EP0528192B1 - Metal-coated melamine-formaldehyde fibers - Google Patents

Metal-coated melamine-formaldehyde fibers Download PDF

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Publication number
EP0528192B1
EP0528192B1 EP92112480A EP92112480A EP0528192B1 EP 0528192 B1 EP0528192 B1 EP 0528192B1 EP 92112480 A EP92112480 A EP 92112480A EP 92112480 A EP92112480 A EP 92112480A EP 0528192 B1 EP0528192 B1 EP 0528192B1
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EP
European Patent Office
Prior art keywords
fibers
metal
water
melamine
metal salt
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EP92112480A
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German (de)
French (fr)
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EP0528192A1 (en
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Joerg Dr. Adel
Bernd Dr. Ziegler
Erwin Dr. Hahn
Georg Mermigidis
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BASF SE
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BASF SE
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    • D—TEXTILES; PAPER
    • D06—TREATMENT OF TEXTILES OR THE LIKE; LAUNDERING; FLEXIBLE MATERIALS NOT OTHERWISE PROVIDED FOR
    • D06M—TREATMENT, NOT PROVIDED FOR ELSEWHERE IN CLASS D06, OF FIBRES, THREADS, YARNS, FABRICS, FEATHERS OR FIBROUS GOODS MADE FROM SUCH MATERIALS
    • D06M11/00—Treating fibres, threads, yarns, fabrics or fibrous goods made from such materials, with inorganic substances or complexes thereof; Such treatment combined with mechanical treatment, e.g. mercerising
    • D06M11/83—Treating fibres, threads, yarns, fabrics or fibrous goods made from such materials, with inorganic substances or complexes thereof; Such treatment combined with mechanical treatment, e.g. mercerising with metals; with metal-generating compounds, e.g. metal carbonyls; Reduction of metal compounds on textiles
    • D—TEXTILES; PAPER
    • D06—TREATMENT OF TEXTILES OR THE LIKE; LAUNDERING; FLEXIBLE MATERIALS NOT OTHERWISE PROVIDED FOR
    • D06Q—DECORATING TEXTILES
    • D06Q1/00—Decorating textiles
    • D06Q1/04—Decorating textiles by metallising

