Abstract: A multilayer co-extruded film includes an inner layer positioned at a first surface of the multi-layer film that is intended to be oriented toward an object being wrapped with the film; an outer layer positioned opposite the inner layer at a second surface of the multi-layer film that is intended to be oriented away from the object being wrapped with the film; and at least one core layer positioned between the inner layer and the outer layer. A method for making a biodegradable tensioning film that is composed of an inner layer, an outer layer and one or more core layer positioned therebetween includes extruding a three-layer film on a three-layer extruder. Each of the inner layer, the outer layer and the one or more core layer is primarily composed of a polymeric material that is biodegradable and compostable.

Abstract: A trivalent-chromium chemical conversion coating from which substantially no hexavalent chromium is released. The trivalent-chromium chemical conversion coating is one formed on the surface of a zinc or zinc-alloy deposit. In a brine spray test, the chemical conversion coating has unsusceptibility to corrosion (time required for white-rust formation) of 96 hours or longer. The chemical conversion coating has a hexavalent-chromium concentration less than 0.01 ?g/cm2 in terms of metal atom amount. The amount of hexavalent chromium released after 30-day standing in a thermo-hygrostatic chamber at a temperature of 80° C. and a humidity of 95% (amount of hexavalent chromium released when the coating is immersed in 100° C. water for 10 minutes) is smaller than 0.05 ?g/cm2.

Abstract: The carrier-foil-attached ultra-thin copper foil according to one embodiment of the present invention comprises a carrier foil, a release layer, a first ultra-thin copper foil, a Cu-diffusion prevention layer, an Al layer, and a second ultra-thin copper foil, wherein the release layer may comprise a first metal (A2) having peeling properties, and a second metal (B2) and third metal (C2) facilitating the plating of the first metal (A2).

Abstract: There is provided a coated steel product having a steel product and a coating layer including a Zn—Al—Mg alloy layer disposed on a surface of the steel product, in which the Zn—Al—Mg alloy layer has a Zn phase, the Zn phase contains a Mg—Sn intermetallic compound phase, and the coating layer consists of Zn: more than 65.0%, Al: from more than 5.0% to less than 25.0%, Mg: from more than 3.0% to less than 12.5%, Sn: 0.1% to 20.0% in terms of percent (%) by mass, given amounts of optional elements, and impurities, and has a chemical composition that satisfies the following Formulas 1 to 5: Bi+In<Sn??Formula 1: Y+La+Ce?Ca??Formula 2: Si<Sn??Formula 3: 0?Cr+Ti+Ni+Co+V+Nb+Cu+Mn<0.25??Formula 4: 0?Sr+Sb+Pb+B<0.5.

Abstract: A Zn alloy plated steel sheet having excellent phosphatability and spot weldability and a method for manufacturing the same are provided. In the Zn alloy plated steel sheet including a base steel sheet and a Zn alloy plating layer, the Zn alloy plating layer includes, by wt %, Al: 0.5-2.8%, Mg: 0.5-2.8%, and a remainder of Zn and inevitable impurities, and a cross-sectional structure of the Zn alloy plating layer includes, by area percentage, more than 50% of a Zn single phase structure and less than 50% of a Zn—Al—Mg-based intermetallic compound. A surface structure of the Zn alloy plating layer includes, by area percentage, 40% or less of a Zn single phase structure and 60% or more of a Zn—Al—Mg-based intermetallic compound.

Abstract: A method of collectively producing display panels each having an outline a part of which is curved includes a bonded substrate forming process of bonding substrates in a pair one of which has thin film patterns and forming a bonded substrate 50, a layering process of layering multiple bonded substrates 50 via curing resin 60 and curing the curing resin 60, a grinding process of collectively grinding the substrates in a pair and the curing resin 60 that are outside the thin film pattern on each of the bonded substrates 50B that are layered on each other along the outline and collectively forming edge surfaces of the display panels each having the curved outline, and a separation process of separating each of the bonded substrates 50B that are layered on each other from the curing resin 60.

