Flexible Metal Polymer Composites

Abstract

The invention relates to a flexible polymer composite containing metal particles, to the method for producing said composite, and to the uses of said composite.

Claims

1. A polymer composite comprising: a binder, preferably of elastomer type, a metal powder, preferably copper, comprising 30% by mass of grains with a diameter greater than 45 μm, dispersed in the binder; characterized in that said composite has a Young's modulus (E) less than 5 GPa.

2. The composite as claimed in claim 1 characterized in that the Young's modulus (E) is less than 1 GPa, preferably less than 0.5 GPa.

3. The composite as claimed in claim 1 or 2 characterized in that the binder is an organic or inorganic binder, or a mixture of both.

4. The composite as claimed in any one of claims 1 to 3 characterized in that the binder is selected from a plastic, a latex, a rubber, a polyethylene, polypropylene, polyurethane, an epoxy polymer, vinyl ester, aqueous-phase polymers, Nylons®, polyamides, polycarbonates, polystyrenes, polymethylmethacrylate, a silica polymer such as a silicone, polydimethylsiloxanes, polythiazyls, polysilanes, polygermanes, more preferably a silica polymer.

5. The composite as claimed in any one of claims 1 to 4 characterized in that the powder comprises at least one metal selected from magnesium, tin, technetium, rhenium, titanium, iron, chromium, cobalt, gold, zinc, platinum, cadmium, aluminum, nickel, silver, beryllium, calcium and strontium.

6. The composite as claimed in any one of claims 1 to 5 characterized in that the powder comprises copper Cu.sup.0, oxidized and/or phosphorized, preferably in a proportion of 60% up to 100% by mass of the metal powder.

7. The composite as claimed in claim 6 characterized in that the oxidation ratio of the copper is greater than 95% by mass of oxidized copper relative to the total mass of copper in the powder.

8. The composite as claimed in any one of claims 1 to 7 characterized in that the metal powder comprises at least one non-metallic inorganic compound such as nitrogen, oxygen, phosphorus, sulfur, fluorine, chlorine, bromine, carbon, silicon.

9. The composite as claimed in any one of claims 1 to 8 characterized in that the composite comprises a proportion by mass of powder to binder comprised from 1:2 to 2:1 respectively, preferably from 1.2:1 to 1.6:1 respectively.

10. The composite as claimed in any one of claims 1 to 9 characterized in that said composite comprises a concentration gradient of powder grains, for example directed from the inside toward the outside of the composite and preferably increasing.

11. The composite as claimed in any one of claims 1 to 10 characterized in that said composite comprises a support or contains a reinforcement structure.

12. The composite as claimed in claim 11 characterized in that the reinforcement structure is a woven or nonwoven web.

13. The composite as claimed in any one of claims 1 to 12 for use as a film, preferably heat-shrinkable, or as a textile, preferably on a roll.

14. The composite as claimed in any one of claims 1 to 13 for use as a curtain, an adhesive film, a sleeve such as a door-handle sleeve, a tray, a garment or a part of a garment, a bag, a pouch, a tarpaulin, or as a tablecloth.

15. A method for fabricating a composite as claimed in any one of claims 1 to 14 characterized by the steps: (a) mix a precursor of the binder in the liquid state with the metal powder; (b) cast the mixture obtained in step (a) into a mold; (c) solidify the mixture of step (b), preferably by varying the temperature or by adding a catalyst; and (d) release the set composite from the mold.

16. The fabrication method as claimed in claim 15 characterized in that, before step (c), a support or a reinforcement structure is added to the composite or deposited in the mold.

17. A film, preferably heat-shrinkable, textile, preferably on a roll, curtain, sleeve such as a door-handle sleeve, garment or part of a garment, bag, pouch, tarpaulin, tray or tablecloth comprising a composite as claimed in any one of claims 1 to 15.