Definitions

  • the present invention relates to metal-coated melamine-formaldehyde resin fibers.
  • the present invention relates to a process for the production of these fibers, the use for the production of composite materials and composite materials which contain these fibers.
  • Electromagnetic waves can have a negative impact on the transmission of messages and electronic data processing, for example. We are therefore looking for materials that are able to reflect disturbing electromagnetic waves.
  • the shielding of electromagnetic radiation in the frequency range from 10 kHz to 10 GHz is of increasing importance e.g. in the future development of plastic computer housings.
  • plastics with shielding they can be mixed with conductive fillers such as graphite (soot), metal powder, platelets and fibers as well as metallized glass or carbon fibers.
  • DE-B-27 43 768 discloses polyacrylonitrile and cotton fiber fibers metallized with nickel or copper.
  • DE-A-38 10 597 describes composite materials which contain metallized fibers. Glass fibers, aramid fibers and carbon fibers are used as fibers, which can be metallized in a conventional manner, for example by electroless or galvanic metallization, by sputtering or vapor deposition. According to DE-A 38 10 597, the metallized fibers are provided with a polymer protective layer.
  • US-A-4,803,097 describes a method for applying a metal layer to natural or artificial materials, the material to be coated (a) first being exposed to an ozone atmosphere, then (b) conditioned with a solvent in a basic medium, then (c) with a Oxidizing agent contacted, (d) then provided with a metal layer, and (e) finally heated. Before applying the metal layer, the material to be coated must be activated with noble metal seeds.
  • the object of the present invention was therefore to produce metallized fibers which do not have the disadvantages mentioned.
  • fibers produced by the process according to the invention the use of these fibers for the production of composite materials and composite materials containing these fibers were found.
  • Fibers made from melamine-formaldehyde condensates and their production are known, for example, from DE-B-23 64 091, EP-B 93965 and "Chemical fibers / textile industry", 40./92. Vintage, 12/90, T154, known.
  • these fibers contain at least 80% by weight of a melamine-formaldehyde precondensate, which is composed of melamine and formaldehyde in a molar ratio of melamine to formaldehyde of 1: 1.5 to 1: 4.5, and additionally up to 20% by weight .-% other amino, amide, hydroxyl or carboxyl group-containing thermoset on the one hand and aldehydes on the other.
  • the fibers can then be produced therefrom by customary methods, as described, for example, in the literature cited above.
  • Melamine-formaldehyde resin fibers with a diameter of 5 to 100 ⁇ m, preferably 8 to 20 ⁇ m, are generally used. Both continuous fibers (rovings) and fiber chips with a length of 1 to 200, preferably 1 to 50 mm, can be used for the coating.
  • sheet-like structures such as woven, knitted or non-woven fabrics made from the fibers.
  • transition metals can be used as metals for coating the fibers.
  • examples include: chromium, molybdenum, tungsten, manganese, iron, cobalt, nickel, palladium, platinum, copper, silver and gold, preferably molybdenum, cobalt, nickel, palladium, platinum, copper, silver and gold, particularly preferably nickel, copper , Molybdenum, palladium, silver, platinum and gold.
  • the thickness of the metal coating is generally chosen from 0.01 to 1, preferably from 0.2 to 0.5 ⁇ m.
  • the weight ratio of fiber to metal is generally chosen between 100: 1 to 0.5: 1, preferably from 4: 1 to 1: 1.
  • the metal coating in aqueous solution is generally carried out by first providing the surface of the fibers with metal nuclei (“activated”) and then depositing the desired metal on this layer.
  • the coating can also be carried out by decomposing transition metal carbonyl compounds in a manner known per se, such as thermolysis (chemical vapor deposition) or photolysis in the presence of the melamine resin fibers.
  • the activation or first coating of the melamine fibers can be achieved in a manner known per se by treating the fibers with an aqueous solution containing a water-soluble metal salt, with the exception of the noble metal salt and another, less noble metal salt as reducing agent (see, for example, WO-A-89 / 06710).
  • suitable metal salts are the water-soluble salts of copper, such as copper (I) chloride and copper (II) sulfate.
  • Tin (II) chloride or titanium (III) chloride is preferably used as the reducing agent.
  • the metal salt is preferably used in the form of its aqueous solution in concentrations of 0.1 to 5, preferably 0.2 to 0.5 g / l.
  • the molar ratio of reducing agent to metal salt is generally 1: 1 to 4: 1, preferably from 1: 1 to 2: 1.
  • the fibers are generally used in amounts of 0.1 to 10, preferably 0.5 to 1% by weight (based on the amount of water).
  • the reaction is generally carried out at room temperature and under atmospheric pressure, but it is also possible, for example, to choose higher temperatures and pressures, preferably up to 95 ° C. and up to 500 kPa.
  • the pH range at the beginning of the activation is generally not critical and essentially depends only on the substances used and their respective amounts.
  • Melamine resin fibers can also be activated by treating them with an aqueous solution containing a water-soluble metal salt, with the exception of the noble metal salt, a complexing agent and a hydride compound as reducing agent.
  • an aqueous solution consisting of the metal salt and the complexing agent is first prepared. After a constant pH has been established, the fibers are added, and the reducing agent is then added, advantageously in portions, until the metal precipitates at the point of dropping. The solution is then stirred or shaken until no further brightening of the solution is observed. As a rule, the fibers become discolored. In general, the process of adding the reducing agent is repeated until no further deepening of the color of the fibers is discernible. As much of the reducing agent is preferably added until the pH of the solution is increased by 1 to 2 units, preferably 1.25 to 1.75 units.
  • metal salts examples include: cobalt (II) chloride, nickel (II) chloride, copper (II) sulfate, preferably nickel (II) chloride, Copper (II) sulfate, particularly preferably copper (II) sulfate.
  • Organic complexing agents such as carboxylic acids or carboxylic acid derivatives, for example citric acid, trisodium citrate, sodium acetate, salicylic acid, potassium sodium tartrate, succinic acid, glycine, L-aspartic acid, L-glutamic acid, alcohols or alcohol derivatives, for example glycerol, can generally be used as complexing agents , 1,3-propanediol, ethylene glycol, 3-amino-1-propanol, mannitol, and also acetylacetone, 2-propanethiol, ethyl acetoacetate, ethylenediaminetetraacetate (“EDTA”), biuret or crown ethers such as 15-crown-5 and 18-crown-6 , preferably citric acid, trisodium citrate, glycine, particularly preferably citric acid.
  • citric acid trisodium citrate
  • sodium acetate salicylic acid, potassium sodium tartrate
  • succinic acid
  • the hydride compound used for the activation is generally sodium borohydride or the borane-dimethylamine complex, preferably sodium borohydride.
  • the metal salt can be used in a concentration range from 0.01 to 1, preferably from 0.05 to 0.2 g / l.
  • the fibers are generally used in amounts of 0.1 to 10, preferably 0.5 to 1% by weight (based on the amount of water).
  • the amount of the complexing agent is generally from 100 to 400, preferably from 100 to 200 mol% (based on the metal salt).
  • the amount of reducing agent is generally chosen in a range from 100 to 400, preferably from 100 to 200 mol% (based on the metal salt).
  • the reaction is usually carried out in a temperature range from 10 to 50, preferably from 15 to 35 ° C. under atmospheric pressure.
  • the pH at the start of the reaction is essentially dependent on the metal salt selected and is generally less than pH 7.
  • the duration of the activation is not critical. They are usually selected in the range from 30 to 300, preferably from 50 to 120, minutes.
  • a layer of Cu (I) oxide usually forms on the fiber surface, which is usually further reduced to metallic copper with a basic, aqueous reducing solution.
  • a hydride compound is preferably used as the reducing agent. When reducing to metal, the fibers usually become discolored. In general, the process of adding the reducing solution is repeated until no further deepening of the color of the fibers is discernible.
  • the hydride compound used in the reduction of Cu (I) oxide is generally sodium borohydride or the borane-dimethylamine complex, preferably sodium borohydride.
  • An alkali metal or alkaline earth metal hydroxide or oxide such as lithium hydroxide, sodium hydroxide, potassium hydroxide, sodium oxide, magnesium hydroxide or calcium hydroxide, preferably sodium hydroxide and potassium hydroxide, is generally used as the base in the solution for the reduction of Cu (I) oxide.
  • the amount of the hydride compound in the solution for reducing Cu (I) oxide is usually selected in the range from 1 to 5 g / l of water.
  • the amount of base is usually chosen in the range from 0.1 to 1 g / l water.
  • the reduction of the Cu (I) oxide is generally carried out in a temperature range from 10 to 50, preferably from 15 to 35 ° C. under atmospheric pressure.
  • the pH of the solution for reducing the Cu (I) oxide is generally selected in the range from 7 to 14, preferably from 10 to 12.
  • the duration of the Cu (I) oxide reduction is selected in the range from 30 to 300, preferably from 60 to 120, minutes.
  • the actual coating of the melamine resin fibers is generally carried out by treating the melamine resin fibers pretreated by the methods described above with an aqueous solution containing a water-soluble metal salt, a complexing agent and a reducing agent.
  • a solution is first prepared from the water-soluble metal salt in water and then the complexing agent is added. Subsequently, the pH which is favorable for the reduction is generally set and the reducing agent is then added, preferably as an aqueous one Solution, too.
  • the melamine resin fibers can then be added, and the fibers can be added batchwise or continuously.
  • all water-soluble transition metal salts can be used as the metal salt.
  • examples include: cobalt (II) chloride, nickel (II) chloride, palladium (II) chloride, platinum (II) chloride, copper (II) sulfate, silver nitrate and gold (III ) chloride, preferably nickel (II) chloride, palladium (II) chloride, platinum (II) chloride, copper (II) sulfate, silver nitrate and gold (III) chloride, particularly preferably palladium - (II) chloride, copper (II) sulfate, silver nitrate and gold (III) chloride.
  • Tartrates such as potassium sodium tartrate, dipotassium tartrate, disodium tartrate, potassium tartrate, sodium tartrate or diammonium tartrate, trisodium citrate and EDTA are generally used as complexing agents.
  • the reducing agent used is generally formaldehyde, advantageously in the form of an aqueous solution, sodium borohydride, borane-dimethylamine complex, sodium hypophosphite (NaH 2 PO 2 .H 2 O) or hydrazine.
  • Sodium borohydride is preferably used to reduce copper and nickel, formaldehyde to reduce copper and silver, Borane-dimethylamine complex and sodium hypophosphite for the reduction of nickel.
  • pH range essentially depends on the choice of reducing agent.
  • a pH range from 10 to 14 is chosen for the reduction with formaldehyde, the solution generally being made basic with alkali metal hydroxides or oxides, for example sodium or potassium hydroxide.
  • a pH range from 5 to 10 is preferably selected for the reduction with hypophosphite and with borane-dimethylamine complex.
  • the pH is generally adjusted using buffer systems which are customary in these areas, for example NH 3 / NH 4 Cl or Acetic acid / sodium acetate.
  • the reduction with sodium borohydride is usually carried out in a pH range from 7 to 14, the reduction solution generally being made basic with alkali metal hydroxides or oxides, for example sodium or potassium hydroxide.
  • the metal salt can be used in a concentration range from 5 to 200, preferably from 10 to 50 g / l.
  • the fibers are generally used in amounts of 0.1 to 10% by weight, preferably 0.3 to 1% by weight (based on the amount of water).
  • the amount of the complexing agent is usually 100 to 400, preferably 100 to 200 mol% (based on the metal salt).
  • the amount of reducing agent is generally chosen in a range from 100 to 400, preferably from 100 to 200 mol% (based on the metal salt).
  • the metallization can be carried out in a temperature range from 15 to 95, preferably from 15 to 35 ° C. and under atmospheric pressure.
  • a temperature range from 60 to 95 ° C. is preferred for the metallization with nickel, and a temperature range from 50 to 80 ° C. for the metallization with silver.
  • the duration of the metallization essentially depends on the desired layer thickness and on the selected concentrations of the starting materials. They are generally chosen in the range from 30 to 300, preferably from 60 to 120, minutes.
  • the metal-coated melamine resin fibers according to the invention can be processed in a conventional manner together with other polymeric molding compositions such as thermoplastics and thermosets to form composite materials.
  • thermoplastic For the production of composite materials with thermoplastics one works according to known methods.
  • the thermoplastic can be melted in a heatable mixing unit and the metallized melamine resin fibers according to the invention can be incorporated into the melt as continuous fibers (rovings) or as fiber chips (chopped strand).
  • the melt can then be extruded, injection molded or pressed as a strand.
  • thermosets The production of composite materials with thermosets is generally also carried out by customary methods, for example by impregnating the melamine resin fibers according to the invention with the liquid starting materials and then curing them.
  • thermoplastics and thermosets and their mixtures can be used as the polymer matrix.
  • examples include polyamides, polyvinyl chloride, polyolefins, polyesters, aromatic polyethers, unsaturated polyester resins and polyurethanes.
  • the proportion of the melamine resin fibers according to the invention is generally selected in the range from 1 to 40, preferably from 5 to 25,% by weight, based on the weight of the composite material.
  • the composite materials according to the invention can also contain the usual additives and processing aids such as stabilizers, flame retardants, impact modifiers, antioxidants, lubricants, fillers and dyes and pigments as well as carbon black and / or graphite.
  • additives and processing aids such as stabilizers, flame retardants, impact modifiers, antioxidants, lubricants, fillers and dyes and pigments as well as carbon black and / or graphite.
  • the melamine resin fibers according to the invention are distinguished from known metallized fibers or metal fibers by their low specific weight, their high flexibility, their cost-effective production, their excellent flame retardant properties and their very good thermal resistance.
  • the metal content determination of the fibers in the following experiments was carried out by means of atomic absorption spectroscopy.
  • the conductivity was determined using a four-point method on single fibers. For this purpose, a current of 100 mA was passed through the fiber by means of two platinum electrodes (pair A) which were at a distance of approximately 1 cm from one another and were connected to the fiber surface. Two further electrodes (pair B) were then placed at a distance of 0.33 cm from one another in the area between the two electrodes. The voltage U was measured by means of the pair of electrodes B.

Description

Die vorliegende Erfindung betrifft metallbeschichtete Melamin-Formaldehyd-Harz-Fasern.The present invention relates to metal-coated melamine-formaldehyde resin fibers.

