and may be knitted fabrics in particular, especially knitted fabrics or knitted cloths. Textiles or textile semi-finished products are fiber-based and may be systems of drawn yarns in particular, especially mats or tapes. Textiles or textile semi-finished products are fiber-based and may be systems of crossed yarns in particular, especially woven fabrics or braided fabrics. Semi-finished products made from cofilaments remain highly flexible and can be draped into almost any desired final shape at the designated place of use.

[0041] In particular, in the case of nonwoven fabrics, the influence of the first inorganic filament makes it possible to achieve particularly good heat insulation properties in the nonwoven fabric.

[0042] In addition, the cofilaments can be further processed to form filter woven fabrics and / or filter nonwoven fabrics. By achieving extremely thin maximum lateral extension of 23 μm or less, a filter medium that is particularly fine for small particles but still permeable to air can be achieved.

[0043] Here, it is specifically proposed that, during the production of cofilaments, the first filament is initially formed by a nozzle drawing or spinning method, and then brought into contact with molten metal. The metal solidifies upon contact with the first filament, thereby forming a cofilament. This production method makes it possible to achieve particularly stable mutual adhesion between the two filaments, and the second filament is physically and / or chemically bonded to the first filament. Physically, the filaments are bonded to each other by static friction. Chemically, the metallic second filament can electrostatically adhere to the molecules of the inorganic first filament. Furthermore, the metallic second filament can be covalently bonded to the molecules of the inorganic first filament.

[0044] The adhesion of the second filament to the first filament is advantageous in that the cofilament does not decompose during the cleaning process, and in particular, the metallic second filament is not washed away from the inorganic first filament.

[0045] By combining the material properties of the first filament with those of the second filament, it is advantageous to achieve a cofilament that possesses novel material properties compared to known filaments, particularly excellent chemical bonding, high temperature resistance, especially high tensile strength, and high chemical resistance, all of which are combined with excellent thermal and / or electrical conductivity. Furthermore, by combining different materials, a reflective effect can be achieved, particularly with the second metal filament.

[0046] The cofilament proposed herein can be manufactured inexpensively, particularly by the method according to the fifth aspect of the present invention. Due to its low cost, the proposed cofilament base can replace existing products, opening up new application areas. Furthermore, it can open up new types of applications in the field of lightweight construction.

[0047] According to a purposeful embodiment, the first filament has a glass transition temperature of 660°C or higher, preferably 800°C or higher, and particularly preferably 1,000°C or higher.

[0048] In particular, the first filament has a glass transition temperature of 700°C or higher, preferably 800°C or higher, and especially preferably 900°C or higher. Furthermore, the first filament has a glass transition temperature of 950°C or higher, preferably 1050°C or higher, and especially preferably 1100°C or higher.

[0049] The aforementioned glass transition temperature of the first filament made of an inorganic material is advantageous in that the first filament has particularly good temperature resistance, and thus, in particular, a metallic material having a relatively high melting point can be used for the second filament and attached to the first filament of the cofilament in a molten state, thereby achieving a cofilament with particularly desirable material properties.

[0050] The above values ​​for the glass transition temperature of the first filament should not be understood as strict limits, but rather should be explicitly noted as potentially exceeding or falling below these values ​​on an technical scale without departing from the embodiments of the invention described herein. Simply put, these values ​​provide a guideline for the range of glass transition temperatures for the first filament proposed herein.

[0051] Preferably, the first filament has a bound oxygen content of 30% by mass or more, preferably 40% by mass or more, and particularly preferably 44% or more.

[0052] More preferably, the first filament has a bound oxygen content of 35% by mass or more, preferably 42% by mass or more, and particularly preferably 45% by mass or more.

[0053] The following terms are explained in relation to this.

[0054] The "bound oxygen content" of the first filament is understood to be the total of all bound oxygen contained in the first filament, in particular the total of bound oxygen of any molecules contained in the inorganic first filament.

[0055] Experiments have shown that the aforementioned range of bound oxygen content is particularly advantageous for adhesion between the second and first filaments, thereby enabling the achievement of particularly robust cofilaments.

[0056] The above values ​​for the bound oxygen content of the first filament should not be understood as strict limits, but rather it should be explicitly stated that they may be higher or lower on an technical scale without departing from the embodiments of the invention described herein. In short, these values ​​provide a guideline for the range of bound oxygen content of the first filament proposed herein.