18. The film or textile as claimed in claim 17 characterized in that it has at least one additional adhesive layer.

19. Use of a film or a textile as claimed in claim 17 or 18 in a thermoforming process.

Description

DETAILED DESCRIPTION

[0089] A factor that should be taken into account in the context of the present invention is the particle size of the powder. Indeed, with regard to copper powder, the particle size of the copper powder according to the present invention will be the decisive factor in order to produce the flexible composite with the binding agent. Indeed, for certain powders, if the powder is too fine, the composite does not form correctly and has unacceptable physicochemical properties.

[0090] Thus, generally, there seems to be a threshold of around 30% by mass of grains of the powder, with respect to the total amount of powder, the diameter of which must be greater than 45 μm in order for the final coating/composite to be fabricated.

[0091] All the particle size values disclosed herein are applicable to other metals. However, it is not impossible that, for certain metals, this particle size is not a limiting factor and finer powders may be used successfully (by additional physicochemical effects: polarity, presence of fillers allowing incorporation, etc.).

[0092] Thus, the metal powder (preferably copper) can contain more than 40%, 50%, 75%, 90%, 95%, 100% by mass of grains the diameter of which is greater than 45 μm.

[0093] Furthermore, it seems important in certain embodiments of the present invention that at least a proportion, even very small, of the powder has a diameter less than 45 μm (e.g., in order to obtain continuity of the metal appearance in the composite). Thus, in a particular embodiment, the metal powder, preferably copper (Cu.sup.0, oxidized, phosphorized), does not contain more than 70%, 50%, 25%, 10%, 5%, 2% or 1% by mass of grains the diameter of which is less than 45 μm.

[0094] These particular embodiments, wherein the maximum amount of grains the diameter of which is less than 45 μm is defined, may be individually combined with ranges of minimum amounts of grains the diameter of which is less than 63 μm at most in the metal powder composition, preferably copper (Cu.sup.0, oxidized, phosphorized), according to the present invention. Thus, the metal powder contains at least 1%, 5%, 10%, 25%, 50%, 75%, 90% or 95% by mass of grains the diameter of which is less than 63 μm. In an embodiment of the present invention, the powder grains all are less than 500 μm in diameter. Advantageously, the powder grains all are less than 250 μm, 200 μm, 150 μm, 100 μm, 90 μm, 80 μm, 70 μm or 60 μm in diameter.

[0095] Thus, more particularly, the present invention relates to a metal powder composition, preferably copper (Cu.sup.0, oxidized, phosphorized), as defined above wherein the particle size distribution has the specific features detailed below.

[0096] According to a particular embodiment of the invention, the powder contains grains of the following diameters D: [0097] 1±1% by mass of grains of diameter D1: 125 μm≦D1 [0098] 2±2% by mass of grains of diameter D2: 106 μm≦D2<125 [0099] 12±10% by mass of grains of diameter D3: 75 μm≦D3<106 [0100] 10±5% by mass of grains of diameter D5: 63 μm≦D5<75 [0101] 20±10% by mass of grains of diameter D6: 45 μm≦D6<63 [0102] 40±30% by mass of grains of diameter D7: D7≦45

[0103] According to an advantageous embodiment of the invention, the powder contains grains of the following diameters D: [0104] 1±1% by mass of grains of diameter D1: 125 μm≦D1 [0105] 2±2% by mass of grains of diameter D2: 106 μm≦D2<125 [0106] 5±5% by mass of grains of diameter D3: 90 μm≦D3<106 [0107] 7±5% by mass of grains of diameter D4: 75 μm≦D4<90 [0108] 10±5% by mass of grains of diameter D5: 63 μm≦D5<75 [0109] 20±10% by mass of grains of diameter D6: 45 μm≦D6<63 [0110] 40±30% by mass of grains of diameter D7: D7≦45