Abstract: It is preferable that metallic sodium to be loaded to an engine valve used for an internal combustion engine such as automobile engine have high purity. However, conventionally, an organic solvent remaining in micropores on a surface of the metallic sodium have been hardly attracted attention. Provided is a method for purifying metallic sodium including steps of placing metallic sodium containing organic solvent in the micropores thereof in a melting tank which is sealed, and heating the melting tank under reduced pressure to vaporize and remove the organic solvent coating the metallic sodium.

Abstract: A titanium slab for hot rolling comprised of a titanium slab obtain by smelting commercially pure titanium, wherein even if the breakdown process is omitted, the strip shaped coil after hot rolling is excellent in surface properties and a method of smelting that titanium slab are provided. The titanium slab according to the present invention is a titanium slab for hot rolling obtained by smelting commercially pure titanium including the ? phase stabilizing element Fe, wherein the formation of coarse ? phases is suppressed by making the average Fe concentration down to 10 mm from the surface layer of the surface which corresponds to at least the rolling surface of the titanium slab 0.01 mass % or less. A titanium slab obtained by smelting commercially pure titanium can be obtained by cooling until the surface becomes the ? transformation point or less, then reheating it to the ? transformation point or more, and gradually cooling from the slab surface layer.

Abstract: Methods of manufacturing a fuel cell array that include selectively removing portions of a coating layer from a composite layer. The composite layer includes a first surface and a second surface and a first coating is disposed over at least a portion of the first surface. A laser or mechanical tool is used to selectively remove portions of the first coating to form discontinuity regions at predetermined positions in the first coating.

Abstract: Provided is a metal-resin complex in which a metal alloy and a resin composition that are heterogeneous materials are integrated with each other, and more particularly, a method for producing a metal-resin complex capable of improving bonding strength by producing a metal alloy having a more uniform etching surface using an alkaline aqueous solution to which a chelating agent is added and an acid aqueous solution to which the chelating agent and an amic acid are added, and injection-molding the resin composition by using the produced metal alloy.

Abstract: A substrate includes an iron-nickel alloy core or a cobalt-nickel ferrous alloy core, a chromium conversion coating on at least a portion of the core, and an insulating coating on the chromium conversion coating. A method of making a substrate includes: providing an iron-nickel alloy core or a cobalt-nickel ferrous alloy core, applying a chromium conversion coating on at least a portion of the core, and applying an insulating coating on the chromium conversion coating.

Abstract: An acidic, aqueous composition contains a trivalent chromium compound, an organo-functional silane, and a compound of a group IV-B element. The composition protects metal surfaces, preferably aluminum and aluminum alloys, against corrosion and improves their paint adhesion. The trivalent chromium compound may comprise chromium fluoride and optionally others, such as chromium nitrate. The organo-functional silane is preferably an aminopropyltriethoxy silane, and the compound of a group IV-B element is preferably fluorozirconic acid. The composition can either be dried-in-place or rinsed before a further coating layer is applied. The composition may also include at least one polymer having a plurality of both carboxylic functional groups, alone or with hydroxyl groups.

Abstract: A method of preparing an aqueous composition of a chromium III compound, comprising adding hydrogen peroxide to a mixture comprising water and a chromium VI compound in the presence of at least one acid according to the formula H2GF6, in which G is a Group IV-B element. The composition may contain less than 500 ppm of alkali metal ions and less than 200 ppm of halide ions, relative to chromium and may test negative for chromium VI using s-diphenylcarbazide. The composition may be used for treating a metal surface, among other applications.

Abstract: The invention relates to a method for producing a coating layer protecting against corrosion wherein a surface which is to be treated is brought into contact with an aqueous treatment solution containing chromium(III) ions and at least one phosphate compound, wherein the ratio of the molar concentration of the chromium(III) ions to the molar concentration of the at least one phosphate compound (calculated as orthophosphate) lies between 1:1.5 and 1:3. The method improves the corrosion protection of metallic, in particular, zinc-containing, surfaces provided with conversion layers. The decorative and functional properties of the surface are maintained or improved. Furthermore, the known problems resulting from the use of chromium(VI)-containing compounds or from post-treatments with polymer dispersions are avoided.