Außerdem betrifft die vorliegende Erfindung ein Verfahren zur Herstellung dieser Fasern, die Verwendung zur Herstellung von Verbundwerkstoffen sowie Verbundwerkstoffe, die diese Fasern enthalten.In addition, the present invention relates to a process for the production of these fibers, the use for the production of composite materials and composite materials which contain these fibers.

Elektromagnetische Wellen können als Störstrahlung beispielsweise die Nachrichtenübermittlung und die elektronische Datenverarbeitung negativ beeinflussen. Es wird daher nach Materialien gesucht, die in der Lage sind störende elektromagnetischen Wellen zu reflektieren.Electromagnetic waves can have a negative impact on the transmission of messages and electronic data processing, for example. We are therefore looking for materials that are able to reflect disturbing electromagnetic waves.

So hat die Abschirmung von elektromagnetischer Strahlung im Frequenzbereich von 10 kHz bis 10 GHz steigende Bedeutung z.B. bei der zukünftigen Entwicklung von Computergehäusen aus Kunststoff. Um Kunststoffe abschirmend auszurüsten, kann man sie mit leitfähigen Füllstoffen wie Graphit (Ruß), Metall-Pulver, -Plättchen und -Fasern sowie metallisierten Glas- oder Kohlenstoffasern versetzen.The shielding of electromagnetic radiation in the frequency range from 10 kHz to 10 GHz is of increasing importance e.g. in the future development of plastic computer housings. In order to provide plastics with shielding, they can be mixed with conductive fillers such as graphite (soot), metal powder, platelets and fibers as well as metallized glass or carbon fibers.

Aus der DE-B-27 43 768 sind mit Nickel oder Kupfer metallisierte Polyacrylnitril- und Baumwollfasern-Fasern bekannt.DE-B-27 43 768 discloses polyacrylonitrile and cotton fiber fibers metallized with nickel or copper.

In der DE-A-38 10 597 werden Verbundwerkstoffe beschrieben, die metallisierte Fasern enthalten. Als Fasern werden Glasfasern, Aramidfasern und Kohlenstoffasern verwendet, die auf herkömmliche Art, beispielsweise durch stromloses oder galvanisches Metallisieren, durch Sputtern oder Bedampfen, metallisiert werden können. Die metallisierten Fasern sind gemäß DE-A 38 10 597 mit einer polymeren Schutzschicht versehen.DE-A-38 10 597 describes composite materials which contain metallized fibers. Glass fibers, aramid fibers and carbon fibers are used as fibers, which can be metallized in a conventional manner, for example by electroless or galvanic metallization, by sputtering or vapor deposition. According to DE-A 38 10 597, the metallized fibers are provided with a polymer protective layer.

Die US-A-4,803,097 beschreibt ein Verfahren zur Aufbringung einer Metallschicht auf natürliche oder künstliche Materialien, wobei das zu beschichtende Material (a) zunächst einer Ozonatmosphäre ausgesetzt, dann (b) mit einem Lösungsmittel im basischen Milieu konditioniert, anschließend (c) mit einem Oxidationsmittel in Kontakt gebracht, (d) daraufhin mit einer Metallschicht versehen, und (e) schließlich erhitzt wird. Vor dem Aufbringen der Metallschicht muß das zu beschichtende Material mit Edelmetallkeimen aktiviert werden.US-A-4,803,097 describes a method for applying a metal layer to natural or artificial materials, the material to be coated (a) first being exposed to an ozone atmosphere, then (b) conditioned with a solvent in a basic medium, then (c) with a Oxidizing agent contacted, (d) then provided with a metal layer, and (e) finally heated. Before applying the metal layer, the material to be coated must be activated with noble metal seeds.

Nachteilig an den bislang bekannten leitfähigen Füllstoffen für Kunststoffe sind die teilweise zu hohen spezifischen Dichten, zu niedrigen Flexibilitäten, nicht ausreichenden thermischen Beständigkeiten, mangelnden Flammschutzeigenschaften sowie kostenungünstigen Herstellverfahren.Disadvantages of the previously known conductive fillers for plastics are that the specific densities are sometimes too high, the flexibility is too low, the thermal resistance is insufficient, the flame-retardant properties are inadequate, and the manufacturing process is inexpensive.

Aufgabe der vorliegenden Erfindung war es daher, metallisierte Fasern herzustellen, die die genannten Nachteile nicht aufweisen.The object of the present invention was therefore to produce metallized fibers which do not have the disadvantages mentioned.

Demgemäß wurde ein Verfahren zur Herstellung metallbeschichteter Melamin-Formaldehyd-Harz-Fasern gefunden, durch

Ia
Aktivieren der Faseroberflächen durch Behandlung der Fasern mit einer wässrigen Lösung, die ein wasserlösliches Übergangsmetallsalz, ausgenommen Edelmetallsalz, und ein unedleres Metall oder Metallsalz als Reduktionsmittel enthält, oder
Ib
Aktivieren der Faseroberflächen durch Behandlung der Fasern mit einer wässrigen Lösung, die ein wasserlösliches Übergangsmetallsalz, ausgenommen Edelmetallsalz, ein Komplexierungsmittel und eine Hydridverbindung als Reduktionsmittel enthält,
II
gegebenenfalls weitere reduzierende Behandlung mit Reduktionsmitteln zur Überführung abgeschiedener niederer Oxidationsstufen in den metallischen Zustand
III
anschließendes Beschichten der aktivierten Fasern durch Behandlung der Fasern mit einer wässrigen Lösung, wie ein wasserlösliches Übergangsmetallsalz, ein Komplexierungsmittel und ein Reduktionsmittel enthält.
Accordingly, a process for producing metal-coated melamine-formaldehyde resin fibers has been found by
Yes
Activating the fiber surfaces by treating the fibers with an aqueous solution which contains a water-soluble transition metal salt, except noble metal salt, and a base metal or metal salt as a reducing agent, or
Ib
Activating the fiber surfaces by treating the fibers with an aqueous solution which contains a water-soluble transition metal salt, with the exception of noble metal salt, a complexing agent and a hydride compound as reducing agent,
II
if necessary, further reducing treatment with reducing agents to convert deposited lower oxidation states into the metallic state
III
then coating the activated fibers by treating the fibers with an aqueous solution, such as a water-soluble transition metal salt, containing a complexing agent and a reducing agent.

Außerdem wurden Fasern, hergestellt nach dem erfindungsgemäßen Verfahren, die Verwendung dieser Fasern zur Herstellung von Verbundwerkstoffen sowie Verbundwerkstoffe, die diese Fasern enthalten, gefunden.In addition, fibers produced by the process according to the invention, the use of these fibers for the production of composite materials and composite materials containing these fibers were found.

Fasern aus Melamin-Formaldehyd-Kondensaten sowie deren Herstellung sind beispielsweise aus der DE-B-23 64 091, der EP-B 93965 und "Chemiefasern/Textilindustrie", 40./92. Jahrgang, 12/90, T154, bekannt. In der Regel enthalten diese Fasern mindestens 80 Gew.-% eines Melamin-Formaldehyd-Vorkondensates, das aus Melamin und Formaldehyd im Molverhältnis Melamin zu Formaldehyd von 1:1,5 bis 1:4,5 aufgebaut ist, und zusätzlich bis zu 20 Gew.-% andere amino-, amid-, hydroxyl- oder carboxylgruppenhaltige Duroplastbildner einerseits und Aldehyde andererseits. Die Fasern kann man dann daraus nach üblichen Verfahren, wie sie beispielsweise in der oben angegebenen Literatur beschrieben ist, herstellen.Fibers made from melamine-formaldehyde condensates and their production are known, for example, from DE-B-23 64 091, EP-B 93965 and "Chemical fibers / textile industry", 40./92. Vintage, 12/90, T154, known. As a rule, these fibers contain at least 80% by weight of a melamine-formaldehyde precondensate, which is composed of melamine and formaldehyde in a molar ratio of melamine to formaldehyde of 1: 1.5 to 1: 4.5, and additionally up to 20% by weight .-% other amino, amide, hydroxyl or carboxyl group-containing thermoset on the one hand and aldehydes on the other. The fibers can then be produced therefrom by customary methods, as described, for example, in the literature cited above.