[0057] In particular, according to a purposeful embodiment, the first filament has a silicon dioxide content of 45% by mass or more, preferably 50% by mass or more, and especially preferably 55% by mass or more.

[0058] Silicon dioxide is a network-forming agent that forms the basic molecular structure of the inorganic first filament. The above content makes it possible to improve the material properties of the inorganic first filament, particularly its mechanical properties, especially its tensile strength and / or modulus.

[0059] The experiment demonstrated that the aforementioned range of silicon dioxide can improve, in particular, the temperature resistance and thermal shock resistance of the cofilament.

[0060] The above values ​​regarding the silicon dioxide content of the first filament should not be understood as strict limits, but rather should be explicitly noted that they may be higher or lower on an technical scale without departing from the embodiments of the invention described herein. In short, these values ​​should provide a guideline for the range of silicon dioxide content proposed herein.

[0061] More preferably, the first filament has an aluminum oxide content of 12% by mass or more, preferably 14% by mass or more, and particularly preferably 16% by mass or more.

[0062] Aluminum oxide, like silicon dioxide, is a network-forming agent that forms the basic molecular structure of the inorganic first filament. The proportion of aluminum oxide supports the good properties of the first filament, particularly its mechanical properties, especially its tensile strength and / or modulus.

[0063] As demonstrated in the experiment, when aluminum is used as the metallic material for the second filament, a high proportion of aluminum oxide in the first filament can particularly favorably improve adhesion between the inorganic first filament and the aluminum second filament.

[0064] In particular, when aluminum is used as the metallic material for the second filament, aluminum oxide enables direct chemical bonding of the aluminum.

[0065] The above values ​​regarding the percentage of aluminum oxide in the first filament should not be understood as strict limits, but rather should be explicitly noted that they may be higher or lower on an technical scale without departing from the embodiments of the invention described herein. In short, these values ​​provide a guideline for the range of aluminum oxide content in the first filament proposed herein.

[0066] According to a purposeful embodiment, the first filament has a boron trioxide content of 0.5% by mass or less, preferably 0.1% by mass or less, and particularly preferably 0.01% by mass or less.

[0067] Boron trioxide is classified as a hazardous substance under EU chemical regulations. Therefore, a lower proportion of boron trioxide is advantageous.

[0068] Particularly preferably, the first filament does not contain a detectable amount of boron trioxide.

[0069] The above values ​​regarding the proportion of boron trioxide in the first filament should not be understood as strict limits, but rather should be explicitly noted that they may exceed or fall below these limits on an technical scale without departing from the embodiments of the invention described herein. In short, these values ​​provide a guideline for the range of boron trioxide in the first filament proposed herein.

[0070] According to a preferred embodiment, the first filament has a magnesium oxide content of 10% by mass or less, preferably 7% by mass or less, and particularly preferably 5% by mass or less.

[0071] Experiments have shown that increasing the proportion of magnesium oxide improves the surface tension of the inorganic starting material of the first filament in the liquid phase, thereby improving the drawability of the first filament in the liquid phase. Furthermore, increasing the proportion of magnesium dioxide suppresses crystallization. In addition, increasing the proportion of magnesium oxide can increase the hardness of the first filament. Moreover, since increasing the proportion of magnesium oxide reduces the thermal expansion of the first filament, increasing the proportion of magnesium oxide can improve the thermal shock resistance of the first filament. It has also been shown that increasing the proportion of magnesium oxide can improve the water resistance and / or acid resistance of the first filament, and that increasing the proportion of magnesium oxide promotes stress relaxation (cooling) of the glass. Furthermore, according to a purposeful embodiment, the first filament has a calcium oxide content of 20% by mass or less, preferably 10% by mass or less, and particularly preferably 8% by mass or less.

[0072] Experiments have shown that increasing the proportion of calcium oxide in the first filament significantly increases the tensile and / or flexural strength of the first filament. Furthermore, increasing the calcium oxide content can improve the surface tension and density of the inorganic starting material of the first filament in the liquid phase. Increasing the proportion of calcium oxide can also strengthen the tendency to crystallize, thereby improving the chemical resistance of the first filament.

[0073] In a particularly preferred embodiment, the ratio of the aluminum oxide content to the magnesium oxide content and / or calcium oxide content of the first filament is 1.0 or more, preferably 1.5 or more, and especially preferably 2.0 or more.

[0074] The experiment showed that the mechanical strength of the first filament could be improved by increasing the ratio of aluminum oxide content to magnesium oxide content and / or calcium oxide content.

