US3878078A - Apparatus and process for applying electrodeposition painting by alternating current - Google Patents

Apparatus and process for applying electrodeposition painting by alternating current Download PDF

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US3878078A
US3878078A US288400A US28840072A US3878078A US 3878078 A US3878078 A US 3878078A US 288400 A US288400 A US 288400A US 28840072 A US28840072 A US 28840072A US 3878078 A US3878078 A US 3878078A
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electrode
oxide film
film
bath
set forth
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Tadashi Tanaka
Tatsuro Obi
Yoshio Shindow
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Nippon Steel Corp
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Nippon Steel Corp
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    • C—CHEMISTRY; METALLURGY
    • C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
    • C25D—PROCESSES FOR THE ELECTROLYTIC OR ELECTROPHORETIC PRODUCTION OF COATINGS; ELECTROFORMING; APPARATUS THEREFOR
    • C25D13/00—Electrophoretic coating characterised by the process
    • C25D13/18—Electrophoretic coating characterised by the process using modulated, pulsed, or reversing current

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  • This invention is fora process ofeleetrodeposition painting by an a.c. voltage to popularize the technique of electrodeposition painting and to permit a converter from a.c. to direct current (designated hereinafter as d.c.) to be omitted and therefore to simplify the necessary electric devices.
  • the present invention may be summarized to be a process for applying electrodeposition painting by a.c. comprising applying painting by an a.c. voltage in a resin bath for the electrodeposition painting using an oxide film electrode as counter-electrode of a filmforming metal such as Ta. Al. Ti. Zr and Nb and an alloy thereof.
  • processes for electrodeposition painting so far used comprises applying an external d.c. voltage between a metallic matter to be coated as anode and a counter-electrode or cathode in a bath for the electrodeposition painting containing an electrodeposition paint material. and painting the surface of the metallic matter with the deposited paint material.
  • processes for electrodeposition painting so far used comprises applying an external d.c. voltage between a metallic matter to be coated as anode and a counter-electrode or cathode in a bath for the electrodeposition painting containing an electrodeposition paint material. and painting the surface of the metallic matter with the deposited paint material.
  • Most other processes are modifications of the above process.
  • a special bath of paint material is used for the a.c. electrodeposition painting.
  • the paint material is deposited on the counter-electrode. though it does not need to be coated. and a device is necessary to remove the paint material which. to the contrary. loses the merit of the electrodeposition coating method by a.c.
  • the coulombic efficiency, or amount of paint material deposited in mg/dm per unit coulomb. is small relative to that in the method using d.c.
  • the present invention has succeeded in solving these difficulties profitably and developing a practical process for the electrodeposition painting by a.c.
  • Difficulties generally accompanying with the proeesses for the electrodeposition painting by a.c., such that a thick coating film is not obtained and that the coulombic efficiency is low. arise from the mode of treatment in which the a.c. voltage is directly applied between a metallic material to be coated and the counter-electrode, where the metallic material is alternatingly polarized as anode and cathode in accordance with the cycle of the a.c. voltage source so that the coating film that is formed when the material is anodic is inevitably dissolved or peeled in part when the polarity is reversed.
  • the electrical resistance between both electrodes is made lower. hence the bath current larger.
  • the metallic material to be coated is anodic and the counter-electrode is cathodic. and therefore the coating process to the metal surface proceeds regularly.
  • the resistance between both electrodes is made higher and hence the bath current smaller so that the deposited coating film on the surface of the metallic material is not easily dissolved or peeledl
  • a more perfect process for .the electrodeposition painting has been completed by compensating the undesired current which flows when the metallic matter to be coated is cathodic and the counter-electrode is anodic.
  • the characteristic feature of the process of this invention is that all the requirements in realizing electrodeposition painting by an a.c. voltage have been met solely by modifying the counter-electrode without introducing a sophisticated set of apparatus.
  • the feature of the counter-electrode employed in the process of the present invention is that the electrical resistance and the electrostatic capacitance between the electrode and the paint material bath are large when the electrode is anodic while they are small when cathodic.
  • FIG. I shows the relation between the bath voltage and the bath current when a sinusoidal a.c. voltage is used in the process of this invention, where (i) shows the bath voltage. (ii) the bath current depending on the polarity of voltage and (iii) the bath current when uneffective current is compensated with electrostatic capacity.