Im allgemeinen verwendet man Melamin-Formaldehyd-Harz-Fasern mit einem Durchmesser von 5 bis 100 µm, bevorzugt von 8 bis 20 µm. Für die Beschichtung kann man sowohl Endlosfasern (rovings) als auch Faserschnitzel mit einer Länge von 1 bis 200, vorzugsweise von 1 bis 50 mm, verwenden.Melamine-formaldehyde resin fibers with a diameter of 5 to 100 μm, preferably 8 to 20 μm, are generally used. Both continuous fibers (rovings) and fiber chips with a length of 1 to 200, preferably 1 to 50 mm, can be used for the coating.

Man kann aber auch aus den Fasern hergestellte flächige Gebilde wie Gewebe, Gewirke oder Vliese verwenden.However, it is also possible to use sheet-like structures such as woven, knitted or non-woven fabrics made from the fibers.

Als Metalle zur Beschichtung der Fasern kann man prinzipiell alle Übergangsmetalle einsetzen. Beispielhaft seien genannt: Chrom, Molybdän, Wolfram, Mangan, Eisen, Cobalt, Nickel, Palladium, Platin, Kupfer, Silber und Gold, bevorzugt Molybdän, Cobalt, Nickel, Palladium, Platin, Kupfer, Silber und Gold, besonders bevorzugt Nickel, Kupfer, Molybdän, Palladium, Silber, Platin und Gold.In principle, all transition metals can be used as metals for coating the fibers. Examples include: chromium, molybdenum, tungsten, manganese, iron, cobalt, nickel, palladium, platinum, copper, silver and gold, preferably molybdenum, cobalt, nickel, palladium, platinum, copper, silver and gold, particularly preferably nickel, copper , Molybdenum, palladium, silver, platinum and gold.

Die Dicke der Metallbeschichtung wählt man in der Regel von 0,01 bis 1, vorzugsweise von 0,2 bis 0,5 µm.The thickness of the metal coating is generally chosen from 0.01 to 1, preferably from 0.2 to 0.5 μm.

Das Gewichtsverhältnis von Faser zu Metall wählt man im allgemeinen zwischen 100:1 bis 0,5:1, bevorzugt von 4:1 bis 1:1.The weight ratio of fiber to metal is generally chosen between 100: 1 to 0.5: 1, preferably from 4: 1 to 1: 1.

Die Metallbeschichtung in wäßriger Lösung nimmt man in der Regel so vor, daß man die Oberfläche der Fasern in einer ersten Stufe zuerst mit Metallkeimen versieht ("aktiviert"), und anschließend auf dieser Schicht das gewünschte Metall abscheidet. Man kann die Beschichtung auch durch Zersetzung von Übergangsmetallcarbonylverbindungen in an sich bekannter Weise wie Thermolyse (Chemical Vapor Deposition) oder Photolyse in Gegenwart der Melaminharzfasern durchführen.The metal coating in aqueous solution is generally carried out by first providing the surface of the fibers with metal nuclei (“activated”) and then depositing the desired metal on this layer. The coating can also be carried out by decomposing transition metal carbonyl compounds in a manner known per se, such as thermolysis (chemical vapor deposition) or photolysis in the presence of the melamine resin fibers.

Die Aktivierung oder Erstbeschichtung der Melaminfasern kann man in an sich bekannter Weise dadurch erreichen, daß man die Fasern mit einer wäßrigen Lösung, enthaltend ein wasserlösliches Metallsalz, ausgenommen Edelmetallsalz und ein weiteres, unedleres Metallsalz als Reduktionsmittel, behandelt (s. z.B. WO-A-89/06710).The activation or first coating of the melamine fibers can be achieved in a manner known per se by treating the fibers with an aqueous solution containing a water-soluble metal salt, with the exception of the noble metal salt and another, less noble metal salt as reducing agent (see, for example, WO-A-89 / 06710).

Als Metallsalze kommen beispielsweise die wasserlöslichen Salze von Kupfer in Betracht wie Kupfer-(I)-chlorid und Kupfer-(II)-sulfat.Examples of suitable metal salts are the water-soluble salts of copper, such as copper (I) chloride and copper (II) sulfate.

Als Reduktionsmittel verwendet man bevorzugt Zinn-(II)-chlorid oder Titan-(III)-chlorid.Tin (II) chloride or titanium (III) chloride is preferably used as the reducing agent.

Das Metallsalz setzt man vorzugsweise in Form seiner wäßrigen Lösung in Konzentrationen von 0,1 bis 5, bevorzugt von 0,2 bis 0,5 g/l ein. Das Molverhältnis von Reduktionsmittel zu Metallsalz beträgt in der Regel 1:1 bis 4:1, bevorzugt von 1:1 bis 2:1.The metal salt is preferably used in the form of its aqueous solution in concentrations of 0.1 to 5, preferably 0.2 to 0.5 g / l. The molar ratio of reducing agent to metal salt is generally 1: 1 to 4: 1, preferably from 1: 1 to 2: 1.

Die Fasern setzt man im allgemeinen in Mengen von 0,1 bis 10, bevorzugt von 0,5 bis 1 Gew.-% (bezogen auf die Wassermenge) ein.The fibers are generally used in amounts of 0.1 to 10, preferably 0.5 to 1% by weight (based on the amount of water).

Man führt die Reaktion im allgemeinen bei Raumtemperatur und unter Atmosphärendruck durch, man kann aber auch beispielsweise höhere Temperaturen und Drücke wählen, bevorzugt bis 95°C und bis 500 kPa.The reaction is generally carried out at room temperature and under atmospheric pressure, but it is also possible, for example, to choose higher temperatures and pressures, preferably up to 95 ° C. and up to 500 kPa.

Der pH-Bereich zu Beginn der Aktivierung ist im allgemeinen unkritisch und hängt im wesentlichen nur von den eingesetzten Substanzen und deren jeweiliger Menge ab.The pH range at the beginning of the activation is generally not critical and essentially depends only on the substances used and their respective amounts.

Man kann Melaminharzfasern auch dadurch aktivieren, daß man sie mit einer wäßrigen Lösung, enthaltend ein wasserlösliches Metallsalz, ausgenommen Edelmetallsalz ein Komplexierungsmittel und eine Hydridverbindung als Reduktionsmittel, behandelt.Melamine resin fibers can also be activated by treating them with an aqueous solution containing a water-soluble metal salt, with the exception of the noble metal salt, a complexing agent and a hydride compound as reducing agent.

Hierbei stellt man im allgemeinen zunächst eine wäßrige Lösung bestehend aus dem Metallsalz und dem Komplexbildner her. Nachdem sich ein konstanter pH-Wert eingestellt hat, gibt man die Fasern zu, und fügt anschließend, zweckmäßigerweise portionsweise, das Reduktionsmittel so zu, bis eine Ausfällung des Metalls an der Eintropfstelle eintritt. Danach rührt oder schüttelt man die Lösung, bis keine weitere Aufhellung der Lösung beobachtbar ist. Hierbei tritt in der Regel eine Verfärbung der Fasern ein. Im allgemeinen wiederholt man den Vorgang der Zugabe des Reduktionsmittels solange, bis keine weitere Farbvertiefung der Fasern erkennbar ist. Vorzugsweise gibt man soviel des Reduktionsmittels zu, bis der pH-Wert der Lösung um 1 bis 2 Einheiten, bevorzugt 1,25 bis 1,75 Einheiten erhöht ist.In general, an aqueous solution consisting of the metal salt and the complexing agent is first prepared. After a constant pH has been established, the fibers are added, and the reducing agent is then added, advantageously in portions, until the metal precipitates at the point of dropping. The solution is then stirred or shaken until no further brightening of the solution is observed. As a rule, the fibers become discolored. In general, the process of adding the reducing agent is repeated until no further deepening of the color of the fibers is discernible. As much of the reducing agent is preferably added until the pH of the solution is increased by 1 to 2 units, preferably 1.25 to 1.75 units.

Als Metallsalze kann man prinzipiell alle wasserlöslichen Übergangsmetallsalze ausgenommen Edelmetallsalze einsetzen. Beispielhaft seien genannt: Cobalt-(II)-chlorid, Nickel-(II)-chlorid, Kupfer-(II)-sulfat, bevorzugt Nikkel-(II)-chlorid, Kupfer-(II)-sulfat, besonders bevorzugt Kupfer-(II)-sulfat.In principle, all water-soluble transition metal salts with the exception of noble metal salts can be used as metal salts. Examples include: cobalt (II) chloride, nickel (II) chloride, copper (II) sulfate, preferably nickel (II) chloride, Copper (II) sulfate, particularly preferably copper (II) sulfate.