[0075] Particularly preferred is that the first filament is a basalt filament.

[0076] The following terms are explained in relation to this.

[0077] "Basalt" is understood to refer to basalt, especially naturally occurring basalt that does not contain chemical additives.

[0078] "Basalt filament" is understood to be an inorganic filament that contains or consists of more than 90% basalt by mass.

[0079] Basalt fibers and their manufacturing processes are already known in the prior art, and therefore, the advantage can be gained that the production of cofilaments has already been sufficiently demonstrated, at least with respect to basalt fibers.

[0080] Furthermore, basalt already possesses many of the advantageous material proportions and / or material compositions described above, and therefore the labor involved in the production of the first inorganic filament can be advantageously reduced.

[0081] Furthermore, basalt is a relatively inexpensive and readily available raw material, which increases its potential for use in cofilaments and lowers its price. In particular, the energy required to manufacture basalt fibers is significantly less than that required for carbon fibers, glass fibers, or metal fibers.

[0082] In a particularly purposeful embodiment, the second filament has an aluminum content of 98% by mass or more, preferably 99% by mass or more, and especially preferably 99.5% by mass or more.

[0083] Aluminum is a metallic material that possesses particularly good thermal conductivity as well as very good electrical conductivity, and these properties can be utilized particularly advantageously in the cofilament proposed here.

[0084] Furthermore, aluminum exhibits excellent deformability, and by using aluminum as the metal, the flexibility of the cofilament can be greatly enhanced. This good deformability reduces the lateral load applied to the first filament by the deformation force of the second filament, thereby allowing the cofilament to be used more flexibly and advantageously extending its lifespan.

[0085] In addition, using aluminum provides a particularly synergistic effect, as it allows for better adhesion of the first filament to the aluminum, especially through chemical bonding with aluminum oxide, compared to other metals.

[0086] In addition, the relatively low melting point of aluminum, approximately 660°C, allows the first filament for producing the cofilament to have a relatively low glass transition temperature.

[0087] The excellent corrosion resistance of aluminum further enhances the flexibility of the cofilament in its potential specified usage environments.

[0088] The above values ​​regarding the aluminum content of the second filament should not be understood as strict limits, but rather should be explicitly noted that they may be higher or lower on an technical scale without departing from the embodiments of the invention described herein. In short, these values ​​provide a guideline for the magnitude of the aluminum percentage in the second filament proposed herein.

[0089] In an optional embodiment, the second filament has a copper content of 98% by mass or more, preferably 99% by mass or more, and particularly preferably 99.5% by mass or more. More preferably, the second filament has a copper content of 90% by mass or more, preferably 94% by mass or more, and particularly preferably 96% by mass or more.

[0090] Particularly preferable is that the second filament is substantially made of copper, and more preferably, the second filament is made of copper and contains only a relatively small amount of impurities.

[0091] Optionally, the first filament may have a circular or angular cross-section.

[0092] In particular, the first filament produced by the nozzle drawing method or spinning method may have a circular cross-section, especially an elliptical cross-section, or an angular cross-section, especially a square cross-section, a rectangular cross-section, a hexagonal cross-section, or a cross-section with n corners. Furthermore, a composite cross-sectional shape composed of at least two of the aforementioned basic shapes is also conceivable.

[0093] In that case, the shape of the second filament may be adapted to the shape of the first filament. If the first filament has a circular cross-section, the second filament may be crescent-shaped, hollow cylindrical, or similarly circular or elliptical. If the first filament has a rectangular shape, the second filament may be crescent-shaped, circular, or elliptical, partially surrounding the first filament, or a hollow body that completely surrounds the first filament. The same generally applies to shapes adapted to the first filament having a cross-section with n corners. In other words, the second filament has a shape corresponding to the first filament in the contact area with the first filament.

[0094] The second filament has a curved shape on the opposite side from the first filament, particularly created by the surface tension of the temporarily molten metal material during the manufacturing of the cofilament.

[0095] According to a preferred embodiment, the first filament has transverse extensions in the range of 3.5 μm or more and 25 μm or less, preferably in the range of 10 μm or more and 20 μm or less, and particularly preferably in the range of 11 μm or more and 18 μm or less.

[0096] Furthermore, the first filament has transverse extensions in the range of 11 μm or more and 16 μm or less, preferably in the range of 12 μm or more and 15 μm or less, and particularly preferably in the range of 12 μm or more and 14 μm or less.

[0097] The following terms are explained in relation to this.

