EP2561117B1 - Process for coating a surface of a substrate made of nonmetallic material with a metal layer - Google Patents

Description

The present invention relates to a method of coating a surface of a non-metallic material substrate with a metal layer to render it capable of being treated, thanks to the strong adhesion of the coating, by conventional metallization processes such as electroplating .

Materials metallization processes involve depositing a thin layer of metal on the surface of a substrate. The interest of these processes is multiple: visual, decorative, conductive, reinforcement ... It is commonly used for parts used in the aerospace industry, automotive, cosmetics, household appliances, sanitary ware, connectors , microelectronics ...

Many metallization processes for non-metallic substrates have been described in the literature and patents.

Most of these metallization processes use the electroconductive or electrochemical potential properties of metal particles that have been deposited on non-metallic substrates during a so-called activation step. This activation step is also commonly preceded by a step of increasing the specific surface area so that the substrate is sufficiently "rough" to allow good adhesion of the metal particles.

The major disadvantage of these processes is in particular the use of hexavalent chromium during the etching step or modification of the surface roughness of the substrate, a powerful oxidant which makes it possible to obtain a high roughness necessary for gripping the particles. but which is known for its high toxicity.

The step of activating the surface consists in depositing and maintaining on the surface of the non-metallic material metal particles or metal cations which will subsequently be reduced to form metal particles. This step requires the use of colloidal palladium / tin particles which react only on a certain type of polymer and which requires the use of large quantities of palladium.

The article of Nagao T et al. (Galvanotechnik, 2006, 97, 7, 2124-2130 ) for example a synthesis of the techniques used for the metallization of ABS substrates which include steps of cleaning and conditioning of the surfaces, a step of etching with hexavalent chromium solutions, a step depositing colloid Sn-Pd and a step of autocatalytic deposition of metal and more particularly copper. This article also reviews a so-called "Direct Acid Copper Plating" CRP technique that does not include the self-catalytic deposition step of metal, but which requires the addition of palladium in the pickling bath and / or large quantities of Pd / Sn colloid in the catalyst bath.

To limit the use of hexavalent chromium pickling solutions, in the application US 3598630 the stripping step of ABS panels is carried out with a solution of potassium permanganate and phosphoric acid and the step of forming the Sn / Pd colloid is carried out by successive applications of a solution of tin chloride and then of a solution of palladium chloride. In the process described, the self-catalytic metal deposition step is a conventional copper deposition step.

To limit the use of Palladium, alternative solutions have been proposed, for example in the application WO 02/36853 , the conventional method of metallization of an ABS substrate is modified by replacement of the Sn / Pd colloid with an Ag / Sn colloid and after total elimination of Sn ions, the self-catalytic metal deposition step is a deposition step of nickel. After the pickling step by conventional chromic solutions and rinsing treatment of the etched surface with a solution of adsorption enhancing products such as polyelectrolytes in the form of cationic polymers can be carried out.

In addition to the important use of palladium whose cost and rarity are a problem when it is not substituted by silver, in all the processes described above the activation step is a step of adsorption in which a colloidal preparation is used or formed by addition of stannous ions, which must then be completely removed to allow the smooth and uniform development of the metal layer during the electroless metal deposition step.

Alternative methods which do not implement, during the step of activating colloidal solutions, and replacing the adsorption by a chemical bond of metal ions in the form of complexes or chelates have been proposed.

For example, US Patents 4,981,715 and US 4,701,351 describe a method of coating a substrate with a thin layer of a polymer, for example polyacrylic acid, capable of complexing a noble metal compound comprising a step of covering the substrate with a polymer capable of chelating metal ions, followed by a step of contacting the polymer with metal particles. The substrate is then subjected to the auto-catalytic metal deposition step. In the exemplary embodiments, the metal cations used are However, the main drawback of this method is that it entails the need to manage the quality of an additional interface, namely that which is created between the substrate and the polymer layer capable of chelating a metal ion. Solutions are proposed for example for the irradiation treatment which also allows the regioselective attachment of this layer of polymer capable of chelating and thus the possibility of metallizing the substrate selectively.

This solution, if it makes it possible to dispense with the use of the colloids, leads to the formation of an additional layer, the cohesion of which with the substrate or the solidity of the fixing on the substrate will be managed on an industrial scale as well as a step additional in the manufacturing process. In addition, compatibility problems between the constituent material of the substrate and the polymer capable of chelating can also occur.

The present invention makes it possible to simplify the various steps of this method of coating non-metallic materials and to make it more environmentally friendly and less expensive, by developing a simpler coating process that does not use toxic and polluting reagents, without adding a step and an additional layer.

1. a) on dispose d'un substrat en matériau non métallique,
2. b) on soumet au moins une partie d'au moins une surface dudit substrat à un traitement physique ou chimique d'augmentation de la surface spécifique,
3. c) on soumet la surface dudit substrat traitée à l'étape b), à un traitement oxydant,
4. d) on met en contact la surface dudit substrat traitée à l'étape c), avec une solution contenant au moins un ion d'au moins un métal et son contre-ion, ledit métal étant choisi dans le groupe constitué par les métaux des groupes IB et VIII du tableau de la classification périodique des éléments,
5. e) on obtient un substrat comprenant des ions d'au moins un métal fixés chimiquement au matériau non métallique constituant le substrat sur au moins une partie d'au moins une de ses surfaces,
6. f) on soumet lesdits ions d'au moins un métal fixés au matériau non métallique constituant le substrat sur une surface dudit substrat, à un traitement réducteur et on obtient un substrat comprenant des atomes d'au moins un métal fixés au matériau non métallique constituant le substrat sur au moins une partie d'au moins une de ses surfaces,
7. g) on met en contact la surface comprenant des particules d'au moins un métal obtenue à l'étape f) avec une solution contenant des ions d'au moins un métal.
8. h) on obtient sur la surface traitée dudit substrat un revêtement par une couche d'au moins un métal, lesdites étapes étant éventuellement suivies ou précédées de une ou plusieurs étapes de rinçage.

