US20030159762A1 - Process for providing a tortoise-shell chromatic effect to metallic substrates - Google Patents

Process for providing a tortoise-shell chromatic effect to metallic substrates Download PDF

Info

Publication number
US20030159762A1
US20030159762A1 US10/359,667 US35966703A US2003159762A1 US 20030159762 A1 US20030159762 A1 US 20030159762A1 US 35966703 A US35966703 A US 35966703A US 2003159762 A1 US2003159762 A1 US 2003159762A1
Authority
US
United States
Prior art keywords
process according
substrate
tortoise
chromatic effect
buffering
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Abandoned
Application number
US10/359,667
Inventor
Ugo Beretta
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Beretta SpA
Original Assignee
Individual
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Individual filed Critical Individual
Assigned to FABBRICA D'ARMI PIETRO BERETTA S.P.A. reassignment FABBRICA D'ARMI PIETRO BERETTA S.P.A. ASSIGNMENT OF ASSIGNORS INTEREST (SEE DOCUMENT FOR DETAILS). Assignors: BERETTA, UGO GUSSALLI
Publication of US20030159762A1 publication Critical patent/US20030159762A1/en
Abandoned legal-status Critical Current

Links

Classifications

    • C—CHEMISTRY; METALLURGY
    • C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
    • C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
    • C23C28/00—Coating for obtaining at least two superposed coatings either by methods not provided for in a single one of groups C23C2/00 - C23C26/00 or by combinations of methods provided for in subclasses C23C and C25C or C25D
    • C23C28/30—Coatings combining at least one metallic layer and at least one inorganic non-metallic layer
    • C23C28/32—Coatings combining at least one metallic layer and at least one inorganic non-metallic layer including at least one pure metallic layer
    • C23C28/322—Coatings combining at least one metallic layer and at least one inorganic non-metallic layer including at least one pure metallic layer only coatings of metal elements only
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B44—DECORATIVE ARTS
    • B44F—SPECIAL DESIGNS OR PICTURES
    • B44F1/00—Designs or pictures characterised by special or unusual light effects
    • B44F1/08—Designs or pictures characterised by special or unusual light effects characterised by colour effects
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B44—DECORATIVE ARTS
    • B44F—SPECIAL DESIGNS OR PICTURES
    • B44F9/00—Designs imitating natural patterns
    • C—CHEMISTRY; METALLURGY
    • C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
    • C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
    • C23C22/00—Chemical surface treatment of metallic material by reaction of the surface with a reactive liquid, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals
    • C23C22/05—Chemical surface treatment of metallic material by reaction of the surface with a reactive liquid, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals using aqueous solutions
    • C23C22/06—Chemical surface treatment of metallic material by reaction of the surface with a reactive liquid, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals using aqueous solutions using aqueous acidic solutions with pH less than 6
    • C23C22/48—Chemical surface treatment of metallic material by reaction of the surface with a reactive liquid, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals using aqueous solutions using aqueous acidic solutions with pH less than 6 not containing phosphates, hexavalent chromium compounds, fluorides or complex fluorides, molybdates, tungstates, vanadates or oxalates
    • C23C22/50—Treatment of iron or alloys based thereon
    • C—CHEMISTRY; METALLURGY
    • C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
    • C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
    • C23C22/00—Chemical surface treatment of metallic material by reaction of the surface with a reactive liquid, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals
    • C23C22/05—Chemical surface treatment of metallic material by reaction of the surface with a reactive liquid, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals using aqueous solutions
    • C23C22/06—Chemical surface treatment of metallic material by reaction of the surface with a reactive liquid, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals using aqueous solutions using aqueous acidic solutions with pH less than 6
    • C23C22/48—Chemical surface treatment of metallic material by reaction of the surface with a reactive liquid, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals using aqueous solutions using aqueous acidic solutions with pH less than 6 not containing phosphates, hexavalent chromium compounds, fluorides or complex fluorides, molybdates, tungstates, vanadates or oxalates
