Abstract: A damaged portion treatment method is for treating one or more damaged portions formed in a coated metal material that includes a metal base and a surface treatment film provided on the metal base, the one or more damaged portions reaching the metal base through the surface treatment film. The damaged portion treatment method includes the steps of: disposing a water-containing material to be in contact with one or two out of the damaged portions and one or two electrodes to be in contact with the water-containing material, and electrically connecting, with an external circuit, between the electrode and the metal base, or between the two electrodes; and supplying a current between the electrode and the metal base, or between the two electrodes while alternately switching a direction of the current flowing through the external circuit, with the external circuit.

Abstract: An anticorrosion test method for a coated metallic material may include: a preparation step of adding an artificial flaw at two positions of the coated metallic material; a first measurement step of measuring a size of the artificial flaw; a connection step of electrically connecting the artificial flaws at the two positions by an external circuit via water-containing materials; an energization step of energizing a steel sheet to produce a bulge of an electrodeposition coating film; a second measurement step of measuring size of the bulge of the electrodeposition coating film; a calculation step of calculating a degree of progress of corrosion of the coated metallic material; and a correction step of correcting the degree of the progress of the corrosion.

Abstract: The method for a corrosion resistance test of a coated metal material is an electrochemical method simulating corrosion proceeded by damaged portions in the surface treatment film 4. Two artificially damaged portions 5 spaced from each other in a coated metal material 1 that is obtained by providing a surface treatment film 4 on a metal base 2 are electrically connected to each other by an external circuit 11 via an aqueous electrolyte material 6, and corrosion proceeds by supplying current using one of the artificially damaged portions 5 as an anode site and the other as a cathode site.

Abstract: A physical property evaluation method is the method for evaluating physical properties of a film-shaped measurement target object by means of an electrochemical method, the method including the step of causing an electrolytic solution to contact a front surface of the measurement target object. The speed of penetration of the electrolytic solution into the measurement target object is adjusted in such a manner that the levels of the front-side temperature and the back-side temperature of the measurement target object and a difference between the front-side temperature and the back-side temperature of the measurement target object are adjusted.

Abstract: A corrosion resistance tester for a coated metal material including a surface treatment film on a metal substrate includes: a container placed on the surface treatment film, and having a bottom surface in contact with the surface treatment film, the container including a plurality of water-containing electrolyte material holders that open through the bottom surface; the water-containing electrolyte material contained in each of the water-containing electrolyte material holders of the container, and being in contact with an associated one of a plurality of separate measurement target portions of the surface treatment film; a plurality of electrodes being each in contact with the water-containing electrolyte material contained in an associated one of the water-containing electrolyte material holders; an external circuit connecting the electrodes together; and a conduction means configured to conduct electricity to the metal substrate through the electrodes and the external circuit.

Abstract: Disclosed herein is a method of testing a corrosion resistance of a coated metal material including a surface treatment film on a metal substrate. The method includes: treatment of interposing a water-containing electrolyte material containing water, a supporting electrolyte, and a water penetration enhancer, between a surface of the surface treatment film of the coated metal material and an electrode; holding of the water-containing electrolyte material on the surface of the surface treatment film for one minute to one day; and electrical conduction from the electrode through the water-containing electrolyte material to the coated metal material.

Abstract: A humidity sensor for evaluating the degree of corrosiveness of an environment under a coating has a sensor body including a first metal material and a second metal material which have different standard electrode potentials and which are alternately stacked with an insulating material interposed therebetween. The sensor body has an outcrop in which layers of the first and second metal materials are alternately exposed with a layer of the insulating material interposed therebetween, the outcrop serving as a sensor surface. Humidity is detected based on a corrosion current which flows when a short circuit is caused between the first and second metal materials by humidity on the sensor surface.

Abstract: Disclosed is a humidity sensor for evaluating the degree of corrosiveness of an environment under a coating. The humidity sensor includes a sensor body including a first conductive material and a second conductive material which are alternately stacked with an insulating material interposed therebetween. The sensor body has an outcrop in which layers of the first and second conductive materials are alternately exposed with a layer of the insulating material interposed therebetween, the outcrop serving as a sensor surface. A voltage is applied between the first and second conductive materials, so that humidity is detected based on a current which flows when a short circuit is caused between the first and second conductive materials by humidity on the sensor surface.

Abstract: In a process which is before a treatment process of forming a chemical conversion, TiO2 fine particles as an electron releasing-related substance (electron releasing substance) are attached onto a surface of a vehicle body. Then, a chemical conversion treatment is applied to the vehicle body having the TiO2 fine particles attached thereto. Thereby, an energy band gap of a finally-formed chemical conversion film can be smaller than that of a chemical conversion film formed by using only a chemical conversion treatment agent. Accordingly, the number of electrons (free electrons) which can be supplied onto the surface of a chemical conversion film can be increased during a voltage application in an electrodeposition coating process, and reducing reaction at a cathode can be promoted.