  • FIG. 2 shows the coulombic efficiency in the a.c. electrodeposition coating when the tantalum oxide film electrode is used.
  • FIG. 3 shows the ratio in coulombic efficiency of the a.c. electrodeposition painting with the tantalum oxide film electrode to the d.c. method.
  • FIG. 4 shows the coulombic efficiency in the a.c. electrodeposition painting when the aluminum oxide film electrode is used.
  • FIG. 5 shows the ratio in coulombic efficiency of the a.c. electrodeposition painting with the aluminum oxide film electrode to the d.c. method.
  • FIG. 6 shows the relation between the time for electrodeposition and the amount of paint material deposited in the period when a tin-plated iron plate is coated by the a.c. electrodeposition using the tantalum oxide film electrode.
  • FIG. 7 shows the relation between the bath voltage and the amount of paint material deposited when a tinplated iron plate is coated by electrodeposition using the tantalum oxide film electrode.
  • FIG. 8 shows the relation between the cycle of the sinusoidal alternating current and, the ratio in the coulombic efficiency.
  • FIG. 9 shows the relation between the bath voltage and the bath current in electrodeposition coating when alternating currents of various wave forms are used.
  • FIGS. 10 show a modification of the present invcntion.
  • FIG. 10 shows the principle of the modification of the present invention.
  • FIG. 1 I is a graph for explaining the bath current.
  • FIG. 12 shows the relation between the area ratio of the third electrode and pin holes in the coating film.
  • FIG. 13 is a graph for explaining the area ratio of the third electrode and the coulombic efficiency.
  • FIG. 14 shows the position of the third electrode and FIG. 15 explains the behavior of the third electrode in relation to the current elements.
  • the electrical resistance between the counterelectrode and the paint material bath is high and low when the electrode is anodic and cathodic. respectively.
  • the metallic material to be coated is positive and the counter-electrode is negative or. in other words. the paint material is deposited on the surface of the metallic material.
  • the resistance between the counter-electrode and the solution is low enough to allow a large bath or a forward current to flow.
  • high resistance between the counterelectrode and the solution causes the bath current or the current in the inverse direction to be low and suppress the re-dissolution and peeling of the paint coating films formed on the surface of the metallic material to be coated.
  • the loss can be compensated by the electrostatic capacitance when the Namely. when the counter-electrode is anodic. the phase of the bath current leads the bath voltage due to the capacitance.
  • the phase of the bath current leads the bath voltage due to the capacitance.
  • the counter-electrode of the present invention has an oxide film on the surface prevents the coating resin from completely depositing on the electrode surface.
  • the electrode forms a current leading in phase due to the electrostatic capacitance so that the coating film once formed is dissolved while acting as anode and. therefore. the loss in bath voltage due to the resistance of coating film can be kept low.
  • the counter-electrode having the specified properties outlined above permits electrodeposition painting by a.c. to be performed with much counter-electrode is anodic.
  • the counter-electrode having the above properties is required.
  • Such an electrode can be prepared from a film-forming metal such as Ta. Al. Ti. Nb. Zr. Y. Hf. Cr. Mo. W. Bi. Mg. Ge. V and Si and alloys thereof by forming an oxide film on the surface by a chemical or electrochemical manner.
  • a tantalum plate. after a pre-treatment immersing for about 10 sec. in a solution containing H 50 HNO and HF in the ratio 5 2 2). is anodically treated for l() to 120 min. by d.c. voltage using a carbon cathode in a 15 percent solution of boric acid at C.
  • the oxide film formed on the surface has the thickness as shown in Table 1 depending on the voltage applied to the bath.
  • Table I shows the oxidation treatment of the tantalum and the film thickness.
  • the procedure is the same as for tantalum.
  • the oxide film forming process is followed for 5 to 300 min. in an electrolysis solution containing substances of moderate dissolving power such as H 80. and under a 3.0 to 200 V d.c. or a.c. voltage. so as to achieve sufficiently high resistance between the electrode and the solution when the former is anodic.
  • the electrostatic capacitance is ensured therebetween.
  • the coulombic efficiency of the electrode thus formed is close to that of the electrodeposition painting by a d.c. process if sufficient treatment of the oxide film formation has been performed. as shown in FIGS. 4 and 5.