Als Komplexierungsmittel kann man in der Regel organische Komplexbildner verwenden wie Carbonsäuren oder Carbonsäurederivate, beispielsweise Zitronensäure, Tri-Natriumcitrat, Natriumacetat, Salicylsäure, Kalium-Natrium-Tartrat, Bernsteinsäure, Glycin, L-Asparaginsäure, L-Glutaminsäure, Alkohole oder Alkoholderivate, beispielsweise Glycerin, 1,3-Propandiol, Ethylenglykol, 3-Amino-1-propanol, Mannit, sowie Acetylaceton, 2-Propanthiol, Acetessigsäureethylester, Ethylendiamintetraacetat ("EDTA"), Biuret oder Kronenether wie 15-Crown-5 und 18-Crown-6, bevorzugt Zitronensäure, Tri-Natriumcitrat, Glycin, besonders bevorzugt Zitronensäure.Organic complexing agents such as carboxylic acids or carboxylic acid derivatives, for example citric acid, trisodium citrate, sodium acetate, salicylic acid, potassium sodium tartrate, succinic acid, glycine, L-aspartic acid, L-glutamic acid, alcohols or alcohol derivatives, for example glycerol, can generally be used as complexing agents , 1,3-propanediol, ethylene glycol, 3-amino-1-propanol, mannitol, and also acetylacetone, 2-propanethiol, ethyl acetoacetate, ethylenediaminetetraacetate ("EDTA"), biuret or crown ethers such as 15-crown-5 and 18-crown-6 , preferably citric acid, trisodium citrate, glycine, particularly preferably citric acid.

Als Hydridverbindung bei der Aktivierung setzt man im allgemeinen Natriumborhydrid oder den Boran-Dimethylamin-Komplex, vorzugsweise Natriumborhydrid ein.The hydride compound used for the activation is generally sodium borohydride or the borane-dimethylamine complex, preferably sodium borohydride.

Das Metallsalz kann man in einem Konzentrationsbereich von 0,01 bis 1, vorzugsweise von 0,05 bis 0,2 g/l einsetzen.The metal salt can be used in a concentration range from 0.01 to 1, preferably from 0.05 to 0.2 g / l.

Die Fasern setzt man im allgemeinen in Mengen von 0,1 bis 10, bevorzugt von 0,5 bis 1 Gew.-% (bezogen auf die Wassermenge) ein.The fibers are generally used in amounts of 0.1 to 10, preferably 0.5 to 1% by weight (based on the amount of water).

Die Menge des Komplexierungsmittels beträgt in der Regel von 100 bis 400, vorzugsweise von 100 bis 200 mol-% (bezogen auf das Metallsalz).The amount of the complexing agent is generally from 100 to 400, preferably from 100 to 200 mol% (based on the metal salt).

Die Menge des Reduktionsmittels wählt man im allgemeinen in einem Bereich von 100 bis 400, bevorzugt von 100 bis 200 mol-% (bezogen auf das Metallsalz).The amount of reducing agent is generally chosen in a range from 100 to 400, preferably from 100 to 200 mol% (based on the metal salt).

Die Reaktion führt man in der Regel in einem Temperaturbereich von 10 bis 50 , bevorzugt von 15 bis 35°C unter Atmosphärendruck durch.The reaction is usually carried out in a temperature range from 10 to 50, preferably from 15 to 35 ° C. under atmospheric pressure.

Der pH-Wert zu Beginn der Reaktion ist im wesentlichen abhängig vom gewählten Metallsalz und ist in der Regel kleiner als pH 7.The pH at the start of the reaction is essentially dependent on the metal salt selected and is generally less than pH 7.

Die Dauer der Aktivierung ist unkritisch. Man wählt sie in der Regel im Bereich von 30 bis 300, bevorzugt von 50 bis 120 min.The duration of the activation is not critical. They are usually selected in the range from 30 to 300, preferably from 50 to 120, minutes.

Verwendet man ein Kupfersalz, so bildet sich in der Regel auf der Faseroberfläche zunächst eine Schicht aus Cu-(I)-oxid aus, welches man gewöhnlich mit einer basischen, wäßrigen Reduktionslösung zu metallischem Kupfer weiterreduziert. Als Reduktionsmittel verwendet man dabei bevorzugt eine Hydridverbindung. Bei der Reduktion zum Metall tritt in der Regel eine Verfärbung der Fasern ein. Im allgemeinen wiederholt man den Vorgang der Zugabe der Reduktionslösung solange, bis keine weitere Farbvertiefung der Fasern erkennbar ist.If a copper salt is used, a layer of Cu (I) oxide usually forms on the fiber surface, which is usually further reduced to metallic copper with a basic, aqueous reducing solution. A hydride compound is preferably used as the reducing agent. When reducing to metal, the fibers usually become discolored. In general, the process of adding the reducing solution is repeated until no further deepening of the color of the fibers is discernible.

Als Hydridverbindung bei der Reduktion von Cu-(I)-oxid setzt man im allgemeinen Natriumborhydrid oder den Boran-Dimethylamin-Komplex, vorzugsweise Natriumborhydrid ein.The hydride compound used in the reduction of Cu (I) oxide is generally sodium borohydride or the borane-dimethylamine complex, preferably sodium borohydride.

Als Base in der Lösung zur Reduktion von Cu-(I)-oxid verwendet man im allgemeinen ein Alkalimetall- oder Erdalkalimetall-Hydroxid oder -Oxid wie Lithiumhydroxid, Natriumhydroxid, Kaliumhydroxid, Natriumoxid, Magnesiumhydroxid oder Calciumhydroxid, bevorzugt Natriumhydroxid und Kaliumhydroxid.An alkali metal or alkaline earth metal hydroxide or oxide such as lithium hydroxide, sodium hydroxide, potassium hydroxide, sodium oxide, magnesium hydroxide or calcium hydroxide, preferably sodium hydroxide and potassium hydroxide, is generally used as the base in the solution for the reduction of Cu (I) oxide.

Die Menge der Hydridverbindung in der Lösung zur Reduktion von Cu-(I)-oxid wählt man gewöhnlich im Bereich von 1 bis 5 g/l Wasser. Die Menge der Base wählt man in der Regel im Bereich von 0,1 bis 1 g/l Wasser.The amount of the hydride compound in the solution for reducing Cu (I) oxide is usually selected in the range from 1 to 5 g / l of water. The amount of base is usually chosen in the range from 0.1 to 1 g / l water.

Die Reduktion des Cu-(I)-oxids führt man in der Regel in einem Temperaturbereich von 10 bis 50, bevorzugt von 15 bis 35°C unter Atmosphärendruck durch.The reduction of the Cu (I) oxide is generally carried out in a temperature range from 10 to 50, preferably from 15 to 35 ° C. under atmospheric pressure.

Den pH-Wert der Lösung zur Reduktion des Cu-(I)-oxids wählt man im allgemeinen im Bereich von 7 bis 14, bevorzugt von 10 bis 12.The pH of the solution for reducing the Cu (I) oxide is generally selected in the range from 7 to 14, preferably from 10 to 12.

In der Regel wählt man die Dauer der Cu-(I)-oxid-Reduktion im Bereich von 30 bis 300, bevorzugt von 60 bis 120 min.As a rule, the duration of the Cu (I) oxide reduction is selected in the range from 30 to 300, preferably from 60 to 120, minutes.

Die eigentliche Beschichtung der Melaminharzfasern nimmt man im allgemeinen so vor, daß man die nach den oben beschriebenen Methoden vorbehandelten Melamin-Harzfasern mit einer wäßrigen Lösung, enthaltend ein wasserlösliches Metallsalz, ein Komplexierungsmittel und ein Reduktionsmittel, behandelt.The actual coating of the melamine resin fibers is generally carried out by treating the melamine resin fibers pretreated by the methods described above with an aqueous solution containing a water-soluble metal salt, a complexing agent and a reducing agent.