The present invention therefore relates to a method of coating a surface of a substrate of non-metallic material with a metal layer, consisting of the following steps:

1. a) there is a substrate of non-metallic material,
2. b) subjecting at least a part of at least one surface of said substrate to a physical or chemical treatment for increasing the specific surface area,
3. c) subjecting the surface of said substrate treated in step b) to an oxidizing treatment,
4. d) the surface of said substrate treated in step c) is brought into contact with a solution containing at least one ion of at least one metal and its counterion, said metal being chosen from the group consisting of the metals of groups IB and VIII of the table of the periodic table of elements,
5. e) obtaining a substrate comprising ions of at least one metal chemically bonded to the nonmetallic material constituting the substrate on at least a part of at least one of its surfaces,
6. f) subjecting said ions of at least one metal attached to the non-metallic material constituting the substrate to a surface of said substrate to a reducing treatment and obtaining a substrate comprising atoms of at least one metal fixed to the non-metallic material constituting the substrate on at least a part of at least one of its surfaces,
7. g) contacting the surface comprising particles of at least one metal obtained in step f) with a solution containing ions of at least one metal.
8. h) on the treated surface of said substrate is obtained a coating by a layer of at least one metal, said steps optionally being followed or preceded by one or more rinsing steps.

Step g) is a self-catalytic deposition step also called electroless.

Chemically bonded ions and / or atoms are understood to mean atoms or ions bound by chelation and / or complexation by functions or groups, for example carboxylic (-COOH), hydroxyl (-OH), alkoxyl (-OR), carbonyl (-C = O), percarboxylic (-CO-O-OH), nitro (N = O) and amide (-CONH) on the surface of said material.

In step f) the atoms of at least one metal attached to the non-metallic material constituting the substrate are fixed by ligand-metal interactions.

In one embodiment, step d) of activation is performed by contact with a solution containing a single metal ion and its counterion.

In one embodiment, steps b) and c) are performed in a single step b ') and the treatment is an oxidative treatment.

In one embodiment, the metal of step f) and the metal of the ions of step g) are identical.

In one embodiment, steps f) and g) are performed in a single step f ').

During the coating process, the surface of said substrate of non-metallic material must first be prepared in order to obtain a good adhesion of the metal layer on the surface. The surface of the substrate is cleaned of all its contaminants by simultaneously creating a hooking relief for the adhesion of the future coating during step b) of the process.

The surface of the substrate may be treated in whole or in part using masking techniques well known to those skilled in the art such as the use of protective varnishes resistant to oxidation steps.

In one embodiment, step b) is implemented by physical processing.

By physical treatment is meant a treatment to remove the weak cohesion layers and increase the surface roughness.

In one embodiment, the physical treatment is selected from the group of impact treatments.

In one embodiment, steps b) or b ') or c) are carried out by oxidative treatment.

By oxidizing treatment is meant any treatment that makes it possible to prepare the surface by increasing the roughness and therefore the specific surface area for step b) and creating functions capable of chelating and / or complexing metal cations for step c) .

In one embodiment, the oxidizing treatment is selected from the group of chemical oxidizing treatments.

In one embodiment, the oxidizing treatment is chosen from the group of electrochemical oxidizing treatments.

In one embodiment, the oxidizing treatment of step c) is selected from the group of physical oxidative treatments.

According to the present invention, the substrate may be a nanoparticle, a microparticle, a cosmetic stopper, an electronic element, a door handle, an electrical appliance, spectacles, a decorative object, a bodywork element, an element of cabin, airplane wing, a flexible driver or connector.

Non-metallic materials are any material belonging to the family of organic materials, the family of mineral materials and the family of composite materials. Non-limiting examples include wood, paper, cardboard, ceramics, plastics, silicones, textiles and glass.

In one embodiment, the organic material is selected from plastics.

By metal layer is meant a thin layer, from a few nanometers to several hundred microns, a metal and / or a metal oxide deposited on the surface of a substrate.

In one embodiment, the non-metallic material is a polymer selected from the group consisting of natural, artificial, synthetic, thermoplastic, thermosetting, thermostable, elastomeric, one-dimensional and three-dimensional.

In one embodiment, the non-metallic material may further comprise at least one member selected from the group consisting of fillers, plasticizers and additives.

In one embodiment, the fillers are mineral fillers selected from the group consisting of silica, talc, fibers or glass beads.

In one embodiment, the fillers are organic fillers selected from the group consisting of cereal flour and cellulose pulp.

The additives are used to improve a specific property of the non-metallic material such as its color, crosslinking, slipping, resistance to degradation, fire and / or bacterial and / or fungal attacks.

