US3751349A - Method for electrolytically forming a coating of titanium-alkaline earth metal compound oxide - Google Patents

Method for electrolytically forming a coating of titanium-alkaline earth metal compound oxide Download PDF

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Publication number
US3751349A
US3751349A US00127648A US3751349DA US3751349A US 3751349 A US3751349 A US 3751349A US 00127648 A US00127648 A US 00127648A US 3751349D A US3751349D A US 3751349DA US 3751349 A US3751349 A US 3751349A
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United States
Prior art keywords
titanium
alkaline earth
coating
earth metal
compound oxide
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Expired - Lifetime
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US00127648A
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English (en)
Inventor
H Nozaki
M Yamazaki
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Stanley Electric Co Ltd
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Stanley Electric Co Ltd
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Publication date
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    • C—CHEMISTRY; METALLURGY
    • C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
    • C25B—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES FOR THE PRODUCTION OF COMPOUNDS OR NON-METALS; APPARATUS THEREFOR
    • C25B11/00—Electrodes; Manufacture thereof not otherwise provided for
    • C25B11/04—Electrodes; Manufacture thereof not otherwise provided for characterised by the material
    • C25B11/051—Electrodes formed of electrocatalysts on a substrate or carrier
    • C25B11/073—Electrodes formed of electrocatalysts on a substrate or carrier characterised by the electrocatalyst material
    • C25B11/075—Electrodes formed of electrocatalysts on a substrate or carrier characterised by the electrocatalyst material consisting of a single catalytic element or catalytic compound
    • C—CHEMISTRY; METALLURGY
    • C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
    • C25D—PROCESSES FOR THE ELECTROLYTIC OR ELECTROPHORETIC PRODUCTION OF COATINGS; ELECTROFORMING; APPARATUS THEREFOR
    • C25D11/00—Electrolytic coating by surface reaction, i.e. forming conversion layers
    • C25D11/02—Anodisation
    • C25D11/26—Anodisation of refractory metals or alloys based thereon

Definitions

  • this invention relates to a method for forming a coating of titanium-alkaline earth metal compound oxide on the surface of metallic titanium.
  • Titanium oxide has several characteristic properties such as high dielectric constant, and high responses to temperature in respect of the electric resistance and electrostatic capacitance, accordingly if it is possible to obtain a stable and durable coating made of titanium-alkaline earth metal compound oxide on the surface of titanium, various uses will be expected.
  • the inventors have carried out extensive experiments in order to obtain satisfactory coating on the surface of titanium, and as the result, the inventors have found the method for forming said coating film on the surface of titanium, the method of which will be described in the following.
  • an aqueous solution of hydroxides or salts of alkaline earth metals is employed as electrolytic bath, and any metallic titanium material is employed as one electrode for the electrolysis by using alternating current.
  • Said compound oxide coating containing alkaline earth metal can be formed by oxidizing the surface of titanium by means of alternating current electrolysis using said aqueous solution and said titanium electrode.
  • the surface of titanium may be preferably treated with alternating current electrolysis in a dilute sulfuric acid solution bath in advance of the aforementioned electrolysis in the solution of hydroxides or salts of alkaline earth metals, by which more preferable coating can be obtained.
  • compound oxide in accordance with the method of the present invention contains oxides of alkaline earth metals which have been used for the electrolytic bath, and the compound oxide has various characteristics and utilities as disclosed in the following.
  • a small sized electrostatic capacitor with large capacitance can be made by using said oxide coating on the surface of titanium.
  • (C) Oxide of titanium has anticorrosive property, therefore it can be used for anticorrosive containers, machine parts and accessories.
  • the metallic titanium having the coating formed in accordance with the method of the invention has various utilities, which can be obtained only by the method of the present invention.
  • the preliminary electrolysis is carried out in a dilute aqueous sulfuric acid solution with the concentration of from 10 to 20% by weight, in which a metallic titanium plate is used as an electrode, a platinum or a graphite electrode is used as another electrode, 50 cycles alternating current is used as electric source, and the electrolysis is carried out for 1 to 3 hours under the current density of 50 to ma./cm. as for said titanium plate-.- Thereafter, the titanium plate is rinsed with pure water.
  • this preliminary electrolysis step is taken effect in order to improve the formation of the coating, and it can be omitted without serious disadvantages.
  • the main electrolysis is carried out in a bath consisting of, for example, saturated solution of barium hydroxide [Ba(O'H) -8H O], in which the aforementioned pretreated or not pretreated titanium plate is used as one electrode, a platinum or a graphite plate is used as another electrode, 50 cycles alternating current is employed as the electric source, and the electrolysis is carried out for 30 minutes to 2 hours under the current density of 50 to 100 ma./cm, then for 30 minutes to 2 hours under the current density of 75 to Ina/cm. and further it is continued for 1 hour to 3 hours under the current density of 100 to ma./cm. thus the surface oxidation can be effected.
  • a bath consisting of, for example, saturated solution of barium hydroxide [Ba(O'H) -8H O]
  • the aforementioned pretreated or not pretreated titanium plate is used as one electrode
  • a platinum or a graphite plate is used as another electrode
  • 50 cycles alternating current is employed as the electric source
  • the temperature of the electrolytic bath may be made between 20 to 70 C., and the aforementioned saturated solution of barium hydroxide is those saturated at the respective temperatures.
  • 100 g. of the saturated solution contains 3 g. of barium as barium oxide (BaO) at 20 C. and 10 g. at 50 C.
  • the titanium plate is then rinsed with pure water to obtain a titanium plate coated with titanium-alkaline earth metal compound oxide of the present invention.
  • the compound oxide thus obtained is a stiff and polycrystalline film in the thickness of from 2 to 3 microns, and it contains barium.
  • the dielectric constant and electric conductivity thereof show transient phenomena by a rapid change of the temperature.
  • EXAMPLE Alternating current electrolysis was carried out with using metallic titanium plate as one electrode and a graphite plate as another electrode.
  • the conditions for the electrolysis were as follows:
  • Electrolytic bath (aq. sulfuric acid soln.) .wt. percent 15 Frequency of power sources cycles 50 Current density ma./cm. 75 Time of electrolysis hours 2
  • the titanium plate which was treated with the above preliminary electrolysis, was further treated with electrolysis in an aqueous barium hydroxide solution by changing the current densities step by step as follows:
  • a method for electrochemically forming a coating of titanium-alkaline earth metal compound oxide on the surface of titanium used as one of the electrodes in an electrolysis which comprises carrying out an electrolytic reaction employing titanium metal for only one of the electrodes and an aqueous solution consisting essentially of an alkaline earth metal hydroxide or salt thereof as the electrolyte, and employing an alternating current power source, wherein the electrolysis is carried out for 30 minutes to 2 hours under a current density of 50 to ma./cm. then for 30 minutes to 2 hours under a current density of 75 to ma./crn. and then for 1 hour to 3 hours under a current density of 100 to ma./cm.
  • one electrode employed in the electrolytic reaction is a platinum or graphite electrode.

