DE102012107911A1 - Precious metal wire containing, in particular textile fabric - Google Patents

Abstract

Known textile fabrics contain precious metal wire or they consist entirely of it. In order to achieve a high bending and tensile strength with high flexibility of the sheet, it is proposed according to the invention that the noble metal wire is formed as a noble metal cord comprising a plurality of strands or a plurality of noble metal strands or a combination of strands and precious metal strands each placed around each other and / or twisted around each other.

Description

The invention relates to a precious metal wire containing, in particular textile fabric.

State of the art

The use of precious metal wire for the production of knitwear, especially nets made of noble metal-containing wires, has long been known for catalyst applications. For example, catalyst networks of platinum-rhodium wires with thicknesses between 60 and 120 microns are used for the catalysis of ammonia combustion for nitric acid production. The catalytic effect depends on the size of the freely accessible noble metal surface, but at the same time a gas stream flowing through the catalyst network should encounter the lowest possible flow resistance. The density of the network with precious metal wire and the wire thickness are relevant parameters here.

The known catalyst networks are made of the noble metal wires, for example by machine weaving, knitting or knitting. In these production methods, the bending and tensile strengths and the ductility of the precious metal wires play a limiting role. Thus, for example, for entangling wires of certain platinum-rhodium, platinum-palladium-rhodium, palladium-nickel, palladium-copper and palladium-nickel-copper alloys, only noble metal wires with diameters between 50 to 120 μm and tensile strengths between 900 and 1050 N / mm ² . Thick precious metal wire reduces the flexibility of the network.

Metal wires or metal threads are also used for a variety of other applications. For example, in fuel cells gas diffusion layers of textile fabric are used, which should have a high electrical conductivity and catalytic properties. In this case, wires made of platinum or ruthenium can be used to produce the tissue.

For the production of flexible shielding against electromagnetic fields - such as in packaging material or in garments - it is known to inject copper wires in electrically conductive, textile fabrics as electrical contacts, weave, act or einzunadeln. The metal threads used must be very thin to ensure the flexibility of the textile. They are therefore almost invisible.

In jewelery production, precious metal wire is used to form decorative elements in textiles and ribbons. For this purpose, a certain thickness of the decorative element is required in order to achieve visual recognition and visual decorative effect. However, thick threads or wires can impair the mechanical properties of the fabric, in particular its flexibility. It is also known to admit metal threads as a mark of authenticity or security in banknotes or documents.

In the production of the respective fabric as well as in its specific application, high forces can act on the metal wire. Therefore, there is always a special focus on the bending and tensile strength of the wire, but also on the flexibility. However, these are conflicting requirements; It is difficult to meet high demands on strength and flexibility at the same time.

Technical task

The invention has for its object to provide a sheet containing or consisting of precious metal wire, and meets the high demands on strength and flexibility.

General presentation of the invention

This object is achieved in terms of the aforementioned sheet structure according to the invention that the noble metal wire is formed as a noble metal cord comprising a plurality of strands or a plurality of noble metal strands or a combination of strands and precious metal strands each placed around each other and / or rotated around each other are.

Under a strand here is usually a loose but frictional or positive composite of at least two, preferably at least four and more preferably at least seven precious metal strands understood. These noble metal strands are either helically wound around each other and / or twisted around each other, as is well known in the wire and rope manufacturing.

The noble metal cord comprises a plurality, preferably at least four, particularly preferably at least seven such strands, which are combined into a bundle in which the strands are frictionally or positively connected, or comprises precious metal individual wires or a combination of strands and noble metal strands. Individual wires that are each placed around each other and / or twisted around each other. Particularly preferably, the noble metal cord comprises a bundle of at least two strands, which are each formed from a plurality of precious metal individual wires placed around one another and / or twisted around one another.

Such a noble metal wire in bundle form - here referred to as precious metal cord - shows a high compared to a noble metal single wire with the same radial cross-sectional area tensile strength with higher flexibility - that is, lower flexural rigidity. These properties also affect the fabrics made from this precious metal cord or those containing the precious metal cord in the same way. This means that the fabric is more flexible and generally also stronger with the same noble metal content compared to a single wire. In addition, with the same precious metal content, the cord is thicker and looks nobler than a single wire.

The precious metal cord is made of precious metal or it contains a significant proportion (> 50 wt .-%) of precious metal. By "precious metal" is meant the elements of the platinum group: Os, Ir, Pt, Ru, Rh, Pd and Ag, Au. The flexibility-preserving or increasing effect is also expected in metal cords of other metals, such as of Cu, Fe, Ni, Ti, Co, Cr, Zr, Nb, Mo, Ta, W, Al and alloys based on these metals, wherein especially non-ferrous metals and stainless steel are mentioned. A proportion of such metal cords is therefore harmless to the inventive sheet.