  • An aluminum electrode can be provided with the property of the counter-electrode of this invention by treating to form an oxide film on the surface by many procedures. as is the case with tantalum.
  • electrolytic oxidation in solutions of sulfuric. chromic and boric acids are not restricted to those mentioned above.
  • Film-forming metals such as Ti. Zr and Nb and alloys thereof could provide the counter-electrode which have necessary properties required to achieve the process of this invention by being treated to form oxide films in fundamentally the same way as before.
  • the oxide film should be especially stable and uniformly formed on the electrode surface. If otherwise. the oxide film may be deteriorated or broken to fall off due to evolution of hydrogen gas when serving as a cathode and likely deposition of resin on the electrode surface and deterioration of the electrostatic capacity may result when serving as an anode. anodic general. thickness of oxide films is important with the oxide films which is required to form the electrodes of the present invention. ln particular. for the metals of the first group. that is Ta and Nb. an oxide film thicker than 0.2a is sufficient and the film can be obtained with relative ease in an acid. neutral or alkaline solution. With the second group metals. that is Zr and Hf.
  • oxide film thickness more than 0.35;; for Zr and 0.4;; for Hf is necessary.
  • film-forming metals of the third group. that is Al. Ti and others. a thickness of oxide films more than la is necessary.
  • the electrode could be prepared by chemically treating in an electrolyte which is mostly acid having moderate dissolving power against the oxide films (dilute sulfuric, nitric, chromic and oxalic acids being contained).
  • the fourth group metals consisting of alloys of oxide film-forming metals such as Ta. Nb. Zr.
  • the actual thickness of the oxide films should be greater than the summed products of thicknesses of oxide films and the contents with respect to all composing elements.
  • the fifth group metals which consist of alloys of one or more elements of the oxide filmforming metals belonging to groups 1 through 4 above such as Ta. Nb. Zr. Hf. Al and Ti as the major constituent with elements other than the oxide film-forming metals.
  • the thickness ofthe oxide films should be larger than product of the reciprocal of content of the major constituent and the minimum film thickness of the filmforming metals. In these cases the procedure to treat the oxide films may be similar to that for the oxide filmforming metal contained as the major constituent.
  • the process should be applicable to various metals. When applied to Al. zinc-plated iron plate. tinplated iron plate. Fe. tin-free sheet and many other materials. it should exhibit excellent performance and high coulombic efficiency as a process for electrodeposition painting.
  • Any desired resin type coating materials such as acrylic. polyester. alkyd. epoxyester and maleic oil resins could be applied with the high coulombic efficiency as could be encountered in the electrodeposition painting process by d.c.
  • Time required for the electrodcposition painting could be varied as desired. In other words. a coating layer of the desired thickness could be obtained within a certain time interval which is predetermined as desired.
  • ac voltage sources not only the commercially supplied sinusoidal a.c. source of or c.p.s. but also any a.c. sources of higher or lower cycles could be used for the purpose. Further. sawtooth or square wave a.c. could be satisfactorily used for the coating.
  • Table 2 shows the performance of the process of the present invention as a coating process applicable to various metallic materials including Al. zinc-plated iron plate, tin-plated iron plate. Fe and tin free sheet.
  • Aluminum oxide film electrode l(l.5 (/J.) thick oxide film [Conditions under which the electrodeposition coating was performed]
  • a counter-electrode of the same dimension cm X 10cm as a metallic material to be coated was placed at a 10cm distance from the latter in an electrodeposition painting bath.
  • the coating was conducted for 5 see. by the commercial a.c. (50 c.p.s. sinusoidal) of lOOV. and the coulombic efficiency was calculated. Subsequently. the corresponding coulombic efficiency for the d.c. coating was obtained when the same material was treated by electrodeposition painting process under application of 70V d.c. source in the same bath for 3 sec. using a stainless cathode. Ratio of the coulombic efficiencies shows the relative performance of the electrodeposition coating of each counter-electrode.
  • Acrylic resin the solid content of the bath being percent Bath temperature: C
  • the coulombic efficiency of the process of this invention was in all cases close to that of the d.c. method. and therefore the ratio in the coulombic efficiencies was lUO percent. Such values of coulombic efficiency were never obtained in the a.c. electrodeposition coating with electrodes other than the counter-electrode of the present invention.