    • C23C22/52—Treatment of copper or alloys based thereon
    • C—CHEMISTRY; METALLURGY
    • C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
    • C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
    • C23C22/00—Chemical surface treatment of metallic material by reaction of the surface with a reactive liquid, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals
    • C23C22/05—Chemical surface treatment of metallic material by reaction of the surface with a reactive liquid, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals using aqueous solutions
    • C23C22/06—Chemical surface treatment of metallic material by reaction of the surface with a reactive liquid, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals using aqueous solutions using aqueous acidic solutions with pH less than 6
    • C23C22/48—Chemical surface treatment of metallic material by reaction of the surface with a reactive liquid, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals using aqueous solutions using aqueous acidic solutions with pH less than 6 not containing phosphates, hexavalent chromium compounds, fluorides or complex fluorides, molybdates, tungstates, vanadates or oxalates
    • C23C22/58—Treatment of other metallic material
    • C—CHEMISTRY; METALLURGY
    • C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
    • C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
    • C23C28/00—Coating for obtaining at least two superposed coatings either by methods not provided for in a single one of groups C23C2/00 - C23C26/00 or by combinations of methods provided for in subclasses C23C and C25C or C25D
    • C23C28/30—Coatings combining at least one metallic layer and at least one inorganic non-metallic layer
    • C23C28/32—Coatings combining at least one metallic layer and at least one inorganic non-metallic layer including at least one pure metallic layer
    • C23C28/321—Coatings combining at least one metallic layer and at least one inorganic non-metallic layer including at least one pure metallic layer with at least one metal alloy layer
    • C—CHEMISTRY; METALLURGY
    • C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
    • C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
    • C23C28/00—Coating for obtaining at least two superposed coatings either by methods not provided for in a single one of groups C23C2/00 - C23C26/00 or by combinations of methods provided for in subclasses C23C and C25C or C25D
    • C23C28/30—Coatings combining at least one metallic layer and at least one inorganic non-metallic layer
    • C23C28/34—Coatings combining at least one metallic layer and at least one inorganic non-metallic layer including at least one inorganic non-metallic material layer, e.g. metal carbide, nitride, boride, silicide layer and their mixtures, enamels, phosphates and sulphates
    • C23C28/345—Coatings combining at least one metallic layer and at least one inorganic non-metallic layer including at least one inorganic non-metallic material layer, e.g. metal carbide, nitride, boride, silicide layer and their mixtures, enamels, phosphates and sulphates with at least one oxide layer
    • C—CHEMISTRY; METALLURGY
    • C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
    • C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
    • C23C28/00—Coating for obtaining at least two superposed coatings either by methods not provided for in a single one of groups C23C2/00 - C23C26/00 or by combinations of methods provided for in subclasses C23C and C25C or C25D
    • C23C28/30—Coatings combining at least one metallic layer and at least one inorganic non-metallic layer
    • C23C28/34—Coatings combining at least one metallic layer and at least one inorganic non-metallic layer including at least one inorganic non-metallic material layer, e.g. metal carbide, nitride, boride, silicide layer and their mixtures, enamels, phosphates and sulphates
    • C23C28/345—Coatings combining at least one metallic layer and at least one inorganic non-metallic layer including at least one inorganic non-metallic material layer, e.g. metal carbide, nitride, boride, silicide layer and their mixtures, enamels, phosphates and sulphates with at least one oxide layer
    • C23C28/3455—Coatings combining at least one metallic layer and at least one inorganic non-metallic layer including at least one inorganic non-metallic material layer, e.g. metal carbide, nitride, boride, silicide layer and their mixtures, enamels, phosphates and sulphates with at least one oxide layer with a refractory ceramic layer, e.g. refractory metal oxide, ZrO2, rare earth oxides or a thermal barrier system comprising at least one refractory oxide layer

