Abstract: A method of regenerating an etch solution comprising a metastable complex of manganese(III) ions in a strong acid is described in which at least a portion of the manganese(III) ions in the metastable complex have been destabilized, causing them to disproportionate into manganese dioxide and manganese(II) ions. The method includes the steps of i) adding an effective amount of a reducing agent to the solution; ii) allowing the reducing agent to react with the solution to cause manganese dioxide to dissolve; and (iii) applying an electrical current to regenerate manganese(III) ions in the solution.

Abstract: A method of regenerating an etch solution comprising a metastable complex of manganese(III) ions in a strong acid is described in which at least a portion of the manganese(III) ions in the metastable complex have been destabilized, causing them to disproportionate into manganese dioxide and manganese(II) ions. The method includes the steps of i) adding an effective amount of a reducing agent to the solution; ii) allowing the reducing agent to react with the solution to cause manganese dioxide to dissolve; and (iii) applying an electrical current to regenerate manganese(III) ions in the solution.

Abstract: A method of treating a substrate, wherein the substrate comprises a layer deposited from a trivalent chromium electrolyte, is described. The method includes the steps of providing an anode and the chromium(III) plated substrate as a cathode in an electrolyte comprising (i) a trivalent chromium salt; and (ii) a complexant; and passing an electrical current between the anode and the cathode to passivate the chromium(III) plated substrate. The substrate may be first plated with a plated nickel layer so that the chromium(III) plated layer is deposited over the nickel plated layer.

Abstract: The invention consists of a chromium electroplating solution comprising a chromium electroplating solution comprising: (1) a water soluble trivalent chromium salt; (2) at least one complexant for trivalent chromium ions; (3) a source of hydrogen ions sufficient to create a pH of from 2.8-4.2; (4) a pH buffering compound; and (5) a sulfur-containing organic compound. The chromium electroplating solution is usable in a method for producing an adherent metallic coating on a decorative article, such coating having enhanced resistance to corrosion in environments containing calcium chloride.

Abstract: A method of coating an electroplating rack used for supporting non-conductive substrates during a plating process. The method comprises the steps of contacting at least a portion of the electroplating rack with a plastisol composition, the plastisol composition having dispersed therein an effective amount of an additive; and heating the electroplating rack with the plastisol composition thereon to a suitable temperature and for a sufficient time to cure the plastisol and form a solid insulating coating on the electroplating rack. The coated electroplating rack may then be used for mounting non-conductive substrates for subsequent metallization steps.

Abstract: The invention consists of a chromium electroplating solution comprising a chromium electroplating solution comprising: (1) a water soluble trivalent chromium salt; (2) at least one complexant for trivalent chromium ions; (3) a source of hydrogen ions sufficient to create a pH of from 2.8-4.2; (4) a pH buffering compound; and (5) a sulfur-containing organic compound. The chromium electroplating solution is usable in a method for producing an adherent metallic coating on a decorative article, such coating having enhanced resistance to corrosion in environments containing calcium chloride.

Abstract: A method of maintaining a concentration of sulfuric acid in an electrolyte comprising manganese(III) ions in a solution of sulfuric acid. The method includes the steps of a) removing a portion of the electrolyte from the electrolytic cell to an annex tank; b) treating the removed portion of the electrolyte in the annex tank to remove moisture from the portion of the electrolyte; and c) returning the treated portion of the electrolyte to the electrolytic cell. The removed portion of the electrolyte is treated by passing a dry gas over the surface of the electrolyte in the annex tank to absorb moisture from the electrolyte and restore the concentration of sulfuric acid in the electrolyte.

Abstract: A method of preparing a plastic substrate to accept metal plating thereon is described. The method includes the steps of pretreating the plastic substrate by contacting the plastic substrate with an aqueous electrolyte comprising an organic salt to raise the surface energy of the plastic substrate. Thereafter, the plastic substrate can be etched and metal plated.

Abstract: An aqueous acidic trivalent chromium electrolyte comprising trivalent chromium ions and a complexing agent for maintaining the trivalent chromium ions in solution is provided in which the aqueous electrolyte comprises additives capable of producing a coating on a substrate having a desired dark hue. The additives typically comprise a dispersion of colloidal silica and an additional additive selected from thiocyanate ions and/or iron ions. The electrolyte is used in a method of producing the desired dark-hued decorative chromium coating on a substrate by electrodeposition.

Abstract: A method of coating an electroplating rack used for supporting non-conductive substrates during a plating process.