[0111] According to an advantageous embodiment of the invention, the powder contains grains of the following diameters D: [0112] 1±0.5% by mass of grains of diameter D1: 125 μm≦D1 [0113] 2±1% by mass of grains of diameter D2: 106 μm≦D2<125 [0114] 5±2% by mass of grains of diameter D3: 90 μm≦D3<106 [0115] 7±2% by mass of grains of diameter D4: 75 μm≦D4<90 [0116] 10±3% by mass of grains of diameter D5: 63 μm≦D5<75 [0117] 20±5% by mass of grains of diameter D6: 45 μm≦D6<63 [0118] 50±20% by mass of grains of diameter D7: D7≦45

[0119] According to a more advantageous embodiment of the invention, the powder contains grains of the following diameters D: [0120] 0.9±0.1% by mass of grains of diameter D1: 125 μm≦D1 [0121] 1.5±0.5% by mass of grains of diameter D2: 106 μm≦D2<125 [0122] 4.5±1% by mass of grains of diameter D3: 90 μm≦D3<106 [0123] 6.5±1% by mass of grains of diameter D4: 75 μm≦D4<90 [0124] 8.5±1% by mass of grains of diameter D5: 63 μm≦D5<75 [0125] 18±5% by mass of grains of diameter D6: 45 μm≦D6<63 [0126] 60±10% by mass of grains of diameter D7: D7≦45

[0127] According to a more advantageous embodiment of the invention, the powder contains grains of the following diameters D: [0128] 0.9±0.1% by mass of grains of diameter D1: 125 μm≦D1 [0129] 1.5±0.5% by mass of grains of diameter D2: 106 μm≦D2<125 [0130] 4.5±1% by mass of grains of diameter D3: 90 μm≦D3<106 [0131] 6.5±1% by mass of grains of diameter D4: 75 μm≦D4<90 [0132] 8.5±1% by mass of grains of diameter D5: 63 μm≦D5<75 [0133] 18±5% by mass of grains of diameter D6: 45 μm≦D6<63 [0134] 60±5% by mass of grains of diameter D7: D7≦45

[0135] According to an embodiment even more advantageous of the invention, the powder contains grains of the following diameters D: [0136] 0.9% by mass of grains of diameter D1: 125 μm≦D1 [0137] 1.5% by mass of grains of diameter D2: 106 μm≦D2<125 [0138] 4.5% by mass of grains of diameter D3: 90 μm≦D3<106 [0139] 6.6% by mass of grains of diameter D4: 75 μm≦D4<90 [0140] 8.4% by mass of grains of diameter D5: 63 μm≦D5<75 [0141] 20.8% by mass of grains of diameter D6: 45 μm≦D6<63 [0142] 58.8% by mass of grains of diameter D7: D7≦45

[0143] According to an advantageous embodiment of the invention, the powder contains grains of the following diameters D: [0144] 1.0% by mass of grains of diameter D2: 106 μm≦D2 [0145] 8.1% by mass of grains of diameter D3′: 75 μm≦D3′<106 [0146] 7.9% by mass of grains of diameter D5: 63 μm≦D5<75 [0147] 19.2% by mass of grains of diameter D6: 45 μm≦D6<63 [0148] 63.8% by mass of grains of diameter D7: D7≦45

[0149] Traditionally, the mass percentages are added to have a cumulative particle size according to the standard ISO 4497. It is easy for the skilled person, in view of the ranges given above, simply to add the values in order to find the current particle size standards (cumulative).

[0150] As said before, these particle size values are independent of the chemical nature of the powder, and simply enable the powders to be incorporated into a binder. However, variations of particular technical effects (biocidal activity, pigmentation) can be obtained according to the fineness of the powder.

[0151] More particularly, the present invention relates to a composite as described above characterized in that the Young's modulus (E) is less than 3 GPa, less than 2 GPa, particularly less than 1 GPa, preferably less than 0.5 GPa, 0.4 GPa, 0.3 GPa, or 0.2 GPa. Advantageously, the composite as described above is characterized in that the Young's modulus (E) is less than 2 GPa, particularly 1 GPa, 0.9 GPa, 0.8 GPa, 0.7 GP.