Hierzu stellt man in der Regel zuerst eine Lösung aus dem wasserlöslichen Metallsalz in Wasser her und gibt dann den Komplexbildner zu. Anschließend stellt man im allgemeinen den für die Reduktion günstigen pH-Wert ein und fügt dann das Reduktionsmittel, bevorzugt als wäßrige Lösung, zu. Danach kann man die Melaminharz-Fasern zugeben, wobei die Zugabe der Fasern diskontinuierlich oder kontinuierlich erfolgen kann.For this purpose, as a rule, a solution is first prepared from the water-soluble metal salt in water and then the complexing agent is added. Subsequently, the pH which is favorable for the reduction is generally set and the reducing agent is then added, preferably as an aqueous one Solution, too. The melamine resin fibers can then be added, and the fibers can be added batchwise or continuously.

Als Metallsalz kann man prinzipiell alle wasserlöslichen Übergangsmetallsalze einsetzen. Beispielhaft seien genannt: Cobalt-(II)-chlorid, Nickel-(II)-chlorid, Palladium-(II)-chlorid, Platin-(II)-chlorid, Kupfer-(II)-sulfat, Silbernitrat und Gold-(III)-chlorid, bevorzugt Nikkel-(II)-chlorid, Palladium-(II)-chlorid, Platin-(II)-chlorid, Kupfer-(II)-sulfat, Silbernitrat und Gold-(III)-chlorid, besonders bevorzugt Palladium-(II)-chlorid, Kupfer-(II)-sulfat, Silbernitrat und Gold-(III)-chlorid.In principle, all water-soluble transition metal salts can be used as the metal salt. Examples include: cobalt (II) chloride, nickel (II) chloride, palladium (II) chloride, platinum (II) chloride, copper (II) sulfate, silver nitrate and gold (III ) chloride, preferably nickel (II) chloride, palladium (II) chloride, platinum (II) chloride, copper (II) sulfate, silver nitrate and gold (III) chloride, particularly preferably palladium - (II) chloride, copper (II) sulfate, silver nitrate and gold (III) chloride.

Als Komplexierungsmittel verwendet man im allgemeinen Tartrate wie Kalium-Natrium-Tartrat, Dikaliumtartrat, Dinatriumtartrat, Kaliumtartrat, Natriumtartrat oder Diammoniumtartrat, Tri-Natriumcitrat sowie EDTA.Tartrates such as potassium sodium tartrate, dipotassium tartrate, disodium tartrate, potassium tartrate, sodium tartrate or diammonium tartrate, trisodium citrate and EDTA are generally used as complexing agents.

Als Reduktionsmittel nimmt man in der Regel Formaldehyd, zweckmäßig in Form einer wäßrigen Lösung, Natriumborhydrid, Boran-Dimethylamin-Komplex, Natriumhypophosphit (NaH2PO2·H2O) oder Hydrazin. Bevorzugt verwendet man Natriumborhydrid zur Reduktion von Kupfer und Nickel, Formaldehyd zur Reduktion von Kupfer und Silber,
Boran-Dimethylamin-Komplex und Natriumhypophosphit zur Reduktion von Nickel.The reducing agent used is generally formaldehyde, advantageously in the form of an aqueous solution, sodium borohydride, borane-dimethylamine complex, sodium hypophosphite (NaH 2 PO 2 .H 2 O) or hydrazine. Sodium borohydride is preferably used to reduce copper and nickel, formaldehyde to reduce copper and silver,
Borane-dimethylamine complex and sodium hypophosphite for the reduction of nickel.

Die Wahl des pH-Bereiches hängt im wesentlichen von der Wahl des Reduktionsmittels ab. So wählt man im allgemeinen bei der Reduktion mit Formaldehyd einen pH-Bereich von 10 bis 14, wobei man die Lösung in der Regel mit Alkalimetallhydroxiden oder -oxiden, z.B. Natrium- oder Kaliumhydroxid, basisch macht. Bei der Reduktion mit Hypophosphit und mit Boran-Dimethylamin-Komplex wählt man bevorzugt einen pH-Bereich von 5 bis 10. Die Einstellung des pH-Wertes nimmt man hierbei im allgemeinen mit in diesen Bereichen üblichen Puffersystemen, z.B. NH3/NH4Cl oder Essigsäure/Natriumacetat, vor. Bei der Reduktion mit Natriumborhydrid arbeitet man gewöhnlich in einem pH-Bereich von 7 bis 14, wobei man die Reduktionslösung in der Regel mit Alkalimetallhydroxiden oder -oxiden, z.B. Natrium- oder Kaliumhydroxid, basisch macht.The choice of pH range essentially depends on the choice of reducing agent. In general, a pH range from 10 to 14 is chosen for the reduction with formaldehyde, the solution generally being made basic with alkali metal hydroxides or oxides, for example sodium or potassium hydroxide. For the reduction with hypophosphite and with borane-dimethylamine complex, a pH range from 5 to 10 is preferably selected. The pH is generally adjusted using buffer systems which are customary in these areas, for example NH 3 / NH 4 Cl or Acetic acid / sodium acetate. The reduction with sodium borohydride is usually carried out in a pH range from 7 to 14, the reduction solution generally being made basic with alkali metal hydroxides or oxides, for example sodium or potassium hydroxide.

Das Metallsalz kann man in einem Konzentrationsbereich von 5 bis 200, vorzugsweise von 10 bis 50 g/l einsetzen.The metal salt can be used in a concentration range from 5 to 200, preferably from 10 to 50 g / l.

Die Fasern setzt man im allgemeinen in Mengen von 0,1 bis 10, bevorzugt von 0,3 bis 1 Gew.-% (bezogen auf die Wassermenge) ein.The fibers are generally used in amounts of 0.1 to 10% by weight, preferably 0.3 to 1% by weight (based on the amount of water).

Die Menge des Komplexierungsmittels beträgt in der Regel 100 bis 400, vorzugsweise 100 bis 200 mol-% (bezogen auf das Metallsalz).The amount of the complexing agent is usually 100 to 400, preferably 100 to 200 mol% (based on the metal salt).

Die Menge des Reduktionsmittels wählt man im allgemeinen in einem Bereich von 100 bis 400, bevorzugt von 100 bis 200 mol-% (bezogen auf das Metall-salz).The amount of reducing agent is generally chosen in a range from 100 to 400, preferably from 100 to 200 mol% (based on the metal salt).

Die Wahl der Temperatur hängt im allgemeinen vom jeweiligen Metall ab. In der Regel kann man die Metallisierung in einem Temperaturbereich von 15 bis 95, bevorzugt von 15 bis 35°C und unter Atmosphärendruck durchführen. Bevorzugt für die Metallisierung mit Nickel ist ein Temperaturbereich von 60 bis 95°C, und für die Metallisierung mit Silber ein Temperaturbereich von 50 bis 80°C.The choice of temperature generally depends on the metal in question. As a rule, the metallization can be carried out in a temperature range from 15 to 95, preferably from 15 to 35 ° C. and under atmospheric pressure. A temperature range from 60 to 95 ° C. is preferred for the metallization with nickel, and a temperature range from 50 to 80 ° C. for the metallization with silver.

Die Dauer der Metallisierung hängt im wesentlichen von der gewünschten Schichtdicke und von den gewählten Konzentrationen der Ausgangsstoffe ab. Man wählt sie in der Regel im Bereich von 30 bis 300, bevorzugt von 60 bis 120 min.The duration of the metallization essentially depends on the desired layer thickness and on the selected concentrations of the starting materials. They are generally chosen in the range from 30 to 300, preferably from 60 to 120, minutes.

Die erfindungsgemäßen metallbeschichteten Melamin-Harzfasern kann man in an sich üblicher Weise zusammen mit anderen polymeren Formmassen wie Thermoplasten und Duroplasten zu Verbundwerkstoffen verarbeiten.The metal-coated melamine resin fibers according to the invention can be processed in a conventional manner together with other polymeric molding compositions such as thermoplastics and thermosets to form composite materials.

Zur Herstellung von Verbundwerkstoffen mit Thermoplasten arbeitet man nach an sich bekannten Verfahren. Beispielsweise kann man den Thermoplast in einem heizbaren Mischaggregat aufschmelzen und in die Schmelze die erfindungsgemäßen metallisierten Melamin-Harzfasern als Endlosfasern (rovings) oder als Faserschnitzel (chopped strang) einarbeiten. Anschließend kann man die Schmelze als Strang extrudieren, spritzgießen oder pressen.For the production of composite materials with thermoplastics one works according to known methods. For example, the thermoplastic can be melted in a heatable mixing unit and the metallized melamine resin fibers according to the invention can be incorporated into the melt as continuous fibers (rovings) or as fiber chips (chopped strand). The melt can then be extruded, injection molded or pressed as a strand.