The sheet according to the invention is flat or it extends in three spatial directions and can be made of fibers or wires or consist of a flat-shaped workpiece, in which one or more precious metal cords are embedded. Because of their low residual stress these cords do not affect the geometric shape of the sheet or little, so that this retains the desired flexibility and flexibility, even with a large cross section of the precious metal cord.

In a preferred embodiment of the noble metal cord, the strands - as well as the individual wires - either helically wound around each other and / or twisted around each other, as known from the wire rope or rope production.

In the bundle, in addition to the strands mentioned, one or more precious metal individual wires can also be incorporated into the noble metal cord.

In a particularly preferred embodiment, it is provided that the noble metal cord consists of exactly seven laid around each other and / or twisted strands, which are each formed from exactly seven placed around each other and / or twisted around each precious metal individual wires.

Stainless steel wires are known as "7 × 7 Cord" or "7 × 7 Strand".

In view of the highest possible flexibility of the sheet and a preferably large surface area of the noble metal in catalyst applications, the precious metal individual wires used to produce the noble metal cord are as thin as possible and advantageously have a diameter in the range from 25 μm to 50 μm, particularly preferably 30 μm to 40 μm.

In this context, a precious metal cord has proven particularly useful if it has a radial cross-section envelope which has a diameter in the range of 250 microns to 500 microns, preferably in the range of 300 microns to 400 microns.

The fabric is composed, for example, of construction, functional and / or decorative threads which form a woven, knitted, knitted, knitted, braided, crocheted, felted or weft-bonded or non-woven fabric.

The construction threads are, for example, the stitch-forming threads of knitted or crocheted fabrics, the warp or weft threads on fabrics, or any joining or finishing seams.

Functional threads or ornamental threads have a special optical, chemical or physical effect, which may differ from that of the other threads, such as in their electrical conductivity, the catalytic effect or their aesthetic appearance. Jewelery threads can also be used, for example, to produce visible seams that fulfill a pure design function.

In this case, all or at least part of the construction, functional or jewelry threads are formed from the precious metal cord.

An optical insert made of precious metal unfolds its aesthetic effect in the fabric only with sufficient thickness. With the thickness but also increase internal stress and bending stiffness, which can lead to undesirable deformation of the fabric. This disadvantage avoids the use of the noble metal cord according to the invention, since these produce a low residual stress due to their high flexibility even at thicknesses which ensure adequate visual recognition and decorative effect. Furthermore, with the same precious metal weight, a higher value is achieved by the larger diameter, which saves material costs in comparison with a wire of corresponding thickness.

The sheet is formed in a preferred embodiment as a fabric in which at least a portion of the construction or functional threads made of glass, ceramic, basalt, carbon, natural fibers or synthetic fibers or combinations thereof.

The inorganic fibers, such as the glass, ceramic, basalt or carbon fibers explicitly mentioned above, are often brittle and may be provided with a plastic sheath to facilitate processing to the fabric. Irrespective of this, when using the noble metal cord together with such fibers, it is generally advantageous to finally embed the textile fiber composite in a plastic matrix or to subsequently provide it with a plastic lacquer layer. Particularly suitable for this purpose are sprayable plastics such as epoxy resins, polyetheretherketone (PEEK), polyoxymethylene (POM) or styrene-acrylonitrile (SAN).

Carbon fibers are commercially available in different diameters. They consist of single fibers with diameters of 5 to 8 μm, of which 1000 are combined into strands - so-called "rovings". For use with precious metal cords according to the invention Rowing types of 1K to 12K are particularly suitable, where K stands for 1000 individual fibers.

In a particularly advantageous embodiment of the sheet according to the invention fibers of carbon and / or glass with precious metal cord form a flat textile composite.

This textile composite is characterized by a particularly high strength and flexibility. It can be provided as a dry fiber composite semi-finished product, for example in roll form.

For applications in which it depends on a higher flexural rigidity or dimensional accuracy of the fabric, such as in technical molded parts, the textile composite may also be impregnated with a polymerizable, flowable matrix material, such as a resin.

After shaping and curing of the matrix material, the desired molded part is obtained.

Alternatively or additionally, the textile composite can also be coated with a film of a polymerizable matrix material.

After forming and curing, the film forms a dense, smooth surface layer on the fiber composite.