  • this invention exhibits the high performance in the electrodeposition painting, as shown in FIG. 8, by using a.c. of a very wide range of frequency and, in addition to sinusoidal waves, by sawtooth or square waves shown in FIG. 9 with higher coulombic efficiencies than in other a.c. electrodeposition painting processes.
  • a third electrode is provided in addition of the metal to be painted by electrodeposition and the coupled electrode and is electrically connected to the metal to be painted by electrodeposition.
  • This modification of the present invention further enhances the advantages of the alternating current electrodeposition paint coating and particularly enhances the paint film quality.
  • the third electrode in the modification of the present invention has its objects to prevent gas generation at the metal to be painted by electrodeposition and to effect precision control of the paint film thickness, and is an oxide film electrode" or may be an ordinary electrode commonly used for electrolysis connected with a rectifying element of silicon, germanium selenium, etc.
  • H68. 6 and 7 which illustrate the deposition rate of the coating materials of this invention, show The oxide film electrode referred to above is composed of metals which form an oxide film such as Ta. Al, Ti. Zr. Nb. etc. or their alloys on which an oxide film is formed.
  • FlG. l0, 1 is a bath filled with clcctrodeposition paint.
  • 2 is an oxide film electrode used as a coupled electrode.
  • 3 is a metal to be painted by clcctrodeposition. connected to an alternating current source.
  • 4 is another oxide film electrode used as the third electrode connected to the side of the metal to be painted through a resistor 5.
  • the metal 3 to be paint coated and the third electrode are impressed with positive and negative voltages alternatively in respect to the counter-electrode 2.
  • an oxide film electrode is used for the counter-electrode. a large bath current passes under the bath voltage condition in which the counter-electrode is negative and the metal 3 to be paint coated and the third electrode 4 are positive. and clcctrodeposition paint coating is effected thereby.
  • the third electrode is the oxide film electrode. the current is hard to pass and passes mainly through the metal to be paint coated. thus using most of the current for electrodeposition paint coating on the surface of the metal to be paint coated.
  • FIG. 12 shows the relation between the ratio of the surface area a and the number of the pin holes in the coating film.
  • the solid line represents the relation before the baking and the dotted line represents the relation after the baking. From this figure. it is clear that the ratio a should be log 10 5.
  • connection of the third electrode to the metal to be coated may be preferably done through a variable resistor for better current balance between the third electrode and the metal to be coated. and in some cases for precision control of the amount of the electrodeposited paint coating.
  • the capacity of the resistor may be 0 200 K9 for presently available paints and it is enough if the resistor can flow the current corresponding to l0 percent of the bath current.
  • the third electrode is positioned up to 3/5 L(m) (corresponding to the slant lined portion in FlG. 14) from the metal to be coated supposing the distance between the metal and the counter-electrode is L(m).
  • the electrode has some measures such as perforation because ifa plate-form electrode is positioned in parallel the current for clcctrodeposition is hindered. From a point of equipment efficiency. a round bar form of electrode is preferred for stability and draining of the bath solution at the suspension of the operation.
  • FIG. 14 shows one example.
  • a rectifying element 107 such as of silicon. germanium. selenium. etc. and a variable resistor by orienting the rectifying element are connected is series in such a direction that the current flows in the direction 108 as shown in FIG. 15.
  • the capacity of the rectifying element or the resistor should be large enough to pass the current corresponding to l/10 of the bath current.
  • the electrode commonly used for electrolysis referred to above means an electrode of a metal which does not react with water such as stainless steel. lead. nickel. chromium. iron. silver. platinum. etc. or of nonmctallic material such as carbon.
  • the clcctrodeposition painting by a.c. of the present invention is a very excellent as well as practical process with a wide range of application.
  • a tantalum oxide film electrode having a 2700 A thick oxide film to be used in the process of this inven tion was prepared as follows: A 10cm X 10cm plate of tantalum was treated by immersing for 10 sec. in a mixed solution of H 80 HNQ, and HF in a ratio of 5 2 2. and an oxide film was formed on the surface by the anodic oxidation with a carbon cathode in a 15 percent boric acid solution at 70C. applying a voltage of about 5V at the beginning which was increased gradually up to V in 60 min. and maintained at the voltage for 20 min. Subsequently the plate was washed with water and then dried.
