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
  • C23F—NON-MECHANICAL REMOVAL OF METALLIC MATERIAL FROM SURFACE; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL; MULTI-STEP PROCESSES FOR SURFACE TREATMENT OF METALLIC MATERIAL INVOLVING AT LEAST ONE PROCESS PROVIDED FOR IN CLASS C23 AND AT LEAST ONE PROCESS COVERED BY SUBCLASS C21D OR C22F OR CLASS C25
  • C23F13/00—Inhibiting corrosion of metals by anodic or cathodic protection
  • C23F13/02—Inhibiting corrosion of metals by anodic or cathodic protection cathodic; Selection of conditions, parameters or procedures for cathodic protection, e.g. of electrical conditions
  • C23F13/04—Controlling or regulating desired parameters
• • 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
  • C23F—NON-MECHANICAL REMOVAL OF METALLIC MATERIAL FROM SURFACE; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL; MULTI-STEP PROCESSES FOR SURFACE TREATMENT OF METALLIC MATERIAL INVOLVING AT LEAST ONE PROCESS PROVIDED FOR IN CLASS C23 AND AT LEAST ONE PROCESS COVERED BY SUBCLASS C21D OR C22F OR CLASS C25
  • C23F13/00—Inhibiting corrosion of metals by anodic or cathodic protection
  • C23F13/005—Anodic protection
• • G—PHYSICS
  • G01—MEASURING; TESTING
  • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
  • G01N17/00—Investigating resistance of materials to the weather, to corrosion, or to light
  • G01N17/02—Electrochemical measuring systems for weathering, corrosion or corrosion-protection measurement
• • G—PHYSICS
  • G01—MEASURING; TESTING
  • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
  • G01N27/00—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means
  • G01N27/02—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means by investigating impedance
  • G01N27/22—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means by investigating impedance by investigating capacitance
• • G—PHYSICS
  • G01—MEASURING; TESTING
  • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
  • G01N27/00—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means
  • G01N27/02—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means by investigating impedance
  • G01N27/22—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means by investigating impedance by investigating capacitance
  • G01N27/223—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means by investigating impedance by investigating capacitance for determining moisture content, e.g. humidity