Ideally, for ease of processing, the diameters of the carbon and / or glass fibers and the noble metal cord are the same. Deviations of the diameters by a maximum of 20% - related to the larger of the two diameters - are acceptable.

Textile composites of noble metal cord and carbon fibers according to the invention have proven particularly useful.

The natural fibers or synthetic fibers, which may also be (spun) threads, preferably consist of linen, hemp, jute, sisal, coconut, cotton, wool, animal hair, silk, viscose, modal, cupro, acetate, polyester, Polyamide, polyimide, aramid, polyacrylonitrile, polytetrafluoroethylene, polyethylene, polypropylene, polyvinyl chloride or polyurethane.

In such a fabric, which is made of different fiber or wire materials, often results in the problem of warping already during manufacture or only in the course of proper use, if the fibers or wires differ in their flexibility and flexural rigidity too much. The incorporation of rigid wires also suffers the flexibility of the entire fabric. These difficulties avoid the invention, since the flexibility and flexural rigidity of the precious metal cord can be easily adapted by the bundle shape and size to the given requirements. In addition, the precious metal cord shows a high flexibility even with a comparatively large cross-section and thus produces a low residual stress within the textile product. As a result, it can also be reproducibly processed into warp-free, flexible textile products in conjunction with fiber or wire materials of a completely different kind.

The fabric is executed in a preferred embodiment as a garment.

The precious metal cord forms only part of the textile and serves, for example, as a functional or decorative element in the form of a thread or a connecting, decorative or finishing seam.

Alternatively, the sheet may also be formed as paper, leather, fur, plastic or fiber-reinforced carbon, in which the precious metal cord is stored as a functional or decorative element.

The sheet is in this case as a flat or three-dimensionally shaped workpiece made of a flexible base material, in which one or more precious metal cords are incorporated. Also In this type of sheet, the problem of warping or loss of flexibility already discussed above arises when wires are incorporated which have a significantly different bending stiffness than the base material. The flexibility and bending stiffness of the precious metal cord creates a low residual stress within the fabric and can be easily adapted to the given requirements by the bundle shape and size.

Here, the precious metal cord, for example, functions to ensure the security and authenticity of documents, such as certificates or banknotes or in terms of meeting visual and aesthetic requirements, such as markings or visually appealing deposits in flat construction parts or as a conclusion or decorative stitching on leather or fur products.

embodiment

The invention will be explained in more detail with reference to embodiments and a drawing. This shows in a schematic representation

1 a 7 × 7 precious metal cord according to the invention in a radial cross section,

2 to 4 other particularly suitable cross sections of precious metal cords,

5 to 12 Examples of textile fabrics with embedded therein precious metal cords with different shape and function,

13 a housing cover for a mobile phone, in which jewelery threads made of precious metal cord are incorporated, and

14 an embodiment of the sheet according to the invention in the form of a leather case with a connecting seam and an emblem of precious metal cord.

In the 1 shown precious metal cord 1 consists of 7 × 7, so 49 individual wires 2 made of 18 K 5 N red gold, each with an outer diameter of 35 μm. In each case seven of these individual wires 2 are in hexagonal arrangement (with internally centered precious metal wire 2a ) to a strand 3 summarized and seven of the strands 3 are in turn also in a hexagonal arrangement (with internally centered stranded wire 3a ) to the precious metal cord 1 bundled.

The production of the precious metal cord 1 takes place by means of a usual Verlitzmaschine, by seven precious metal single wires 2 withdrawn by means of an extractor from coils and with an adjustable lay length by means of a rotor to a strand 3 be twisted around each other. Seven sections of the strand thus produced 3 become the precious metal cord in the same way 1 bundled.

The envelope enclosing the cross section 4 the precious metal cord thus produced 1 has a diameter of 330 μm. Based on this cross section shows the precious metal cord 1 excellent flexibility combined with high tensile strength.

2 shows a 1 × 7 noble metal cord according to the invention in a radial cross section, 3 a 1 × 19 precious metal cord and 4 a 3 × 7 precious metal cord.

The cross-sectional view of 2 schematically shows a precious metal cord with 1 × 7 construction. This consists of seven helically stranded individual wires. It is a particularly simple construction of a precious metal cord.

3 schematically shows a 3 × 7 construction of a precious metal cord consisting of 21 Precious metal strands. In each case seven of these individual wires 2 are in hexagonal arrangement (with internally centered precious metal wire 2a ) to a strand 3 summarized and three of these strands 3 are in turn bundled to the precious metal cord.