In one embodiment, the polymer is a thermoplastic (co) polymer selected from the group consisting of a polyolefin, a polyester, a polyether, a vinyl polymer, a vinylidene polymer, a styrenic polymer, a (meth) acrylic polymer, a polyamide , a fluoropolymer, a cellulosic polymer, a poly (arylenesulfone), a polysulfide, a poly (arylether) ketone, a polyamide-imide, a poly (ether) imide, a polybenzimidazole, a poly (indene / coumarone), a poly (paraxylylene), alone, in a mixture, in copolymers or in combination.

The polyolefins may be chosen from the group comprising a polyethylene, a polypropylene, an ethylene / propylene copolymer, a polybutylene, a polymethylpentene, an ethylene / vinyl acetate copolymer, an ethylene / vinyl alcohol copolymer or an ethylene / methyl acrylate copolymer, alone. , in a mixture, in copolymers or in combination.

The polyesters may be selected from the group consisting of polyethylene terephthalate, modified or unmodified by glycol, polybutylene terephthalate, polyactide, polycarbonate, alone, in admixture, copolymers or in combination.

The polyethers may be chosen from the group comprising a poly (oxymethylene), a poly (oxyethylene), a poly (oxypropylene), a poly (phenylene ether), alone, in a mixture, in copolymers or in combination.

The vinyl polymers may be selected from the group consisting of optionally chlorinated polyvinyl chloride, polyvinyl alcohol, polyvinyl acetate, polyvinyl acetal, polyvinyl formaldehyde , a polyvinyl fluoride, polyvinyl chloride / vinyl acetate, whether alone, in admixture, in copolymers or in combination.

The vinylidene polymers may be selected from the group consisting of polyvinylidene chloride, polyvinylidene fluoride, alone, as a mixture, copolymer or combination.

The styrenic polymers may be selected from the group consisting of polystyrene, poly (styrene / butadiene), poly (acrylonitrile / butadiene / styrene), poly (acrylonitrile / styrene), poly (acrylonitrile / ethylene / propylene / styrene) , a poly (acrylonitrile / styrene / acrylate), alone, as a mixture, copolymers or in combination.

The (meth) acrylic polymers may be chosen from the group comprising a polyacrylonitrile, a poly (methyl acrylate), a poly (methyl methacrylate), alone, in a mixture, in copolymers or in combination.

The polyamides may be chosen from the group comprising a poly (caprolactam), a poly (hexamethylene adipamide), a poly (lauroamide), a polyether-block-amide, a poly (metaxylylene adipamide) and a poly (metaphenylene isophthalamide), alone. , in a mixture, in copolymers or in combination.

The fluorinated polymers may be chosen from the group comprising a polytetrafluoroethylene, a polychlorotrifluoroethylene, a perfluorinated poly (ethylene / propylene), a polyvinylidene fluoride, alone, in a mixture, in copolymers or in combination.

The cellulosic polymers may be selected from the group consisting of cellulose acetate, cellulose nitrate, methylcellulose, carboxymethylcellulose, ethylmethylcellulose, alone, in admixture, copolymers or in combination.

The poly (arylenesulfone) may be selected from the group consisting of a polysulfone, a polyethersulfone, a polyarylsulfone, alone, as a mixture, copolymers or in combination.

The polysulfides may be poly (phenylene sulfide).

The poly (aryl ether ketones) may be chosen from the group comprising a poly (ether ketone), a poly (ether ether ketone), a poly (ether ketone ketone), alone, as a mixture, by copolymers or in combination.

In one embodiment, the polymer is a thermosetting (co) polymer selected from the group comprising an aminoplast such as urea-formaldehyde, melanin-formaldehyde, melanin-formaldehyde / polyesters, alone, as copolymers, mixed or in combination, a polyurethane, an unsaturated polyester, a polysiloxane, a formophenolic resin, epoxide, allyl or vinylester, an alkyd, a polyurea, a polyisocyanurate, a poly (bismaleimide), a polybenzimidazole, a polydicyclopentadiene, alone, in copolymers, in admixture or combination.

In one embodiment, the (co) polymer is selected from the group consisting of acrylonitrile butadiene styrene (ABS), acrylonitrile butadiene styrene / polycarbonate (ABS / PC), methyl methacrylate acrylonitrile butadiene styrene (MABS), a polyamide (PA) such as nylon, polyamine, polyacrylic acid, polyaniline and polyethylene terephthalate (PET).

In one embodiment, the metal of the metal ion used in step d) is selected from copper, silver, nickel, platinum, palladium or cobalt ions.

In one embodiment, the metal of the metal ion used in step d) is selected from the group consisting of copper and nickel.

In one embodiment, the metal of the metal ion used in step d) is copper.

In one embodiment, the metal of the metal ions used in step g) or f ') is selected from the elements of groups IB and VIII of the Periodic Table.

In one embodiment, the metal of the metal ion used in step g) or f ') is selected from copper, silver, gold, nickel, platinum, palladium, iron or cobalt ions.

In one embodiment, the metal of the metal ion used in step g) or f ') is selected from the group consisting of copper and nickel.

In one embodiment, the metal of the metal ion used in step g) or f ') is copper.

In one embodiment, the metal of the metal ion used in step g) or f ') is nickel.

According to the invention, the group of impact treatments includes sanding, shot blasting, microbilling and abrasive sanding.

