Method of forming multilayer coating films and multilayer coating films

A method of forming a multilayer coating film comprising

• the step (I) of coating an article to be coated with an electrodeposition coating followed by curing by heating to form an electrodeposited coating film,
• the step (II) of applying a water-borne intermediate coating onto said electrodeposited coating film to form an uncured intermediate coating film,
• the step (III) of applying a water-borne base coating onto said intermediate coating film to form an uncured base coating film,
• the step (IV) of applying a clear coating onto said base coating film to form an uncured clear coating film and
• the step (V) of curing said intermediate coating film, said base coating film and said clear coating film simultaneously by heating to thereby obtain a multilayer coating film,
• wherein said electrodeposition coating contains a particle A containing a resin (a) whose solubility parameter is δa as well as a particle B containing a curing agent and a resin (b) whose solubility parameter is δb and satisfies that
• (1) the value of (δb−δa) is not less than 1.0,
• (2) as regards the electrodeposited coating film formed from said electrodeposition coating, a resin film formed from said particle A shows a dynamic glass transition temperature of −110 to 10° C. and
• the resin film obtained by film formation from said particle A alone shows an elongation percentage of not less than 200% and
• (3) as regards the electrodeposited coating film formed from said electrodeposition coating, a resin film formed from said particle B shows a dynamic glass transition temperature of 60 to 150° C., and
• wherein the total amount of volatile basic substance in said uncured intermediate coating film and said uncured base coating film prior to carrying out the step (V) is not more than 7×10−6 mmol per coating film unit area (1 mm2).