[0152] Advantageously, the composite as described above is characterized in that the Young's modulus (E) is less than 0.1 GPa, 0.09 GPa, 0.08 GPa, 0.07 GPa, 0.06 GPa 0.05 GPa, 0.04 GPa, 0.03 GPa, 0.02 GPa, 0.01 GPa.

[0153] More advantageously, the composite as described above is characterized in that the Young's modulus (E) is between 0.001 and 5 GPa, 0.005 and 4 GPa, 0.01 and 3 GPa, 0.05 and 2 GPa, 0.1 and 1 GPa, 0.2 and 0.7 GPa or between 0.3 and 0.5 GPa.

[0154] More advantageously, the composite as described above is characterized in that the Young's modulus (E) is equivalent to that of rubber, i.e., between 0.001 and 0.1 GPa, equivalent to that of polyethylene, i.e., between 0.2 and 0.7 GPa, equivalent to that of polystyrene, i.e., between 3 and 3.4 GPa, equivalent to that of Nylon®, i.e., between 2 and 5 GPa, in particular between 2.5 and 4 GPa.

[0155] The Young's modulus of the composite according to the invention is evaluated at room temperature, or about 20° C., and the values indicated above correspond to that temperature.

[0156] Thus, the composite according to the present invention is characterized in that the binder is an organic or inorganic binder, or a mixture of both.

[0157] Advantageously, the composite according to the present invention is characterized in that the binder is selected from a plastic, a latex, a rubber, a polyethylene, polypropylene, polyurethane, an epoxy polymer, vinyl ester, aqueous-phase polymers, Nylons®, polyamides, polycarbonates, polystyrenes, polymethylmethacrylate, a silica polymer such as a silicone, polydimethylsiloxanes, polythiazyls, polysilanes, polygermanes, more preferably a silica polymer. Advantageously, it is an elastomer binder as defined above, in particular with elasticity values as described above. Indeed, in the embodiments of the present invention, the elasticity of the initial polymer (without powder) is altered only very little by the addition of metal powder, in particular in the proportions (powder/binder) described below.

[0158] More advantageously, the composite according to the present invention is characterized in that the binder is selected from a plastic, a latex, a rubber, a polyethylene, polyurethane, an epoxy polymer, aqueous-phase polymers, Nylons®, polyamides, a silica polymer such as a silicone, polydimethylsiloxanes, polythiazyls, polysilanes, polygermanes.

[0159] Even more advantageously, the composite according to the present invention is characterized in that the binder is selected from a latex, a rubber, a polyethylene, polyurethane, Nylons®, polyamides, a silica polymer such as a silicone, polydimethylsiloxanes, polythiazyls, polysilanes, polygermanes

[0160] More advantageously, the composite according to the present invention is characterized in that the powder comprises at least one metal selected from magnesium, tin, technetium, rhenium, titanium, iron, chromium, cobalt, gold, zinc, platinum, cadmium, aluminum, nickel, silver, beryllium, calcium and strontium.

[0161] Even more advantageously, the composite according to the present invention is characterized in that the powder comprises copper Cu.sup.0, oxidized or phosphorized, preferably in a proportion of 60% up to 100% by mass of the metal powder.

[0162] More particularly, the object of the present invention relates to a composition of copper Cu.sup.0 powder, oxidized and/or phosphorized as defined above wherein the copper mass is greater than or equal to 65%, advantageously greater than 70%, more advantageously greater than 75%, even more advantageously greater than 80%, even more advantageously greater than 85%, even more advantageously greater than 90%, even more advantageously greater than 95%, even more advantageously greater than 97%, even more advantageously greater than 98%, even more advantageously greater than 99%, even more advantageously greater than 99.5%, even more advantageously greater than 99.9% by mass relative to the total mass of the powder composition.