The term "chemical oxidizing treatment" is intended to mean a process for oxidizing the surface of the substrate by fixing and / or introducing oxygen-rich groups such as carboxylic (-COOH), hydroxyl (-OH) and alkoxyl (-OR) groups. ), carbonyl (-C = O), percarboxylic acid (-CO-O-OH), nitro (N = O) and amide (-CONH) capable of chemically binding the metal cations, then the reduced metals by chelation and / or complexation .

According to the invention, the chemical oxidizing treatment is chosen from the group comprising Fenton's reagent, alcoholic potash, a strong acid, sodium hydroxide, a strong oxidant, ozone, alone or in combination.

In one embodiment, the strong acid is selected from the group consisting of hydrochloric acid, sulfuric acid, nitric acid, perchloric acid, acetic acid, oxalic acid, phosphorous acid , phosphoric acid, hypophosphorous acid alone or as a mixture.

In one embodiment, the strong oxidant is selected from the group consisting of KMnO ₄ and KClO ₃ , alone or as a mixture.

In one embodiment, the strong oxidant is KMnO ₄ .

The oxidizing treatments are chosen according to the nature of the constituent materials of the substrates, in Table 1 below are illustrated by way of examples, various chemical oxidizing treatments applicable when the substrate is ABS or ABS / PC. <b> Table 1 </ b> oxidizer Acid alone or in combination KMnO ₄ H ₃ PO ₄ H ₃ PO ₂ H ₃ PO ₃ H ₂ SO ₄ C ₂ H ₂ O ₄ H ₂ PO ₄ + C ₂ H ₂ O ₄ H ₃ PO ₂ + C ₂ H ₂ O ₄ H ₃ PO ₄ + H ₂ SO ₄ H ₃ PO ₂ + H ₂ SO ₄ HNO ₃ + HCl HNO ₃ HCl CH ₃ COOH CH ₃ COOH

In Table 2 below are illustrated various oxidizing treatments depending on the nature of the substrate. <b> Table 2 </ b> Types of substrates Nature of oxidative treatments PP KMnO ₄ + H ₃ PO ₄ ABS KMnO ₄ + H ₃ PO ₄ ABS PC KMnO ₄ + H ₃ PO ₄ PA HCl + Isopropanol PPS HNO ₃ + NaOH MABS KMnO ₄ + H ₃ PO ₄ + H ₂ SO ₄ CH ₃ COOH PC H ₂ SO ₄ + HNO ₃ H ₂ SO ₄ KOH

In one embodiment, the solid acid mass ratios are between 5 and 100%.

In one embodiment, they are between 50 and 95%.

In one embodiment, they are between 70 and 90%.

In one embodiment, the duration of the strong acid treatment is between 20 seconds and 5 hours.

In one embodiment, it is between 30 seconds and 3 hours.

In one embodiment, it is between 30 seconds and 20 minutes.

In one embodiment, the duration of the Fenton chemical reaction treatment is between 5 minutes and 5 hours.

In one embodiment, it is between 10 minutes and 3 hours.

In one embodiment, it is between 15 minutes and 2 hours.

In one embodiment, it is of the order of 25 minutes.

In one embodiment, for the treatment with alcoholic potash, the potassium hydroxide is diluted in a solution containing as solvent an alcohol selected from the group comprising methanol, ethanol, and propanol.

In one embodiment, said potassium hydroxide is diluted in a solution containing ethanol as the solvent.

In one embodiment, the concentration of potassium hydroxide in the alcoholic solution is between 0.1M and 10M.

In one embodiment, it is between 0.5M and 5M.

In one embodiment, it is of the order of 3.5M.

In one embodiment, the duration of the alcoholic potash treatment is between 5 minutes and 5 hours.

In one embodiment, it is between 1 minute and 3 hours.

In one embodiment, it is between 5 minutes and 1 hour.

In one embodiment, for treatment with sodium hydroxide, the mass ratios of sodium hydroxide are between 10 and 100%.

In one embodiment, they are between 15 and 70%.

In one embodiment, they are between 20 and 50%.

In one embodiment, for treatment with a strong oxidant, the strong oxidant solution is neutral, acidic or basic.

In one embodiment, the strong oxidant solution is acidic.

In one embodiment, the strong oxidant is selected from the group consisting of KMnO ₄ and KClO ₃ , alone or as a mixture, in hydrochloric acid, in sulfuric acid, in nitric acid and in oxalic acid. , in phosphoric acid, in hydrophosphorous acid or in phosphorous acid.

In one embodiment, the concentration of KMnO ₄ or KClO ₃ is between 10mM and 1M.

In one embodiment, it is between 0.1M and 0.5M.

In one embodiment, it is of the order of 0.2M.

In one embodiment, the acid concentration is between 0.1M and 10M.

In one embodiment, it is between 0.5M and 5M.

In one embodiment, it is of the order of 3.5M.

In one embodiment, the duration of the treatment for a strong oxidant is between 1 minute and 3 hours.

In one embodiment, it is between 5 minutes and 1 hour.

In one embodiment, it is between 6 minutes and 30 minutes.

In one embodiment, it is of the order of 15 minutes.

In one embodiment, chemical oxidative treatment is an electrochemical treatment.

According to the invention, the counter-ion of the at least one metal of step d) is selected from the group consisting of tetrafluoroborate, sulfate, bromide, fluoride, iodide, nitrate, phosphate and chloride ions.

In one embodiment, the solution of step d) containing at least one ion of at least one metal and its counterion is a basic solution.