[0098] "Lateral extension" is understood to mean the extension of a filament perpendicular to the longitudinal direction of a filament, particularly the extension of a first filament perpendicular to the longitudinal direction of a first filament, or the extension of a cofilament perpendicular to the longitudinal direction of a cofilament.

[0099] The aforementioned values ​​regarding the lateral extension of the first filament, in interaction with the similarly optimized geometry of the second filament, enable the development of optimal cofilament material properties for a wide range of applications.

[0100] The above values ​​regarding the lateral extension of the first filament should not be understood as strict limits, but rather it should be explicitly stated that they may be greater or less than those stated by technical standards without departing from the embodiments of the invention described herein. In short, these values ​​provide a guideline for the extent of the lateral extension of the first filament proposed herein.

[0101] Preferably, the second filament has a maximum wall thickness of 200 μm or less, preferably 160 μm or less, and particularly preferably 130 μm or less.

[0102] More preferably, the second filament has a maximum wall thickness of 100 μm or less, preferably 75 μm or less, and particularly preferably 50 μm or less. More preferably, the second filament has a maximum wall thickness of 30 μm or less, preferably 20 μm or less, and particularly preferably 15 μm or less. More preferably, the second filament has a maximum wall thickness of 10 μm or less, preferably 8 μm or less, and particularly preferably 5 μm or less. Particularly preferably, the second filament has a maximum wall thickness of 1 μm or less, preferably 0.1 μm or less, and particularly preferably 0.01 μm or less.

[0103] According to a purposeful embodiment, the second filament, which completely surrounds the first filament, has a wall thickness of 30 μm or less, particularly the maximum material thickness of the second filament, preferably a maximum wall thickness of 20 μm or less, and especially preferably a maximum wall thickness of 15 μm or less. More preferably, the second filament has a wall thickness of 8 μm or less, preferably a maximum wall thickness of 5 μm or less, and especially preferably a maximum wall thickness of 2 μm or less.

[0104] The following terms are explained in relation to this.

[0105] "Maximum wall thickness" is understood to refer to the maximum wall thickness of a filament in a specific cross-section, particularly the second filament.

[0106] Particularly preferably, the second filament has a maximum wall thickness of 0.2 μm or more, preferably 0.5 μm or more, and especially preferably 1 μm or more.

[0107] More preferably, the second filament has a maximum wall thickness of 1.5 μm or more, preferably 2 μm or more, and particularly preferably 3 μm or more.

[0108] Experiments have shown that the maximum wall thickness of the second filament described above allows for a very good compromise between the material requirements and the achievable properties of the cofilament, particularly with respect to its maximum and / or minimum values, and especially with respect to the lateral extension of the first filament which is optimized.

[0109] The above values ​​regarding the maximum wall thickness of the second filament should not be understood as strict limits, but rather it should be explicitly stated that they may be greater or less than those values ​​on an technical scale without departing from the embodiments of the invention described herein. In short, these values ​​provide a guideline for the range of maximum wall thickness of the second filament proposed herein.

[0110] According to a preferred embodiment, the cofilament has a maximum transverse extension in the range of 10 μm or more and 55 μm or less, preferably in the range of 10 μm or more and 40 μm or less, and particularly preferably in the range of 11 μm or more and 35 μm or less.

[0111] Furthermore, according to a preferred embodiment, the cofilament has a maximum lateral extension in the range of 11 μm or more and 30 μm or less, preferably in the range of 12 μm or more and 25 μm or less, and particularly preferably in the range of 12 μm or more and 20 μm or less. In particular, the cofilament has a maximum lateral extension in the range of 12 μm or more and 18 μm or less, preferably in the range of 13 μm or more and 17 μm or less, and particularly preferably in the range of 14 μm or more and 16 μm or less.

[0112] Particularly preferable is that the maximum lateral extension of the cofilament is 18 μm or less.

[0113] Regarding the application analysis, the aforementioned values ​​for the maximum lateral extension of the cofilament proved particularly advantageous for most applications.

[0114] Overall, this makes it possible to achieve particularly thin filaments that also possess novel material properties. Thin filaments enable the filtration of particularly fine particles.

[0115] The aforementioned values ​​for the maximum lateral extension of the cofilament should not be understood as strict limits, but rather should be explicitly noted as potentially exceeding or falling below these values ​​on an technical scale without departing from the embodiments of the invention described herein. Simply put, these values ​​provide a guideline for the magnitude of the range of maximum lateral extension of the cofilament proposed herein.