Definitions

  • the present invention relates to a process for providing a tortoise-shell chromatic effect to metallic substrates.
  • the present invention relates to a process for providing a tortoise-shell chromatic effect to nickelated components of fire-arms.
  • tortoise-shell effect is a particular spotted chromatic effect conferred for ornamental purposes to tools or metallic parts of devices of varying origins.
  • the tortoise-shell effect is particularly requested for providing an aesthetically pleasant chromatic effect to the action body or other metallic parts of shotguns.
  • the high temperature tortoising process consists in the thermal treatment of a steel matrix which comprises heating to a temperature of about 700° C. and quenching the steel in an aqueous solution of oxidizing salts.
  • the spotted colouring is created by the different surface oxidation degree of the steel and by the different thickness of the oxide layer formed.
  • the thermal treatment required for obtaining the particular aesthetic tortoise-shell effect has a negative influence on the hardness and mechanical performance in general of the metallic component treated.
  • One of the main objectives of the present invention therefore relates to providing a process for giving a tortoise-shell chromatic effect to metallic substrates without having to resort to temperatures which cause distortion of the metals treated.
  • Another objective of the present invention relates to a chemical tortoising process of end-products or metallic components which allows the production of a long-lasting chromatic effect, which is appreciable from an aesthetic point of view.
  • a further objective of the present invention relates to a chemical process capable of providing, at non-high temperatures, a persistent tortoise-shell chromatic effect to nickelated components of fire-arms.
  • a first aspect of the present invention relates to a process for providing a tortoise-shell chromatic effect to substrates which includes the heating of a metallic substrate and application, under heat, on a portion of said metallic substrate, of an oxidizing solution comprising a thiosulfate, a reagent metal and an acidifying compound.
  • the metallic substrate to be treated is heated to a temperature at which there are substantially no thermal distortions which can jeopardize its use in high-precision applications.
  • the oxidizing solution of the invention is typically a solution based on sodium thiosulfate containing a reagent metal conveniently in the form of an acetate, preferably consisting of copper or lead acetate or their mixtures.
  • the term acidifying compound includes compounds with acid hydrolysis or however compounds which when added to an aqueous solution are capable of reducing its pH.
  • Suitable acidifying compounds comprise organic acids such as carboxylic acids, for example, acetic acid, citric acid; oxalic acid, and potassium acid tartrate; inorganic acids such as hypophosphorous acid; salicylic acid; ketones such as acetone; aldehydes such as formic aldehyde and acetic aldehyde and their mixtures.
  • organic acids such as carboxylic acids, for example, acetic acid, citric acid; oxalic acid, and potassium acid tartrate
  • inorganic acids such as hypophosphorous acid
  • salicylic acid ketones such as acetone
  • aldehydes such as formic aldehyde and acetic aldehyde and their mixtures.
  • Substrates suitable for being subjected to the tortoising process of the invention comprise metallic and non-metallic matrixes, provided they have at least one surface portion with a metallic layer, galvanically deposited or with another technology.
  • Plastic matrixes with a nickelated surface, steel matrixes, nickelated steels, metal alloys such as aluminum, copper, nickel alloys and super-alloys, can be used, for example.
  • Nickelated details or components of end-products and articles for varying uses with particular reference to nickelated details for fire-arms, such as gun action bodies, can be appropriately treated with the process of the invention.
  • the application of said oxidizing solution advantageously takes place by means of buffering on localized portions of the metallic substrate to be treated so as to cause oxidation and consequently a chromatic variation, limited to the buffered areas.
  • the surface metal layer undergoes a more intense oxidation process the greater the residence time of the oxidizing solution.
  • An embodiment of the process of the invention comprises the direct development of the chromatic effect on the metallic substrate using a solution based on thiosulfate containing copper acetate as reagent metal.
  • a metallic substrate is heated to a temperature conveniently within the range of 100 to 110° C. and subsequently buffered with a chromatically effective quantity of an aqueous solution containing sodium thiosulfate, copper acetate and potassium acid tartrate, at a temperature advantageously within the range of 40-110° C., preferably 60-80° C., until the development of the desired chromatic variation.
  • the buffering phase can be repeated once or several times, until the desired tonality or chromatic effect is obtained.
  • a first treatment phase which comprises the heating of a metallic substrate to a temperature conveniently within the range of 140-150° C. and the application of a chromatically effective quantity of an aqueous solution containing sodium thiosulfate, lead acetate and an acidifying component, preferably consisting of potassium acid tartrate and, without rinsing;
  • a second treatment phase which comprises the application of a second oxidizing solution to the substrate, conveniently brought to a temperature of 40-80° C., preferably 50-60° C.
  • the application of said second oxidizing solution can be effected by means of buffering or by the direct immersion therein of the metallic substrate.
  • This second oxidizing solution contains a strong oxidizing agent, preferably consisting of ammonium persulfate, preferably present in a quantity ranging from 150-180 g/l.
  • a nickelated steel action body for a shotgun was initially heated to a temperature of 100° C. and subsequently subjected to localized buffering at a temperature of 70° C. with an oxidizing aqueous solution containing 230 g/l of sodium thiosulfate, 35 g/l of copper acetate and 35 g/l of potassium acid tartrate, until a spotted colouring, of the tortoise-shell type, is formed.