In one embodiment, the basic solution has a pH greater than 7.

In one embodiment, it has a pH between 9 and 11.

In one embodiment, it has a pH of the order of 10.

In one embodiment, the duration of the treatment of step d) is between 30 seconds and 2 hours.

In one embodiment, it is between 1 minute and 1 hour.

In one embodiment, it is of the order of 15 minutes.

According to the invention, the reducing solution of the reducing treatment in step f) is basic.

In one embodiment, the reducing solution comprises a reducing agent selected from the group consisting of sodium borohydride, dimethylamineborane or hydrazine solutions.

In one embodiment, the reducing agent is a solution of sodium borohydride.

In one embodiment, the sodium borohydride solution has a neutral or basic pH.

In one embodiment, the dimethylamineborane solution has a basic pH.

In one embodiment, the pH is basic, the sodium hydroxide in solution is used as the solvent.

In one embodiment, the concentration of sodium hydroxide is between 10 ^-4 M and 5M.

In one embodiment, it is between 0.05M and 1M.

In one embodiment, it is of the order of 0.1M.

In one embodiment, the concentration of reducing agent in the reducing solution of step f) is between 10 ^-4 M and 5M.

In one embodiment, it is between 0.01M and 1M.

In one embodiment, it is of the order of 0.3M.

In one embodiment, the reduction step is carried out at a temperature between 10 ° C and 90 ° C.

In one embodiment, it is carried out at a temperature of between 30 ° C and 70 ° C.

In one embodiment, it is carried out at a temperature of the order of 50 ° C.

In one embodiment, the duration of the reduction step is between 30 seconds and 1 hour.

In one embodiment, it is between 1 minute and 30 minutes.

In one embodiment, it is between 2 minutes and 20 minutes.

In one embodiment, the solution of step f ') comprises metal ions, a metal ion complexing agent, a reducing agent and a pH regulator.

In one embodiment, said solution of step f ') is an aqueous solution.

In one embodiment, the solution of step f ') is an electroless bath solution containing a metal cation chosen from: Ag ⁺ , Ag ²⁺ , Ag ³⁺ , Au ⁺ , Au ³⁺ , Co ²⁺ , Cu ⁺ , Cu ²⁺ , Fe ²⁺ , Ni ²⁺ , Pd ⁺ and Pt ⁺ .

In one embodiment, the solution of step f ') is an electroless bath solution containing a metal cation chosen from: Co ²⁺ , Cu ⁺ , Cu ²⁺ , Ni ²⁺ , and Pt ⁺ .

In one embodiment, the solution of step g) containing ions of at least one metal is an aqueous solution.

In one embodiment, said solution of step g) is an electroless bath solution containing a metal cation chosen from: Ag ⁺ , Ag ²⁺ , Ag ³⁺ , Au ⁺ , Au ³⁺ , Co ²⁺ , Cu ⁺ , Cu ²⁺ , Fe ²⁺ , Ni ²⁺ , Pd ⁺ and Pt ⁺ .

In one embodiment, the solution of step g) is an electroless bath solution containing a metal cation chosen from: Co ²⁺ , Cu ⁺ , Cu ²⁺ , Ni ²⁺ , and Pt ⁺ .

In one embodiment, the solution of step g) is an electroless bath solution containing a metal cation selected from: Cu ²⁺ and Ni ²⁺ .

In one embodiment, the duration of step g) is between 1 minute and 1 hour.

According to the invention, before and between each step of the process, the surface of the substrate and / or the substrate is / are subjected to one or more rinses with at least one rinsing solution.

In one embodiment, the rinsing solutions are the same or different.

In one embodiment, the rinse solution is selected from the group consisting of water, distilled water, deionized water, or an aqueous solution containing a detergent.

In one embodiment, the detergent contained in an aqueous solution is chosen from the group comprising TDF4 and sodium hydroxide.

In one embodiment, the concentration of sodium hydroxide is between 0.01M and 1M.

In one embodiment, the rinse solution is agitated upon contact with the surface of the substrate and / or the substrate.

In one embodiment, the stirring is carried out using an agitator, a recirculation pump, a bubbling air or a gas, an ultrasonic bath or a homogenizer.

In one embodiment, the duration of each rinsing step is between 1 second to 30 minutes.

In one embodiment, it is between 5 seconds to 20 minutes.

The contacting of the surface of the substrate and / or the substrate with the solutions of the different steps can be done by immersion in a bath or by spraying and / or showering.

When this contacting is done by immersion in a bath, the homogenization of said bath is carried out using an agitator, a recirculation pump, a bubbling air or a gas, an ultrasonic bath or a homogenizer.

The invention also relates to the substrate obtained according to the method of the invention for which the surface of said substrate of non-metallic material is coated with a metal layer.

The invention relates to a substrate of non-metallic material, at least one surface of which is coated with a metal activation layer consisting of metal atoms bound by metal-ligand interaction directly to the constituent material of the substrate by carboxylic groups (- COOH), hydroxyl (-OH), alkoxyl (-OR), carbonyl (-C = O), percarbonic (-CO-O-OH), nitro (N = O) or amide (-CONH), said activation layer being coated with a layer of the same or different metal deposited by self-catalytic deposition.

In one embodiment, the invention relates to a substrate made of ABS, the surface of which is coated with an activation layer made of copper, the atoms of which are bonded by metal-ligand interaction to the ABS constituting the substrate, said activation layer being covered with a layer of copper deposited by autocatalytic deposition.