[0116] In an optional embodiment, the contact area between the first filament and the second filament is 1% or more of the circumference of the first filament, preferably 5% or more of the circumference of the first filament, and particularly preferably 10% or more of the circumference of the first filament.

[0117] Preferably, the contact area between the first filament and the second filament is 20% or more of the circumference of the first filament, preferably 30% or more, and particularly preferably 40% or more. More preferably, the contact area between the first filament and the second filament is 50% or more of the circumference of the first filament, preferably 60% or more, and particularly preferably 70% or more. Particularly preferably, the contact area between the first filament and the second filament is 80% or more of the circumference of the first filament, preferably 90% or more, and particularly preferably equal to 100% of the circumference of the first filament.

[0118] The following terms are explained in relation to this.

[0119] The "contact area" is understood to be the contact line between the first filament and the second filament.

[0120] Optionally, the contact area between the first filament and the second filament is 95% or less of the circumference of the first filament, preferably 90% or less, and particularly preferably 85% or less. Preferably, the contact area between the first filament and the second filament is 75% or less of the circumference of the first filament, preferably 65% ​​or less, and particularly preferably 55% or less.

[0121] The size of the contact area allows for an advantageous optimization of the compromise between the material requirements of the second filament and the material properties of the cofilament.

[0122] The aforementioned values ​​regarding the contact area between the first and second filaments should not be understood as strict limits, but rather should be explicitly noted as potentially exceeding or falling below these values ​​on an technical scale without departing from the embodiments of the invention described herein. In short, these values ​​provide a guideline for the size of the contact area between the first and second filaments proposed herein.

[0123] According to a second aspect of the present invention, a roving having cofilaments according to the first aspect of the present invention solves the above problem.

[0124] The following terms are explained in relation to this.

[0125] "Roving" is understood to refer to a bundle of multiple cofilaments arranged in strands, particularly a bundle of cofilaments arranged in parallel.

[0126] As is obvious, the advantages of the cofilament according to the first aspect of the present invention directly extend to rovings having the cofilament according to the first aspect of the present invention, as described above.

[0127] It should be explicitly stated that the subjects of the second embodiment are advantageously combinable with the subjects of the above embodiments of the present invention, and can be combined individually or cumulatively in any combination.

[0128] According to a third aspect of the present invention, a yarn having cofilaments according to the first aspect of the present invention solves the above problem.

[0129] The following terms are explained in relation to this.

[0130] "Yarn" is understood as a bundle of multiple cofilaments that have been made into strands, with the cofilaments of the yarn twisted around the long axis of the yarn. In particular, yarn has a ratio of yarn length to yarn diameter of 100 or more.

[0131] As is obvious, the advantages of the cofilament according to the first aspect of the present invention directly apply to the yarn having the cofilament according to the first aspect of the present invention, as described above.

[0132] It should be explicitly stated that the subject matter of the third embodiment can be advantageously combined with the subject matter of the preceding embodiments of the present invention, and can be combined individually or cumulatively in any combination.

[0133] In particular, short-cut fibers or long-cut fibers solve the above problems, and the short-cut fibers or long-cut fibers have a cut cofilament according to the first aspect of the present invention, a cut roving according to the second aspect of the present invention, or a cut yarn according to the third aspect of the present invention.

[0134] "Short-cut fibers" are understood to be fibers produced by cutting from a cofilament according to the first aspect of the present invention, a roving according to the second aspect of the present invention, or a yarn according to the third aspect of the present invention, and the short-cut fibers have a length of 6 mm or less.

[0135] "Long-cut fibers" are understood to be fibers produced by cutting from cofilaments according to the first aspect of the present invention, rovings according to the second aspect of the present invention, or yarns according to the third aspect of the present invention, and long-cut fibers have a length of 60 mm or less and longer than 6 mm.

[0136] According to a fourth aspect of the present invention, a semi-finished product comprising a cofilament according to the first aspect of the present invention and / or a roving according to the second aspect of the present invention solves the above problem.

[0137] The following terms are explained in relation to this.

[0138] "Semi-finished products" or "semi-finished textiles" are understood to be raw materials pre-fabricated from cofilaments, particularly textiles, where the pre-fabricated raw materials have cofilaments of a basic geometric shape. Textiles or textile semi-finished products are fiber-based and may be nonwoven fabrics in particular. Textiles or textile semi-finished products are fiber-based and may be knitted fabrics in particular, especially knitted fabrics or knitted cloths. Textiles or textile semi-finished products are fiber-based and may be systems of drawn yarns, particularly mats or tapes. Textiles or textile semi-finished products are fiber-based and may be systems of crossed yarns, particularly woven fabrics or braided fabrics.