Landscapes

  • Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Organic Chemistry (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Materials Engineering (AREA)
  • Mechanical Engineering (AREA)
  • Metallurgy (AREA)
  • Inorganic Chemistry (AREA)
  • General Chemical & Material Sciences (AREA)
  • Ceramic Engineering (AREA)
  • Chemical Treatment Of Metals (AREA)
  • Chemically Coating (AREA)
  • Other Surface Treatments For Metallic Materials (AREA)
  • Farming Of Fish And Shellfish (AREA)
  • Crystals, And After-Treatments Of Crystals (AREA)
  • Water Treatment By Electricity Or Magnetism (AREA)

Abstract

The present invention relates to a chemical process for providing a tortoise-shell chromatic effect to nickelated metallic substrates, which comprises heating the metallic substrate to 100-110 ° C. and subsequent buffering at a temperature of 40-110° C. with an oxidizing solution based on sodium thiosulfate, a reagent metal and an acidifying compound.

Description

  • The present invention relates to a process for providing a tortoise-shell chromatic effect to metallic substrates. [0001]
  • In particular, the present invention relates to a process for providing a tortoise-shell chromatic effect to nickelated components of fire-arms. [0002]
  • It is known that the so-called tortoise-shell effect is a particular spotted chromatic effect conferred for ornamental purposes to tools or metallic parts of devices of varying origins. [0003]
  • In the fire-arm industry, the tortoise-shell effect is particularly requested for providing an aesthetically pleasant chromatic effect to the action body or other metallic parts of shotguns. [0004]
  • A tortoising process of metallic substrates which requires high operating temperatures and also a low temperature chemical process capable of providing a simple uniform colouring to metallic substrates, are currently known. [0005]
  • The high temperature tortoising process consists in the thermal treatment of a steel matrix which comprises heating to a temperature of about 700° C. and quenching the steel in an aqueous solution of oxidizing salts. [0006]
  • The spotted colouring is created by the different surface oxidation degree of the steel and by the different thickness of the oxide layer formed. [0007]
  • This tortoising process of the known art, however, is not without its drawbacks which can mainly be attributed to the distortion of the metallic materials due to the considerable thermal stress to which they are subjected during the quenching operation. [0008]
  • The more reduced the dimensional tolerances of the metallic articles or components treated, the greater this problem becomes. [0009]
  • In the case of the treatment of metallic components for high-precision articles, in fact, even a limited distortion or almost imperceptible deformation of the component can jeopardize its adequacy for the end-use. [0010]
  • In the tortoising processes of gun action bodies, for example, it has been found that even minimum structural distortions can make them unusable. [0011]
  • Furthermore, the thermal treatment required for obtaining the particular aesthetic tortoise-shell effect has a negative influence on the hardness and mechanical performance in general of the metallic component treated. [0012]
  • Viceversa, chemical colouring processes of metals at a low temperature not only have the disadvantage of not being suitable for providing a spotted chromatic effect on the metals but also have the additional drawback that the chromatic layer produced can be easily removed by simple scratching. [0013]
  • With the tortoising techniques currently available, it is consequently not possible to obtain a tortoise-shell chromatic effect which persists with time, is resistant to scratching and does not produce significant distortions of the metallic end-products treated. [0014]
  • The Applicant has now identified a chemical tortoising process which is effected at non-high temperatures and which consequently considerably limits the occurrence of the drawbacks described above. [0015]
  • One of the main objectives of the present invention therefore relates to providing a process for giving a tortoise-shell chromatic effect to metallic substrates without having to resort to temperatures which cause distortion of the metals treated. [0016]
  • Another objective of the present invention relates to a chemical tortoising process of end-products or metallic components which allows the production of a long-lasting chromatic effect, which is appreciable from an aesthetic point of view. [0017]
  • A further objective of the present invention relates to a chemical process capable of providing, at non-high temperatures, a persistent tortoise-shell chromatic effect to nickelated components of fire-arms. [0018]
  • In view of the above objectives and others which will become evident from the following description, a first aspect of the present invention relates to a process for providing a tortoise-shell chromatic effect to substrates which includes the heating of a metallic substrate and application, under heat, on a portion of said metallic substrate, of an oxidizing solution comprising a thiosulfate, a reagent metal and an acidifying compound. [0019]
  • In the process of the invention, the metallic substrate to be treated is heated to a temperature at which there are substantially no thermal distortions which can jeopardize its use in high-precision applications. [0020]
  • The oxidizing solution of the invention is typically a solution based on sodium thiosulfate containing a reagent metal conveniently in the form of an acetate, preferably consisting of copper or lead acetate or their mixtures. [0021]
  • Within the scope of the present invention, the term acidifying compound includes compounds with acid hydrolysis or however compounds which when added to an aqueous solution are capable of reducing its pH. [0022]
  • Suitable acidifying compounds comprise organic acids such as carboxylic acids, for example, acetic acid, citric acid; oxalic acid, and potassium acid tartrate; inorganic acids such as hypophosphorous acid; salicylic acid; ketones such as acetone; aldehydes such as formic aldehyde and acetic aldehyde and their mixtures. [0023]