In one embodiment, the invention relates to a substrate made of ABS, the surface of which is coated with an activation layer made of nickel, the atoms of which are bonded to a metal-ligand interaction with the constituent ABS of the substrate, said layer activation being coated with a copper layer deposited by autocatalytic deposition.

In one embodiment, the invention relates to a substrate made of ABS / PC, the surface of which is coated with an activation layer made of copper, the atoms of which are bonded metal-ligand interaction with the ABS / PC constituting the substrate, said activation layer being covered with a layer of copper deposited by autocatalytic deposition

In one embodiment, the invention relates to a substrate made of ABS / PC, the surface of which is coated with an activation layer made of nickel, the atoms of which are bonded by metal-ligand interaction to the constituent ABS / PC. of the substrate, said activation layer being covered with a layer of copper deposited by autocatalytic deposition

In one embodiment, the invention relates to a PA substrate, the surface of which is coated with an activation layer made of copper, the atoms of which are bonded by metal-ligand interaction to the PA constituting the substrate, said layer of activation being covered with a layer of copper deposited by autocatalytic deposition

In one embodiment, the invention relates to a PA substrate whose surface is coated with an activation layer made of nickel, the atoms of which are bonded to a metal-ligand interaction with the PA constituting the substrate, said activation layer being covered with a layer of copper deposited by autocatalytic deposition

In one embodiment, the invention relates to a substrate made of PC, the surface of which is coated with an activation layer made of copper, the atoms of which are bonded by metal-ligand interaction to the constituent PC of the substrate, said layer of activation being covered with a layer of copper deposited by autocatalytic deposition

In one embodiment, the invention relates to a substrate made of PC, the surface of which is coated with an activation layer made of nickel, the atoms of which are bonded by metal-ligand interaction to the constituent PC of the substrate, said layer of activation being covered with a layer of copper deposited by autocatalytic deposition

In one embodiment, the invention relates to a substrate made of MABS, the surface of which is coated with an activation layer made of copper whose atoms are bonded by metal-ligand interaction to the MABS constituting the substrate, said layer of activation being covered with a layer of copper deposited by autocatalytic deposition

In one embodiment, the invention relates to a substrate consisting of MABS, the surface of which is coated with an activation layer consisting of nickel, the atoms of which are bonded by metal-ligand interaction to the MABS constituting the substrate, said layer of activation being covered with a layer of copper deposited by autocatalytic deposition

In one embodiment, the invention relates to a substrate made of PP, the surface of which is coated with an activation layer made of copper whose atoms are bonded by metal-ligand interaction to the constituent PP of the substrate, said layer of activation being covered with a layer of copper deposited by autocatalytic deposition

In one embodiment, the invention relates to a substrate consisting of PP, the surface of which is coated with an activation layer consisting of nickel, the atoms of which are bonded by metal-ligand interaction to the constituent PP of the substrate, said layer of activation being covered with a layer of copper or deposited by autocatalytic deposit

In one embodiment, the invention relates to a substrate consisting of PPS, the surface of which is coated with an activation layer made of copper, the atoms of which are bonded by metal-ligand interaction with the PPS constituting the substrate, said layer of activation being covered with a layer of copper or deposited by autocatalytic deposit

In one embodiment, the invention relates to a substrate consisting of PPS, the surface of which is coated with an activation layer consisting of nickel, the atoms of which are bonded by metal-ligand interaction to the constituent PPS of the substrate, said layer of activation being covered with a layer of copper deposited by autocatalytic deposition

In one embodiment, the invention relates to a substrate made of ABS, the surface of which is coated with an activation layer made of copper, the atoms of which are bonded by metal-ligand interaction to the ABS constituting the substrate, said activation layer being coated with a nickel layer deposited by autocatalytic deposition.

In one embodiment, the invention relates to a substrate made of ABS, the surface of which is coated with an activation layer made of nickel, the atoms of which are bonded by metal-ligand interaction to the ABS constituting the substrate, said activation layer being coated with a nickel layer deposited by autocatalytic deposition.

In one embodiment, the invention relates to a substrate made of ABS / PC, the surface of which is coated with an activation layer made of copper, the atoms of which are bonded by metal-ligand interaction to the constituent ABS / PC. of the substrate, said activation layer being covered with a layer of nickel deposited by autocatalytic deposition

In one embodiment, the invention relates to a substrate made of ABS / PC, the surface of which is coated with an activation layer made of nickel, the atoms of which are bonded by metal-ligand interaction to the constituent ABS / PC. of the substrate, said activation layer being covered with a layer of nickel deposited by autocatalytic deposition

In one embodiment, the invention relates to a PA substrate, the surface of which is coated with an activation layer made of copper, the atoms of which are bonded by metal-ligand interaction to the PA constituting the substrate, said layer of activation being coated with a nickel layer deposited by autocatalytic deposit

In one embodiment, the invention relates to a PA substrate whose surface is coated with an activation layer made of nickel, the atoms of which are bonded by metal-ligand interaction to the constituent PA of the substrate, said layer of activation being coated with a nickel layer deposited by autocatalytic deposit

In one embodiment, the invention relates to a substrate made of PC, the surface of which is coated with an activation layer made of copper, the atoms of which are bonded by metal-ligand interaction to the constituent PC of the substrate, said layer of activation being coated with a nickel layer deposited by autocatalytic deposit