[0139] In particular, semi-finished products are understood to be short-cut fibers or long-cut fibers, and short-cut fibers or long-cut fibers have cut cofilaments according to the first aspect of the present invention, roving according to the second aspect of the present invention, or cut yarn according to the third aspect of the present invention.

[0140] Furthermore, nonwoven fabrics are understood to be semi-finished products composed of short-cut fibers and / or long-cut fibers, the short-cut fibers and / or long-cut fibers having cut cofilaments according to the first aspect of the present invention, or cut rovings according to the second aspect of the present invention, or cut yarns according to the third aspect of the present invention.

[0141] A semi-finished product comprising a cofilament according to a first aspect of the present invention can be an excellent substitute for a solid metal plate for shielding against electromagnetic waves, thereby dramatically reducing the weight of the shield. This is particularly applicable in the field of mobility.

[0142] As described above, it is obvious that the advantages of the cofilament according to the first aspect of the present invention directly apply to the semi-finished product having the cofilament according to the first aspect of the present invention.

[0143] It should be explicitly stated that the subjects of the fourth aspect can be advantageously combined with the subjects of the above-described aspects of the present invention, and can be combined individually or cumulatively in any combination.

[0144] According to a fifth aspect of the present invention, the use of a cofilament according to the first aspect of the present invention for conducting electric current and / or heat and / or shielding electromagnetic waves and / or as a component of an antenna solves the above problems. In particular, when a cofilament is used in an antenna, the particularly good conductivity of the cofilament is advantageous in that the cofilament can advantageously derivate electromagnetic pulses from the antenna, especially in the case of low-frequency electromagnetic pulses. This makes it possible to effectively protect the antenna from electromagnetic pulses.

[0145] A cofilament according to a first aspect of the present invention has advantages, in particular, with respect to its electrical and / or thermal conductivity, and / or its tensile strength, and / or its temperature resistance, and / or its chemical resistance, and / or its porosity, and / or its drape, and / or its antiviral effect and / or its flame retardancy.

[0146] These advantages can be used in a wide variety of applications to improve the functionality of products. In particular, here specifically, battery housings, especially in textiles, especially smart textiles, especially ski socks and / or winter jackets, conductive paths for sensors and / or actuators and / or power supply connections, and / or electromagnetic shielding for smart textiles, especially ponchos and / or maternity clothes and / or work clothes, and / or filters, especially heavy oil filters, and / or improving filtration efficiency especially in air filters, and / or electromagnetic shielding wallpaper for CT rooms and / or EMP protection, and / or electromagnetic shielding curtains, especially for EMP protection and / or server rooms. Possible uses of cofilaments include as reinforcing fibers for and / or metal articles, particularly aluminum rims and / or aluminum bodies, and / or aluminum die-cast parts and / or similar materials, and / or as composite additives for fiber-reinforced concrete and / or organoboards and / or similar materials, and / or antiviral clothing and / or protective masks and / or fire-fighting clothing and / or similar materials, and / or sensor systems for antennas and / or structural monitoring and / or measurement detection, and / or dipoles, particularly antennas and / or decoys, and / or for shielding, particularly insulators and / or reflectors.

[0147] As is obvious, the advantages of the cofilament according to the first aspect of the present invention directly relate to the use of the cofilament according to the first aspect of the present invention, as described above.

[0148] It should be explicitly stated that the subjects of the fifth aspect of the invention are advantageously combinable with the subjects of the above aspects of the invention, and can be combined individually or cumulatively in any combination.

[0149] According to a sixth aspect of the present invention, a method for producing a cofilament according to the first aspect of the present invention solves the above problem, and the method comprises the following steps, namely - A step of forming a first filament by nozzle stretching or spinning, - The process includes at least partially coating the first filament with the second filament.

[0150] Here, a method for producing advantageous cofilaments according to a first aspect of the present invention is proposed.

[0151] In particular, in the method proposed here, the coating of the first filament with the second filament is carried out by bringing the first filament into contact with molten metal, and the first filament is guided along its longitudinal direction over the contact point. As a result, the molten metal adheres to the first filament, is carried together with it in the direction of its movement by the first filament, transitions to a solid aggregated state, and forms a second filament that adheres to the first filament, especially a second filament that comes into contact with the first filament.

