Abstract: An electrolyte comprising water, an organic solvent selected from the group consisting of a polyethylene glycol, a polyethylene glycol monomethyl ether and mixtures thereof, and a sufficient amount of alkali metal salt of a weak organic acid, so that the electrolyte has a resistivity below about 250 ohm-cm/80° C. A method for differential anodizing porous valve metal body comprising the steps of: anodizing the bodies in a first electrolyte where the cathode surface is placed within an inch of but not in contact with the anode bodies, rinsing the bodies in deionized water, and re-anodizing the bodies in a second electrolyte, where the first electrolyte comprises water, an organic solvent selected from the group consisting of a polyethylene glycol, a polyethylene glycol monomethyl ether and mixtures thereof, and a sufficient amount of alkali metal salt of a weak organic acid so that the first electrolyte has a resistivity below about 250 ohm-cm/80° C.

Abstract: An anodized pressed valve metal powder pellet is described. The anodized pellet is particularly useful as an anode in an electrolytic capacitor having an improved breakdown voltage. The anodized pellet is formed by periodically holding the pellet at a constant voltage and allowing the current to decay over a period of time, or by turning the formation power supply off altogether during the anodization process. Either way provides an opportunity for heated electrolyte to diffuse from the anodized pellet.

Abstract: A process for treating an impregnated electrolytic capacitor anode whereby the anode body is immersed in a liquid electrolytic solution and a voltage is applied to the anode body, whereby a current flows through and repairs flaw sites in the anode body. The liquid electrolytic solution includes an organic solvent comprising at least one of polyethylene glycol, polyethylene glycol monomethyl ether, and polyethylene glycol dimethyl ether. Alternatively, the electrolytic solution includes an organic solvent and an alkali metal phosphate salt. Preferably, the electrolytic solution contains both an alkali metal phosphate salt and an organic solvent comprising at least one of polyethylene glycol, polyethylene glycol monomethyl ether, and polyethylene glycol dimethyl ether.

Abstract: An inventive method of preparing an aluminum foil used in a high voltage aluminum electrolytic capacitor is disclosed. The method involves:(a) immersing an aluminum foil in a first forming solution,(b) applying a first voltage to said aluminum foil immersed in said first forming solution,(c) immersing said aluminum foil to which said first voltage is applied in a second forming solution, without passing current, and(d) applying a second voltage to said aluminum foil immersed in said second forming solution.Also disclosed is an aluminum foil that renders an electrolytic capacitor having properties of both high electrostatic capacity and small leak current.

Abstract: A method for making a master used in the production of optical information carriers having a relief structure, the relief structure representing data. The steps to obtain the relief structure involve: covering a substrate with a first blocking material, removing the first blocking material in a predetermined pattern to produce a first set of open regions where the substrate is exposed and a set of closed regions where the substrate remains covered, and growing an active material layer in a first subset of the first set of open regions to a predetermined thickness, that thickness representing a first data value. The active material is grown by anodization or electroplating in the open regions. The invention also provides for covering the active material layer, removing predetermined portions of the first blocking material to uncover a second subset of open regions, and growing the active material in that second subset of open regions to a thickness representing a different data value.

Abstract: The present invention relates to a vacuum chamber and chamber parts made of aluminum or its alloys which exhibit excellent corrosion resistance to a corrosive gas or plasma introduced into the vacuum chamber, the surface treatment, and material for the vacuum chamber. The vacuum chamber has a porous layer with a structure in which a pore diameter at the top thereof is small, while a pore diameter at the bottom thereof is large. In order to give such a structure to the porous layer, a final anodizing voltage is set to be higher than an initial anodizing voltage when the surface of the base material is anodized. After the porous-type anodizing is completed, non-porous type anodizing may be conducted so as to grow a barrier layer. Furthermore, the base material made of aluminum alloy preferably has particles such as precipitates and/or deposits with a diameter of 10 .mu.m or less in average, and the precipitates and/or deposits are arranged in parallel with a largest surface of the base material.