Abstract: A composition for forming a protective coating on a metal surface includes water; Cr2(GF6)3 in which G is a Group IV-B element; and at least one polymer having a plurality of carboxylic acid groups and at least one polymer having a plurality of hydroxyl groups, and/or at least one polymer having a plurality of both carboxylic acid and hydroxyl groups; wherein the composition contains less than 500 ppm of alkali metal ions and less than 200 ppm of halide ions relative to chromium. A method of forming a protective coating on a metal surface includes contacting the metal surface with the composition.

Abstract: A method of preparing an aqueous composition of a chromium III compound, comprising adding hydrogen peroxide to a mixture comprising water and a chromium VI compound in the presence of at least one acid according to the formula H2GF6, in which G is a Group IV-B element. The composition may contain less than 500 ppm of alkali metal ions and less than 200 ppm of halide ions, relative to chromium and may test negative for chromium VI using s-diphenylcarbazide. The composition may be used for treating a metal surface, among other applications.

Abstract: A method of preparing an aqueous composition of a chromium III compound, comprising adding hydrogen peroxide to a mixture comprising water and a chromium VI compound in the presence of at least one acid according to the formula H2GF6, in which G is a Group IV-B element. The composition may contain less than 500 ppm of alkali metal ions and less than 200 ppm of halide ions, relative to chromium and may test negative for chromium VI using s-diphenylcarbazide. The composition may be used for treating a metal surface, among other applications.

Abstract: Disclosed is an aqueous solution of a chromium salt, in which the oxalic acid content is 8% by weight or less relative to chromium. In the aqueous solution of the chromium salt, the total organic carbon content is 4% by weight or less relative to chromium. The chromium salt is preferably a chromium chloride, a chromium phosphate, or a chromium nitrate. The chromium chloride preferably contains a basic chromium chloride represented by the composition formula Cr(OH)xCly (wherein 0<x?2, 1?y<3, and x+y=3). The chromium phosphate is preferably one represented by the composition formula Cr(H3?3/nPO4)n (wherein n is a number satisfying 2?n?3). The chromium nitrate is preferably a basic chromium nitrate represented by the composition formula Cr(OH)x(NO3)y (wherein 0<x?2, 1?y<3, and x+y=3).

Abstract: A treatment solution that is used to form a chemical coating of trivalent chromium free of hexavalent chromium having uniform black appearance and good corrosion resistance on the surface of zinc or zinc alloy and that attains prolongation of treatment bath lifetime; and a method of forming a black trivalent chromium chemical coating on the surface of zinc or zinc alloy. There is provided a treatment solution for forming of a black trivalent chromium chemical coating on zinc or zinc alloy, comprising trivalent chromium ions, a chelating agent capable of forming a water-soluble complex with trivalent chromium, zinc ions, a sulfur compound and phosphite ions.

Abstract: A processing solution for forming a hexavalent chromium free, corrosion resistant trivalent chromate conversion film on zinc or zinc alloy plating layers comprises: trivalent chromium and oxalic acid in a molar ratio ranging from 0.5/1 to 1.5/1, wherein the trivalent chromium is present in the form of water-soluble complex with oxalic acid; and cobalt ions, which do not form a hardly soluble metal salt with oxalic acid and are stably present in the processing solution without causing any precipitation; wherein the solution reacts with zinc when bringing it into contact with the zinc or zinc alloy plating to form a hexavalent chromium free, corrosion resistant, trivalent chromate conversion film containing zinc, chromium, cobalt, oxalic acid and silicon on the plating.