Die Herstellung von Verbundwerkstoffen mit Duroplasten erfolgt in der Regel ebenfalls nach üblichen Methoden, beispielsweise indem man die erfindungsgemäßen Melaminharzfasern mit den flüssigen Ausgangsmaterialien imprägniert und anschließend härtet.The production of composite materials with thermosets is generally also carried out by customary methods, for example by impregnating the melamine resin fibers according to the invention with the liquid starting materials and then curing them.

Als Polymermatrix können alle bekannten Thermoplasten und Duroplasten sowie deren Mischungen eingesetzt werden. Beispielhaft seien genannt Polyamide, Polyvinylchlorid, Polyolefine, Polyester, aromatische Polyether, ungesättigte Polyesterharze und Polyurethane.All known thermoplastics and thermosets and their mixtures can be used as the polymer matrix. Examples include polyamides, polyvinyl chloride, polyolefins, polyesters, aromatic polyethers, unsaturated polyester resins and polyurethanes.

Den Anteil der erfindungsgemäßen Melamin-Harzfasern wählt man in der Regel im Bereich von 1 bis 40, vorzugsweise von 5 bis 25 Gew.-%, bezogen auf das Gewicht des Verbundwerkstoffs.The proportion of the melamine resin fibers according to the invention is generally selected in the range from 1 to 40, preferably from 5 to 25,% by weight, based on the weight of the composite material.

Die erfindungsgemäßen Verbundwerkstoffe können außerdem noch die üblichen Zusatzstoffe und Verarbeitungshilfsmittel wie Stabilisatoren, Flammschutzmittel, Schlagzähmodifizierer, Antioxidantien, Gleitstoffe, Füllstoffe sowie Farbstoffe und Pigmente sowie Ruß und/oder Graphit enthalten.The composite materials according to the invention can also contain the usual additives and processing aids such as stabilizers, flame retardants, impact modifiers, antioxidants, lubricants, fillers and dyes and pigments as well as carbon black and / or graphite.

Die erfindungsgemäßen Melaminharz-Fasern zeichnen sich gegenüber bekannten metallisierten Fasern oder Metallfasern durch ihr geringes spezifisches Gewicht, ihre hohe Flexibilität, ihre kostengünstige Herstellung, ihre ausgezeichneten Flammschutzeigenschaften sowie ihre sehr gute thermische Beständigkeit aus.The melamine resin fibers according to the invention are distinguished from known metallized fibers or metal fibers by their low specific weight, their high flexibility, their cost-effective production, their excellent flame retardant properties and their very good thermal resistance.

BeispieleExamples

Die Metallgehaltsbestimmungen der Fasern in den folgenden Versuchen erfolgte mittels Atomabsorptionsspektroskopie.The metal content determination of the fibers in the following experiments was carried out by means of atomic absorption spectroscopy.

Die Leitfähigkeit wurde mit einer Vierpunktemethode an Einzelfasern bestimmt. Hierzu wurde mittels zweier Platinelektroden (Paar A), die einen Abstand von ca. 1cm voneinander hatten und mit der Faseroberfläche verbunden waren, ein Strom von 100 mA durch die Faser geleitet. In dem Bereich zwischen den beiden Elektroden wurden dann zwei weitere Elektroden (Paar B) im Abstand von 0,33 cm voneinander angebracht. Mittels des Elektrodenpaars B wurde die Spannung U gemessen.The conductivity was determined using a four-point method on single fibers. For this purpose, a current of 100 mA was passed through the fiber by means of two platinum electrodes (pair A) which were at a distance of approximately 1 cm from one another and were connected to the fiber surface. Two further electrodes (pair B) were then placed at a distance of 0.33 cm from one another in the area between the two electrodes. The voltage U was measured by means of the pair of electrodes B.

Aus den bekannten Größen - Strom I, Abstand der Elektroden (Paar B) 1, Querschnitt des Leiters q - und der gemessenen Spannung U, kann man dann die spezifische Leitfähigkeit der Faser, κFaser, gemäß der Gleichung 1 bestimmen: κ Faser = I.1/(U·q)

Figure imgb0001
From the known quantities - current I, distance of the electrodes (pair B) 1, cross section of the conductor q - and the measured voltage U, the specific conductivity of the fiber, κ fiber , can then be determined according to equation 1: κ fiber = I.1 / (Uq)
Figure imgb0001

Der Querschnitt der Fasern wurde mittels der Dichte ρm = 2,42 g/cm3, der eingewogenen Menge m und der Länge der Faser gemäß Gleichung 2 berechnet: q = m/(ρ m ·l Faser )

Figure imgb0002
The cross section of the fibers was calculated using the density ρ m = 2.42 g / cm 3 , the weighed quantity m and the length of the fiber according to equation 2: q = m / (ρ m · L fiber )
Figure imgb0002

Beispiel 1example 1 Herstellung Kupfer-beschichteter MelaminharzfasernManufacture of copper-coated melamine resin fibers

  • (a) Aktivierung der Melaminharzfasern
    Zu einer Lösung aus 0,063 g (0,25 mmol) Kupfer-(II)-sulfat-pentahydrat, 0,053 g (0,25 mmol) Zitronensäure und 200 ml Wasser wurden 1 g Melaminharzfasern (Basofil® O, BASF) gegeben. Anschließend wurde die Lösung während 30 min unter Rühren portionsweise mit 1,47 g (0,4 mmol) einer 1 gew.-%igen Natriumborhydrid-Lösung versetzt, wobei eine Farbänderung der Fasern von weiß nach gelbbraun beobachtet wurde. Danach wurden die Fasern mit Wasser gewaschen. Der pH-Wert bei Reaktionsbeginn betrug 3,1 und 4,6 bei Reaktionsende.     (a) Activation of the melamine resin fibers
    1 g of melamine resin fibers (Basofil® O, BASF) was added to a solution of 0.063 g (0.25 mmol) of copper (II) sulfate pentahydrate, 0.053 g (0.25 mmol) of citric acid and 200 ml of water. Subsequently, 1.47 g (0.4 mmol) of a 1% strength by weight sodium borohydride solution were added to the solution in portions over a period of 30 minutes, with a change in the color of the fibers from white to yellow-brown being observed. The fibers were then washed with water. The pH at the start of the reaction was 3.1 and 4.6 at the end of the reaction.
  • (b) Reduktion der Kupfer-(I)-oxid-Schicht
    Die nach (a) erhaltenen Fasern wurden eine Stunde lang in eine Lösung aus 1,0 g (26 mmol) Natriumborhydrid, 0,1 g (2,5 mmol) Natriumhydroxid und 300 ml Wasser gelegt. Danach wurden die Fasern mit Wasser gewaschen.     (b) Reduction of the copper (I) oxide layer
    The fibers obtained in (a) were placed in a solution of 1.0 g (26 mmol) of sodium borohydride, 0.1 g (2.5 mmol) of sodium hydroxide and 300 ml of water for one hour. The fibers were then washed with water.
  • (c) Verkupferung der Melaminharzfasern
    Eine Mischung aus 4,32 g (17,3 mmol) Kupfer-(II)-sulfat-pentahydrat, 9,66 g (34 mmol) Kaliumnatriumtartrat, 0,95 g (23,8 mmol) Natriumhydroxid und 300 ml Wasser wurde mit einer Mischung aus 4,4 g (54 mmol) einer 37 gew.-%igen Formalin-Lösung und 43 ml (107 mmol) einer 10 gew.-%igen Natriumhydroxid-Lösung versetzt. Anschließend wurden die unter (b) erhaltenen Fasern zugegeben und zwei Stunden unter leichtem Rühren verkupfert. Danach wurden die verkupferten Fasern mit Wasser und Ethanol gewaschen und bei Raumtemperatur an der Luft getrocknet.     (c) Copper plating of the melamine resin fibers
    A mixture of 4.32 g (17.3 mmol) copper (II) sulfate pentahydrate, 9.66 g (34 mmol) potassium sodium tartrate, 0.95 g (23.8 mmol) sodium hydroxide and 300 ml water was added a mixture of 4.4 g (54 mmol) of a 37% by weight formalin solution and 43 ml (107 mmol) of a 10% by weight sodium hydroxide solution. The fibers obtained under (b) were then added and copper-plated for two hours with gentle stirring. The copper-coated fibers were then washed with water and ethanol and air-dried at room temperature.
Cu-Gehalt:Cu content:
52 Gew.-%.52% by weight.
Leitfähigkeit:Conductivity:
2·104 S/cm.2 · 10 4 S / cm.
Zum Vergleich:For comparison:
Leitfähigkeit einer nicht beschichteten Faser: 10-12 S/cm.Conductivity of an uncoated fiber: 10 -12 S / cm.
Beispiel 2Example 2 Herstellung Nickel-beschichteter MelaminharzfasernManufacture of nickel-coated melamine resin fibers