Abstract: A colored anodic coating for use on surfaces of substrates, e.g. aluminum substrates in which it is desirable to maintain a high solar absorptance (a) and a high infrared emittance (e), particularly in low earth orbit space environments. This anodic coating is preferably a dark colored coating, and even more preferably a black coating. This coating allows a touch temperature within an acceptable design range to preclude burning of an astronaut in case of contact, but also allows a solar radiation absorption in an amount such that an a/e ratio of unity is achieved. The coating of the invention comprises a first layer in the form of an acid anodized colored anodic layer for achieving a high solar absorptance and a second or high emittance layer in the form of a clear acid anodized layer for achieving a high emittance. The entire coating is quite thin, e.g. 1-2 mils and is quite stable in a hostile space environment of the type encountered in a low earth orbit.

Abstract: A method for forming solid electrolytic capacitors provides for anode lead and body surface with increased dielectric thickness as distinguished from a dielectric thickness formed within the inner anode body such that a capacitance value associated therewith is not substantially decreased. The method includes the steps of anodizing the anode to form a predetermined dielectric thickness on the anode and then soaking the anode in a solvent to impregnate an inner portion thereof with the solvent. The solvent is removed from surface areas desired to be coated by a further dielectric layer and thereafter again anodized whereby additional dielectric build-up is limited to the solvent free areas. The solvent is driven off resulting in a capacitor preform which is reinforced by thickened dielectric without capacitance loss which would result from depositing additional dielectric interiorly in the areas insulated from build-up by the solvent.

Abstract: An improved method of anodizing aluminum which produces an oxide surface receptive to the formation of strong and durable bonds with epoxy adhesives and coatings with underlying bulk properties providing dissimilar metal separation and basic corrosion protection. The invention provides a two step electrolytic process which includes, firstly, anodizing the aluminum with a phosphoric acid solution and then, secondly, further anodizing the aluminum with a sulfuric and boric acid solution. A product is provided that has a final coating having two anodized regions. The first outer region produced by the phosphoric acid solution is about 3000 angstroms thick and is characterized by open pores which is particularly well suited for the establishment of stable, strong and durable bonds with epoxy primers and adhesives. The second base region produced by the sulfuric/boric acid solution provides a thick, tough, corrosion resistant region about 15,000 angstroms thick.

Abstract: A broad range of colors within the visible spectrum can be obtained by light interference and multiple refraction in an anodized aluminum product, by electrolytically depositing on an aluminum-based substrate an aluminum oxide anodic film separated from the substrate by an aluminum/aluminum oxide interface. The aluminum oxide anodic film comprises at least three superimposed aluminum oxide anodic layers having different porosities and separated by interfaces between each other, the innermost one of said anodic layers having a non porous barrier layer arranged between the bottom of the pores thereof and the aluminum/aluminum oxide interface. Pigmentary inorganic material is deposited within the pores of the superimposed anodic layers and at least in portions of the interfaces between them, the different colors being produced by varying the current and/or time conditions when depositing the innermost one of the aluminum oxide anodic layers.

Abstract: A method for producing protecting layers on a metal selected from aluminum, titanium and zirconium, or alloys thereof, involves at least two anodic oxidation steps producing oxide layers and a thermal treatment which is carried out before or simultaneously with last anodic oxidation step. The treated metal according to the invention is protected even at high temperatures and under conditions of thermal cycling.

Abstract: A method for changing a metal body, especially an aluminum alloy body, and, in particular, a method for producing a uniform metal body surface for use in achieving desired light reflectance characteristics and/or other useful attributes. The method comprises (a) preparing a metal body in a first solution by producing a first coating on at least a desired portion thereof with the first coating providing a substantially continuous outer surface on the metal body and (b) treating the metal body to achieve substantial uniformity throughout the desired portion of the metal body. In the treating step, substantially all of the first coating is removed in a second solution. The metal body has a substantially uniform roughened surface after the treating step which is sufficient to substantially optimize diffusive reflectance and reduce spectral reflectance of the metal body surface. The preparing step is preferably accomplished by anodizing.