[0152] In that case, the first filament can be separated from the molten material before coating with the second filament.

[0153] In particular, the first filament is brought into contact with the molten metal substance, especially after the first filament has fallen below its glass transition temperature, and moreover, the first filament has a temperature higher than the melting temperature of the metal substance at the time of contact. Contact between the inorganic first filament and the molten metal is possible because the contact time between the inorganic first filament and the molten metal substance is in the range of a few milliseconds. In particular, the short contact time proposed here makes it possible to ensure that the material properties of the inorganic filament are not impaired by the temperature of the molten metal substance.

[0154] In that case, it is proposed to connect the first filament to the metallic material with a contact lip. Since the metallic material is in a molten liquid state in the region of the contact lip, it is conceivable to form the lip from a material that exists as a solid at a temperature higher than the melting point of the metallic material. In particular, in this case, a lip made of ceramic wetted with the metallic material can be considered, thereby bringing the first filament into contact with the metallic material adjacent to the lip.

[0155] In a purposeful embodiment, the lip may vibrate during the manufacturing of the cofilament. This can advantageously improve the continuous flow behavior of the molten metal material, thereby making the layer thickness of the second filament smaller and / or more uniform and / or the maximum wall thickness of the second filament more uniform.

[0156] The experiment demonstrated that cofilaments can be manufactured at speeds particularly in the range of 500 m / min to 4,000 m / min, preferably in the range of 2,500 m / min to 1,300 m / min, and especially preferably in the range of 900 m / min to 1,500 m / min. This advantageously improves productivity compared to conventional methods, and the resulting fibers can be manufactured at a lower cost.

[0157] In particular, the cofilament is wound after the first filament is at least partially coated with the second filament.

[0158] It should be explicitly stated that the subjects of the sixth aspect of the invention are advantageously combinable with the subjects of the above aspects of the invention, and can be combined individually or cumulatively in any combination.

[0159] Further advantages, details, and features of the present invention will become apparent from the embodiments described below. [Brief explanation of the drawing]

[0160] [Figure 1]This figure schematically shows a first embodiment of the cofilament. [Figure 2] This figure schematically shows a second embodiment of the cofilament. [Figure 3] This figure schematically shows a longitudinal cross-sectional view of the first embodiment of the cofilament. [Figure 4] This figure schematically shows a longitudinal cross-sectional view of a second embodiment of the cofilament. [Figure 5] This figure schematically shows a third embodiment of the cofilament. [Figure 6] This figure schematically shows a fourth embodiment of the cofilament. [Figure 7] This figure schematically shows a fifth embodiment of the cofilament. [Figure 8] This is a schematic diagram showing the first embodiment of the yarn. [Figure 9] This is a schematic diagram showing a second embodiment of the yarn. [Modes for carrying out the invention]

[0161] In the following description, the same reference numerals indicate the same component or feature; therefore, the description of a component given for one figure is also valid for other figures, avoiding repetition of descriptions. Furthermore, individual features described in relation to one embodiment can also be used separately in other embodiments.

[0162] The cofilament 10 according to the first embodiment shown in Figures 1 and 3 substantially consists of a first filament 13 made from an inorganic material and a second filament 12 made from a metallic material.

[0163] The first filament 13 has a glass transition temperature of 4000°C or higher.

[0164] The second filament 12 is formed in a crescent shape and comes into contact with the first filament 13.

[0165] The cofilament 10 according to the second embodiment shown in Figures 2 and 4 consists substantially of a first filament 13 made from an inorganic material and a second filament 12 made from a metallic material.

[0166] The second filament 12 forms a homogeneous outer layer around the first filament 13, particularly having a certain thickness.

[0167] In the third embodiment shown in Figure 5, the cofilament 10 is formed by a relatively small contact area between the first filament 13 and the second filament 12, thereby arranging the individual filaments 12 and 13 side by side in pairs.

[0168] The cofilament 10 according to the fourth embodiment in Figure 6 has three first filaments 13 connected to one another by a common second filament 12. The cofilament 10 according to the fourth embodiment is obtained by fusing the second metal filaments 12 of the three cofilaments 10 of the first and / or second and / or third embodiments.

[0169] The cofilament 10 according to the fifth embodiment in Figure 7 has three first filaments 13 connected to each other by a common second filament 12. In particular, this can be obtained as in the cofilament 10 of the fourth embodiment.