Abstract: This invention comprises an acidic aqueous solution for treating metal substrates to improve the adhesion bonding and corrosion protection of the metal surface which comprises effective amounts of water soluble trivalent chromium compounds, fluorozirconates, effective amounts of at least one corrosion inhibitors such as benzotriazole, fluorometallic compounds, zinc compounds, thickeners, surfactants, and at least about 0.001 mole per liter of the acidic solution of a polyhydroxy and/or carboxylic compound as a stabilizing agent for the aqueous solution.

Abstract: A processing solution for forming a hexavalent chromium free, corrosion resistant trivalent chromate conversion film on zinc or zinc alloy plating layers comprises: trivalent chromium and oxalic acid in a molar ratio ranging from 0.5/1 to 1.5/1, wherein the trivalent chromium is present in the form of a water-soluble complex with oxalic acid; and cobalt ions, which do not form a hardly soluble metal salt with oxalic acid and are stably present in the processing solution without causing any precipitation; wherein the solution reacts with zinc when bringing it into contact with the zinc or zinc alloy plating to form a hexavalent chromium free, corrosion resistant, trivalent chromate conversion film containing zinc, chromium, cobalt, oxalic acid and silicon on the plating.

Abstract: A low sludge trivalent chromium based conversion coating bath is provided which forms corrosion resistant coatings on aluminum and aluminum alloys by immersion in aqueous solutions containing trivalent chromium ions and fluorometallate ions followed by optional rinsing. Trivalent chromium coated aluminum also serves as an effective base for paint primers.

Abstract: An implantable medical device is made more durable and long-lasting by providing a passivating layer or film on at least a portion of a metal or metal alloy outer surface of an electrically conducting device. An insulating layer is placed on the passivating layer or film. The passivation can be a chemical passivation, and is preferably an acid treatment.

Abstract: Disclosed is an aqueous solution of a chromium salt, in which the oxalic acid content is 8% by weight or less relative to chromium. In the aqueous solution of the chromium salt, the total organic carbon content is 4% by weight or less relative to chromium. The chromium salt is preferably a chromium chloride, a chromium phosphate, or a chromium nitrate. The chromium chloride preferably contains a basic chromium chloride represented by the composition formula Cr(OH)xCly (wherein 0<x?2, 1?y<3, and x+y=3). The chromium phosphate is preferably one represented by the composition formula Cr(H3-3/nPO4)n (wherein n is a number satisfying 2?n?3). The chromium nitrate is preferably a basic chromium nitrate represented by the composition formula Cr(OH)x(NO3)y (wherein 0<x?2, 1?y<3, and x+y=3).

Abstract: Substrates comprising a surface comprising chromium, said surface being adapted to exhibit reduced coefficient of friction and/or increased hardness.

Abstract: ABSTRACT OF THE DISCLOSURE The present invention is directed to a high protection coating process that is particularly useful for substrates in need of corrosion protection. The invention provides methods of applying a non-chrome passivating layer or conversion coating to a substrate and optionally, a secondary conversion or passivating layer to the non-chrome passivating layer or conversion coating, and articles having said coatings thereon.

Abstract: In a preferred embodiment of the present invention, a conversion coating composition comprising chromium (III) ions, cobalt (II) ions, and nitric acid is provided. The coating composition is substantially free of chromium (VI) ions and substantially free of an oxidizing agent. The present trivalent chromium based conversion coating provides corrosion protection equal to or greater than most hexavalent chromium conversion coatings.

Abstract: A metal substrate is provided with a coating that (i) provides substantial corrosion resistance, (ii) makes it possible to shape the substrate by roll forming and similar light cold forming operations without the need for any oil or wax lubricant, and (iii) has good adhesion to subsequently applied paint. This is achieved by coating the metal substrate surface with an aqueous liquid composition that contains acrylate polymer resin, wax, and hexavalent chromium and then drying this coating into place on the surface to produce the desired dry coating.