  • Substrates suitable for being subjected to the tortoising process of the invention comprise metallic and non-metallic matrixes, provided they have at least one surface portion with a metallic layer, galvanically deposited or with another technology. Plastic matrixes with a nickelated surface, steel matrixes, nickelated steels, metal alloys such as aluminum, copper, nickel alloys and super-alloys, can be used, for example. [0024]
  • Nickelated details or components of end-products and articles for varying uses, with particular reference to nickelated details for fire-arms, such as gun action bodies, can be appropriately treated with the process of the invention. [0025]
  • The application of said oxidizing solution advantageously takes place by means of buffering on localized portions of the metallic substrate to be treated so as to cause oxidation and consequently a chromatic variation, limited to the buffered areas. In the areas buffered with the oxidizing solution, the surface metal layer undergoes a more intense oxidation process the greater the residence time of the oxidizing solution. [0026]
  • An embodiment of the process of the invention comprises the direct development of the chromatic effect on the metallic substrate using a solution based on thiosulfate containing copper acetate as reagent metal. [0027]
  • In accordance with this embodiment, a metallic substrate is heated to a temperature conveniently within the range of 100 to 110° C. and subsequently buffered with a chromatically effective quantity of an aqueous solution containing sodium thiosulfate, copper acetate and potassium acid tartrate, at a temperature advantageously within the range of 40-110° C., preferably 60-80° C., until the development of the desired chromatic variation. The buffering phase can be repeated once or several times, until the desired tonality or chromatic effect is obtained. [0028]
  • It has been found that under these conditions, the tortoise-shell chromatic effect is caused by the oxidizing action of the solution on the surface of the metallic substrate. The coloured oxidized layer formed is firmly anchored to the metallic surface producing a long-lasting chromatic effect. [0029]
  • The Applicant has discovered that the direct development of a long-lasting chromatic variation which is particularly appreciable from an aesthetic point of view, is obtained using an oxidizing aqueous solution containing 220-240 g/l of sodium thiosulfate, 30-40 g/l of copper acetate and 30-40 g/l of potassium acid tartrate. [0030]
  • According to another embodiment of the process of the invention, it is possible to obtain the formation of the tortoise-shell effect with a two-phase treatment. This further embodiment of the invention therefore includes: [0031]
  • a first treatment phase which comprises the heating of a metallic substrate to a temperature conveniently within the range of 140-150° C. and the application of a chromatically effective quantity of an aqueous solution containing sodium thiosulfate, lead acetate and an acidifying component, preferably consisting of potassium acid tartrate and, without rinsing; [0032]
  • a second treatment phase which comprises the application of a second oxidizing solution to the substrate, conveniently brought to a temperature of 40-80° C., preferably 50-60° C. The application of said second oxidizing solution can be effected by means of buffering or by the direct immersion therein of the metallic substrate. [0033]
  • This second oxidizing solution contains a strong oxidizing agent, preferably consisting of ammonium persulfate, preferably present in a quantity ranging from 150-180 g/l. [0034]
  • It has been found that the process of the invention allows a variety of chromatic effects and different colourings to be obtained, by simply increasing the contact time of the oxidizing solutions on the surface of the metallic substrates. It is thus possible to produce yellow-gold, red, blue and grey colourings and shades in different tonalities. [0035]
  • The following examples are provided for purely illustrative purposes of the present invention and should not be considered as limiting its protection scope which is clearly defined by the enclosed claims.[0036]
    • EXAMPLE 1
  • A nickelated steel action body for a shotgun was initially heated to a temperature of 100° C. and subsequently subjected to localized buffering at a temperature of 70° C. with an oxidizing aqueous solution containing 230 g/l of sodium thiosulfate, 35 g/l of copper acetate and 35 g/l of potassium acid tartrate, until a spotted colouring, of the tortoise-shell type, is formed. [0037]
    • EXAMPLE 2
  • An aqueous solution containing 230 g/l of sodium thiosulfate, 22 g/l of lead acetate and 25 g/l of potassium acid tartrate was applied with a buffer on a nickel alloy article heated to a temperature of 140° C. In a subsequent phase, the article was immersed or buffered, without rinsing, at a temperature of 60° C., with an aqueous solution containing 160 g/l of ammonium persulfate. After a few minutes, a chromatic variation, with a typical tortoise-shell effect, is formed in the buffered areas. [0038]
    • EXAMPLE 3
  • Oxidizing solutions suitable for use in the buffering phase of the tortoising process of the invention: [0039]
    Sodium thiosulfate 220/240 g/l
    Copper or lead acetate 25-40 g/l
    Citric acid 30-40 g/l
    Sodium thiosulfate 220/240 g/l
    Copper or lead acetate 25-40 g/l
    Hypochlorous acid 0.5 cc/l
    (d = 1, 23 g/cc)
    Sodium thiosultate 220/240 g/l
    Copper or lead acetate 25-40 g/l
    Acetone 40 ml/l
    Sodium thiosulfate 220/240 g/l
    Copper or lead acetate 25-40 g/l
    Formic aldehyde 30 ml/l
    Sodium thiosulfate 220/240 g/l
    Copper or lead acetate 25-40 g/l
    Acetic aldehyde 20-30 ml/l
    Sodium thiosulfate 220/240 g/l
    Copper or lead acetate 25-40 g/l
    Oxalic acid 10-15 g/l
    Sodium thiosulfate 220/240 g/l
    Copper or lead acetate 25-40 g/l
    Salicylic acid 15-20 g/l
    Sodium thiosulfate 220/240 g/l
    Copper or lead acetate 25-40 g/l
    Acetic acid 10 ml/l