  • a 10cm X lOcm aluminum material placed at a distance of 10cm from the counterelectrode was coated by electrodeposition for 5 sec. using the commercial sinusoidal ac. voltage of 100V and 50 c.p.s. in a coating bath containing acrylic resin of the d.c. anode deposition type.
  • the coating material was deposited by 58.1 mg/dm" and the quantity of electricity involved in the treatment. as measured from the current form on an oscilloscope. was calculated according to the following expression. to be 3.09 couI/dm (see (iii) in FIG. 1).
  • the coulombic efficiency of the process of the present invention was 58.1 (mg/dm )/3.09 (couI/dm'-) 18.8 (mg/coul). which was equal to the coulombic efficiency in the d.c. electrodeposition coatmg.
  • Acrylic resin was the major constituent with the solid content of the bath being 15 percent.
  • EXAMPLE 2 An aluminum oxide film electrode (having 10.511. thick oxide film) to be used in the present invention was prepared as follows: A cm 10cm pure aluminum plate was kept for 3 min. in a 5 percent oxalic acid solution with a 5V voltage applied until the current decreased to a steady state. The voltage was then elevated. under the precaution not to change the current seriously. to 100V in about 60 min. Kept standing for 10 min., washed with water and dried.
  • a 10cm 10cm aluminum material placed oppositely at a distance of 10cm from the counter-electrode was coated by electrodeposition for 5 sec. using the commercial sinusoidal ac. voltage of 100V and 50 c.p.s. in a coating bath containing acrylic resin of the d.c. anode deposition type.
  • the paint material was deposited by 60.3 mg/dm COATING BATH OF ACRYLIC RESIN Major constituent Acrylic resin Solid content of bath: 1571 State of bath Emulsion type pH of bath 7.90 Bath temperature 20C Coulomhic efficiency in this bath by the d.c.
  • a titanium oxide film electrode to be used as counter-electrode of the process of this invention was prepared as follows: A 0.1 mm thick 10cm X 10cm foil of pure titanium was treated, after degreasing. with 2 percent hydrofluoric acid for 3 min. to dissolve impure oxide, electrolytically cleansed (with the current density 0.5A/dm in an aqueous solution containing 10 percent sulfuric, 7 percent phosphoric and 18 percent acetic acids.
  • a 10cm X 10cm aluminum material placed oppositely at a distance of 10cm from the counter-electrode was coated by electrodeposition for 5 sec. using the commercial sinusoidal ac. voltage of 100V and 50 c.p.s. in a coating bath containing acrylic resin of the d.c. anode deposition type. As a result, the coating material was deposited by 46.3 mg/dm".
  • the quantity of electricity involved in the treatment was calculated according to the following expression. to be 3.21 (coul/dm").
  • the coulombic efficiency in the electrodeposition coating by a.c. using the counterelectrode of this invention was 46.3 (mg/dm )/3.2l (coul/dm 14.4 (mg/coul).
  • the ratio of the coulombic efficiencies was calculated to be 76 percent by the following expression.
  • Ratio of coulombic efficiency Coulomhic efficiency in the process of this invention m0 Coulomhic efficiency in the dc. process A EXAMPLE 4 Using the tantalum oxide film electrode (with 0.27 thick oxide film) prepared according to Example 1 and a platinum electrode for the purpose of comparison counter-electrodes. electrodeposition painting was conducted by a.c. with the following four materials. Metal specimens to be coated by electrodeposition (10cm X 10cm. with one side sealed) 1. Bonde zinc-plated iron plate: Amount of bonde film (1.2 glm Amount of zinc plated (183 g/m 2. Tin-plated iron plate (ET No.
  • the amount of coating material The amount of coating material. the quantity of electricity required for the electrodeposition painting and the coulombic efficiency. or the amount of the coating material divided by the quantity of electricity. are shown in Tables 4 and 5 for the tantalum oxide film electrode and the platinum electrode. respectively, used as counter-electrode.
  • the quantity of electricity. the coulombic efficiency and the ratio in percentage of coulombic efficiencies are those obtained according to calculation in Examples l. 2 and 3.