Abstract: A metal substrate is anodized in a phosphoric acid anodizing solution. The anodized metal substrate is thereafter contacted with a hexavalent chromium free, trivalent chromium containing acid solution to coat the anodized metal substrate. The coated anodized metal substrate can be adhesively bonded to another such treated metal substrate to form a composite article. The resulting article exhibits excellent bonding and corrosion properties.

Abstract: The surface of an aluminum alloy high-temperature processed article containing Mg is heated at a high temperature of 200° C. or above, thereafter the surface is etched with an aqueous solution containing a chelating agent, and then at least one surface treatment selected from hydration oxidation treatment, coating type chromating, coating, anodizing, and alternating current electrolysis in an aqueous alkali solution is further carried out. This method can provide a surface-treated aluminum alloy high-temperature processed article having superior anticorrosion and adhesion of coatings and a good surface appearance, and is effective as a pretreatment for further surface treatment.

Abstract: A process for treating a chromium coating and/or the surface of a chromium alloy to increase hardness, and/or to decrease coefficient of friction; chromium alloys and/or chromium coatings with surfaces having increased hardness and/or decreased coefficient of friction; and, components comprising chromium alloys and/or chromium coatings with surfaces having increased hardness and/or decreased coefficient of friction.

Abstract: A processing solution for forming a hexavalent chromium free, corrosion resistant trivalent chromate conversion film on zinc or zinc alloy plating layers comprises a silicon compound; trivalent chromium and oxalic acid in a molar ratio ranging from 0.5 to 1.5, wherein the trivalent chromium is present in the form of a water-soluble complex with oxalic acid; and cobalt ions, which form a hardly soluble metal salt with oxalic acid and are stably present in the processing solution without causing any precipitation, wherein the solution reacts with zinc when bringing it into contact with the zinc or zinc alloy plating to form a hexavalent chromium free, corrosion resistant, trivalent chromate conversion film containing zinc, chromium, cobalt, oxalic acid and silicon on the plating. This solution can provide a corrosion resistant trivalent chromate conversion film excellent in the corrosion resistance after heating.

Abstract: A surface-treated steel sheet includes a steel sheet, an Al—Zn-base alloy plating layer formed on the steel sheet, a chemical conversion film provided on the alloy plating layer, and a concentric layer of a Cr compound that is formed on the alloy plating layer of the chemical conversion film. The surface-treated steel sheet may include a steel sheet, an zinc-base plating layer formed on the steel sheet, and a film that contains chromium and calcium and that is formed on the zinc-base plating layer.

Abstract: It is an object of the present invention to provide a processing method for preventing elution of lead in a lead-containing copper alloy to prevent lead from eluting from a faucet metal, etc. made of a lead-containing copper alloy, and a drinking water service fitting made of a lead-containing copper alloy in which elution of lead has been prevented. By forming a chromate film on the surface of a lead-containing copper alloy material, it is possible to reduce elution of the lead left in a limited amount on the surface. A drinking water service fitting made of a lead-containing copper alloy is immersed in an alkaline etching solution in a pre-processing step for a nickel chromium plating step to selectively remove lead on the surface of the lead-containing copper alloy material and is then activated in a solution such as sulfuric acid and hydrochloric acid.

Abstract: A method for the immobilization of a radioactive anion on the surface of a metal substrate, said method comprising treating the substrate with an oxidizing agent in the presence of a solution of a radioactive anion which forms an insoluble salt with ions of said metal. Preferably, a binding agent will also be present. Preferably, the metal is silver, the radioactive anion is 125I− and the binding agent comprises bromide ions.

Abstract: The present invention relates to a surface-treated steel sheet coated with a chromate layer having excellent corrosion resistance, fuel resistance and seam weldability, and a chromate solution used for preparing the surface-treated steel sheet. Specifically, the chromate solution of the present invention comprises (a) a main solution prepared by adding to a chrome solution having 0.4 to 0.8 of trivalent chrome composition and 7 to 50 g/l of dissolved chrome, on the basis of the chrome in the chrome solution, 50 to 80 w % of phosphate, 20 to 40 w % of fluoric acid, 300 to 2000 w % of colloidal silica, 5 to 15 w % of sulfuric acid, and 25 to 40 w % of sodium phosphate, and (b) a hardener solution containing added epoxy silane or glycidyl silane of 2 to 10 w % on the basis of total hardener solution, the pH of which is controlled between 2 and 3, wherein 10 to 60 w % of the hardener solution being added to the main solution.