[0163] With regard to the density of the powders used, it is generally between 1 and 5 g/cm.sup.3, more particularly between 1.5 and 3 g/cm.sup.3, 1.5 and 2 g/cm.sup.3, 2 and 3 g/cm.sup.3, 2 and 2.5 g/cm.sup.3, 2.5 and 3 g/cm.sup.3. The density will depend on both the particle size and the chemical nature of the powder, for example of its degree of oxidation.

[0164] Advantageously, the composite according to the present invention is characterized in that the oxidation ratio of the copper is greater than 95% by mass of oxidized copper relative to the total mass of copper in the powder.

[0165] Preferably, the oxidized copper composition according to the present invention is characterized in that the copper grains are oxidized to the core.

[0166] The oxidized copper composition according to the present invention is characterized in that copper is oxidized in various proportions: for example, the oxidized copper composition may be oxidized in a proportion of 5%, 10%, 15%, 20%, 25%, 30%, 35%, 40%, 45%, 50%, 55%, 60%, 65%, 70%, 75%, 80%, 85%, 90% or 95% by mass of oxidized copper relative to the total mass of copper.

[0167] This degree of oxidation makes it possible to adjust the biocidal activity of the composite of the present invention.

[0168] According to an embodiment of the present invention, the oxidized copper composition incorporated into the composite according to the present invention is characterized in that the oxidation ratio of the copper is greater than 95% by mass of oxidized copper relative to the total mass of copper and/or in that the amount of phosphorus is between 2% and 16%, preferably 8% by mass relative to the total mass of powder.

[0169] For example, according to an embodiment of the present invention, the oxidized copper composition incorporated into the composite according to the present invention is characterized in that the oxidation ratio of the copper is 95.5%, 96%, 96.5%, 97%, 97.5%, 98%, 98.5%, 99%, 99.5%, 99.7%, 99.8%, 99.9% or 100% by mass of oxidized copper relative to the total mass of copper.

[0170] Furthermore, techniques for determining copper content are extremely common in the art and may be carried out by chemical and/or physical means.

[0171] Advantageously, the composite according to the present invention is characterized in that the metal powder comprises at least one non-metallic inorganic compound such as nitrogen, oxygen, phosphorus, sulfur, fluorine, chlorine, bromine, carbon, silicon.

[0172] Advantageously, the composite according to the present invention is characterized in that the composite comprises a proportion by mass of powder to binder of 1:2 to 2:1 respectively, preferably of 1.2:1 to 1.6:1 respectively. For example, the composite of metal powder and binding agent as defined above is characterized in that the proportion by mass of powder to binder in the composition is from 1.1:1 to 1.8:1 respectively, from 1.15:1 to 1.6:1 respectively, from 1.2:1 to 1.4:1 respectively, from 1.25:1 to 1.3:1 respectively, or is 1.275:1 respectively.

[0173] Advantageously, the composite according to the present invention is characterized in that said composite comprises a concentration gradient of powder grains, for example directed from the inside toward the outside of the composite and preferably increasing.

[0174] Advantageously, the composite according to the present invention is characterized in that said composite comprises a support or contains a reinforcement structure.

[0175] Advantageously, the composite as above is characterized in that the reinforcement structure is a woven or nonwoven web.

[0176] Advantageously, a fabric used as woven or nonwoven web may be a natural fabric, such as cotton, or a synthetic fabric, such as Nylon®.

[0177] Advantageously, the present invention relates to the composite according to the present invention for use as a film, preferably heat-shrinkable, or as a textile, preferably on a roll.

[0178] Advantageously, the present invention relates to the composite according to the present invention for use as a substrate, in particular thread or filament, for 3D printing.

[0179] By 3D printing is meant additive manufacturing methods. These methods were developed for rapid prototyping and, by way of example, mention may be made of a few coexisting technologies: fused deposition modeling (FDM) or stereolithography (SLA: UV light solidifies a layer of liquid plastic). Thus, the composite according to the invention may be used to fabricate articles by 3D printing via FDM or SLA technology. In particular, FDM consists in melting a filament of synthetic material such as a composite according to the invention through a nozzle (an extruder) heated to a temperature varying between 160° C. and 400° C. (in the context of polymer fusion). A thin plastic thread in the melting state exits therefrom and it is deposited in a line and comes to adhere by re-melting to the material deposited previously. Thus, reels of composite according to the invention can be used with 3D printing technology, in particular fused deposition modeling. In the present case, the composition binder is a thermoplastic binder.