  • Table 4 With a tantalum oxide film electrode as counter-electrode Bonderized Tin-plated Fe Tinzinc-plated iron plate (substrate free iron plate (ET No. for sheet 25) plating) Amount of coating material 60.0 62.0 (11.0 68.5 deposited (mg/dm") Quantity of electricity 3.19 3.30 3.24 3.614 (coul/d m") Coulomliic efficiency 18.8 18.8 18.8 18.8 (mg/coul) Ratio of coulombic lUU I00 100 efficiencies Table 5 With a platinum electrode as counterelectrode Bonderiled Tinplated Fe(subst- Tin- 7incplated iron plate rate for free iron plate (EIiNo.
  • an electrolytically tin-plated iron plate (commercially available tin-plated iron plate with plated tin by 0.24 lb/BB) of a dimension 10cm 10cm (one side sealed) placed at a 10cm distance from the counter-electrode by the commercial 100V. 50 c.p.s. sinusoidal a.c. voltage in a coating bath of acrylic resin.
  • Electrode of Electrode other than this invention of this invention Aluminum oxide Stainless steel Aluminum film electrode (SLS Z7Jelectrode (oxide film less than 0.2;; thickness) Coating material (10.9 .0 I18 deposited (mg/dm") Quantity olelectricity 3.22 7.0 6.0 teoul/dm l ('oulomhic efficiency I85) 0.3 ll (mg/coal) Ratio olcoulombic HRH) 2 l I efficiency n EXAMPLE 6 efficiency 14.x 6.2 17.8 12.5 (mg/coul) Using the tantalum oxide film electrode (having a mmr 027p.
  • thick oxide film prepared according to Example 1 l as counter-electrode.
  • an aluminum material having a 0. I 2y. thick oxide film
  • l0cm X l0cm one side sealed
  • EXAMPLE 7 from the counter-electrode was coated for 5 sec.
  • the aluminum Oxide film deem-Ode (having a clectrodepositionin4different baths ofcoating matcri- 4s 5, thick oxide fil appearing in Example 2 as ills f" Table 7 the commerclal 100V and counter-electrode.
  • Example 7 the coulombic efbath of a
  • the alu- Table 7 minu'm plate after the above treatment was washed with water. baked for 20 min. at 210C and then the Baths of coatmg materials (in outlme) amount of the coating material deposlted was mealf I AIR) sured.
  • the quantityof electricity passed was calculated as in Example 1.
  • Table 8 shows the results. The same coulombic efficiencies as those by the dc. method are obtained for seen in the table. Only the aluminum oxide film electrode of the process of this invention shows the same coulombic efficiency. 12.5 mg/coul. as by the dc. method.
  • Table 9 Present lnventive Electrode other than of the Electrode present invention
  • EXAMPLE 8 Using the tantalum oxide film electrode (having a EXAMPLE 9 Using the tantalum oxide film electrode (having a 2700A thick oxide film) prepared in the manner as described in Example 1 as counter-electrode.
  • a plate of electrolytically tin-plated iron (commercial material having tin plated in 0.24 lb/B.B) of a dimension 10cm X 10cm (one side scaled) placed oppositely against the counter-electrode at a 5cm distance was coated for 5 see. by the electrodeposition in an acrylic resin bath (the same as in Example 1 at a l00 ⁇ ' a.c. voltage by means of a source which generated sinusoidal a.c. of 20. 150. 300 and 600 c.p.s. The plate was then washed with water. baked for 20min. at 210C. and the amount of the coating material deposited was measured in mg/dm On the other hand. the quantity of electricity passed was measured as in Example 1. which gave the coulombic efficiency. The results are shown in Table l l. Apparently. sufficiently high coulombic efficiencies in the practical sense are maintained regardless of varied frequencies.
  • Amount of coating material deposited (mg/(1m 58.3 59.2 ML] 58. ⁇ Quantity of electricity passed (coul/dm] 3.1) U3 3.18 3.13 Coulombic efficiency 18.3 18.9 18.) 18.6
  • Example 1 0.27;/. thick oxide film prepared according to the pro- EXAMPLE l0 cess in Example 1 counter-electrode.