Definitions

• the present invention relates to a method for protecting structures comprising metal, in particular electrically conductive tracks, deposited on substrates, against corrosion.
• Said structures are generally produced in large series by screen printing of a cooking paste with a high silver content on glass substrates.
• the cooking takes place most of the time at the same time as the heating of the glass for its bending, followed by tempering, if it is a monolithic glass.
• Publication DE-OS 2 231 095 describes the deposition of a dielectric material (lacquer) on structures. conductors used as heating conductors on the surface of a window.
• the publication DE-C1-100 15 430 describes a sensor operating in a capacitive manner to detect condensates on the surface of a glass pane, on the electrodes of which a dielectric passivation layer is deposited.
• the targeted deposition of an additional layer on the already baked structure represents a very troublesome, long and tedious intermediate step in the production process, because it must be carried out with great precision. If such a sensor is, for example, within the range of the wipers, the protective layer wears out over time and must, if necessary, be renewed.
• the publication O-Al-Ol / 07 683 describes a use in this sense for the protection of steel concrete reinforcements against corrosion.
• the steel reinforcement is supplied with a continuous low voltage controlled using an anode system to cancel the differences in surface potential and create a uniform potential, which prevents corrosion.
• the value of the passivation voltage must be determined individually for the material to be protected against corrosion. It is generally possible to determine a marked passivation range as a function of the value of the external voltage or passivation, in which the corrosion current (proportional to the rate of disintegration of the metal) is reduced to the minimum, or even tends towards zero, which means that no further corrosion takes place. In the case external voltages too low, a sufficient corrosion inhibiting effect is not obtained ("active" range), whereas in the case of too high voltages (greater than "ignition potential”), a state called " transpassive ”appears, in which the protective effect no longer acts and the corrosion current again increases significantly.
• the object of this invention is to indicate a process for protecting against corrosion due to weathering of structures comprising metal deposited on substrates, in particular on glass panes, exposed to the weather, and which makes it possible to dispense with a passivating coating. additional on electrically conductive structures.
• the invention is based on the reflection that the conductive surface structures comprising metals, in particular silver, mentioned in the preamble, could also constitute passivable systems which could be protected against corrosion by the application of an appropriate electrical voltage. .
• the arrangement of the conductive structure is decisive.
• a potential difference up to the passivation voltage is necessary between two electrical conductors arranged very close to each other, on the surface of the substrate itself or in another way, not galvanically connected to each other.
• sensors operating in a capacitive manner this can be done in a particularly simple manner.
• antenna structures which can also be capacitively coupled, can be passive using the method described here, on condition of a spatial arrangement. appropriate in relation to an opposite pole. It is thus for example possible to passivate a system composed of a current signal conductor parallel to a ground rail (ground or + 12 V) by selecting a signal amplitude and, if necessary, a frequency signal adapters.
• sensor structures can be very advantageously combined with electrical passivation, if the operating voltage or the measurement voltage of the sensor, which is in any case necessary, is shifted within the range of the passivation voltage.
• the relationship mentioned here has so far not been taken into account and the sensors have been supplied, with the electronics usually available, by a voltage of approximately 3 V ⁇ . However, this tension has no protective passivation effect. Likewise, the usual frequencies for these alternative measurement voltages are below the optimal frequencies.
• the passivation range determined by tests is at voltage values significantly below 3 V. An optimal result (minimum corrosion current) has been determined and verified statistically for 1.1 V and a frequency of 3000 Hz, with a sinusoidal voltage curve.
• the passive range of the material was first determined by a series of tests, for the preparation of practice-oriented tests, in particular the salt spray test according to DIN 50021 with conductive surface structures corrosion-sensitive prints. To this end, a series of test electrodes was produced, on which the material of the surface structures was applied in a thin layer by screen printing on a substrate.
• the screen printing ink consists of a glass frit serving as a base, silver acting as an electrically conductive metal in a proportion of 80%, and, where appropriate, dyes.
• a measuring cell includes a container containing a 5% solution of cooking salt.
• a working electrode made of the material to be tested, a platinum counter electrode and a reference electrode (silver electrode / silver chloride) are immersed in the solution, the potential being noted on the reference electrode at l using a Haber-Luggin capillary tube.
• Appropriate devices have been used for DC and AC voltage tests (potentiostat for DC voltage and function generator for AC voltage).
• a measurement computer with the appropriate software, was used to process the signal.
• test specimens immersed in this measuring cell were initially subjected to tensions continuous in the range of 0 to 4 V (between the test electrodes and the counter electrode).
• test pieces which can be considered identical in the context of industrial manufacturing, are subjected to a compound voltage (alternating voltage superimposed on a direct voltage), the corrosion currents in principle increase markedly. However, it was discovered for a frequency of 3000 Hz an opposite development.

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• Chemical & Material Sciences (AREA)
• Life Sciences & Earth Sciences (AREA)
• Immunology (AREA)
• Pathology (AREA)
• Physics & Mathematics (AREA)
• Health & Medical Sciences (AREA)
• Analytical Chemistry (AREA)
• Biochemistry (AREA)
• General Health & Medical Sciences (AREA)
• General Physics & Mathematics (AREA)
• Engineering & Computer Science (AREA)
• Electrochemistry (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Materials Engineering (AREA)
• Mechanical Engineering (AREA)
• Metallurgy (AREA)
• Organic Chemistry (AREA)
• Biodiversity & Conservation Biology (AREA)
• Ecology (AREA)
• Environmental & Geological Engineering (AREA)
• Environmental Sciences (AREA)
• Investigating Or Analyzing Materials By The Use Of Electric Means (AREA)
• Prevention Of Electric Corrosion (AREA)
• Testing Resistance To Weather, Investigating Materials By Mechanical Methods (AREA)

Applications Claiming Priority (3)

Publications (1)

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Family Applications (1)

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Family Cites Families (7)

• 2003
  • 2003-01-09 DE DE10300388A patent/DE10300388B4/de not_active Expired - Fee Related
• 2004
  • 2004-01-07 JP JP2006502084A patent/JP2006518458A/ja active Pending
  • 2004-01-07 WO PCT/FR2004/000013 patent/WO2004070084A1/fr active Application Filing
  • 2004-01-07 KR KR1020057012834A patent/KR20050097939A/ko not_active Application Discontinuation
  • 2004-01-07 MX MXPA05007048A patent/MXPA05007048A/es unknown
  • 2004-01-07 EP EP04700465A patent/EP1581670A1/de not_active Withdrawn
  • 2004-01-07 CN CNA2004800019553A patent/CN1723298A/zh active Pending

Non-Patent Citations (1)

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