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  • Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Electrochemistry (AREA)
  • Materials Engineering (AREA)
  • Metallurgy (AREA)
  • Organic Chemistry (AREA)
  • Inorganic Compounds Of Heavy Metals (AREA)
  • Fire-Detection Mechanisms (AREA)
  • Fixed Capacitors And Capacitor Manufacturing Machines (AREA)
  • Control Of Temperature (AREA)
  • Chemically Coating (AREA)
  • Electrochemical Coating By Surface Reaction (AREA)
  • Apparatuses And Processes For Manufacturing Resistors (AREA)
  • Thermally Actuated Switches (AREA)
  • Inorganic Insulating Materials (AREA)
US00127648A 1970-03-27 1971-03-24 Method for electrolytically forming a coating of titanium-alkaline earth metal compound oxide Expired - Lifetime US3751349A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP45025270A JPS5040480B1 (enExample) 1970-03-27 1970-03-27

Publications (1)

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US3751349A true US3751349A (en) 1973-08-07

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US (1) US3751349A (enExample)
JP (1) JPS5040480B1 (enExample)

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0146284A1 (en) * 1983-11-29 1985-06-26 Sony Corporation Methods of manufacturing dielectric metal titanates
EP0408326A1 (en) * 1989-07-10 1991-01-16 Research Development Corporation of Japan Method for manufacturing a composite oxide thin film
RU2278910C1 (ru) * 2004-12-27 2006-06-27 Пензенский государственный университет Способ изготовления сегнетоэлектрических покрытий

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0146284A1 (en) * 1983-11-29 1985-06-26 Sony Corporation Methods of manufacturing dielectric metal titanates
EP0408326A1 (en) * 1989-07-10 1991-01-16 Research Development Corporation of Japan Method for manufacturing a composite oxide thin film
US5427678A (en) * 1989-07-10 1995-06-27 Research Development Corporation Of Japan Composite oxide thin film
RU2278910C1 (ru) * 2004-12-27 2006-06-27 Пензенский государственный университет Способ изготовления сегнетоэлектрических покрытий

Also Published As

Publication number Publication date
JPS5040480B1 (enExample) 1975-12-24

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