[0180] The composite according to the invention may also be used with SLA technology wherein the binder is a polymer that can be hardened by a UV-activatable curing catalyst.

[0181] Advantageously, the present invention relates to the composite as defined herein for use as a curtain, an adhesive film, a sleeve, such as a door-handle sleeve, a tray, a garment or a part of a garment, a bag, a pouch, a tarpaulin, or as a tablecloth. These various objects can be used in the technical fields requiring in particular a sterile or microorganism-depleted environment, such as agri-food, pharmaceutical or healthcare environments.

[0182] The present invention also relates to the composite as defined in the present description for the fabrication of granules, plates and ingredients for plastics technology.

[0183] The composite granules and plates according to the invention may be advantageously used for the fabrication of parts and articles formed by known plastics technology techniques.

[0184] With regard to the techniques for forming the composite according to the invention, mention may be made of:

[0185] Contact molding: Manual method for producing parts from thermosetting resins, at room temperature and without pressure. The reinforcements may be deposited on the mold and impregnated with liquid resin, accelerated and catalyzed, to be gradually formed by means of bubble-removing rollers and brushes. After the resin hardens, the part is unmolded and trimmed.

[0186] Molding by simultaneous spraying: Manual or automated method for fabricating parts from thermosetting resins at room temperature and without pressure. The raw materials are applied using a so-called “spraying” machine comprising a cutting device, a spraying of the optional reinforcement (roving) and one or two spray guns spraying the resin simultaneously. The cut threads and the resin are sprayed onto the mold surface and then compacted and bubbles are removed using rollers. The pre-accelerated resin is catalyzed continuously as it is sprayed.

[0187] Vacuum molding: carried out between mold and rigid, semi-rigid or flexible counter-mold according to the characteristics of the parts.

[0188] A reinforcement (mat, fabric, preform) may be placed inside the mold; the catalyzed resin is cast into the mold. One uses the pressure exerted on the mold during the vacuum process to distribute the resin and to impregnate the optionally-present reinforcement. The resin may also be admitted intermittently by aspiration consecutive to the vacuum.

[0189] Injection molding: Resin transfer molding (RTM) is carried out between rigid mold and counter-mold. A reinforcement (mats, preform, possibly fabrics) may be disposed in the gap between the molds. Once the latter are firmly closed, the resin, accelerated and catalyzed, is injected under low pressure (1.5 to 4 bar) through the reinforcement until the impression is completely filled. After the resin cures, the mold is opened and the part unmolded.

[0190] Low-pressure “wet” cold-press molding: using a compression press between rigid mold and rigid counter-mold, initially with no external heat supply.

[0191] With the mold open, the reinforcement can be positioned on the lower part of the mold and the resin, equipped with a highly-reactive catalytic system, is poured in bulk onto the reinforcement.

[0192] Closing the mold under pressure (2 to 4 bar) leads to distribution of the resin in the impression and impregnation of the reinforcement. The hardening of the resin is gradually accelerated by the increased temperature of the mold due to the exothermic nature of the reaction, which allows rapid unmolding.

[0193] Bulk Molding Compound (BMC)

[0194] Bulk molding compound prepared in a mixer is a moldable mass consisting of resin, various fillers and adjuvants, reinforced with cut glass fiber as need be.

[0195] The composite is heat molded (130-150° C.) by injection (chiefly) between mold and counter-mold of machined steel. The closing pressure (50 to 100 bar) of the mold leads to creep of the pre-measured material and filling of the impression. The very short curing time enables rapid unmolding.