Claims (13)

1. A process for providing a tortoise-shell chromatic effect to substrates which comprises heating of the substrate to a suitable temperature for providing a chromatic effect and the application under heat on a portion of said substrate of an oxidizing solution comprising a thiosulfate, a reagent metal and an acidifying compound.
2. The process according to claim 1, characterized in that said thiosulfate is sodium or potassium thiosulfate.
3. The process according to claim 1, characterized in that said metal is selected from copper acetate, lead acetate or their mixtures.
4. The process according to claim 1, characterized in that said acidifying compound is selected from potassium acid tartrate, citric acid, hypophosphorous acid, acetone, formic aldehyde, acetic aldehyde, oxalic acid, salicylic acid, acetic acid and their mixtures.
5. The process according to claim 1, characterized in that said oxidizing solution is applied by buffering on said substrate.
6. The process according to claim 1, wherein there is the direct development of a tortoise-shell chromatic effect by heating said metallic substrate to a temperature within the range of 100-110° C. and buffering at a temperature within the range of 40-110° C. with an oxidizing solution comprising
sodium thiosulfate 220-240 g/l copper acetate 30-40 g/l potassium acid tartrate 30-40 g/l
until the chromatic effect is obtained.
7. The process according to claim 6, characterized in that the buffering of the metallic substrate takes place at a temperature ranging from 60-80° C.
8. The process according to claim 1, wherein a tortoise-shell chromatic effect is developed in two phases, said process comprising:
an application phase by buffering a solution comprising
sodium thiosulfate 220-240 g/l lead acetate 30-40 g/l potassium acid tartrate 30-40 g/l
on a metallic substrate heated to a temperature ranging from 140-150° C. and
a second application phase of a second oxidizing solution on said substrate at a temperature ranging from 40-80° C.
9. The process according to claim 8, characterized in that in said second phase, the application of the oxidizing solution takes place by buffering or by immersion of the metallic substrate.
10. The process according to claim 8, characterized in that said second oxidizing solution is a solution of ammonium persulfate.
11. The process according to claim 1, characterized in that said substrate comprises a metal coating.
12. The process according to claim 11, characterized in that said coating metal is selected from nickel, nickel alloys, steels, nickelated steels, copper, super-alloys.
13. The process according to claim 1, characterized in that said metallic substrate is an action body of a gun.
US10/359,667 2002-02-15 2003-02-06 Process for providing a tortoise-shell chromatic effect to metallic substrates Abandoned US20030159762A1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
IT2002MI000307A ITMI20020307A1 (en) 2002-02-15 2002-02-15 PROCEDURE FOR CONFERRING A TURTLE CHROMATIC EFFECT TO METAL SUBSTRATES
ITMI2002A000307 2002-02-15