Abstract: The present invention relates to a cured electrodeposition coating film which can be applied on a substrate such as an automobile body. The cured electrodeposition coating film has a dynamic glass transition temperature of 105 to 120° C. and a crosslink density of 1.2×10?3 to 2.0×10?3 mole/cc, and phenol structural part represented with the formula: —C6H4—O— within a range of 0.12 to 0.24 mole in molar number based on a resin solid content of 100 g in the cured electrodeposition coating film.

Abstract: In a process which is before a treatment process of forming a chemical conversion, TiO2 fine particles as an electron releasing-related substance (electron releasing substance) are attached onto a surface of a vehicle body. Then, a chemical conversion treatment is applied to the vehicle body having the TiO2 fine particles attached thereto. Thereby, an energy band gap of a finally-formed chemical conversion film can be smaller than that of a chemical conversion film formed by using only a chemical conversion treatment agent. Accordingly, the number of electrons (free electrons) which can be supplied onto the surface of a chemical conversion film can be increased during a voltage application in an electrodeposition coating process, and reducing reaction at a cathode can be promoted.

Abstract: Disclosed is a chemical conversion treatment agent, which comprises: a film-forming component to form a chemical conversion film in which the number of local low-resistance areas each having an insulation resistance value of 5000? or less is 20 or less/100 ?m2; and at least one kind of fine particles selected from the group consisting of metal fine particles, semiconductor fine particles and electrically conductive organic fine particles.

Abstract: The invention relates to a method for forming a multilayered coating film having a bright feel specific to a metallic coating film and a fineness of a luster color pigment with controlling the miscibility between each coating film when final coatings comprising an intermediate coating composition, a base coating composition and a clear coating composition are applied in this order by a wet-on-wet method to form coating films. The method for forming a multi-layered coating film comprises a step of applying an intermediate coating composition, a base coating composition and a clear coating composition in this order on a substrate formed with an electrodeposition coating film, and a step of baking and curing the applied three layers simultaneously, wherein the base coating composition contains crosslinking polymer microparticles and a nonaqueous dispersion resin.

Abstract: The present invention relates to a cationic electrodeposition coating composition comprising silica particles having pore volume of 0.44 to 1.8 ml/g and average particle size of no more than 10 ?m, the composition showing square root of diffusion coefficient (?Tc) of no less than 2.5 upon diffusing a solution onto a coating film therewith; a cationic electrodeposition coating composition comprising silica particles having pore volume of 0.44 to 1.8 ml/g and average particle size of no more than 10 ?m, wherein the composition shows minimum deposition pH of 11.90 to 12.00 during electrodeposition coating, and film resistance of 1,000 to 1,500 k?·cm2 at film thickness of 15 ?m and applied voltage of 240 V; and an article coated with such cationic electrodeposition coating composition.

Abstract: A method for forming a coated film comprising the steps of sequentially applying an intermediate coating material, a base coating material and a clear coating material on a substrate on which an electrodeposition coated film has been formed; and simultaneously curing the applied three layers by baking, wherein the intermediate coating material comprises: (a) 40 to 56% by weight of an urethane modified polyester resin, the urethane modified polyester resin being obtainable by polyaddition of: a hydroxyl group containing polyester resin which is obtainable by polycondensation of an acid ingredient including not less than 80% by mole of isophthalic acid with a polyhydric alcohol ingredient, with an aliphatic diisocyanate compound; (b) 10 to 30% by weight of a melamine resin; (c) 15 to 30% by weight of a blocked isocyanate compound; (d) 4 to 15% by weight of a nonaqueous dispersion resin having core-shell structure; and (e) 0.4 to 2 parts by weight of a flake-like pigment.

Abstract: An object of the present invention is to provide a method of forming a coated composite film excellent in appearance and anti-chipping property, when an intermediate coating paint and a topcoating paint are coated on a substrate in a wet-on-wet manner. The wet-on-wet coating is performed using an intermediate coating paint containing a urethane-modified polyester resin obtained by a hydroxyl group-containing a polyester resin obtained by polycondensation of a polyhydric alcohol and an acid component containing 80 mol % or more of isophthalic acid, and an aliphatic diisocyanate compound (a); a melamine resin (b); a hexamethylene diisocyanate compound blocked with a compound having an active methylene group (c); a non-aqueous dispersion acryl resin having a core-shell structure (d); and a flake shape pigment (e).

Abstract: A method for forming a coated film comprising the steps of sequentially applying an intermediate coating material, a base coating material and a clear coating material on a substrate on which an electrodeposition coated film has been formed; and simultaneously curing the applied three layers by baking, wherein the intermediate coating material comprises: (a) 40 to 56% by weight of an urethane modified polyester resin, the urethane modified polyester resin being obtainable by polyaddition of: a hydroxyl group containing polyester resin which is obtainable by polycondensation of an acid ingredient including not less than 80% by mole of isophthalic acid with a polyhydric alcohol ingredient, with an aliphatic diisocyanate compound; (b) 10 to 30% by weight of a melamine resin; (c) 15 to 30% by weight of a blocked isocyanate compound; (d) 4 to 15% by weight of a nonaqueous dispersion resin having core-shell structure; and (e) 0.4 to 2 parts by weight of a flake-like pigment.