Abstract: A method of treating a substrate, wherein the substrate comprises a layer deposited from a trivalent chromium electrolyte, is described. The method includes the steps of providing an anode and the chromium(III) plated substrate as a cathode in an electrolyte comprising (i) a trivalent chromium salt; and (ii) a complexant; and passing an electrical current between the anode and the cathode to passivate the chromium(III) plated substrate. The substrate may be first plated with a plated nickel layer so that the chromium(III) plated layer is deposited over the nickel plated layer.

Abstract: An electroplating rack for supporting non-conductive substrates during an electrodeposition process is described. The electroplating rack is coated with a non-conductive material, such as a PVC plastisol. The electroplating rack is treated with a non-aqueous solution comprising a metallization inhibitor prior to the electrodeposition process to inhibit rack plate up when using etchants that do not contain chromic acid.

Abstract: A method of regenerating an etch solution comprising a metastable complex of manganese(III) ions in a strong acid is described in which at least a portion of the manganese(III) ions in the metastable complex have been destabilized, causing them to disproportionate into manganese dioxide and manganese(II) ions. The method includes the steps of i) adding an effective amount of a reducing agent to the solution; ii) allowing the reducing agent to react with the solution to cause manganese dioxide to dissolve; and (iii) applying an electrical current to regenerate manganese(III) ions in the solution.

Abstract: A process for plating metal on plastic substrates, particularly ABS substrates, without the use of chrome containing etchants is disclosed. The process involves (i) etching the plastic substrate in an acidic solution of nitrate ions, and preferably silver ions, (ii) conditioning the substrate in an aqueous solution containing an amine or ammonia, (iii) activating the substrate, preferably with a palladium activator, and (iv) plating the substrate with an electroless plating solution. The process allows for complete adherent electroless plating of plastic substrates, particularly ABS substrates, without the use of chromic etchants.

Abstract: A process for plating metal on plastic substrates, particularly ABS substrates, without the use of chrome containing etchants is disclosed. The process involves (i) etching the plastic substrate in an acidic solution of nitrate ions, and preferably silver ions, (ii) conditioning the substrate in an aqueous solution containing an amine or ammonia, (iii) activating the substrate, preferably with a palladium activator, and (iv) plating the substrate with an electroless plating solution. The process allows for complete adherent electroless plating of plastic substrates, particularly ABS substrates, without the use of chromic etchants.

Abstract: An aqueous acidic trivalent chromium electrolyte comprising trivalent chromium ions and a complexing agent for maintaining the trivalent chromium ions in solution is provided in which the aqueous electrolyte comprises additives capable of producing a coating on a substrate having a desired dark hue. The additives typically comprise a dispersion of colloidal silica and an additional additive selected from thiocyanate ions and/or iron ions. The electrolyte is used in a method of producing the desired dark-hued decorative chromium coating on a substrate by electrodeposition.

Abstract: An aqueous acidic trivalent chromium electrolyte comprising trivalent chromium ions and a complexing agent for maintaining the trivalent chromium ions in solution is provided in which the aqueous electrolyte comprises additives capable of producing a coating on a substrate having a desired dark hue. The additives typically comprise a dispersion of colloidal silica and an additional additive selected from thiocyanate ions and/or iron ions. The electrolyte is used in a method of producing the desired dark-hued decorative chromium coating on a substrate by electrodeposition.

Abstract: An aqueous acidic trivalent chromium electrolyte comprising trivalent chromium ions and a complexing agent for maintaining the trivalent chromium ions in solution is provided in which the aqueous electrolyte comprises additives capable of producing a coating on a substrate having a desired dark hue. The additives typically comprise a dispersion of colloidal silica and an additional additive selected from thiocyanate ions and/or iron ions. The electrolyte is used in a method of producing the desired dark-hued decorative chromium coating on a substrate by electrodeposition.

Abstract: The invention consists of a chromium electroplating solution comprising a chromium electroplating solution comprising: (1) a water soluble trivalent chromium salt; (2) at least one complexant for trivalent chromium ions; (3) a source of hydrogen ions sufficient to create a pH of from 2.8-4.2; (4) a pH buffering compound; and (5) a sulfur-containing organic compound. The chromium electroplating solution is usable in a method for producing an adherent metallic coating on a decorative article, such coating having enhanced resistance to corrosion in environments containing calcium chloride.

Abstract: The proposed invention comprises a process for plating upon zinc die cast articles without the use of cyanide in the plating solution The process proposes the plating of the zinc die cast articles with a zinc alloy layer first, followed by plating with copper, nickel, chromium, tin or brass. The preferred zinc alloy initial coating is zinc-nickel.