Publications (1)

Publication Number Publication Date
US20030159762A1 true US20030159762A1 (en) 2003-08-28

Family

ID=11449265

Family Applications (1)

Application Number Title Priority Date Filing Date
US10/359,667 Abandoned US20030159762A1 (en) 2002-02-15 2003-02-06 Process for providing a tortoise-shell chromatic effect to metallic substrates

Country Status (7)

Country Link
US (1) US20030159762A1 (en)
EP (1) EP1336669B9 (en)
JP (1) JP2003277946A (en)
AT (1) ATE358193T1 (en)
DE (1) DE60312752D1 (en)
ES (1) ES2285035T4 (en)
IT (1) ITMI20020307A1 (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20120000412A1 (en) * 2008-10-22 2012-01-05 University Of Plymouth Method Of Colouring Tin And Tin-Containing Articles

Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4195124A (en) * 1976-04-26 1980-03-25 Sekisui Kagaku Kogyo Kabushiki Kaisha Solar radiation energy absorber
US4631093A (en) * 1984-07-27 1986-12-23 Tre Corporation Chromate free method of treating metal substrates to impart corrosion resistance and color to the substrate surface
US5348767A (en) * 1993-09-02 1994-09-20 Sandor Raymond P Methods for production of faux effects using select color mixtures and blending solvents
US6241830B1 (en) * 1998-08-13 2001-06-05 Nippon Paint Co., Ltd. Non-chromium anticorrosive treatment
US6309476B1 (en) * 1999-05-24 2001-10-30 Birchwood Laboratories, Inc. Composition and method for metal coloring process
US6391181B1 (en) * 1996-05-15 2002-05-21 Nickel Rainbow Limited Articles having a colored metallic coating and process for their manufacture
US20020146651A1 (en) * 2000-07-25 2002-10-10 Osamu Uchida Color developing agent, azo dye, silver halide photographic light-sensitive material, and image-forming method

Family Cites Families (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB1229502A (en) * 1968-05-31 1971-04-21
FR2038796A5 (en) * 1969-03-28 1971-01-08 Seailles Pierre Decorative coating with patina effect for - lampshades etc
SU673667A1 (en) * 1978-02-06 1979-07-15 Предприятие П/Я В-8657 Solution for chemical colouring of ferrous and non-ferrous metals and alloys thereof
SU729281A1 (en) * 1978-04-26 1980-04-28 Воронежский технологический институт Method of light-blue chemical dyeing of copper surface
AUPM529494A0 (en) * 1994-04-26 1994-05-19 Copper Refineries Pty Ltd Artificial patina
FR2735075B1 (en) * 1995-06-07 1997-08-29 Ams Europ PROCESS FOR PROVIDING A METALLIC PATINA APPEARANCE TO A PLASTIC MATERIAL.
LU88726A1 (en) * 1996-03-15 1997-03-15 Brumagne Jean Claude Method for treating the metal surface of a material composed or coated with copper and / or zinc