In one embodiment, the invention relates to a substrate made of PC, the surface of which is coated with an activation layer made of nickel, the atoms of which are bonded by metal-ligand interaction to the constituent PC of the substrate, said layer of activation being coated with a nickel layer deposited by autocatalytic deposit

In one embodiment, the invention relates to a substrate made of MABS, the surface of which is coated with an activation layer made of copper whose atoms are bonded by metal-ligand interaction to the MABS constituting the substrate, said layer of activation being coated with a nickel layer deposited by autocatalytic deposit

In one embodiment, the invention relates to a substrate consisting of MABS, the surface of which is coated with an activation layer consisting of nickel, the atoms of which are bonded by metal-ligand interaction to the MABS constituting the substrate, said layer of activation being coated with a nickel layer deposited by autocatalytic deposit

In one embodiment, the invention relates to a substrate made of PP, the surface of which is coated with an activation layer made of copper whose atoms are bonded by metal-ligand interaction to the constituent PP of the substrate, said layer of activation being coated with a nickel layer deposited by autocatalytic deposit

In one embodiment, the invention relates to a substrate made of PP, the surface of which is coated with an activation layer consisting of nickel, the atoms of which are bonded by metal-ligand interaction to the constituent PP of the substrate, said layer of activation being coated with a nickel layer deposited by autocatalytic deposit

In one embodiment, the invention relates to a substrate consisting of PPS, the surface of which is coated with an activation layer made of copper, the atoms of which are bonded by metal-ligand interaction with the PPS constituting the substrate, said layer of activation being coated with a nickel layer deposited by autocatalytic deposit

In one embodiment, the invention relates to a substrate consisting of PPS, the surface of which is coated with an activation layer consisting of nickel, the atoms of which are bonded by metal-ligand interaction to the constituent PPS of the substrate, said layer of activation being coated with a nickel layer deposited by autocatalytic deposit

The invention also relates to a method according to the invention further comprising a metallization step.

In one embodiment, the metallization treatment is an electroplating treatment.

The invention and its modes of implementation are illustrated in the following examples.

Example 1 I. Coating with a copper layer of acrylonitrile butadiene styrene (ABS) and acrylonitrile butadiene styrene / polycarbonate (ABS / PC) plates.

This method of coating with a copper layer a substrate of non-metallic material is carried out in 4 steps (chemical oxidizing treatment with nitric acid / chelation and / or complexation / reduction / bath Electroless).

I.1. Chemical oxidizing treatment with nitric acid

Pure nitric acid is brought to 50 ° C. In this solution, the acrylonitrile butadiene styrene (ABS) and acrylonitrile butadiene styrene / polycarbonate (ABS / PC) plates were immersed for 8 minutes. The plates are then rinsed twice in a water bath (1 liter).

I.2. chelation and / or complexation of copper ions

Copper sulphate (23.7 g) is solubilized in a solution of water (1000 ml) and ammonia (30 ml). In this bath are immersed parts that have undergone the chemical oxidizing treatment of step 1.1 for 15 minutes. The ABS parts are then rinsed in 0.2 M sodium hydroxide solution.

I.3 Reducing treatment of copper ions

NaBH ₄ sodium borohydride (0.316 g, 0.8 X 10 -2 mol) is dissolved in 25 ml of a 0.1 M sodium hydroxide solution (NaOH). This solution is heated to 80 ° C. using a bain-marie and the samples are immersed in it. After 12 minutes, the samples were rinsed with MilliQ water before being dried.

I.4. Copper Electroless Bath (Mac-Dermid M Copper® Bath)

A solution is prepared containing 100 ml of the solution M Copper® 85 B. Then, 40 ml of the solution M Copper® 85 A, then 30 ml of the solution M Copper® 85 D, then 2 ml of the solution M Copper® 85 g and finally 5 ml of formaldehyde 37% are added. The level of the solution is completed to reach 1 liter of solution. The bath is heated to 60 ° C. with mechanical stirring. The ABS plates are then introduced.

The pieces will be covered with the chemical copper metal film after 3 minutes of immersion.

The copper layer is visible to the naked eye.

I.5. Copper Electroless Bath

In an alternative embodiment, the Electroless bath is a prepared solution containing: 40 ml of PegCopper 100 solution, 100 ml of PegCopper 200 solution, 30 ml of PegCopper 400 and 2 ml of PegCopper 500 (products marketed by PEGASTECH) ). 3.5 ml of PegCopper 600 are then added. The level is completed to reach 1 liter with water and the mixture is brought to 50 ° C. under bubbling. The parts to be treated are then introduced.

The pieces will be covered with the chemical copper metal film after 3 minutes of immersion.

The copper layer is visible to the naked eye.

Example 2 II. Coating with a copper layer of a polyamide substrate.

The coating process is carried out with a substrate made of Minlon ^® polyamide.

II.1. Chemical oxidizing treatment with hydrochloric acid is isopropanol

In an aqueous solution containing water 130 mL, hydrochloric acid (37M), 28 mL and isopropanol 55 mL, the polyamide substrate was immersed at 28 ° C for 17 minutes. The substrate is then rinsed with water.

II.2. Chelation and / or complexation of copper ions

According to a method similar to that described in Example 1, step I.2, copper ions are chelated on the surface of the substrate.