Abstract: The present invention is drawn to a method of lowering the net resistivity of an interconnect by depositing a monomer layer upon an aluminum bonding pad, the treatment thereof to cross link the monomer to form an electrically conductive polymer, and simultaneously, the substantial reduction of alumina, Al2O3, to metallic aluminum. In the method of the present invention, deposition of a monomer layer in a solvent, volatilization of the solvent, and contact with a strong oxidizer such as a potassium permanganate allows for the use of the strong oxidizer without the hindrance of having to deal with a manganese oxide husk on the surface of the aluminum bonding pad. Preferably, the chemical qualities of the monomer will include the tendency to be a reducing agent to the native oxide film of the bonding pad. By selecting a monomer that tends to reduce rather than to oxidize, the problem of thickening the native oxide film is avoided.

Abstract: A method for producing chromium carbide coatings on steel provides a steel component having a surface which is carburized to contain at least about 0.40% by weight carbon and is followed by chromizing the surface to form a chromium carbide coating on the surface.

Abstract: A coated steel material excellent in corrosion resistance and a method of producing the same, wherein a coated steel material has on the surface of the steel sheet a Zn-alloy coating layer containing 1-10 wt % of Mg, 2-19 wt % of Al and 0.01-2 wt % of Si, where Mg and Al satisfy Mg (%)+Al (%)≦20%, the balance being Zn and unavoidable impurities, and has a coating layer structure of a Mg intermetallic compound or the like. As a base metal treatment, it is preferably provided with a Ni coating layer. The coated Zn-alloy coated steel sheet may have provided on the coating layer, as an intermediate layer, a chromate film layer, and, as an upper layer, an organic coating layer. The Zn-alloy coating layer may further contain one or more of 0.01-1 wt % of In, 0.01-1 wt % of Bi and 1-10 wt % of Sn. The coated steel material may be painted.

Abstract: Metal surfaces, particularly the zinciferous surfaces of zinc-coated steel, can be given a chromate conversion coating that is superior in terms of blackening resistance and white rust resistance by drying into place on the surfaces a layer of a treatment liquid that contains water, hexavalent chromium atoms, trivalent chromium cations, nitrate ions and one or more types of metal ions selected from the group consisting of Ni, Co, Zn and Al, the molar ratio of the total of these metal ions to nitrate ions being in the range from 0.05 to 1.0, the molar ratio of trivalent chromium ions to hexavalent chromium atoms being in the range of 0.11:1.0 to 1.0:1.0, and the molar ratio of nitrate ions to total chromium atoms being in the range of 2.1 to 5.5. Preferably, the coating formed has a chromium content of 10 to 100 mg/m2.

Abstract: A method for forming a chromium oxide film on the surface of a stainless steel sample. The method includes: (a) placing a sample having stainless a steel surface into a vacuum furnace, evacuating the vacuum furnace to a pressure of 2×10−7 to 3×10−7 Torr, and heating the vacuum furnace to 450 to 600° C. at a rate of 5 to 10° C./min; (b) maintaining the vacuum furnace for 10 to 20 minutes at a temperature of 450 to 600° C. to remove foreign materials from the surface of the stainless steel sample and to extract chromium atoms from the stainless steel substrate; and (c) supplying oxygen to the vacuum furnace while maintaining the temperature until oxygen partial pressure reaches 1×10−9 to 2.5×10−7 Torr, so the extracted chromium atoms react with oxygen, producing a chromium oxide (Cr2O3) film on the surface of the stainless steel.