Patent Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4195124A (en) * 1976-04-26 1980-03-25 Sekisui Kagaku Kogyo Kabushiki Kaisha Solar radiation energy absorber
US4631093A (en) * 1984-07-27 1986-12-23 Tre Corporation Chromate free method of treating metal substrates to impart corrosion resistance and color to the substrate surface
US5348767A (en) * 1993-09-02 1994-09-20 Sandor Raymond P Methods for production of faux effects using select color mixtures and blending solvents
US6391181B1 (en) * 1996-05-15 2002-05-21 Nickel Rainbow Limited Articles having a colored metallic coating and process for their manufacture
US6241830B1 (en) * 1998-08-13 2001-06-05 Nippon Paint Co., Ltd. Non-chromium anticorrosive treatment
US6309476B1 (en) * 1999-05-24 2001-10-30 Birchwood Laboratories, Inc. Composition and method for metal coloring process
US20020146651A1 (en) * 2000-07-25 2002-10-10 Osamu Uchida Color developing agent, azo dye, silver halide photographic light-sensitive material, and image-forming method

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20120000412A1 (en) * 2008-10-22 2012-01-05 University Of Plymouth Method Of Colouring Tin And Tin-Containing Articles
US9163312B2 (en) * 2008-10-22 2015-10-20 University Of Plymouth Method of colouring tin and tin-containing articles

Also Published As

Publication number Publication date
DE60312752D1 (en) 2007-05-10
ITMI20020307A0 (en) 2002-02-15
ES2285035T3 (en) 2007-11-16
ATE358193T1 (en) 2007-04-15
EP1336669B1 (en) 2007-03-28
ES2285035T4 (en) 2008-05-16
EP1336669A2 (en) 2003-08-20
ITMI20020307A1 (en) 2003-08-18
EP1336669A3 (en) 2004-06-30
EP1336669B9 (en) 2007-10-03
JP2003277946A (en) 2003-10-02

Similar Documents

Publication Publication Date Title
JP4762077B2 (en) Hardening method of steel member, hardened steel member and hardened surface protective agent
EP0565029B1 (en) Grain oriented silicon steel sheet having low core loss and method of manufacturing same
CN104995339B (en) Method for producing a chromium coating on a metal substrate
KR20070104612A (en) Coated metal product, method to produce it and use of the method
RU2008145222A (en) METHOD FOR MANUFACTURE OF PROTECTED FROM CORROSION AND HAVING A MIRROR GLOSSY SUBSTRATE
KR101680864B1 (en) Ceramic coating methods of iron-based substrate introduced metal oxide layer for corrosion resistance
NO20050627L (en) Process for the manufacture of corrosion-resistant and decorative coatings and coating systems for metal substrates
US4499123A (en) Process for coating aluminum with zinc
KR100943840B1 (en) Method of treating surface of magnesium product
TW200712226A (en) Method of improving surface properties of the metal and metal with coating layer prepared by the same
DE69019424D1 (en) Electrode for electrolytic processes and process for producing the electrode.
US20030159762A1 (en) Process for providing a tortoise-shell chromatic effect to metallic substrates
TWI351387B (en)
US3029158A (en) Processes of chemical nickel plating of amphoteric and like materials
KR20220000119A (en) Coated steel sheets with high light reflectance and the method of the same
JPS5915984B2 (en) Exterior parts for watches
KR20080105772A (en) Method for manufacturing color metallic material having oxide layer with high corrosion-resistance using etching
JP2010222649A (en) Production method of carbon steel material and carbon steel material
KR101629473B1 (en) Method for Enhancement of Hardness of Metal
JP2001170780A (en) Manufacturing method for titanium plate or titanium- cladded plate
Kautz The effect of iron surface preparation upon enamel adherence
SU1694666A1 (en) Method of manufacturing solid rolled wheels
CN116065118B (en) Method for oxygen permeation of titanium alloy ions
JP4788262B2 (en) Plating film and method for forming plating film.
KR101683077B1 (en) Ceramic coating methods of iron-based substrate introduced Si oxide layer for corrosion resistance

Legal Events

Date Code Title Description
AS Assignment

Owner name: FABBRICA D'ARMI PIETRO BERETTA S.P.A., ITALY

Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNOR:BERETTA, UGO GUSSALLI;REEL/FRAME:013750/0313

Effective date: 20030203

STCB Information on status: application discontinuation

Free format text: ABANDONED -- FAILURE TO RESPOND TO AN OFFICE ACTION