Abstract: A twice-anodized aluminum substrate is anodized sequentially in first and second aqueous electrolytes. In the first, the substrate is conventionally anodized to produce (i) a porous anodic oxide layer having open pores and a passivation layer thereunder. The substrate, now singly-coated, is then anodized in the second electrolyte of an aqueous solution of an organophosphorus compound which generates a residue which is chemisorbed and covalently bonded to the substrate to form (ii) a monomolecular essentially continuous monolayer on the outer surface of (i), and at the same time, the second anodizing step produces (iii) a barrier layer of non-porous aluminum oxide under (i). The thickness of this barrier layer can be increased as a function of the voltage used while maintaining the thickness of (i) substantially constant, and (ii) protects (i) from dissolution.

Abstract: A method for producing protecting layers on a metal selected from aluminum, titanium and zirconium, or alloys thereof, involves at least two anodic oxidation steps producing oxide layers and a thermal treatment which is carried out before the last anodic oxidation step. The treated metal according to the invention is protected even at high temperatures and under conditions of thermal cycling.

Abstract: A process for producing a released film made of at least two layers, one or more of which has been formed by a vapor deposition technique. The process involves anodizing a metal substrate comprising a valve metal or valve metal alloy to form an anodic oxide layer on the substrate, the anodization being carried out in the presence of an adhesion-reducing agent (e.g. fluoride) which makes the anodic layer detachable from the valve metal, coating the anodic layer with one or more layers of desired materials by a vapor deposition technique (e.g. sputtering or vacuum evaporation, etc.) to form a film of desired structure which is releasable from the metal substrate, and then detaching the releasable film from the metal substrate. The film can, if desired, be transferred to another substrate by attaching the other substrate to the releasable film before the releasable film is detached from the metal substrate.

Abstract: The invention relates to a method of producing aluminum capacitor foil adapted for use in high voltage AC motor start capacitors. Aluminum foil is electrolytically etched in a hot aqueous solution of sodium cloride and then immersed in a hot solution of nitric acid. The foil is immediately thereafter passivated in a dilute aqueous solution of phosphoric acid. The passivated foil is electrolytically treated at a first voltage of at least 150 but not greater than 250 volts in a solution of an ammonium salt of a phosphate, a silicate or a vanadinate to substantially reduce the leakage current, and further electrolytically treated at a second voltage of a magnitude about twice that of the first voltage in a solution of an ammonium salt of an aliphatic dicarboxylic acid of at least 9 carbon atoms and ammonium phosphate until an essentailly amorphous oxide is formed on the foil.

Abstract: Capacitor structure capable of achieving increased energy storage density is disclosed together with a fabrication sequence for the capacitor and its anodic oxide dielectric material. Soft porous aluminum oxide which has been formed in a first anodization step and has been densified or transformed to hard barrier oxide in a second anodization step is preferred for the capacitor dielectric material. The first anodization may be performed in a sulfuric acid electrolyte while the second anodization may be performed in a boric acid electrolyte. The boric acid may be diluted with ethylene glycol. The disclosed capacitor is fabricated on a silicon wafer substrate.

Abstract: A process for manufacturing a solid state electrolytic capacitor having on an anode a dielectric coating layer and a solid state electrolytic layer, comprises the steps of forming a conductive polymer compound layer as the solid state electrolytic layer, and subsequently forming the dielectric coating layer by anodizing.

Abstract: An improved valve metal electrolytic capacitor is disclosed, such as an aluminum electrolytic capacitor, as well as a method of making same wherein the improvement comprises forming a hydration resistant composite layer on the valve metal, including a valve metal oxide dielectric layer, by anodizing the valve metal in an aqueous phosphorus-containing organic electrolyte selected from the class consisting of phosphonic acid, phosphinic acid and mixtures of the same dissolved in an aqueous liquid to provide an electrolytic capacitor with increased resistance to hydration.

Abstract: A process for producing a two phase metal/oxide film. The process comprises forming a porous oxide film on a substrate, introducing a weakened stratum into the oxide film so that the film (or at least an outer part of the film) can be subsequently detached along the weakened stratum, depositing a metal on and/or within the pore of the film, and detaching at least the outer film part from the substrate. The detached film so produced can be used for many purposes depending on the film thickness, position of the metal deposits on or with the pores etc. Examples include optical interference devices, magnetic media, coatings for plastics and paper, etc.