In purpose to observe the mechanism of the electrodeposition of the water soluble resins, some resins were prepared from ethylene-glycol and phthalic anhydride and were electro-deposited under different conditions. The following experimental results were obtained.
(1) There are an approximately fixed relationship between the dry weight of the deposited resin and the number of coulomb of electricity passed, and the dry weight of the deposited resin per Faraday varies with the condition of the electrodeposition.
(2) The quantity of the iron in the deposited resin is by far smaller in this experiment than that which should be expected to be contained in the deposited resin, if the polyester resin is deposited by Ferric ion mechanism.
(3) The deposited resin is easily resoluble in the solution, from which it is deposited.
(4) Some relationship exists between the dry weight of the deposited resin per Faraday and the carboxy-ic acid equivalent weight, which is equal to the weight of the resin, carried by the equivalent weight of carboxylic group. From the above experimental results, authors suppose that the following ionic reaction is the major reaction of the electro-deposition of the resins.
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