  • an electrolytically tin-plated iron plate (commercially available matcrial with an amount of tin-plated 0.24 lb/BB) of a dimension 10cm 10cm (one side scaled) placed oppositely at a distance of 10cm from the counter-electrode was coated by the elcctrodeposition for 5 sec. using the commercial I00. 200 and 300V a.c. voltage (50 c.p.s.) in an alkyd resin coating bath (bath temperature 20C. see Table 7). washed with water. baked for 20 min. at 210C. and then the amount of the coating material deposited (mg/dm was measured.
  • Table 10 shows the result. Obviously. the rate of deposition of coating material could be improved without lowering the coulombic efficiency by elevating the applied bath voltage.
  • the 'quantity of electricity passed Q was estimated as the difference of the quantity of electricity (0 0,,) due to current in phase with the applied bath voltage and the quantity of electricity Q,- due to current in inverse phase with the applied bath voltage.
  • EXAMPLE 11 A tantalum oxide film electrode having a 2.1a thick oxide film to be used in the process of this invention

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Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4051004A (en) * 1974-06-26 1977-09-27 Mitsubishi Rayon Co., Ltd. Electrodeposition coating method using alternating current
US4081344A (en) * 1975-01-20 1978-03-28 Nippon Steel Corporation Method for electrodeposition repair coating of the end of an easy-open can
US6607645B1 (en) 2000-05-10 2003-08-19 Alberta Research Council Inc. Production of hollow ceramic membranes by electrophoretic deposition
US20050260424A1 (en) * 2003-12-04 2005-11-24 Shimano, Inc. Corrosion resistant part and method for manufacturing same
WO2010034826A3 (en) * 2008-09-26 2010-09-10 Katholieke Universiteit Leuven, K.U.Leuven R&D Aqueous electrophoretic deposition
US20110139617A1 (en) * 2008-10-06 2011-06-16 Katholieke Universiteit Leuven, K.U.Leuven R&D Functional layers of biomolecules and living cells, and a novel system to produce such

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US3392101A (en) * 1963-07-26 1968-07-09 Goodlass Wall & Co Ltd Process of electrophoretic deposition using symmetrical alternating current
US3544440A (en) * 1963-06-15 1970-12-01 Hamburger Flugzeugbau Gmbh Process for coating conductive substrates
US3567612A (en) * 1967-10-26 1971-03-02 Grace W R & Co Electrolytic coating of n - 3 - oxohy-drocarbon-substituted acrylamide polymer

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US3544440A (en) * 1963-06-15 1970-12-01 Hamburger Flugzeugbau Gmbh Process for coating conductive substrates
US3392101A (en) * 1963-07-26 1968-07-09 Goodlass Wall & Co Ltd Process of electrophoretic deposition using symmetrical alternating current
US3567612A (en) * 1967-10-26 1971-03-02 Grace W R & Co Electrolytic coating of n - 3 - oxohy-drocarbon-substituted acrylamide polymer

Cited By (8)

* Cited by examiner, † Cited by third party
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US4051004A (en) * 1974-06-26 1977-09-27 Mitsubishi Rayon Co., Ltd. Electrodeposition coating method using alternating current
US4081344A (en) * 1975-01-20 1978-03-28 Nippon Steel Corporation Method for electrodeposition repair coating of the end of an easy-open can
US6607645B1 (en) 2000-05-10 2003-08-19 Alberta Research Council Inc. Production of hollow ceramic membranes by electrophoretic deposition
US20050260424A1 (en) * 2003-12-04 2005-11-24 Shimano, Inc. Corrosion resistant part and method for manufacturing same
US7244514B2 (en) * 2003-12-04 2007-07-17 Shimano, Inc. Corrosion resistant part
WO2010034826A3 (en) * 2008-09-26 2010-09-10 Katholieke Universiteit Leuven, K.U.Leuven R&D Aqueous electrophoretic deposition
US20110168558A1 (en) * 2008-09-26 2011-07-14 Jan Fransaer Aqueous electrophoretic deposition
US20110139617A1 (en) * 2008-10-06 2011-06-16 Katholieke Universiteit Leuven, K.U.Leuven R&D Functional layers of biomolecules and living cells, and a novel system to produce such

Also Published As

Publication number Publication date
JPS4837437A (enrdf_load_stackoverflow) 1973-06-02
JPS5117968B2 (enrdf_load_stackoverflow) 1976-06-07
GB1376761A (en) 1974-12-11

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