II.3 Reducing treatment of copper ions

According to the procedure described in I.3, the chelated copper ions are reduced on the surface of the substrate

II.4 Copper Electroless Bath

according to a method similar to that described in Example 1, step I.4. or I.5., the polyamide substrate is covered with a chemical copper metal film.

The copper layer is visible to the naked eye.

Example 3 III. Coating with a copper layer of a polycarbonate substrate.

The coating process is carried out with a Lexan® polycarbonate substrate.

III.1. Chemical oxidizing treatment with strong acids

The polycarbonate substrate is immersed in a solution containing a mixture of strong acids (34% nitric acid and 66% sulfuric acid) at 25 ° C. for 5 minutes and then in a concentrated sulfuric acid bath at 25 ° C. for 3 minutes. . The whole is neutralized in a 5N potassium hydroxide solution at 65 ° C. for 5 minutes. The polycarbonate substrate is then rinsed with water.

III.2. Chelation and / or complexation of copper ions

According to a method similar to that described in Example 1, step 1.2, copper ions are chelated on the surface of the substrate.

III.3 Reducing treatment of copper ions

According to the procedure described in I.3, the copper ions are chelated reduced on the surface of the substrate

III.4 Copper Electroless Bath

According to a method similar to that described in Example 1, step I.4. or I.5., the polycarbonate substrate is covered with a chemical copper metal film.

The copper layer is visible to the naked eye.

Example 4

Adhesion tests according to the NF ISO 2409 / NF T30-038 standard and corrosion tests according to DIN ISO 9227 were carried out on the substrates obtained in Examples 1 to 3, and the performances are in accordance with the requirements of these tests. and comparable to performanes obtained with substrates obtained according to the methods of the prior art.

Claims (13)

1. A process for coating a surface of a substrate made of nonmetallic material with a metal layer, characterized in that it comprises the following steps:

   a. a substrate made of nonmetallic material is provided;

   b. at least part of at least one surface of said substrate is subjected to a physical or chemical treatment for increasing the specific surface area thereof;

   c. that surface of said substrate which was treated in step b) is subjected to an oxidizing treatment;

   d. that surface of said substrate which was treated in step c) is brought into contact with a solution containing at least one ion of at least one metal and its counterion, said metal being chosen from the group constituted of the metals of groups IB and VIII of the Periodic Table of the Elements;

   e. a substrate comprising ions of at least one metal that are chemically attached to the nonmetallic material constituting the substrate on at least one part of at least one of its surfaces is obtained;

   f. said ions of at least one metal that are chemically attached to the nonmetallic material constituting the substrate on a surface of said substrate are subjected to a reducing treatment and a substrate comprising atoms of at least one metal that are chemically attached to the nonmetallic material constituting the substrate on at least one part of at least one of its surfaces is obtained;

   g. that surface comprising particles of at least one metal which was obtained in step f) is brought into contact with a solution containing ions of at least one metal;

   h. a coating formed by a layer of at least one metal is obtained on the treated surface of said substrate,

   said steps being optionally followed or preceded by one or more rinsing steps.
2. The process as claimed in claim 1, characterized in that steps b) and c) are carried out as a single step b') and the treatment is an oxidizing treatment.
3. The process as claimed in claim 1, characterized in that the metal of step f) and the metal of the ions of step g) are identical.
4. The process as claimed in anyone of the preceding claims, characterized in that steps f) and g) are carried out as a single step f').
5. The process as claimed in anyone of the preceding claims, characterized in that step b) is implemented by a physical treatment, preferably chosen from the group of impact treatments.
6. The process as claimed in anyone of claims 1 to 4, characterized in that step b) or b') or c) is implemented by an oxidizing treatment.
7. The process as claimed in anyone of claims 1 to 6, characterized in that the oxidizing treatment is chosen from the group of chemical oxidizing treatments, preferably the chemical oxidizing treatment is an electrochemical treatment.
8. The process as claimed in any one of the preceding claims, characterized in that the metal of the metal ion used in step d) is chosen from copper, silver, nickel, platinum, palladium and cobalt ions, preferably from copper and nickel ions.
9. The process as claimed in anyone of the preceding claims, characterized in that the chemical oxidizing treatment is chosen from the group constituted of Fenton's reagent, alcoholic potassium hydroxide, a strong acid, preferably chosen from the group constituted of hydrochloric acid, sulfuric acid, nitric acid, perchloric acid, phosphorous acid, phosphoric acid, hypophosphorous acid, oxalic acid and acetic acid, by themselves or as a mixture, sodium hydroxide, a strong oxidizing agent preferably chosen from the group constituted of KMnO₄ and KClO₃, by themselves or as a mixture and ozone, by themselves or in combinations.
10. The process as claimed in claim 1, characterized in that the reducing solution comprises a reducing agent chosen from the group constituted of sodium borohydride, dimethylamine borane and hydrazine solutions.
11. The process as claimed in claim 1, characterized in that the solution of step f') comprises ions of the metal, a complexing agent that complexes the ions of the metal, a reducing agent and a pH regulator.
12. The process as claimed in claim 1, characterized in that, prior to and between each step of the process, the surface of the substrate and/or the substrate are/is rinsed one or more times with at least one rinsing solution, preferably the rinsing solution is stirred during contacting with the surface of the substrate and/or the substrate.
13. The process as claimed in anyone of claims 1 to 12, which further comprises a metallization step, preferably the metallization step is an electroplating treatment step.