Abstract: A water-based surface-treating agent for metallic materials which gives a film highly satisfactory in corrosion resistance, blackening resistance, wet secondary adhesion to topcoatings, low-pollution characteristics (amount of fixed chromium), chemical resistance (especially acid resistance and alkali resistance), etc., while retaining the intact practical liquid stability of conventional chromate-containing resinous coating agents.

Abstract: Slurry coating compositions are provided for metal substrates, particularly nickel or cobalt-containing alloys, that enable inward-type diffusion aluminide coatings having a substantially uniform coating thickness to be formed thereon. Substantially uniform coating thicknesses are achieved independent of applied slurry composition thickness or application method. The slurry coating composition of the invention comprises a Cr—Al alloy containing about 50 wt % to about 80 wt % Cr in the alloy, LiF in an amount greater than or equal to 0.3 wt % of the Cr—Al alloy, an organic binder, and a solvent.

Abstract: A surface-treated sheet for fuel tanks includes a cold-rolled steel sheet with a low carbon content, a zinc or zinc-based alloy plating layer formed on the steel sheet, and a chromate film coated on the zinc or zinc-based alloy plating layer. The chromate film is formed from a chromate solution. The chromate solution includes a subject solution and an aqueous silane solution in an amount ranging from 5 to 50% by weight of the subject solution. The subject solution contains a chrome aqueous solution where the concentration of chrome is in the range of 5-50 g/l and the ratio of trivalent chrome to the chrome content is in the range of 0.4 to 0.8.

Abstract: A process is described for increasing the adhesion of organic coatings to metal surfaces, particularly aluminum and aluminum alloys. The process involves the utilization of an adhesion promoting composition in treating the metal surface prior to application of the organic coating. The adhesion promoting composition comprises a nitro sulfonic acid. A chromating step is optionally employed.

Abstract: A composition and method for coating and touching up a metal surface is provided. The composition contains from about 0.5 to about 240 millimoles per kilograms of a fluorometallate ion, from about 0.5 grams/liters to about 10 grams/liter of phosphorous-containing inorganic oxy anions calculated at their stoichiometric equivalent as H3PO4; from about 0.05 g/l to about 3.5 g/l of hexavalent chromium and from about 0.10 g/l to about 2.20 g/l of trivalent chromium ions.

Abstract: In a chromating solution comprising a water-soluble chromium compound and a reducing agent and in which hexavalent chromium ions produced by dissolution of the water-soluble chromium compound have been partly reduced with the reducing agent to trivalent chromium ions, an oxycarboxylic acid compound is used as the reducing agent. This chromating solution causes neither gelation nor sedimentation of the solution even when hexavalent chromium ions are reduced to trivalent chromium ions at a reduction percentage of more than 50%. The chromating solution and a chromate film formed on a steel sheet may also contain an organic resin, phosphoric acid or a phosphoric acid compound, or a silica sol.

Abstract: A production method for a lead-containing hot-galvanized chromated steel sheet with excellent resistance to blackening and white rust formation comprises: (a) plating a steel sheet in a hot-galvanizing bath containing 0.05-0.3 wt. % lead and 0.1-0.3 wt. % aluminum; (b) coating this with a chromating solution containing chromium (VI) ions, chromium (III) ions and nitrate ions in which the Cr(III)/Cr(VI) molar ratio is 1/9-1/1 and the nitrate ion to total chromium ion molar ratio is 0.1-1.6; and (c) without washing with water, drying the sheet at 40-250 deg. C., to form a 5-50 mg/m integral 2 (in terms of chromium) chromate film.

Abstract: A composition and method for coating and touching up a metal surface is provided. The composition contains from about 0.5 to about 240 millimoles per kilogram of a fluorometallate ion, from about 0.5 grams/liters to about 10 grams/liter of phosphorous-containing inorganic oxy anions calculated at their stoichiometric equivalent as H3PO4; from about 0.05 g/l to about 3.5 g/l of hexavalent chromium and from about 0.10 g/l to about 2.20 g/l of trivalent chromium ions and a surfactant.