  • (a) Aktivierung der Melaminharzfasern
    Zu einer Lösung von 0,25 mmol Nickel-(II)-chlorid-Hexahydrat, 0,25 mmol Zitronensäure und 200 ml dest. Wasser wurde, nach dem sich ein konstanter pH-Wert von 3,24 eingestellt hatte, 1 g Melaminfasern (Basofil® O, BASF) gegeben. Nach vollständiger Benetzung der Melaminharzfasern wurden 1,47 g (0,4 mmol) einer 1 gew.-%igen Natriumborhydridlösung tropfenweise so zugegeben, daß jeweils nach Schwarzfärbung der Eintropfstelle die Zugabe unterbrochen und danach die Lösung langsam gerührt wurde, bis die Schwarzfärbung verschwunden war. Dieser Vorgang wurde so oft wiederholt, bis die Lösung hellgrau war und einen pH-Wert von 4,7 hatte. Danach wurden die Fasern mit destilliertem Wasser gewaschen.     (a) Activation of the melamine resin fibers
    To a solution of 0.25 mmol nickel (II) chloride hexahydrate, 0.25 mmol citric acid and 200 ml dist. After a constant pH of 3.24 had been set, water was added to 1 g of melamine fibers (Basofil® O, BASF). After the melamine resin fibers had been completely wetted, 1.47 g (0.4 mmol) of a 1% strength by weight sodium borohydride solution were added dropwise in such a way that the addition was interrupted after the dropping point had turned black, and the solution was then slowly stirred until the black color had disappeared . This process was repeated until the solution was light gray and had a pH of 4.7. The fibers were then washed with distilled water.
  • (b) Vernickelung der Melaminharzfasern
    Zu einer Lösung aus 9,853 g (33,5 mmol) Tri-Natriumcitrat-5,5-hydrat, 4,948 g (92,5 mmol) Ammoniumchlorid, 1,087 g (10,26 mmol) Natriumhypophosphit und 60 ml dest. Wasser wurden 4,454 g (18,7 mmol) Nickel-(II)-chlorid-Hexahydrat, gelöst in 40 ml dest. Wasser, gegeben. Danach wurden 9,976 g einer 25 gew.-%igen Ammoniaklösung hinzugefügt. Die Lösung wurde dann auf 96°C erhitzt. Anschließend wurde 1 g der unter (a) erhaltenen Melaminharzfasern in die Lösung gegeben und 90 min bei 96°C gerührt. Dann wurden die vernickelten Fasern zuerst mit dest. Wasser, anschließend mit Ethanol gewaschen und schließlich an der Luft getrocknet. Die grauen, metallisch glänzenden Fasern hatten einen Nickelgehalt von 38 Gew.-%.     (b) Nickel plating of the melamine resin fibers
    To a solution of 9.853 g (33.5 mmol) of tri-sodium citrate-5.5-hydrate, 4.948 g (92.5 mmol) of ammonium chloride, 1.087 g (10.26 mmol) of sodium hypophosphite and 60 ml of dist. Water was 4.454 g (18.7 mmol) of nickel (II) chloride hexahydrate, dissolved in 40 ml of dist. Water. Then 9.976 g of a 25% by weight ammonia solution were added. The solution was then heated to 96 ° C. Then 1 g of the melamine resin fibers obtained under (a) was added to the solution and stirred at 96 ° C. for 90 min. Then the nickel-plated fibers were first distilled. Water, then washed with ethanol and finally air-dried. The gray, shiny metallic fibers had a nickel content of 38% by weight.

Claims (6)

  1. A process for the production of metal-coated melamine/formaldehyde resin fibers by
    Ia activating the fiber surfaces by treating the fibers with an aqueous solution which contains a water-soluble transition metal salt, with the exception of noble metal salts, and a nonnoble metal or metal salt as a reducing agent, or
    Ib activating the fiber surfaces by treating the fibers with an aqueous solution which contains a water-soluble transition metal salt, with the exception of nobel metal salts, a complexing agent and a hydride compound as a reducing agent,
    II if required carrying out a further reducing treatment with reducing agents for converting deposited lower oxidation states into the metallic state and
    III then coating the activated fibers by treating the fibers with an aqueous solution which contains a water-soluble transition metal salt, a complexing agent and a reducing agent.
  2. A process as claimed in claim 1, wherein the water-soluble transition-metal salt used is a nickel salt or a copper salt.
  3. A metal-coated melamine-formaldehyde resin fiber obtainable by a process as claimed in claim 1 or 2.
  4. Use of the metal-coated melamine-formaldehyde resin fibers as claimed in claim 3 for the production of composite materials.
  5. A composite material containing metal-coated melamine-formaldehyde resin fibers as claimed in claim 3, having a fiber content of 1 to 40 % by weight, based on the total weight of the composite material.
  6. Use of a water-soluble copper or nickel salt for activating surfaces of melamine/formaldehyde resin fibers in the production of metal-coated melamine/formaldehyde resin fibers.
EP92112480A 1991-08-02 1992-07-21 Metal-coated melamine-formaldehyde fibers Expired - Lifetime EP0528192B1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
DE4125601A DE4125601A1 (en) 1991-08-02 1991-08-02 METAL-COVERED MELAMINE FORMALDEHYDE RESIN FIBERS
DE4125601 1991-08-02

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EP0528192A1 EP0528192A1 (en) 1993-02-24
EP0528192B1 true EP0528192B1 (en) 1996-11-13

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DE4316607A1 (en) * 1993-05-18 1994-11-24 Wilhelm Endlich Metallised plastic fibre pieces as filler in adhesives, sealants, coating compositions and lubricants
DE4438791C2 (en) * 1994-10-18 1996-09-05 Atotech Deutschland Gmbh Substrate provided with metallized polyimide surfaces
DE19518942C2 (en) * 1995-05-23 1998-12-10 Fraunhofer Ges Forschung Process for the production of metallized polymer particles and polymer material produced by the process and their use
DE19523081A1 (en) * 1995-06-26 1997-01-02 Basf Ag Fiber blend of melamine resin fibers and natural fibers
DE19617634A1 (en) 1996-05-02 1997-11-06 Basf Ag Flame retardant fabric based on melamine resin fibers
US6153167A (en) * 1998-05-12 2000-11-28 American Air Liquide Generation of metal-carbonyl standards for the calibration of spectroscopic systems
US6468672B1 (en) 2000-06-29 2002-10-22 Lacks Enterprises, Inc. Decorative chrome electroplate on plastics
DE10133787A1 (en) * 2001-07-16 2003-02-06 Basf Ag Flame retardant textile fabrics
US6645557B2 (en) * 2001-10-17 2003-11-11 Atotech Deutschland Gmbh Metallization of non-conductive surfaces with silver catalyst and electroless metal compositions
US6875260B2 (en) * 2002-12-10 2005-04-05 Enthone Inc. Copper activator solution and method for semiconductor seed layer enhancement
CN109867829A (en) * 2017-12-04 2019-06-11 洛阳尖端技术研究院 A kind of carbonyl iron dust wave absorbing agent and preparation method thereof

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US3329512A (en) * 1966-04-04 1967-07-04 Shipley Co Chemical deposition of copper and solutions therefor
US3874882A (en) * 1972-02-09 1975-04-01 Shipley Co Catalyst solution for electroless deposition of metal on substrate
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US4803097A (en) * 1987-04-20 1989-02-07 Allied-Signal Inc. Metal plating of plastic materials

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MX9204491A (en) 1993-02-01
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US5560961A (en) 1996-10-01
DE4125601A1 (en) 1993-02-04
ES2093744T3 (en) 1997-01-01
DE59207513D1 (en) 1996-12-19
EP0528192A1 (en) 1993-02-24
JP3016965B2 (en) 2000-03-06

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