[0196] Centrifugal Molding

[0197] Inside a mold rotating at low speed are deposited particles of the catalyzed and accelerated resin and optionally granular fillers. The rotational speed of the mold is then increased to remove bubbles from the material and to make the material denser. After the resin is cured, optionally accelerated by a heat supply, the part can be extracted from the mold very easily. This technology also applies to thermoplastic resins where the mixture is heated to fluidify it, which allows, as the mold rotates, distribution into the shapes of said mold. The mixture is cooled and solidified and the part is unmolded.

[0198] Advantageously, the composite film or textile according to the present invention is characterized in that it has at least one additional adhesive layer. The addition of an adhesive on the composite of the present invention may be carried out by any technique known in the art, such as the spraying of an adhesive agent, or by soaking, impregnation, etc.

[0199] The present invention also relates to a fabrication method as described above.

[0200] The fabrication of a metal powder as defined above is carried out by techniques common in the field. Generally, fractionation of the metal into powder can be carried out by any technique known in the art, whether by mechanical, chemical or physical fractionation, etc. It is possible to obtain the desired powder according to the present invention directly by adequate fractionation, which involves perfect control of the technique by the operator who, nevertheless, calls upon general knowledge of the art. Moreover, an easier alternative technique is well-known in the art, which consists in fractionating the material coarsely with relatively irregular particle size, followed by successive sieving operations, in order to isolate particular powder populations (i.e., of particular and regular particle size). In the context of the present invention, this technique is quite applicable: A rough fractionation can be carried out, followed by a step of sampling and isolating the particular powders, then a step of selecting the powder in order to reconstitute the powder according to the invention. These techniques are extremely common in the art. Indeed, the control of particle size forms part of the general knowledge of the skilled person. Thus, it is obvious in the context of the present invention that it is possible to add other compounds/powders in order to obtain a “mixed” composition, having the technical effects disclosed herein in addition to other effects provided by the secondary compounds/powders added. Advantageously, the powders with given particle size were obtained by any one of the fractionation techniques known in the art, followed by passing at least twice over molecular sieves to ensure that the size of the particles constituting the powder are neither too small nor too large in given amounts, thus ensuring perfect control of the essential features needed to carry out the present invention. Nevertheless, and preferably, fractionation is carried out by an atomization technique, for example with water (following metallic melt). A suitable powder can be obtained from the company POUDMET (France), for example.

[0201] Thus, the method for fabricating a composition according to the present invention is characterized in that the metal powder, preferably copper (Cu.sup.0, oxidized and/or phosphorized), is obtained directly by fractionation or is reconstituted from several powders with given particle sizes and proportions of metals (e.g., copper).

[0202] Advantageously, the particles obtained by such techniques are between 8 and 150 μm (D50) and/or the amount of oxygen comprised in the composition is between 0.3% and 5% by weight.

[0203] Nevertheless, according to an embodiment of the invention the oxidation of the copper itself may occur after fractionation by passing the composition in the oven under controlled atmosphere.

[0204] With regard to oxidized copper powder, for example, oxidation may occur at a temperature equal to or greater than 500° C. in the presence of oxygen and/or an oxygen source, preferably in the presence of magnesium or phosphorus. According to an embodiment, the temperature is greater than 800° C., 1000° C., 1500° C. or 2000° C.

[0205] Oxygen or an oxygen-containing gas may be blown directly into the copper. Generally, this is done in open air. A compound of the powder itself which, when heated, releases oxygen may also be incorporated. Of course, the copper may be fractionated before being heated in order to enable better oxidation. The copper may nevertheless be oxidized before being fractionated into powder.

[0206] Advantageously, the fabrication method according to the present invention is characterized in that, before step (c), a support or a reinforcement structure is added to the composite or deposited in the mold.

[0207] Furthermore, the composite (solid) according to the present invention may be fabricated by any technique known in the field applicable to the fabrication of flexible compounds such as rubber. Thus, extrusion, thermoforming and coating techniques, etc., are quite applicable to the present specific case.