4 schematically shows a precious metal cord with 1 × 19 construction. This consists of 19 Precious metal strands 2 in a hexagonal arrangement (with internally centered precious metal wire 2a ) to a strand 3 are summarized.

In the 5 to 12 schematically fabric types are shown, for a precious metal cord in the context of the invention is advantageously used with other textile threads. The precious metal cord 51 is shown in all figures in dark gray hatching, the other textile threads 52 in white color. The precious metal cord 52 is used as a weft thread or as a warp thread, or as shown in the figures on the right side, as weft and warp thread. The weft direction S and the warp direction K is the same in all examples and indicated by the direction arrows K and S.

5 schematically shows a first embodiment of a simple canvas fabric with precious metal cord 51 as weft and chain of other threads 52 ,

6 schematically shows a second embodiment of a simple canvas fabric with precious metal cord 51 partly as a weft thread and as a warp thread, mixed with other threads.

7 schematically shows a fabric 4 × 4 twill weave with precious metal cord 51 as weft and chain of other textile threads.

8th also shows a 4 × 4 twill weave fabric with precious metal cord 51 as a weft thread and as a warp thread, mixed with other threads.

9 schematically shows a fabric 2 × 2 twill weave with precious metal cord 51 as weft and chain of other threads.

10 also shows a 2 × 2 twill weave with precious metal cord 51 as a weft thread and as a warp thread, mixed with other threads.

11 schematically shows a e modification of the in 9 shown fabric in 2 × 2 twill weave. The precious metal cord 51 serves as a weft thread, but it rests on one side of the fiber bundle in the chain. The warp threads are made of carbon fibers 52 ,

12 corresponds to a modification of the in 10 shown fabric in 2 × 2 twill weave. The precious metal cord 51 serves as a warp and weft thread, but it rests on one side of the fiber bundle in the chain. The warp threads are made of carbon fibers 52 ,

The following are some examples of the use of precious metal cords in the context of producing a fabric according to the invention specified.

example 1

The precious metal cord 1 is used as a warp in a net-like fabric whose weft threads consist of carbon fibers. The precious metal cord 1 gives the net a high strength with low bending stiffness.

Example 2

The low bending stiffness makes itself in another use of the precious metal cord according to the invention 1 advantageous noticeable, namely when used as jewelry or functional element in a textile garment, such as a jacket made of synthetic fiber material, in which the precious metal cord 1 is incorporated.

Example 3

13 schematically shows a housing cover 110 for a mobile phone. This is a flat, slightly curved component with a bulge 114 executed. The housing cover 110 consists of a mixed fabric of interwoven carbon fibers 111 and precious metal cords 112 made of gold wires with a single wire diameter of 35 μm, which are stranded together to a 7 × 7 beach.

To produce the housing cover, the mixed fabric is in a polymerizable epoxy plastic resin 113 embedded, which completely fills the fiber space and which is transparent after curing.

After curing, a dimensionally stable component is obtained, which still has a certain elastic flexibility. In the mixed fabric produced according to the fabric type "canvas" form the black carbon fibers 111 and the gold-colored precious metal cords 112 a visually appealing stripe pattern.

Example 4

A clock dial shows a border and markers for the hour display. It consists of a fiber composite plastic component made of carbon fiber fabric, in which red gold cords are woven. These consist of gold wires with a diameter of 50 microns, which are bundled in the form of a 3 × 7 strand. The pink gold cords form the border and hour markers of the dial. The mixed fabric of carbon fibers and red gold cords is impregnated with transparent epoxy resin and cured.

Example 5

A spectacle frame consists of a fiber composite plastic interwoven precious metal cord made of a silver alloy and aramid fibers (Kevlar ^® ). The silver cords have a diameter of 40 microns and are stranded to a 7 × 7 beach. The fabric of silver cord and aramid fiber is embedded in a transparent epoxy plastic resin as described in Example 4. The silver cord forms an easily recognizable, decorative emblem in the brackets of the glasses frame.

Example 6

A trim strip for use in the automotive interior forms a flat, curved component. It consists of a fiber composite plastic, which is composed of a 7 × 7 gold cord of gold fibers with a fiber diameter of 35 microns and carbon fibers and synthetic resin. The mixed fabric of gold fiber cord and carbon fiber is embedded in a plastic resin, as described in Example 4. In the mixed fabric produced according to the fabric type "twill", the gold fiber cords form a visually appealing herringbone pattern.