[0170] The yarn 20 according to the first embodiment in Figure 8, or the yarn 20 according to the second embodiment in Figure 9, consists of a plurality of cofilaments 10 according to the first and / or second and / or third and / or fourth and / or fifth embodiments. [Explanation of symbols]

[0171] 10 cofilaments 12. Second filament 13. First filament 20 yarns

Claims

1. A cofilament (10) comprising a first filament (13) and a second filament (12), wherein the first filament (13) and the second filament (12) are physically and / or chemically connected to each other to form the cofilament (10), the first filament (13) is made of an inorganic material, the first filament (13) has a glass transition temperature of 400°C or higher, the first filament (13) is a basalt filament, the second filament (12) is made of a metallic material, the second filament (12) is in contact with the first filament (13), and the contact area between the first filament (13) and the second filament (12) is 5% or more of the circumference of the first filament (13).

2. The cofilament (10) according to claim 1, characterized in that the first filament (13) has a glass transition temperature of 660°C or higher, preferably 800°C or higher, and particularly preferably 1,000°C or higher.

3. The cofilament (10) according to any one of claims 1 or 2, characterized in that the first filament (13) has a bound oxygen content of 30% by mass or more, preferably 40% by mass or more, and particularly preferably 44% by mass or more.

4. The cofilament (10) according to any one of claims 1 to 3, characterized in that the first filament (13) has a silicon dioxide content of 45% by mass or more, preferably 50% by mass or more, and particularly preferably 55% by mass or more.

5. The cofilament (10) according to any one of claims 1 to 4, characterized in that the first filament (13) has an aluminum oxide content of 12% by mass or more, preferably 14% by mass or more, and particularly preferably 16% by mass or more.

6. The cofilament (10) according to any one of claims 1 to 5, characterized in that the first filament (13) has a boron trioxide content of 0.5% by mass or less, preferably 0.1% by mass or less, and particularly preferably 0.01% by mass or less.

7. The cofilament (10) according to any one of claims 1 to 6, characterized in that the second filament (12) has an aluminum content of 98% by mass or more, preferably 99% by mass or more, and particularly preferably 99.5% by mass or more.

8. The cofilament (10) according to any one of claims 1 to 7, characterized in that the first filament (13) has a circular or angular cross-section.

9. The cofilament (10) according to any one of claims 1 to 8, characterized in that the first filament (13) has transverse extension in the range of 10 μm or more and 25 μm or less, preferably in the range of 10 μm or more and 20 μm or less, and particularly preferably in the range of 11 μm or more and 18 μm or less.

10. The cofilament (10) according to any one of claims 1 to 9, characterized in that the second filament (12) has a maximum wall thickness of 30 μm or less, preferably 20 μm or less, and particularly preferably 15 μm or less.

11. The cofilament (10) according to any one of claims 1 to 10, characterized in that the second filament (12) has a maximum wall thickness of 0.2 μm or more, preferably 0.5 μm or more, and particularly preferably 1 μm or more.

12. The cofilament (10) is characterized in that it has a maximum transverse extension in the range of 10 μm or more and 55 μm or less, preferably in the range of 10 μm or more and 40 μm or less, and particularly preferably in the range of 11 μm or more and 35 μm or less, according to any one of claims 1 to 11.

13. The cofilament (10) according to any one of claims 1 to 12, characterized in that the contact area between the first filament (13) and the second filament (12) is 10% or more of the circumference of the first filament (13), preferably 15% or more of the circumference of the first filament (13), and particularly preferably 20% or more of the circumference of the first filament (13).

14. The cofilament (10) according to any one of claims 1 to 13, characterized in that the contact area between the first filament (13) and the second filament (12) is 95% or less of the circumference of the first filament (13), preferably 90% or less of the circumference of the first filament (13), and particularly preferably 85% or less of the circumference of the first filament (13).

15. A roving comprising the cofilament (10) according to any one of claims 1 to 14.

16. A yarn comprising the cofilament (10) according to any one of claims 1 to 14.

17. A semi-finished product comprising the cofilament (10) according to any one of claims 1 to 14.

18. Use of the cofilament (10) according to any one of claims 1 to 14 for conducting electric current and / or conducting heat and / or shielding electromagnetic waves and / or as a component of an antenna.

19. A method for producing a cofilament (10) according to any one of claims 1 to 14, comprising the following steps: - A step of forming a first filament (13) by nozzle stretching or spinning, A method comprising the step of coating a first filament (13) with a second filament (12).

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