FIGURE

[0208] FIG. 1: Photograph of the fabric obtained according to Example 3.

EXAMPLES

[0209] In order to illustrate the present invention, the following examples were prepared. In no case is the object of the present invention limited to these examples alone.

[0210] 1. CuP.sub.8-Based Powders

[0211] CuP.sub.8 powder, the particle size of which is not controlled, is known to be used in brazing.

[0212] Conventionally, it has the following characteristics: [0213] Nominal composition (% mass): Cu: 92 [0214] P: 8 [0215] Melting point: 710-750° C. [0216] Density: 8 g/cm.sup.3 [0217] Protocol for fabricating the copper-phosphorus powder according to the invention

[0218] According to the present invention, the copper-phosphorus alloy containing a percentage of phosphorus between 2% and 16%, preferably 8%, is introduced into the melt bath. This alloy is then atomized with water under conditions such that the particle size results must be between 8 and 150 μm (D50); the oxygen content is between 0.3% and 5% by weight. [0219] The following powder was thus obtained:

TABLE-US-00001 TABLE 1 Particle size, cumulative % retained (ISO 4497) Percentages Cumulative percentages Particle size by interval retained ≧125 μm  0.0 0.0 ≧106 μm  0.9 0.9 ≧90 μm 4.5 5.4 ≧75 μm 6.6 12.0 ≧63 μm 8.4 20.4 ≧45 μm 20.8 41.2 <45 μm 58.8 58.8 Total 100% 100% (41.2 + 58.8) Density obtained: 2.67 g/cm.sup.3 (ISO 3923/2) P % obtained: 8.0% by mass

[0220] 2. Oxidized copper powder

[0221] The same protocol as for copper-phosphate was applied for copper.

The following powder was thus obtained:

TABLE-US-00002 TABLE 2 Particle size, cumulative % retained (ISO 4497) Percentages Cumulative percentages Particle size by interval retained ≧125 μm  0.0 0.0 ≧106 μm  1.0 1.0 ≧75 μm 8.1 9.1 ≧63 μm 7.9 17.0 ≧45 μm 19.2 36.2 <45 μm 63.8 63.8 Total 100% 100% (36.2 + 63.8) Density obtained: 2.88 g/cm.sup.3 O.sub.T %: 0.35% by mass (ISO 4491-4)

[0222] Next, the powder obtained passed into a conveyor oven at a temperature above 500° C. (about 800° C. in the present case) in order to oxidize it, under controlled atmosphere.

[0223] A powder with the same particle size as before was obtained with: [0224] density: 1.60 g/cm.sup.3 [0225] O.sub.T %: 0.08% by mass [0226] Cu %>99.7% by mass

[0227] 3. Example of the Composite Obtained

[0228] The composites are obtained simply by mixing the compounds together.

[0229] It is strongly advised to respect the curing times of the composite (about 20 min at 20° C. per layer; impregnation to be carried out within this time if a woven/nonwoven web is present). The binder may be heated beforehand to fluidify it, which reduces the curing time.

TABLE-US-00003 TABLE 3 Composite(s) obtained Composite Metal powder CuP.sub.8 (powder of Example 1) Binder ISOCYANATE 74% (proportions by mass) Curing agent POLYOL 26% (proportions by mass) Proportions by Powder = 1 mass of powder Binder = 1 to binder Suspension yes possible Curing time 20 minutes

[0230] For example, the composite of Table 3 was impregnated simply by soaking into a woven web (commercial fabric comprising synthetic and natural fibers) before the effective curing time (see FIG. 1: photograph of the material obtained). The fabric obtained kept its initial mechanical properties (flexibility) while having the additional physicochemical properties provided by the composite of Table 3.

[0231] 4. Biocidal Activity

[0232] Copper powders (Cu.sup.0, oxidized and/or phosphorized) have been studied previously in rigid coatings and demonstrated proven biocidal activity. The composite according to the present invention thus also has the same biocidal activity.