Example 7

In the same manner as described in Example 4 for a watch dial, an instrument panel for a motor vehicle is made of a fiber composite plastic member which is woven from a carbon fiber fabric into which platinum cords are woven. These consist of platinum wires with a diameter of 25 microns, which are bundled as a 7 × 7 beach. The platinum cords form borders and markings of instrument displays. The mixed fabric of carbon fibers and platinum cords is soaked with transparent plastic resin and cured.

Example 8

14 schematically shows a leather case 120 , consisting of a top part 121 and a bottom part sewn with it 122 , each made of black leather. The connection seam 123 is made of a precious metal cord made of 18K pink gold 5N. This consists of individual wires with a diameter of 35 microns, which are stranded together to form a 7 × 7 beach.

The visible seam 123 made of precious metal cord stands out from the black leather decorative. Also, in the case shell 121 with the same cord an emblem 124 eingehäkelt.

Example 9

From a tubular semi-finished a lighter holder is made. The semi-finished product consists of a fiber composite of palladium and copper cord. Both the palladium cord and the copper cord each consist of individual wires with a diameter of 50 microns, which are bundled into a 3 × 7 beach). Precious metal cord and copper cord form a mixed fabric of metal strips of different colors that form a decorative pattern.

The resulting tubular semi-finished product is supplied on a roll and bent in the green state - before curing of the synthetic resin - to form a tubular sleeve over a mandrel. The sleeve obtained after curing of the resin matrix has a dense, smooth surface and forms a lighter holder in which alternate strips of silver-colored palladium and reddish-golden copper in a visually appealing manner.

Claims (17)

Sheet containing precious metal wire, characterized in that the precious metal wire is a precious metal cord ( 1 ) is formed, the plurality of strands ( 3 ) or several precious metal individual wires ( 2 ) or a combination of strands and noble metal strands which are each laid around each other and / or twisted around each other. Sheet according to Claim 1, characterized in that the strands ( 3 ) of a plurality, preferably of at least four, more preferably of at least seven mutually placed and / or twisted around each other precious metal individual wires ( 2 ) are formed. Sheet according to claim 1 or 2, characterized in that the precious metal cord ( 1 ) at least two, preferably at least four, particularly preferably at least seven laid around and / or twisted strands (US Pat. 3 ). Sheet according to claim 3, characterized in that the precious metal cord ( 1 ) of seven laid and / or twisted strands ( 3 ), which in each case again consist of seven precious metal individual wires which are placed around one another and / or twisted around one another ( 2 ) are formed. Sheet according to one of the preceding claims, characterized in that the precious metal individual wires ( 2 ) have a diameter in the range of 25 microns to 50 microns, preferably from 30 to 40 microns. Sheet according to one of the preceding claims, characterized in that the precious metal cord ( 1 ) enveloping its radial cross-section ( 4 ) having a diameter in the range of 250 microns to 500 microns, preferably in the range of 300 microns to 400 microns. Sheet material according to one of the preceding claims, characterized in that it is produced as a construction, functional and / or decorative threads fabric, knitted fabric, knitted fabric, embroidery, braid, crochet, a felt or Walkware or a nonwoven. Sheet material according to claim 7, characterized in that at least a part of the construction, functional or decorative threads is formed from the precious metal cord. Sheet material according to claim 7 or 8, characterized in that at least a part of the construction or functional threads made of glass, from Ceramics, carbon, natural fibers or synthetic fibers or combinations thereof. Sheet according to claim 9, characterized in that fibers of carbon and / or glass with precious metal cord ( 1 ) form a flat textile composite. Fabric according to claim 10, that the textile composite is impregnated with a polymerizable, flowable matrix material. Sheet material according to claim 11 or 12, that the textile composite is covered with a film of a polymerizable matrix material. A fabric according to any one of claims 10 to 12, wherein the textile composite is a fabric and that the fibers of the first type are carbon fibers. Fabric according to one of claims 10 to 13, that the textile composite is present as a web material on a roll. A fabric according to claim 9, characterized in that the natural fibers or synthetic fibers of linen, hemp, jute, sisal, coconut, cotton, wool, animal hair, silk, viscose, modal, cupro, acetate, polyester, polyamide, polyimide, aramid, polyacrylonitrile, Polytetrafluoräthylen, polyethylene, polypropylene, polyvinyl chloride or polyurethane. A fabric according to claim 9 or 15, characterized in that the fabric is a garment. Sheet according to one of claims 1 to 6, characterized in that it is made of paper, leather, fur, plastic or fiber-reinforced carbon, in which the precious metal cord is included as a functional or decorative element.

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